- Montreal 2019
- Fredericton 2018
- Vancouver 2017
- London 2016
- Regina 2015
- Halifax 2014
- General / Générale
- CSCE 2014 General Conference / Congrès général 2014 de la SCGC
- Montreal 2013
- General / Générale
- Congrès général 2013 de la SCGC / CSCE 2013 General Conference
- 4th Construction Specialty Conference / 4e Conférence spécialisée sur la construction
- SMSB 2018
Papers - CSCE 2018 - Building Tomorrow's Society
Use of Granite Manufacturing Waste in Concrete Masonry Production (MA34)
Mohamed Abdeldaim - American University in Cairo, Mohamed Darwish - The American University in Cairo, Mohamed N. Abou-Zeid - The American University in Cairo, Ezzat Fahmy - The American University in Cairo, Mohamed Rashwan - AUC, Rafik Garas - American University In Cairo, Omar Mostafa - The American University in Cairo, Mohamed Abdaldaim - American University in Cairo, Bassma Elsobky - American University in Cairo, Omar Walelly - American university in cairo
The waste powder produced during granite manufacturing has been a source of significant pollution and health hazards. The use of this waste powder in concrete has been studied by several researchers. The current study involves partial replacement of the fine aggregates in the mix of concrete masonry by five different proportions of granite waste powder. Wet and dry tests on concrete are performed. The effect of varying the percentage of granite waste powder on the various properties of the produced masonry are assessed and compared to a control group with no powder involved. The mixtures having the highest strengths are determined and used to construct masonry prisms subjected to compression. The mix used to construct the prism surviving the highest compression is considered as the one adequate for future masonry production. The initial results indicate that incorporating such waste in walls can be one promising venue for its utilization in the construction industry.
Progressive collapse of low-rise buildings under wind loads (ST137)
Ahmed Elshaer - Lakehead University, Girma Bitsuamlak - Western Univeristy, Hadil Abdallah - Western University
Low-rise buildings are venerable to wind damage during hurricanes and other extreme wind events. Various experimental and numerical studies were conducted on low-rise buildings to evaluate and control the wind-induced loads. These studies considered wind to be acting on the external walls of buildings. This assumption can only be applicable for intact building envelopes. However, during extreme events, buildings may lose some non-structural components (e.g. windows and doors, roof tiles etc.), which will allow wind to enter the building envelope leading to alteration of flow field and redistribution of wind loads. Consequently, this transfer may subject the internal walls to additional lateral loads exceeding their typical load resistance capacities (i.e. internal walls are typically of lower capacities compared to external walls). Furthermore, failure of windward façade may expose the structure to higher wind loads due to an increase in drag or lift because of increase on the total subjected area to wind and changes on aerodynamics. On the other hand, as the collapse of components progresses to leeward faces, the channeling flow through the building may distract the wake formation reducing loads on exterior walls. The current study examines a four-story gable roof house subjected to a progressive collapse scenario. Computational Fluid Dynamic (CFD) simulations were used to study the aerodynamics at various progressive damage stages of the building for two different wind azimuths. In addition to the initial undamaged stage, three damage stages were considered. In the first two stages, building components in the windward direction were damaged allowing air to enter the internal spaces. While in the final stage, the damage reached the leeward components allowing the trapped air to channel through the building. The overall building loads and load sharing by various components of the building were assessed.
Properties of Spinned Steel and Bond Within Concrete (MA21)
Mohamed Abdel Moez - American University in Cairo, Hatem Sabry - American University in Cairo, Hossam Okasha - American University in Cairo, Omar Alaa - American University in Cairo, Hassan Dorgham - American University in Cairo, Mohamed Darwish - The American University in Cairo, Ezzeldin Yazeed Sayed-Ahmed - The American University in Cairo, Mohamed N. Abou-Zeid - The American University in Cairo
"Ductility of reinforced concrete sections is of paramount importance in Construction engineering applications, especially in the areas associated with seismic and impact loading. The presented paper aims to evaluate the effectiveness of Spinned steel bars used as reinforcement bars. An experimental program was performed to evaluate the bond strength of these bars within concrete and their ductility, strengths and toughness of Spinned steel bars. Several tests were initially conducted on the Spinned bars (tension, bending and scanning electron microscopy) to assess their properties and present its potential to be used in reinforced concrete elements. The experimental investigation results reveal that Spinned steel bars have higher bond strength with concrete compared to regular steel reinforcement. Nevertheless, Spinned steel bars showed tendency for higher energy absorption, which can suggest its future use in design of structures subjected to dynamic loading."
Calibration and Validation of Micro-simulation Models Using Measurable Variables (TR30)
Mostafa H. Tawfeek - University of Alberta, Mohamed El Esawey - Ain Shams University, Khaled El-Araby - Ain Shams University, Hatem Abdel-Latif - Ain Shams University
Traffic micro-simulation models have been extensively used to evaluate the impacts of traffic design alternatives. These models help stakeholders make informed decisions about any new change in the transport network. Calibration and validation of micro-simulation models are essential steps to ensure the reliability of the models. Most of the existing calibration efforts focus on experimental designs of driver behavior and lane changing parameters that have no physical meaning, or at least, cannot be easily measured. This paper suggests an approach for calibrating micro-simulation models using measurable variables. We advocate using an easy-to-understand, yet appropriate measures of the traffic stream such as spot speed as a calibration parameter. The approach was applied to a suburban corridor of about 12 km located in Greater Cairo Region. Video data were collected for about 9 hours on the corridor for both directions and were used to obtain traffic volumes and composition. Spot speeds were collected using a speed gun for a sample that comprised more than 2,000 vehicles belonging to different vehicle classes. VISSIM was used to model the corridor for only one direction that encompassed uninterrupted flow conditions. Spot speeds distributions were edited extensively in VISSIM to replicate the empirical distributions of the collected data. Furthermore, the distributions were developed for each vehicle type to achieve a higher level of accuracy. Statistical tests were carried out to ensure that the modeled speed distributions match the observed distributions. Corridor travel time was used as a validation parameter. Error measurements were computed for different analysis intervals (e.g., average travel time during a particular range), and it was shown that the validation errors decrease as the analysis period increases.
An Overview of the Recycled Waste Material Used as Partial Replacements of Aggregate in Concrete (MA69)
Mohamed Abdel-Raheem - University of Texas Rio Grande Valley, Moises Beas - UTRGV, Mohamed Allam - UTRGV, Cesar Tobias - UTRGV, Juan Gonzalez - UTRGV, Arlynn Rodriguez - UTRGV
Solid waste material has been a major concern around the world due to its negative impact on the environment. Over years, there has been a dramatic increase in the amount of solid wastes stored in disposal sites. In an attempt of minimizing the negative impacts of industrial wastes on the environment, many research have been conducted on the effect of these wastes when incorporated in concrete. The majority of the research in this area focused on the partial replacement of cement with these wastes. However, other studies investigated the replacement of fine and coarse aggregates with these wastes. This Paper presents a comprehensive summary for previous studies that focused on the partial replacement of aggregates in concrete with different industrial waste. The paper addresses the findings of these studies in an attempt of assisting future researchers identify useful alternative substitutes for concrete aggregates that enhance its characteristics and contribute to preserving the environment.
Initial Investigation of the Utilization of Steel Chips as a Partial Replacement of Coarse Aggregates in Concrete (MA68)
Mohamed Abdel-Raheem - University of Texas Rio Grande Valley, Moises Beas - UTRGV, Juan Gonzalez - UTRGV, Mohamed Allam - UTRGV, Cesar Tobias - UTRGV, Arlynn Rodriguez - UTRGV
The recycling of industrial wastes through its utilization in concrete has been lately on the rise. This is due to the fact that some of these wastes have proven to be useful in enhancing the properties of concrete. Previous studies have shown that the utilization of steel chips can be useful when used as a partial replacement of fine aggregates in concrete. This research study focuses on the utilization of steel chips as partial replacement of coarse aggregates. The study address the effect of steel chips on the compressive strength of concrete when replacing the coarse aggregates at different percentages. The results show that the compressive strength of concrete can significantly increase with the utilization of steel chips up to 25% replacement of the volume of coarse aggregates in the concrete mix.
Heat of Hydration of Calcium Sulfoaluminate Cement – A Literature Review (MA65)
Mohamed Abdel-Raheem - University of Texas Rio Grande Valley, Daniel Hernandez - UTRGV, Linda Navarro - UTRGV, Manuel Reyes - UTRGV, Grecia Silva - UTRGV, Luis Hernandez - UTRGV
Calcium sulfoaluminate (CSA) cement is a sustainable alternative to Ordinary Portland Cement (OPC). The manufacturing of CSA has a lower carbon dioxide emission compared to OPC. This is attributed to the lower temperature needed to calcinate the raw materials and less energy consumed during the pulverization process, which reduces the carbon footprint. However, in many cases, the production process of CSA can be more expensive that OPC. The Heat of Hydration (HH) of cement can affect the properties of concrete. In mass concrete structure, high HH can lead to thermal stresses and delayed ettringite that may lead to the expansion, thermal cracking, and failure of the structure. Several factors affect the of heat released during the hydration of cement, such as: the cement mineralogical composition, curing temperature, water/cement (w/c) ratio, and cement fineness. This study presents a comprehensive review of previous studies that focused on the assessment and quantification of the HH of CSA. This paper serves as a succinct yet comprehensive guide for future researchers that aim to conduct advanced studies on the HH of CSA.
Evaluation of the Effect of Fly Ash on the Cement Heat of Hydration According to ASTM C1702 (MA67)
Mohamed Abdel-Raheem - University of Texas Rio Grande Valley, Grecia Silva - UTRGV, Luis Hernandez - UTRGV, Linda Navarro - UTRGV, Michael Gomez - UTRGV, Jose Garza - UTRGV, Daniel Hernandez - UTRGV
In the construction of mass concrete structures, special attention should be given to the cement heat of hydration (HH). The amount of HH released can be substantial that it might compromise the integrity of the structure. Uncontrolled HH can lead to the formation delayed ettringite formation and thermal stresses that may lead to the failure of the structure. One method to control the HH is through the integration of pozzolanic supplementary cementitious materials (PCSM) in the concrete mix that are known to lower the HH. Previous research shows that Fly Ash (FA) can be an effective replacement of cement especially in mass concreting as it not only enhances the compressive the strength but also it lowers the HH. However, one study shows that heat released using FA class-C can exceed the HH of plain cement. As such, there is a need to investigate this discrepancy and verify the results. This study presents a re-evaluation of the effect of FA on the HH of a cement HH using a high precision isothermal calorimeter. Eighteen paste mixtures were made for two different types of cements replaced at different percentages using FA classes C and F. The experiments were conducted in accordance with ASTM C1702.
An Overview of the Effect of Fly Ash and Silica Fume on the Cement Heat of Hydration (MA70)
Mohamed Abdel-Raheem - University of Texas Rio Grande Valley, Jennifer CORTINA - UTRGV, Ofsman Quintana - UTRGV, Melissa Morales - UTRGV, Yahaira Marroquin - UTRGV, Dalinda Ramos - UTRGV, Sylvia Hernandez - UTRGV
Over years, the incorporation of pozzolanic supplementary cementitious materials (PSCM) in concrete have been increasing tremendously. Two of the most notable PSCM are fly ash (FA) and silica fume (SF), which have been proven to enhance some of the properties of concrete. Previous research shows that the use of PSCM in concrete serves many purposes. Several studies focused on the assessment of the ability of PSCM to reduce the heat released during the hydration process of cement when incorporated in the concrete mix. It is very desirable to minimize the cement HH especially in mass concreting as it may induce thermal stresses that may lead to the failure of the structure. This study focuses on the performance of FA and SF with respect to their effect on the cement heat of hydration (HH) as reported in the literature. The paper summarizes the most important findings of previous studies conducted on the effect of FA and SF on the HH, and shed the light on the conformity and discrepancies between different studies results. The paper should prove useful for future researchers and practitioners interested in studying the effect of FA and SF on the HH of cement.
Geogrid Reinforcement in Flexible Paved Roads (TR11)
Mai Ahmed - The American University in Cairo, Mennatallah Abdelhamid - The American University in Cairo, Sarah Sayed - The American University in Cairo, Safwan Khedr - The American University in Cairo, Tamer Breakah - The American University in Cairo, Maram Saudy - The American University in Cairo, Omar El-Kadi - The American University in Cairo, Mohamed N. Abou-Zeid - The American University in Cairo
The scope of this study is to explore and evaluate the effect of reinforcing the base layer in a flexible pavement section with bi-axial geogrids; using both large-scale experimental tests and numerical modeling using three-dimensional nonlinear finite elements analysis. A laboratory characterization for each layer of the pavement section according to a laboratory programs that included soil classification, tri-axial test, determination of asphalt concrete dynamic modulus for and CBR ratio for different elements in pavement section. A laboratory model of the pavement with and without the geogrids reinforcement, located at the middle of the base layer were constructed; And a dynamic loading scheme was applied on the experimental pavement model. Concurrently, a numerical model was developed to simulate the effect of such type of reinforcement on the pavement section in terms of the road’s performance enhancement and increase in its load-carrying capacity. After the verification of the numerical model by the lab-tested model, more simulated configurations were produced to explore the effect of using geogrid reinforcement on the pavement design with control performance criteria. The numerical model was proved to verify simulation of the pavement experimental model when comparing stress development throughout the pavement structure. Several design pavement schemes were analyzed by the numerical model to study the enhancement of the pavement performance.
Potential Implementation of Different Agro-wastes in Concrete (MA58)
Sara Boudali - Concordia University, Sameh Hassan - Concordia University, Ahmed Soliman - Concordia University, Sébastien Poncet - University of Sherbrooke, Stéphane Godbout - IRDA, Joahnn Palacios - IRDA, Bahira Abdulsalam - CIISolutions Composites Infrastructure Innovation Solutions Corp.
Concrete is the most widely used construction material. However, large volumes of natural resources and raw materials are being consumed in concrete production. This reduces concrete industry sustainability and increases its environmental negative impact. On the other hand, the agriculture sector is facing problems with agro-waste managements. Therefore, in this study, the potential of using different types of agro-wastes in concrete as a total/partial replacement of aggregate will be evaluated. Three types of agro-wastes, which are categorized based on the shape of waste to fibrous, fine and coarse, were tested. In addition, two types of binding materials, namely, ordinary cement and activated slag were used. Full characterization of different agro-waste and corresponding variations in compressive strength, density and microstructure were evaluated. Results showed that compressive strength will be directly affected by physical properties of the incorporated agro-waste and type of the binding material. Fibrous agro-wastes exhibited the highest strength with respect to other wastes. Successful use of such agro solid wastes as whole or partial replacement of natural aggregates contributes to energy saving, conservation of natural resources, and a reduction in the cost of construction materials.
Decision Support Framework for Urban Storm Water Drainage Infrastructure Management: Coupled GIS and System Dynamics Model (GC116)
Yekenalem Abebe - University of British Columbia, Solomon Tesfamariam - University of British Columbia
Storm water drainage infrastructures are composed of multiple subsystems that are geographically distributed and interdependent. All system components are expected to function based on their intended design capacity over the planning horizon. However, this is not the case due to environmental, physical and operational factors affecting their performance. Therefore, to maintain the required level of service, effective asset management system is crucial. This research tries to address the problem by proposing a holistic management approach using system dynamics and GIS applications. The proposed framework brings a single, unified way of investigating all asset components and their interaction in the management process. Furthermore, it can provide the platform to consider both space and time in the decision-making process. The framework is divided into three modules: the first module deals with the sewer network (pipes, manholes, and inlets/outfalls), the second module is for LID technologies (storage, infiltration, and filtration), and the last module deals with open channel flow routes (gutters, culverts, and ditches). The proposed framework is discussed in detail and a sample model for a storm water pipe network is presented. The model can be used to evaluate the current and future condition of asset components and plan appropriate interventions to improve the overall performance of the system. Furthermore, each management activity can be associated with a cost function to estimate the total life-cycle cost of the system.
Development of Probabilistic Cost Function for Flood Damage to Residential Structures (DM19)
Heather McGrath - Canada Centre for Mapping and Earth Observation, Natural Resources Canada, Miroslav Nastev - Geological Survey of Canada, Ahmad Abo-El-Ezz - Geological Survey of Canada, Natural Resources Canada
Risk models, which describe the relationship between hazard intensity and a damage ratio are increasingly used in flood risk management. Direct tangible damage resulting from flooding is typically computed based on the internationally accepted method of depth-damage curves. Depth-damage curves relate absolute damage (in terms of currency) or relative loss (percentage of the estimated total replacement value of property) to a given flood depth. Many depth-damage functions in use today are computed from synthetic data, where data are collected from a representative sample of buildings with similar properties in a floodplain during field surveys. A primary problem when assessing risk at an object-based spatial resolution using depth-damage curves is that these damage functions represent an average structure in the study location. There is great variability across any given structural class as well as variation within individual structures in a structural category (and across communities), for example, not all one-storey residences with basements are the same size, nor constructed of the same quality of materials and workmanship. The variability within a given class of buildings and the resulting depth-damage curve are often not transparent to the end user, thus damage estimates for individual buildings may be over/under estimated. In this paper, synthetic depth-damage curve data from communities in southern Ontario are used to develop probabilistic cost functions such that monetary damage estimates, as spent in Canadian dollars, and their likelihood of being exceeded at any given flood depth are more clearly expressed and communicated to end users.
Framework for seismic vulnerability of highway bridge networks (DM33)
Ahmad Abo-El-Ezz - Geological Survey of Canada, Natural Resources Canada, Nollet Marie-José - École de technologie supérieure, Heather McGrath - Canada Centre for Mapping and Earth Observation, Natural Resources Canada, Miroslav Nastev - Natural Resources Canada
In earthquake prone regions, the evaluation of seismic impacts on bridges is crucial to mitigation, emergency and recovery planning for highway networks. The degree of bridge damage determines the cost and time required for repairs and the level of post-earthquake functionality of the bridge determined by its capacity to carry traffic flow. The various losses of bridge functionality induce reduction or disruption of the transportation network, increase costs due to detour or reduced traffic flow and, what is most important, restrict access to emergency routes. This paper presents a framework for development and implementation of seismic vulnerability of highway networks. The proposed framework consists of the following successive models: hazard, exposure, damage and impact. The seismic hazard model generates spatial distribution of the shaking intensity for earthquake scenarios in terms of ground motion intensity measure (IM); the exposure model provides a database of bridge classes broadly defined with respect to their static and dynamic properties; the damage model assesses seismic performance of bridge classes in the network applying respective fragility functions represented as probabilistic relationships between the IMs and the simulated degree of expected damage; whereas the impact model evaluates the post-earthquake traffic-carrying capacity of the highway network based on the predicted damage including repair costs of bridges, road-closures and inspection priority. A case study of application of the proposed framework is presented for damage assessment of a hypothetical bridge network in Quebec City subjected to a magnitude M6 seismic scenario.
Delay Analysis Techniques in Construction Projects (GC52)
Hoda Abou Orban - The American University in Cairo, Ossama Hosny - AUC, Khaled Nassar - American University in Cairo, Rania Eltahan - The American University in Cairo
Delays are a common and major concern in most, if not all, construction projects, they often give rise to claims which could potentially lead to disputes. Therefore, it is crucial to be able to analyze the effect of delays on projects, in terms of both time and cost. A number of studies have been conducted to identify and formalize the root causes of delays in the construction industry; however, there isn’t an agreement on a specific delay analysis technique that each party should use when assessing time-related claims. Thus, the objective of this paper is to identify and critique the most commonly delay analysis techniques used by each party in construction and to recommend the appropriate techniques to be used in different project situations. A number of surveys and structured interviews were conducted on a pool of different project parties to identify and assess the industry commonly used techniques when assessing time-related claims and to highlight the leverages and limitations of each technique in the different situations. Thus, this research not only recognizes the most common delay analysis techniques used in the construction industry, but also explains the reasoning behind the choice of analysis technique by each party to the project. Finally, it supports decision-makers in selecting the most appropriate technique to be applied based on the project’s circumstances.
BIM-based Delay Analysis: A Framework (GC51)
Hoda Abou Orban - The American University in Cairo, Ossama Hosny - AUC, Khaled Nassar - American University in Cairo, Tarek Zaki - The American University in Cairo, Amir Hosny - The American University in Cairo, Khaled Zahran - American University in Cairo
Construction time-related claims are almost unavoidable in most if not all construction projects, they more often than not lead to major disputes. Therefore, the analysis of the delays’ impact on the projects’ time for completion is vital and could be performed using several delay analysis techniques that are available. Even though the literature is rich with in depth studies about the different delay analysis techniques, few research efforts targeted the utilization BIM technology in delay analysis. This paper presents a model for the measuring of project delays via attributing the amount of delays on the elemental level of the BIM project. The developed model uses an elemental graph generated for the BIM project that defines the construction logic in the form of dependencies between each of the model elements. Based on the generated elemental graph, the model then assigns the amount of delay of each of the BIM project elements from the total delay of the project and is also used to predict the total delay of the project based on the delay of one or more of the project’s elements. Results from this paper highlight the potential utilization of BIM in the assessment of project delays compared to the conventional schedule-based assessment methods.
Seismic Performance of Shear Controlled SRC Composite Comlumns In Existing Buildings (GC94)
Mayer Farag - The American University in Cairo, Mohamed N. Abou-Zeid - The American University in Cairo
Existing concrete buildings lacking seismic details are well known to cause the most losses during earthquakes so there is no wonder they are nicknamed the killer buildings. In every new earthquake we see more evidence of their vulnerability.
Ordinary building are taking the most intense of researchers from all over the world because of the majority of building are reinforced concrete. But one of the most famous structure building type which contains (SRC) composite columns. This type has been used since early of 1950 and now a day’s most high rise or non prismatic building are being built by SRC composite columns.
This Experimental study presented in this paper addresses the seismic performance of steel-reinforced concrete (SRC) composite columns experiencing shear and flexural failures using different concrete grades and confinement details to mimic both existing buildings with older construction details and modern buildings designed and built according to modern codes and construction practices. Test specimens represent exterior columns modeled based on a typical seismic design of a 35-story prototype new core wall-frame tall building and a 20-story prototype gravity existing building. The test parameters considered in this study are target failure mode, axial load ratio, percentage of longitudinal steel, structural steel section, concrete grade, and the transverse reinforcement volumetric ratio. The tests aim to characterize and compare the cyclic response of SRC columns with older and modern construction details. In particular, shear capacity, flexural capacity, residual axial capacity, deformation capacity and engineering demand parameters under different test variables are sought. Backbone curves for numerical simulation of seismic performance of SRC columns are presented. There are fourteen tested specimens divided to three group type; four specimens were tested as pilot, three specimens were tested representing modern building flexure deficient column and seven specimens for old building: five shear deficient specimens and two flexure deficient specimens. This wider work came with many conclusion and recommendations for older and modern buildings to overcome the deficiency of SRC composite column.
Effect of Mixing Water Temperature on Concrete Properties in Hot Weather Conditions (MA20)
Menna-t-Allah Assal - The Department of Construction Engineering, The American University in Cairo, Mohamed N. Abou-Zeid - The American University in Cairo
Environmental factors and hot weather conditions drastically impact the properties, strength and durability of concrete structures. Whereby, higher rate of slump loss, faster hydration with accelerated setting, reduced long term compressive strength and plastic shrinks are more common. Impact of mixing water temperature on concrete properties was thus studied being a key ingredient to the concrete mix, with direct impact on workability, strength and durability. Four mixes of variable cement content, minerals and admixtures were studied while varying the mixing water temperature at 5, 25 and 45°C to yield a total 12 different test sets. All other concrete ingredients were heated to 45°C simulating hot weather conditions. Two sets of results were analyzed starting with fresh concrete tests of slump, unit weight and temperature; in addition to hardened concrete tests of compressive and flexural strengths. Results showed an average 14% increase in the 28 days concrete compressive strength and reduced surface cracks in 5°C temperature water Vs. 45°C suggesting the strong impact of water temperature on concrete properties and need to add cooled water in hot weather. Further recommendations are provided in the study.
Electrically Conductive Concrete (MA9)
Dina Aboutaleb - The American University in Cairo, Reham Gohar - American University in Cairo, Kareem Ibrahim - American University in Cairo, Mahitab Mahran - American University in Cairo, Yomna Zaghloul - The American University in Cairo, Athnasious Ghaly - American University in Cairo, Ahmed Hamza - The American University in Cairo, Ahmed Hussam - The American University in Cairo, Eman El Nahas - The American University in Cairo, Mohamed N. Abou-Zeid - The American University in Cairo
Concrete has been known for decades as a non-conductive material. However, electrically conductive concrete is an innovative type of concrete, which incorporates conductive material to form a contiguous network of current flow. Such materials include graphite powder, steel shavings and steel fibers. This new mix offer a spectrum of applications such as de-icing on bridges and runways, cathodic protection, radiant heating and electromagnetic shielding. This study aims at exploring means to prepare conductive concrete together with achieving better understanding of the properties and performance of conductive concrete made with three potentially conductive materials at different dosages. To meet this objective, concrete mixes were prepared with various presumably conductive materials. The testing scheme includes conventional fresh and hardened concrete tests as well as specialized conductive and permeability tests. Results reveal that producing conductive concrete is possible through various means. However, care has to be taken that such mixes require thorough mixing and incorporation of materials. Initial findings suggest that conductivity is a function of both the type of the materials and dosage incorporated. The findings of this study are promising and should be built upon in order to propose such new concrete types in conductive media construction applications.
Utilizing Marble and Granite Waste in Portland Cement Concrete (MA8)
Nouran El Rashidy - The American University in Cairo, Hala Emam - The American University in Cairo, Rana Khalil - American university in cairo, Merna Naguib - American University in Cairo, Athnasious Ghaly - American University in Cairo, Mohamed N. Abou-Zeid - The American University in Cairo
Building Tomorrow’s Society
Batir La Societe De Demain
June 13 – June 16, 2018/ Juin 13 – Juin 16, 2018
Utilizing Marble and Granite Waste in Portland Cement Concrete
Emam, Hala 1, Naguib, Merna, El Rashidy, Nouran, Khalil, Rana, Awad Allah Yasmein, Ghaly, Athnasious, AbouZeid, Mohamed N.
1 Department of Construction Engineering, The American University in Cairo, Egypt
Abstract: Nano The waste of the marble and granite industry imposes an imminent environmental and health hazard thus creating various problems that impose as well high economic costs. Its production reaches multiple thousands of tons annually worldwide. Such waste could be utilized to replace aggregates in Portland cement concrete. Hence, it is vital to explore properties of such waste products in order to adequate incorporate it in concrete. In this work, Portland cement concrete mixtures are prepared using the solid debris waste of marble and granite to partially replace coarse aggregates at three dosages. In addition, three mixes using marble debris and slurry to replace both the fine and coarse aggregates is prepared to test the performance of the slurry. Together with conventional aggregates tests, concrete, fresh and hardened properties were conducted as well as permeability, chemical resistance, rapid chloride permeability, thermal insulation, and abrasion. In addition, a feasibility study exploring the means of incorporating such waste in terms of material and transportation costs as well as the costs of the health and environmental hazards is prepared and presented. Results reveal that use of these wastes can contribute not only to good quality concrete but as well to some superior properties.
Alkali-Activated Concrete (MA14)
Michel Bakhoum - The American University in Cairo, Salma Amer - The American University in Cairo, Amr El Mahallaoui - The American University in Cairo, Andrew Yassa - The American University in Cairo, George Fahem - The American University in Cairo, Ahmed Hussam - The American University in Cairo, Athnasious Ghaly - American University in Cairo, Eman El Nahas - The American University in Cairo, Ahmed Hamza - The American University in Cairo, Mohamed N. Abou-Zeid - The American University in Cairo
Concrete is the second most used commodity in the world after only water, it is also one of the most polluting materials to the environment. The production process of one ton of Ordinary Portland Cement (OPC) releases approximately one ton of Carbon Dioxide. Alkali-activation has been developed as a technique of combining various latently hydraulic cementitious matrices with an alkali to produce clinker-free binders in concrete mixes, therefore inhibiting the need for OPC. This study aims at using and comparing results from three different types of cementitious matrices, namely Fly Ash, quenched Ground Granulated Blast Furnace Slag (GGBFS) and air-cooled Blast Furnace Slag (BFS) with three different concentrations of the alkali-activator, a mix between Sodium Silicate solution and Sodium Hydroxide flakes. An average OPC mix has also been casted to be used as a control mix. It is important to note that all cementitious matrices used are found as byproducts of different industries; both BFS and GGBFS are byproducts of iron production and fly ash is produced from byproduct from burning coal in electric generation power plants. Conventional concrete tests have been performed, as well as two specialized tests; mortar bar and accelerated corrosion. Other tests have also been performed for the cementitious matrices including elemental composition, unit weight and fineness of the granules. Results reveal that concrete with unique properties, particularly in terms of early strength, can be obtained through the incorporation of alkali-activated concrete.
Use of Wood Waste in Construction of Curved Low-Cost Roofs (GC88)
Youssef Shaheen - American University in Cairo, Farah Safwat - American University in Cairo, Adel El Kassas - American University in Cairo, Youssef Helmy - American University in Cairo, Mina Fouad - The American University on Cairo, Abdelrahman Harb - American University in Cairo, Khaled Nassar - American University in Cairo, Mohamed Darwish - The American University in Cairo, Mohamed N. Abou-Zeid - The American University in Cairo
The waste produced during sawing wood has been a source of pollution and hazards for years. The use of such waste together with different binders in the production of engineered wood products has been studied by researchers for the past three decades. The current study involves performing several mixes of involving these wastes together with cement with different proportions. Standard strength tests are performed on the different mixtures produced to determine the mix having the best properties. Structural analysis and design of curved roofs made of the chosen mix are performed. Finally, a parametric study is performed to choose the shape and dimensions of the curved roof that minimizes the material cost of the roof.
Use of EVA Foam in Portland Cement Concrete (MA6)
Radwa Shoukry - The American University in Cairo, Aleya Farhoud - The American University in Cairo, Mennatallah Mansour - The American University in Cairo, Omar El Bagoury - The American University in Cairo, Shehab El-Akkad - The American University in Cairo, Ahmed Hussam - The American University in Cairo, Athnasious Ghaly - American University in Cairo, Eman El Nahas - The American University in Cairo, Ahmed Hamza - The American University in Cairo, Mayer Farag - The American University in Cairo, Mohamed N. Abou-Zeid - The American University in Cairo
EVA foam is a copolymer, composed of Ethylene and Vinyl Acetate, that is used in several industrial products. Some properties of EVA differ with the Vinyl Acetate percentage composition. However, all the variations of it are known to be lightweight, moisture resistant, chemical insulating, heat insulating and energy absorbent. During the manufacturing of EVA products, such as athletic footwear, swimming mats, etc., large quantities of EVA waste is generated. This waste is non-recyclable and poses various health harms when burnt, such as severe irritation to the eyes, skin and mucous membrane. Thus, it is currently being disposed of in landfills, as this deems to be the easiest way for manufacturers to handle the EVA waste. This study aims to assess the incorporation of EVA Foam as a non-recyclable; toxic solid waste in Portland cement concrete. Thirteen different mixes will be poured using different sizes of EVA Foam which are 9.5, 19 and 38mm. These sizes will be used as replacement for coarse aggregates by the following percentages 5,10,15 and 20%. These different mixes aim to determine the replacement size and percentage that yield the most adequate results in terms of strength. To arrive at such conclusion, the concrete mixes will be tested for their 7 and 28-days’ compressive strength, 28-days’ flexural strength, permeability and abrasion properties. Once identifying the most adequate percent replacement and size, concrete mixes with the selected replacements will then be tested further for other properties inspired by the original properties of EVA. They will be tested for thermal insulation, fire resistance, and modulus of elasticity. In light of the final results, the percent replacement will be recommended for the most applicable usage as well as the possibility of its use as porous concrete.
Damage due to abrasion in SCC containing different supplementary cementing materials (MA59)
Katherine Ridgley - Memorial University of Newfoundland, Ahmed Abouhussien - Memorial University of Newfoundland, Assem Hassan - Memorial University of Newfoundland, Bruce Colbourne - Memorial University of Newfoundland
This investigation evaluates and compares the abrasion resistance of various self-consolidating concrete (SCC) mixtures. Normal concrete (NC) mixture with higher coarse-to-fine aggregate ratio was also tested for comparison. Variable supplementary cementing materials (SCMs) were tested under the rotating cutter method for abrasion resistance. The effect of using different SCMs in SCC mixtures including fly ash, metakaolin (MK), silica fume, and slag on the abrasion resistance of SCC was examined. Results from the abrasion tests indicated that the SCC mixture containing MK had the highest abrasion resistance among all tested mixtures. The results also indicated that SCC mixtures showed improved abrasion resistance compared to NC mixture in terms of average wear depth and percent of weight loss.
Markov Chain-based long-term prediction of equipment usage from historical data (GC61)
Liu Chang - University of Alberta, Mostafa Ali - University of Alberta, Simaan AbouRizk - University of Alberta
The construction industry relies heavily on the use of equipment, with fleet management playing a critical role in optimal project delivery, particularly for general contractors. Reliable prediction of equipment usage can enhance acquisition or disposal decisions and, in turn, project performance. This study proposes a methodology for the long-term prediction of equipment usage, in consideration of potential variation in market conditions, using historical data from various sources. Regression models capable of predicting usage of individual equipment categories are developed. For longer-term predictions, a Markov Chain, used to simulate market fluctuations, is combined with the regression models. The proposed method can inform equipment managers of future fleet requirements for improved project planning and delivery.
Empirical Study of Correlation between the Cost Performance Index Stability and the Project Cost Forecast Accuracy in Construction Projects (GC97)
Amin Amini Khafri - University of Alberta, James Dawson-Edwards - Graham Construction Inc., Ryan Simpson - Graham Construction Inc., Liu Chang - University of Alberta, Simaan AbouRizk - University of Alberta
Earned value management (EVM) has been introduced as an integrated method to combine schedule, budget, and work breakdown structure (WBS). EVM provides various indices to demonstrate project performance, including the cost performance index (CPI). CPI is also used to forecast final project cost at completion based on the cost performance during project execution. Having a reliable prediction of the final project cost during execution can allow for the initiation of corrective actions that can enhance project outputs. CPI is not constant during project execution, and calculating the final project cost using a variable index is an inaccurate and challenging task for practitioners. Since CPI is based on cumulative progress values and because of the learning curve effect, however, CPI variation dampens and stabilizes as a project progresses. According to literature, a CPI is considered stable when the difference between the current and the final CPI is less than 0.1. While the 20% completion point is recognized as the stability point for military development projects, construction projects stability have not been studied.
Here, an empirical study using construction project data was conducted to establish the CPI stability point for construction projects. Surprisingly, none of the 10 preliminary projects analyzed were stable at the 20% completion point. Moreover, 70% of these construction projects only became stable on or after the 70% completion point of the project. To investigate the effect of CPI stability on cost forecast accuracy, the relationship between CPI stability and project cost at completion forecast accuracy was also investigated. Consistent with the findings regarding CPI, projects whose final cost was forecasted at 70% completion were found to be 90% accurate in 5 of the 7 project analyzed. Initial findings of this study have indicated that using CPIs obtained at the 20% completion point may result in unrepresentative final forecasts for construction projects and that using the CPI at a later completion point (e.g., 70%) may result in more reliable forecasts. Findings of this research are expected to be generalized upon the analysis of 20 additional projects from the same company.
Fuzzy-Based Method to Account for Subjectivity and Uncertainty in Bridge Condition Assessments (GC19)
Saleh Abu Dabous - University of Sharjah
Bridges are important element of civil infrastructure systems as they support the society and the economy on daily basis. In many countries, existing bridge infrastructure is aging and deteriorating and departments of transportation are paying attention to this growing problem. Bridge Management Systems (BMSs) have been utilized to select appropriate Maintenance, Repair and Replacement (MR&R) actions to maintain existing bridges within acceptable safety and serviceability limits. Bridge inspection and bridge condition assessment are important steps needed to make bridge management decisions. The main limitation of bridge condition assessment through visual inspection is the uncertainty inherent in bridge inspectors’ subjective ratings while using linguistic expression to quantify defects associated with the various bridge elements. This can significantly affect reliability of the condition assessment process. This research reviews the fuzzy logic and the stochastic analysis utilized in bridge condition assessment to account for uncertainty and subjectivity and proposes a combined method to address both limitations in bridge condition assessment. Then, a fuzzy based method for bridge deck condition assessment is proposed and demonstrated with a case study. The method benefits from both the fuzzy membership functions and the stochastic analysis to account for subjectivity and uncertainty in bridge condition assessment. The method can be validated further with more case studies to be accepted in practice.
A Clustering-Based Model for Rating Concrete Bridge Decks Using k-Means Technique (GC23)
Mohammed Alsharqawi - Concordia University, Tarek Zayed - The Hong Kong Polytechnic University, Saleh Abu Dabous - University of Sharjah
Bridge Maintenance, Repair and Replacement (MRR) decisions need accurate condition assessment and rating methods to ensure safety and serviceability of bridge infrastructure. In North America, the common practices to assess condition of bridges are through visual inspection. Further, the thresholds that define the severity of bridge deterioration are subjectively assigned based on the experience and judgment of the inspector or expert. The current research discusses the main deteriorations and defects identified during visual inspection and Non-Destructive Evaluation (NDE). NDE techniques are becoming popular in augmenting the visual examination during inspection to detect subsurface defects. Quality inspection data and accurate condition assessment and rating are the basis for determining appropriate MRR decisions. Thus, in this paper, a novel method for bridge condition assessment using the Quality Function Deployment (QFD) theory is proposed to develop an integrated condition rating index while identifying clear thresholds between the different ratings. The threshold identification technique is based on using k-means clustering. k-means is one of the simplest unsupervised learning algorithms that solves the subjective determination of threshold values problem. The QFD method was applied and the developed rating index was implemented on twenty case studies in the province of Quebec. The results from the analyzed case studies show that the proposed threshold model produces robust MRR recommendations consistent with decisions and recommendations made by bridge managers on these projects. The proposed method is expected to advance the state of the art of bridges condition assessment and rating.
Blast Loads on Structures (DM41)
Mohamed Elassaly - Fayoum University, Alaa Abu El Ella - Fayoum University, Mohamed Salem - Reinforced Concrete Construction Institute, Housing and Building National Research Center
Over the last decades, using of explosives by terrorist groups around the world that target high occupancy and public buildings is becoming a growing problem in the world. Explosive devices have become smaller in size and more powerful than some years ago. This would lead to structural failure or massive damage in the building. It also could result in extensive life loss or serious injuries. Terrorists usually use vehicle bombs in order to increase the number of injuries and fatalities and cause extensive damages to the property. This research examines the pressure time history that results from the explosion using the computer program Vector-Blast which is based on the blast wave characteristics of TNT scale. The research also presents a thoroughly documentation of the most significant terrorism events in Egypt that happened in government officials, police, tourists and the religious buildings. This would help in predicting future potential damages that could happen with different explosives types and quantities and different concrete structure parameters.
Enhancing Concrete Properties Using Nano Materials (MA71)
Ahmed Soliman - Concordia University, Ahmed Abubakr - Concordia University
As most sciences, material science was obviously affected by Nanotechnology and its promising applications. Many researchers had investigated the improvement in concrete mechanical and durability properties induced by nano-materials incorporation. This paper reviews the effect of various nano-materials on mechanical, durability and microstructure characteristics of concrete. It highlights the current development of applications of nano-materials in concrete. Moreover, it discusses the future potential implication of nano-materials in concrete. This will contribute to existed knowledge about nano-modified concrete and pave the way for wider acceptance and implementation in public infrastructures.
Soil-Structure Interaction Modeling of FRP Composite Piles (ST42)
Mostafa Abyaneh - Dalhousie University, Hany El Naggar - Dalhousie University, Pedram Sadeghian - Dalhousie University
In the recent years, fiber-reinforced polymer (FRP) composites have been found to have several applications in civil engineering due to their superior characteristics with respect to conventional construction materials such as concrete. Moreover, FRP composite can be used for piles providing many advantages compared with regular concrete piles including corrosion resistivity and application in corrosive environments such as marine applications. In this study, the mechanical behavior of concrete-filled FRP tube (CFFT) piles is predicted using an advanced numerical model to address their interaction with foundation soil under different lateral loadings. Nonlinear finite element analysis (NFEA) and disturbed state concept (DSC) is used to consider material and geometrical nonlinearity as well as interface of soil with FRP layer and concrete. Furthermore, the model is verified by applying the 3D finite element model to a full-scale field test. Also, a parametric study on pile diameter and length, soil properties, and concrete strength are presented to address various governing parameters in the design and analysis of CFFT piles. This is a research in-progress and more resets will be presented in full paper.
Soil remediation by integrating soil washing and advanced oxidation process (EN40)
Linlong Yu - University of Calgary, Mariana Brandao - Federal University of Sergipe, Gopal Achari - University of Calgary, Muhammad Faizan Khan - University of Calgary
Sulfolane is a polar organosulfur solvent well known for sweetening sour gas in the sulfinol process but also used to extract aromatics from hydrocarbon mixtures. Leaks and spills of sulfolane have occurred in the past and are still reported relating soil and groundwater contamination. So far, the only full-scale treatment technology for sulfolane contaminated soil is aerobic biodegradation which is limited by oxygen, nutrient and temperature. There is a need to develop an abiotic method to treat sulfolane in soil. Soil washing/soil flushing (SW/SF) processes integrated with post treatment technologies have been reported to effectively eliminate a number of organic pollutants, and can be potentially used to treat sulfolane contaminated soil.
In this paper advanced oxidation processes (AOPs) are selected due to its ability of degrading sulfolane in water, producing non-toxic by-products and complete mineralization. In contrast to aqueous spiked medium, the composition of wash water has other compounds that impact the treatment processes. This paper investigates the treatment of sulfolane contaminated soil by integrating soil washing/flushing and AOPs. Different AOPs including UVC/H2O2, UVC/O3,UV/O3/H2O2, O3/OH- and Fenton were studied. Results have shown that sulfolane can be effectively removed from the soil using water as a washing/flushing solvent. Furthermore, the sulfolane in the soil washing/flushing solution were also effectively degraded using appropriate AOPs.
Removal of sulfolane from water using activated carbon adsorption (EN39)
Yiqiao Yang - University of Calgary, Linlong Yu - University of Calgary, Sobhan Iranmanesh - University of Calgary, Gopal Achari - University of Calgary, Ian Keir - Bonavista Energy Corporation
Sulfolane is an industrial organosulfur solvent, mainly used to extract aromatics and process sour natural gas. Leakages, spills and disposal of waste containing sulfolane have led to groundwater and soil contamination near gas plants in North America. Due to its high miscibility in water, sulfolane can travel long distances and cause off-site contamination. The limited toxicological data show that sulfolane can be a potential hazard to human and environment. In response to this, companies are willing to take action to remediate sulfolane contaminated soil and groundwater.
Activated carbon adsorption is a mature technique widely applied in water and wastewater treatment. Activated carbon can remove organic matter from water through physical and chemical interaction on its porous surface. This paper investigates the removal of sulfolane from aqueous media by using commercially available activated carbons. The performance of activated carbons from different raw material and with different particle sizes on sulfolane removal was evaluated. The best activated carbon was selected for further optimization which included studies involving the impact of pH, temperature, water quality and co-contaminants.
The laboratory findings showed that activated carbons are capable of removing sulfolane from aqueous media. Among different activated carbons, the coconut shell based activated carbon exhibited the highest sulfolane adsorption. The optimization study indicated that the presence of co-contaminants can significantly impact the performance of activated carbon in removing sulfolane.
Incorporating Environmental Performance in Network-level Pavement Maintenance Program: A systematic review (GC17)
Jessica Achebe - University of Waterloo, Susan Tighe - CPATT - University of Waterloo
The reduction of material consumption and greenhouse gas emission when maintain and rehabilitating road networks can achieve added benefits including improved life cycle performance of pavements, reduced climate change impacts and human health effect due to less air pollution, improved productivity due to optimal allocation of resources and reduced road user cost. This is the essence of incorporating environmental sustainability into pavement management. The functionality of performance measurement approach has made it one of the most valuable tool to Pavement Management Systems (PMSs) to account for different criteria in the decision-making process. However measuring environmental performance of road network is still a far-fetched practice in road network management, more so an ostensive agency-wide environmental sustainability or sustainable maintenance specifications is missing. To address this challenge, this present research focuses on environmental sustainability performance of network-level pavement management. The ultimate goal is to develop a framework to incorporate environmental sustainability in pavement management systems for network-level maintenance programming. In order to achieve this goal, this paper present the first step, intention is to review the previous studies that employed environmental performance measures, as well as the suitability of environmental performance indicators for the evaluation of the sustainability of network-level pavement maintenance strategies. This paper provides a brief forward regarding the environmental sustainability performance metrics and challenges to integrating measures into pavement management decision making. Next step will involve an industry and agency survey to identify the state-of-practice in environmental performance measurement, highlight data available and data needed, and propose the framework to incorporate measures into network-level sustainable maintenance and rehabilitation programming.
Toward a Greener Construction: Development of Alkali Activated Grout (MA40)
Adeyemi Adesina - Concordia University, Ahmed Soliman - Concordia University
This study focuses on the development of an alkali-activated grout with acceptable fresh and hardened properties to satisfy its use for various construction application. The effect of different factors including activator type, water to aluminosilicate ratio, Slag to sand ratio; percentage of superplasticizer and viscosity modifier on flowability, setting time, bleeding, and compressive strength of the grout were evaluated. It was observed that the use sodium silicate to activate slag leads to a very faster setting time, and lower flowability even at a high percentage of superplasticizer. The grout produced by the activation of slag with lime and 1% superplasticizer shows good flowability, but segregation was observed. Viscosity modifier was needed to counteract the segregation, however, it had decreased the flowability of the activated alkali grout drastically. The overall result of this experimental study shows that the right combination of the optimum level of superplasticizer, viscosity modifier and slag to sand ratio would help to achieve a flowable grout with good strength.
Properties of Alkali Activated Mortar Incorporating Recycled Concrete and Ceramic Waste as Fine Aggregate (MA53)
Adeyemi Adesina - Concordia University, Ahmed Soliman - Concordia University
Despite the development of alkali activated composites to produce a greener composite for building purposes, the strain on natural sources of aggregates continues. The strain on these natural deposits of aggregates is as a result of high construction demand. To achieve a more sustainable alkali activated composite, it is essential to find more ways to replace the aggregates with waste materials. This experimental study was carried out to observe the possibility of using recycled concrete and ceramic waste as fine aggregate in alkali activated mortar. The binder used in this study was slag, and activated with sodium silicate and hydroxide. Fine aggregates for the mortar was replaced with 25%, 50%, 75% and 100% recycled concrete and ceramic waste. The sodium silicate to sodium hydroxide ratio was fixed at 2.5, and water to geopolymer solid ratio in the range of 0.45 to 0.55 was used. The mechanical properties along side with the physical properties were explored to determine the optimum level to which fine aggregate in alkali activated mortar can be replaced.
Formulation of Hydraulic Cement from Nigerian Seashell and Staple Crop Husk Powders (GC129)
Damilola Oyejobi - University of Ilorin, Ilorin, Nigeria, Sabur Raji - University of Ilorin, Adeyemi Adesina - Concordia University, Olaitan Alabi - University of Ilorin
Cement clinker compounds are basically formed from the reaction between silica and calcium oxides to form C-S-H hydrate. This study blends the enormous agricultural waste products of seashells and staple crop husk powders in different mix proportion in order to form new cement material. The chemical analysis revealed seashells and staple crop powders contained over 80% calcium and silica oxides respectively. This work further investigated the production of cementitious materials that will conform to Portland cement without any need for chemical activation and heat curing as a practice in alkali-activated cementing material. Some of the physical requirements and chemical composition required for the cement and cement compounds were conducted for this new blended cement material. This is followed up with full replacement of cement in mortar and paste tests for the determination of optimal strengths and fresh properties. The benefits of this study include reduction in the green-house gases, re-use of waste products for economic value and better cement properties.
Keywords: Cement clinker, waste products, blended cement, heat curing, alkali-activated, optimal strength
Vulnerability Assessment of Water Supply Network Against Seismic Hazards: A case study in Vancouver (ST82)
Sudipta Adhikary - Concordia University, Fuzhan Nasiri - Concordia University, Ashutosh Bagchi - Concordia University, Montreal, Canada
The recognition of vulnerability in water distribution system is a critical aspect regarding infrastructure resilience evaluation. Water supply system is represented as a complex network of interconnected distribution mains and nodes spatially distributed over a large area. This study proposes a method of resilience analysis of the existing pipelines in water distribution system for Vancouver, British Columbia as a function of failure in pipelines or repair rate for common seismic hazards incorporating the seismic vulnerability index applied in a Geographical Information System (GIS). The paper presents an outline of quantitative assessment of risk, based on the identification of governing parameters influencing the pipeline behavior, particularly for West Point Grey, Vancouver, BC as the area is prone to high seismic attacks. The pipeline behavior is considered as a function of parameters like pipe diameter, length, and materials, etc. which are demonstrated having a coefficient. They represent individual influences on the links connected to nodes of the system, and the seismic vulnerability of each pipeline is determined using empirical formulas in context with transient ground deformation (TGD), permanent ground deformation (PGD) and liquefaction impacts. The concept of integrating the Vulnerability Index (VI) with damage rate with a graphical map is to carry out a clear understanding of the efficiency of emergency response of each element in the system and prioritizing the potential pipeline candidates for replacement. This method will allow adopting a risk-based strategy to withstand seismic vulnerabilities in the water system of Vancouver.
Keywords: Water Supply Network, Resilience, Seismic Hazards, Pipeline Fragility, Reliability
Effect of temperature on electricity production in a closed-loop pressure retarded osmosis (PRO) process (EN18)
Suman Adhikary - Concordia University, Md. Shahidul Islam - Concordia University, Amruthur Ramamurthy - Concordia University, Saifur Rahaman - Concordia University, Sormin Sultana - Concordia University
The search for sustainable and environmentally friendly energy sources has been ramped-up by an ever-increasing global demand for energy as well as the need to reduce dependency on fossil fuels. Closed-loop pressure retarded osmosis is an integrated system of pressure retarded osmosis (PRO) with a thermally driven separation process feasible for recovering draw solutions. Harnessing pressure gradients (i.e. salinity gradient) via PRO is a promising technology for non-greenhouse emitting renewable energy production. Feed and draw solution temperature has an influence on water flux and, therefore, the temperature can play a significant role in overall electricity production via PRO. In order to investigate the effect of temperature on PRO process, this study primarily examines the impact of temperature on electricity production. Using 1 M NaCl as draw solution, an increase in power density of ~34% (from 6.7 Wm-2 to 9.0 Wm-2) was observed when the feed solution temperature was raised from 200C to 400C in a PRO process using commercial thin-film composite (TFC) membrane.
Integrating Quality into Earned Value Management (GC38)
Reem Ahmed - Concordia University, Mohamed Afifi - McGill University
The Earned Value Management (EVM) is the most commonly used system in construction projects allover the world to integrate both time and cost controls of a project. However, numerous researchers have identified gaps and limitations to using this method. The most agreed-upon limitation in using the EVM, is that it does not incorporate the quality aspect of a project, although it is one of the main drivers of success in any project. As a result, this study was conducted as a contribution to efforts in this field with the aim of identifying a proper way to integrate quality, time and cost using the EVM. A framework was developed to assess the quality of a project by the means of proposed equations and formulae that hopefully will aid project managers and responsible parties in a project in having a broader vision of the project's performance in terms of time, cost and quality. Furthermore, a case study from an actual construction project was analysed to verify and validate the framework, and the results were in favor of using the framework rather than the conventional EVM calculations.
Durability of Internally cured concrete using Recycled Concrete Aggregates: Experimental & Feasibility Study (MA33)
Mohamed Afifi - McGill University
Concrete curing is of paramount importance in order for concrete to meet performancerequirements. Conventionally, curing has been conducted by means of water sparkling, wet burlap or a curing compound. For performance and environmental reasons, internal curing has been gaining increased attention. However, more data is needed for the effectiveness of this curing technique when used in various concrete mixtures. This investigation addresses potential utilization of internal curing in high performance concrete (HPC). Internal curing was introduced by means of recycled aggregates incorporated into HPC mixtures. Conventional mixtures were prepared and were thoroughly cured either by water or by a curing compound or left non cured. Fresh concrete and Hardened concrete properties were assessed including slump, unit weight, compressive and flexural strength, and durability tests as shrinkage assessment, rapid chloride permeability test (RCPT) and abrasion resistance. Experimental work is backed up with a simplified feasibility analysis with case study, incorporating initial and future costs to better judge potential of this technique. The outcome of this study uncovers that the addition of pre-wetted recycled concrete aggregates can prompt an enhancement in concrete workability and durability accompanied by a reduced shrinkage. Compressive and flexural strengths decreased with the increased replacement dosages, however several dosages were tested to reach a figure of optimum replacement. Results of this study reveal the potential of this technology in saving fresh water as well as the costs saved in maintenance and rehabilitation works.Keywords: (Internal, Curing, High Performance, Concrete, Recycled)
Flood Early Warning Systems, Misconception and Challenges - The Case of Colombia (DM12)
Alonso Aguirre Fandiño - Universidad Nacional de Colombia Sede Manizales, Camila Lopez Vasquez - Universidad Nacional de Colombia Sede Manizales, Maria Alejandra Osorio Castro - Universidad Nacional de Colombia Sede Manizales, Leonel de Jesus Rivera Grisales - Universidad Nacional de Colombia Sede Manizales, Julieth Alejandra Toro Morales - Universidad Nacional de Colombia Sede Manizales, Philippe Chang - Universidad Nacional de Colombia Sede Manizales
In Colombia highly populated urban centers are located in extremely mountainous terrain. Overall the territory located in the Andean mountain range presents a relief characterized with steep slopes and deep valleys. Furthermore, high climate variability associated with the intertropical zone causes extreme rainfall events throughout the year.
Over the mountain range, intense precipitations over steep terrain promptly saturates the watershed and causes overland flow to rapidly concentrate in natural channels in rivers. The sudden rise of the waterline along the riverway threatens vulnerable populations including risk to infrastructure and personal property.
Preventive measures to such treat include the implementation of early warning systems in local communities in order to mitigate risk and limit damages.
In order to implement such systems a correct and detailed understanding of the watershed is required including geomorphological parameters and historical rainfall data series in the area allowing one to correctly determine alert thresholds.
This study reveals how standard protocols developed in North America and Europe in the implementation of early warning systems have shown limited success in Colombia where often limited and/or incomplete data series are available, hydraulic modeling softwares are generally ill adapted to the characteristics of the terrain, and watershed response time requires real-time analysis and/or precipitation model prediction. Difficulties in model calibration and alert threshold determination are also brought into question.
Dynamic Analysis of Profiled Steel Sheet Dry Board Composite Floor Panel (ST97)
Ehsan Ahmed - Thompson Rivers University
Profiled Steel Sheet Dry Board (PSSDB) composite panel has been proven to be an effective structural system and can be exploited for a variety of structural purposes. As a flooring system, the PSSDB floor carries the out of plane bending and shear mainly in the direction of corrugation of profiled steel sheeting. For such flooring system, human induced vibrations are becoming increasingly vital serviceability and safety issues. In this paper, investigations are carried out on the vibration performances of the PSSDB floor panel. Numerical analysis using a commercially available FEA code is carried out to evaluate the performance of single span panel subjected to human induced vibration. It also establishes the Dynamic Amplification Factors (DAFs) for displacement and acceleration responses. It is observed, closer spacing of connectors in PSSDB panel and increasing the thickness of dry board significantly reduced the peak acceleration of the system. Also, vibration characteristics can be improved by increasing the amount of damping of the floor system.
Keywords: Profiled steel sheet, dry board, vibration, DAF’s, and flexural rigidity.
Optimization of Single-lane Roundabout Geometric Design: Environmental Sustainability (TR28)
Hend Ahmed - Ryerson University, Said Easa - Ryerson University, Canada
Intersections are a significant source of congestion which produces the majority of vehicle emissions; therefore, environmental sustainability is the primary objective of intersection design. Research has proven that roundabouts provide an effective solution to calm traffic and improve the environmental impact of intersections. This study presents a model that directly identifies the optimal geometric parameters of a single-lane roundabout in order to minimize vehicle emissions. The model is based on an optimization technique which uses environmental sustainability as a design objective. The Vehicle Specific Power (VSP) methodology was used to model the vehicle emissions of approaching vehicles based on an operation speed model. The traffic conditions, site limitations, and guideline recommendations were used as inputs and the optimal geometric parameters that minimize vehicle emissions were the decision values determined by the model. A sensitivity analysis was conducted and revealed that the model improved environmental sustainability, providing reductions in vehicle emissions.
Flood risk assessment in Canada: Issues of purpose, scale, and topography (DM29)
Amin Elshorbagy - University of Saskatchewan, Raja Bharath - University of Saskatchewan, Mohamed Ahmed - University of Saskatchewan
Flood risk assessment in Canada is a top priority in both science and policy agendas. Recent flood damages have caused the national economy billions of dollars. Fluvial and pluvial flood assessment, which is the focus of this presentation, requires reliable flood mapping in Canada, which in turn raises issues regarding purpose, scale, and topography. Large scale planning of developments, landuse change and zoning, or specific engineering design are examples of different purposes that entail different scales for flood mapping. The different topographies across Canada also dictates different approaches for flood modeling and mapping.
A national flood risk assessment in Canada, using fine resolution global and national datasets, is presented. A national flood-prone area map was prepared using a 20m resolution DEM to identify, for each pixel, the distance from and the height above the nearest river. An exposure map was prepared by using landuse and the satellite-based nightlight data to determine the value of the flood-prone pixel. A national economic flood risk map was then produced, and subsequently overlaid with population density information to produce a socioeconomic flood risk map for Canada. The reliability of these maps was also evaluated. These maps may prove important to identify critical areas prone to floods for any location in Canada.
At local scale, where more detailed flood hazard, rather than flood-prone, is needed, hydraulic models were developed to better map the flood extent that corresponds to specific flood quantiles. A probabilistic flood hazard map (PFHM) for a river reach was produced by perturbing input and model parameters within expected ranges of uncertainties using a combined 1D/2D hydrodynamic model in the Qu’Appelle River basin, Saskatchewan. PFHMs help visualize uncertainty in the flood extents and assign a probability of inundation in the floodplains. The Qu’Appelle river basin also provided an opportunity to study the impact of lake management on floods as there are eight controlled and uncontrolled lakes along the river. The effect of perturbing lake levels on downstream flooding was determined and the optimal water levels that minimize the flood extent were identified.
Finally, the common prairie pluvial flooding due to poor drainage and water ponding in depressions was modeled using new modeling framework based on cellular automata. This framework enables determining the quantity and the overland path of surface runoff, and it shows potential in predicting flooding patterns and the actual connectivity between land depressions using terrain data.
Risk Allocation Framework to Minimize Disputes in Construction Projects: Case Study of Egypt (GC37)
Reem Ahmed - Concordia University, Ayman Nassar - German University in Cairo
Risks are generally defined as the variations in the possible outcomes that exist in nature for given situations. Construction projects in Egypt always experience high levels of risks and uncertainties due to their complex and dynamic environments. This, in turn, impacts projects in both time and cost and causes numerous disputes between parties. Usually, project participants allocate risks by aversion where owners tend to shift risks to the primary contractor, who in turn transfers them to the subcontractors. As a result of this, risks are not necessarily allocated/ re-allocated to the party that is best able to manage them efficiently and effectively. So as a step forward in the approach of mitigating these risks and decreasing their negative effects, an extensive literature review was conducted to indentify the most prominent and evident risks in the construction industry in the Middle East and especially in Egypt. These risks were validated and more risks were gathered by the means of experts' one-to-one interviews. And then, a framework to properly allocate those risks to the most suitable party was developed by the aid of a survey questionnaire that was formed to assess the perceptions of experts in the construction field including owner representatives, contractors, as well as consultants on risk allocation. The allocation of each risk was either in favor of the owner, the contractor, or to be shared between both parties. The survey also assessed two other factors; the risks’ frequency in the construction process and the risk significance in causing construction disputes. The results were gathered from the respondents and were analyzed. Moreover, six actual construction projects in Egypt were used as case studies to validate the framework and the results were in favor of the framework developed.
Applicability of Wastewater Usage in Concrete Production (GC36)
Reem Ahmed - Concordia University, Tarek Hashem - German University in Cairo
Concrete is the most widely used construction material in the world and is considered one of the largest water consuming industries as approximately 150 liters of water is required per cubic meter of concrete mixture. Recently, population explosion coupled with urbanization has raised the demand for water resulting in its scarcity making water a critical environmental issue that is limiting water supplies and water quality worldwide. On the other hand, with industrialization, the quantity of wastewater generated has soared up warranting appropriate measures for utilization and disposal. An attempt has been made in this direction towards utilization of industrial effluents in construction industry. This study was conducted to investigate the possibility of saving water used in concrete mixtures and make use of produced wastewater domestically and industrially. Non-treated effluents from 7 different factories have been used as mixing water in mortar mixes utilized for preparing 50mm mortar cubes. Effluents had high concentrations of ceramic powder (in case of ceramic factory), marble powder (in case of the stone-pit and marble factory), and sugar (in cases of halva, jam and ice-cream factories). Compressive strength of cubes was tested after 3, 7 and 28 days. Values of compressive strength of control samples (prepared with tap water) have been used for comparison.
Investigation of Discharge Coefficient for Siphon Spillway (GC90)
Warda Ahmed - Concordia University, S. Samuel Li - Concordia University, Ramamurthy Amruthur - Concordia University
Flow control is an important hydraulic engineering application. Various types of spillways may be used to release an excessive amount of water from a reservoir in order to protect the reservoir and surrounding areas. For this purpose, siphon spillways are attractive because of their great ability to pass full discharges with a minimum increase in the upstream head. They have been extensively used as an efficient flow-control structure in open channels. The design of siphon spillways requires reliable estimates of the relationship between discharge and the difference in water levels on the upstream and downstream sides. Such relationship involves a discharge coefficient. This is a key parameter for the design of siphon spillways. This paper aims to investigate the discharge coefficients under the conditions of submerged water flow at the outlet of the flow passage. Siphon discharges under submerged conditions have not been thoroughly investigated in the past. This paper combines computational fluid dynamics (CFD) with laboratory experiments. Computations of two-phase flow have been performed for a range of Reynolds numbers. A physical model of siphon spillway has been fabricated and tested at Concordia University. It was incorporated into a rectangular recirculation flume of 30 cm wide, 10 m long, and 100 cm high. The shape of the spillway’s crest is a circular arc with a conduit depth of 5.75 cm. It has a tangent section with a deflector and a rectangular exit. Laboratory experiments produced point gauge measurements of upstream and downstream water levels, and V-notch measurements of flow rate. The experiments covered a wide range of hydraulic heads, resulting from different combinations of upstream and downstream water levels. These measurements are used to determine experimental values for the discharge coefficient. To extend the experimental results, the dependence of the discharge coefficient on the dimensionless head is predicted through CFD modelling. The CFD modelling was implemented in a two‐dimensional siphon spillway. The suitability of the RNG k‐ε model and standard k‐ε model for turbulence closure in CFD modeling of the highly curved flow was compared. The experimental results are used to validate the CFD predictions. They agree well with the experimental data. Under submerged flow conditions, the discharge coefficients fall in the range of 0.62–0.70. The variations appear to follow the trend of the discharge coefficient curve under free flow conditions, previously reported.
Performance Evaluation of a Four-legged Intersection using Microscopic Simulation Model (TR31)
Muntahith Orvin - Military Institute of Science and Technology (MIST), Afia Siddika Ivy - Military Institute of Science And Technology (MIST), Hadiuzzaman Hadi - Bangladesh University of Engineering And Technology, Hasib Mohammed Ahsan - BUET
Traffic congestion is a widely spreading problem through the world which is mainly observed around intersections in urban areas. The gap between traffic demand and supply is increasing day by day that makes urban intersection not only a node of urban traffic network but also a traffic congestion spot. The evaluation of intersection performance is one of the research emphases on urban traffic and performance of intersection has also been studied for a long time. In this study, a four legged intersection has been evaluated that suffers from high congestion especially in the morning and evening peak hours. The traffic within the study area is mostly heterogeneous with non-lane based flow. Simulation models have been proved to be accurate tools in the evaluation of intersections. Therefore, a microscopic simulation model has been used to assess the performance of the current intersection. Using VISSIM the simplified version of on-field condition is replicated with a view to observing and predicting the behavior of the prevailing system. Several traffic data including vehicle composition, turning movement at intersection, vehicle count, queue length, cycle time, green time, red and amber time, number of lanes, travel speed, travel time etc. are collected from the study area. The simulation model is calibrated with the field data and validation of the model with field data signifies that the developed model clearly mimics the reality. Then, different alternatives have been implemented using as well as modifying the developed model. The intersection model is analyzed for several conditions such as no signal control, 2-phase and 4-phase signal control. From the study it is found that travel time for modified 2-phase and 4-phase both are more favorable than the existing 2-phase signal condition. Moreover, delay result is more conducive in modified 2-phase system than the 4-phase and existing 2-phase signal condition. But it is to be noted that the 4-phase signal design produces maximum average queue length. The congestion, delay, environmental pollution and high energy consumption become a serious threat to urban sustainability with the growth of traffic in the existing road system at an alarming rate. The signal design modification can be a great solution to the existing congestion condition prevailing in the studied intersection. The model developed in the study can be incorporated for the improvement of the intersection by studying other traffic flow characteristics.
Evaluation of factors that causes unsustainable overflow in Lagos metropolitan of Nigeria (EN47)
Imisioluseyi Akinyede - Cape Peninsula University of Technology South Africa
A sustainable environment is on agenda around the world, including planning for an effective way of waste disposal, design for the efficient drainage system and comfortable environment. Nevertheless, unsustainable overflow in cities of developing nations is a challenge; this trial is pivoted on physical environment and measurement management. In addition, unsustainable living by the habitat of these cities and the influence of the environmental inspectors create a gap for the research study. Consequently, necessitate the major reason to evaluate factors that cause unsustainable overflowing in Lagos metropolitan of Nigeria. The methodology employed for the investigation of factors that causes unsustainable overflowing in the city of Lagos is sequential mixed method approach; quantitative questionnaires were administered to the civil engineers, architects, environmental inspectors and waste management stakeholders in Lagos-state. The qualitative interview was used to validate findings obtained from analysis of quantitative data, thereafter; an interview was conducted among selected environmental inspectors from level 12 above, local government engineers and managers of the waste management board to achieve the aim and objective of the research study. The factors that impact unsustainable overflowing are as follows; public enlightenment on waste disposal system, establishment of sustainable waste disposal training for public sectors, Inadequate consideration of sea level for project development, establishment of sustainable waste disposal policy, and adequate implementation of these factors by all stakeholders will enhance physical environment management, consequently improve the operation performance of environmental inspectors and reduce diseases triggered by unsustainable overflow and stagnation of erosion water.
Keyword; Evaluation, Environment, Metropolitan, Overflow and Unsustainable
Seasonal and temporal variations of chloride level in riverine environment (EN50)
Qianru Situ - University of Calgary, Musa Akther - University of Calgary, Jianxun He - University of Calgary
Chloride is one of essential elements for the health of all organisms, humans included; it however has detrimental impacts on ecosystem at elevated level. While chloride is a naturally occurring element, it also originates from anthropogenic sources, for example, treated wastewater effluent. Thus chloride level in water bodies can be affected by both natural factors (e.g., hydro-meteorological variables) and anthropogenic factors (e.g., various anthropogenic activities).
The use of road salts to improve the driving condition of roadways in winters is a common practice across Canada. Canada, as one top producers of salt, applies approximately 45% of salts for road deicing. The impact of the application of road salts on riverine chloride level has been well acknowledged. The impact can be standing out in snow-melt season and also over a prolonged period. Besides, the dependency of chloride level on flow has often been seen in rivers regardless of the impact of anthropogenic activities. Therefore, this study aimed to investigate the seasonal and temporal variations of chloride and to understand the causes of variations through analyzing available data statistically. The data including chloride concentration, the use of road salts, and river flow were collected.
In general, seasonal variation of chloride was observed and chloride concentration was negatively correlated with flow at the majority of stations. Its seasonal variation pattern and dependency on flow however appeared to be different between large and small rivers in a certain degree. Before 2004, significant upward trend of chloride was detected at many stations; while after 2004, no trend and downward trend were detected at many stations, especially in Ontario. The increasing chloride concentrations in rivers were qualitatively linked to the increase of the use of road salts in general, although the Code of Practice for the Environmental Management of Road Salts issued in 2004 appeared to help in reducing the increase trend of chloride level. The upward trend of chloride concentration has often been conceptually linked to the increase of anthropogenic activities. This study also applied the approach of locally weighted scatterplot smoothing (LOWESS) to derive the flow-adjusted chloride concentration. The causes of the trend in chloride due to flow and other factors (except flow) were investigated. The analysis results demonstrated that the temporal trend observed in riverine chloride could be primarily ascribed to the temporal variation of either flow, or anthropogenic activities, or their combination.
Leaching behavior of nutrients and metals of green roofs: Laboratory and field studies (EN49)
Musa Akther - University of Calgary, Jianxun He - University of Calgary, Angus Chu - University of Calgary, Bert van Duin - City of Calgary Water Resources
In the stormwater management context, the green roof has been a practical low impact development technology for attenuating the detrimental effects of urbanization. In its implementation, especially at the initial stage, nutrient and metal leaching are common and problematic. However, to date research in this aspect is limited. Research on questions, such as what factors primarily govern leaching from green roofs and whether laboratory- and full-scale green roofs would behave similarly, would enhance the design and application of green roofs.
To answer the above questions, laboratory experiments were conducted and a full-scale green roof along with a nearby conventional roof situated on the Municipal Building of the City of Calgary was monitored from 2015-2017. In the laboratory experimental study, nine laboratory cells, which were constructed using three types of commercially available growing media (ZinCoblend-SI, Eagle Lake media blend, and SOPRAFLOR I) at three depths (100, 150, and 200 mm). Simulated events (2-, 5- and 10-year) were applied to the cells; while the full-scale green roof (150 mm ZinCoblensd-SI) and the conventional roof were monitored in natural events. The water samples collected from roof cells and field were analyzed for nutrients (nitrate, ammonia, total nitrogen, orthophosphate, total phosphorus) and metals (Zn, Cu, Pb). Statistical approaches were adopted to investigate the leaching behavior of green roof cells with different growing media at different depths in addition to the possibility to translate laboratory knowledge to field.
The laboratory observations showed that nutrient and metal concentrations of outflow in general decrease with the cumulative inflow volume at the early operation stage of green roof cells when they behaved as the source of pollution; however, the leaching response to the cumulative inflow appeared to be different in different types of media and/or media depths. Similarly, the full-scale green roof has also behaved as the source of pollution (using the conventional roof as the reference) since it commenced operation in July of 2015. The concentrations of several nutrients and metals of outflow from the full-scale green roof were observed to decrease with time in general. These results suggest that attention should be paid to reduce nutrients leaching when designing green roofs to ensure more efficient stormwater management. To well predict the leaching behavior of green roofs in the field, further investigation on the effect of other factors such as temperature and their age is recommended.
Use of ANSYS for calculating ground bearing pressure under crawler crane tracks and pad load under the outriggers of hydraulic cranes. (GC30)
Ghulam Muhammad Ali - University of Alberta, Mohamed Al-Hussein - University of Alberta, Ahmed Bouferguene - University of Alberta, Joe Kosa - NCSG Crane and Heavy Haul Services
Maintenance and assembly of modular projects in the heavy construction industry relies predominantly on high capacity mobile cranes of which hydraulic and crawler cranes are the most widely used. Because of the weight of the modules that are to be lifted, which nowadays can be expressed in hundreds of tons, ensuring proper ground integrity under the lifting equipment is paramount since its failure can result in dire consequences for the workers and the project. As a result, the first order of business, before selecting a crane for a specific project, is to evaluate the expected pressure under the tracks (or the outriggers) in order to determine the necessary ground treatments in order to make the lifting operation safe. In contrast to the traditional approach, where equations from statics are used to determine the pressure at specific points, this contribution adopts a continuous perspective by using finite elements modelling (FEM). In this context, the pressure analysis yields a continuous map that can provide a more accurate view of the load distribution. Furthermore, the output of the proposed finite elements based approach will be used (in this work) as an alternate source of data that can be compared to the results of the traditional statics method (widely used by crane companies).
Residual Drift Based Seismic Design of Shape Memory Alloy Reinforced Concrete Bridge Pier (DM43)
Shahria Alam - University of British Columbia, Muntasir Billah - Parsons
Experience from past earthquakes and laboratory experiments suggest that structures designed according to current seismic standards are susceptible to residual deformation even during a design level earthquake. With the advancement in performance based seismic design, residual deformation has received very little attention in design codes and guidelines. Under seismic excitation, residual deformation is a direct outcome of nonlinear structural response. Researchers have developed several recentering structural systems to reduce the residual deformation during a seismic event. This paper proposes a residual drift-based design methodology for Shape Memory Alloy reinforced concrete (SMA-RC) bridge piers, which consists of defining the performance objectives, developing performance based damage states and formulating a performance based design guideline considering residual drift. The procedure anticipates the allowable residual drift based on target performance level, calculates the maximum allowable drift, and ensures that those deformation demands remain below the allowable residual and maximum drift.
A Smart Self-Centering Bracing System for Earthquake Resisting Structures (DM27)
Anas Issa - University of British Columbia, Shahria Alam - University of British Columbia, A.B.M. Rafiqul Haque - Parsons Corporation
Concentrically Braced Frames (CBFs) have been developed and used to resist lateral forces over many years. Buckling, however, is a major concern for CBFs where they lose their strength and stiffness when subjected to severe earthquakes. Additionally, buildings with traditional CBFs structural systems experience large residual deformation after an earthquake, and often lose their serviceability and need to be demolished incurring huge economic losses. In order to resolve this issue, various smart structural systems have been developed by many researchers. One such system is the novel Piston Based Self-Centering (PBSC) bracing system. This study investigates the cyclic performance of this bracing system experimentally and numerically to predict its load-deformation response during seismic events. This newly developed bracing system employs Nickel Titanium (NiTinol) based Shape Memory Alloy (SMA) bars inside a sleeve-piston assembly for its self-centering mechanism. During cyclic tension-compression loading, the bars are pulled from opposite directions in order to avoid compressive loading on the bars. The energy dissipation is achieved through nonlinear load deformation hysteresis. Furthermore, the PBSC bracing system is designed to be fully buckling restrained. The developed system is easy to fabricate and low cost compared to the available systems. A prototype model is fabricated and tested under quasi-static loading protocol where experimental and numerical results showed excellent agreement. Furthermore, the system exhibits flag shaped force deformation hysteresis. A braced frame equipped with the PBSC system is designed and its seismic performance is evaluated in terms of inter-story drift responses.
Keywords: Bracing, Seismic resistance, Piston, Quasi-static, Hysteresis, Shape Memory Alloy
Experimental and Numerical Study of Thermal Buoyant Offset Jet Discharged into Stagnant Water (EN1)
Hassan Alfaifi - University of Ottawa, Abdolmajid Mohammadian - University of Ottawa
The aim of this paper is to study the behavior of the offset thermal jet in the mixing zone for the effluent of the industrial outfalls (e.g. desalination plants) on the near-field, experimentally and numerically. Several experiments of the thermal buoyant offset jet discharged horizontally into stagnant ambient water are conducted. The Particle Image Velocimetry (PIV) method is used to measure the time-history of the velocity distribution in the near-field mixing zone. The characteristics of the jet flow with different densimetric Froude numbers (Fd) compared with numerical results are presented in this study. Two different densimetric Froude numbers (Fd) (10 and 20) and difference density (Δρ) (5 and 10) are used. Three Reynolds-averaged Navier-Stokes (RANS) turbulence models; standard k-ε, realizable k-ε and buoyancy-modified k-ε models are applied in this study. The comparison between laboratory and numerical results for jet trajectory as well as with existing experimental and numerical data are presented. In general, a good agreement is observed between all numerical and experimental cases examined here, for both Froude numbers, where the realizable k-ε was shown to be the best among others.
Correlation Between Different Factors Controlling Shrinkage Behavior of Geopolymer Mortar (MA24)
Ahmad Alhamdan - Concordia University, Ahmed Soliman - Concordia University
Cement industry produces large amounts of carbon dioxide causing many environmental problems including global warming and air quality deterioration. As an alternative to cement, many studies have been conducted on alkali-activated materials (so-called geopolymers). Geopolymers showed similar or better mechanical and durability performance compared to that of cement-based materials. However, shrinkage behaviour of geopolymer materials is still one of the main problems that impede its in-situ applications. Hence, this study focuses on investigating the interrelationship between different factors that control shrinkage behaviour of geopolymer materials. These factors include supplementary cementitious material type, activator type and concentration, and curing temperatures. The setting time, workability, compressive strength, autogenous and drying shrinkage of alkali-activated mortars (AAMs) were evaluated. Results showed that the effect of activator type and concentration on the shrinkage behaviour differs according to the curing temperature. Moreover, the relationship between autogenous and drying shrinkage was significantly affected by the type of supplementary cementitious material used. Generally, the curing temperature is the most controlling factor for shrinkage behaviour of AAMs tested and also showed a strong influence on the effects of other factors.
Effect of Shrinkage Reducing Admixtures on Shrinkage Behavior of Geopolymer Mortar (MA25)
Ahmad Alhamdan - Concordia University, Ahmed Soliman - Concordia University
Alkali-activated binder (so-called geopolymer) is an eco-friendly binder alternative for cement. It is characterized by a very low carbon footprint. However, shrinkage of geopolymer materials is still one of the main challenges that impede its in-situ applications. The purpose of this study is to investigate the shrinkage behaviour of geopolymer mortars activated with different activator concentrations and incorporating different dosages of shrinkage reducing admixture (SRA). Moreover, it explores the influence of SRA on the correlation between shrinkage behaviour and different factors including the concentration of activator and curing temperature. Geopolymer mortars were prepared using the conventional two-part alkali activation mechanism. Specimens were exposed to different curing conditions. A series of tests including setting time, flowability, drying shrinkage, and compressive strength of geopolymer mortar were conducted on mixtures with and without SRA. Regardless of the activator dosage, results showed that similar to cement-based materials, SRA was effective in reducing the shrinkage strains experienced by geopolymer mortars. However, the compressive strength was decreased. Furthermore, SRA effectiveness increased with higher curing temperatures and activator concentrations.
The Influence of Fibre Volume Fractions on the Flexural Strength of FRP Reinforced Stringers (ST85)
Ahmed Alshurafa - University of Windsor, Hanan Alhayek - University of Manitoba
The Influence of Fibre Volume Fractions on the Flexural Strength of FRP Reinforced Stringers
Mr. Alshurafa A.1, Dr. Alhayek H.2
1University of Windsor, Civil and Environmental Engineering, Windsor, ON, N9B 3P4, Canada
2University of Manitoba, Civil Engineering Department, Winnipeg, MB, R3T 2N2, Canada
A research has been conducted to study the effects of fibre volume ratios on the strength and on the stiffness of fiber-reinforced plastic (FRP) stringers. Since there is no literature was found to evaluate the effects of fibre volume fractions on the structural behavior of the FRP stringers, this paper is intended to fill in this gap. The paper employed a finite element model to theoretically evaluate the structural behavior of the reinforced FRP Douglas fir Timber beams. A total of four FRP reinforced stringers were analyzed under three points bending. The beams were 4.8 m long, each had a cross-section of 150 mm wide by 330 mm deep. Several unidirectional fibre-glass materials were mixed with Epoxy West System of 105 resin and 206 hardeners to manufacture various plates with various contents of fibre. The material properties used in the ANSYS program were obtained from ASTM FRP coupons testing. The results showed that the higher fibre volume ratio used in the manufactured FRP plates, the higher the strength and the stiffness of beam. This study confirms that FRP can be used as an effective and viable solution for strengthening and stiffening beams, without adding any substantial weight to the structures.
Field Inspection and Classification of Pavement Distresses of St. John's City in Newfoundland Canada (MA43)
A. Ali - Memorial University of Newfoundland, Kamal Hossain - Memorial University of Newfoundland, Heena Dhasmana - University of Illinois at Urbana-Champaign, Md Safiuddin - Ryerson University, Carlos Bazan - Memorial University of Newfoundland, Amgad Hussein - Memorial University of Newfoundland
The City of St. John’s (Newfoundland and Labrador, Canada) has a unique climate, with excessive precipitation year-round, moderate summers and extreme winters. The pavement foundation (subgrade) in this region consists mainly of strong metamorphic rocks. As the city is located on an island and has a small population size, roads of this city experience very low volume of heavy traffic. Despite having less traffic and strong foundation, most of the roads in St. John’s suffer from serious structural and functional distresses. The distresses include but are not limited to deformation (structural, abrasion), moisture damages (pothole, ravelling), fatigue cracking (top down, bottom up), thermal cracking (longitudinal, transverse) etc. These distresses eventually lead to longer travel times, higher vehicular and pedestrian crashes and fatalities, excessive fuel consumption due to additional maneuvering actions as a result of poor road conditions, high CO2 emissions and a sub-standard ride quality. To address these issues, a comprehensive understanding of these distresses under local conditions is necessary. As an intial effort, a small-scale field survey was conducted and the distresses were classified and ranked based on type and severity. In addition, summary of each distress mechanism has been presented, followed by some recommendations to mitigate and address these distresses in this region. It is expected that this study will not only contribute in enhancing the pavement service-life by developing an improved asphalt mixture design in future but also reduce deleterious emissions and improve traffic safety.
Experimental and empirical study of basalt fiber reinforced concrete (MA39)
Mehran Khan - Department of Civil Engineering, Dalian University of Technology, Dalian, Cao Mingli - Department of Civil Engineering, Dalian University of Technology, Majid Ali - Department of Civil Engineering, Capital University of Science and Technology
Basalt fiber reinforced concrete (BFRC) can be used for structural applications like buildings and bridges. The BFRC can be developed with the addition of CaCO3 whisker due to their improved mechanical properties. The experimental investigation on BFRC is going on but at the same time the empirical formulation is also of great concern. Therefore, the experimental and empirical formulation needs to be studied at the same time. In this work, the impact of different basalt fiber lengths on flexural energy absorption of basalt fiber reinforced concrete (BFRC) will be investigated. In addition to this, the empirical equation modeling for the calculation of flexural strength will also be discussed. The mix design ratio of HFRC is 1:2:1.5 (cement: sand: aggregate) with a water-cement ratio of 0.50. The basalt fiber and CaCO3 whisker content of 5%, by cement mass, are added. To prepare BFRC1, BFRC2 and BFRC3, different basalt fiber length of 12 mm, 25 mm and 37 mm, respectively, are added. For determination of flexural strength, pre-crack/post-crack energy absorption and toughness indices, beam of size 100 mm width, 100 mm depth and 400 mm length are cast and will be tested under flexural load as per ASTM standard. Increase in flexural energy absorption of BFRC is observed with increasing length of basalt fiber. Further study on optimization of basalt fiber length and content for mechanical properties is suggested.
Utilization of FRC Tension Zone for Reinforcement Reduction in Slabs- A Simplified Approach (MA22)
Tasaddaq Hussain - Capital University of Science & Technology, Majid Ali - Department of Civil Engineering, Capital University of Science and Technology
The use of Steel Fiber Reinforced Concrete (SFRC) as a structural material is increasing day by day. One of the main advantages of fiber-reinforced-concrete is that the cracked-concrete below neutral axis in a cross-section can be considered up to some extent. Complicated equations exist for taking into account the tension zone of FRC. In this work, a simplified equation for estimating the tensile force of SFRC is proposed to calculate the nominal moment capacity of slabs. Flexural strengths of plain concrete (PC) and SFRC are investigated to study the effect of steel fibers on reinforcement reduction in slabs. Modulus of rupture (MoR), corresponding deflection, energy absorption (E), toughness index (TI) and density are determined experimentally. The mix design of 1:3:2:0.7 (cement: sand: aggregate: water) is used for preparing PC. Steel fibers with a fiber content of 5%, by mass of cement, and 5 cm length are used for preparing SFRC. Prisms of standard size are cast for both PC and SFRC and tested as per ASTM standards. It is found that MoR, E and TI of SFRC are increased by 43%, 667% and 423%, respectively, compared to that of PC. Rebars in SFRC are reduced up to 25% resulting in reduction of 12% material cost of slab.
Case Study: Flaws of concrete roads in Pakistan - Possible reasons and remedial measures (TR47)
Mehran Sudheer - Capital University of Science & Technology, Muhammad Usman Farooqi - Capital University of Science and Technology, Majid Ali - Department of Civil Engineering, Capital University of Science and Technology
Concrete pavements are durable structures as these are having more strength compared to flexible pavements. Their demand in the developing countries has been increased to cater the heavily loaded traffic volume. But it is observed that rigid pavements are also prone to number of distresses. These problems are either due to improper construction practices and materials or deviation from design standards during the construction work. In this study, the flaws in the concrete pavements of Pakistan are identified with the help of site visits and are associated with the data acquired from the local highway authority. The distresses in rigid pavements are compared for newly constructed, six months old, five years old and ten years old concrete pavements. The possible governing reasons for these flaws are rationally analyzed and reported. Accordingly, the crunch remedial measures are extracted through this exercise, keeping in mind economical and fast repairs, long service durable life and sustainable solutions. Recommendations are made for the rehabilitation of the surveyed concrete roads. The guidelines are also applicable for other existing concrete roads with similar kinds of problems in other developing countries. In addition, an emphasis is made to recommend changes in construction practices of new concrete roads so as to avoid identified types of flaws.
Effect of sisal fibrous mortar in improving out of-plane resistance and damping ratio of masonry column (ST119)
Furqan Qamar - University of Warwick, Majid Ali - Department of Civil Engineering, Capital University of Science and Technology
Masonry construction forms a large part of the structures throughout the world. The ancient and creative inheritance as well as the housing structures in the old town and countryside are usually made of masonry. It is well recognized that the existence of tiny discrete fibres in a cementitious product can result in a considerable development in the mechanical behavior of the composite. In this study, sisal fibres are used within mortar of masonry column and experimentally evaluated for stiffness, strength, ductility, energy absorption, toughness, and damping ratio. The plain mortar columns are considered as reference. All columns tested consist of single block width and were 1.5m high. The block was made of cement stabilized soil. Mortar consists of 1:3 cement sand composite. For fibrous mortar, 2% (by mass of cement) of sisal fibres are added. A total of four columns, i.e. two in each case, are investigated. The behaviors of fibrous and non –fibrous mortar columns were very similar and failure of the columns occurred between 80-90N with an average displacement of 14-16mm. It was found that there was 10% increase in the displacement for fibrous mortar column, resulting in enhanced ductility. An increase of 8% in failure load of fibrous mortar column was also observed when compared with to that of non-fibrous mortar column. The increase in damping ratio was noted for the fibrous mortar columns, which is an important parameter in resisting the seismic loading.
Analysis of the Effect of Warmest Climate Change Scenario in Jamuna River Floodplain Using HEC-RAS 2D Model (GC87)
Ummay Sumaiya - Military Institute of Science and Technology, Mohammad Mostafa Ali - Bangladesh University of Engineering and Technology
Bangladesh is a deltaic country located at the lower part of the basins of the three mighty rivers – the Ganges, the Brahmaputra and the Meghna. Jamuna is the main distributary of Brahmaputra river and is the second largest river in Bangladesh carrying an enormous volume of water through the country. Besides, the geographical position of Bangladesh made her more vulnerable to flood. Furthermore, for global climate change, catastrophic floods in Bangladesh will appear more frequently with increasing severity. Therefore, a synthetical approach has been made to understand the effect of the warmest climate change scenario (RCP 8.5) on the flood parameters, e.g., flood inundation depth, flood duration, flood arrival time, and flood recession time for the floodplain of Jamuna river. The analysis is done by using HEC-RAS 2D model for 2020s (2010-2039), 2050s (2040-2069), 2080s (2070-2099) and Base Year Flow (1981-2010). The study area has been chosen based on the flood inundated area of 1998’s flood, the highest flood occurred in Bangladesh. Bahadurabad station and Sirajganj station have been chosen as the upstream and downstream boundaries, respectively. The topographic data for the floodplain has been collected from US Geological Survey and the bathymetry data of 2011 has been used for the initial model geometry. A combined bathymetry and topographic DEM has been created by ArcGIS and used for further analysis in HEC-RAS 2D. The hydrodynamic calibration and validation have been done in Mathurapara and Kazipur stations respectively for the flood year of 2004 and 2005. Furthermore, Flood inundation maps generated from HEC-RAS 2D are compared with the observed flood maps of 2004 and 2005 from MODIS. After successful calibration and validation, flood inundation maps has been generated for the base year flow (1981-2010), 2020s, 2050s and 2080s. The simulation results shows that the flood characteristics will change due to warmest climate change scenario. The flood comes earliest in the floodplain in 2080s, earlier in 2050s and early in 2020s compared to the base year flow. The flood recedes first in 2080s, next in 2050s, then in 2020s compared to the base year flow. The depth inundation shows that flood depth will be highest for year 2080s, then 2050s and next 2020s compared to the base year flow. This analysis will be beneficial for local authorities, NGOs and planners to get a better idea about the characteristics of the flood in future for planning, agricultural production, and other important aspects.
Use of Waste Materials in Construction of Low-Cost Engineered Wood (MA15)
Sara Ali - American University in Cairo, Khaled Zahran - American University in Cairo, Mohamed Assal - American University in Cairo, Moustafa Sakkari - American University in Cairo, Omar Nasser - American University in Cairo, Seif El-din Diab - American University in Cairo, Mustafa Tageldin - American University in Cairo, Mohamed Darwish - The American University in Cairo, Khaled Nassar - American University in Cairo, Passant Youssef - American University in Cairo
The waste produced during sawing wood has been a source of pollution and hazards for years. The use of such waste together with different binders in the production of engineered wood products has been studied by researchers for the past three decades. The current study involves performing several mixes of involving these wastes together with a binder that is also an industrial waste. The mixtures were composed of different gradations with different proportions subjected to different pressures and temperatures during production. Standard strength tests are performed on the different mixtures produced under different conditions to determine the mix having the best properties and its most suitable production pressure and temperature. Finally, structural analysis and design of wall panels made of the chosen mix are performed.
Enhanced Model for Calculating the Required Lengths of Acceleration Lanes at Freeway Interchanges (TR32)
Essam Dabbour - Abu Dhabi University, Engy Hossam - Abu Dhabi University, Nour Ally - Abu Dhabi University, Ayah Elshennawy - Abu Dhabi University, Hiba Falaknaz - Abu Dhabi University
Many traffic collisions occur every year due to drivers improperly merging with mainline traffic streams near freeway interchange ramps. Many of those collisions occur due to inadequate lengths available for merging drivers to accelerate to the design speeds of the freeways they are merging with. Current US geometric design guide provides design tables to calculate the required lengths of those acceleration lanes that are based on research studies conducted in the 1950’s and 1960’s. The Canadian geometric design guide provides design domains for the required lengths of acceleration lanes that are based on those older editions of the US geometric design guide. Furthermore, the design domain provided by the Canadian geometric design guide for each speed is significantly large. For example, the recommended length of the acceleration lane that is required to accelerate from 60 km/h to 100 km/h is 140 m to 325 m. This paper provides an enhanced model for calculating the required lengths of acceleration lanes at freeway interchanges based on actual drivers’ behavior and vehicle mechanical characteristics. Acceleration profiles are established based on field data collected using Global Positioning System (GPS) data loggers that recorded the positions (latitudes, longitudes and altitudes) and the instantaneous speeds of different vehicle types piloted by different drivers at 1-s intervals. Design tables and different application examples are presented to help designers select the required length of an acceleration lane based on the design speed of the freeway and the entering or exit speed of the interchange ramp.
Shrinkage cracking in alkali-activated slag concrete: Mitigation techniques (MA72)
Wala'a Almakhadmeh - Concordia University, Ahmed Soliman - Concordia University
Despite the current knowledge about shrinkage of alkali-activated slag concrete and mitigation techniques, shrinkage is still one of the main problems that impedes its in-situ applications. It seems that there is a clear gap between the measured performance inside the lab and actual performance in-situ of alkali-activated materials. Shrinkage cracking can dramatically reduce the durability of any concrete member. Hence, a comprehensive understanding of the mechanism of the shrinkage phenomenon and effectiveness of different mitigation techniques are essential to prevent these damages in future. In this paper, an overview is given on the mechanism of shrinkage crack formation and the status of present technologies to avoid cracking. This would allow engineers to select the suitable mitigation technique for different applications
Review of Bridge Design Practice for Resilience to Water Loads, Scour, and Ice Action in a Changing Climate (GC155)
Enda Murphy - National Research Council of Canada, Vahid Pilechi - National Research Council of Canada, Paul Barrette - National Research Council of Canada, M. Naveed Khaliq - National Research Council of Canada, Husham Almansour - NRC Canada
In the context of design and retrofitting of transportation infrastructure for climate resilience, a review of historical and recent damage to bridges in Canada and internationally underlines the risks posed by water loads, scour and ice effects. More than 50% of bridge failures in North America are attributed to floods and hydraulic factors, including scour, debris impacts and ice effects. River ice is unique challenge for bridges in northern climates, with most Canadian rivers having seasonal ice cover. Estimates of annual average damages in Canada due to ice jams exceed $100 million.
The rising costs and damages associated with extreme weather events highlight the vulnerabilities of Canadian infrastructure to climate change. Potential changes in exposure to ice and flood (riverine, pluvial, and coastal) hazards pose a threat to the integrity and sustainability of transportation infrastructure, including bridges and overpasses.
The Canadian Highway Bridge Design Code contains provisions for evaluating water loads, scour and ice action for new bridges, and refers to the Transportation Association of Canada’s 2004 Guide to Bridge Hydraulics for design criteria and methods of analysis. However, there are no provisions for evaluating potential climate change impacts on these loads and effects.
The Government of Canada, through Infrastructure Canada, has recently launched the multi-year Climate Resilient Buildings and Core Public Infrastructure project, led by the National Research Council. A key objective of the project is to support outcomes that will enable the reduction of fatalities, infrastructure damage and economic losses from climate change and extreme weather events by developing new and improved tools and guidance for the design and protection of buildings and core public infrastructure.
A review of the current state of bridge design practice for evaluating, mitigating and adapting to water loads, scour, ice action and related climate change impacts was conducted. This included an appraisal of design codes, standards and guidelines from Australia, Canada, Europe, Japan, New Zealand, Russia, and the United States. The review identifies current gaps, emerging best practices, and initial recommendations for steps towards improving design guidance and the resilience of Canadian bridges and overpasses to water loads, scour, ice action and climate change.
Developing and Validating Regression Models to Predict 85th Percentile Operating Speeds for Roundabouts in Abu Dhabi, United Arab Emirates (TR34)
Essam Dabbour - Abu Dhabi University, Mohammad Almoarawi - Abu Dhabi University
Given the popularity of multi-lane roundabouts in the United Arab Emirates, it is necessary to develop models to predict the potential operating speed at a roundabout during its design stage to ensure that the expected operating speed and capacity of that roundabout will meet the design expectations. In this paper, regression models were developed to predict the 85th percentile operating speeds at multi-lane roundabouts in Abu Dhabi, the capital city of the United Arab Emirates. Three models were developed to predict the entering, circulating, and exiting speeds, respectively. The speeds are predicted based on hourly traffic volumes as well as the geometric characteristics of the roundabouts. The developed models were validated with data not used in calibration and they were found to be stable and robust. Based on the observations collected in this research, it was found that the operating speeds at most roundabouts in Abu Dhabi exceed those suggested by design guides, which might be attributed to the large radii used in Abu Dhabi roundabouts.
From top-down to bottom-up approaches to risk discovery: A paradigm shift in climate change impacts and adaptation studies related to the water sector (DM36)
Ousmane Seidou - University of Ottawa, Abdullah Alodah - University of Ottawa
Abstract: Healthy water resources are key to every nation’s wealth and well-being. Unfortunately, stressors such as climate change, land-use shifts, and increased water consumption are threatening water availability and access worldwide. The pressure on water resources is projected to increase dramatically in the future and turn into a global crisis unless bold actions are taken. Researchers and practitioners are therefore under great pressure to develop methodologies and tools that can streamline projected changes into adaptation decisions. The vast majority of climate change adaptation studies use a top-down approach, which essentially consists of using of a limited set of climate change scenarios to discover future risks. However, recent research has identified critical limitations to that approach; for instance, even when multi-model multi-scenario projections are used, not all possible future conditions are covered and therefore plausible risks may be overlooked. There is also no established way to evaluate the credibility of a given projection scenario, making it a challenge to include them in a decision or design framework. The bottom-up approach (which consists of identifying risky situations using stochastically generated climate states then use projections to evaluate their likelihood in the future) was recently put forward to address the limitations of the top-down approach, but several issues remain unaddressed. This paper proposes a methodology that allows the generation of a large number of climate change projections by combining the outputs of weather generators to the outputs of regional climate models, and associate a likelihood to each projection. The new set of projections provide a better coverage of the risk space, and can therefore facilitate the implementation of the bottom-up approach. Applications on the Upper Niger and Bani River Basins in West Africa, implementing 20 regional climate models (RCMs) with two emission scenarios (RCPs), is presented.
Incorporating Asset Value in Life Cycle Cost Analysis for Transportation Infrastructure Assets (TR9)
Zaid Alyami - University of Waterloo, Susan Tighe - CPATT - University of Waterloo
Life Cycle Cost Analysis (LCCA) refers to the direct financial costs associated with a project. LCCA evaluates competing alternatives by evaluating costs incurred along the project life cycle including initial construction costs, maintenance and rehabilitation costs to maintain functional condition along the service life. This process is widely applied because it can evaluate differences between design options such as pavement type and various feasible design cross sections. Agencies of all levels have used LCCA to evaluate new technologies, develop alternatives, and to provide defensible decisions for alternative financing and procurement of projects. LCCA is used by agencies to assist with long-term planning asset management plans and budget estimates. In essence, LCCA refers to the direct financial costs associated with a project, it evaluates competing alternatives by evaluating costs incurred along the project life cycle including initial construction costs, maintenance and rehabilitation costs to maintain functional condition along the service life. Agencies of all levels have used LCCA to evaluate new technologies, develop alternatives, and to provide defensible decisions for alternative financing and procurement of projects. In addition to maintenance and rehabilitation costs, agencies started to include other factors such as salvage value, user costs, and environmental costs in the LCCA. However, to date, the impact on asset value in LCCA is not considered. Incorporating asset value in LCCA as a means of evaluating the return on investment is imperative. Asset valuation is an essential component of effective asset management. It is an important method to demonstrate proper management of public assets and effective utilization of tax payers’ money. Asset valuation is used in standard reporting, depreciation schedules, auditor requirements and condition assessments. The paper presents a methodology to incorporate asset value as a component of LCCA. The proposed method is illustrated using data from the Ministry of Transportation (MTO) Pavement Management System (PMS2).
Novel Asset Management Framework for Road Maintenance (TR49)
Alireza Mohammadi - Concordia University, Charles Igwe - Concordia University, Luis E Amador-Jimenez - Concordia University, Fuzhan Nasiri - Concordia University
As assets begin to deteriorate either due to age or additional demands based on urbanization, it becomes imperative to renovate or replace them to ensure that they continue to deliver the level of service required by the end user. Asset management, therefore, becomes a very important consideration in the development of nations. However, there is another key factor worthy of consideration and this is based on the principles of lean construction. According to the lean construction paradigm, to increase value to the end user in any project, especially projects in urban areas where the effect of delays is more noticeable and profound due to the number of people requiring the use of these assets, waste must be eliminated or reduced to the barest minimum and doing this requires conformance to 5 major principles. Classical practices in the asset management domain; however, have not embraced the lean construction paradigm in road maintenance or rehabilitation plan. This paper suggests a framework to establish a formalized road management procedure with a focus on the principles of lean construction for avoiding non-value activities. To validate the proposed approach, a case study project is tested. The results of the case study revealed that by using the developed model, a 20% reduction in the project budget can be achieved while still ensuring that the required level of service is maintained. Based on this developed model, roads and other infrastructure decision-makers will be able to make better asset management plans that will ensure that project stakeholders including the end users get better value for their money and time.
Bench- and field-scale study of disposal of gypsum wallboard residuals (EN8)
Allison Mackie - Dalhousie University, Robert Anderson - Consulting, Graham Gagnon - Dalhousie University
Waste or residual gypsum wallboard has the potential to generate hydrogen sulphide (H2S) if disposed in a traditional landfill and most landfills do not accept wallboard for this reason. H2S is generated as a by-product of the respiration of sulphate-reducing bacteria (SRB). Gypsum wallboard contains both the sulphate (SO42-) and the organic material (i.e., paper backing) required for biological sulphate reduction by SRB to produce H2S, which is highly toxic in gaseous form. Landfills provide the anaerobic and moist environment required for SRB to thrive. The use of calcium- or iron-based materials, as well as household compost, as covers for landfills containing gypsum wallboard waste have been previously shown to be effective at adsorbing gaseous H2S emissions. This study compared five materials in mixtures with residual gypsum wallboard from a wallboard manufacturing plant at bench-scale for the mitigation of sulphide generation: cement kiln dust, N-Viro, agricultural lime, open hearth slag (OHS), and wood ash. These materials were mixed with gypsum wallboard residuals and placed in vertical columns to which synthetic, de-oxygenated rain water was added weekly. Leachate analysis from the columns indicated that wood ash and OHS were able to reduce leachate sulphide concentrations most significantly compared to control columns with gypsum residuals only. Wood ash was selected over OHS for field-scale testing due to its proximity to the wallboard plant. Field test plots were constructed on top of a wood ash/pulp mill biosolids landfill, comparing a 1:1 volumetric mixture of wood ash:wallboard residuals with wallboard residuals alone in two separate plots. Both plots were covered with a layer of pulp mill biosolids which effectively prevented any H2S gas emissions from the landfill. H2S gas was not detected in boreholes until the end of June and was lower in boreholes in the wood ash/wallboard plot compared to the control plot. However, boreholes in both field plots gave H2S readings greater than 600 ppm at the end of August, the hottest part of the season, after which readings decreased. Core sample pH and sulphate concentrations were consistent throughout the study period, while sulphide concentrations peaked in August as well. The results of this study show that co-disposal of gypsum wallboard with wood ash can help to reduce generation of H2S gas and that temperature was a key contributing factor controlling H2S gas generation.
Exploring Current Scoping Practices used in the Development of Transportation Infrastructure Projects (TR50)
Sharareh Kermanshachi - University of Texas at Arlington, Elnaz Safapour - University of Texas at Arlington, Stuart Anderson - Texas A&M University, Paul Goodrum - University of Colorado Boulder, Timothy R.B. Taylor - University of Kentucky, Hessam Sadatsafavi - Cornell University
Scoping studies has become an increasing popular approach to define a project and prepare it for execution. It assists to make a decision on how to efficiently proceed with the project. It is widely accepted that an inefficient scoping process is one of the major causes of project failure, cost overruns, and schedule delays in infrastructure projects. Therefore, the goal of the present study is to provide an overview of the scope definition, and also timing, tools, and resources used through scoping process by different State Transportation Agencies (STAs). The major challenges that each STA faces during the stated process in infrastructure projects are also presented. To fulfill the objectives of this study, several in-depth structured interviews with Subject Matter of Experts (SMEs) who worked in six transportation agencies were conducted and analyzed. The selected STAs for interviews were Minnesota Department of Transportation (MnDOT), Utah Department of Transportation (UDOT), Washington Department of Transportation (WSDOT), Kentucky Transportation Cabinet, Michigan Department of Transportation (MDOT), and Louisiana Department of Transportation Development (DOTD). After qualitative data analysis, the results revealed that due to different scoping definitions from agency to agency, the time frame and project scoping activities also vary. The results of scoping time demonstrated that project scoping generally starts with the identification of needs, and continues with the development of design alternatives, preliminary estimation of project costs, and identification of important milestones. It was concluded that the environmental personnel, design professionals, and maintenance personnel are more involved among construction personnel. Furthermore, the lack of time and qualified personnel to address the demand for feasibility analyses is determined as the major challenge to the scoping process. The findings of this research will assist owner entities and policy makers to structure the scoping process more appropriately in infrastructure projects.
Effects of Thermal Loading on a Composite Aluminium Deck-on-Steel Girder Bridge System (ST147)
Julien Leclerc - Université Laval, Charles-Darwin Annan - Université Laval, Victor Desjardins - Université Laval, Mario Fafard - Université Laval
This article discusses the use of an extruded aluminium hollow section as an alternate decking solution to the traditional concrete slab-on-steel girder system in highway bridge application. It is proposed to connect the aluminium deck panel to steel girders using ASTM F3125 / F3125M-15A galvanized steel M20 diameter bolts, grade A325, in a slip-critical connection. The goal is to develop a total composite action for a full flexural capacity of the composite beam. However, considering that the thermal expansion coefficient of aluminium is twice that of steel, differential movements between the aluminium deck and steel girders are possible due to temperature variations. This study uses the finite element method to examine the behaviour of the aluminium deck-steel girder assembly under the combination of thermal and mechanical loads at the serviceability limit state (SLS), as well as at the ultimate limit state (ULS). These loads are determined from specifications of the Canadian Highway Bridge Design Code (CAN / CSA S6-14). The results show that it is possible to develop full composite action between the aluminium deck panels and the supporting steel girders. The study also prescribes a recommendation to prevent slippage under thermal loads and to ensure that no slip takes place under service conditions.
A New Simple-Span Bridge Concept in Aluminium (ST148)
Jean-Baptiste Burgelin - Bouygues Travaux Publics, Michel Guillot - Université Laval, Charles-Darwin Annan - Université Laval, Mario Fafard - Université Laval, Victor Desjardins - Université Laval
In this paper, a new highway bridge concept made of an aluminium deck and supported on aluminium girders is developed as an alternative to the traditional bridge solutions, namely the slab-on-girder and wood-deck-on-girder bridges. The all-aluminium bridge system is conceived as a modular solution, to be fabricated under controlled environment and transported in two parts to be installed on-site. The modular solution ensures higher quality control and rapid on-site construction. The aluminium deck is made from extrusions, 200 mm deep and 370 mm width, which would be welded together using the friction stir welding (FSW) or by the traditional MIG (metal inert gas) welding technique. The aluminium girder is an inverted T-shape, and the top of its web is welded to the extrusion deck panels by means of a specially designed extrusion which eliminates the need for a top girder flange. The proposed design respects the requirements of the Canadian Highway Bridge Design Code (CAN / CSA S6-14). The aluminium deck is designed to be waterproof and requires minimal maintenance if care is taken to eliminate the risk of galvanic corrosion or accumulation of debris.
Application of Electrochemical Advanced Oxidation Processes (EAOPs) for Treatment of Concentrate from Psychrophilic Anaerobic Digester Units (EN35)
Mahbuboor Choudhury - Building, Civil and Environmental Engineering Department, Concordia University, Nawrin Anwar - Building, Civil and Environmental Engineering Department, Concordia University, Rajinikanth Rajagopal - Concordia University, Saifur Rahaman - Concordia University
This study applied electrochemical advanced oxidation processes (EAOPs) like electro-oxidation and electrocoagulation to treat the concentrate deriving from a psycrophilic anaerobic municipal organic solid waste digester units. The concentrate or effluent from anaerobic digestion units contains high concentrations of organics and suspended materials. As a result, such concentrate poses a formidable challenge for treatment in conventional wastewater treatment facilities. Recently, EAOPs have demonstrated a promising ability to reduce a variety of pollutants from wastewater efficiently. The EAOPs have the advantage of not requiring the addition of chemical reagents in the treatment process, and these can also be easily implemented by integration in an automated treatment system. Hence, a quick and efficient treatment for high strength wastewater is possible with EAOPs. This study used an open cylindrical glass electrolysis cell with Boron-Doped Diamond (BDD) as the anode and stainless steel as the cathode for the electrooxidation process. The electrolysis cell also contained an aluminum plate in bipolar arrangement for the electrocoagulation process. The electrooxidation and electrocoagulation process stabilized the organics, both dissolved and particulate, in the wastewater. Preliminary tests were conducted to assess the effects of different operational parameters (e.g., current density, treatment time) of the electrolytic cell on the overall treatment efficiency. Based on the preliminary results, combined electro-oxidation and electrocoagulation processes demonstrated great potential for treating the concentrate from anaerobic municipal organic solid waste digester units.
Improving the Customer Satisfaction with Automating the Facility Management System (GC33)
Asif Riaz - FWO, Zia Ud Din - ASU, Waqas Anwer - The University of Bradford
Engineering Service is a public organization dedicated to build and maintain facilities for Cantonments Pakistan. The mission of the Engineering Service is to provide a high-quality facilities management services that meet the requirements of its users efficiently and effectively. The facilities management services involve tasks related to receiving, responding, and tracking service requests initiated by facility users and providing customer service as required and expected. For efficient delivery of the service, a computer-based application of facility management system efficiently was developed and implemented replacing the old manual system. The application provided an administrative support function to receive service requests electronically, record and report routine and emergency requests about building or equipment faults and request for maintenance. The purpose of this research is to measure the effectiveness of the newly implemented facility management system to handle service requests and to obtain users’ satisfaction feedback using this system. This paper presents the application development process, implementation and surveys to measure the effectiveness of the system. A case study methodology was adopted, and survey data from operators, customers, and service request handlers (workers) were collected and analyzed. The result showed the total numbers of users’ complaints about facilities were handled efficiently as compared to the old system. This system is a valuable addition to improve the systematic management of users’ complaints and provide better services.
The Use of SUE Subsurface Utility Engineering data during the design of a pipeline relocation during a LRT Project (GC113)
OPHIR WAINER - T2 Utility Engineers, Lawrence Arcand - T2 Utility Engineers
ORAL AND PPT ORESENTATION ONLY!!!
ABSTRACTPublished in September 2011, the CSA S250 - Mapping Underground Utility Infrastructure will play a key role in the creation of more accurate and reliable as-built utility drawings and maps in Canada. CI/ASCE 38-02 - Standard Guidelines for the Collection and Depiction of Existing Subsurface Utility Data, which was published in 2003, has already been used extensively on infrastructure projects across Canada and the US. Together these two standards form a solid foundation to both map and records utility infrastructures.The location of existing utilities can play a key role in the design and implementation of infrastructure projects. These impacts need to be managed properly to avoid significant cost and schedule over runs. CI/ASCE 38-02 forms the basis for engineers to create accurate drawings of existing conditions for the project. The data provided upfront is a critical, however equally important is the generation of accurate, reliable maps and drawings of new utility infrastructure placed in the ground. Creation of these new records is the primary focus of the CSA S250 Standard. The paper will review the key highlights of the new CSA S250 standard including - standard symbology, Accuracy Levels, and data record keeping - and how it will improve our future knowledge of underground infrastructure. It will highlight the government and private agencies such as the Ontario Ministry of Transportation, City of Toronto, and Fortis Gas, currently using or looking to implement the use of the standard, and identify how the knowledge learned from that exercise can assist the principles of Proper planning flawless execution.Accurate reliable drawings of our underground utility infrastructure produced in accordance with these industry standards is a benefit to all stakeholders - Project Owners, Designers, Utilities, Regulators and Contractors. Further promotion for the use of these standards is the key, if we wish to raise the bar and move forward as an industry.
Transportation Association of Canada's new document - Guideline for the Coordination of Utility Relocation impact on Utility projects (GC114)
OPHIR WAINER - T2 Utility Engineers, Lawrence Arcand - T2 Utility Engineers, Steven Murphy - T2 Utility Engineers
The Transportation Association of Canada's (TAC) Public Utilities Management Sub-committee has published a new document - Guideline for the Coordination of Utility Relocations. The purpose of the guideline is to assist various ROW owners and Utility agencies to develop or enhance their utility coordination processes. For Utilities with infrastructure in a variety of areas it gives them a consistent process they can follow when working with any ROW owner. For ROW owners it allows them to learn from the best practices and procedures of different parties and implement a process that will be readily accepted and adopted by utility agencies.This presentation will review the key aspects of the new Guideline, highlighting the Objectives, Intended Audiances and some of the new developments being made. Major themes contained in the guideline such as the use of Utility Coordinators, and SUE mapping as per ASCE 38-02 will be reviewed.The audience will have an opportunity to ask questions about the new guideline and determine how it can best be incorporated into their community or business.
Effect of Input Excitation Characteristics on Extracting Modal Parameters Using Operational Modal Analysis (ST161)
Ethan MacLeod - University of New Brunswick, Kaveh Arjomandi - University of New Brunswick
In classical operational modal analysis (OMA) one of the central assumptions is that the excitation is a perfect Gaussian white noise. This assumption is difficult to validate and in many situations may not be correct. In practice, most excitations rarely are gaussian and often take on other distributions such a Rayleigh for wind loading or poorly defined distribution for sporadic loading generated from low traffic volumes. This paper investigates the influence these assumptions of excitation distribution have on the successful completion and accuracy of OMA methods. The efficiency of different OMA methods in handling non-gaussian excitation distributions will be determined using numerical investigations, comparing the theoretical results to values obtained performing OMA with the Frequency Domain Decomposition (FDD), Time Domain Poly Reference (TDPR) and Stochastic Subspace Identification methods (SSI).
Maintenance Prioritization of Bridge Structures (ST44)
Alec MacDonald - University of New Brunswick, Kaveh Arjomandi - University of New Brunswick
Bridges are aging and deteriorating faster than they are being maintained and replaced, and this is introducing a major problem for bridge authorities across the world. Several studies investigating the trends suggest that the severity is likely to become much worse. As such, there is a large backlog of work that needs to be completed to bring bridge networks up to a desired safety standard. To complicate the matter, the budgets allocated to this type of work are often sparse; and therefore, governing bodies are forced to have to choose how funds are spent. In tackling this problem, appropriate methods for determining the optimum maintenance sequence of bridges within a network must be employed. This has been investigated by several research groups, each proposing their own factors and approaches to be used for classifying the importance of a bridge within a network. This importance can be linked to maintenance optimization as the more important bridges should receive attention first. This paper reviews previously proposed solutions and discusses the similarities and limitations of each method. The current state of the art of maintenance prioritization methods are presented as a framework including a range of periodization factors with various resolution levels that can be optimized for specific networks.
Estimating Filtering Frequency for Vibration Serviceability Design Analysis of CLT Floors (ST123)
Ebenezer Ussher - University of New Brunswick, Kaveh Arjomandi - University of New Brunswick, Ian Smith - University of New Brunswick
Cross-laminated-timber (CLT) is the generic name for a class of prefabricated thick timber-plate products well suited to floor slab construction. The broad characteristic is CLT has interlocking bonded layers that self-reinforce it in orthogonal plate directions, making it well suited as an alternative to reinforced concrete (RC) slabs. Attractiveness of CLT is that it is relatively light and has similar load-bearing direction characteristics to RC. Like other relatively lightweight slabs, using CLT potentially increases proneness of floors to vibration serviceability performance problems. Discussion here addresses how CLT floor slabs vibrate due to surface impacts typical for normal building occupancy situations.
Building occupants are sensitive to aggregated motions that result from summed effects of contributions of all vibration modes excited by dynamic forces. Eurocode 5 which applies to vibration serviceability design of lumber joisted rectangular plan floors simply supported along all four edges recognizes this. It is also suggested by historical investigators that only lower order modes can contribute to motions building occupants can sense. Recent research at the University of New Brunswick (UNB) shows neither presumption is reliable for CLT slab floors constructed from one or more CLT plates. This manuscript discusses how modes with frequencies much higher than 40 Hz contribute to CLT floor motions caused by impacts representative of human footfalls, and implications for design.
Operational modal analysis (OMA) was conducted at the UNB on CLT floors with various construction features. Analyses of test data yielded mode shapes, and estimates of modal frequencies and damping. The broad finding from experiments is all extracted modal characteristics were sensitive to alteration of construction features, with clustering of modal frequencies being common. Finite element (FE) models were developed and calibrated using results from the experimental studies, with excellent correlation between FE model and OMA derived modal parameters. FE derived modal parameters are used to predict floor motions using time-history response FE analyses with impacts representative of human footfalls. Typical outputs from time-history response analyses include predictions of peak velocity (vpeak), peak acceleration (apeak), and root-mean-square acceleration (arms), as a function of the filtering modal frequency (FMF). In all cases the FMF at which responses plateaued was much greater than 40 Hz. The full manuscript will include detailed discussion of implications for engineering design practice.
Effect of Material Damping on the Dynamic Axial Response of Pile Foundations (ST14)
Campbell Bryden - University of New Brunswick, Kaveh Arjomandi - University of New Brunswick, Arun Valsangkar - University of New Brunswick
Novak’s elastic model is commonly used to predict the dynamic response of pile foundations. The primary source of energy dissipation within the idealized elastic model (i.e. damping) is of the geometric type as deformation waves propagate throughout the surrounding soil media. In addition to geometric damping, there is simultaneous internal material damping that occurs within the soil and pile materials, which may be incorporated as an out-of-phase compliment to the material stiffness values. Material damping is generally neglected from the analysis (or is assumed to be near-zero) when predicting the foundations dynamic response with Novak’s model. The present study demonstrates the potential consequences of neglecting material damping when performing dynamic analysis of pile foundations. This paper focuses on the axial vibration of an individual pile, and the influence of material damping on the dynamic response is investigated.
Framework for Design of Flood-Resilient Buildings in a Changing Climate (GC162)
Ahmed Attar - National Research Council, M. Naveed Khaliq - National Research Council of Canada, Zoubir Lounis - National Research Council, Marianne Armstrong - National Research Council of Canada
Increased frequency and costs of floods in Canada and changing climate conditions present many technical and economic challenges to the building and infrastructure design community. Lack of national standards for flood risk assessment and flood-resistant design of buildings are the major challenges identified by many Canadian stakeholders at a recent Workshop on Floods and Climate Change. To address these challenges, inputs from various levels of federal, provincial, territorial and municipal governments, national and international experts from engineering and climate science, insurance industry, agencies involved in flood mitigation, and the public sector are required to identify the knowledge gaps and the best possible path towards a harmonized framework for enhancing flood- and climate-resilience of buildings and infrastructure, based on a broad consensus and recommendations of all experts and stakeholders. This paper presents a harmonized framework for flood-resilient design of buildings in a changing climate. The framework considers: strategic engagement of federal, provincial, territorial and municipal stakeholders; improved interaction between code developers, structural engineers, and climate scientists; expertise of flood modellers and hydraulic engineers; and feedback from codes regulators, experts involved in codes implementation and code users. These engagements, interactions and feedbacks can be made possible through targeted national workshops.
Resilience Assessment of Water Networks against Seismic Hazard (DM25)
Ahmed Assad - Concordia University, Fuzhan Nasiri - Concordia University, Tarek Zayed - The Hong Kong Polytechnic University
Water Supply Networks (WSNs) are critical infrastructure systems that provide adequate amount of water to the public. Maintaining functionality of WSNs is desirable especially after hazard events to facilitate firefighting and rescue activities. Aging of WSNs increases their vulnerability and the likelihood of function interruption during and after disruptive events which are becoming more frequent and of more damaging consequences. There is a growing need to investigate the resilience of infrastructure systems to assess their ability to withstand a disruption and to recover rapidly after service interruption. Several models have been developed to consider resilience during the design of WSNs, however there is a setback regarding incorporation of resilience in repair strategies.
This study introduces a resilience-based asset management approach that aims at both decreasing the performance loss and enhancing recoverability of WSNs after a hazard event. Firstly, a resilience metric is suggested based on the physical condition of the pipelines in the WSN. Secondly, causal loop diagrams are established to capture the interactions among the parameters related to asset condition and deterioration, hazard intensity, performance loss, rehabilitation and restoring activities. Thirdly, stock and flow diagrams are formulated based on the afore-mentioned causal loop diagrams. In this step, relevant mathematical and logical relations between the system parameters are defined and several checks are performed to verify the developed model. Finally, the model is applied on a portion of Montreal WSN to simulate an earth quick that causes a 30% performance loss. A budget of one million dollar is found to be sufficient to recover half of this loss and increase the network resilience to 75% of its initial value. Half of the budget is allocated for replacement of broken pipes while the other half is evenly distributed among major and minor repairs. Various scenarios are then simulated to investigate the effect of changing the total budget on the overall network resilience before and after hazard.
The practical value of this study is signified by the tool, which can be used by the stakeholders to select the best management and mitigation strategies that increases the resilience absorptive and restorative capacities of their WSNs.
Performance Assessment for Water Networks (GC111)
Ahmed Assad - Concordia University, Tarek Zayed - The Hong Kong Polytechnic University
Water networks (WNs) are critical systems that secure the provision of adequate amount of water, that meets the certain quality guidelines, to the public. Water networks are deteriorating due to several factors which increases the number of breaks and leaks and affect water quality. Given, aging infrastructure and tight budgets, there is a rapidly increasing need for efficient rehabilitation programs to maintain the sustainable and cost-effective functionality of WNs. Developing such programs requires formulating a model that assesses the performance of water assets. While several studies in the literature have addressed the issue of performance assessment of WNs, few of them introduced a holistic approach that integrates the performance of the various components of the WN. Moreover, very limited efforts have investigated and included the criticality of such components. This paper introduces a novel model for assessing the overall performance of water networks based on criticality and reliability theory. Water network is first divided into smaller subnetworks. Each sub-network consists of several segments that are connected to each other. Segments are then broken down to its components; pipes, valves, and hydrants.
Previous number of failures of each component is used to estimate the component failure rate along with its reliability. Water pipelines are clustered into homogenous groups based on their characteristics. Weibull Probability Distributions are utilized to model the time between failures, censored data, and thus develop the deterioration curves of water pipes. Subsequently, the criticality of water pipelines is elicited to serve as a prioritizing tool that asserts more weight of importance on the pipes of significant social, environmental and economic consequence of failure. This study uses Fuzzy Analytical Network Process (FANP) for the first time to obtain the relative weights of the criticality factors and to hence the pipeline criticality. This technique accounts for both the interdependency between criteria factors as well as the inherited uncertainties during data collection. Multi Attribute Utility Theory (MAUT) is then adopted to calculate the performance of each segments. According to how these segments are connected, reliability theory is finally employed to assess the performance of water networks.
All the developed models are then integrated within one automated tool using Excel-Matlab® that facilitates the computation procedure. The in-depth evaluating of WN performance that can be derived using this approach will assist utility managers to accurately construct comprehensive maintenance and rehabilitation programs for the components, segments and theentire network.
Assessment of Canadian Floodplain Mapping and Supporting Datasets for Buildings and Infrastructure Design Codes and Standards (GC158)
M. Naveed Khaliq - National Research Council of Canada, Ahmed Attar - National Research Council, Enda Murphy - National Research Council of Canada, Ivana Vouk - National Research Council, Steffanie Piche - University of Ottawa
The Canadian Government, through Infrastructure Canada, has recently initiated the Climate Resilient Buildings and Core Public Infrastructure (CRB-CPI) project, led by the National Research Council of Canada. A key objective of the project is to update codes and standards and develop new guidelines to reflect the impact of climate change on the design (rehabilitation) of new (existing) buildings and CPI in order to enhance their resilience against extreme weather and climate change. To support this initiative, an assessment of Canadian floodplain mapping and supporting datasets was undertaken. This included a review of hydrologic and hydraulic techniques, and federal/provincial/territorial/local government initiatives to modernize floodplain maps from the technological, climate change and accessibility viewpoints. Some of the key points explored during the review included: the best ways of utilizing existing floodplain maps, which were originally developed to inform land use planning and development bylaws, to support the development of new codes and standards; the degree to which climate change has been incorporated in floodplain maps; and the status, availability and quality of available datasets to support quantification of flood loads for the design of buildings and CPI. This paper focuses on the findings of the assessment and the suggested path forward to develop structural design provisions for flood loads that can be implemented in the National Building Code as well as guidelines for addressing flood- and climate-resilience of existing buildings and infrastructure. This includes consideration for buildings of varying importance and with different functional requirements in response to flooding, e.g. residential, industrial, lifeline and post-disaster buildings and places of refuge/shelters.
Bond Behaviour of Externally Bonded Fiber Reinforced Polymer to Concrete under Static Loads (ST15)
Emmanuella Oluwatoyin Atunbi - University of New Brunswick, Alan Lloyd - University of New Brunswick, Peter Bischoff - Dept. of Civil Engineering, University of New Brunswick
Fiber reinforced polymer (FRP) has become widely used in the strengthening and rehabilitation of reinforced concrete structures. They are light in weight, non-corrosive and easy to install. Although many studies have been carried out to determine the behaviour of FRP strengthened reinforced concrete members, there is still a setback in its application because of many economical and design related issues. One of these issues is the need to fully understand the bond characteristics of the FRP-to-concrete interface. FRP strengthened reinforced concrete structures exhibit brittle failure and often debond prematurely before they utilize their ultimate capacity. This debonding failure is caused by the interfacial stress concentrations in the FRP-to-concrete interface. Previous studies on the bond behaviour of FRP strengthened structures under static loads involved the use of varying test setups and conventional instrumentation (strain gauges) that provide limited data to work with. Different researchers have also adopted varying specimen properties and parameters to develop models used for computing the bond characteristics of FRP reinforced concrete structures. Effective bond length of FRP is known to be an important parameter that influences the bond strength of FRP-to-concrete. This paper presents the results of an experimental program to investigate the effect of bond length on the bond behaviour of FRP-to-concrete interface under static loads. Twelve specimens consisting of a pair of prisms joined together by carbon fiber reinforced polymer (CFRP) sheets of varying length bonded on opposite sides of the specimen were tested to failure at the same loading rate. A non-conventional Digital Image Correlation (DIC) technique was used to measure strain distribution and corresponding deformation of the specimen as opposed to the use of strain gauges. The DIC measurements allowed for proper monitoring of the progression of failure and how shear lag affected the distribution of stresses along the specimen. Effective bond length values obtained from this study were compared with values computed from previous models suggested by other researchers. It was observed that there is a large deviation in the theoretical values in relation to the experimental values obtained.
Construction Experience Analysis of using CEMATRIX Lightweight Cellular Concrete as a Subbase material (GC26)
Sergey Averyanov - University of Waterloo, Frank Mi-Way Ni - CPATT - Waterloo University, Susan Tighe - CPATT - University of Waterloo, Eskedil Melese - University of Waterloo
Lightweight Cellular Concrete or LCC, also sometimes known as "foamed concrete" or "aerated concrete" is a useful construction material with many applications. LCC has some advantages such as sustainability, light weight, excellent thermal properties, freeze-thaw resistance, good flowability, cost-effectiveness. Due to its properties, it is a good material choice for contractors and transportation ministries to use in different applications in all weather conditions. It also satisfies construction requirements in poor soil areas – it is a good base for the pavement over weak soils because this material can reduce the effective stress on the underlying soil. The objective of this paper is to study and analyze the performance of the pavement sections with the LCC subbase in comparison with the regular pavement sections on the same roads. Three road sections that had been constructed with lightweight cellular concrete as a subbase were evaluated through pavement condition survey following ASTM D6433. It has shown that three sections were in good condition, without severe distresses. Preliminary failure criteria analysis was conducted using Weslea software. It has been found that using lightweight cellular concrete as a subbase has the greater allowable number of load repetitions for fatigue cracking and rutting than using granular material. This indicates that lightweight cellular concrete could be considered as an alternative pavement subbase material.
Characterization of Lightweight Cellular Concrete (MA16)
Frank Mi-Way Ni - CPATT - Waterloo University, Sergey Averyanov - University of Waterloo, Eskedil Melese - University of Waterloo, Susan Tighe - CPATT - University of Waterloo
Lightweight cellular concrete (LCC) is an alternative construction material with growing applications over the past three decades. It is mainly composed of hydraulic cement, water, and pre-formed foam. Its lightweight, ease of placement, and insulating property make it a suitable material for structural backfill, utility insulation, and road construction. Being an innovative material with diverse potential applications in the construction industry, it is worth knowing typical engineering characteristics of this material.
So far, various laboratory tests were conducted on LCCs at different Canadian laboratories. These include tests for resilient modulus, elasticity modulus, shear strength, tensile strength, hydraulic conductivity, thermal conductivity, and freeze-thaw resistance. The laboratory tests were conducted on LCCs with densities ranging from 400 kg/m3 to 600 kg/m3. These are typical densities of the LCCs that have been so far used in Canada for different applications. According to the test results, the resilient modulus and modulus of elasticity of the LCC vary over the ranges of 0.12 – 0.35 MPa and 850 MPa – 1,100 Mpa respectively, while the Poisson’s ratio range is 0.19 – 0.26. The freeze-thaw test results, on the other hand, indicates the relative dynamic modulus of the LCCs exceeds 80% after 350 freeze-thaw cycles. These show that LCC has good resistance to freeze-thaw even though their stiffness is low compared to chemically stabilized pavement materials.
In this paper, the mechanical and thermal properties of the lightweight cellular concrete that have been determined in various Canadian laboratories using standard and non-standard test methods will be compiled and presented. Besides, comparison of the test results with the results of similar tests that have been performed outside Canada will be incorporated and analyzed.
The City of Calgary 12 Street Bridge Prefabricated Deck Panels (ST46)
Azita Azarnejad - CH2M HILL, Nathan Murdoch - CH2M (now Jacobs), Ahmed Elmetwally - CH2M, Paul White - LafargeHolcim, Katherine Hikita - City of Calgary Transportation Infrastructure, Jadwiga Kroman - The City of Calgary - Transportation Infrastructure
The City of Calgary’s 12 Street Bridge is a new 170 m-long bridge carrying 12 Street S.E. over the Bow River, connecting St. George’s Island (home of the Calgary Zoo) to the historic community of Inglewood. The three spans of the bridge are composed of three variable depth (arched) rectangular steel box girders, and supported by conventional cast-in-place concrete abutments and piers. To minimize the amount of work required over the river, the design team chose to use full-depth, full-width, precast concrete deck panels. This represents the first time this type of construction has been used in Alberta in a continuous bridge. The panel-to-panel and panel-to-girder connections were cast-in-place using Ultra-High Performance Concrete (UHPC).
Although a first in Alberta, this solution has been used thus far on 200+ North American bridges. Many projects require Accelerated Bridge Construction (ABC) materials and methods, to ensure minimized user disruption and road closures. For this project, ABC methods allowed for a higher level of quality control on the deck construction and minimized the construction risk of placing a large volume of concrete over the Bow River. While deck panels joints can be detailed using standard HPC concrete (with compressive strengths around 45 MPa), the high compressive strength (160-200 MPa) and ductility of UHPC, simplifies the detailing, fabrication, and installation process
The paper includes a description of the 12 Street bridge structure with focus on design, detailing, and construction of the precast deck panels and their cast-in-place UHPC connections.
Information Management Research in the Construction Industry from 2011 to 2016 (GC44)
Ferzon Aziz - George Brown College
This paper examines information management (IM) research in the construction industry (CI) for the period 2011 to 2016 inclusive to identify research focus. The scope of this study targets all phases of a project and is based on the construction industry in North America. A structured process is used to select and analyse 168 articles from literature. The articles are analysed in the context of a spreadsheet matrix framework based on: (i) Articles bibliographic attributes (year and country); (ii) Industry perspectives (industry, organization, project, library, and personal); (iii) PMBOK process groups (initiating, planning, executing, controlling and monitoring, and closing); (iv) Functional IM Model perspectives (IM process, IM input and output, IM resources and IM constraints); and (v) Performance assessment methodologies (management, content, and infrastructure). The results indicate six emerging sub-themes and IM research focus from a construction project perspective, specifically in the project management-executing phase. There is focus on improving information access and dissemination, information value, Information as a Resource, ICT integration, and reducing IM complexity. There is little focus on assessing ICT (infrastructure), IM (management), and Information (Content). This paper identified research focus, emerging areas of interest, and areas that may require further research, which could be useful to IM researchers and managers of information.
Restrained Shrinkage Test and Lab Simulation of Miro-cracking Technology for Cement-stabilizing Soils (MA74)
Shenglin Wang - University of Waterloo, Hassan Baaj - University of Waterloo
Clay and silt composed pavement layers often present deterioration due to consolidation under load and by volumetric change along with moisture variation. Cement-stabilized base and subgrade were domumented to have higher stiffness and strength. However, higher rigidity and excessive strength may also lead to shrinkage and thermal cracking in stabilized layers at early service life, and will reflected upon surface layers. Pre-cracking, or micro-cracking techniques is one of the technologies discussed recently to eliminate the stress concentration and potentials for wide cracking in cement stabilized layers. The general procedure in field is to apply a vibratory roller (e.g. 12 ton) over the stabilized layer 24-72h after the final compaction. Afterwards, multiple hairline cracks will be created to relieve the shrinkage and tension stress concentrations; therefore the development of wide cracks can be controlled. However, researches are still demanding on cracking potential investigation; in particularly, the time and potential of tension cracks that may occur in stabilized soils. There are also limited researches which focus on lab simulations of the in-field pre-cracking process. In the following research, two kinds of soils from southern Ontario (clay and silt) were stabilized with 6%, 9%, 12% cement by weight, respectively. Soil beams were cut from standard compacted cylinder specimens after 7d of curing; and both ends of the beams were fixed to prevent length change. Wetting and drying cycles were then applied for the beams to evaluate shrinkage potentials. Meanwhile, micro-cracking process was simulated in lab for stabilized clay with higher shrinkage potentials. Soils were first stabilized and cured for 3d before the pre-cracking energy was applied on the top of soil cylinder specimens using a standard proctor rammer. Flexural strength of both micro-cracked and untreated stabilized soil beams were tested in 7d, 28d and 56d, respectively. Results indicated that the stabilization effectively improved the durability properties and rupture modulus. With the increase of cement content and curing time, the values can be further improved. Moreover, Blenheim clay with 12% GU treated NM (not micro-cracked) had relatively higher shrinkage potential. The proper amount of cement content for Dresden silt and Blenheim clay accounted for around 6~9%, and at least 9%, respectively. Generally, the study presented a preliminary research for restrained soil shrinkage discussion and also attempted to investigate the pre-cracking process in laboratory circumstances.
Parametric study on Post-earthquake fire behavior of steel moment resisting frames (ST70)
Anahita Norouzi - Concordia University, Amit Chandra - Concordia University, Ashutosh Bagchi - Concordia University, Montreal, Canada, Anjan Bhowmick - Concordia University
Performance-based design of structures against fire and seismic-induced fire is an important area that requires more attention. While experimental study is one of the most reliable methods to capture behavior of steel structures under fire, performing real case scenarios in laboratories is not economical due to expensive facilities required to conduct such a test. Nonlinear Finite Element (FE) analysis can overcome the limitation of experimental investigation and can be used to study the effect of fire on different steel frame configurations. In this paper, numerical models in ABAQUS were developed and validated with the results of experimental tests. Uncoupled thermal mechanical analysis scheme has been adopted in this study which requires prior heat transfer analysis of the structural elements. Then, an extensive parametric study is carried out on verified analytical models to investigate the structural response of frames with different configurations and various earthquake scenarios. The parameters considered in this study are: different span ratios, natural and travelling fire scenarios with varying vertical spread times. A suit of five near field and five far field ground motion records have been considered in the non-linear time history analysis. Finally, the deformation history, axial forces, bending moments and frame utilizations are analyzed to find correlation between the size and location of the fire. The obtained results are used to extract their statistical patterns and provide insights on these classes of problems.
Damage identification in structures using correlation-based technique (ST83)
Timir Baran Roy - Concordia University, Ashutosh Bagchi - Concordia University, Canada, Lucia Tirca - Concordia University, Canada, Shiv Singh Patel - CSIR-Central Building Research Institute, Roorkee, India, Soraj Kumar Panigrahi - CSIR-Central Building Research Institute, Roorkee, India, Ajay Chourasia - CSIR-Central Building Research Institute, Roorkee, India, Parth Vitthani - Institute of Technology Nirma University, Dhaval Patel - Institute of Technology Nirma University
The Finite Element (FE) model correlation and damage detection are important elements of Structural Health Monitoring (SHM). The feasibility of FE model correlation and modal identification as a tool for signal processing is explored here for locating structural anomaly. Anomalies can exist in a structure in the form of damage due to loss of stiffness in the structural and non-structural elements, and such anomalies alter a structure’s dynamic properties. Experimental and operational modal analysis are successfully used by many researchers to estimate modal parameters, such as: modal frequencies, mode shapes and damping to measure structural damages in experimental and operational conditions employing vibration-based response of the structures. This paper emphasizes the process of identification and localization of structural damages based on a correlation coefficient, termed as Damage Location Assurance Criterion (DLAC). The work further demonstrates the effectiveness of the method by using an experimental case study on a five-storey scaled steel prototype. Further, a comparative study of damage detection by using the mode shape curvature technique and the DLAC has been carried out. It is shown that DLAC can effectively identify structural damage based on the changes in modal frequencies between the damaged and the intact/undamaged structure.
The performance of semi-active MR damper improved by fuzzy logic based controller under seismic excitation (ST30)
Keyhan Faraji - Polytechnique Montreal, Ashutosh Bagchi - Concordia University, Canada, S. M. A. Salehizadeh - Wentworth Institue of Technology
Control systems play a crucial role in operation of airplanes, robots and new generation of smart automobiles, and improve their performance, safety and robust serviceability. Control systems are useful in structures improving their seismic performance. Although the use of dampers is becoming popular, the main issue with it is that most of such devices are in passive mode, without a control system. Therefore, they may sometimes cause detrimental effects. Magnetorheological (MR) damper is a type of semi-active dampers that can produce variable force according to the intensity of the magnetic field that is applied to it. Such magnetic fields can be produced by the DC current that can be provided by batteries. This means that it can be useful in harsh conditions in which the power supply may be interrupted. The capability of variable force production demanding less energy is the major advantage of MR dampers. In this research an intelligent control system based on fuzzy logic method is added to the MR damper system installed on a single story structure. Such a smart system makes the resisting damper force proportional to the magnitude of the earthquake records. Therefore, the damper force can be smartly controlled in real time by changing the applied electricity current to the damper according to the displacement of the structure, caused by an earthquake. The results illustrate that such innovative controllable damper can notably improve the seismic demand of the structure.
Keywords: MR damper, fuzzy logic, mamdani system, seismic loads, energy dissipation
Investigation on the Potential of Building Information Modeling in Structural Health Monitoring of Buildings (GC136)
Mojtaba Valinejadshoubi - Concordia University, Ashutosh Bagchi - Concordia University, Canada, Osama Moselhi - Concordia University, BCEE, Azin Shakibabarough - Concordia University
Structural health monitoring (SHM) has emerged as a useful structural evaluation technique to monitor the health of structures. Identifying the critical points of a building by doing an accurate structural analysis would lead to a reduction in the number of sensors installed for SHM purposes, which would ultimately decrease the overall cost of the SHM process. The main tasks in an SHM system include identifying the ideal placement of the sensors, installing the sensors, and capturing and storing their data for future retrieval. Building information modeling (BIM) has emerged as an effective data management tool. It can be utilized as a visual model as well as a repository for all data captured or made during the facility’s life cycle. This paper investigates the feasibility of using BIM in SHM of buildings. A case-study building is simulated in Autodesk Revit Structure 2017 and then exported to ETABS for structural analysis purposes, as well as to identify the ideal locations for installing SHM sensors, such as strain sensors. The model is then returned to Revit software to update the existing BIM model. Virtual strain sensors are modeled in Revit and placed in their designated locations. Some hypothetical data are assigned to the strain sensor —using the IFC file format of the BIM model. The sensor modeling and its associated data are validated by an external visualization tool—namely, the Solibri Model Viewer. A possible consequence of this research is that these integrated environments could be used as the basis for the integration of BIM and SHM into an efficient real-time monitoring system for a smart environment.
Keywords: Building information modeling; structural health monitoring; IFC; SHM sensors; smart environment
Investigating Different Image Processing Techniques for Better Interpretation of GPR Images (GC138)
Azin Shakibabarough - Concordia University, Ashutosh Bagchi - Concordia University, Canada, Mojtaba Valinejadshoubi - Concordia University
Nowadays bridge deck condition evaluation is carried out by some NDE techniques besides visual inspections. Among NDE techniques, Ground Penetrating Radar (GPR) is one the most powerful and versatile tools in this area. GPR scans the bridge deck surface and gives output in the format of the image. GPR image has low contrast, low brightness and some noises due to the limitation of illumination and environmental conditions. To mitigate these weaknesses, image processing techniques are applied. De-noising filters like Gaussian, Median, High and Low filter are used for GPR images, but each has a different result on the image. On the other hand, image enhancement techniques are utilized for increasing the quality of the image. Frequently, GPR image of reinforced (RC) concrete bridge deck shows some different layers from top to bottom respectively: deck surface, top rebar, bottom rebar, and bottom of the slab. The signal strength decreases with increasing depth of bridge deck, so bottom rebar owes to high depth cannot be seen clearly in the GPR scan. Image segmentation is one of image processing techniques which divides a GPR image by pixel to top and bottom layer. Then image enhancement is applied for making bottom rebar more visible. Image processing technique increases the reliability of visual inspection of GPR image. Hence, interpretation of a clear image has better result according to final condition assessment of RC bridge deck. In this paper, different techniques for noise filtration, image enhancement, and image segmentation tasks are investigated on a raw GPR image from a real case study (bridge deck) to indicate the combination of which techniques are more effective for producing a clear image for further analysis.
Keywords: GPR, image processing, bridge deck, bottom rebar
Stormwater Reduction by a Green Roof: A Comparison of Canadian Climates (GC156)
Ashkan Talebi - Dept. of Civil Engineering, University of Toronto, Denis O'Carroll - University of Western Ontario, Brent E Sleep - Civil Engineering Dept, University of Toronto, Scott Bagg - No Affiliation
In recent decades, urbanization has led to more frequent flood events in urban areas. To reduce the impact of urban floods, several measures have been taken, including the use of green roof technology. To investigate its feasibility in the Canadian climate, several cities across the country (Vancouver, Calgary, Regina, Toronto, London, and Halifax) were selected to determine the retention performance of green roof systems in different climates. The water balance equation along with evapotranspiration (ET) models were employed to simulate runoff that might be produced by green roofs in six Canadian cities. A seven-year simulation period was selected running from 2000 to 2006, with modeling conducted for eight months of the year, from March 1st to October 31st, using hourly time steps. The runoff simulations with the Penman-Monteith (PM) and Hargreaves-Samani (HS) models were carried out for hypothetical green roof setups incorporating two different types of vegetation. The results showed that the performance of green roof depends on location, varying from 17% to 50% for low water use plants. The best performance in storm water reduction (%) was predicted to occur in Regina and Calgary, while the poorest performance (%) was predicted for Halifax and Vancouver. The highest amount of runoff reduction (mm) was predicted to occur in Toronto and London. The predicted ET rates showed that both the PM and HS models predict similar ET rates in the studied Canadian cities.
The Impact of Pavement Condition on Road Safety in New Brunswick (TR42)
Arash Bagher Ghanbari - University of New Brunswick, Xiomara Sanchez - University of New Brunswick, Eric Hildebrand - University of New Brunswick, James Christie - University of New Brunswick
This study developed an understanding of the relationship between pavement condition and road safety on rural arterial and collector roads in the province of New Brunswick. The intent was to use this relationship for consideration as a decision-making criterion in asset management programs. Two crash prediction models were developed for single-vehicle and multiple-vehicle collisions using a negative binomial regression that relates pavement condition indicators to accident frequency. International Roughness Index was found to be significant in both models which indicate that IRI is a contributing factor to single-vehicle and multiple-vehicle accident involvements. It is noteworthy that the model coefficient for IRI was determined to be negative in both models which reflects that a higher number of collisions is expected to occur on road sections with smoother pavement surfaces. Crash modification functions were developed for both single-vehicle and multiple-vehicle collisions. The results indicate that a unit of increase in IRI in m/km is expected to decrease single and multiple-vehicle accidents by 7.7% and 14.8%, respectively. It was also found that the percentage of change in multiple-vehicle collisions due to pavement roughness changes, while all other variables in the models remain constant, is approximately two times greater than the percentage of change in single-vehicle accidents. According to the crash modification functions (CMF) associated with pavement age, the results indicated that collector roads are slightly more impacted by pavement roughness than arterial roads.
Evaluation of Innovative Solutions for Cycle Tracks at Bus Stops (Undergraduate Student Competition) (TR40)
Joshua Kamaras-Garland - Ryerson University, Mohammed Baig - Ryerson University, Jeremy Bertrand - Ryerson University, Nicolas Di Stefano - Ryerson University, Graham Marsden - Ryerson University, Khan Rafsanjani - Ryerson University, Said Easa - Ryerson University, Canada, Christina Bouchard - IBI Group
Existing conditions in the City of Toronto host very poor transportation infrastructure when relating to the interaction between buses and cyclists. Toronto has not yet caught up to the paradigm shift that sees larger cities preferring alternative modes of transportation, such as public transportation and cycling over a personal motor vehicle. In these cities, new construction and retrofit projects no longer prioritize private vehicles, but instead they are being designed for all modes of transportation. Case studies of Copenhagen, Amsterdam, and Sydney were investigated to observe how other regions are addressing the issues that will be evaluated in this project. Local and provincial policies were reviewed to ensure our designs are all compliant with all applicable standards. Such regulations include the Accessibility for Ontarians with Disabilities Act (AODA), The Ministry of Transportation of Ontario’s Traffic Manual, and the City of Toronto’s Vision Zero guidelines for reducing road related fatalities.
This paper focuses on issues relating to bus stops on routes with protected cycle tracks, and proposes alternatives to improve the safety and functionality of these facilities. The goal of this report is to create a standard that the City of Toronto can implement on any cycle track. Four alternatives are proposed: A cycle track going around a protected island for bus passengers to wait at; a cycle track going around the stopped bus; a bus stop fully within the cycle track; and a complete relocation of a cycle track to the left lane on one way streets. The site being evaluated for the implementation of these alternatives is 317 Adelaide Street West, Toronto, Canada. Qualitative and quantitative analyses were conducted, focusing on the following factors: Improving safety through the elimination or reduction of conflicts involving vulnerable road users; optimizing traffic and bus operations; and improving the accessibility of the facility for users of all ages and abilities. The recommended solution is a combination of the passenger island and bus stop in the cycle track. Both alternatives provide improved safety and functionality and together they can be implemented in any region of the city.
Structural Health Monitoring System and Expansion Joints of Montreal's New Champlain Bridge (GC180)
Parinaz Pakniat - Mageba, Gianni Moor - Mageba, Borja Baillés - Mageba, Alexis Lauzon - Mageba
The construction of the new Champlain Bridge in Montreal, to carry approximately 160,000 vehicles per day across the St. Lawrence River, is a key element of one of Canada’s largest current infrastructure projects. The expansion joints and structural health monitoring (SHM) system selected for use in the bridge’s construction and maintenance shall be described.
Tunnel segment gasket design – solutions and innovations (GC5)
Mehdi Bakhshi - AECOM, Verya Nasri - AECOM
Watertightness of tunnels must be ensured during design and construction to prevent water infiltration and minimize maintenance and repair costs, maintain operational safety, and protect inside equipment. In one-pass segmental lining system, watertightness is guaranteed by segments and gaskets placed between segments joints. In this paper, a procedure is provided to select gasket materials, solutions for different working water pressures, appropriate safety factor considering relaxation, and gasket profiles considering size of tunnel, tolerances and required construction gap/offset. Watertightness tests, gasket load-deflection tests, and details of gasket groove design are discussed. Gasket short-term behavior was provided in terms of a load-deflection curve, and discussion is made on design of connection systems for maximum gasket load in this curve or in a less conservative approach after short-term relaxation. Gasket groove design is briefly explained with a focus on simulation of impact force in a gasket groove as a hydrostatic distribution. New developments in gasket systems are introduced including anchored gaskets and most recently developed fiber anchorage technology for gaskets; soft corner solutions to eliminate point loading using pin-based cavities; and new repair method for post sealing of segment joint based on direct drilling and injection through joint sealing gasket.
Mechanical Properties of Concrete with Recycled Shredded Rubber Particles (MA32)
Kumari Bandarage - Dalhousie University, Pedram Sadeghian - Dalhousie University
The number of waste tires from vehicles are continually increasing in the world and disposal of waste tires has become a global problem and required to find an adequate recycling system. As a method of recycling of waste tires, rubber particles of tire can be used in concrete and it has become a preferable solution for disposing waste tire. The goal of this research is to study the mechanical properties of recycled rubber particles extracted from scrap tires in concrete to introduce a sustainable waste management system and subsequently to reduce the use of non-renewable resources in concrete. In this paper, fine aggregates of concrete are partially replaced with recycled shredded rubber particles less than 6 mm in size. Concrete cylinders with different proportion of rubber are prepared and tested under compression. Also, specimens without rubber are prepared and tested as control specimens. The strength, stiffness, and energy absorption of the specimens are analyzed to characterize the behaviour of concrete with recycled shredded rubber particles. This is an on-going research and more results will be provided in the full paper.
Investigation of Structural Properties for Lightweight Concrete produced by using local lightweight Aggregate Cicolite and Expanded Perlite (ST6)
Ghanem Banhidarah - University of Dammam
Due to the fact that concrete is the most widely used construction material in Saudi Arabia (SA) and the world which have heavy weight. Since the major component of concrete is the aggregate with variety of lightweight aggregate (LWA) types available in SA, This research comes to focus on the selection of the best LWA to produce lightweight concrete (LWC) through replacing of normal coarse aggregate by two lightweight materials are available in SA (Expanded Perlite and Cicolite), by mixing different percentages starting from 50% to 100%. And investigate the mechanical properties thought laboratory experiments for different curing periods of 7, 28, and 90 days. The results indicate that 50% Cicolite replacement is the best replacement percentage for structural aspects of reduction in density 13.2% comparing with normal coarse aggregate (2150 kg/m3) and achievement percentage of design strength at 28 days is more than 31%. For nonstructural aspects 100% of Expanded Perlite replacement is selected of density 1400 kg/m3 lower than normal mix by 43% with compressive strength of 13.7 MPa. Which will reduce structure own weight, reinforcement needed, cross-sections size, and materials used.
Also is expected to have less heat transfer which mean less cooling loads and that shown in the reduction of electrical consumption. This will be more economical and environment friendly than conventional concrete. It will also open doors for further researches in other types of materials available in Saudi Arabia with different percentages of design and mixing.
Experimental Study on Structural Behavior of Concrete Masonry Beams (GC34)
Jamshid Zohrehheydariha - University of Windsor, Eric Hughes - University of Windsor, Sreekanta Das - University of Windsor, Bennett Banting - Canada Masonry Design Centre
This paper presents the effect of the grout strength and the block unit size on the structural behavior of masonry beams constructed in the traditional running bond and compared with similar masonry beams constructed in stack pattern. Canadian standard, CSA S304 does not allow stack pattern masonry beams to be designed and built. Since the head joints in stack pattern masonry line up vertically, it is believed that this construction is weaker than the traditional running bond construction. Many architects prefer the stack pattern masonry look for aesthetic purposes not considering the structural limitations. A total of eight full-scale masonry beams were tested in the structural engineering laboratory of University of Windsor detailed with both running bond and stack pattern coursing under the scope of this study. Test data were collected using loadcells, strain gauges, displacement transducers, and digital image correlation (DIC) technique. The DIC technique was implemented to effectively monitor the crack pattern and crack growth on the masonry beams and prisms. This study found that the strength of the grout has the largest effect on the structural performance of masonry beam specimens. There is no significant difference in the structural behavior of masonry beam specimens constructed in the stack pattern and running bond despite the fact that the cracks at the head joints of the stack pattern beam specimens initiated at lower loads.
Modelling of meandering river dynamics in Colombia: A case study of the Magdalena River (DM3)
Laura Isabel Guarín - Universidad Nacional de Colombia, Juliana Vargas - Universidad Nacional de Colombia, Simón Barreneche - Universidad Nacional de Colombia, Philippe Chang - Universidad Nacional de Colombia Sede Manizales
The analysis and study of Open Channel flow dynamics is centered on flow modelling using discreet numerical models based on the constitutive hydrodynamic equations.
The overall spatial characteristics of rivers, i.e. its length to depth to width ratio generally allows one to correctly disregard processes occurring in the vertical or transverse dimensions thus imposing hydrostatic pressure conditions and considering solely a 1D flow along the river length. Through a calibration process an accurate flow model may thus be developed allowing for channel study and extrapolation of various scenarios.
The Magdalena River in Colombia is a large river basin draining the country from South to North over 1550 km with an average slope of 0.0024 and an average width of 275m. The river displays high water level fluctuation and is characterized by a series of meanders.
The city of La Dorada has been affected over the years by serious flooding and severe erosion. As the meander is evolving at a steady pace such events have endangered a number of neighborhoods.
This study has been undertaken in order to correctly model the flow characteristics of the river in the region hence allowing for a detailed evaluation of various scenarios and providing decision makers with erosion control measures options and a forecasting tool.
Two field campaigns were completed over the dry and rainy seasons including extensive topographical and channel survey using Topcon GR5 DGPS and River Surveyor ADCP. Also, in order to characterize the erosion process occurring trough the meander, suspended and bed load samples were retrieved and soil perforation tests have been carried out over the banks.
Based on the digital elevation model and field data a 2DH flow model was prepared using the Iber freeware founded on the finite volume method in a non-structured mesh environment.
The calibration process was carried out comparing field and available historical data of a nearby hydrologic gauging station.
Although the model was able to effectively predict overall flow processes in the region, its spatial characteristics and limitations related to pressure conditions did not allow for an accurate representation of erosion processes occurring over specific bank areas and dwellings. As such a significant helicoidal flow has been observed through the meander. Furthermore, the rapidly changing channel cross section as a consequence of severe erosion has hindered the model’s ability to provide decision makers with a valid up to date planning tool.
The History Program of the Canadian Society for Civil Engineering (GC175)
Alistair MacKenzie - Ryerson University, Canada, Michael Bartlett - University of Western Ontario
This Case Study examines the origins of the Society’s National History Program, summarizes the current state of the program and looks at its future plans;
ESTABLISHMENT OF THE PROGRAM:
Shortly after the Canadian Society for Civil Engineering was reconstituted in its present form, several members suggested that there was a need for a history program. There was a belief that many civil engineers had little knowledge of the achievements of their predecessors.
The follow up came in 1982 when the late W. Gordon Plewes was asked to develop an appropriate history program. In May of that year a meeting was convened to explore how this could be accomplished. Following this meeting the National History Committee was formed
The National History Committee has continued operating from that date with a Mandate updated to reflect current events and activities.
This is a “mainstay” of the program and to date 75 National, International and Regional Historic Sites have been recognized.
In 1992, the Society created a History of Civil Engineering Award, named in commemoration of Gordon Plewes.
Nomination of Boundary Layer Wind Tunnel Laboratory as a CSCE/ASCE International Historic Site (GC104)
Michael Bartlett - University of Western Ontario, Sangie Zaitsoff - University of Western Ontario, J. Peter C. King - University of Western Ontario
The Boundary Layer Wind Tunnel Laboratory at the University of Western Ontario has been nominated as a CSCE/ASCE International Historic Site. The paper and presentation will briefly chronicle the history of the laboratory, including some of the contributions to the science of wind engineering made there.
Curvature Ductility of Concrete Columns with Low Axial Loads (ST66)
Marcie van Weerdhuizen - University of Western Ontario, Michael Bartlett - University of Western Ontario
Quantification of curvature ductility in concrete columns provides a basis for more accurately describing the warning of failure of a structural element. Curvature ductility, defined as the ratio of ultimate curvature to yield curvature, is a metric for warning of failure. In this study, cross sections having total reinforcing ratios ranging from 0.01 to 0.04, normalized spacing of outermost reinforcing layers, γ, ranging from 0.6 to 0.9, and concrete strengths ranging from 25 to 50 MPa are considered. Using typical idealizations for ultimate and yield moment calculations, cross sections were analyzed under a range of axial forces. The maximum axial load was taken as that corresponding to the balance point, where concrete crushing and steel yielding occur simultaneously. Curvatures at ultimate and yield limit states for each combination of parameters were used to form generalized equations for ductility ratios using multiple linear regression. Response-2000 analysis of an array of cross sections was used to validate the results independently. The generalized equations were found to be consistent lower bounds to the Response-2000 results. Curvature ductility ratios from one to twenty-five were observed over the parameter ranges considered. High ductility was observed for low axial loads, where behavior approached that of a beam in pure bending. Maximum ductility was achieved when the lever arm created by the outermost layers of reinforcement was large and the reinforcing ratio was small. Curvature ductility decreased with greater axial loads. Trends in observed ductility ratios allowed the warning of cross-section failure to be quantified using the basic parameters investigated.
Effect of Age Hardening on Modulus of Warm Mix Asphalt Mixtures (MA27)
Pezhouhan Tavassoti-Kheiry - The Pennsylvania State University, Ilker Boz - Michigan State University, Mansour Solaimanian - The Pennsylvania State University, Saman Barzegari - The Pennsylvania State University
Within the past two decades, various warm mix asphalt technologies (WMA) have been introduced with the goal of mix production at lower temperature as compared to the traditional hot mix asphalt (HMA). Effect of the WMA additives on the rheology of binders and mechanical properties of the mixes have been well investigated by several researchers. However, studying the effect of age hardening on the mechanical properties of the compacted WMA mixes has not been adequately researched. This paper presents the results of an experimental study on changes in shear and Young’s dynamic modulus of three popular WMA technologies in the United States as well as a control HMA over a period of four years. To this end, small scale cylindrical specimens were prepared and studied in the laboratory. A chemical additive, a wax-based additive, and water foaming process were utilized in preparation of the specimens. The specimens were tested for properties at various time intervals. Modulus was measured right after preparation and laboratory short term conditioning, then at subsequent intervals after production: two years, and four years. The results indicate different trend of hardening with respect to the modulus across the technologies within the range of this study. Impact resonance (IR) tests at three temperatures of 10, 25, and 40oC were conducted on the replicates to non-destructively measure the shear and Young’s modulus values of the specimens. IR results indicate that the trend of changes in modulus with time is different among the mixes.
Keywords: Dynamic Modulus, Impact Resonance Test, Warm Mix Asphalt, Age Hardening
Evaluation of Climate Impact on Pavement Performance in the United States (TR4)
Alexa Raffaniello - Manhattan College, Matthew Bauer - STV Inc., Mohab El-Hakim - Manhattan College
This paper analyzed four Long-Term Pavement Performance (LTPP) sections located in California and New York. Two selected sections are located within 1 mile on I-5 in northern California and two sections located within 1 mile on US-4 in northern New York. Sections located in the same state were subjected to identical traffic spectrum but exhibited variation in structural capacity. Two levels of analysis were performed in this study: a) in-state analysis and b) cross state analysis.
The in-state analysis focused on comparing the two sections located in each state. Sections located in California exhibited insignificant variation in thermal crack resistance regardless of the presence of additional 1.5” Asphalt Concrete (AC) layer in one section. On the other hand, the additional 1.5” AC layer resulted in significant reduction of rutting depth. The in-state analysis of sections located in New York concluded that chip seal layers has significantly low resistance to thermal cracking and rutting.
The cross state analysis examined two sections of comparable structural capacity. The two structurally weak sections (sections 06-0606 in California and 36-A350 in New York) proved that chip seal layers exhibit significantly high rutting depth even under high traffic loads in freezing climate compared to low traffic sections with regular HMA in warmer climate. The analysis of strong sections in California and New York concluded that properly designed and constructed HMA in freeze climate exhibits equal thermal cracking resistance as sections in no-freeze zones. Furthermore, the paper presents pavement deterioration models for LTPP sections using linear regression.
The Effect of a Temporary Lane Blockage on an Urban Network (GC95)
Hao Liu - The University of Texas at Austin, Randy Machemehl - The University of Texas at Austin, Carolina Baumanis - The University of Texas
Most cities have procedures that allow private construction activities to “rent” public street lanes to facilitate construction activity. Temporary blockage of lanes due to public or private construction activity can cause a variety of impacts from lane changing to path changing that generally cause traveler delay. This paper proposes a comprehensive framework to investigate the impact and compute the user cost as a result of the blockage. In this study, the impacts of blocking an arterial street lane in an urban network were examined in terms of path choice and traffic delay using a network dynamic traffic assignment (DTA) model called VISTA and a microscopic traffic simulator called CORSIM. The methodology brackets the impacts by allowing path changing by all vehicles through DTA (best delay case) and no path changing through CORSIM (worst case). The City of Austin's downtown VISTA DTA network was used as an example to demonstrate the impact of a temporary lane blockage on path choice and Total System Travel Time for a range of travel demand scenarios. DTA likely underestimates the impact in terms of delay because all travelers change paths to achieve the shortest travel time, which does not necessarily reflect what happens in reality. In considering a volume to capacity (v/c) ratio < 0.2, there was hardly any increase in Total System Travel Time from the blockage on Downtown Austin's mostly grid network, meaning that there was no real change in network delay. To explore the worst-case scenario, CORSIM was used and demonstrated that delay triggered by the blockage increases with volume to capacity (v/c) ratio. When the v/c ratio reaches and exceeds capacity, the additional delay becomes extreme. Further, the CORSIM simulation experiments varied the total length of the lane blockage with respect to a fixed position on the intersection block. The last set of CORSIM experiments maintained a constant blockage length but changed the position of partial lane blockage on intersection block. These experiments led to the confirmation of threshold values for critical blockage length and distance from the intersection. These threshold values could be considered when computing temporary lane blockage fees. User delay in terms of the monetary value of a person's time was used to calculate the cost of the additional delay due to a blockage. The knowledge gleaned from the threshold CORSIM experiments can help improve temporary lanes blockage management make better decisions that aim to minimize overall user delay.
Comparing Cyclist Behavior Among Three Urban Test Beds in Austin, TX (GC86)
Carolina Baumanis - The University of Texas, Jenny Hall - The University of Texas at Austin, Randy Machemehl - The University of Texas at Austin
In comparison to cars, cyclists are in many ways much more exposed to the potential dangers of the road. The explicit indication of traffic signals and other devices enhance safety by clarifying how the users of the transportation system should act as operators. While past studies have evaluated control devices and their impact on cyclist behavior, experimental set-ups have been typically chosen to ensure that environmental conditions remain the same between tests. Bicycle facility treatments can be thought of as a hierarchy, ranging from no treatment to bicycle signals, raised buffers, and more. Cyclist behavior can vary depending on the type of treatment present. Additionally, the existing road environment in which the treatments are placed will also have an effect on cyclist behavior. The objective of this experiment was to observe cyclist behavior in three different urban environments with three levels of existing treatments ranging from no treatment to bicycle lanes with raised buffers. This study aims to show how different level of facility treatment (none, medium, and high) affects cyclist behavior and overall cyclist safety. The total number of cyclists, vehicles, acts of non-compliance, and unsafe passages through the intersection were obtained from video data. Unsafe passage was considered as the total occurrences of non-compliance, one-party reactions, and two-party reactions. Here, we assume that a non-compliant passage is less safe than compliant passage, and therefore categorized as an unsafe passage. One- and Two-party reactions are defined as when either or both a cyclist and vehicle change their path and/or speed because of a perceived danger, respectively. Regular yielding behavior was not counted as neither a one nor two party reaction. Non-compliance and one/two-party reactions were analyzed as types of unsafe passages. The aggregated data were evaluated for three different test beds in order to observe the changes in cyclist behavior and safety. Simple linear regression models were built to unveil cyclist behavior during the 24-hours, peak versus off-peak hours, and daytime versus nighttime hours. The models were built using simple linear regression to produce cyclist behavioral trends, not necessarily predictive equations. This experiment found that unsafe passages per cyclist decreased as vehicle lane volumes increased in low and medium bicycle stress level locations. This experiment also revealed that the higher the qualitative level facility treatment, the more likely that a linear correlation exists between the aforementioned variables in the daytime versus nighttime and peak versus off-peak hours. Finally, unsafe cyclist passages increase as the number of cyclists when there is no treatment present.
Alternative Designs of Multi-Span Continuous Concrete Girder Bridges with Semi-Integral Abutments (ST50)
Claire Wallis-South - Ryerson University, Sameh Salib - Ryerson University, Khaled Sennah - Ryerson University, Niloofarsadat Heirani - Ryerson University, Pino Carnovale - Ryerson University, Jafar Bayat - Ryerson University, Sama Honarpour - Ryerson University, Seyed Saeed Naseri - Ryerson University
In recent years, it has become more and more evident that transportation infrastructure in the Greater Toronto Area (GTA) has not expanded cohesively with the growth of populations outside of the downtown core. The capacity of existing roadways has been reached and the need for new infrastructure to alleviate congestion is immediate. Residential and commercial growth in areas north of the GTA has created congestion on the Don Valley Parkway (DVP), an arterial route connecting the northern and southern parts of Toronto, requiring an extension of Highway 404. This paper presents a summary of the undergraduate capstone project on alternative designs of a multi-span continuous CPCI semi-integral abutment bridge that would allow crossing of major roadways in developed areas for the highway extension. A key concept of the semi-integral abutment bridges is the offset of conventional expansion joint to the outside of the structure envelope by extending the superstructure over the abutments and introducing vertical (ballast) walls. This shields major bridge components (e.g. bearings) against water leaks/corrosion over the long-term serviceability of the bridge. Further, providing controlled drainage outside of the superstructure by means of granular backfill/sub-drains, in turn decreasing the potential for significant future maintenance cost and lack of structural integrity and serviceability. This bridge type also allows for longitudinal movements through sliding bearings. Consequently, the entire bridge structure is relieved from significant straining actions that could have been induced due to thermal and creep/shrinkage effects, especially for precast/prestressed concrete systems. To develop a design that would best fit the project needs, two alternative deck structures using CPCI girders were evaluated; Prestressed Concrete I-Girder and Prestressed Concrete Box-Girder. In addition, the possibility for using the recently developed NU I-Girder was explored. NU I-Girders provide several advantages to structural design, especially their ability to accommodate longer spans while maintaining, or reducing, the bridge depth as for CPCI girder design. Exploring this alternative allowed comparing between new girder technology and conventional systems used for precast/prestressed concrete superstructures. Structural analysis was performed through finite element modelling and design was accomplished using the CHBDC (Canadian Highway Bridge Design Code). The optimal girder option was then selected based on a comprehensive comparison criterion that considered cost, durability, and ability to maintain flow of traffic over the course of construction among various other comparison aspects. It is believed that the presented study provides useful guidance to the designers of precast/prestressed concrete bridges.
Selection of Allowable Release Rates for Stormwater Management Facilities – A Case Study, City of Red Deer, Alberta, Canada (GC139)
Manas Shome - Matrix Solutions Inc., Brandyn Coates - Matrix Solutions Inc., Ward Yurystowski - City of Red Deer, James Beck - City of Red Deer
Urban development typically results in increased peak flows and volumes of stormwater runoff due to an increase in imperviousness of the area. The increased quantity and peak flow may result in erosion and flooding of the receiving watercourses, unless proper mitigation measures are in place. Typically, stormwater management facilities are constructed to store runoff during rainfall events and discharge retained water at a specified release rate to minimize impacts to the downstream environment. The allowable release rates and storage requirements for SWM facilities are determined based on analysis of pre-development peak flow rates within a watershed and considering physical conditions of the receiving watercourses and water bodies. The allowable release rates from SWM facilities need to be equal to or less than the pre-development flow rates and are usually approved by the appropriate regulatory body.
Pre-development peak flow rates for a watershed of any size are typically determined from statistical analysis of streamflow data and expressed in a unit area rate (e.g. L/s/ha). A constant peak flow rate per unit area is then used to compute allowable release rates from SWM facilities. In this study, it is demonstrated that peak flow rates per unit area decrease as drainage areas and thus the peak flow rate per unit area needs to be selected based on the size of the developed area in computing total release rate from a SWM facility. The range of computed release rates, physical characteristics of the receiving watercourses, and downstream flooding potential were considered in selecting allowable release rates. In addition, a cost-effective release rate per unit area based on optimization of land requirements for SWM facilities and sizing of downstream conveyance infrastructure was also considered in selecting the allowable release rates from the SWM facilities.
In this presentation, an overview of the study area will be provided, including the hydraulic and physical conditions of important natural watercourses and waterbodies, and the methods along with study findings will be presented. Finally, it will be demonstrated that the variable peak flow unit area rate approach used in this study resulted in allowable release rates that were practical, environmentally defensible, and this method should be considered for determining allowable release rates and for sizing SWM facilities in the future.
Increasing rotational capacity of gusset plates through heat treatment (ST37)
Hossein Mohammadi - McMaster University, Tracy Becker - McMaster University, Hatem Zurob - McMaster University
Gusset plates play an important role in the performance of braced frames in earthquakes. They typically are designed to bend as the brace buckles without fracture or causing damage to the beam or column. This has been achieved by other researchers by proposing various geometries for gusset plates with linear or elliptical fold lines. In this paper, a new approach is proposed in which, starting with a structural high strength steel, the desired yield path of the gusset plate is created through heat treating to locally weaken the steel and, at the same time, make it more ductile. Through this method, the gusset plate is forced to yield and deform over the predetermined path. The objective of the research is to develop a connection in which the failure mechanism is tightly controlled, eliminating unexpected damage mechanisms and aiming for more economical designs. First, small steel samples were heat treated using different time-temperature profiles to determine the potential strength reduction. Based on the initial results, localized heat treatment was performed on coupon test samples, and tensile tests were used to quantify the change in material properties. Using these properties, finite element analysis of the gusset plate-brace connection is performed to investigate the behavior of the proposed gusset plates. Various gusset plate geometries and yield paths are subjected to a series of loading. The analysis results including the predicted failure mechanisms are presented and used to make recommendations for the heat treated gusset plate design.
Traditional vs Column Top Isolation for Typical Structures (ST67)
Richard Darlington - McMaster University, Tracy Becker - McMaster University
Traditional installations of base isolation can be expensive, especially in retrofit applications. Addition of a rigid diaphragm above the isolation layer, excavation of a seismic moat, and extensive foundation work increase construction time and costs. As a result, isolation retrofit projects are typically limited to buildings with historic significance and large budgets. Limiting the use of isolation to new and/or large budget structures means fewer buildings are likely to remain functional post-disaster, decreasing community resilience during large earthquake events. To make isolation retrofit accessible to a wider range of structures, the up-front costs must be reduced. This can be achieved by placing bearings on column tops, forgoing the need for construction of a seismic gap and an additional rigid diaphragm. However, columns under the isolation layer may be flexible, changing the traditionally assumed bearing end conditions. To assess the viability of column-top isolation, the performance of a pre-Northridge steel moment resisting frame office building, designed to the 1965 National Building Code of Canada (NBCC), is compared against a column-top retrofit with stiffened first floor columns and a traditional base isolation retrofit design using lead-core rubber bearings. This study also explores the impacts of gravity frame modelling assumptions in moment resisting frame structures on the performance of the isolated systems. Suites of ground motions representing different fault types were selected and scaled to hazard levels prescribed in the 2015 NBCC. Using a nonlinear time history analysis in OpenSEES, the overall seismic performance of column-top isolation was investigated.
Predicting Bridge Bearing Demands Through a Probabilistic Framework (ST65)
Bryanna Noade - McMaster University, Tracy Becker - McMaster University
The age at which bridge bearings are replaced is determined through field inspection and engineering judgement with no real information on remaining performance. Bridge bearings are expected to be replaced once during a bridge’s lifetime; however, having a more specific timeline will aid in forecasting maintenance schedules and costs. Quantifying and compiling the cyclic load demands of a bearing, such as horizontal displacement and vertical compression, is the start to determining the life expectancy of bridge bearings. Temperature fluctuation and seismic events represent the major demands on bridge bearings within Ontario, with contributions of each depending on location. A framework for quantifying the probabilistic lifetime demands for cyclical displacement of bridge bearings is presented by combining the effects of the loading types on a model of a multi-span girder bridge. The probabilistic lifetime bridge loading combines the multiple loading scenarios specific to a location. The output will represent the annual displacement cycles experienced by the bridge bearings, with information on the relationship between the number and amplitude of cycles. By obtaining the lifetime displacement demands on a bridge bearing the replacement time can then be projected.
The Effect of an activated carbon (GAC) filter on the microbial Quality of water (EN41)
Mojtaba Behboud ahani - Islamic Azad University
Water is a component of the environment, that its quality is influenced by the health of the environment. On the other side, improving environmental health is also directly related to the quality and quantity of water. A healthy water resource must be able to supply safe and sufficient water for the society. For this purpose, the resources have to be under monitoring and control of health responsible regularly; so that by being aware of the presence of any potential contaminants in water, control measures should be applied. Provision of safe water and proper management of wastewaters play the major role in reducing water-related infectious diseases. A set of measures for improving the environment and the health, safe and adequate water supply can reduce 40 to 100% of water-related communicable diseases. In this study, the effect of active carbon, as an actual absorbent, on the elimination of turbidity, colour, taste and smell have been investigated in order to improve the quality of drinking water. The results of the study indicated that active carbon, as a strong absorbent with high porosities and the broad lateral surface is effective to eliminate turbidity, colour, and smell.The use of GAC under specified conditions was proposed by the U.S. Environmental Protection Agency (EPA) as the option of choice for the control of "synthetic organic chemicals" in drinking water. During the subcommittee's study, the EPA held hearings and received written comments regarding this treatment. The subcommittee reviewed the pertinent literature and rigorously assessed the scientific database. Its scope of work included a review of work on adsorption efficiency microbial activity on adsorbents, physiochemical interactions, regeneration of adsorbents, analytical methods to monitor adsorption processes
Performance and Damage Assessment of GFRP-RC Walls (DM45)
Nayera Mohamed - Universite de Sherbrooke, Murat Saatcioglu - University of Ottawa, Ahmed Farghaly - University of Sherbrooke, Brahim Benmokrane - Universite de Sherbrooke
The performance-based assessment and design become more wide-spread in structural engineering practice. The relationship between deformation limits and performance levels (immediate occupancy, life safety, and collapse prevention) are reasonably well established for steel-reinforced concrete (RC) walls. However, performance of RC walls reinforced with fiber-reinforced-polymer (FRP) bars can be substantially different. Four full-scale shear wall specimens were tested; two specimens were reinforced with glass-FRP (GFRP) bars, while the other two specimens were reinforced with steel bars. Analysis of the experimental observation defined the three performance levels and compared to the specified limits provided in the ASCE/SEI 41-06 in the drift ratio format. It was found that, the GFRP-RC shear walls developed significant deformability, exceeding the ASCE/SEI 41-06 deformation performance limits due to the elastic nature of the GFRP bars. This suggested proposing new deformation limits for the GFRP-RC walls associated with the damage description of each of the three performance levels.
Cyclic Bond Behavior of Different GFRP Bar Types (ST129)
Nayera Mohamed - Universite de Sherbrooke, Ahmed Farghaly - University of Sherbrooke, Brahim Benmokrane - Universite de Sherbrooke
To enable conducting dynamic analysis of recently developed Fiber-Reinforced-Polymer (FRP) reinforced concrete (RC) shear walls, squat walls, and frame structures, bond stress-slip hysteretic behavior need to be investigated. Bond-slip relationship between reinforcement and the concrete under cyclic loads influences bond strength, cracking and deformation of such FRP-RC structures. To determine bond characteristics depending on the real case; a novel cyclic beam testing method was developed and assessed to obtain accurately the bond performance of FRP bars in reinforced concrete members under cyclic bending actions. Experimental results of twelve specimens are presented herein with different glass-FRP (GFRP) bar coating and compared with the bond behavior of deformed steel bar. The tested parameters were; FRP bar coating (sand-coated, helically wrapped, deformed bars), and loading conditions (monotonic loading, tension-tension cyclic loading, and tension-compression reversed loading). The influence of different parameters affecting bond between FRP and concrete is discussed through analyzing the failure mechanism, the average bond stress-slip curve, and local bond stress distribution along bonded length. The results showed that cyclic loading had a significant influence on the bond behavior as well as the slip of GFRP bars embedded in concrete. GFRP sand-coated bars and helically wrapped bars showed better bond behavior than that for deformed bars even for steel bars. Based on experimental results, a bond-slip model is proposed using a trilinear model with emphasis on case of reversed loading. The bond–slip relationship can be utilized for evaluating the seismic behavior and bond degradation response of bond-critical regions in reinforced concrete members when confined internally with steel ties or fiber reinforced concrete.
Strength and Deformation of Well-Confined GFRP-Reinforced Shear Walls (ST128)
Ahmed Hassanein - Université de Sherbrooke, Nayera Mohamed - Universite de Sherbrooke, Ahmed Farghaly - University of Sherbrooke, Brahim Benmokrane - Universite de Sherbrooke
Well-detailed reinforced concrete structural walls are the most common lateral force-resisting system in reinforced concrete construction, expected deformability and high lateral stiffness make them effective especially in high seismic regions. Recent studies have shown an acceptable level of strength and deformability of shear walls reinforced solely with glass fiber-reinforced-polymer (GFRP) bars. The GFRP bars have emerged to be one of the most promising construction materials for reinforcing of different structural elements. Considering the aspects that still need to fully understand this new seismic resistance system, the primary objective of the current study is to enhance the deformability capacity of the shear walls reinforced with GFRP bars. Four Full-scale shear-wall specimens reinforced with GFRP bars were built and loaded to failure under cyclic lateral loads and constant axial load. The main objective of this study is to investigate the effect of the confinement configuration on the seismic behavior of the tested walls. The experimental results of the tested walls have showed an enhancement in the drift ratio and ultimate strength with the increase confinement level.
Adsorption and advanced oxidation processes for treatment of 17beta-estradiol and its metabolites (EN23)
Jessica Bennett - Dalhousie University, Allison Mackie - Dalhousie University, Yu Ri Park - Dalhousie University, Graham Gagnon - Dalhousie University
Recirculating aquaculture systems (RASs) allow food fish to be grown in a contained system with minimal water use (up to 99% recirculation) and a small land footprint. Recently, estrogens have been used to feminize and increase growth in American Eels being grown in a RAS. The main objective for this study was to reduce concentrations of estrogens in wastewater (17beta-estradiol (E2) and its metabolites estrone (E1) and estriol (E3)) to predicted no effect concentrations (PNEC; < 1 ng E2/L, < 6 ng E1/L, < 60 ng E3/L) in order to assure stakeholders that no detrimental environmental effects will come from discharging this waste stream. Both adsorption using granular activated carbon (GAC) and advanced oxidation processes (AOPs), including UV, ozone (O3), and UV with addition of hydrogen peroxide (H2O2), have been previously shown to effectively adsorb or degrade trace organic contaminants. This study tested adsorption and advanced oxidation processes for the removal of low concentrations (10 and 0.10 µg/L) of 17beta-estradiol and its metabolites. Estrogen concentrations were analyzed using liquid chromatography/tandem mass spectrometry (LC-MS/MS). GAC, organoclay, and montmorillonite clay were not effective at removing estrogens to below detection limits. Increasing UV dose from 100 to 1000 mJ/cm2 increased degradation of estrogens tested to near or below detection limits. Adding H2O2 increased the efficacy of the UV treatments. Ozone removed all estrogens from solution at a low dose of 1 mg/L. The results of this study indicate that AOP water treatment processes are effective at degrading E1, E2, and E3.
Development of a Test Method for Strain Rate Testing of Flax FRPs in Direct Tension (ST57)
Dillon Betts - Dalhousie University, Pedram Sadeghian - Dalhousie University, Amir Fam - Queen's University
Materials typically exhibit higher strength and stiffness when loaded under a high strain rate. Therefore, to accurately predict impact response of structures, it is important to understand the effect of strain rate on the mechanical behaviour of constituent materials. In this study, a test method is developed to test the effect of strain rate on the tensile behaviour of flax fibre-reinforced polymers (FFRPs). A total of 20 test specimens will be prepared for these tests, the main parameter being the thickness of the FFRP (one, two or three layers of bidirectional flax fabric). The test method was developed because the available equipment was unable to test at high strain rates. The new test method uses a drop weight to break a tensile specimen. The top of the test specimen is securely connected to a load cell and a test frame. The bottom of the test specimen is connected to a drop weight. To achieve varying displacement rates, the weight and drop height can be adjusted. The system is currently being verified by testing aluminum specimens with well known static properties. Once verified, the system will be calibrated by testing additional tension coupons with a variety of drop weights to determine what weight is required to achieve each desired displacement rate. This research is in progress and more results will be available at the time of the conference.
Tensile Properties of Single Flax Fibres (MA37)
Dillon Betts - Dalhousie University, Pedram Sadeghian - Dalhousie University, Amir Fam - Queen's University
The stress-strain response of flax fiber-reinforced polymer (FRP) composites (and other plant-based FRPs) loaded in tension is nonlinear. It has been determined in previous studies that this nonlinear behaviour is not caused by the matrix or specimen shape. Therefore, there is the potential that this nonlinear behaviour is caused by the individual flax fibres. In this study the mechanical behaviour of flax fibres tested under uniaxial tension is examined. A total of 20 flax fibres from two separate sources will be tested and analysed. The first set of fibres were extracted from a manufactured flax fabric from Europe and the second set of flax fibres were provided by a flax farm in Nova Scotia, Canada. The primary objective of these tests is to determine if the mechanical behaviour of the flax fibre is the cause of the nonlinear stress-strain response exhibited by flax fibre-reinforced polymers. A preliminary set of tests showed that the stress-strain response of these fibres is bilinear, but the accuracy of these tests needs improvement. To accurately measure the tensile behaviour of the fibres a 2N load cell was built and programmed. The secondary objective of these tests was to determine the affect of the source of the fibre on the mechanical behaviour. Before testing, each fibre will be examined under a microscope to ensure that the fibres are not damaged prior to testing and to get an accurate measurement of the fibre diameter. This research is in progress and more results will be available at the time of the full paper submission.
Risk-based Wind Design of Tall Mass-timber Buildings (ST76)
Matiyas Bezabeh - The University of British Columbia, Girma Bitsuamlak - Western Univeristy, Solomon Tesfamariam - University of British Columbia
The rapid growth of urban population and the associated environmental concerns are partly influencing city planners and construction stakeholders to consider “Sustainable Urbanization” alternatives. In this regard, recent urban design strategies are entertaining the use of “tall timber buildings”. Generally, tall mass-timber buildings (MTBs) utilize pre-engineered wood panels to form their main gravity and lateral load resisting systems, which makes them lighter and more flexible than buildings made from concrete, masonry or steel. As a result, frequent exposure to excessive wind induced vibrations can cause occupant discomfort and possible inhabitability of the buildings. This paper attempts to apply a risk-based procedure to design a 102 meter tall MTB by adapting and extending the Alan G. Davenport Wind Loading Chain as a probabilistic performance-based wind engineering framework. The structural systems of the study building are composed of Cross Laminated Timber (CLT) shear walls, CLT floors, glulam columns and reinforced-concrete link beams. Initially, aerodynamic wind tunnel tests were carried out at the Boundary Layer Wind Tunnel Laboratory of Western University on the 1:200 scale MTB model to obtain transient wind loads. Subsequently, using the wind tunnel data, the study MTB was structurally designed. In the risk-based performance assessment, uncertainties were incorporated at each step of the Wind Loading Chain, i.e., local wind, exposure, aerodynamics, dynamic effects, and criteria. These uncertainties were explicitly modeled as random variables. Dynamic structural analyses were carried out in the frequency-domain to include the amplification due to the resonance component of the excitation. Structural reliability analysis through Monte Carlo sampling was used to propagate the uncertainties through the Wind Loading Chain to quantify the risk of inhabitability and excessive deflection. The results of reliability analysis were used to develop fragility curves for wind vulnerability estimations. Based on the results, the effects of various uncertainties are discussed, and risk-based design decisions are forwarded.
Developing and Validating Metrics to Evaluate the Occupational Health and Safety Performance of Sustainable Building Projects (GC71)
Orogun Bezalel - University of Manitoba, Mohamed Issa - University of Manitoba
The health and safety performance of sustainable building projects has traditionally been ignored when evaluating the sustainability of these projects in favour of other aspects such as energy, water and indoor environmental quality. This is problematic given that the limited empirical evidence in the literature on that performance unexpectedly showed it can be poorer than that of non-sustainable building projects due to the safety risks associated with sustainable building practices. This reinforces the need to move beyond traditional health and safety performance assessment when assessing it. This paper reports on the methods used to develop and validate a number of health and safety performance metrics to evaluate the performance of sustainable building projects throughout their design and construction. The metrics were categorized per safety maturity driver and developed based on a review of the literature and an identification of the key best practices involved in the management of the health and safety of these projects. The proposed metrics will be validated by industry and academic health and safety experts before actual implementation on select projects. The metrics are expected to help construction organizations assess, benchmark and ultimately improve the health and safety performance of their sustainable building projects. The research is part of an ongoing research initiative led by the Construction Engineering and Management Group at the University of Manitoba and aiming to evaluate the health and safety performance of these projects using leading and lagging indicators
Validating and Weighing the Importance of the Safety Maturity Drivers of the Sustainable Health and Safety Maturity Model (GC72)
Orogun Bezalel - University of Manitoba, Mohamed Issa - University of Manitoba
The health and safety performance of sustainable building projects has traditionally been ignored when evaluating the sustainability of these projects in favour of other aspects such as energy, water and indoor environmental quality. This is problematic given that the limited empirical evidence in the literature on that performance showed it can be poorer than that of non-sustainable building projects due to the safety risks associated with sustainable building practices, thus the need for adequate tools to evaluate it. This paper builds on previous efforts by the Construction Engineering and Management Group at the University of Manitoba to develop the Sustainable Health and Safety Maturity Model. The model reported on in a previous paper aimed to evaluate the maturity of the health and safety practices used on those projects. These practices were categorized into safety maturity drivers reflecting each a main health and safety aspect to evaluate. This paper will focus on describing the methods used to validate these safety maturity drivers and weigh the importance of each. The drivers will be validated by industry and academic health and safety experts using a set of defined criteria before actual implementation of the model on select projects. An analytic hierarchy process will use the same experts to determine the relative weight and thus importance of each driver when evaluating the maturity of sustainable building projects. The model with its safety maturity drivers are expected to help construction organizations assess, benchmark and ultimately improve the maturity of their health and safety practices on their building projects. The research is part of an ongoing initiative aiming to evaluate the health and safety performance of these projects using leading and lagging indicators.
Volatile Fatty Acid production from potato waste using Thermal Hydrolysis Process during mesophilic anaerobic digestion (EN13)
Mohit Bhargav - University of New Brunswick, Kripa Singh - University of New Brunswick
Resource Recovery is an attractive and sustainable waste management approach aimed at maximizing selective extraction of valuable resources from low-value organic waste streams by utilizing the carbon source to produce value-added products. These low-value waste streams (potato waste) pose significant disposal challenges (bulk volume and logistics cost). The most common disposal method is moving these wastes to landfills, which creates several problems such as leachate production and emission of greenhouse gases (methane and carbon dioxide), which are primarily due to the high moisture content and volatile solids present in the waste. Considering the solid nature of this waste, hydrolysis of particulates is a rate-limiting step, which is usually enhanced using several pretreatment methods, especially gelatinization.
This study investigates the effectiveness of pretreatment technology, i.e., Thermal Hydrolysis Process on volatile fatty acids (VFAs) production using mesophilic anaerobic digestion (35oC) in terms of VFA yields, acetic acid yield, and substrate utilization rate. This study will be carried out with mixed culture present in heat treated anaerobic sludge (102oC for 2 hours) and quantitatively establishing operating conditions (Organic Loading Rate [OLR] and Hydraulic Retention Time [HRT]) for desired chemical pathways that are taken by the microbial community to produce these bioproducts.
The process is optimized to produce maximum VFA concentrations (dependent variable) considering potato waste as a feedstock (feed waste COD concentration of 15g/L) at multiple OLRs (6, 9, 12 kg/m3.hr) and 3 different HRTs (0.5, 1, 2 days), keeping pH constant at 7. Potato starch from a local potato processing industry is thermally hydrolyzed in a stirred and externally heated PARR reactor (Series 4650). Experimental results for THP indicate that the operating temperature of 140oC (±3.5%) leads to an increase in soluble COD by 93-96% along with suspended solids reduction of 85% due to solubilization. VFAs and acetic acid yields of 0.5337 (maximum of 0.72) and 0.41 (maximum of 0.49), respectively, can be achieved at an OLR of 6 kg/m3.hr and a HRT of 1 day using respirometric study at mesophilic conditions.
Experimental runs are dedicated to quantifying the independent variables influencing VFA production rates by changing one variable at a time, and evaluating their effects on acetic acid yield. This study will assist in determining the feasibility of pretreatment technology for the production of volatile fatty acids using mesophilic anaerobic digester.
In-situ Removal of Algae and Suspended Solids from a Eutrophic Lake Using Non-woven Geotextiles (EN21)
Dileep Palakkeel Veetil - Concordia University, Catherine Mulligan - Concordia University, Mina Ghasri - Concordia University, Sam Bhat - Titan Environmental Containment
Lake Caron, a shallow eutrophic lake located in Sainte-Anne-des Lacs municipality in Quebec, has been witnessed to algal blooms every summer since 2008. In this trial study, an in-situ floating filtration unit provided with non-woven geotextiles as filter media was tested to treat the water in a small area of the lake enclosed by a floating turbidity curtain. Energy from a solar panel was used to operate the unit. Non-woven geotextiles with different opening sizes were used to capture algae and suspended particles in varying size. Water quality was monitored inside and outside of the turbidity curtain by examining total suspended solids, turbidity, total phosphorus, COD, total nitrogen and nitrate. Chlorophyll a and blue green algae (phycocyanin) concentrations were monitored through out the filtration by deploying a YSI-EXO2 probe. The filters were effective towards algae and suspended particle removals. While the concept of the filtration was proven, some modifications and further experimentation will be needed.
Development of a deterioration model for analysis of unstiffened steel shear walls (ST142)
Armin Farahbakhshtooli - Concordia University, Anjan Bhowmick - Concordia University
Collapse assessment of a structural system under seismic loading requires a reliable analytical model that can accurately capture deterioration in strength and stiffness of the main seismic fuse. Steel infill plates are considered as main ductile fuses of steel plate shear walls (SPSWs). A strength deterioration model is developed for infill plates of unstiffened SPSWs. The model is calibrated against several experimental results. Ductility capacity, post capping ratio, and energy absorbance coefficient are considered as variables in calibration process. Seismic response sensitivity of SPSWs to the variation of these parameters are assessed using two code-designed SPSWs. Eighteen (18) variant models are chosen for each SPSW considering different combination of varying parameters and are subjected to incremental dynamic analysis using a suite of ground motions. Sensitivity of median collapse capacity of SPSW, which is expressed in terms of Sa (T1, 5%), to the selected three parameters (ductility capacity, post capping ratio, and energy absorbance coefficient) are assessed. The results indicate that the capacity of SPSW is more sensitive to ductility capacity change, while the variation of energy absorbance coefficient has a minor effect on total performance of the system.
Seismic collapse analysis of stiffened steel plate shear walls (ST141)
Armin Farahbakhshtooli - Concordia University, Anjan Bhowmick - Concordia University
Steel plate shear walls (SPSWs) are lateral load resisting system consisting of vertical thin steel infill plates connected to the surrounding boundary elements. They are constructed with and without stiffeners. Unlike unstiffened SPSWs limited research is available on stiffened SPSWs. This research work focuses on seismic collapse analysis of stiffened SPSWs. A new constitutive material model to simulate the behavior of stiffened steel plates is developed in this research. The newly developed model takes into account cyclic degradation in strength and stiffness under repeated reversed loading. The accuracy of the developed model is verified against the available experimental results. This paper also compares performances of stiffened and unstiffened steel plate shear walls. A total of four multi-storey SPSWs (3-, 5-, 7-, and 10-storey) are considered with panel aspect ratio of 1.39. Pushover and cyclic analyses are performed on all the SPSW models with and without stiffeners. From the analysis, seismic performance factors, such as response modification coefficient and system overstrength factor, as well as seismic energy absorbance are extracted and compared. The results indicate that stiffened SPSWs can provide higher initial stiffness and higher energy absorbance compare with unstiffened SPSWs. Finally, to evaluate the effects of the stiffeners in the overall performance of the SPSWs, incremental dynamic analyses were performed on all models. Median collapse capacity, which is expressed as Sa (T1, 5%) in this study, is extracted and considered as a benchmark for comparison between stiffened and unstiffened SPSWs.
Structural Performance Analysis and Prediction for In-service Bridge with SHM Data Mining (GC177)
Qiwen Jin - University of British Columbia, Junchi Bin - University of British Columbia, Weixin Ren - Hefei University of Technology, Zheng Liu - University of British Columbia
Structural performance analysis and prediction for the in-service bridge is complicated and challenging, influenced by many unknown and uncertain factors. Many structural health monitoring (SHM) systems have been installed in the large span, dominant, and even small or medium-span bridges recently. A lot of SHM data of structural dynamic and physical response can be collected, and thus the structural performance analysis and prediction can be further improved. This paper firstly analyzes the essential issue of traffic load, bridge structure, and structural response in SHM, such as the two inverse problems. The characters of the bridge SHM data are also pointed out, including the mass data, the variation with different traffic loads and time periods. Then, the distribution function analysis, association analysis, and time series analysis methods are employed to analyze the SHM data, aiming to reflect the structural distribution function, the lateral distribution performance, and the deterioration extent, so as to provide a reference for traffic load management. One case study is also carried out to verify the three methods. The result shows that the SHM data mining methods can be used to analyze the structural distribution function and reflect the lateral distribution performance as well as the deterioration extent to a certain extent.
Improving Resilience of Urban Draining System in Adaptation to Climate Change (Case Study: Northern Tehran, Iran) (EN51)
Negin Binesh - University of Tehran, Mohammad Hossein Niksokhan - University of Tehran, Amin Sarang - University of Tehran, Wolfgang Rauch - University of Innsbruck
Given the adverse impacts of climate change on urban water infrastructures’ resilience, using adaptive strategies is of great importance. For urban drainage systems (UDSs), despite considerable progress in sustainable management of such infrastructures all over the world, they are still exposed to uncertain drivers of future changes. Quantifying the resilience is an important step for long-term increase in resilience of UDSs. In current paper, the resilience of UDS against flooding is conducted through combining hydraulic performance of storm water drainage network with the system performance function. To do this, baseline and future extreme rainfall time series for different return periods were calculated for West Flood-Diversion (WFD) catchment in Tehran, Iran, and then related IDF curves were obtained. Afterwards, hydraulic and hydrodynamic simulation of storm water drainage system was performed for future time under two scenarios: with and without BMPs. This methodology was applied on one flooded node in the network where the amount of system performance and resilience were estimated under extreme rainfall with different return periods. The results showed that adding a vegetative swale to the drainage system would decrease nodal flooding duration and flood volume up to 30% and 35%, respectively. Moreover, resilience against flooding can increase up to 9.12%. Therefore, the existence of low-impact development measures along with traditional urban drainage can be efficient for increasing system sustainability.
Morphodynamic Response of Spencer Creek to Large Precipitation Events and Channel Modifications (EN25)
Emily Martin - Western University, Andrew Binns - University of Quelph
A Plea for Unified Deflection Calculation of Reinforced Concrete Flexural Members (ST11)
Peter Bischoff - Dept. of Civil Engineering, University of New Brunswick
Calculation of deflection for reinforced concrete flexural members is partly empirical in nature and often uses an effective moment of inertia to account for nonlinear behaviour once the member has cracked. In North America, there is presently one approach being used and another being considered for calculation of deflection for steel reinforced concrete, another two for fibre reinforced polymer (FRP) reinforced concrete, and yet another being used in Europe (Eurocode 2). This paper summarizes the different approaches being used to compute deformation, highlights the advantages and disadvantages of each approach, and identifies instances where computed values of deflection may be incorrect. Recommendations are made for a single unified approach able to provide reasonable predictions of deflection regardless of the member (beam, slab or wall) and type (steel and FRP) or strength of reinforcement.
An overview of enzymatic treatment of hazardous pollutants in industrial wastewater using soybean peroxidase (GC128)
Debjani Mukherjee - University of Windsor, Laura Cordova Villegas - University of Windsor, Keith Taylor - University of Windsor, Nihar Biswas - University of Windsor
An enzyme from the soybean seed coat, soybean peroxidase (SBP), which is readily available from the agricultural commodity, can be used to treat toxic aromatic pollutants present in industrial wastewater. In recent years, there has been a demand for innovative, environmentally-friendly wastewater treatment methods to substitute existing technologies. There have been few recent modifications in the physico-chemical and biological processes that are presently used. The drawback of these processes includes: high costs, low efficiency, harsh reaction conditions, high-energy demand and/or formation of hazardous byproducts (Oller et al., 2011). These reasons stimulate the search for alternative methods that are cheaper, faster and easier to maintain. One of the extensively demonstrated alternative methods, enzymatic treatment, combines aspects of both physico-chemical and biological processes since it uses the chemical reaction of a biological catalyst (Steevensz et al., 2014). The process is attractive due to its ease and simplicity of control, short contact time, applicability to biorefractory compounds, no limitations due to shock loading or accumulation of biomass, reduction in sludge quantity and its effectiveness over broad pH, temperature and salinity ranges. This report will summarize the enzyme-catalyzed oxidative polymerization and precipitation/co-precipitation of a selection of toxic compounds that commonly occur in industrial wastewater. The main objective of the research is to determine the technical feasibility of using crude SBP to catalyze the removal of toxic pollutants.
The parameters optimized for all compounds are: pH, H2O2 and enzyme concentrations (latter in U/mL, where U a standard unit of catalytic activity), TOC (total organic carbon) and time dependence to achieve at least 95% removal of the toxic compound. The main instrumentation used are: UV-Vis spectrometer, HPLC (high pressure liquid chromatography), mass spectrometry, TOC analyzer.
Optimization studies aimed for ≥95% removal based on UV-Vis and/or HPLC measurements. Other objectives included: identification of products after treatment in solution and precipitate by HPLC and MS, and total-organic carbon removal. The use of additives such as polyethylene glycol also is discussed. Discussion is extended to cover the use of a pretreatment process, zero-valent iron (Fe°) reduction to reduce the concentrations of SBP and H2O2 required for the enzymatic step, when necessary. In addition, a preliminary cost analysis is carried out for the determination of the economic feasibility of using crude SBP in the treatment of industrial wastewater. The intended audiences for this research are wastewater specialists and environmental engineers.
Enzymatic treatment with soybean peroxidase of an azo-dye, Direct Black 38, and an azo-dye precursor, 4-chloro-o-toluidine (GC127)
Laura Cordova Villegas - University of Windsor, Debjani Mukherjee - University of Windsor, Keith Taylor - University of Windsor, Nihar Biswas - University of Windsor
Aromatic compounds such as anilines and dyes are present in industrial wastewater. Azo-dyes, represented here by Direct Black 38 (DB38), are the major group of dyestuffs used in the textile industry whereas 4-chloro-o-toluidine is used to produce azo dyes in-situ on cotton, silk and as an intermediate in production of Pigment Red 7. This research focused on crude soybean peroxidase (SBP), isolated from soybean seed coats (hulls), which catalyzes the oxidative polymerization of hazardous pollutants in the presence of H2O2. Both compounds are classified as probable human carcinogens by the U.S EPA. The optimum operating conditions investigated were pH, H2O2 concentration and SBP activity (in U/mL; where U is a standard unit of activity unit) required to achieve at least 95% conversion of these pollutants in synthetic wastewaters. For 4-chloro-o-toluidine, the optimum pH for treating 141 ppm (1 mM) of the compound was 4.4. The minimum SBP concentration required to achieve at least 95% conversion was <50 mU/mL and the optimum H2O2 concentration range between 0.5-0.6 mM.
For 391 ppm DB38 (0.5 mM), the optimal conditions to achieve 95% color removal were pH 3.6, 3.0 U/mL SBP and 2.5 mM H2O2, while, also achieving 70% total organic carbon (TOC) removal. To decrease the concentrations of SBP and H2O2 needed, a two-step process was also studied. For this, zero-valent iron (Fe°) reduction was used before SBP treatment. The reduction of the azo-bond with Fe° produced colorless solutions; however the toxic products formed after Fe°, such as aniline and benzidine, should be treated with the SBP for their removal. For DB38, 2g of Fe° for 120 minutes followed by 0.6 U/mL SBP and 1.1 mM H2O2 at pH 5.0 (3 hour reaction) were needed for more than 95% color, dye, aniline and benzidine removal (latter two are 2 of 4 products after Fe°). Use of Fe° allowed the reduction of the required enzyme concentration by 80% and H2O2 concentration by 56% in the enzymatic step compared to a single-step process. Enzymatic treatment was proven to be an effective, simple, environmentally friendly and sustainable alternative to conventional treatment processes for removing toxic aromatic pollutants from wastewaters, whereas Fe° reduction may be a beneficial pre-treatment for azo-dyes: in the present case, Fe° followed by enzymatic treatment, allowed a decrease in the concentrations of SBP and H2O2 needed compared to direct enzymatic treatment. The intended audience for this research is wastewater specialists and environmental engineers.
On the Application of a Generic Numerical Tornado Model to Evaluate Tornadic Wind Loads on Structures (ST75)
Anant Gairola - Western University, Girma Bitsuamlak - Western Univeristy
Realizing the importance of understanding the nature of tornadic loading on structures, several experimental and numerical studies have been conducted to evaluate wind loads due to tornadoes. However, it is a common practice to use geometric dimensions and configuration of physical elements (like guide vane angle, ceiling height, etc.) of an experimental simulator to extract the parameters needed to characterize a tornado-like vortex. This often makes wind load evaluation results very specific to an individual experimental facility (lacking common interpretation) and hinders experimental validation of numerical studies. In this paper, we aim to demonstrate the application of a generic numerical tornado model, that we previously developed, to wind load evaluation and bluff-body aerodynamics.
To validate the numerical tornado model, the results were compared with two independently conducted experiments; (i) interaction of a low swirl ratio tornado-like vortex and high-rise building model, reported in Yang et al. (2011) during an experiment conducted in the Tornado Simulator at Iowa State University, and (ii) interaction of a mid-range swirl ratio tornado-like vortex and mid-rise building model, conducted in an experimental test at WindEEE Dome at Western University. First, numerically obtained results using the generic tornado model were qualitatively compared with the Particle Image Velocimetry (PIV) results reported in Yang et al. (2011). The numerically predicted streamlines and velocity contours around the high-rise building model are observed to agree with PIV measurements from the experimental study. Next, the generic numerical tornado model was used to compute surface pressure coefficients and tornadic wind loads on a 1:200 scale mid-rise building model for various cases of stationary and translating tornado-like vortex. Subsequently, the obtained results were compared with a similar experimental test conducted at the WindEEE Dome. The comparison indicates the significance of vortex wandering in interpreting building surface pressure distribution due to tornado-like vortices and the nature of resulting wind loads. Overall, the study demonstrates the potential of proposed generic numerical tornado model in preliminary wind load estimation and elucidating the underlying aerodynamic interaction between tornado wind field and buildings.
Alteration of wind load on tall buildings due to fluid structure interaction (ST136)
Ahmed Elshaer - Lakehead University, Girma Bitsuamlak - Western Univeristy, Ayman El Ansary - The University of Western Ontario, Sobhy Masoud - Stephenson Engineering Ltd.
Since wind is a governing design load for various structures, an accurate simulation of the aerodynamics will reduce the uncertainty associated with wind load evaluation on structures, and consequently their cost. Thus, highly accurate and reliable computational fluid dynamics (CFD) modelling is required to simulate and evaluate the wind behaviour for wind-induced loads. The state-of-the-art in numerical modelling of the wind-structure interaction of a tall building is usually conducted by simulating structures as rigid bodies, then accounting for the dynamic effect throughout subsequent dynamic analyses. However, this can be considered a rigorous assumption when dealing with flexible structures (e.g. slender tall buildings and long-span bridges), because the structure’s motion may alter the wind flow field leading to changes in the resulting wind loads on the structure. The proper modelling for flexible structures, considering wind-structure interaction, requires the allowance of structures to vibrate within the wind flow that is simulated numerically by CFD analysis, namely “aero-elastic modelling”. The current study uses an equivalent solid model that can simulate the structural behaviour of a detailed skeletal model during wind events. The study also highlights the importance of considering the fluid-structure interaction for tall buildings with high flexibility and demonstrates the possible wind load variation with different flexibility levels.
Sustainable Building Design in Cold Climate Region: A Framework for Residential Building (ST125)
Muna Younis - Western University, Ayman El Ansary - The University of Western Ontario, Girma Bitsuamlak - Western Univeristy
Buildings consume 30% of total energy produced in Canada and contribute up to 12% of CO2 emissions. Hence, the need for sustainable buildings has become more evident to curb the built-environment's environmental foot print through efficient utilization of energy and materials which reduces the negative environmental impact. The aim of this study is to investigate the impact of different building form, orientation, landscaping, shading, and building envelope on energy consumption/cost of a residential building. Building information modeling (BIM) has been utilized using (Revit 2017) and Green Building Studio (GBS) during the sustainable building design process. The study was performed on three different form of low-rise buildings all located in the cold climatic region in Toronto, Canada. Two forms consist of 2-storey low-rise building with different building shape, while the third form was a bungalow. In the first step of the proposed methodology, the forms are investigated to study their energy consumption. Model with the most efficient energy performance has been adopted for further analyses. In the next step, sensitivity analysis is conducted where several test scenarios are simulated to measure the impact of building orientation, shading, windows to wall ratio (WWR), windows type, wall materials, and roof materials on the energy use. Results show that the building envelope had greater impact with energy saving of 45.43%, 19.8%, 13.4%, and 30% were achieved by utilizing WWR 15%, window type “triple glazing low-e”, wall insulation R-value 44, and roof insulation R-value 60, respectively. The best performing orientation led to minimal reduction 2.2% of total lifecycle cost. Likewise, use of shading has reduced the energy by 4.0%. The most efficient energy cost was obtained by an orientation +90° east north of south and WWR of 27%. The total saving in the peak monthly electricity and fuel consumption are 4.1 KW, 39 GJ, respectively. While the saving in net CO2 emission is 10 tons/year and the total reduction in the lifecycle cost is $48,897. It was found that, adopting climate responsive design has shown a significant improvement in the building energy efficiency. Hence, it is vital to be considered at the early stages of the architectural design process to pursuit an efficient utilization of energy.
An Integrated Structural Health Monitoring Tool using Building Information Modeling (ST87)
Ayan Sadhu - Lakehead University, Chanakya Bodupalli - Lakehead University, Ehsan Rezazadeh Azar - Lakehead University
With increasing complexity of modern infrastructure, fast and accurate condition assessment of structures under extreme climatic events has garnered significant attention to the infrastructure owners. Apart from the sudden catastrophic failures, vibration-based structural health monitoring (SHM) techniques ensure occupant safety and its uninterrupted use under varied operational conditions. Sensor-based high quality data collection and subsequent system identification are central to SHM strategies to undertake risk and hazard mitigation in a timely manner. However, just data-driven approaches are not enough to monitor the evolution of damage or any abnormal behavior in a large-scale structure. Recently, Building Information Modeling (BIM) has become a popular as modeling tool for design, production, construction, facility management and life-cycle analysis of newer structures. It is a platform which integrates all the architectural, engineering and construction systems of a structure into one place allowing all the users to incorporate various features effectively and accurately. In this paper, a BIM platform is utilized as an ideal computing environment and digital representation to integrate with structural health monitoring that involves considerable amounts of sensor data and structural health conditions over a longer period of time.
A 3D Revit model of a large-span bridge in Thunder Bay, Ontario is developed to enable automated sensor data inventory into the BIM environment which helps in achieving systematic maintenance and risk management while avoiding manual errors. Such an integrated tool allows users in organizing, processing, and visualizing the sensor data from the monitoring system, updating relevant FE models, and providing valuable feedback for structural retrofitting through a single platform. The data acquisition was performed on three different seasons of the year to check the performance of the structure under varied temperatures and traffic loading conditions. The proposed method is a user friendly and economical framework for condition assessment of large-scale structures.
On the nature of highway litter; a methodology and field study (EN31)
Damien Bolingbroke - University of Regina, Kelvin T. W. Ng - University of Regina, Senthuran Surendran - University of Regina
Solid waste in Canada is generally well managed but litter still exists. Traditional research in this area has focused on the behavioural aspects of littering, the role of litter legislation, as well as the quantification and classification of litter. Saskatchewan has more highways and roads per capita than any other Canadian province and there exists field evidence of highway litter in this province. This led the authors to develop a new waste quantification approach to study highway or roadside litter. An item-oriented litter survey in highway ditches near Regina was conducted to quantify the variations of litter count with respect to the distance from a Statistics Canada defined Census Metropolitan Area (CMA). A trial test was conducted on July 24th, 2017 to develop the quantification framework and to investigate how the length of roadway studied impacts the total litter count. From this trial, an inverse relationship was found to exist between the length of roadway and the litter count density and a 40m length segments were chosen for the full study conducted on August 13th and 14th, 2017. All visible litter of particle size greater than 2.5 cm as well as cigarette butts were collected using a 2m, by ditch width, grid. Results show some evidence to support the hypothesis that increasing distance from a CMA decreased litter count density. The outcomes may lead to future studies in litter data pattern analysis and the use of the methodology presented for further highway or roadside litter studies.
Service Constraints on a Simple GIS Based Curbside Waste Collection Model (EN30)
Hoang Lan Vu - University of Regina, Damien Bolingbroke - University of Regina, Kelvin T. W. Ng - University of Regina
Waste collection expenditure alone made up about 47% of the annual residential waste management budget at City of Regina in 2005. Optimized waste collection routes, such as using Geographic Information System tools, help reduce the waste collection system’s collection time, labour cost, fuel consumption, and environmental footprint. For North American cities and towns with a front-of-street curbside collection program, a bin or collection point is typically serviced on the truck’s passenger side. However, it was found that this service constraint was not explicitly considered in many GIS-based studies. The objectives of this study are to apply the truck’s passenger side constraint and other service constraints to a small study area in Regina, and to investigate their effects on overall travel distance and collection time using different scenarios. A simple GIS-based door-to-door collection model with various service constraints is developed and studied. In some scenarios, the “one-way road” rule is applied in the modeling to force waste collecting vehicles to service the collection points only at the truck’s passenger side. In another scenario, a single collection point is assumed to be shared between two individual waste generation sites to increase efficiency. The results suggested that the model approach with the truck’s passenger side constraint provides more realistic results. In this study, conventional GIS modelling approaches with no service constraints underestimate the travel distance in collection zones by 60.9%. Also, sharing a collection point among waste generators could reduce collection time by at least 12.5% when compared to the status quo.
The economic versatility of self-consolidating concrete – underground and beyond (MA52)
Michael Maher - GolderAssociates Ltd., Grant Bonin - Golder Associates Ltd., Alireza Dehghan - Golder Associates Ltd., Michael Navarra - Golder Associates Ltd.
While originally self-consolidating concrete (SCC) was developed in Japan to address a labour shortage, it is growing in application across North America. The benefits are being recognized mainly in terms of reduced risk to the mechanical and durability properties from improper consolidation. The added product cost can be offset by faster construction, more economical design of reinforcing and concrete section, and reduced construction noise and labour cost. Early in its development, the desired high flowability of SCC was gained by adding excessive amounts of water or superplasticizers to the concrete. Therefore, the mixture had limited application in civil engineering structures when durability requirements were paramount. Establishment of standards and codes of practise for SCC, development of specialized testing equipment, and the introduction of new chemical admixtures, such as high range water reducing (HRWR) and viscosity modifying admixtures, facilitated the production of SCC mixtures with comparable or superior mechanical and durability properties when compared to ordinary Portland cement concrete. Even though SCC has the potential to be used cost-effectively for a broad range of structural concrete, its usage has remained limited mostly to high-end projects. However, this needs to change. This paper will explore some recent project successes where specially formulated SCC mixes were essential components of project feasibility, particularly in underground applications. Some examples are provided of projects where costly remedial measures could have been avoided with the use of SCC. Two case studies are presented that highlight the versatility of SCC and its use in non-conventional underground applications.
Effect of Chopped Basalt Filament Fibre on Modulus of Rupture of Concrete (GC82)
Eric Hughes - University of Windsor, Emad Booya - University of Windsor, Padmanabhan Iyer - University of Windsor, Sara Kenno - MEDA Limited, Sreekanta Das - University of Windsor
Fibre Reinforced Concrete has been gaining popularity and its multiple uses in various constructions such as building pavements, large industrial floors, and runways. A long-term research work is being undertaken at the University of Windsor to investigate applications of chopped filament and other forms of Basalt fibres in concrete. This paper discusses the effect of chopped Basalt filaments fibres on the modulus of rupture when added to fresh concrete. Various aspect ratios and dosages of chopped Basalt filament fibres were added and then the concrete specimens were tested at 28 day to study the effect of these fibres on the concrete’s modulus of rupture. The study found that the optimum length and optimum amount of basalt fibre are 36 mm and 8 kg/m3, respectively if a significant improvement in the modulus of rupture is required.
Assessment of the effect of residual stresses on the mechanical behavior of steel lattice transmission towers (ST55)
Geneviève Gravel - Université de Sherbrooke, Pierre-Luc Bouchard - Hydro-Québec, Simon Prud'homme - Hydro-Québec, Kahina Sad Saoud - Université de Sherbrooke, Sébastien Langlois - Université de Sherbrooke
Power transmission lines predominantly involve lattice towers, which are typically composed of steel angle members connected together by means of bolted joints. An effective design of such structures requires the consideration of a range of complex phenomena likely to affect either the carrying capacity or the failure mode. In practice, simple numerical models are combined with standard design equations to consider these effects. A few advanced numerical models reported in the literature deal with eccentricities, stiffness of the connections, and joint slippage. However, the impact of residual stresses on the global behavior of lattice towers is not addressed in prior works. In this work, the influence of residual stresses is studied numerically using the finite element software Code_Aster. The proposed model employs multi-fiber beam elements to model the elastoplastic angle members, and discrete elements to represent the bolted connections. Both the connection eccentricity and the rotational stiffness of connections are modeled. The associated problem is solved in an incremental way, so as to deal with geometric and material nonlinearities, and the results are compared with experimental tests. Considering residual stresses in advanced models is an important step for the numerical evaluation of the failure of lattice towers.
Utilizing agricultural - wastes to produce green Materials for construction Applications: A review (MA54)
Sara Boudali - Concordia University, Ahmed Soliman - Concordia University, Sébastien Poncet - University of Sherbrooke, Stéphane Godbout - IRDA, Joahnn Palacios - IRDA
High demand of natural resources and the disposal problem of agricultural wastes are two main challenges faced by construction and agriculture sectors. Hence, the use of agro-waste in the construction industry can be an optimum solution. In response to the increased interest in sustainable construction materials, many agricultural waste materials are already used in concrete as replacement alternatives for cement, fine aggregate, coarse aggregate and reinforcing materials. This paper provides an overview for successful implementations of different agricultural wastes to produce green materials for different construction applications. It highlights the quantitative benefits of sustainable construction using agricultural waste materials and benefits of green materials in construction applications. This would allow engineers and policymakers to consider designing for sustainability as a new requirement in the design for publicly funded structures.
Assessment and Renewal of the Centennial Bridge (GC62)
Ashlee Hossack - GEMTEC Consulting Engineers and Scientists, Phil Hamelin - Eastern Designers & Company Limited, Bruce Pond - Eastern Designers & Company Limited, Eric Boudreau - NB Department of Transportation and Infrastructure
The Centennial Bridge, located in Miramichi, NB, was constructed in the 1960s and is currently undergoing major repairs and upgrades to bring the structure up to current standards and prolong its useful life. It is a steel superstructure bridge with tied arch navigation spans, continuous over three spans, flanked by five deck truss spans, twelve plate girder approach spans and one rolled beam span. The Centennial Bridge is a highly-trafficked portion of NB Route 8; therefore, lane closures have to be minimized during construction.
The bridge, which crosses the brackish waters of the Miramichi River, measures 1.1 km in length and includes eight river piers and twelve land-based piers (seven south, five north). Much of the concrete placement for the piers was conducted during the winters of 1964-1965 and 1965-1966 when winter construction practices were far less advanced than modern practice.
The bridge is located in a very demanding environment for construction materials; in addition to the impacts of deicer salts and frequent freezing and thawing periods, the brackish water and tidal impacts affect the concrete river piers. Furthermore, the substructures are difficult to access; therefore, inspection and maintenance activities have been limited. Following the decision to upgrade and refurbish this structure to prolong its useful life, a multi-phase investigation and repair/upgrading program was undertaken.
A thorough investigation of the steel superstructure was undertaken by the structural consultant and upgrades and repairs were conducted in phases commencing in 2013 and concluding in 2017. These activities were planned and scheduled in a manner which permitted traffic to continue with minimal interruption (periodic overnight closures only).
Assessments of the piers were conducted in phases, commencing with the river-based piers in 2013 and 2014 before progressing to the land-based piers in 2016 – 2017. Upgrading and repair of the piers will be completed in a manner which prevents any disruption in bridge traffic. Demolition and concrete placement will be conducted in stages to ensure that the structural integrity of the bridge is not compromised during construction. The first contract (of two) for pier upgrading was awarded recently with construction underway and completion scheduled for the fall of 2018.
The proposed presentation will focus on the condition assessment of the structure; investigation into construction practices utilized during initial construction, and related concerns; consideration of the structure’s environment and future inspection and maintenance requirements; and design for longevity, constructability, and utilization of existing structural components.
Delta-Marriott Hotel Project: A Case Study of Construction Innovations in Building a Hotel Project In Ontario, Canada (GC170)
Sara Rankohi - CANAM, Mario Bourgault - Ecole Polytechnique
The Delta-Marriott Hotel is an 8-storey hotel situated at Prince Arthur’s Landing on Thunder Bay's waterfront, Ontario. The Delta-Marriott Hotel has 150 guest rooms and suites including 18 penthouse suites, with a net floor area of 49,896 sq. ft. The owner, ReSolve Group Inc., awarded CANAM group to supply and erect the project super structure. From construction material employed, design approach, to project coordination, Delta-Marriott Hotel (DMH) is an innovative project. DMH project has an integrated project delivery method in which complete design and drawings were provided along with BuildMasterTM construction service. This project was our first RMR project in which drones were applied to monitor project progress on a daily-basis.
Photogrammetric Modelling of the Grand Falls Hydro Generating Station Tunnel (GC107)
Cody Bradley - University of New Brunswick, Lloyd Waugh - University of New Brunswick, Glendon Hanscom - NB Power
The Grand Falls hydro generating station is located in Grand Falls New Brunswick on the Saint John River. The penstock measures 7.5 m in diameter and travels underneath a portion of the town for approximately 915 m before reaching the turbines. The generating station is typically shutdown once every four years for only a few days to perform visual inspections and maintenance of the penstock. Estimates of the size and location of erosion-induced cavities are documented in reports and spreadsheets, which are then used to plan and prioritize maintenance. Interpreting inspections in preparation for maintenance is challenging given the size of the penstock, the subjectivity and selectiveness of the inspections, and the difficulty in linking the spatial evolution of erosion between subsequent inspections.
A photogrammetric modelling workflow was developed to generate and distribute accurate high resolution 3D visual and spatial models of the tunnel. The literature was reviewed to assess potential data acquisition technologies. Chief candidates included photogrammetry, as well mobile and stationary LiDAR systems. Photogrammetry was selected based on the provision of accurate spatial and high resolution visual data. A semi-automated photogrammetric data acquisition system incorporating micro controllers and wireless technology was designed and fabricated to facilitate data capture. Approximately 5000 images were taken of the 822 m concrete lined section of the Grand Falls tunnel during a two week scheduled shut down for maintenance and repairs. The images were processed and combined with traditional surveying to generate accurate high resolution visual and spatial models. Traditional survey check points suggest the accuracy of the spatial model is in the order of 5 mm. The resulting models will be delivered in a virtual reality interface that is currently under development and will provide users with a thorough and objective view of the tunnel’s condition. The objective of the interface is to facilitate navigation, visualization, and easy access to the models. The Grand Falls tunnel models will provide valuable information for future engineering assessments, job planning, contracting, repairs, scheduling and the location of potential future development of hydro in Grand Falls.
Shear Behaviour of Cast-in-place Anchors at Low and High Strain Rates (GC15)
Lenda T. Ahmed - Carleton University, Abass Braimah - Carleton University
The use of anchorage to concrete systems in construction is on the rise. Moreover, the anchorage to concrete systems are subjected to various loading conditions; including static, dynamic and shock. However, limited information is available on the behaviour of anchorage to concrete systems under impact and high strain rate loading. This paper presents the shear behaviour of cast-in-place anchorage to concrete systems using finite element analysis. Cast-in-place anchors were embedded in concrete with compressive strengths of 20 MPa, 30 MPa and 40 MPa were investigated at static (10-5 s-1) and high strain rate (103 s-1). The anchorage systems used two anchor diameters (12.7 mm and 19.1 mm) and two embedment depths (76.2 mm and 152.4 mm). The analyses results show that the ultimate shear load increased with the strain rate for the same concrete compressive strength. The increase in compressive strength led to increase in the ultimate shear load for the anchors tested when pryout failure mode was the dominant failure mode. A maximum ultimate shear load increase of 40.8% was achieved for concrete compressive strength increase from 20 MPa to 40 MPa at strain rate of 10-5 s-1. At high strain rate of 103 s-1 maximum increase in the ultimate shear load of 2.7% was obtained for concrete compressive strength increase from 20 MPa to 40 MPa. Increase in the anchor diameter and embedment depth was also observed to increase the ultimate shear load. As well, the anchorage to concrete system failure mode was influenced by increase in strain rate while the increase in concrete compressive strength from 20 MPa to 40 MPa had no effect on the failure mode at high strain rate where steel failure is observed.
Contact Explosion Response of Reinforced Concrete Columns: Experimental and Validation of Numerical Model (DM13)
Alok Dua - Carleton University, Ottawa, Abass Braimah - Carleton University, Manish Kumar - Indian Institute of Technology Bombay (IITB)
Protective design of critical infrastructure and iconic buildings and monuments against terrorist attacks requires the incorporation of blast-resistant design to ensure adequate safety against explosive threats in today’s environment. Consequently, the response analysis of structures subjected to blast loading has gained importance with structural engineers in the recent years. Past research efforts have mostly focussed on the far-field blast response of structural components with limited emphasis on the near-field and contact explosion response. Thus, there is a lack of knowledge on the response of structural components to the effects of near-field and contact explosion. The behavior of reinforced concrete components have been studied numerically however there is limited experimental data for validation of these numerical models. The experimental data is scarcest in case of concrete columns. Columns are the most vulnerable and critical member in any structure and are prone to contact explosion attacks using small quantities of explosives. This paper presents a benchmark study for the response of full scale reinforced concrete columns with pad footing when subjected to contact explosions of varying charge mass. The quantitative and qualitative assessments of damage to concrete columns, including spalling and scabbing are presented. The experimental data was used to validate a set of numerical models in LS-DYNA. These models were used in further parametric studies to establish the effects of various design parameters on the response of concrete columns to contact explosions. Preliminary results of the parametric studies show that the response of the concrete columns subject to contact explosion can be reliably predicted using the validated numerical models.
Monitoring of scour hole development at a control structure in the estuary of the Petitcodiac River at Moncton, NB (GC73)
Dale Bray - Retired, Daryl Demerchant - GEMTEC Ltd.
In 1968, a control structure became operational as a component of a causeway at Moncton, NB on the estuary of the Petitcodiac River. The control structure was originally designed to allow water to flow from the land upstream to the estuary downstream. The clear opening at the control structure is 44.2 m in width and 6.1 m in height. The sill elevation of the control structure is -1.5 m. The structure and the approach channels were built on fractured mudstone. On April 14, 2010, the gates at the control structure were opened to enhance the passage of fish through the structue. In anticipation of the gate opening, a program involving detailed hydrographic surveys was initiated a few days before the gates were opened to assess the development of a scour hole on the upstream side of the structure. In November 2011 surveys were extened to the downstream side of the structure. With all gates opened at the control structure, the estimated peak flow for an average high tide of elevation 6.1 m is about 1500 m3/s. The 100-year flood flow from the land at the control structure is estimated to be about 1000 m3/s. With the gates opened the tidal flows usually exceed the magnitude of the 100-year flood flow twice a day. In June 2015, the maximum depth of scour near the control structure was 4.5 m below the sill on the upstrream side and 7.3 m below the sill on the downstream side. The paper describes the methods adopted for the surveys and presents the temporal and spatal development of the scour holes.
An historical account of the 'William L. Barrett Water Treatment Plant' in Fredericton, NB (GC13)
Dale Bray - Retired, Laurie Corbett - Retired
Motivated by generations of destructive fires and outbreaks of thyphoid fever, the municipality of Fredericton, having a population of approximately 6000, began a water supply system with the construction of a water pumping station in 1883. The plant was designed to supply 400,000 Imp. gallons/day (1820 m3/d) at a pressure of 35 psi (241 kPa). This became the core of a growing structure to house a water supply and water treatment system and related technologival advancements. The original construction provided a solid masonry building and chimney to house steam boilers and a pump to provide a supply of water from the St. John River. Improvements in 1906 included a building extension, plumbing, pumping, coagulation basins, and storage basins for a rapid-sand filtration system. At the time this advancement was considered to be the most complete filtration plant for a municipal water supply in Canada. In 1912, the structure housed one of the earliest continuous chlorination systems of a public warter supply system on the continent. The arrival of electricity in 1926 allowed a partial conversion from steam technology, and required a large addition for a 125 kVA diesel generator. The building was repurposed in the 1950s to pump water from groundwater wells. In 1984, the facility was re-engineered and expanded to provide for the removal of manganese from groundwater using pressurized filtration. At that time the manganese removal system was the largest of its kind in North America. The facility which began in 1883 was renamed the William L. Barrett Water Treatment Plant in June 2007. The current water treatment plant uses contemporary treatment processes while retaining and repurposing the historic components of the structrue. The facility has been accepted as a CSCE National Historic Civil Engineering Site in 2018. The paper documents the key features of the William L. Barrett Water Treatment Plant from 1883 to present.
Monitoring of physical changes associated with the restoration of the tidal prism in the estuary of the Petitcodiac River, NB (GC81)
Daryl Demerchant - GEMTEC Ltd., Dale Bray - Retired, Michael Pauley - New Brunswick Department of Transportation and Infrastructure, Andrew DeMerchant - GEMTEC Consulting Engineers and Scientists Limited
In 1968, a tidal barrier was constructed in the estuary of the Petitcodiac River between Moncton and Riverview, NB. The purpose of the barrier was to provide a highway crossing and to protect up-river farmlands from salt water flooding. The barrier cut-off about 24 km of river subjected to tidal flooding. The associated tidal prism had a volume of about 27 million m3. The estuary is characterized by its high tidal range in the order of 12 m at its lower end and its high concentration of suspended solids in the order of 25,000 mg/L near the barrier. Following construction, siltation occurred in the 37.3 km of river below the barrier, reaching a magnitude of about 161 million m3 in 2001. On April 14, 2010, the gates in the tidal barrier were opened and the tidal prism upstream of the barrier was partially restored. This paper details the changes in physical properties of the river over the period 2010 to 2015 as a result of opening the gates. In particular, new tidal flats consisting of about 7 million m3 have formed upstream of the barrier and about 50 million m3 of erosion has occurred downstream. Most of the downsteam deposition occurred in the upper reaches of Shepody Bay located 37 to 50 km downstream of the tidal barrier.
Identifying the Factors that Increase the Severity of Pedestrians' Injuries when Struck by Vehicles (TR33)
Essam Dabbour - Abu Dhabi University, Spencer Bridgwater - Ryerson University, Murtaza Haider - Ryerson University
Over 280,000 pedestrians die every year globally in collisions with motorized vehicles. In the United States, a substantial 26% decline in overall highway fatalities between 2005 and 2011 has been recorded. However, pedestrian fatalities have increased during the same period. Thus, pedestrian fatalities as a proportion of overall fatalities in road collisions has increased from 11% in the early 2000’s to approximately 14% in 2011. This paper analyzes the factors affecting the severity of pedestrians’ injuries when struck by motorized vehicles. Using ordinal regression models, the paper analyzes the severity of pedestrians’ injuries in pedestrian-vehicle collisions that occurred in Washington State from January 1, 2004 to December 31, 2013. The paper evaluates several risk factors including those related to the time of the collision (the time of the day, the day of the week, and the season of the year), location of the collision (mid-block vs. intersection, urban vs. rural, divided roadway vs. undivided roadway, two-lane roadway vs. multi-lane roadway, signalized intersection vs. unsignalized intersection), vehicle characteristics that struck the pedestrian (type and age of the vehicle), environmental conditions (weather, lighting, and road surface conditions), and finally pedestrian and driver attributes (age, gender, impairment condition). Identification of the most significant factors that increase the severity of pedestrians’ injuries can help engineers and decision makers to adopt adequate measures to improve pedestrian safety. Furthermore, ordinal regression models also provide up-to-date quantification of the level of significance of the identified factors.
Applying Ethics in your Civil Engineering Career (GC89)
Peter Wu - Reinforced Earth Company Ltd., William Brockbank - Reinforced Earth Company Ltd.
Ethics in Engineering
Graduating engineers in this country are quickly introduced to what is referred to as the Engineer’s Code of Ethics. The document is a quick guideline of how we must conduct ourselves as engineers in our professional life. Most engineers you speak to will not be able to recite the entire document but generally can recall the opening statement “that an Engineer shall treat public safety as paramount”.
To help solidify the concepts presented in the Code of Ethics we are mandated to read a book on
Engineering Ethics and to write a three hour exam on Professional Practice and Engineering Law. Upon successful completion of this process, a minimum of 4 years work (previously 2 years), we are granted our professional status and allowed to practice the profession of engineering. Although there are several examples in the text book of how an engineer may be conflicted on this issue during his professional career, the real challenge does not start until the engineer begins his professional work.
Whether the engineer fills a position with his employer of designer, manager, or executive he will be charged to play a role in the companies mandate to be profitable, and so begins the balancing act of trying to fulfil the two directives at the same time, a task which is often, wrought with conflicts.
With the current trend in Canada’s new infrastructure construction projects to utilize the project delivery methods of Design Build and P3, the engineer finds himself in an even greater challenge for the balance of quality and cost. Concepts of prudency and redundancy which were upheld as noble attributes in the past, are being replaced in today’s market by a focus on cost cutting and low bid mentalities.
This paper will examine some of the typical situations where engineers find themselves to be challenged on this issue and provide some suggestions the authors have found useful in their career.
Comparison of Canadian Seismic Design Provisions for Tall Braced Steel Frames in Heavy Industrial Applications (ST59)
Frédéric Brunet , Tremblay Robert - Polytechnique Montreal
Steel structures used in large industrial facilities in the mining, oil and chemical sectors must be designed to withstand heavy production loads. Furthermore, the process generally governs the structural configuration, which often results in tall buildings with significant geometric and/or mass irregularities. In 2014, Annex M: Seismic Design of Industrial Steel Structures was created and incorporated into the CSA S16-14 standard with the aim of providing guidelines for the seismic design of heavy industrial structures. For moderate and high seismic zones, the Annex allows steel concentrically braced frames (CBFs) of the moderately ductile (Type MD) category to be used for structures up to 60 m tall but the design seismic loads must be increased by 1.3 for frames above 40 m to compensate for the lack of redundancy of the system. Alternatively, tall braced frames may be considered as of the Conventional Construction (Type CC) category for design. In this case, simpler design rules apply but this is at the expense of design seismic loads approximately two times higher due to the limited ductility of the system. In addition, seismic induced forces in columns must be further amplified by 1.3 to provide for higher protection and the frame height is limited to 40 m in high seismic regions. The purpose of this research is to explore the possibility of relaxing current CSA S16 height limits and special design requirements for columns of tall CBFs used in heavy industrial applications. A prototype industrial structure 65.4 m tall and located in Vancouver is used to compare design seismic loads and steel tonnage for the two CSA S16 design strategies. A third approach is also used where the frame is designed as a Type MD system without the 1.3 amplification specified in Annex M. The results show that Annex M leads to heavier and thus less economical structure. Nonlinear response history analyses were carried out with the OpenSees program to examine the brace yielding and buckling scenarios over the frame height and the resulting column axial load demands. Storey drifts and flexural demands on columns are also studied. For such a tall frame, brace inelastic response does not develop simultaneously over the entire structure height, as currently assumed in design, suggesting that column design provisions could be relaxed.
Landslide generated tsunamis: New laboratory experiments and theoretical developments (DM30)
Ryan Mulligan - Queen's University, W. Andy Take - GeoEngineering Centre at Queen’s – RMC, Department of Civil Engineering, Queen’s University, Gemma Bullard - Queen's University
Landslide generated tsunamis are major hazards on mountainous coasts that can cause natural disasters due to vast inundation of coastal communities. To investigate the complex process of tsunami generation by landslides, experimental observations are obtained by releasing material and capturing the wave behavior with high speed digital cameras and wave probes in a large laboratory landslide flume. These detailed observations are used to validate a new expression that describes the wave amplitude in the near-field zone. The theoretical relationship that governs the maximum wave amplitude is derived by considering the transfer of momentum from the sliding mass to the water. This work provides a new method for predicting the landslide wave amplitude that is easily applied in practice. The results can be used in the near-field evaluation of tsunamis or to define boundary conditions for numerical models to determine the extent of wave propagation and run-up from these major coastal geo-hazards.
Shear Capacity Prediction of Precast/Prestressed Hollowcore Slabs (ST33)
Robert Burak - Canadian Precast/Prestressed Concrete Institute (CPCI), Karl Truderung - Tower Engineering, Ehab El-Salakawy - University of Manitoba
Precast prestressed concrete hollowcore slabs are an economical system for a floor or roof, where uniform load conditions coupled with large spans dictate the design. However, design provisions used for evaluation of shear capacity of precast prestressed members vary depending on the design code used. It is believed that the current North American concrete design codes may result in unduly conservative shear designs for precast/prestressed hollowcore slabs. Research was conducted to compare the shear capacity predictions of hollowcore slabs with laboratory testing, using the Canadian, American and European codes, to evaluate the accuracy of code predictions. A testing program was undertaken on a total of twenty-four full-scale hollowcore slabs in the 203 mm (8-inch) to 305 mm (12-inch) depth range, from two hollowcore manufacturers, using two types of extrusion machines. The test apparatus for the hollowcore slab specimens used the standardized hollowcore shear test in the European code. This paper focusses on the results of the twenty-four test slabs. The test variables included the length of bearing, the level of prestressing, and the slab depth. Results are presented in terms of predicted capacities and modes of failure. The test results are compared with the predicted shear capacities according to the European, Canadian and American codes. The mechanics of the shear design equations of each code are reviewed, including the effect on shear capacity of horizontal shear stresses within the transfer zone, a design requirement of the European code that is not currently included in the Canadian or American code equations for evaluation of shear capacity.
Seismic response sensitivity of controlled rocking steel braced frames (ST4)
Saber Moradi - Ryerson University, Henry V. Burton - University of California Los Angeles
Controlled rocking steel braced frames have been demonstrated recently as self-centering systems that can reduce permanent deformation of structural members in a major earthquake and thus minimizing repair costs. The design of these frames allow for rocking action at the base of columns. The overturning resistance is provided by the gravity loads and post-tensioned high-strength steel strands, while energy dissipation is primarily provided by easily replaceable steel plate fuses. In this paper, the sensitivity of seismic response of controlled rocking steel braced frames is investigated with respect to design parameters, including the yield strength, initial lateral stiffness, and strain hardening ratio of the fuse, the initial post-tensioning force and modulus of elasticity of the strands, as well as the rocking column gravity load. In addition, the effects of frame aspect ratio and earthquake intensity level are assessed. The study is based on conducting nonlinear response history analysis of controlled rocking steel braced frames as well as utilizing the design of experiment method for effective and reliable sensitivity analyses. Based on the results, the peak roof drift response is dominated by the effects of initial post-tensioning strand force and rocking column gravity load, while the residual roof drift and peak floor acceleration are influenced by several factors and interactions.
Unsaturated Polyester (UP) Resin Mixed with Aggregates as the Surface Course for Permeable Pavements (MA79)
Jia-Ruey Chang - National Ilan University, Song-Jun Wang - National Ilan University, Yi-Ting Luo - National Ilan University
In this study, unsaturated polyester (UP) resin was used as the adhesive material for blending with alabaster or natural aggregate at ambient temperature for the surface course on pavements. UP resin is non-toxic and has good weather resistance. It is a good material for replacing the commonly seen epoxy resin. The mixture after blending UP resin with alabaster or natural aggregates has a very high strength and its stability can reach two to three times of that of asphalt mixture within a few hours. Moreover, the mixture’s coefficient of permeability is nearly 40 times higher than that of porous asphalt mixture. In this study, the effects of temperature and water content of aggregates on the hardening of UP resin mixture were studied. We found that different additions of accelerator and hardener were required at different temperatures to adjust the hardening time of mixture. Higher additions resulted in faster hardening rate, but adding an excessive amount reduced the final strength of the mixture instead because of the residues of the accelerator and hardener. The water content of aggregates caused the hardening reaction to be sluggish and incomplete. Only 1% of water content in aggregates substantially slowed down the hardening. Conditions at higher temperatures reduced the effect of water on hardening.
Impact of climate variability on flow and sediment transport of the Magdalena River through the analysis of historical series (DM5)
Fabian Andres Yara Amaya - Universidad Nacional de Colombia Sede Manizales, Maria Alejandra Osorio Castro - Universidad Nacional de Colombia Sede Manizales, Jorge Julián Vélez Upegui - Universidad Nacional de Colombia Sede Manizales, Philippe Chang - Universidad Nacional de Colombia Sede Manizales
Interface Planes for Discharge Estimation in Non-symmetrical Rectangular Compound Channel (GC80)
Jean George Chatila - Lebanese American University
The complexity of flow area determination in compound channels may lead to errors in flow estimation. Although the uniform flow formulae, such as Manning’s equation, are widely used to determine flows through open channels having simple cross-sections, this may lead to considerable errors in the case of compound channels. This paper evaluates alternatives to account for flood plain conveyance in non-symmetrical rectangular compound channel flows by determining the best interface plane arrangement leading to flow estimation for different flow depths. Evaluations are based on applying several traditional discharge estimation methods to a laboratory data set in a non-symmetrical rectangular compound channel cross-section. Five interface and two other standard methods for computing discharge in open channels were compared. Each interface method uses a particular arrangement of imaginary interface planes to artificially sub-divide the compound flow field into homogeneous zones. These methods are named for the particular interface plane arrangement adopted. The two standard methods do not involve interface planes. Computed discharges were compared and evaluated by applying various statistical measures to determine the degree of goodness-of-fit between computed and observed discharges. In terms of overall performance, the inward diagonal interface plane method produced the most accurate computations among the methods tested for the non-symmetrical compound channel cross-section under consideration.
Keywords: Compound channels, interface planes, discharge estimation, goodness-of-fit, non-symmetrical, open channel, Manning’s equation.
The Influence of Asphalt Rheological Behavior and Durability of Recycled Asphalt Concrete under High Viscosity RAP and High Addition (MA78)
Shih-Huang Chen - National Central University
This study performs laboratory investigation to discover the rejuvenating effect of Rejuvenating Agent (RA) on the performance of aged asphalt binder and asphalt concrete in order to increase Recycled Asphalt Pavement (RAP) usage. It distinguishes between asphalt binder employing viscosity blending chart from AI MS-2, and penetration grade from Japanese blending chart, to find optimum necessary RA in the blends and solve the rutting problem. The material used was 20% and 40% of a 10,000 poises Recycled Asphalt Binder (RAB) with AC 20 as virgin binder and RA. Original condition, short-term aging, and long-term aging samples were used to describe the durability of the mixtures. Penetration blends decreased the RA needed about 40% compared to the viscosity blends and showed better rutting performance, especially for a higher percentage of RAP. Viscosity blending yielded a misleading in the addition of RA and resulted in softer RAB, which is susceptible to rutting. Thus, for the case of rejuvenating severely aged and quite high content of RAP mixtures, relying on only viscosity test and AI MS-2 is not adequate.
Data Envelopment Analysis (DEA) for safety-based efficiency evaluation of construction sites (GC145)
Mohammad Nahangi - University of Toronto, Brenda McCabe - University of Toronto, Yuting Chen - University of Toronto
Identifying efficient construction sites in terms of safety is a challenge that must be addressed while assessing and evaluating performance criteria. This paper presents a method for comparative and relative analysis of construction sites in terms of their safety performance. The proposed method employs Data Envelopment Analysis (DEA) for identifying efficiency of construction sites, also known as decision making units (DMU’s). Safety climate factor and number of incidents are respectively used as inputs and output of the DEA system. Four various scenarios are performed and analyzed, and results are compared to evaluate efficient construction sites. Results show that the number of incidents incurred at construction sites, which is the output of the DEA framework, is the dominant factor correlating with the efficiency of construction sites. Moreover, specific safety climate factors are investigated to examine their impact on the efficiency calculated. Some other important observations that all comply with practical expectations are also reported.
Resilience of Glulam Timber Beams after Fire Exposure (ST80)
Bronwyn Chorlton - Carleton University, Georgette Harun - Carleton University, John Gales - York University, Elizabeth Weckman - University of Waterloo, Matthew Smith - Entuitive
Engineered timber relies on complicated adhesives to join wood elements and build up large section sizes. In Canada, the latest tall timber structure using this material is the Brock Commons building, an 18-storey residence building in British Columbia. In Europe, the 21-storey Haut building is being planned. Both buildings see the clash between architecture and fire safety. On the one hand, the designer wants to build with a maximum amount of exposed timber but to do so requires a rational understanding by both designers and authorities of the performance of engineered timber in and after fire.
The response of engineered timber to fire exposure primarily involves charring and adhesive degradation. Current allowances for the effective cross sectional area of fire-damaged timber are determined by assuming a zero strength layer beyond the char zone. Use of this analysis technique is meant to implicitly account for degradation effects that include the break down of adhesive. Understanding the severity and consequences of this degradation can be used to better determine performance engineered timber under fire exposure, thereby beginning to determine the level of reparability that would be required after a fire. Knowledge of the level of reparability influences if, and how long, a building would be out of service after a fire – essentially its operational resilience.
The research herein examines the fire performance of twelve 4.2m long engineered timber glulam beams burned using local heating on controlled locations along their length. Beams which had the fire concentrated to their middle third, theoretically experienced a large moment when they were loaded under two-point loading. Beams that had the fire concentrated to the side theoretically experienced a large amount of shear under this same setup. The char depth of the beams has been measured, and an anticipated strength for the loading conditions calculated using the allowances for the effective cross sectional area. The actual strength has been compared to the prediction, and an alternative allowance for calculating the effective cross sectional area is provided. The current allowances for determining the zero-strength layer may underestimate the amount of strength the beams have lost, and the effects of degradation are more severe than anticipated.
The results can be used to understand the performance of glulam beams during and after a fire, and consequently to determine the operational resilience of a building. The results will provide the practitioner new indications of the feasibility of leaving the beams exposed.
Vehicle Routing Problems: True Optimal Solutions (TR5)
James Christie - University of New Brunswick
The efficient and effective utilization of both the transportation vehicles and the transportation infrastructure are critical to the continuing sustainability of the vehicular and infrastructure systems. Optimizing vehicular use of the transportation infrastructure results in a number of benefits for private transport companies, public departments of transportation infrastructure, and the general traveling public, among them being reduced operating costs, reduced energy use, decreased pollution, reduced demand for resources in terms of vehicles and infrastructure, improved safety in terms of saved lives and fewer injuries, improved level of service and extended economic life for the existing infrastructure. Transportation engineers have been challenged for decades with finding a true optimal solution, although a number of approximate heuristic methods have been applied with some success. Developing a methodology to find the true optimal solution to the vehicle routing problem is the first step. This has been the primary goal of this research.
The focus has been on an exact solution to the point-to-point vehicle routing problem using a combination of linear and constraint programming methods. In the simplest situation this means that a single vehicle is used to deliver (or pick-up) goods to (or from) a number of customers that are located throughout a service area; the objective is to leave the depot and service each customer using the most efficient (least time, distance or cost) route from customer to customer and finally returning back to the depot – thus defining the traveling salesperson problem. If the capacity of the single vehicle is exceeded then more vehicles have to be sent out, and the traveling salesperson problem has to be solved for each vehicle such that the total customer base is serviced most efficiently with the least number of vehicles. The problem was approached in two phases : finding, firstly, an efficient and effective integer linear programming, with appropriate constraints, exact solution to the traveling salesperson problem; secondly, to then incorporate this procedure into finding an exact optimum solution to the more general point-to-point vehicle routing problem.
Both phases have been successfully completed with initial testing on various sized problems with a maximum of 50 nodes to this point. An original and novel way to merge integer linear programming and constraint programming has been developed that is both efficient and effective in solving the vehicle routing problem in a reasonable, acceptable amount of time.
Improved Fastener Design for NLT Bridge Decks (ST120)
Wanrong Zhu - University of New Brunswick, Meng Gong - University of New Brunswick, Ying Hei Chui - University of Alberta, Ling Li - Wood Science and Technology Centre
Timber bridge decks are in great demand in New Brunswick, Canada. According to New Brunswick’s Department of Transportation Institute (DTI)’s reports, there are 32 types of different bridge substructures supporting more than 700 bridges with timber decks in the province. The timber bridge deck currently used in New Brunswick is mainly nail-laminated timber deck (NLT). Based on DTI’s experience, with their current nailing method, the nail-laminated timber decks that are fabricated in New Brunswick have to be replaced every 10-15 years. Obviously, it is a costly practice for maintenance and replacement considering the number of bridges with timber decks as well as their current service life span.
This study was aimed at developing a suitable type of mechanically laminated timber bridge decks that could obtain high stiffness and prolonged life span. This could be fulfilled in terms of developing an improved fastening designs by considering the parameters such as fastener type, fastener diameter, and fastening design. In this study, the parameters taken into account include two fastener types (i.e. nails and screws), two diameters of each fastener type (i.e. two nails diameters and two screws diameters), and two fastening directions (i.e. parallel fastening, 45-degree fastening). Double-shear-nail tests were conducted via a universal electromechanical testing machine in accordance with ASTM D1761 Standard. The stiffness, peak load, and energy dissipation of each fastening design were calculated and analysed.
KEYWORDS: Bridge deck; fastener-laminated timber, fastening design; double-shear-nail mechanical test; stiffness; energy dissipation; peak load
Reducing Cement Usage of Florida Structural Concrete by Optimizing Aggregate Gradation (MA76)
Hung-Wen Chung - Univeristy of Florida, Thanachart Subgranon - University of Florida, Yang Chun-Hao - University of Florida, Mang Tia - University of Florida
The concrete industry in Florida is presently facing two major challenges, namely (1) the rising cost of cement and (2) the shortage of fly ash. The ascending price of cement has increased by 17.8% from 2012 to 2015. According to the forecast of fly ash utilization from American Road and Transportation Builders Association in 2015, the demand for fly ash will increase by at least 53% for the next 20 years. One of the possible solutions to these challenges is through a more effective design of concrete mixes for which the cementitious materials contents have been minimized.
Preliminary investigations have indicated that most FDOT concrete mixes have an excess of paste. The main reason for this is due to the mistaken assumption that concrete can always be made stronger and with quicker strength gain by increasing the content of cementitious material. In reality, 10 to 20% of the cement content in most FDOT concrete mixes can be removed without any adverse effects on the plastic or hardened concrete properties. This reduction in cement content can be maximized by using an intermediate-sized coarse aggregate along with the original aggregate (for example, using standard #57 graded coarse aggregate with #89 graded coarse aggregate). By adjusting the gradation of the coarse aggregate blend, an optimum packing of aggregate (optimum aggregate gradation, OAG) can be obtained such that the aggregate volume content is maximized. The use of OAG along with the reduction of paste (cement) content can improve the properties of the concrete mix, including (1) improved workability of fresh concrete, (2) reduced shrinkage, (3) increased resistance to intrusion of deleterious chlorides and sulfates, and (4) reduced heat of hydration. Also, the reduction in the use of cementitious materials would significantly reduce the cost of concrete, and reduce the environmental impact by conserving natural resources, lowering energy consumption, and lowering carbon dioxide emission. According the results, reducing cement usage of concrete by OAG method is an approach to improve Florida structural concrete.
Structural Management of an Aging Concrete Box Girder Viaduct on the Auckland Motorway Network (GC24)
Liam Coleman - Opus International Consultants, Johan Klopper - Opus International Consultants, Alyson Dean - WSP / Opus
Victoria Park Viaduct (VPV) is a vital link on the Auckland Motorway network, carrying more than 100,000 vehicles daily. Constructed in 1964, the viaduct is comprised of twin parallel bridges each consisting of 24 prestressed concrete spans and 9 semi-continuous cast-in-situ box girder spans. In the 1980s, widespread Alkali-Silica Reaction cracking on the box girder sections was noted, which led to a suite of Carbon Reinforced Polymer strengthening to increase the deck capacity. In 2013, High Productivity Motor Vehicles (HPMVs) were introduced to the New Zealand State Highway network to improve freight movement countrywide. The introduction of these vehicles highlighted the structural deficiency of VPV based on traditional assessment techniques. In addition, the local regional network authority has had aspirations of allowing heavy-axle double-deck buses across the structure, which have been restricted as a result of previous assessments. VPV forms a critical link in the central motorway junction of Auckland and needs to continue to function well into the future. WSP/Opus has developed a strategy to better understand the structure, looking at avenues to more accurately determine its capacity in order to assess it for HPMV loading. This involved building a Finite Element Analysis model, live load testing, deflection monitoring, and detailed site inspections to understand the behaviour and conditional aspects of the asset. As a result, it was demonstrated that VPV can be opened up to greater freight and public transport requirements, serving tomorrow’s society well into the future.
Performance Based Seismic Design in Reinforced Concrete Tall Buildings in Indonesia (ST95)
Sugeng Wijanto - PT. Gistama Intisemesta, Nelson M. Angel - IDEAS S.A.S., Bogotá, Colombia, José Restrepo - University of California at San Diego, Joel Conte - University of California at San Diego
Rapid development of tall building construction has been taken place over the last decade in Indonesia, especially in its capital, Jakarta. Reinforced concrete has been the preferred material of choice used for these buildings because it is economical and is easily handled by local contractors. Along with this rapid development, the Indonesian codes for structural design practices have experienced major changes, following the latest development of USA building design codes and performance-based design guidelines, especially those related to seismic design.
This paper describes the latest seismic code in Indonesia and presents the state-of-the-practice for the design of tall buildings there. It also discusses the use of performance-based seismic design as an alternative method of design, considering the risk targeted maximum and service earthquakes, in the structural design of a 55 story residential tower in Jakarta.
Optimization of Steel Unbraced Frame Systems in Multi-storey Buildings (ST45)
Gérard Poitras - Université de Moncton, Christian Kenny - Université de Moncton, Gabriel Cormier - Université de Moncton
A Particle Swarm Optimization algorithm (PSO) was used to find the optimal design of unbraced frame configuration systems in multi-storey buildings. The unbraced frames were optimized by minimizing the weight of their members while respecting the design requirements of the National Building Code of Canada (NBC 2010) and the Canadian standard for the Design of Steel Structures (CAN/CSA S16-09). The algorithm finds the optimal member sizes of the lateral force resisting system of a rectangular building consisting of four unbraced frames. Since a symmetrical rectangular building is implied, only two distinct frames are optimized, perpendicular to one another. The frames with the smallest weight are found by selecting appropriate sections from a commercially available set of wide flange steel sections. The algorithm accounts for the serviceability and strength constraints as specified in CSA S16. Two major changes to the standard PSO were used in this study. During the iteration process, a fly-back method was implemented for members that do not meet all design criteria. Furthermore, the particle velocity of the PSO is limited to a minimum value to avoid premature stagnation of the solution. This prevents the PSO from being stuck in a non-optimal solution. For a four-story building and 100 trials, the difference in weight between the optimal and worst solutions obtained by the PSO is less than 2.2% and 2.5% for the two frames, respectively. The weights of the best solution obtained by the algorithm for the two frames were validated with a commercial software.
Novel Optimization Algorithm for Composite Steel Deck Floor Systems: Peloton Dynamics Optimization (PDO) (ST48)
Gérard Poitras - Université de Moncton, Gabriel Cormier - Université de Moncton, Armel Stanislas Nabolle - Université de Moncton
In structural steel buildings, one of the most common floor systems is composed of concrete-filled ribbed steel decking supported by wide-flange beams and girders. Traditional design approaches for choosing the components of this typical composite floor system are usually based on the experience of the design engineer. Since there are many possible combinations to this problem (over a billion), it is difficult to guarantee that the final design is the most economical one. Different metaheuristic optimization algorithms have been used to address this design problem with different degrees of success. In particular, the efficiency of some of these algorithms is diminished because of their difficulties in dealing with integer numbers representing the components of the composite floor system. For this study, a novel optimization algorithm is presented based on peloton dynamics that occur during bicycle racing. Peloton dynamics are largely attributable to the physical capacity of cyclists, energy saving by the coupling effects of drafting, and the capacity for cyclists to pass others. It also includes cooperation with other cyclists by changing positions inside the peloton, competitors’ positions and their relative energy levels. The optimization procedure used is based on strength, serviceability, performance and cost criteria. The concrete slab + steel deck + steel beams floor configuration used in this study meets all the requirements of the Canadian standard for Design of Steel Structures (CAN/CSA S16-09). The algorithm optimizes the size of all structural elements including girders, beams, slab and deck. The performance of the PDO is compared with other optimization algorithms based on the success rate (ability to find the best solution) and computational effort required. Results indicate the PDO performs better than other metaheuristic optimization methods and requires less user input parameters.
Calgary flood mitigation research (DM37)
Colin Rennie - University of Ottawa, Parna Parsapour-Moghaddam - University of Ottawa, Brian Perry - University of Ottawa, Jonathan Slaney - City of Calgary, Andrew Cornett - National Research Council, Canada, Paul Knox - National Research Council of Canada
The catastrophic 2013 Alberta flood that inundated downtown Calgary may have been Canada’s costliest natural disaster in terms of total damages. The flood caused five deaths, required evacuation of 100,000 people, and resulted in an unprecedented $5B-$6B in estimated damages. Subsequently, the Province of Alberta and City of Calgary have undertaken extensive engineered mitigation works to minimize the consequences of future flood events. This paper begins with a brief overview of the flood, followed by research that has informed engineering design of proposed mitigation works; morphodynamic numerical modelling of Bow River, and physical modelling of the proposed Springbank Diversion on the Elbow River.
Morphodynamic models of Bow River were developed using the Delft3D package, including the reach from Bearspaw Dam to the Calgary Weir. Pre- and post-flood surveys of river bed bathymetry were used to calibrate morphodynamic predictions of the model. The model is being used to assess proposed flood mitigation and fish habitat enhancement works, such as manipulation of mid-channel bars.
A large scale (1:16) physical model of the proposed Elbow River Springbank Diversion was constructed at the National Research Council’s (NRC) Ocean Coastal and River Engineering (OCRE) Research Centre in Ottawa. The model included structures to divert flow from the main river channel to a constructed diversion channel, structures to regulate flow down-river, as well as realistic representation of the approach channel and floodplain. Designs of the diversion and main channel structures were studied and optimized based on model test results to ensure adequate conveyance and control during flood conditions as well as minimal blockage by sediment and woody debris. Natural woody debris was employed during model testing, which proved to be important for realistic model representation of debris jamming.
Blast Performance of Cross-Laminated Timber Panels with Realistic Boundary Conditions (DM11)
Dominic Côté - University of Ottawa, Christian Viau - University of Ottawa, Daniel Lacroix - Carleton University, Ghasan Doudak - University of Ottawa
This paper presents a recent study which investigated the effects of realistic boundary conditions on the behaviour of cross-laminated timber (CLT) panels when subjected to out-of-plane blast loads. Experimental testing was conducted at the University of Ottawa Blast Research Laboratory, where shock waves were generated and applied through the use of a shock tube test apparatus. Connection configurations with seismic detailing were considered, in order to evaluate whether existing structures have adequate capacities to resist a given blast load with desired damage in the primary structural elements. Typical connections used in construction to resist gravity and lateral loads, as well as connections designed specifically to resist a given blast load, were also investigated. The results indicate that the detailing of the connections appears to significantly affect the behaviour of the CLT panel. Bearing type connections performed better than those composed of only wood screws, which tended to fail in a brittle manner. It was observed that under-designed steel angles provided significant energy dissipation through steel yielding and wood crushing, resulting in reduced panel damage. The study also concluded that using simplified tools such as single degree-of-freedom (SDOF) modelling together with current available material models for CLT may not be sufficient to adequately describe the behaviour and approximate the damage.
An Experimental Study on Damage-resistant Reinforced Concrete Shear Walls (ST17)
Mohammad Javad Tolou Kian - University of Alberta, Carlos Cruz-Noguez - University of Alberta
Today, reinforced concrete (RC) structures are designed to deform in a ductile manner when resisting strong ground motions. However, when structures deform beyond their elastic limits, sustaining permanent drift ratios and suffering concrete damage, which can lead to costly retrofitting or even demolition and reconstruction plans becomes unavoidable. In this regard, an experimental study was undertaken to explore the seismic performance of three types damage-resistant RC shear walls. The study included the cyclic testing of three innovative shear walls detailed with innovative reinforcements and fibre reinforced cementitious composite (FRCC). The reinforcing system of each specimen consisted of steel rebars and a type of self-centering reinforcement such as shape memory alloy (SMA) bars, glass fibre reinforced polymer (GFRP) bars or high-strength steel strands. Test results showed that innovative shear walls detailed with high-performance materials had reduced residual drift ratios and mitigated concrete damage in comparison to a conventionally designed and constructed control shear wall. In addition, each innovative shear wall exhibited more than 3% of inelastic rotation, which was both code compliant and comparable to that of the control specimen.
Performance of Simplified Biaxial Concrete Materials based on Damage Formulations (ST84)
Jesús Salazar López - University of Alberta, Carlos Cruz-Noguez - University of Alberta, Bernardo Garcia Ramirez - University of Alberta
An accurate prediction of the ultimate capacity of concrete elements is crucial while determining safety margins. Microcracks are the reason for many materials failure, including concrete. Damage is known as the propagation and coalescence of microcracks, which is usually treated as strain softening is structural analysis. Continuum damage mechanics has been used to develop damage models of concrete, which aims to describe the nonlocal behavior of this material.
OpenSEES is an open source code software framework for simulation in earthquake engineering using FE techniques. It has been developed to be a communication mechanism for exchanging and building upon research accomplishments. A scalar damage model (Mazars, 1986) was used to create a new biaxial concrete material in OpenSEES (García, 2017). Although this model has shown accurate results, it should not be employed when the material is confined or subjected to alternated loading.
The objective of this research is to study the performance of biaxial concrete materials. Two existing damage models will be used to develop two independent OpenSEES concrete materials: Mazars’ damage “μ Model” (2013) and the “PRM Coupled Model” (Mazars et al 2010). The analytical analysis generated by the new materials will be compared with experimental tests to assess their performance. In contrast with the majority of FEA software, this project will provide a tool for modeling large-scale 3D or 2D concrete structures using 2D nonlinear elements, without having any restrictions on the number of nodes or elements that can be used. This project will also provide some hints concerning the performance of each material for different types of analysis.
The “μ Model” was developed to include the damaged effects related to monotonic and cyclic loading that were not incorporated in previous models, such as unilateral effects. It has demonstrated capability describing a broad range of nonlinear behavior: monotonic, cyclic, and dynamic loading. The “PRM model” is able to simulate a large range of dynamic loading as the “μ Model”, but it also accounts for permanent strains. A comparison between analytical and experimental data is used to evaluate the performance of the new materials. The relevance of this work is to provide the research community a new and sophisticated, yet simple tool to implement precise concrete nonlinear models using 2D elements, which will allow them to compare their analytical and experimental data.
Analysis Model for Slender Masonry Walls: Aspects of Structural Response (ST47)
Clayton Pettit - University of Alberta, Carlos Cruz-Noguez - University of Alberta, Mark Hagel - Alberta Masonry Council
A slender masonry wall is currently defined by the Canadian guidelines for masonry structures (CSA S304-14) to have a slenderness ratio greater or equal to 30. Slender walls are an attractive structural option for low-rise construction, such as warehouses, school gymnasiums, and retail stores due to their low construction costs. The code provisions for slender walls are based on observations from experimental programs dealing with these slender walls, basic principles of mechanics of materials, and practical considerations arising from masonry workmanship. However, due to the difficulties in studying walls with high slenderness, very few experimental tests dealing with masonry walls with slenderness ratios greater than 30 have been conducted and in turn, aspects of the structural response of these slender masonry walls are still not well understood. Such aspects include the effective stiffness at failure, deformation, stability, safety limits on the axial loads that these walls can carry, and the influence of the grouting extent (i.e., fully grouted walls vs. partially grouted walls). An alternative to testing is numerical modeling, but the tools chosen for structural simulation must be reliable, sound, and validated with experimental results. In this study, a simplified, yet robust analysis model for masonry walls based on basic mechanics of materials is developed. The model implements a fiber-section approach to account for the nonlinearity of the masonry and reinforcement materials in the moment-curvature response. Second-order effects are integrated into the model by solving the pertinent differential equations that govern the deformation of beam-columns. The analysis model is validated with experimental tests conducted by ACI-SEASC Task Committee on Slender walls. Once verified, parametric studies are conducted to analyze the strength, stability, and the ductility of both fully and partially grouted slender walls. The limitations of the model are discussed, and design recommendations are provided.
Sediment Transport Modelling in Support of Dam Renewal Decision-Making (EN44)
Katy Haralampides - University of New Brunswick, Gordon Yamazaki - Canadian Rivers Institute, UNB, Mouhamed Ndong - Canadian Rivers Institue, UNB Civil Eng, Allen Curry - Canadian Rivers Institute, UNB Biology
Authors: Mouhamed Ndong1, Katy Haralampides2, Gordon Yamazaki1, Allen Curry1,3, Karl Butler4, Mitch Grace4
1 Canadian Rivers Institute, University of New Brunswick, Fredericton, Canada
2 Department of Civil Engineering, University of New Brunswick, Fredericton, Canada
3 Department of Biology, University of New Brunswick, Fredericton, Canada
4Department of Earth Sciences, University of New Brunswick, Fredericton, Canada
The Mactaquac Generating Station (MGS), a 672 MW run-of-the-river hydroelectric facility on the main stem of the Saint John River, New Brunswick, Canada was built in 1968 by NB Power. The Canadian Rivers Institute is undertaking the Mactaquac Aquatic Ecosystem Study (MAES), a planned, whole-river multidisciplinary ecosystem study and manipulation of the MGS, in support of a decision-making process regarding the future of the aging facility. Future options under consideration range from in-situ restoration to full removal and river restoration.
Prediction of the potential transport and fate (or long-term retention) of post-inundation sediment is a crucial aspect for decision-makers. Extensive bathymetric surveys, sediment surveys, core sampling, and laboratory studies were conducted to estimate the volume of sediment upstream, sediment bed composition, thickness, particle size diameter, erosion rate and threshold shear stress. These results were integrated into the hydrodynamic model Delft3d that was previously calibrated and validated.
The model results predicted the downstream fate of the sediments under various hydrodynamic regimes, including the case of complete removal of the hydraulic structure. Given drawdown scenarios were simulated, and sediment movement was quantified. For the case of in-situ restoration, sediment transport simulations were used to predict the long-term effects of sediment retention in headponds on downstream sediment-dependent wetlands. The sediment transport studies have helped to identify areas of interest for future research focus, and have furthered the field and laboratory techniques undertaken by the team. The results of the MAES project will help to advance the science of dam renewal decision-making processes using a holistic, multidisciplinary approach.
Investigating the risks imposed by different driver groups on other road users (TR15)
Essam Dabbour - Abu Dhabi University, Thomas Philip - Ryerson University, Said Easa - Ryerson University, Canada
Multi-vehicle traffic accidents usually result in increased injury severities to the more vulnerable drivers involved in those accidents. An obvious example is the case of an accident between a heavy vehicle and a motorcycle, which usually results in an increased injury severity to the motorcyclist. However, there is a lack of quantified measures that estimate the level of risk imposed by different driver groups on other road users. As an example, there are no quantified measures available to estimate the level of risk imposed by impaired drivers on other road users. This paper provides quantitative investigation regarding the level of risk imposed by different driver groups on other road users. The research is based on analyzing accident records from North Carolina for all two-vehicle collisions that occurred between January 1, 2004 and December 31, 2013. Different driver groups are investigated based on driver’s gender, age group, impairment, and the type and age of the vehicle used by the group. To eliminate the random effect of the number of passengers in the vehicle, only drivers’ injuries are considered in the analysis. For each pair of groups, the number of collisions where the driver was at least visibly injured is compared between the two groups and based on that an estimate is made to the odds of every driver group to increase the severity of injuries of other driver groups. The findings of this research may help decision makers identify driver groups that are more dangerous to other road users so that more resources might be allocated to improve awareness programs and licensing procedures dedicated to those groups. The findings of this research also provide quantified measures for insurance companies and law enforcement agencies regarding the potential liability imposed by different driver groups on other groups.
Structural Health Monitoring of Legacy WWII Infrastructure within the Department of National Defence, a Stage-Wise Approach (GC84)
Henry Helmer-Smith - Royal Military College of Canada, Nicholas Vlachopoulos - GeoEngineering Centre, Queen's-RMC, Marc-Andre Dagenais - RMCC, Bradley Forbes - Department of Geological Sciences and Geological Engineering, Queen's University
Structural Health Monitoring (SHM) programs have been widely adopted in structural engineering applications for knowledge, control, and emergency purposes. SHM programs aid in understanding the behaviour of structures, both globally and locally, and essentially provide the quantitative link between the design and actual performance of structures. The focus of this research is the long-term SHM of a ‘temporary’ World War II era timber Warren truss Air Force hangar located at a Canadian Forces Base (CFB) in St-Jean, Quebec. Hangar 1 is one of approximately 70 Warren truss structures still maintained by The Department of National Defence (DND). Originally designed as a temporary structure, this Warren truss warehouse has been subjected to environmental stresses, extreme material degradation, and extensive rehabilitation efforts. As a result, the structure exceeds serviceability and structural capacity limits leading to evacuations at snow accumulations of 100 mm, thus warranting an SHM system. This SHM endeavour will be achieved by implementing a robust monitoring plan, utilizing multiple instruments capable of determining the behaviours of selected Warren trusses within the overall structure. To achieve this objective, firstly, a scaled-down truss was created and tested within a laboratory environment at the Royal Military College of Canada (RMC). Critical monitoring locations were confirmed by multiple forms of monitoring and by means of numerical modelling. These preliminary results contribute to the current implementation of an optimal in-situ, remote, long-term SHM program in Hangar 1. This SHM program combined with predetermined serviceability and structural integrity limits will provide real-time alarms for evacuation purposes, an overall increase in occupant safety, and an insight into the behaviour of these complex, legacy structures.
Incorporating physiological stress measures into assessment of driver performance: Implications for methodology and design (TR36)
Jessica Sutherland - Ryerson University, Udai Hassein - Ryerson University, Canada, Said Easa - Ryerson University, Canada, David Day - Ryerson University
Despite the evidence suggesting that physiological stress can compromise cognitive functioning and decision-making, there is a paucity of literature on the effects of physiological stress on driver behaviour and performance. This paper reviews the literature on physiological stress and decision-making, prior research on physiological stress and driving, and methodological considerations for effectively incorporating physiological data with driving performance. In particular, we will highlight implications and recommendations for future studies on driver stress and performance. These recommendations include selecting driver behaviours and experimental manipulations to improve ecological validity. As well, we discuss the benefits of incorporating physiological stress measures into experimental driving research to capture human factors related to driver decision-making. Finally, we include as an example the preliminary results of a study incorporating physiological stress into a model exploring peer passenger effects on young driver performance. We measured physiological stress via wearable biopotential recording sensors while male and female participants, ages 16 to 25 years, completed tasks either alone or with a peer, before driving. We use these preliminary findings to describe how to select stressors appropriate for the population and stress measurement tools appropriate to the methodological design.
Proposed model of adolescent risky driving: Integrating social stressors and physiological stress as predictors of driver performance (TR20)
Jessica Sutherland - Ryerson University, Udai Hassein - Ryerson University, Canada, Said Easa - Ryerson University, Canada, David Day - Ryerson University
Peer passengers increase the likelihood of fatal collisions among adolescent drivers. Previous research suggests that social acceptance is especially important to adolescents and that peer presence can induce physiological stress, compromising inhibitory control over risk-taking. Despite the evidence for this peer effect, an understanding of the specific mechanisms of how and when peer passengers can influence a young person’s driving behaviour is lacking in the literature. Examining the effects of peer influence under different social conditions in a driving simulator will further our understanding of the relationship between young passengers and driving outcomes. Further, physiological stress has not been explored for its effects on driving in young drivers. This study tested the effects of a social stressor on driving behaviour in a driving simulator, including acceleration, speeding, and lateral displacement. Male and female participants between the ages of 16 and 25 were randomized to control and social stressor conditions (peer rejection or acceptance). Participants’ cardiovascular stress physiology was measured while completing tasks either alone or partnered, and during a simulated drive. A significant interaction effect emerged with condition, gender, and physiological stress, as well as a significant main effect for condition on acceleration and lateral displacement. Assessing peer effects under different social circumstances while driving contributes to the growing literature on the connection between peer passengers and driving behaviour in young people.
The role of rock direct shear testing and practical aspects of boundary conditions (GC123)
Timothy Packulak - Department of Geological Sciences and Geological Engineering Queen's University, Jennifer Day - Department of Earth Sciences, University of New Brunswick
Laboratory direct shear testing is a critical tool used to characterize the stiffness and strength behaviour of rock joints and other fractures in geotechnical engineering. Constant normal stress (CNL*) boundary conditions are considered to represent fracture behaviour in slopes and other near surface gravity-driven environments, while constant normal stiffness (CNS) boundary conditions are considered to be better suited for rock fractures near underground excavations, such as tunnels, mines, and nuclear waste repositories, where in situ and induced stresses dominate rockmass behaviour. This paper will discuss the role of direct shear laboratory testing in surface and underground civil construction projects. Laboratory CNL conditions are achieved by maintaining the normal actuator at a constant stress, allowing the joint to dilate. CNS conditions differ as the machine is programed to maintain the normal stiffness, so as the joint dilates the normal stress increases.
While CNL* conditions are well documented and straightforward, a detailed literature review of CNS boundary conditions has revealed few details regarding appropriate laboratory testing conditions. This paper will present practical guidelines needed for designing an effective suite of constant normal stiffness test conditions that can be applied to a variety of rock types based on intact rock elastic properties.
The results of direct shear tests that are being conducted in this research under both boundary conditions will be compared and discussed. These tests are being conducted on natural fractures through NQ and NQ3 size drill core of gneissic tonalites and granites of the Canadian Winnipeg River Complex within the Pointe Du Bois Batholith. The gneissic tonalites and granites are equigranular, medium to coarse grained and are unfoliated to weakly foliated; the joints are smooth to semi-rough, planar to sub-planar and generally fresh with trace mineral coating. Direct shear sample deformation properties including normal stiffness and shear stiffness, as well as the strength properties (shear strength and post-peak dilation behaviour), will be analyzed in this study. In particular, a practical method to determine dilation and total dilation potential will be discussed.
These sample deformation properties are all needed for parameter inputs to accurately define the mechanical behaviour of the rock joints in explicit and discrete geomechanical numerical models. Explicit numerical models will be used to illustrate differences between numerical models of laboratory scale direct shear tests using input properties from the CNL* and CNS laboratory test conditions, focusing on the application of dilation angle and dilation potential.
Integrating healed intrablock rockmass structure into geotechnical design (GC143)
Jennifer Day - Department of Earth Sciences, University of New Brunswick
In modern rock engineering projects such as civil infrastructure base tunnels and base metal mines featuring particularly deep (>500 m) underground excavations and large open pit slopes, effective geotechnical characterization of the rockmass is critical to the initial excavation and ground support design, and to the accurate prediction of rockmass behaviour throughout project development. Base tunnels are being constructed to expand civil transportation and irrigation infrastructure through major mountain ranges such as the Andes in South America. Large-scale open pit and block cave mining methods are popular approaches to exploit large orebodies due to the high projected global supply and demand forecasts, increased production rates, and improved worker safety.
Modern geotechnical design of these projects typically incorporates field examination of rockmasses, preliminary assessment using conventional rockmass classification systems, laboratory analyses of mechanical properties, and numerical simulations to predict ground behaviour and investigate detailed ground support options. Various suggested methods and guidelines have been developed for these design stages in conventional rockmasses comprised of blocks of intact rock that are bound by natural fractures such as joints, bedding, and foliations. Many tunnelling and mining modern rock engineering projects, however, are being developed in more complex rockmasses that contain healed intrablock structures, such as hydrothermal veins and stockwork, within blocks of intact rock. In particularly deep mining excavations at high stresses, these structures have been observed to control additional or delayed development of ground failures, through what is traditionally considered to be intact rock, or a predictable, naturally-fractured rockmass. These unexpected ground failures require additional ground support on a reactive basis, which increases the safety risk to workers as well as project ground support costs. As excavations continue to go deeper, fractures will have less influence on rockmass behaviour, but intrablock structures have no depth limit and will have increasing effects on stability, safety, and mine economics.
This paper will discuss the methods available to integrate intrablock rockmass structure into various stages of geotechnical design of deep excavations in complex rockmasses. These stages include (i) site investigation and field data collection from outcrops and drill core; (ii) laboratory testing options such as intact compressive, intact tensile, and discontinuity direct shear tests; (iii) continuous numerical modelling; and (iv) discontinuous numerical modelling.
Direct modelling of dynamic sol-structure interaction by finite elements analysis (DM34)
Marc-Denis Rioux - École de technologie supérieure (ETS), Nollet Marie-José - École de technologie supérieure, Bertrand Galy - Ecole de Technologie Superieure, Sanda Koboevic - Ecole Polytechnique de Montreal, LeBoeuf Denis - UiversitÃ© Laval
Under strong ground shaking, both structure and the underneath soil display highly nonlinear response and contribute to dissipate seismic energy through large permanent deformations. While the ductility of the structure is commonly considered in seismic design, the benefits of nonlinear soil response are not explicitly incorporated into codes and standards for seismic design and assessment. For existing buildings such approach may lead in some circumstances to unnecessary retrofits (ex.: adding shear walls, bracing, etc.). It is thus of interest to investigate how the inclusion of the nonlinear soil response affects the dynamic behavior of existing buildings and what are the consequences on seismic assessment.
The study presented in this paper focuses on the development of an integrated soil-structure model in which the energy dissipation from permanent deformation in the soil and from rocking is considered through direct modelling of dynamic-soil-structure interaction (DSSI). The dynamic response of the prototype building, framed by moment-resisting frames, is then evaluated with and without consideration of DSSI. Finite element bi-dimensional numerical models of integrated soil-structure system are developed on the OpenSees analysis platform. The absorbing boundaries, proposed by Lysmer-Kuhlemeyer are used on the lateral model’s frontier to represent energy absorption and prevent reflection inside the grid. Inelasticity of the soil is considered by the PressureDependMultiYield material of the OpenSees librairie while the frame elements (beams and columns) are modelled as inelastic elements using fiber section. The whole model is built in a unique sequence, allowing a combined analysis in the time domain of both the soil and the structure. A complex interface provides the link between the soil and the structure and allows for the definition of various conditions in all degrees of freedom.
When compared to a standard analysis model, which uses discrete mechanical element (springs and dampers) to simulate the soil behaviour, the developed model directly simulates the effect of the structure on the dynamic response of the soil and vice-versa. To date, the model shows excellent agreement with theoretical, numerical and published experimental results both in the static and dynamic domains. The study is on-going to investigate the use of the model for different structural systems and soil conditions.
The uses of polymers in concrete: Potentials and Difficulties (MA63)
Ahmed Soliman - Concordia University, Romaric Desbrousses - Concordia University
This paper aims to understand and evaluate the potentials of using polymers in concrete for different construction applications. Initially, polymers will be defined from a chemical perspective and their general mechanical behavior is explained in order to provide an insight on the benefits of using polymers in concrete. Three types of polymer concretes, namely Polymer Concrete, Polymer-Impregnated Concrete and Polymer-Modified Concrete, are then thoroughly described to present their respective mechanical behaviors, advantages, disadvantages and possible applications. The challenges of using polymer concretes are then discussed as well as the possible future development and uses of such materials. This would allow engineers and policy makers to consider polymer composites as a sustainable constrution material for different civil structures.
Modal Analysis and Damping of Bridge Light Poles (ST39)
Serge Desjardins - Université de Moncton, Gérard Poitras - Université de Moncton, Donald McGinn - Strait Crossing Bridge Limited
This study aims to provide a better understanding of the dynamic behaviour of light poles installed on bridge decks subjected to significant winds and to propose a damping solution to attenuate the large amplitude vibrations that contribute to fatigue failure.
The subject of this study is the light poles installed on the Confederation Bridge in eastern Canada. The unique nature of this 12.9km bridge and its location in the Northumberland Strait provides an opportunity to study light pole vibrations in harsh environmental conditions. Accelerations of wind as it flows over the 15m deep bridge structure and the absence of pole foundation dampening result in a system sensitive to induced motion. Light pole failures have occurred during several strong wind events, the latest of which had wind gusts of 151 km/h. Large amplitude vibrations of the light poles were observed during this event.
To attain the objectives stated, the full-scale vibration testing of two installed light poles was carried out on the deck of the Confederation Bridge. The laboratory testing of a light pole was also carried out to validate the testing methodology. Four wireless tri-axial accelerometers installed on the light poles captured the free vibrations of the poles subjected to pull and release excitations. Results were obtained via two experimental modal analysis techniques: the logarithmic decrement method and a variant of the stochastic subspace identification technique. The extracted modal properties were compared to the analytical modal properties obtained from finite element modelling. The experimentally obtained modal properties (frequency and mode shapes) correlate well (within 4%) with those obtained analytically.
To attenuate the large amplitude vibrations, the second part of the study focused on pole-top impact dampers by comparing the damping performance of five custom prototypes and a commercial option. A prototype impact damper using two lead balls within a pipe cylinder added to the top of the pole was found to exhibit comparable or better damping behaviour under large displacements than the commercial damper. To validate the prototype, two adjacent poles on the Confederation Bridge have been monitored over a period of several months. One pole was outfitted with the selected custom pole-top impact damper and the other pole was serving as a control. Data was captured under several wind events of varying wind speeds and direction in the fall of 2017. Initial results suggest that the custom damper is effective in reducing pole top displacements during strong wind events.
Development of Passing Collision Warning System Prototype for Overtaken Trucks on Two-Lane Highways (TR18)
Udai Hassein - Ryerson University, Canada, Maksym Diachuk - Ryerson University, Canada, Said Easa - Ryerson University, Canada
Passing collisions are one of the most serious traffic safety problems on two-lane highways. These collisions occur when the driver cannot correctly assess the situation. This paper provides the framework design for a passing collision warning system (PCWS) that assists drivers in avoiding passing collisions on two-lane highways by reducing the chance of human error. The system uses a camera as well as a radar sensor to identify the impeding vehicle type and to detect opposing vehicles travelling in the oncoming lane. The objectives of this research are: (1) to design driving simulator experiments for data collection in order to calculate passing parameters, (2) to develop the PCSW algorithm based on camera and radar sensor signals for trucks (as the impeding vehicle), (3) to develop the driver handling model that describes situations in which steering wheel action is necessary for lane changes and maneuver interruptions, and (4) to develop SUV and articulated vehicle dynamic models which are represented as universal Simulink blocks combined in one simulation scenario. The simulation series was carried out in order to confirm the effectiveness of the PCWS algorithm. This study involved the investigation of the effect of driver behaviour on passing maneuvers, and the development of the algorithms for a PCWS that assists drivers in the selection of proper passing gaps during passing maneuvers. Certain techniques, such as mathematical and imitation models, were enhanced in order to replicate real-life driving situations in Simulink. The different factors that affect system accuracy were also examined.
Here and Now (GC164)
Ata Khan - Carleton University, Alan Perks - University of Ottawa, Canada, Gordon Lovegrove - University of British Columbia, Canada, Edwin Tam - University of Windsor, Catherine Mulligan - Concordia University, Colin Rennie - University of Ottawa, Rozalina Dimitrova - University of Ottawa, Canada
The pace and potential impacts of climate change are now recognized by all major engineering and scientific societies as a crisis requiring urgent and immediate action. There are new and innovative technologies being developed to mitigate and adapt to the situation. The overarching question, however, is will there be sufficient renewable energy to permit all 11 billion humans on earth in the next 100 years to enjoy a modern energy and infrastructure dependent quality of life similar to the one enjoyed by only the 2 billion in advanced economies now. Very likely, the answer is “no”, as CSCE President Claude Johnson predicted in 1994. As a society, and as professional engineers, we must look beyond mitigation and adaptation, and instead focus on avoiding and eliminating carbon energy utilization and GHG emissions in the “here and now”. Otherwise the trajectory of atmospheric CO2 concentrations, and corresponding ocean acidification, will result in an environmental catastrophe for the planet. Civil engineering education and practice must address this issue in education and practice, and the CSCE can play a vital role in this mission.
Design Considerations for Cross-Laminated Timber Panels Subjected to Simulated Blast Loads (DM10)
Christian Viau - University of Ottawa, Daniel Lacroix - Carleton University, Ghasan Doudak - University of Ottawa
This paper presents the results from an experimental program investigating the out-of-plane behaviour of cross-laminated timber (CLT) panels under static and simulated blast loading. A total of eighteen CLT panels were investigated with the aim to determine the dynamic behaviour of CLT panels. Dynamic testing was conducted through the use of simulated blast loads produced by a shock tube testing apparatus. An average dynamic increase factor (DIF) on the resistance is developed. Two material predictive models are proposed, which take into consideration high strain rate effects, failure modes, and the experimentally observed post-peak residual properties. A single degree-of-freedom (SDOF) model was validated using full-scale simulated blast load test results, and the predictions were found to match well with the experimental displacement-time histories. Current Canadian Blast Design Standard provisions were found to provide relatively conservative and accurate predictions when using the proposed DIF and analytical model.
Design Considerations for Glulam Beams and Columns Under High Strain-Rates (DM16)
Daniel Lacroix - Carleton University, Christian Viau - University of Ottawa, Ghasan Doudak - University of Ottawa
An experimental program investigating the behaviour of glulam beams and columns under high strain rates subjected to simulated blast loading was undertaken. Key observations from the full-scale tests such as the dynamic increase factor (DIF) and failure modes are presented in this paper. A DIF of 1.14 was found to be present only in the absence of continuous or closely aligned finger-joints (FJs) in the outer tension laminations. No increase was observed when continuous or closely aligned FJs were present. The behaviour was observed to be linear-elastic with no significant post-peak capacity. Also, no DIF was observed on the stiffness of the glulam members. A more refined approach using moment-curvature analysis and incorporating second-order effects in the design resistance curve yielded a more reasonable match with the actual behaviour of the glulam beam and column elements.
FRP Reinforced Glulam Beams Under High Strain-Rates (DM17)
Daniel Lacroix - Carleton University, Ghasan Doudak - University of Ottawa
An experimental program investigating the potential for using fibre-reinforced polymers (FRP) as a strengthening option for glulam beams subjected to simulated blast loads was undertaken. A total of seven different retrofit configurations were investigated. Increases in resistance and maximum deflection at peak resistance in the range of 1.35-1.57 and 1.30-1.62, respectively, were obtained when FRP tension laminates with and without confinement were used. The addition of FRP confinement prevented premature de-bonding and significantly altered the failure mode from simple or splintering tension failure to a combination of brash tension and compression failure while limiting the damage to a small region. Whereas the use of unidirectional FRP as confinement did not contribute significantly to the post-peak resistance, the use of bidirectional FRP significantly improved the post-peak resistance above the 50% threshold for deflections corresponding to 1.57-3.40 that recorded at peak resistance.
A Comparative Study of Methods for Analyzing Aluminum Pony Truss Structures (ST146)
Scott Walbridge - University of Waterloo, Dylan Dowling - University of Waterloo
Truss bridges constructed without overhead bracing between the top chords, also known as “pony trusses” are particularly common in pedestrian bridge applications, where the bridge top chords can also serve as the handrails or barriers. The lack of overhead bracing allows pedestrians and bicyclists to traverse the bridge unimpeded but results in a unique failure mode due to out-of-plane or lateral buckling of the compression chord members. Various methods have been proposed to analyze this phenomenon, including the ones by Holt in 1952, Timoshenko and Gere in 1961, Alberta Transportation in 2016, and the British Standards Institution in 2000. These methods vary significantly in terms of their implementation; some use an equivalent stiffness based on the ‘U-frame’ stiffness provided by each bay’s verticals and diagonals, while others rely on 3D modelling to determine an elastic buckling load. In the current study, all four methods are compared across a range of section properties that affect top chord compression capacity using the example of a 46’ (14.0 m) aluminum pedestrian bridge. From the initial comparison, it was found that the Timoshenko and Gere and Alberta Transportation methods gave similar results, while the Holt and BS 5400 methods were relatively conservative. The Timoshenko and Gere and Alberta Transportation methods do not generally align across the investigated range of section properties, however. Given these results, further study is recommended to better assess which method can be considered the most accurate or consistently conservative across the broadest range of bridge configurations.
Service Life Extension: Oyster Creek Bridge Rehab Case Study (ST168)
Augustin Dukuze - Dept of Civil Engineering, UNB, Darrell Evans - PEI-DOT
Aging highway infrastructures have been posing challenges to Departments of Transportation across Canada. It should be noted that this is not limited to Canada since most of the highway structures ecosystem has been built after the second world war. Hence in any given jurisdiction, there is a number of bridges that require either extensive rehabilitation or replacement. In the times of limited budgetary resources, the DOT maintenance departments are called upon to devise strategies to do more with little. It is even more challenging when these structures are in harsh marine environment such as the one prevalent in Maritime Provinces.
The present case study presents how PEI Department of Transportation has been over more the last decade tackling the challenges of managing its aging highway bridges. The present case study shows how combining the usage of modern materials could result in the service life extension of an extensively damaged bridge. Hence, the selected case would provide rehab details that were implemented by the PEI-DOT maintenance department relative to one of the first structures on which FRP composites were used to strengthen the given bridge. Not only its service life was extended - bridge still in service today- but the repair costs were a small fraction of the what would have been if the replacement had been in works.
Emboldened by such a success, the Department has extended such solution to several other structures that were in need of repairs.
Climate Change Considerations within the Asset Management of Core Infrastructure for Rural Ontario Municipalities – An Initial Assessment (GC126)
Shawn Kenny - Carleton University, Kathryne Dupré - Carleton University, Amanda McEvoy - Carleton University
Municipalities provide stewardship of infrastructure through asset management plans. These plans are generally focused on service-based outcomes to meet municipal strategic goals. Because uncertainty exists with the potential impact of climate change effects on infrastructure performance, it is important to understand the current state of municipal readiness to address climate change effects, as well as the broader municipal needs, challenges and gaps (e.g. technical, financial, organizational factors). If municipalities do not consider the impacts of climate change in their infrastructure planning, they could experience a greater risk of damage to their infrastructure stock, and there could be significant costs and losses in the future. A preliminary assessment of climate change considerations within asset management plans for rural Ontario municipalities is explored in this study. The general readiness landscape is synthesized and a discussion on the path forward is presented.
Improved Earthquake Resilience with Performance-Based Seismic Design in Canada (DM35)
Hélène Dutrisac - University of Ottawa, Murat Saatcioglu - University of Ottawa
The focus of current Canadian traditional code-based seismic design is to primarily ensure life safety of building occupants. This objective is currently achieved by satisfying prescriptive criteria expressed in terms of drift and strength requirements as prescribed by the National Building Code of Canada or the Building Code in effect under the applicable jurisdiction. However, earthquakes in the last decade such as Chile (2010) and New Zealand (2011) have clearly demonstrated that these natural disasters can have devastating social and economic impacts. Many of the large urban centres in Canada are located within zones of moderate to high seismicity and are susceptible to the effects of major seismic events. Whereas conventional code-based design focuses on meeting prescriptive requirements, Performance-Based Seismic Design (PBSD), a relatively new and emerging seismic design methodology, provides various stakeholders with a better appreciation of the expected performance of a building during a seismic event, often expressed for various levels of ground shaking. This paper provides a synthesis of the state of practice in performance-based seismic design of buildings around the world, with a particular emphasis on reinforced concrete shear wall buildings. Topics explored include current Canadian code-based seismic design procedures, existing worldwide performance-based seismic design procedures, targeted building performance levels, hazard levels, performance objectives and acceptance criteria. This methodology is then examined for adaptation to a Canadian design context. Needs for future research are also identified.
Reliability of Stopping Sight Distance at Roundabouts (TR35)
Jafar Faizi - Ryerson University, Said Easa - Ryerson University, Canada
The existing Stopping Sight Distance (SSD) determination method for roundabout is deterministic where all design parameters are predetermined fixed values. This study represents a probabilistic (Reliability-based) method for determination of required SSD at roundabout based on equation recommended by “Policy on Geometric Design of Highway and Streets” (6th Edition), named as AASHTO Green Book, for calculation of SSD. The reliability based method for determination of required SSD at roundabout considers all design elements (vehicle speed, perception-reaction time, and vehicle deceleration rate) as random variables. In this method, correlation of random variables is taken into consideration. Three types of SSD (SSD for approaching vehicles, SSD along circulatory roadway, and SSD for exiting vehicles to pedestrian crosswalk) at roundabout are considered in this study. A safety margin for SSD is defined as SSD provided by the roundabout geometry minus SSD required based on vehicles and driver’s performance characteristics. First-Order Second-Moment (FOSM) and Advanced First-Order Second-Moment (AFOSM) methods are used for SSD calculation at roundabouts. Once the required SSD is determined, Lateral clearance distance can be obtained on every single point of the roundabout curves. The probabilistic method is applied to a numerical example and comparison is made between the results of (FOSM), (AFOSM), and deterministic method. Reliability-based SSD design method will provide designer insight into the safety of provided SSD.
Freeway Work Zone: Current Trends and Future Needs (TR17)
Udila Pilanavithana - Ryerson University, Said Easa - Ryerson University, Canada, Xiaobo Qu - Chalmers University of Technology
Work zones are recognized as a significant source of freeway incidents as they involve frequent lane closures and lane merges that last for different periods of time. Work zones generate road user delays, traffic incidents, safety hazards, and vehicle emissions. This article presents a comprehensive literature review of the mobility, safety, driver behaviour, and cost and planning aspects of state of the art work zones. Over 100 publications, including research papers, master thesis, and dissertations were reviewed in order to understand the spread of work zone applications.
Mobility and safety have become important measures that have been used to optimize the performance of work zones by minimizing delay and traffic collisions. Work zone configuration plays a major role in all aspects. Lane merging and speed limit impacts are critical issues for mobility. The review revealed that safety is mostly modeled and predicted using collision data as the main factor. Temporary traffic control devices become a more significant parameter to researches on safety during the past few decades. The impact of nighttime safety attracted less research attention. Cutting-edge smart work zone concepts have emerged as a key component in most of the phases of work zone studies. Driver behaviour is explored as one of the main considerations that affects the entire work zone aspects. Demographical and psychological phenomenon are thoroughly examined whereas modern technology mostly involves driver behavioural measures. Finally, optimal planning and cost minimization strategies are proposed to incorporate in reliable scheduling and refined policies in states and agencies to present more effective and user ready work zone environment. In addition, methodologies adopted to explore and validate the logics and developed models are comprehensively evaluated in this study. Advanced statistical tests and regression analysis are adopted in most studies. Existing field and experimental data are widely used in the studies reviewed. Micro-simulation software, such as VISSIM and CORSIM are popular among researchers. Advanced driving simulators with real-world virtual environments are also used in many studies to maximize the robustness.
In this article, the important elements of each publication are tabulated to give the reader quick access to the relevant references. Apart from the existing approaches, the design variables, limitations, and future research needs are listed separately for prospective users. Synopsis of references can be found in the same tables. It is our hope that this paper will serve as a quick freeway work zone reference and guide for potential researches and practitioners.
Keywords: Work zones, mobility, safety, driver behaviour, optimization.
Validation of a Simplified Numerical Model to Compute the Dynamic Response of Conductor Systems to Downburst Loading (ST163)
Ibrahim Ibrahim - The University of Western Ontario, Ashraf El Damatty - The University of Western Ontario
With electricity being a cornerstone of our modern world, and a key factor to the growth of communities and their sustainability, the maintenance of a functional electricity transmission network against devastating powers of nature is essential. Studies reported that High Intensity Winds (HIW), which refers to intense wind loading phenomena like tornadoes and downbursts, have been the major cause of transmission line failures across the world. The current study focuses on the effect of downburst loading on the computed longitudinal reactions of electricity conductors on transmission towers. Such reactions are a direct result of the phenomenon’s locality and non-stationarity, which lead to longitudinal reactions that can be deterministic for transmission towers, specially the cross arms that experience devastating bending moment straining actions. To accurately assess the longitudinal reactions due to downburst loading, the current study utilizes a dynamic analysis model that accounts for the non-linearity of conductor cables, along with the associated local and non-stationary nature of loading. The study also highlights the complexity of the analysis introduced by the aerodynamic damping of the conductor cables, which is affected by the non-stationarity of the loading phenomenon leading to a time varying damping value. Consequently, the study proposes an engineered assumption related to the computation of the aerodynamic damping that can greatly simplify the analysis. The assumption that is based on the characteristics of the loading wind field is then validated using experimental data of a wind tunnel scale test of a downburst simulation conducted at the WindEEE dome. The comparison between the numerical and the experimental results show the adequacy of the proposed assumption as an alternative that can reduce the complexity of the analysis by using a single value of aerodynamic damping that is time independent rather than a varying damping value.
Sensitivity Study of Light-Framed Wood Shear Walls Subjected to Lateral Loads (ST105)
Mohammad Niazi - The University of Western Ontario, Ashraf El Damatty - The University of Western Ontario, Mahdy A. Hamada - The University of Western Ontario
The Light-Framed Wood Buildings are considered as one of the most economical and feasible choice for the low and mid-rise buildings in North America and worldwide. The latest changes to the National Building Code of Canada allows construction of up to six-storey light-framed wood building using panelized wood shear walls. The Light-Framed Wood Shear walls consists of different components such as studs, sheathing, chords, top, and bottom plates. These components are connected using nails and mechanical fasteners. The orthotropic characteristics of wood and the nonlinear behaviour of nails add more complexity to the numerical simulation of the Light-Framed Wood Shear walls. The current study presents detailed finite element procedures to model the wood shear walls. The finite element model is verified with two different experiments that are provided in the literature. Both strength and stiffness of the modelled wood shear walls are in good agreement with the experiments. A sensitivity study is performed to assess the critical parameters that affect the strength and stiffness of the wood shear walls. The study shows that the shear stiffness of sheathing-to-frame nails is the most sensitive parameter that affects the lateral response of the wood shear walls. A comparison between the numerical model lateral deflection results and CSA-O86-14 are provided for multi-storey shear wall. The study shows that the wall to floor connections significantly affect the lateral deflection and are not accounted for in the code equations clearly.
Case Study of Seismic Load Reduction Factors on Equivalent Earthquake Loads for High-rise Buildings (ST106)
Mohammad Niazi - The University of Western Ontario, Mahdy A. Hamada - The University of Western Ontario, Ashraf El Damatty - The University of Western Ontario
The design of the lateral load resisting system of high-rise buildings is mainly affected by the level of the wind and seismic loads. An economical design can be achieved when both lateral loads are approximately equal or close to each other. This can be achieved through changing the ductility demand. In the current study, three high-rise reinforced concrete shear wall buildings with different ductility levels and geometry, located in Toronto, Calgary, Montreal, and Vancouver, are used. The study focused on 20 to 60 storeys buildings with height range from 58.1 to 180 m. These cities represent low, moderate, and high seismic regions in Canada. The wind and seismic load provisions provided by the National Building Code of Canada (NBCC) are strictly followed for all buildings in each city. Three-dimensional finite element models of all buildings are developed and verified. The seismic forces are calculated using the equivalent static approach and the response spectrum analysis. Static and dynamic wind procedures are used to calculate the wind loads. The base shear forces, and base overturning moments of two selected shear walls for each building are calculated. By changing the level of ductility demand of each building, recommendations are made for each city to achieve closer wind and seismic loads. The study shows that the ductile design for reinforced concrete shear walls is the optimum system for designing the high-rise buildings in high seismic regions such as in Vancouver. In Montreal, wind loads and ductile structures (Rd Ro = 5.6) approximately have the same loading level on buildings with 30 storeys and above. The study shows that the moderately ductile shear wall systems could economically be accepted for high-rise buildings located in Toronto up to 40 stories, while wind loads govern the lateral load combinations in higher buildings. It is also found that conventional seismic procedure provides loads that are less than wind loads for 30 storeys buildings and above in Calgary.
Causes of Variation Orders in the Egyptian Construction Industry: Time and Cost Impacts (GC10)
Jwanda El Sarag - American University in Cairo, Samer Ezeldin - AUC
Variation orders are of great importance in any construction project. Variation orders are defined as any change in the scope of works of a project that can be an addition omission, or even modification. This paper investigates the variation orders that occur during construction projects in Egypt. The literature review represents a comparison of causes of variation orders among Egypt, Tanzania, Nigeria, Malaysia and the United Kingdom. A classification of occurrence of variation orders due to owner related factors, consultant related factors and other factors are signified in the literature review. These classified events that lead to variation orders were introduced in a survey with 19 events to observe their frequency of occurrence, and their time and cost impacts. The survey data was obtained from 87 participants that included clients, consultants, and contractors and a database of 42 scenarios was created. A model is then developed to help assist project managers in predicting the frequency of variations and account for a budget for any additional costs and minimize any delays that can take place. Two experts with more than 25 years of experience were given the model to verify that the model was working effectively. The model was then validated on a residential compound that was completed in July 2016 to prove that the model actually produces acceptable results.
The Effects of Existence of Transfer Slab System on the Seismic Behavior of Building (ST157)
Mohamed Elassaly - Fayoum University, Mahmoud El sayed - Fayoum University, mohamed Nabil - Fayoum University
A comparative analytical study for structural dynamic behavior of multi-story R.C. building that implies a transfer slab system in one of its floor slab, is presented. The study aims to improve the general understanding of the effects of transfer slab system in the seismic behavior of R.C. buildings. The vertical position of transfer slab system with respect to the building height is investigated. A plane frame model of R.C building subjected to different ground motions is investigated. The ground motion is simulated through sets of natural accelerograms used in time history analyses. The change in behavior of R.C. building models is evaluated by comparing results of maximum story drift ratio, maximum shear story and local damage distribution along the height of the building for different models. The damage indices are obtained through time history analyses for different plane frame models by using modified Park-Ang damage index indication. The time history analysis is performed using computer code IDARC2D . The output based on analyzing and comparing the results of different models to infer some of the principles that should be taken into account when designing this kind of buildings.
Numerical Modelling of Dapped-Ended Concrete Girders Reinforced with Headed Studs (ST74)
Kevin Yuen - University of Calgary, Mamdouh El-Badry - University of Calgary
Dapped-ended girders have reduced cross sections at its ends such that the resulting “L” shaped profiles allow it to rest on top of adjacent girders or support structures. Such members are particularly useful in bridges where it is often convenient to maintain continuity between girders of multiple spans, as well as providing allowance for expansion joints to be implemented. The 12.9 km-long Confederation Bridge, which connects Prince Edward Island with New Brunswick across the Northumberland Strait, dapped-ended girders were used for its hinged spans, which were installed in a “drop-in” fashion. Due to the sudden reduction of the cross sectional depth of the dapped ends, the corresponding effective depth available for shear resistance becomes reduced severely. The re-entrant corners are vulnerable to diagonal shear cracking and ample reinforcement must be provided in these regions to allay such effects. The use of headed studs as the primary shear reinforcement at the dapped ends has been proposed at the University of Calgary. Its main advantage compared to conventional shear reinforcement is the reduction of congestion around the re-entrant corner which improves flow and compaction of concrete. Two analytical approaches – the shear friction and diagonal bending methods – were used to design the reinforcement layout of seven specimens, which were subsequently tested experimentally. Overall, results showed good agreement in failure loads between the experimental and analytical methods.However, several specimens exhibited greater error in one design method over the other when compared with the experiment. To provide further insight into the validity and accuracy of the shear friction and diagonal bending methods, a finite element analysis was conducted to further examine the performance of the tested specimens. Results will be presented in a comparative study between the experimental and numerical regimes concerning member strength and behaviour.
Finite Element Analysis of In-Situ Decommissioned Steel Pipelines Subjected to Surface Live Load (ST130)
Coltin Walsh - University of Calgary, Mamdouh El-Badry - University of Calgary
Steel pipelines are used throughout the energy industry as the primary means of transporting natural gas, crude oil, and petroleum related products and chemicals. When a pipeline permanently ceases operation, it is decommissioned and may be left in place underground. Over time, the pipeline will degrade due to environmental and in-situ conditions. Corrosion is the principal mechanism for the degradation of decommissioned pipelines. Corrosion and degradation reduces the material strength and stiffness of the pipe and the pipe may no longer be capable of bearing the imposed load due to groundcover and surface vehicles. Collapse of decommissioned pipelines poses a risk to both the public and environment. The static structural response of buried decommissioned pipelines subjected to surface load is analyzed using finite element analysis software ABAQUS. The buried pipeline is modelled within a uniform soil block, eliminating the effects of boundary conditions. Pipe-soil interaction is considered assuming a frictional slippage contact definition. The pipe is subjected to both overburden dead load and surface live load. Surface live load is taken as the maximum wheel load of a CL-800 truck using an appropriate dynamic load factor. The effects of various in-situ parameters including depth of bury, soil stiffness, pipe diameter and uniform global corrosion are investigated. The results indicate that for typical depths of bury, soil stiffness and wall thicknesses, the resulting stresses are well below the elastic limit. However, for shallow depths of bury, local deformations and stresses become significant. Migration of the stress concentrations from the pipe springline to the pipe crown is observed for decreasing depths of bury and local effects begin to govern. Maximum Von-Mises stresses increase with decreasing depth of bury, soil stiffness, pipe diameter, and pipe wall thickness.
Using Naturalistic Driving Data to Quantify Driver Following Behavior during Braking (TR24)
Mostafa H. Tawfeek - University of Alberta, Karim El-Basyouny - University of Alberta
This study aims at quantifying and comparing drivers’ following behavior during braking at intersections and midblock road segments (i.e., non-intersection) using Naturalistic Driving Data (NDS) data. The quantification of driver behavior was based on exploring the Probability Density Functions (PDF) of two parameters (i.e., minimum following distance and time-to-collision) which were extracted from NDS data. To classify drivers’ following behavior at intersection and segments, all events were mapped onto the road network using ArcGIS. The intersection events were defined based on the driver’s stopping sight distance to the stop line of an intersection. The results showed that there was a significant statistical difference between the PDFs of the parameters at intersection and segment events. Also, the results showed that drivers tend to keep less following distances and high deceleration rates (i.e., more aggressive) during intersection events when compared to segment events. Generally, the results of this study highlight the importance of considering the driver location before judging or classifying his/her behavior.
Flexural Behaviour of Superelastic Shape Memory Alloys Reinforced Concrete Beams during Loading and Unloading Stages (ST115)
Yamen Ibrahim Elbahy - University of Western Ontario
Trend of using smart structures, that can adjust their behaviour when exposed to severe unexpected loading, is increasing. One of the methods to achieve such structures relies on smart materials. For example, replacing conventional steel reinforcing bars in Reinforced Concrete (RC) structures with superelastic Shape Memory Alloy (SMA) bars significantly limits the residual deformations caused by post-yielding behaviour. This paper provides in-depth understanding of the flexural behaviour of SMA RC beams. A sectional analysis method, that predicts the flexural behaviour of SMA RC beams during both loading and unloading stages, is adopted and validated using available experimental data. An extensive parametric study is then carried out to investigate the effect of different geometrical properties. Recommendations for the optimum amount and length of SMA bars are drawn based on results of this study.
Flexural Behaviour of Reinforced Concrete Beams Strengthened using Unbonded Superelastic Shape Memory Alloys Bars. (ST116)
Yamen Ibrahim Elbahy - University of Western Ontario
Strengthening Reinforced Concrete (RC) structures can be needed to upgrade their capacities and/or address deterioration happening overtime. Several strengthening techniques and materials are available in the market. In addition, ongoing research works on developing more innovative and cost effective techniques. In this study, a new technique for strengthening RC beams in flexure is introduced. The technique is based on using unbonded superleastic Shape Memory Alloy (SMA) bars. First, a Finite element (FE) model is developed using the ABAQUS software. After validating the model using available experimental results, the model is then used to capture the behaviour of the strengthened beams. A simplified sectional analysis approach is then presented as a much less complicated procedure of the analysis. After validating the simplified procedure, an extensive parametric study is carried out to investigate the optimum amount and length of the added SMA bars. Results of the parametric study are then used to develop equations that are capable of predicting the changes in the beam behaviour because of the suggested strengthening technique.
Flexural Behaviour of Reinforced Concrete Beam-Column Joints Strengthened Using External Superelastic Shape Memory Alloys Bars. (ST117)
Yamen Ibrahim Elbahy - University of Western Ontario
Pre-1970s designed and built reinforced concrete (RC) structures considered deficient to seismic loads. Beam-column joints (BCJs) of these structures are inadequately detailed in the joints areas. Thus, there is a need to strengthen these BCJs to cope with current design guidelines. In addition, BCJs of newly built structures may need to be strengthened due to change in the structure use or increase in the applied load level. In this study, the applicability of using external unbonded Shape Memory Alloys (SMAs) bars to strengthen RC BCJs is investigated. A finite elements (FE) model is first developed using the ABAQUS software. After validating the model with available experimental results, a simplified model is suggested to be used. A parametric study is then carried out to investigate the behaviour of strengthen RC BCJs.
Seismic Performance of Reinforced Concrete Frames Strengthened Using External Superelastic Shape Memory Alloys Bars (ST118)
Yamen Ibrahim Elbahy - University of Western Ontario
Pre-1970s designed and built reinforced concrete frame structures are considered unsafe when subjected to seismic loads. In addition, newly built frame structures are seismically designed for safety, where high inelastic deformations are allowed to occur under moderate to strong earthquakes. Minimizing these inelastic deformations make the structure repairable. One way to minimize these residual deformations is by using smart materials such as superelastic Shape Memory Alloys (SMAs). In this paper, the seismic performance of RC frames strengthened using external superleastic SMA bars is investigated and compared to the behaviour of a regular steel RC structure. A six storey RC frame structure is strengthened using external SMA bars. The frame is then subjected to different earthquake records at different intensities. The performance of the strengthened frame is compared to a regular steel RC frame in terms of the damage scheme, the Maximum Inter-storey Drift (MID) ratio, Maximum Residual Inter-storey Drift (MRID), and the roof drift ratio.
Innovative sludge disinfection approach to generate class A biosolids for land applications (EN27)
Jiaru Luo - Concordia University, Maria Elektorowicz - Concordia University
Wastewater treatment facilities generate a huge amount of sludge from their processes. One of the conventional methods for sludge management is the land application as a fertile soil amendment which is an efficient way to recycle nutrients from human waste. However, since sludge also contains pathogens, it is necessary to be disinfected before its usage. Then, a novel system has been demonstrated for sludge disinfection using a treatment supported by electrical field. This paper mainly focuses on optimization of the system to find out the best operating conditions for their further implementations. Investigation of Fe2+/H2O2 ratio, pH, current level, and amount of H2O2 were conducted to determine effective parameters for sludge disinfection through the Electro-Fenton method. The results showed log 7 reduction of E. coli within 30 minutes by applying selected parameters into sludge (WAS) in the electro-reactor.
Retrofitting Existing Educational Buildings in Egypt, DSM for Optimizing Energy Retrofit Strategies (GC58)
Rania Eltahan - The American University in Cairo, Ossama Hosny - AUC, Khaled Tarabieh - The American University in Cairo
The Energy dilemma is here to stay, this forced the decision makers to take economic considerations for upgrading their facilities, retrofitting vs. building new construction. For organizations which own a variety of buildings with limited resources for operation and retrofitting always faces the questions which building to start with and on what level.
Financial restraints, progressive demands for higher and extended level of service is widening operational challenges’. The main aim of facilities managers is maintaining a steady, attainable balance between the provided services’ portfolio and the incurred expenses, consequently, shifting towards retrofitting existing buildings is gaining a huge moment with its multitude of benefits among which energy cost reduction. This retrofitting always required extensive calculation and scenario modeling to attain the optimal state from an operational, ecological and financial perspectives.
This research presents a framework for developing a local decision support model that helps decision makers in Egypt to select the best and optimal scenario to retrofit existing buildings factoring in a predefined budget. This model provides a method to manage budget against proposed retrofits taking energy efficiency and return on investment into consideration.
The simulation model is being built using Designbuilder software which depends on different data categories collected from the building preliminary survey, retrofit decision scenario information from interviews with the operations team, energy bill readings, and the relevant building construction technical data. Twelve retrofit measures were assessed and utilized for the development of the Energy Retrofit Decision Support System (ERDSS) optimization model based on the proposed framework. Using LabVIEW software, the retrofit options are qualified, ranked and optimized according to the highest calculated savings to investments ratios where a case study has been selected from an educational institution at Cairo, Egypt.
The case study examines the applicability of ERDSS and functionality of the simulation model in the context of the budget constraints and technical limitations. An optimum retrofit scenario was recommended by ERDSS analysis, the model prioritized the possible retrofit actions within the allocated budget and according to savings to investment ratio results for each criterion. The results proved that the model delivered the expected output and provided the initially forecast plan.
Use of small-diameter round timber as structural members in light frame construction (ST107)
Wu Guofang - University of New Brunswick, Zhu Enchun - Harbin Institute of Technology, Ren Haiqing - Chinese Academy of Forestry, Meng Gong - University of New Brunswick
Small-diameter round timber is a kind of by-product mainly from the thinning operation of the plantations. It is a plentiful and inexpensive natural resource and is generally destined for non-structural applications such as pulp, boards or even fuels. Due to the small and varied diameter and irregularly curved axis of the timber, difficulties are confronted to process the small-diameter round timber into sawn lumber. In addition, there are also many challenges to develop efficient mechanical joints between roundwood members if they are directly used as roundwood. Thus the small-diameter round timber is rarely used as structural members in wood construction. This study was aimed to provide an innovative but simple way to use the small-diameter round timber as structural members. Three kinds of composite members were developed to be used in light frame wood construction, i.e. the built-up studs, the wood-steel joists, the wood-steel roof trusses, the shearwalls made of the developed built-up studs and the diaphragms made of the developed wood-steel joists. To facilitate the fabrication, the configuration of these members was described in a way to see the detail including the developed studs, joists, trusses, shearwalls and diaphragms. Efforts were also made to investigate the performances of these members, shearwalls and diaphragms via full-scale tests. It was found that the developed composite members could be used as substitutes of dimension lumber in the framework of light frame construction. The developed members could be also pre-fabricated as standard components in a mill and assembled on site. As a result, use of small-diameter round timber as structural members developed would be an efficient way to increase use of forest resource from plantation and lower the construction cost of light frame buildings.
Using sustainability cost curves to evaluate urban infrastructure in Canada (GC147)
Daniel Hoornweg - UOIT, Joel Thiebert - McKinsey, Michelle German - Evergreen, Mehdi Hosseini - UOIT, Jayne Engle - McConnell Foundation, Chris Kennedy - University of Victoria
Worldwide about $15 trillion is expected to be invested in urban infrastructure over the next 15 years. In Canada alone, the national government is investing $180 billion in infrastructure over the next 12 years. This increased investment is taking place while governments commit to reduce greenhouse gas (GHG) emissions and meet the Sustainable Development Goals (SDG). New engineering approaches, in addition to existing cost benefit analysis and factor of safety, are needed to broaden the assessment of urban infrastructure. This paper introduces sustainability cost curves as a means of ‘applied sustainable development’ to define and prioritize urban infrastructure. Sustainability cost curves rely on an open source sustainability assessment for the city or region. The sustainability assessment is dynamic and globally consistent, encompassing planetary boundaries, SDGs, urban resilience, and equity considerations. In this paper, sustainability assessments are provided for Montreal, Toronto and Vancouver.
The sustainability assessments facilitate the introduction of sustainability cost curves for transportation projects in Montreal, Toronto and Vancouver. The approach enables definition of sustainable (‘green’) infrastructure. We propose to begin this in Canada, with a view to launch the approach globally so that all major cities (urban regions) consider sustainability cost curves to better define urban infrastructure priorities and public policy options.
Alternative Interpretation of One-Way Shear Strength: Strain Penetration in Longitudinal Bar Anchorage (ST24)
Najmeh Eshghi - York University, Stavroula Pantazopoulou - York University
Significant effort has been vested over the years in quantifying the contribution of concrete to the shear strength of RC members. Design code expressions have been calibrated to a carefully assembled database of tests, where success of each design proposal is tested from its concurrence with the experimental sensitivities for the range of the design parameters, including size-related phenomena which are attributed to the brittle fracture of concrete. Recent advances in the study of bond and anchorage have provided insights into a totally new interpretation of shear failure. It is shown that strain penetration over the unconfined length, which spreads further into the anchorage with increasing moment at midspan, may propagate over the entire length of available longitudinal reinforcement, perpetrating brittle failure and collapse at loads that are much lower than the nominal shear strength. With this approach it is possible to reproduce successfully the experimental trends and to provide an alternative interpretation to the size effect which seems to be owing to the reduced bond strength of larger size bars in unconfined anchorages and the need for longer anchorage lengths - parameters that have not been accounted for in the past when calibrating shear models with test results. Examples from the experimental database of ACI 445 are solved using the mechanistic model for strain penetration in the shear span of a loaded beam; analytical estimates are calibrated against the test values. The significance of the work lies in the prospect it offers for a totally different look at shear design and the determination of the term for practical applications.
Compressive and Tensile Strength of Self Consolidating Concrete (SCC) Made with Copper Slag as Part of Cement (GC47)
Mostafa Fadaeefath Abadi - Concordia University, Zahra Mohammadi - Islamic Azad University, Kerman, Iran, Mohammad Javad Fadaee - Shahid Bahonar Univeristy, Kerman, Iran
Self-consolidating concrete (SCC) is a highly flowable concrete which doesn’t need any vibration and can fill the formworks automatically. It encapsulates areas with congested reinforcement. This phenomenon is nearly two-decade-old and with its special features, provides new possibilities to overcome problems resulted from the lack of proper density in concrete such as reduction of longevity and durability. Replacement of cement as the most expensive part of concrete with industrial materials such as slag, can reduce the cost and help to have a green construction industry. To have a sustainable development as well as enhanced performance and economy, alternative approaches such as using proper materials for replacement of cement should have been explored and studied by researchers. Recently, replacing ordinary cement with mixed cement due to the economic and environmental benefits has been increased.
This paper reports the results of an experimental study on the physical and chemical properties of the mineral complex copper slag as a by-product of Sarcheshmeh copper complex and its effect on the mechanical properties, including its compressive and tensile strength of SCC. At first, the physical and chemical analyses were performed on the slag and cement. In order to evaluate properties of SCC, several cylindrical samples with the diameter of 15cm and height of 30cm were manufactured. These samples had six level of substituting the cement by the copper slag. The substitution levels were fixed at 0%, 20%, 25%, 30%, 35% and 40%. The compressive strength test and also the Brazilian test, which is a test for indirect measurement of tensile strength, were performed on these SCC cylindrical samples. To achieve the optimum mix design with the most appropriate percentage of the copper slag the tests results were measured and determined at the age of 42 days. The Results showed that compressive and tensile strength of SCC with a specific amount of copper slag didn’t have a significant difference comparing to the SCC samples made without any slag. Therefore, this waste material can be introduced as a suitable alternative for part of cement in SCC. In other words, using SCC with industrial slag because of its characteristics could develop and improve the sustainability of concrete structures.
Flexural Resistance of TL-1 and TL-2 Concrete Bridge Barriers Using the Yield-Line Theory (ST22)
Morteza Fadaee - Ryerson University, Khaled Sennah - Ryerson University
Bridge barrier must be designed so that it could resist impact loads of crashes with different conditions. These conditions are defined in the bridge design codes such as the Canadian Highway Bridge Design Code (CHBDC), and classified into different test levels. Test levels 1 and 2 (TL-1 and TL-2) are defined for low volume road bridges with vehicles at the speed of 50 km/h, and consequences of vehicles leaving the roadway at the speed of 70 km/h, respectively. Based on these conditions, impact loads, barrier height and loads distribution length are provided in the code as well, and the barrier analysis and reinforcement design must be conducted using these specifications. Yield-Line theory is a method suggested in AASHTO LRFD Design Manual for bridge barriers. However, literature has shown the current triangular yield-line scheme provided in AASHTO is not accurate. The trapezoidal scheme provided in recent studies provides a lower flexural resistance. In this study, a modified trapezoidal scheme for yield-line analysis has been utilized for analyzing TL-1 and TL-2 bridge barriers. The analyze procedure includes calculation of various cases such as five different rebar spacing in both vertical and horizontal directions, interior and exterior locations of the barrier, and two cases of full height or top part of the barrier as part of the yield-line pattern. Finally, recommended barrier design and the impact resistance for each case have been provided.
Design of a High-Rise Building using BIM: A Capstone Course Project (GC169)
Safwan Khedr - The American University in Cairo, Ezzat Fahmy - The American University in Cairo, Ezzeldin Yazeed Sayed-Ahmed - The American University in Cairo, Sama Taha - The American University in Cairo, Ahmed Romaih - The American University in Cairo, Salma Mohamed Ibrahim - The American University in Cairo, Mina Naguib - American University in Cairo, Youssef Halabi - The American University in Cairo
This case study presents a graduation project of an undergraduate students group inthe American University in Cairo. In this project, complete structural and geotechnicalanalyses and design were performed for a high-rise building using BIM. It is the first timefor undergraduate students to develop a 3D building information model for a structure anduse it to generate an analytical model which is exported to ETABS for conducting structuralnumerical analysis followed by full design of the building structural elements andfoundation.The tower is 218 m high in which the architectural design requires a successive 2-degrees twist per floor through the building height resulting in a total twist of 80 degreesbetween the first and last floors. Furthermore, the architect also retracted the slabs every 6stories from a group of columns leaving 24 m high laterally unsupported edge columns. Assuch, the vertical and horizontal building irregularities present significant challenges in thestructural design and requires thorough structural particularly for seismic and wind analysesas well as the construction sequence. Due to the high water table at the building site,special dewatering technique was proposed along with the “full-tanking” designconsideration of the building basement.The BIM was first built on Revit, then the analytical model was developed. Thisanalytical model was imported to ETABS for numerically analyzing the tower. The towerwas designed as a reinforced concrete framed structure with shear walls according to ACI318M-14 provisions. The structural design was performed using ETABS as well as SAFE;the later was used to design the floor flat slabs of the tower. Geo5 was also used to designthe retaining walls in the basement considering the soil properties and the groundwatertable. Moreover, additional software such as STAAD and PCA columns were also used tovalidate ETABS’ outcomes. Finally, a 4D simulation model that shows the detailedschedule and construction process of the tower was performed on Navisworks.After many design iterations, all structural members of the tower were designed andthe students submitted complete structural drawings, a 3D BIM along with the 3D structuralnumerical model and full calculation sheets.
Integration of seismically induced site effects to the evaluation of the seismic vulnerability of bridges through a GIS platform (DM38)
Azarm Farzam - École de Technologie Supérieure, Nollet Marie-José - École de technologie supérieure, Amar Khaled - École de Technologie Supérieure
This paper proposes an approach to integrate seismically induced site effects to the evaluation of the seismic vulnerability of bridges through a GIS platform. The evaluation of the seismic vulnerability of bridges aims to assess the potential damage to structures in order to prioritize the interventions following an earthquake or to plan mitigation strategies. Evaluation procedures are generally index-based, and consider structural vulnerability and seismic hazard, which is usually defined in terms of the probable acceleration that could integrate the amplification effect of seismic waves by the site. A few index-based procedures take into account induced site effects, such as landslides, rock falls or soil liquefaction. Quantification of amplification and induced site effects requires site-specific geotechnical information. However, seismic risk assessment studies are usually performed on a regional scale for a large number of infrastructures scattered on a large territory. The lack of site-specific geotechnical information makes the evaluation of the seismic vulnerability of these infrastructures less representative. This study is based on the development of susceptibility scales to amplification effect, landslides, rock falls and soil liquefaction using geographical information systems (GIS). These susceptibility scales are defined documenting and characterizing the general context of geomorphology, geology and hydrography. The resulting susceptibility maps are then used to integrate susceptibility levels to seismically induced site effects into an index-based procedure for a better evaluation of the seismic risk of bridge networks.
Holistic Approach to Flood Risk Mitigation in Nova Scotia (DM9)
Victoria Fernandez - CBCL, Alexander Wilson - CBCL
The third United Nation World Conference on Disaster Risk Reduction recognized the importance of understanding disaster risks as result of the combination of not only natural hazards and infrastructure capacity but also social vulnerability, exposure levels, and emergency preparedness. Understanding these factors and their combined effect is fundamental for assessing risks, preventing disasters, mitigating damages and preparing for emergencies.
In the case of Canada flooding has been identified as the leading cause of emergencies. In this context, risk management requires not only understanding the hydrologic and hydraulic processes that result in extreme events but also recognizing that protection of infrastructure does not necessarily translate into the protection of public safety. In Atlantic Canada, more than 40% of residents live in rural and low budget communities. Populations at risks include First Nation communities and coastal settlements located in the Bay of Fundy (home to the highest tides in the world). Holistic flood risk management approaches in this region have focused on determining the priorities and needs of stakeholders, identifying vulnerabilities, evaluating the suitability of approaches such as retreat, protection and adaptation; and enhancing capacity for resilience. Complex computer modeling has also shown that the most effective approaches involve retreat, resilience, or other “soft” approaches to disaster management. The implementation of such approaches in Atlantic Canada needs to be placed in the context of limited budget availability, complex environmental settings, limited historical data and uncertain future climate.
In light of these limitations, emergency response management becomes key to the protection of life. For that reason, approaches such as flood forecasting are fundamental for enhancing resilience in Atlantic Canada. Flood forecasting allows real-time rainfall predictions and estimates of the potential distribution of runoff over a region. This approach has been implemented with success in Alberta, Manitoba, Ottawa, Ontario and the North. Flood forecasting in these areas has allowed government and emergency management agencies to issue flood warnings, operate gates and sluices, identify vulnerable areas and, when necessary, plan for evacuations.
This presentation aims to provide examples of holistic flood management approaches and softer flood mitigation techniques in the province of Nova Scotia. The discussion will also address the benefits, methodologies, and challenges for implementing flood forecasting programs to the local level in Nova Scotia and Atlantic Canada using calibrated hydrologic and hydraulic models and real-time rainfall forecasts from Environment Canada.
Performance-Based Wind Design of Tall Buildings (ST169)
Un Yong Jeong - Gradient Wind Engineering Inc., Kevin Tarrant - Gradient Wind Engineering Inc., Justin Ferraro - Gradient Wind Engineering Inc.
Tall buildings are vulnerable to wind loading, and their designs are therefore frequently governed by wind loads. ASCE 7 is also moving toward implementing performance-based wind design for buildings. This paper addresses basic issues in applying PBD to tall building wind design by investigating different characteristics between wind loading and seismic loading. The main differences lie in: i) probabilistic distribution of winds and ground accelerations, ii) aerodynamic effects such as vortex-shedding, and iii) substantially longer duration of wind loading compared to that of earth quake loading. Potential benefits of performance-based wind design were investigated by comparing wind loads with seismic loads for various return periods. In order to derive general discussions and conclusions, the study was applied to a generic tall building with a square plan dimension of 30 m by 30 m, and a building height of 300 m, leaving aspect ratio (slenderness ratio) of ten (10). The across-wind and along-wind loads and their responses were simulated for a range of return periods, covering service level, strength level, and collapse-prevention level events. Findings concluded that the ‘heavy-headed, light-tailed’ probabilistic distribution of wind speeds, singular building aerodynamic characteristics, as well as stiffness degradation due to long-duration wind loading should be properly addressed for successful implementation of PBD to tall building wind design.
Analytical Models for Recently Developed Beam-to-Column Connections in Moment Resisting Steel Frames (ST91)
Paul Steneker - McMaster University, Lydell Wiebe - McMaster University, Andre Filiatrault - University School of Advanced Studies IUSS
The investigations following the unacceptable performance of moment resisting frames (MRF) in the 1994 Northridge Earthquake identified issues in the weld detailing of beam-to-column connections used. These original MRF connections, commonly known as pre-Northridge connections, were identified as having a less ductile performance than anticipated. This conclusion led to the development of a variety of alternative connections with improved ductility. Research efforts immediately following the Northridge earthquake have resulted in the development of a variety of connections that are identified as pre-qualified by both United States (AISC) and Canadian (CISC) standards, allowing these connections to be selected by designers for implementation without the need for component-level validation. Some further research has resulted in a series of new MRF connections that allow for large inelastic behavior without the resulting damage due to plastic hinging in the beam. Connections such as the sliding hinge joint (SHJ) allow for large amounts of energy dissipation through friction of steel plates rather than plastic yielding. Modifications to this connection has resulted in a SHJ connection with self-centering behavior (SCSHJ).
This paper compares the behaviour of selected moment resisting connections, including pre-Northridge connections, currently pre-qualified connections, and newly developed low damage connections such as the SHJ and SCSHJ. For each type of connection, a non-linear model is developed using the OpenSees software based upon the available component test data. The calibration of these models is discussed, and the resulting parameters are summarized to allow both researchers and designers the ability to implement these connection elements quickly in numerical models of MRFs.
Assessment of costs of centralized and decentralized water systems on First Nations communities (EN24)
Timothy Vogel - University of Saskatchewan, Kerry McPhedran - University of Saskatchewan, Terry Fonstad - University of Saskatchewan, Rebecca Zagozewski - University of Saskatchewan
Water systems on First Nations are failing to consistently provide safe drinking water throughout Canada. Many of these communities have individual, household cisterns as part of a decentralized water system that are prone to contamination causing health issues. It has been suggested that there is insufficient funding provided by Indigenous and Northern Affairs Canada (INAC) for water infrastructure projects on First Nations which is preventing communities from addressing these issues that can be mitigated by moving to a safer, centralized distribution water system. Currently, the funding formula used by INAC focusses too simply on the construction costs of water infrastructure projects without considering human health related costs. This research examines the relevancy of the current funding formula’s indicators and expands the funding formula to include costs associated with health and social impacts that a decentralized distribution system has on a community. Communities with decentralized systems are facing costs associated with lost time due to illness, travel for medical care, and increased maintenance of water delivery trucks and access roads. Case studies were performed on Saskatchewan First Nations communities that have recently transitioned to a centralized distribution system to compare the actual project cost to what INAC would have provided using their funding formula. Other community case studies applied the updated funding formula showing the true cost of decentralized systems compared to the existing formula as justification for upgrading to centralized systems. The way funding is allocated to communities looking to upgrade and improve their water systems must be expanded to reflect long term impacts due to failing systems as justification for greater capital investment. This project will provide recommendations to update the funding formula including calculated actual human and social economic costs.
Estimating the Economic Feasibility of Biosolids Treatment by Smouldering (EN9)
Tarek Rashwan - The University of Western Ontario, Taryn Fournie - The University of Western Ontario, Gavin Grant - Savron, Jason Gerhard - The University of Western Ontario
Within wastewater treatment plants (WWTPs), approximately 50% of the operating expenses are associated with managing the solid by-product, biosolids, making it the most expensive component of the entire process. Managing biosolids is a major challenge, demanding complicated processing, expensive transportation, and wasteful disposal. The objective of this research is to investigate the economic feasibility of a new approach to managing biosolids that has potential to be more energy efficient and cost-effective than current disposal methods. Self-sustaining Treatment for Active Remediation applied ex-situ (STARx) was originally developed as a chemical waste management and soil-clean up technology. STARx is based on the concept of smouldering, a flameless form of combustion for solid and liquid fuels. Smouldering is thermally efficient, meaning the process can recycle much of the released reaction energy to destroy fuels containing little energy or significant moisture content (MC) that would otherwise not burn (e.g., via incineration). Previous research has demonstrated that up to 80% MC (wet mass basis) biosolids could be efficiently destroyed via smouldering. This is a key finding, as it suggests that this process can reduce the extensive processing (e.g., dewatering, thickening), which are significant WWTP expenditures. This research uses costs reported by the United States Environmental Protection Agency to estimate “target disposal costs” for retrofitting a STARx system into existing WWTPs that practice either land application or incineration. It was found that a target disposal cost within the range of $341-$823 per dry ton of biosolids is probably required to retrofit a wide range of WWTPs.
The calculation of the construction sites occupancy rate using the Chronographical modeling. (GC83)
Adel Francis - ETS, Stéphane Morin Pépin - École de Technologie Supérieure
Trying to increase stagnating, even regressing, productivity in the construction industry is as complex as trying to measure it and identifying the different factors that can influence it. Introduction of Building Information Modelling (BIM) has impacted the visualization and flow of information and forced the industry to review its management practices, methods, and techniques. BIM was originally intended for the design prospect. When applied to construction and operation phases, to produce 4D simulations, they require significant effort to revise the model and project schedule, particularly to characterize the spatial nature of projects. This is due to several factors, including limitations of scheduling techniques. In fact, these techniques either model a bar chart diagram that hardly represents spatiotemporal constraints or a linear diagram scheduling method that does not suit model building projects. Indeed, it is hard to show the work sequence, circulation and supply flow between the different zones on the construction project. The efficiency of Lean Manufacturing has attracted the construction industry’s attention, mainly to stabilize the workflow with TAKT-Time planning. The Last Planner system has also been developed with Lean Construction in mind and helped to create more realistic schedules by involving stakeholders or those in charge of carrying out the work. In order to develop adapted and more flexible models, Chronographical Modelling, based on space modeling concepts, aims to represent construction site flows and operations properly. Based on this model, the current paper proposes a new operation process that can facilitate 4D simulation. The process classifies and characterizes the different types of project stages, operations, flows, and spaces. Construction stages are divided into space creation, systems, divisions, finishing and closing space. The operation process and flow include repetitive, unique and spontaneous tasks. These tasks are sorted as exclusive or inclusive. Space occupations are allocated as spatial, linear and isolated, and zones are divided into floors, sectors, and exteriors. The model also considers the size and continuity of the teams as well as the occupancy rate of the site. Application of the model on a case study demonstrates its adaptability to 4D simulations.
Structural Fire Design in Canada using CSA S16 Annex K (ST155)
Matthew Smith - Entuitive, John Gales - York University, George Frater - Canadian Steel Construction Council
Canadian building structures are designed for a range of expected loads as prescribed by the building code, such as dead, live, wind, and seismic loading. Building structures are not explicitly designed for extreme loads such as fire and blast except for robustness clauses in material design standards and the prescriptive fire safety strategy described by the building code. Using performance-based approaches is becoming increasingly important as the value of the operation within buildings greatly exceeds the value of the building itself and engineers seek to quantify structural performance for a range of extreme events.
This paper discusses fire as a load case on structures as described in Annex K of CSA S16-14, “Structural Design for Fire Conditions”. The Annex is a normative (mandatory) part of the steel design standard, which can be applied to the structural fire design of steel and composite-steel buildings. To perform a structural fire design, the engineer requires an understanding of the design fires, the material behaviour at elevated temperature, a load combination to apply the fire exposure, tools to determine the loading and deformation imposed by the fire, and finally acceptance criteria to assess the structure. Annex K describes all of the above for the Canadian practitioner as provided in this study.
The study introduces Canadian case studies that use Annex K for a structural fire design, which would be an engineered “alternative solution” under Canada’s objective-based building code. This contrasts with an “acceptable solution” which incorporates fire-rated assemblies tested as per CAN/ULC S101. Annex K to date has seen marginal impact on the fire safety of structures largely because it is relatively new, and has yet to be communicated effectively to practitioners - this research study's novelty is that it addresses this by demonstrating its benefits for the designer. The case studies include both simple and advanced methods of analysis. In terms of advanced analyses, the authors introduce the slab panel method as well as finite-element modeling of entire floors, both utilizing tensile membrane action in a Canadian context. The advanced methods of analysis allow engineers to quantify performance for a range of fire events and their impact on the operations within the structure. Canadian practitioners and educators will benefit from this study’s overview of possible structural fire designs and their benefits, while authorities will be introduced to performance-based approaches that are being proposed on contemporary Canadian structures with increasing frequency.
Ultraviolet Light Emitting Diodes (UV LEDs) for Biofilm Control (EN26)
Stephanie Gora - Dalhousie University, Kyle Rauch - Dalhousie University, Carolina Ontiveros - Dalhousie University, Graham Gagnon - Dalhousie University
Biofilms consist of microorganisms and extracellular polymeric substances attached to a surface. In the drinking water industry, biofilm growth on treatment equipment and biofilm formation in drinking water distribution systems are major ongoing challenges. Control mechanisms include flushing, chemically intensive cleaning procedures, chlorination, and the removal of water matrix components that encourage the growth of biofilm-forming bacteria (e.g. natural organic matter). These procedures can be onerous and shorten the useful lifetime of the equipment and there is demand for novel disinfection technologies that can provide fast and effective disinfection without damaging equipment or infrastructure. Germicidal ultraviolet violet (UV) light is one potential option for these applications, and UV light emitting diodes (UV LEDs), which are smaller and more energy efficient than standard mercury UV lamps, are particularly promising.
In this study, Pseudomonas aeruginosa biofilms were grown on plastic, glass, and aluminum coupons and exposed to UV LEDs emitting light at 265 nm for times ranging from 1 to 60 minutes. The biomass remaining on the coupons was then dissolved in sterile phosphate buffered solution, which was then plated on tryptic soy agar to determine colony forming units and analyzed for adenosine triphosphate (ATP) concentration, a quick and effective measure of biological activity. Preliminary results indicate that 3 log inactivation was achieved after 30 minutes (UV dose = 62.5 mJ/cm2) and 7 log inactivation was achieved after 60 minutes of irradiation (UV dose = 125 mJ/cm2). These doses are higher than those reported for planktonic bacteria (Beck et al., 2017) but comparable to those required to inactivate Pseudomonas aeruginosa in biofilms in medical applications (Bak et al., 2010).
The results of this study indicate that UV LED irradiation is a viable technology for surface disinfection. These findings have implications for the drinking water industry and for other industries that struggle to control biofilm growth. Future experiments will compare UV LED disinfection to standard biofilm mitigation strategies for water treatment equipment and water distribution infrastructure.
Bak, J., Ladefoged, S.D., Tvede, M., Begovic, T., Gregersen, A., 2010. Disinfection of Pseudomonas aeruginosa biofilm contaminated tube lumens with ultraviolet C light emitting diodes. Biofouling 26, 31–38. doi:10.1080/08927010903191353
Beck, S.E., Ryu, H., Boczek, L.A., Cashdollar, J.L., Jeanis, K.M., Rosenblum, J.S., Lawal, O.R., Linden, K.G., 2017. Evaluating UV-C LED disinfection performance and investigating potential dual-wavelength synergy. Water Res. 109, 207–216. doi:10.1016/j.watres.2016.11.024
Life time prediction for bituminous mixtures with low energy and ecological effects (MA35)
Maria Inmaculada García Hernández - Wuhan University of Technology
Road surfaces with low temperature bitumen are usually used due to the lower energy consumption and environmental considerations.
This paper presents a study of the performance of low temperature bitumen, in particular, the long-term behavior and life-time prediction of some low-temperature bitumen. Six bitumen mixture samples were tested with different modifiers such as synthetic Cecabase (C), Sasobit (S), Greenseal (G) and Advera (A) wax. Pavement performance prediction in terms of fatigue cracking and surface rutting is essential for any mechanistically-based pavement design method. In this study full-scale Accelerated Pavement Testing (APT) has been used to simulate field conditions and Equivalent Standard Axles (ESAs). Fatigue response was also analyzed in the laboratory. This paper focus on developing a life time prediction model based on rutting and fatigue to describe the stable and unstable performance of six tested low energy bitumen mixtures.
Physical and Mechanical Properties of Flax-Lime Concrete (MA18)
Krishna Priyanka Garikapati - Dalhousie University, Pedram Sadeghian - Dalhousie University
Due to increase in production of construction materials, the emission of carbon dioxide and requirement for using materials with less environmental foot print is gaining more attention. One of the solution is to replace high carbon dioxide emitting construction materials with plant-based materials. This paper involves study of physical and mechanical properties of flax-lime concrete, which is a mixture of flax shives and lime-based binder. The main aim of this research is to use flax-lime concrete as an insulation material especially in the wall cavities of buildings instead of synthetic insulation materials. As flax is obtained from the plant it has the capacity to absorb carbon dioxide which is an added advantage. Also, replacing cement with lime reduces large amount of carbon dioxide associated with cement production. In addition, flax shives are by-product of extracting long flax fibers in textile industry. Since, insulation material does not require high strength, flax shives are considered in this research. Lime also adds value to moisture resistance properties of the product. Different proportions of flax shives (10 mm long), hydrated lime, Portland cement, and water are under evaluation to reach the best mix deign. Compaction procedure is also adjusted to reach desirable density and compressive strength. This research is still in-progress and more results will be included in the full paper.
Predicting the Capacity of Aluminum Compression Members With Complex Cross Sections (ST145)
Scott Walbridge - University of Waterloo, Laurent Gérin - University of Waterloo
The purpose of this paper is to present the results for buckling tests for aluminum compression members with two cross section geometries and three lengths, and compare the results with predictions based on several design codes and results from 3D nonlinear finite element analyses (FEA). The cross section geometries consist of a rectangular hollow structural section (HSS) member, with a single slot running the length of the member at two different locations, resulting in different local buckling capacities for the different plate elements in the cross section. The tested geometry was designed to represent the more complex extrusion shapes that are possible and commonly seen in aluminum structures. The results show varying degrees of conservatism in the investigated design codes. The FEA procedure employed general does a good job of predicting the test results. The accuracy of this procedure could likely be further improved with more careful measurement of the material strength, initial imperfection geometry, and boundary conditions. Other recommended areas for future work include looking at a broader range of compression member lengths, cross section geometries, and aluminum alloys.
Comparison of Different Accelerated Corrosion Techniques (MA29)
Mahmoud Said - Memorial University of Newfoundland, Amgad Hussein - Memorial University of Newfoundland, Assem Hassan - Memorial University of Newfoundland, Nick Gillis - SNC Lavalin Inc, Canada
This paper presents different techniques that could be used in conducting an accelerated corrosion experiments in a lab environment. The objective of the techniques is to induce corrosion in full-scale structural reinforced concrete members. The study aims to demonstrate the benefits and drawbacks of each technique. Two full scale reinforced concrete two-way slabs were prepared for this experiment. The slabs had an identical dimension of 1900 mm × 1900 mm × 150 mm. The slabs reached the same level of corrosion, 25% mass loss, using two different accelerated methods: constant voltage and constant current. The induced corrosion in each slab was evaluated. The corrosion state was examined based on current measurement, half-cell potential tests, and mass loss. Both techniques showed a close agreement between the actual mass loss and the theoretical mass loss that was calculated using Faraday’s equation. During corrosion, the concrete loses its resistivity which is directly reflected by an increase in the current in the case of constant voltage. Hence, using constant voltage could cause damage more than that by normal environmental conditions. Whereas constant current technique keeps the current intensity uniform over the corrosion process regardless of the resistivity of concrete, leading to uniform corrosion rate which avoid extreme damage.
Productivity Modeling for Quantifying Cumulative Impact of Change orders (GC163)
Sasan Golnaraghi - Concordia University, Zahra Zangenehmadar - Concordia University, Roghabadi Mohammadjavad - Concordia University, Abbas Yeganeh - Iran University of Science and Technology
In labor-intensive construction projects, labor costs are a substantial percentage of the total budget for construction projects. Thus, understanding labor productivity is essential to project success. If productivity is impacted by any reasons such as the extensive number of changes or poor managerial policies, project labor costs will increase over and above the overall project total costs. Changes are considered as the integral part of construction projects by researchers and industry practitioners and their cumulative impact should not be overlooked since it can be detrimental to a project success. Although the measured mile method is well known and widely accepted for quantifying the cumulative impact of changes on labor productivity, it is not easily applicable to many cases. It is difficult to identify and measure this impact on the mentioned productivity. Hence, modeling labor productivity using different techniques are becoming more desirable. It is a challenging task as it requires identification and quantification of the influencing factors on labor productivity and considering the interdependencies among those factors. In this paper, three regression methods of Best Subset, Stepwise, and Evolutionary Polynomial Regression (EPR) are used to model the labor productivity. The dataset used in modeling the labor productivity in this research has been gathered by Khan (2005) from formwork installation of two high-rise buildings in the downtown of Montreal. The best model will be selected based on statistical performance indicators. The model has a potential to be used for quantifying unimpacted productivity which later can be used for implementing measured mile method. Results show that the developed model through EPR has the best performance, however, expert’s judgment and preprocessing are necessary to modify the model and prepare it for construction practices in evaluating the cumulative impact of changes on labor productivity.
Development of Lightweight Overlaid Laminated Bamboo Lumber for Structural Applications (ST108)
Xin Guan - Fujian Agriculture and Forestry University, Meng Gong - University of New Brunswick, Qirong Wu - Fujian Agriculture and Forestry University
The overlaid laminated bamboo lumber (OLBL) was developed for structural applications with an aim to substitute commonly-used building materials such as steel and concrete. The OLBL was, via a hot press, fabricated by cross-laminating bamboo layers, bamboo mats and phenolic impregnated adhesive papers. Since the weight of OLBL was governed by the high density bamboo layer, the panels made of OLBL had a relatively high density value of about 850 kg/m3. In this study, a lightweight panel was developed by a proper arrangement of radial bamboo curtain. The major and minor directions of a panel were the parallel- and perpendicular-to-its length direction, respectively. It was found that 1) the density of an OLBL panel could be reduced by about 20%; 2) the failure occurred in the bamboo node(s); 3) there was a significant difference in modulus of elasticity and modulus of rupture between two panel directions; and 4) there was a good relationship between the density and strength in the minor direction.
Debris Damming Loads and Effects in Tsunami-Like Events (DM1)
Jacob Stolle - University of Ottawa, Ioan Nistor - University of Ottawa, Nils Goseberg - Leibniz Universitat Hannover, Emil Petriu - University of Ottawa, Tomoyuki Takabatake - Waseda University, Tomoya Shibayama - Waseda University
Throughout Canada’s history, its coastlines have been often struck by tsunamis, though few have been large enough in recent history to cause significant damage. However, the proximity of the Canadian West Coast to the seismically active Pacific Ocean “Ring of Fire” makes this area vulnerable to tsunamis. Recent major tsunamis which occurred recently in other areas of the world, such as the 2011 Tohoku Tsunami (Japan), highlighted the challenges associated with adequately and economically designing coastal infrastructure to protect or withstand such extreme events. One of these challenges includes identifying and quantifying the critical loading conditions for infrastructure that could occur in such events. Field surveys of the 2011 Tohoku Tsunami, as well as in forensic engineering surveys of other major flooding events, identified debris damming as one of these critical loads. Debris damming occurs when solid objects form dams or obstructions on the face of structures, resulting in increased drag forces acting on the structure. This phenomenon can be particularly damaging when breakaway walls or structural porosity have been relied upon to reduce the drag loads.
The study presented herein will examine the debris damming loads in a laboratory setting. The experiments examined the formation, loading, and wave runup on a generic structure under unsteady flow conditions. A bore was generated using a rapidly opening sluice gate to release a static water column. The debris were scaled-down (1:50) solid objects, modelled after common debris observed in videos of the 2011 Tohoku Tsunami: shipping containers, hydro poles, and construction debris. The debris were placed on the bed of the flume and allowed to freely propagate towards a structure to form the dam. Analysis of the experimental results showed that the wave runup could be approximated assuming hydrostatic pressure at the face of the dam. Additionally, the occurrence of the maximum drag force tended to occur at a different stage of the bore development for the case with debris damming as opposed to no debris, tending towards increased loading during the high-velocity stage.
Monitoring and Evaluation of Pedestrian Induced Vibrations (ST158)
Niel Van Engelen - University of Windsor, Julia Graham - RWDI Inc.
Vibrations due to pedestrian footfalls are often the governing source of vibration on the upper floors of structures. These vibrations may cause discomfort for occupants, or interfere with the operation of sensitive equipment in structures such as research and healthcare facilities. A conflicting trend in structural engineering has emerged. Structural designs have progressed towards longer spans with efficient designs that are increasingly flexible, rendering them more susceptible to pedestrian-induced vibrations. Meanwhile, the vibration targets of high precision equipment, such as CT scanners and MRIs, have become increasingly stringent. Mitigating pedestrian-induced vibrations often results in considerable re-design of the structure to obtain a sufficiently stiff and massive floor, particularly in applications with sensitive equipment. Design guidelines assist structural engineers in achieving vibration performance objectives based on discrete walking speeds or a range of walking speeds. Long-term vibration measurements were undertaken in an office setting. Statistical analysis is applied to compare the long-term vibration performance of the floor against existing methods of predicting floor response due to pedestrian-induced vibrations and field measurements taken by an engineer used to evaluate the performance. The analysis is used to evaluate the accuracy of the predicted vibration performance and the field measurements in comparison to regular vibration performance.
Important Factors Related to Increasing Cycling in Cities (TR22)
Danny Haines - University of Calgary, Farnaz Sadeghpour - University of Calgary
Cities around the world are looking for ways to increase the share of travellers who use active transportation modes. Active transport is more cost effective than traditional vehicular infrastructure and also offers significant health benefits. Despite these benefits, the relative newness and unfamiliarity of cycling as a mode of transportation means that cities must find ways to optimize investment to most efficiently increase ridership. It is important for city planners to know what types of infrastructure potential cyclists are interested in. They should also be aware of the barriers to cycling that people perceive as being most important so that these can be mitigated. The objective of this study is to determine what factors are related to increased ridership of bicycles. To this end, an intercept survey was completed to collect the opinions of 189 people in Calgary. In addition to basic demographic information, the survey collected data about respondents’ current cycling habits and their opinions on various items related to increasing or decreasing their propensity to ride. Using inferential statistics, respondents’ opinions were correlated to the various demographic and baseline cycling characteristics to find patterns. The correlations make suggestions about where cycling infrastructure dollars could be best spent to achieve the goal of increased cycling ridership. The findings of this study can be used by transportation planners to more efficiently allocate transportation spending. This in turn could lead to increased ridership, lower costs to taxpayers, and greater health benefits for users.
Feasibility of Lump Sum Contracts in the Oil and Gas Industry of Alberta (GC102)
Danny Haines - University of Calgary, Farnaz Sadeghpour - University of Calgary, Jacqueline O'Toole - Husky, George Jergeas - University of Calgary
Construction in the Alberta oil and gas industry experiences particularly substantial schedule and cost overruns. Cost overruns on large Alberta-based projects have been found to be, on average, 533 percent higher than similar projects executed in the United States. Previous studies show that the use of lump sum contracts can have a considerable impact on controlling costs. However, most construction projects in Alberta’s oil and gas industry use cost reimbursable contracts. Considering the cost controlling qualities of lump sum contracts, it is unclear why they are under-utilized in Alberta. nt investigated significantly in Alberta. well-accepted means of controlling cost but is A better understanding of industry practitioner’s perceptions can enable a successful shift to lump sum contracts which could translate into increased cost and schedule predictability of oil and gas projects. The objective of this study is to determine the interest of industry practitioners in using lump sum contracts for oil and gas projects in Alberta, and also their perceptions of the barriers to its implementation. A total of 240 industry practitioners from Alberta were surveyed for this study, representing the perspectives of owner, engineer and contracting companies. Respondents had an average of 19 years of experience. Descriptive statistics of the respondent’s opinions are presented. The responses are then analyzed for correlation using inferential statistics. The results push forth the idea that lump sum contracting is best suited for use at distinct phases of project execution. The study also details the most significant barriers that practitioners believe will have to be overcome before lump sum contracting can be accepted in Alberta’s oil and gas industry. Results from this study provide an insight into practitioner’s assessments of the industry and can be used as a first step in preparing companies and industry as a whole to make the shift to lump sum in Alberta. These findings could thus improve the cost and schedule performance of construction projects in the oil and gas industry of Alberta.
Automatic calibration tool for 2D hydrodynamics modeling (GC57)
Nadia Hajjout - École Polytechnique de Montréal, Mahdi Tew-Fik - École Polytechnique de Montréal, Département des génies civil, géologique et des mines (CGM)
The roughness of a river and its floodplains, represented by Manning's coefficient is one of the major parameters that is unknown during river modeling. Thus, suggesting accurate Manning`s coefficients requires an extensive model calibration. Since manual fitting method can be very tedious, complex and time consuming, automatic calibration is well suited for complex river models. This paper presents an updated automatic calibration tool, O.P.P.S_V2, compatible with version 3 of the hydrodynamical software SRH-2D. O.P.P.S_V2 is completely autonomous and gives the best parameter values for which the difference between model-generated and measured observations is minimum. The calibration tool uses the software PEST, Parameter ESTimation, to fit roughness coefficients. For test and verification purposes, O.P.P.S_V2 is used to estimate Manning’s coefficients for an experimental data set of a laboratory 2D flow. For comparison purposes, Manning’s coefficients are estimated using both the direct step method and automatic calibration. The model responded well to the automatic calibration of Manning’s roughness coefficient, computing a coefficient very similar to the one suggested by the theory.
Improving Conveyance Side Slipper Plate Design to Accommodate Higher Impact Bunton Force (ST49)
Maykel Hanna - Stantec consulting Ltd, Alan Lloyd - University of New Brunswick, Timo Tikka - Stantec Consulting
The demand on mine conveyances is increasing as material is being transported to the surface in larger quantities than ever. Mines require higher mass conveyances moving with higher hoisting speeds. Both contribute to potentially higher lateral impact forces (slam loads) from the conveyance onto the fixed guide system at the slipper location. The magnitude of these slam loads needs to be reduced to mitigate potential damage to the guide rail system and allow continuous operation of mines. This research examined the behavior of Cotton Duck Pads (CDP), a type of elastomeric bearing pads, under impact load to be used to reduce the slam loads exercised on mine guide system. Unlike traditional bearing pads, CDP, in this case, will not carry large gravity loads but it will carry dynamic loads including cyclic and extreme rare impact loads.
Due to the lack of information on the behavior of CDP under high strain rates, 52 specimens were tested to study the CDP behavior under strain rates of 0.001 to 200s -1. The tests were conducted using a Universal Compression Testing Machine (UCTM) for low strain rates and a modified Charpy machine for high strain rates. Load cells and accelerometer were used to measure the testing forces. Linear variable differential transformers (LVDTs) were used to measure the displacement in UCTM test. A high-speed camera captured images to conduct a digital image correlation (DIC) analysis for the modified Charpy machine test to measure the specimens’ deflections. This research had, also, examined the dynamic behavior of conveyances using Comro design guideline (1990) and compared it against single degree of freedom analysis (SDOF) using Newmark’s method.
The data, collected during different tests, were used to present stress-strain curves of CDP to be used in the dynamic analysis. The stress-strain curves were simplified by second-degree curves. These curves were used to study the conveyance dynamic behavior with a CDP installed at the slipper location. To simplify the conveyances dynamic analysis, secant value of modulus of elasticity (300-400 MPa) could be added to design practice. This research will present a full design guideline for designing bearing pads used to reduce rare and extreme impact loads in a mineshaft. The system is designed for installation in both old and new mine conveyance systems using fixed guide systems.
Can we better leverage national data collection initiatives to support transportation planning in smaller cities and rural areas in Canada? A view from New Brunswick (TR43)
Trevor Hanson - University of New Brunswick
As Canada’s population ages, there will be growing calls for transportation solutions that address the challenges associated with transportation and aging, in particular, for those who are unable to drive. Effective transportation solutions require a clear understanding of travel behaviour, yet the most sophisticated transportation studies are undertaken in the largest urban centres where many alternatives to driving already exist. Smaller cities and rural areas are among the most rapidly aging in the country, yet may not have the resources to conduct studies to understand the travel needs of their residents, necessitating reliance on national datasets. National datasets, such as the Census, can be used to gain some insight into broad travel needs, but are limited in terms of specific conclusions that could be used to support transportation solutions for non-driving older adults.
This paper profiles national Canadian data collection efforts in terms of their suitability and limitations to be used for transportation planning in smaller communities, with a New Brunswick focus. The paper identifies opportunities to consider new questions or wording among these national surveys that could provide an additional resource for smaller cities and rural areas to help support their transportation planning for an aging population.
The Deterioration of Pavement Marking Retroreflectivity: Are We Ready to Adopt Minimum Standards? (TR45)
Carly MacEacheron - WSP, Eric Hildebrand - University of New Brunswick, Trevor Hanson - University of New Brunswick
Pavement markings with retroreflective properties provide delineation and safety benefits for drivers during nighttime conditions. Many road authorities do not have a history of retroreflectivity performance for pavement markings throughout their life-cycles. This makes it difficult to assess the impacts of potential minimum retroreflectivity standards such as those proposed by the Federal Highway Administration (FHWA) or to adopt performance-based specifications. A year-long study of pavement markings on 24 sampled road sections was performed to better understand the state of pavement markings in New Brunswick and the causes/rates of their deterioration. Analyses found the factors that have a statistically significant effect on pavement marking retroreflectivity include age, traffic volume, road class, season when the marking was applied, and paint colour. Analyses of the sampled retroreflectivity values found that they generally deteriorate over time, and that white markings consistently produce higher readings than yellow markings through their life-cycle even though white markings deteriorate more quickly. Overall, 27% and 38% of sampled pavement markings met the 2014 or 2017 proposed FHWA minimum retroreflectivity standards at the time of their replacement, respectively. These findings suggest that the current pavement marking maintenance schedule used in New Brunswick (which is consistent with many other jurisdictions) would be inadequate if minimum standards consistent with the FHWA were to be adopted. It is recommended that road authorities develop pavement marking policies that will improve compliance with an adopted set of minimum retroreflectivity standards or guidelines.
The future of Building Foundations in the Canadian North (GC112)
Christine Harries - SNC-Lavalin
The Canadian North is experiencing several building engineering problems which must be addressed now to avoid worsening problems in the future. The permafrost layer is retreating downward in the Canadian North. This is resulting in many unstable homes in the 14 villages of Quebec`s Nunavik. Current tripod adjustable footings, while the most popular, are not the way of the future. Several other methods such as concrete footings on bedrock, or on deep permafrost, exist. When bedrock is very deep, steel piles represent a good way to stabilize buildings. Some cases require add freeze piles when bedrock is too deep to reach economically. Lattice truss systems on tripod footings have also been used. This report explores the most prominent solutions of the future and reinforces which methods are believed to best perform going forward.
Preliminary design of a TMD with a liquid-based damping system for building motion control in wind (ST72)
Chien-Shen (Tom) Lee - RWDI Inc., Shayne Love - RWDI Inc., Trevor Haskett - RWDI Inc.
Supplementary Damping Systems (SDS), such as tuned mass dampers (TMDs), tuned sloshing dampers (TSDs) - also known as tuned liquid dampers (TLDs) - and tuned liquid column dampers (TLCDs) have been successfully employed to reduce building motion during wind events by dissipating the vibrational energy of the building. A TMD generally consists of a mass, a stiffness system and a damping system (traditionally linear or nonlinear dashpots) that dissipates energy. Optimal design of the mass, stiffness, and damping system is critical for a TMD to have best performance. Some practical design challenges for a TMD damping system include heat management, space allocation, and frictional forces. While heat and friction are not concerns for a TSD, a TSD usually requires more space than a TMD. A novel type of TMD is investigated, which consists of a TMD with a liquid-based damping system; a TMD using a TSD as its damping system, to integrate the advantages of a TMD and a TSD into one system. A model is developed to investigate the proposed system. Simple expressions for the optimal TSD mass, tuning ratio, and liquid damping ratios are employed to optimize the novel TMD coupled to a single degree of freedom structure. A design example of the TMD with a liquid-based damping system is presented and compared to a conventional TMD design. The proposed TMD with a liquid-based damping system is shown to be an efficient and affordable device for controlling building motion.
Influence of Shape and Casting Direction on ASR Expansion (MA48)
Sameh Hassan - Concordia University, Ahmed Soliman - Concordia University, Michelle Nokken - Concordia University
Alkali-silica reaction is a prevalent type of deterioration in concrete infrastructure. In laboratory testing, prisms are cast horizontally and subsequently tested for expansion in the vertical direction. This may not adequately relate to actual cast-in-place concrete structures. In this research, both prisms and cylinders were cast in horizontal and vertical directions. Both axial and transverse expansions were measured. Spratt aggregate and fused silica were used to hasten reaction to better observe the influence of shape and casting direction. Results showed significant differences with prisms exhibiting more expansion than cylinders. The horizontal casting was seen to influence the measured expansion. The transverse expansion was observed to be higher for the cylinders cast in the horizontal direction.
Electrical Resistivity, Absorption and Mechanical Properties of Rubberized Concrete (MA49)
Sameh Hassan - Concordia University, Ahmed Soliman - Concordia University, Michelle Nokken - Concordia University
The application of crumb rubber from recycled tires has been used in construction as a replacement from the aggregate and fine sand in concrete. The use of these materials can improve the concrete performance and may enhance its properties, in addition to minimizing the cost. This paper investigates the effect of 10% replacement of sand with fine crumb rubber on properties of concrete mixtures with and without silica fume. Compressive and tensile strengths, stiffness damage test, surface resistivity, bulk resistivity, sorptivity and rapid chloride penetration tests were conducted. Results showed that the use of rubber without silica fume decreases the mechanical properties compared to the plain concrete, while it enhances concrete modulus. In addition, rubber had a marginal effect on the relationship between concrete mechanical properties and electric resistivity. Moreover, the use of rubber with silica fume had a significant effect on the hydraulic properties.
Estimating impact forces of falling objects in mine shafts (ST3)
Helmut M. Haydl - Redpath Canada Limited
Miners working in mine shafts have to be protected from objects that can fall and cause injuries. Falling object protective structures (FOPS) such as bulkheads, structural enclosures and canopies are commonly constructed in the mining industry as protection. The design of these structures is challenging since one of the main design parameters, namely the magnitude of the load imposed on the structure, is unknown and has to be estimated. Therefore, the most difficult assumption is the determination of what is falling down the shaft. To aid in this, the designer has to rely heavily on information from site and the past experience of mine personnel. There is limited information available in the published literature on falling rock impacting part of a protective structure or impacting a rock surface at shaft bottom. The estimation of the impact force is the important element of any rational design. A simple procedure based on energy balances principles is presented in the present paper. The proposed method includes consideration of fragmentation of the impacting rock. Some of the limiting parameters are based on published experimental work of others, but are applied to practical design of some examples. It is suggested that a rational design criteria for FOPS should be based on the energy level at impact, instead of the customary factors of safety. Since the safety aspect of these types of structures is very important, the level of risk to prevent injuries to miners should be a main consideration in design.
Evaluating the Effects of Mineral Filler on the Volumetric Properties of HMA Mixtures Based on Superpave Mix Design Specifications (MA77)
Vimy Henderson - CPATT - University of Waterloo, Susan Tighe - CPATT - University of Waterloo
Volumetric properties of hot mix asphalt (HMA) are necessary requirements to ensure good performance for asphalt mixtures. However, volumetric properties appear to be directly influenced by various factors including the mixture grading, aggregate surface characteristics, and compaction energy. This research is conducted to evaluate the influence of mineral filler on the volumetric properties of HMA. Two types of mineral fillers with three filler percentages were chosen to examine the effect of filler on various volumetric properties including voids in mineral aggregates (VMA), voids filled with asphalt (VFA), dust to binder ratio (Dp), and others. The obtained results indicated that the optimum asphalt binder content, VMA, and VFA decrease as the filler content is increased. Compared to other volumetric properties that were reduced when filler content increased, Dp proportion behaved inversely for both filler types in which Dp proportion increases when the filler content is increased. HMA mixtures that include dust plant filler had the higher values of VMA, VFA, and optimum asphalt content (OAC) compared to the hydrated lime. The addition of filler with 2.5% percentage is very successful for both filler types due to satisfying all Ministry of Transportation Ontario (MTO) requirements for volumetric properties of HMA. Based on MTO specifications, the addition of 2.0% filler seems to be unsuccessful for both filler types due to lowering the Dp ratio. Mix design with 3.0% filler was also unsuccessful because of the lower value of OAC meaning that the mix is dry and there is insufficient asphalt binder to coat the aggregate particles.
Investigation of Treated CRCA in HMA Mixtures through Evaluating Low Temperature Cracking (MA36)
Vimy Henderson - CPATT - University of Waterloo, Susan Tighe - CPATT - University of Waterloo
One of the most widespread concerns of asphalt concrete pavement in cold-regions of the world is thermal cracks or low-temperature cracks. The reason behind the initiation of the thermal cracks is mainly attributed to the development of stresses which exceed the pavement strength, that leads to pavement cracking at extremely low temperatures. In this research, the influence of coarse recycled concrete aggregate (CRCA) addition on the behavior of asphalt mixtures at low temperatures. To evaluate the performance at low temperatures, thermal stress restrained specimen test (TSRST) is performed to assess the influence of (CRCA) addition into asphalt mixtures based on Ontario Superpave specifications. The effect of different CRCA types with various proportions on the fracture stress and fracture temperature of the asphalt mixtures is also examined. To achieve the objective, two different types of CRCA with various percentages (0%, 15%, and 30%) were chosen. The impact of treated CRCA on the behavior of asphalt mixtures at low temperatures is further evaluated. To achieve this goal, the application of the combination of various treatment methods is utilized for treating CRCA. Heat treatment at 300C and followed by a short mechanical treatment is applied to enhance physical and mechanical properties of CRCA. The obtained results indicated that there is a considerable improvement in thermal cracking resistance of HMA through the combination of heat treatment and short mechanical treatment. The findings results revealed that there is no considerable influence on the type of CRCA on the fracture temperature of HMA mixtures.
Keywords: Asphalt concrete mixtures, Recycled concrete aggregate (RCA), Low-temperature cracking, Thermal Stress Restrained Specimen Test (TSRST), Heat treatment.
Case Study: Chignecto Ship Railway (GC183)
Bruce Higgins - CBCL Limited
The site of the Chignecto Ship Railway was designated as a national civil engineering historic site by the Canadian Society for Civil Engineering (CSCE) in 1989. While CSCE has made effort to designate many historic sites across Canada, these accomplishments are not well known amongst engineers and the general public. The purpose of this case study is to provide insight into this project, and thereby promote more interest in it and civil engineering history in general. It is also intended that this will help promote engineering history as a regular session at annual CSCE conferences.
The topic is meant to have a general appeal to civil engineers, particularly with regard to history, heavy civil construction, transportation and the allure of visionary mega-projects. The 27 km long project is located in Nova Scotia, but immediately adjacent the New Brunswick border.
The approach is to briefly explore the engineer and his dream, followed by the construction, associated problems and aftermath.
Cracking Behavior of Base-Restrained Reinforced Concrete Walls under Temperature and Shrinkage Strains (ST100)
Ahmad Hooshmand - Ryerson University, M. Reza Kianoush - Ryerson University
The issue of crack control in reinforced concrete members has been the subject of research for decades. However, crack formation still cause serious damages in reinforced concrete structures. This phenomenon is particularly of significance in structures the performance of which highly affected by the formation of wide cracks such as liquid containing structures. Most codes provide limited guidelines on amount of required reinforcement to control the crack width. The primary aim of this research is to study the minimum amount of reinforcement required to control the maximum crack width. The cracking behavior of reinforced walls subjected to volumetric deformations due to thermal and shrinkage strains is investigated using finite element method. A parametric study is performed to investigate the effects of wall geometry (length, height, length to height ratio, and thickness), concrete tensile strength, reinforcement ratio, and volumetric strain (climate) on crack width of reinforced concrete walls. For each of these effective parameters, the manner and the rate of impact on crack width are investigated. Based on valuable amount of data resulted from finite element analyses, a design recommendation is provided proposing a new procedure to determine the minimum reinforcement ratio needed to control shrinkage and temperature cracking in reinforced concrete walls.
Experimental Determination of Pull-out Strength of Threaded Steel Rods Mechanically Fastened into Glulam Beam Sections (ST71)
Cory Hubbard - Lakehead University, Sam Salem - Lakehead University
Threaded steel rods have been increasingly used as concealed connecting components in glued-laminated timber (glulam) frame connections. Embedding the rods in glulam beam ends has primarily been done with the use of adhesives. Connections for timber structures using concealed bonded-in steel rods offer a practical solution in the development of more efficient joining methods. However, the influence of adhesive type, specifically its properties and strength, are not yet fully understood and as such well-developed design criteria are lacking. For the research presented in this paper, instead of using adhesively-bonded rods, mechanically-fastened threaded steel rods were employed. The beam connection parameters investigated were rod embedment length and washer bearing area. A tensile force was applied to the steel rod, and linearly increased until the embedded connection failed. The strong steel rod in the connection resulted in the wood section failing every time, so a relationship between the embedment length and washer bearing area within the glulam section was observed. An understanding of this relationship would allow there to be a ductile failure mode of a weaker steel rod before any brittle failure occurred in the glulam section. Experimental results revealed that connections of 3/4-inch threaded steel rod mechanically fastened into black spruce glulam beam sections have pull-out strengths that range approximately between 66.2 kN for an embedment length of 150 mm and square washer size of 38.1 mm (1.5 inches), and 109.7 kN for an embedment length of 200 mm and square washer size of 50.8 mm (2.0 inches).
High strength reinforcement (HSR) - the smart solution for a sustainable future (MA55)
Florian Hude - MANA Ltd., Jaime Silva - SAS Stressteel, Inc.
In Canada and in Germany the recent limitation of yield stress for reinforcement bars is 500 N/mm². In the USA the code limit is 550 N/mm² and in some European countries reinforcement steel with higher yield strain (up to 600 N/mm²) is permitted. In the last decade more and more higher strength rebars were developed and the trends is towards this new reinforcement grade .
In general the advantages of HSR can be summarised with:
A smart construction solution does not only give the designer one advantage (higher strength) but allowes further enhancement: Changing the rib pattern in a way that the bar can be used as a threaded bar, there is no further manufacturing done to use the bar in a coupling system. This rebar-system allows further reduction of splice congestion, reduces development lengths and makes modular construction easy.
In several countries (USA, Germany, Poland, South Korea, ...) high strength thread bars up to 670 N/mm² yield strength are used already. This paper will lay out the properties of HSR, describes the code complience and will show several applications around the globe.
Numerical 3-D FEM of Finger-Joint Configuration for Spruce Wood Lumber (ST51)
Mohamed Essam Said - Memorial University of Newfoundland, Amgad Hussein - Memorial University of Newfoundland, Leonard Lye - Memorial University of Newfoundland
The objective of this study is to develop a 3-D finite element model of structural finger-joined spruce wood lumber. Finger joint (FJ) is the technique of joining the ends of two pieces of wood to make a longer piece. The numerical model is based on cohesive zone model using traction-separation law to model the interface between the two adherent parts. The properties of both the wood and glue need to be properly evaluated and implemented in the finite element model. The material properties comprised of 3-young’s moduli, 6-poisson’s ratios, and 3-shear moduli. The glue-line properties are the initial stiffness, damage initiation (described by the interface strength), and damage evolution (described by the interface fracture toughness) in a Mixed-Mode behaviour. The model was used to evaluate the structural performance of different FJ configurations. A total of six-specimens with dimensions of 38 mm × 89 mm × 1000 mm were tested in the laboratory to measure the deformation characteristics of the sample. Three of the specimens were reference samples while the other three had a FJ at the mid-span. The FJ length was 28.27 mm, the pitch was 6.33 mm, and finger-tip width (tip thickness) was 0.76 mm. FJs were assembled with a one face structural melamine-urea-formaldehyde adhesive of constitutive thickness 0.3 mm. The results showed that the load-displacement curves are in close agreement between the experimental and numerical model data which validated the developed model.
Keywords: 3-D Finite Element Model, Abaqus, Finger-joint, Cohesive Zone Models.
The durability and service life benefits of Stainless Steel Rebar and the underpinning properties and features – A stainless industry primer for owner’s, planners, specifiers, and designers on the technical and market realities (GC31)
Richard Huza - Salit Specialty Rebar
The tremendous cost of deteriorating infrastructure as caused by the corrosive effects of chlorides in North America is well documented as being in the billions of dollars annually. Owners, planners, specifiers, operators and designers of reinforced concrete structures faced with solving the problem of deteriorating concrete caused by chloride attack of the steel rebar from chlorides are looking for long term, low cost solutions and to solve the heavy cost burden of premature replacement of structures, excessive repair and maintenance costs, traffic congestion and reduced utilization. This paper makes the case that the fundamental and unique properties and features of stainless steel reinforcement are the underpinnings of the vast body of indisputable evidence pointing to stainless steel reinforcement as being a significant positive contributor to extending the service life of existing structures and enhancing the durability of new structures exposed to chloride attack. The author offers his engineering and product/market development perspective as a stainless steel reinforcement industry insider providing details regarding the unique mechanical properties, the chemistry of this product and the benefits which can be leveraged, an overview of the important aspects of the ASTM standard for mill production, the evolvement of historic to the current types of stainless steel reinforcement most in use, a summary of various corrosion resistance test methods and research presenting the relative performance of various types of corrosion resistant reinforcement compared to stainless steel reinforcement, the cost effectiveness of the use of stainless steel reinforcement as represented by a life cycle costing analysis with commentary on pricing, the specification formats and best practices of primary users, a perspective on the applications of this product and the primary users in North America, a synopsis of the mill material supply situation, and finally an overview of the purpose and summary of the recently released ANSI / CRSI IPG4.1 document “Standard Practice for Stainless Steel Reinforcing Bar Fabrication Facilities”.
Evaluation of Flexural Behaviour of Low-Density Fibre Reinforced Concrete Using Digital Image Correlation (MA23)
John Ibeawuchi - University of New Brunswick
Evaluation of Flexural Behaviour of Low-Density Fibre Reinforced Concrete Using Digital Image Correlation
John C. Ibeawuchi, Edward G. Moffatt, Alan Lloyd
University of New Brunswick, Fredericton, New Brunswick, Canada
Concrete is the world’s most widely used construction material owing to its excellent versatility, durability and economy. Despite all advantages associated with the use of plain concrete in civil engineering infrastructure, its use is sometimes limited because of its brittle nature and low tensile performance. To overcome these drawbacks, many researchers have adopted fiber reinforcement and it has become widely used to enhance the post-cracking tensile behavior of concrete. Despite these studies, there is still a setback in its application relating to design. One of these issues is the need to fully understand the flexural behavior of Fiber Reinforced Concrete (FRC). Many researchers have studied the effects of test method, fiber geometry, aspect ratio, type and volume fraction of the material in the mix on the post-cracking strength of FRC. Others have attempted to model the pull-out behavior of fibers in order to predict the flexural response of FRC. This paper presents the results of an experimental program to investigate the mechanical properties and post-cracking behavior of FRC beams under four-point loading using Digital Image Correlation (DIC). Expanded Polystyrene (EPS) light weight fiber reinforced (LWFRC) beams with two fiber types (steel and polypropylene) and different fiber volume contents (0%, 0.5%, 1.0%, and 1.5%) for each fiber type were cast and tested in flexure in accordance with ASTM C1609. This experimental work using Digital Image Correlation (DIC) gives details and detects the initiation and propagation of cracks on the specimens. It shows the failure mechanism, neutral axis shift and compression strain field of each mixture. These details were obtained with two digital recording cameras pointed towards the specimens as the bending test was ongoing and were analyzed using vic-3D image analysis software. Stress-strain curves obtained from the experiment were used to aid analysis and understanding of the behavior of the LWFRC. Results from the experiments showed that steel fiber had negligible effects on the compressive strength. Flexural strength and post-peak ductility were significantly improved with increase in fiber content of the matrix for both fiber types. However, the polypropylene fibers showed a significant drop in peak load after first crack.
Submitted for the 6th International Materials Specialty Conference at CSCE in Spring 2018 in Fredericton, NB, Canada.
Major Civil Engineering Projects Boost Local Workforce Competencies (EN15)
Diane Ingraham - Stantec Consulting Ltd, Wayne Tucker - Stantec Consulting Ltd., Willie McNeil - Stantec Consulting Ltd.
Major civil engineering projects provide opportunities to develop new competencies through strategic government policies and corporate mindfulness. The experiences gained on two such recent projects in Atlantic Canada are examined. The projects are: the “Tar Ponds Project”, a major environmental remediation and cleanup of the Sydney Tar Ponds and Coke Ovens site after 100 years of steel-making in Sydney, Nova Scotia, and the “Muskrat Falls Regulatory Compliance Project” for the 824 MW Hydroelectric Development on the Lower Churchill River in Labrador. Both multi-year heavy civil engineering projects shared challenges of large footprint on the land, multiple regulators and government levels, and very engaged stakeholders, including Aboriginal communities. This paper compares these projects to extract and consolidate practical project management insights gained to meet benefits agreement requirements through incorporating and coordinating local community workforces with specialist consulting engineers and scientists. These practical lessons learned inform civil engineering managers responsible for managing similar heavy civil and environmental engineering projects.
Societal Realities of Earthquakes and Prospects of Low- Damage Structures (DM8)
Asif Iqbal - University of Northern British Columbia
Building and infrastructure have been traditionally designed to ensure life safety and to protect people from serious injuries. Minor to moderate damage to the structures after a major event such as an earthquake is expected as an acceptable compromise. But a new level of realization has evolved in recent years in the wake of a number of earthquakes; the economic consequences of even a moderate event can be very severe even without any loss of life and catastrophic collapse of structures. The money and time required to repair damaged structures is unacceptable in many cases, particularly when the facility is out of service for a long period of time. There is increasing demand on the engineering community to find better solutions that avoid this type of scenario. The “Low-damage” concept has been proposed by researchers in New Zealand to eliminate the cause of such problems through solutions that provide building design concepts that result in minimum damage, can be repaired easily and quickly, and without significant cost. The realities and prospects are investigated for societies in developed and developing environments to awareness and avoid potential similar scenarios.
To understand the potential consequence of a major event, experiences are drawn from lessons learnt after a number of recent earthquakes. Figures of damages to buildings, lifelines and infrastructure will be gathered to quantify the short and long-term economic losses. The social effects of loss of lives, houses and livelihood will be evaluated in addition. The understanding of the realities faced by those societies in the wake of such disasters is used to develop potential scenarios in local contexts. The need and prospects of alternate engineering solutions are tested against predicted consequences of such scenarios. The results are useful in planning and policy decisions.
Impact of wind speed averaging time on the trend detection of historical extreme wind speeds in a changing climate (ST5)
Sihan Li - Rowan Williams Davies and Irwin Inc., Peter Irwin - RWDI
A previous study by the authors indicates that historical wind speeds may exhibit a statistically significant trend attributable to a changing climate. While data quality control was scrutinized, uncertainties from several causes were identified. These include changes of observation averaging time, data standardization for terrain effects and long term macro-climate variation. Each of these factors deserves investigation. As a following up study, this paper focuses on the first factor. The wind speed archived by Environmental and Climate Change Canada is reported as a “nominal” hourly mean wind speed at each hour. This nominal hourly mean wind speed is not an average over an entire hour. The most widely used dataset, HLY01, began by recording the one minute mean wind speed prior to the top of each hour, but changed to recording the two-minute mean wind speed before the top of each hour in 1985. This would indicate that the wind speed data prior to 1985 could be biased compared to those after 1985. This paper studies several stations in Ontario to investigate the impact of the change of averaging time on the detection of the trend in historical extreme wind speeds. The ratio of one-minute wind speed to two-minute average wind speed is treated as a random variable and Monte Carlo simulation is employed to randomly correct the one-minute wind speed to a two-minute mean wind speed before extracting the annual maximum wind speed. Trend analysis is then applied to detect the probable trend for the corrected extreme wind speeds. The impact of the change of averaging time on detected trends is discussed.
Estimating Under Ice Volume of Alberta Lakes using Minimal Data (GC39)
Zahidul Islam - Alberta Environment and Parks, Michael Seneka - Alberta Environment and Parks, Ernst Kerkhoven - Alberta Energy Regulator, Lauren Makowecki - Alberta Environment and Parks
Alberta’s lakes support important environmental, social and economic values. The effect of cumulative allocations over time from lakes within a watershed may impact the health of the aquatic environment, which include fish and wildlife resources. Therefore, water withdrawals from lakes should be regulated in such a way so that ecosystems are preserved while balancing reliable, quality water supplies to sustain communities and economic and recreational opportunities. To support provincial policy development, quantifying the potential impacts of water withdrawal from lakes, lake volume estimation using generally available data was tested. Accurate estimation of water availability in a lake requires a complete water balance study, which requires bathymetric information of the lake. However, only a fraction of Alberta lakes have surveyed bathymetry data. In this study, we analysed available bathymetry data from 77 lakes and developed a methodology to estimate lake volume from lake surface area. Information on lake surface area is easily available through satellite image/Google Earth and the method can then be used to estimate lake water availability. The methodology was also applied to estimate 5% Under Ice Volume (UIV5) of lakes for testing a proposed winter season allocation limit. It was found that for a specific ice thickness, UIV5 can be estimated only using the surface area of a lake with a satisfactory correlation coefficient (R2~0.9). This method can be used in absence of site specific data (e.g., bathymetry, lake mean depth) to estimate volume, and subsequently water availabilities in lakes and wetlands.
Computer software for the design of blast resistant window retention anchors (DM18)
Eric Jacques - Virginia Polytechnic Institute and State University, Murat Saatcioglu - University of Ottawa
Broken glass fragments and flying shards are a significant source of secondary injuries caused by window failure during accidental explosions and terrorist attacks. A comprehensive review of available design procedures used in the construction industry for window retention anchors, as well as related design standards, indicated that most of the previous research and development concentrated on the protective glazing of windows, rather than the anchorage of windows to substrates. This paper introduces BRADS (Blast Resistant Window Anchor Design Software), a computer program for the analysis and design of anchoring systems used in blast-resistant window glazing. The software is intended to aid engineers, architects, and manufacturers enhance the resilience of critical infrastructure against explosive events. The tool may be used to design new glazing anchorages or assess the vulnerability of existing anchors. The innovative design algorithm incorporated in the software can compute the required configuration of window retention anchors based on the major parameters known to influence anchorage capacity, including: substrate deformability, glazing response, window aspect ratio, frame rigidity, the distribution of dynamic reactions, combined stresses, and anchorage boundary conditions. The algorithm, developed and validated by the authors, satisfies the requirements of the new national standard on blast-resistant window retention anchors, CSA S852. The results generated by BRADS were compared against experimental data obtained from shock wave testing of blast-resistant window systems using the University of Ottawa Shock Tube and the University of Kentucky Blast Simulator. The comparison indicated that BRADS can predict the magnitude and distribution of anchor forces of the tested windows with a level of accuracy suitable for the purposes of design and assessment.
Resilience, Sustainability and the Infrastructure Bottom Line - Making and Defending Choices (GC63)
Martin Janowitz - Stantec
Resilience has become the central theme in much of the thinking, planning and response to all manner of unforeseen or catastrophic events disrupting or damaging our communities, particularly in this epoch of climate change disorder. But it is a term that suffers from simplistic or inconsistent understanding – from ‘bounce back’ or rebound-recover, to adaption or transformation; and approaches ranging from engineering to social-ecological orientations. Things get even murkier when we add ‘Sustainability’ into the mix. Resilience and Sustainability have a lot to do with each other but are not the same – resilience an attribute of dynamic, adaptive systems, and sustainability about the continued assurance of human and natural well-being. This paper proposes that the resilience we are trying to plan and design for actually helps us move towards desired future sustainable systems states, and not, by lack of forethought, undesirable ones. Linked with care, they become lynchpins in understanding and executing the sustainable infrastructure business case supported and enhanced by the use of Envision™. Envision has become the premier tool supporting the planning, design and evaluation of infrastructure seeking to optimize its alignment with the holistic and triple bottom line characteristics of sustainability. Envision™ recognizes that no project can ‘do it all’. In this dramatic era of climate change and infrastructure deterioration, this has never been more apparent or important to address. As we consider options for sustainability, resiliency and adaptation we must balance what is possible and what is feasible. Envision was developed to provide designers, owners and stakeholders with a transparent tool to understand, compare, evaluate and balance options. After 5 years’ experience, the newly released Draft Envision 3.0 enhances our ability to closely consider, make and defend these challenging choices. In particular, the inclusion of a new triple bottom benefit-cost assessment. This paper offers a bridge between these propositions - a progressive approach to resilience and sustainability and the need to make and defend difficult choices.
Problem or purpose: Clarifying the murky relationship between resilience and sustainability towards a coherent understanding and approach; and in that context, the benficial application of Envison as a methodology and tool to support decision-making.
Intended audience: Engineers, planners and designers, and owners, municipal officials and stakeholders play critical roles in our sustainability future.
A Week to Work it Out (GC157)
Christine Jeans - Stantec Consulting Ltd.
Consultation processes typically take time. Series of meetings spread over a year or more are normal. While it is important to take the time to consider issues and determine solutions, we have questioned whether extended lulls between consultation events are truly effective. The time citizens have to devote to a plan review or similar community issue is limited. As time passes many forget earlier discussions and lose focus on the point of the process.
In response, Stantec has recently developed and applied a “Consultation Program in a Week” approach that we have found effective not only to save time and costs, but also to enhance the quality of engagement. We concentrate consultation in a single week, in which our planners meet with community members, staff, and council. We normally meet twice with the public and close by meeting with the local council. Over a condensed timeframe we complete critical components of our research, our consultation responsibilities, and the components of our project deliverables.
We have used the approach successfully for plan reviews in the Towns of Montague, PE, and St. Alban’s NL, and the Community of Brudenell, PE. Most recently, we applied a similar methodology for our work on the Feasibility Study to assess municipal reorganization options for Wabush and Labrador City, NL. For each project, Stantec created a blog site to describe the project and announce consultation events. For the plan reviews, Stantec used the first meeting to establish issues and reported them online overnight. The following evening, we proposed potential solutions and reviewed them with interested citizens. Following the second meeting, we reported outcomes online and then met with the local council to discuss suggested responses to public input. We then prepared and presented a report to council summarizing recommended municipal plan and bylaw amendments. Formal plan preparation takes place separately with the benefit of well-documented public input. The completed planning documents are then presented to the public through additional consultation where it is deemed necessary and as required by applicable legislation.
This approach blends traditional engagement with current innovative communication tools, including blogging and online surveys, as well as social media platforms, such as Facebook, Instagram and Twitter. We will discuss how the process is immediate and open, saving on costs but more importantly, how it increases public comprehension, while providing rapid delivery of our products to our clients.
Best Practices Impacting the Cost Performance of Heavy Industrial Projects (GC85)
Mihai Robu - University of Calgary, Farnaz Sadeghpour - University of Calgary, George Jergeas - University of Calgary
The heavy industrial sector is a significant contributor to Canada’s economy. However, cost overruns are often experienced during the project delivery of heavy industrial facilities which impacts the organization and industry. Project management literature suggests that the implementation of management practices is one of the factors that can positively influence project success. As different management practices may have an impact on different phases of a project, this study will consider individual phase cost performance (front-end planning, detailed engineering, procurement, construction, commissioning) as opposed to overall project cost performance. The objective of this study is to identify which practices are associated with each phase’s cost performance. Project data on 1,015 heavy industrial projects from Canada and the United States will be analyzed. Descriptive statistics will be used to show the cost characteristics of each phase. Inferential statistics such as t-tests, Pearson’s correlation, and their non-parametric equivalents will be used to determine relationships between practices and phase cost performance. Knowledge of which phase a practice can impact aids practitioners in selecting the appropriate practices. The results of the study also highlight that management practices are not associated with better cost performance in every phase. Therefore, management practices may be combined in such a way that all phases can benefit from increased performance.
Process Options for Sewage Lagoon in Sub Arctic Canada (GC120)
Kenneth Johnson - Stantec / Cryofront
The existing sewage lagoon for the community of Fort Resolution, Northwest Territories is located in a waste management area approximately 1.5 kilometres north of the community centre . The current sewage lagoon was first commissioned in approximately 1979. The existing sewage lagoon on the site is a facultative/infiltration process consisting of seven cells ad hoc linked by channels. The treatment system begins at a truck discharge point into cell, and wastewater ultimately percolates through the sandy soil in a northerly direction to a wetland area in the Slave Lake delta approximately 400 metres from site. Detention in the lagoon and the infiltration process through the sandy soil provides treatment an equivalent secondary treatment of the wastewater.In 2008, it was anticipated that the sewage lagoon was approaching the end of its service life with its current configuration, as indicated by decreasing available freeboard in the cells. A Waste Management Planning Study was completed , which recommended the construction of a new lagoon to meet the twenty-year wastewater generation demand. The report presented 2 options: a facultative infiltration process, and a retention process. It was recommended that a facultative / infiltration lagoon be advanced, but it was recognized that this option may not receive regulatory approval. Based upon the ongoing concerns with the performance and operation of a facultative infiltration lagoon system, and regulatory feedback, a decision was made to advance the design of a lined two cell retention lagoon. Preliminary engineering was advanced on the new lagoon system in 2017, and a comparison of various configurations of a retention lagoon were considered. These configurations included a single lined cell, two lined cells with primary and secondary cells, and three lined cells with a polishing filter. The three cell configuration was a recent process innovation proposed as a result of a comprehensive research program on northern lagoon systems.Based on cost and the anticipated performance information on the lagoon systems, the two-cell lagoon process configuration proposed was confirmed to be the most appropriate option for Fort Resolution. The capacity of the proposed sewage lagoon is 32,000 m3 based on the sewage generation projection. The detailed design of the two cell process configuration will be completed in 2017, and the construction will proceed in 2018.
Assessment, options, and execution of remedial work for leaking sewage lagoon in Kugluktuk, Nunavut (GC121)
Kenneth Johnson - Stantec / Cryofront
The sewage lagoon serving the Hamlet of Kugluktuk is an earth berm structure, with a rectangular shape, supporting a single HDPE lined cell. The facility was commissioned in 2009, however, when the Hamlet began using the lagoon, it was identified that there were some tears in the lagoon liner, and remedial work to repair the liner was completed in 2011. Another issue with the lagoon liner, which was first observed 2009, are “islands” associated with floating segments of the liner. In 2014, it was reported that there was seepage from a segment of the toe on the east side of lagoon; it was also reported that there was subsidence in the top of the berm in the same section as the seepage.
A site inspection and review of the existing structure in July 2015 confirmed that a segment of the east berm had subsided approximately 40 centimetres. Associated with this subsidence was slumping and seepage in the same section of the east berm; additional slumping is also occurring in segments of the west and south berms.
Options were developed for remedial work on the lagoon, which included the addition of a buttress to the existing berm, berm reconstruction, removal and replacement of the existing liner, and repair of the existing liner. The capital costs for these options ranged from $400,000 to $4.6 million. For purposes of comparison, an option for the application of a mechanical treatment plant was also developed, and would cost $18 million. The buttress addition would not provide complete containment of the sewage, and therefore could require a relaxation of the operating criteria of the facility.
It was recommended that the remedial work be completed to provide a facility that fully contains the sewage, however it is recognized that the possibility exists for a relaxation of the operating criteria. This relaxation would could allow the leaking to continue, and accommodate the addition of a buttress structure to the existing berm to provide long term stability to the structure. The design of a buttress structure was completed, and the remedial work was undertaken in 2016. Ongoing monitoring of the remedial work and the overall lagoon is continuing to determine if the buttress is an appropriate long term solution.
Influence of the relationship with the boss on the relationships with others in project-based industries (GC144)
M. Hossein K. Jamali - ASU, Avi Wiezel - ASU
The results of this research will allow employees working in project-based industries (such as construction, software, or R&D) to better understand the balance between tasks and relationships. This, in turn, will provide a more productive and intellectually rewarding work environment while reducing turnover. The research also hypothesizes that there will be a difference between the influence of the bosses among the three typed of organizations studied: (a) hierarchical organization (1 boss), (b) matrix organization (2 bosses), and (c) 3D matrix organization (3 bosses). Initial results confirm this hypothesis and illustrate the specific differences. The results may be used to decide the most suitable organization structure for project-based divisions. Literature shows that the relationship between boss and employee is eventually influenced by the individual's performance. The research question addressed in this dissertation is: how much does one's relationship with the boss influence the relationship with peers, subordinates and other people that contribute to the success of the individual. In other words, the question is "how important is to the team one's relationship with the boss?". The current literature seems to be focusing exclusively on the boss and neglects looking at the other contributors to the success of the individual. In this research, those other contributors are referred to as stakeholders". The literature also fails to address the question if the quality of the relationships is intrinsic, or it is led by the boss. This research utilizes a unique data collection method called “Who’s On Your Molecule”(WOYM). The WOYM is a leadership instrument where participants are required to list their stakeholders and score the quality of their relationship with them in an all-day workshop at Construction Industry Institute (CII). Instead of relying on declared data obtained through surveys and interviews, WOYM collects revealed data, data collected while placing the participants in specific situations and observing their responses.
Dynamic Deterioration Modeling to Predict the Future Sewer Conduits Conditions (GC3)
Khalid Kaddoura - AECOM, Tarek Zayed - The Hong Kong Polytechnic University
With no doubts, sewer networks serve an essential element of any infrastructure system. Its main duty is to transfer sewer medium from any inlet to treatment plants or disposal areas. Therefore, it ensures healthier environment to any community. Sewer pipelines are buried in nature; as a result, their conditions are rarely triggered unless collapse situations occur. Nevertheless, some efforts have been accomplished in designing specific inspection cameras and sensors to help assessing sewer pipelines considering several sewer protocols. These protocols supply condition grades that suggest the overall conditions of the assets. Therefore, decision-makers can monitor the pipelines’ states throughout their service lives. However, these conclusions encourage reactive maintenance, which results in significant costs and time when compared to proactive strategies. One method that could promote deploying the latter strategy is the deterioration modeling. These models are specially designed to predict the future conditions of any asset. Therefore, it assists practitioners in scheduling for inspection and deciding on the maintenance, rehabilitation or replacement (MRR) actions. As a result, the objective of this research is to design a dynamic deterioration model by employing the Weibull distribution analysis. The methodology shall propose three different deterioration curves: i) the ideal deterioration curve, which describes the ideal states of the pipelines’ deterioration considering a specific service life; ii) the updated deterioration curve (UDC), which models the deterioration of the pipeline considering the condition after inspection; iii) the predicted deterioration curve (PDC), which models the deterioration of the pipeline after rehabilitation actions. This study is expected to provide informative conclusions for decision-makers when it comes to planning for inspection or MRR decisions for sewer pipelines.
Exploring Challenges Associated with Large Scale Air Transportation Infrastructure Planning and Execution (TR48)
Sharareh Kermanshachi - University of Texas at Arlington, Shirin Kamalirad - University of Texas at Arlington, Thahomina Jahan Nipa - University of Texas at Arlington
Several U.S. airports are currently engaged in large-scale, multi-year capital improvement programs. For many airport counsels, these programs are once-in-a career occurrences. Although these programs present many of the same issues as smaller scale airport construction projects, these large programs also present a series of specialized environmental, financial, and legal issues. Therefore, the aim of this study is to provide an overview of the challenges presented by large-scale airport construction programs and various strategies to address these problems. To fulfill the objectives of this study, three in-depth structured interviews with Subject Matter Experts (SMEs) from both academia and industry were conducted and analyzed. In these interviews, detailed qualitative data regarding several aspects of airport development and construction challenges, and also their potential overcoming strategies were collected. This study provided detailed analysis of airport construction difficulties regarding following challenges: environmental permitting issues for large capital improvement programs, increasing legal difficulties due to multiple source of funding challenges, addressing local issues through public outreach and education, transitioning tenants and operations from existing to new facilities, phasing and staging of construction process, and using incentives (both liquidated damages and bonuses) to accelerate the progress of airport construction projects. This study also collected and analyzed several case studies regarding each of the described airport transportation development challenges. The outcome of this study helps policy makers to plan construction of large-scale air transportation modes appropriately and allocate the required funding accurately.
Feasibility Analysis of Post Disaster Reconstruction Alternatives Using Automated BIM-Based Construction Cost Estimation Tool (DM26)
Sharareh Kermanshachi - University of Texas at Arlington, Behzad Rouhanizadeh - University of Texas at Arlington
Reconstruction of damaged or totally devastated constructions is an immediate action needed after occurrence of a disaster. Among various reconstruction alternatives, the one which is technically and economically justifiable is what the decision-makers inquire. To determine the economic viability of an alternative, the accuracy and quickness of the used techniques are very decisive. Since in a post-disaster situation acting quickly is the priority, the traditional manual cost estimation methods are not feasible. Based on the previous studies, there is a need for a tool to quickly and automatically calculate the construction cost of the proposed alternatives. This paper proposes an automatic cost estimation methodology and develops a Building Information Modeling (BIM) based decision-making tool to automatically obtain the construction cost of the different construction alternatives for post-disaster reconstruction. To develop this Application Programming Interface (API), C Sharp (C#) programming language was used and then it was added to Revit environment. In addition, the code was programmed to extract the needed data from RSMeans database. The difference between this code and other existing ones could be due to the high level cost estimations as it uses the quantity of elements rather than computing based on materials and/or detailed design. This tool can be used for decision-making for large number of projects within a very short time. This tool saves time required for evaluation of the feasibility and practicability of different construction options and is a useful decision support tool for decision-makers. Furthermore, by means of this tool, human-based errors will highly reduce and a more efficient and accurate cost estimation will be performed. By modeling the project geometry, the above-mentioned tool determines the number of each element, selects the unit cost for each element, computes the total cost for each element and calculates the final construction cost of the whole project. To verify the developed tool, a residential building case study was selected, and the cost of various design alternatives were estimated. To visually illustrate the application of the developed tool, this process is graphically explained and presented in detail. The main application of this BIM-based tool is when an area is drastically touched by a severe disaster and the constructed facilities are entirely demolished. Under this circumstance, quick rehabilitation of the affected areas is the priority action of corresponding decision makers. Therefore, implementing this prompt tool could assist policy-makers and authorities with immediate decisions and the tool acts as a
Strengthening Slender Circular Concrete Columns with a Novel Hybrid FRP System (ST13)
Koosha Khorramian - Dalhousie University, Pedram Sadeghian - Dalhousie University
In this paper, the performance of steel reinforced slender concrete columns strengthened with longitudinal bonded carbon fiber-reinforced polymer (CFRP) composite laminates is investigated. All concrete columns were reinforced using six longitudinal steel rebar (15M) and transverse circular steel ties (10M). A total of ten large-scale specimens with circular cross-section with a diameter of 10 in were prepared and tested under eccentric compressive loading up to failure. To limit the unsupported length for the longitudinal CFRP laminates and avoid early buckling of the strips, transverse glass FRP (GFRP) wraps were applied to the surface of the strengthened columns. Two different reinforcement ratios for longitudinal CFRP laminates were used as well as two different eccentricities. Moreover, different slenderness ratios of 17, 22, 40, and 60 were considered. Strain of CFRP laminates were monitored during the tests to evaluate the usable level of strain and mode of failure of strips. This is an in-progress research and results will be provided in the full paper.
New Testing Method of GFRP Bars in Compression (MA7)
Koosha Khorramian - Dalhousie University, Pedram Sadeghian - Dalhousie University
Although glass fiber-reinforced polymer (GFRP) bars have been recognized as an alternative for steel bars in concrete structures and there are standard methods for test them in tension, there is no standardized and convenient test method to figure out their compressive characteristics. Therefore, this study introduces a new test method for testing GFRP bars in compression. This test method focuses on providing a circumstance under which the evaluation of compressive crushing strength and modulus of elasticity of GFRP bars would be possible without experiencing buckling of bars. Two steel caps are attached to the end of each specimen to avoid premature failure as well as adjusting the alignment of the coupons. Also, two strain gauges were installed on each specimen to capture the strains at the mid-height of the GFRP specimens. Using the proposed test method, a total of fifteen GFRP bar coupons from two different manufacturers were prepared and tested under concentric pure compressive loading. The coupons were divided into three groups including five identical specimens in each group. Different bar dimensions and material properties were considered. The results were consistent in terms of modulus of elasticity and mode of failure.
Fires Being the Cause of Collapse of Steel Frame Office Buildings (ST92)
Robert Korol - McMaster University
The purpose of our submission is to investigate the extent to which present-day design of steel framed buildings are susceptible to total collapse when subjected to extreme fire events. We select a 50 storey structure in which 2 and 4 adjacent storeys located at different above-ground heights are, in separate scenarios, engulfed in raging fires. A total of 8 scenarios are analyzed, employing Newtonian mechanics and realistic energy dissipating properties of H-shaped columns and normal concrete floor slabs possessing secondary (shrinkage and temperature) reinforcement alone. The present Canadian building code is the basis for our column designs under loading conditions for which gravity loads control. Other attributes whcih would in practice participate in absorbing the kinetic energy of a crush-down upper block are excluded. Desite such conservative assumptions, it is shown that while partial collapse might indeed occur, there is no scenario that predicts a total collapse. These results should provide some comfort to code writers that present requirements should indeed prevent the most catastrophic of failures due to fires, and might indeed suggest to fleeing occupants alternative routes to safety instead of the desperation cases of window jumpers noted during the WTC fire events 16+ years ago.
Failure analysis of transmission line steel lattice towers subjected to extreme loading (ST56)
Kahina Sad Saoud - Université de Sherbrooke, Sébastien Langlois - Université de Sherbrooke, Alex Loignon - Université de Sherbrooke, Charles-Philippe Lamarche - Université de Sherbrooke
Lattice towers are extensively used in overhead transmission lines, owing primarily to their lightness and cost-effectiveness. The modeling of such structures is usually laborious due to various complex factors including connection eccentricities, rotational stiffness of connections, bolt slippage, among others. Therefore, full-scale tests are usually performed for the qualification of new overhead line supports, which is a time-consuming and expensive process. Numerical models used in practice rely on simplified hypotheses, using linear truss/beam elements assumed to be pin-connected at both ends. Such models are combined with standard design equations to only evaluate the members’ axial capacities. Finite element models involving solid/shell elements are generally more accurate, though, the computational cost of the resulting problems makes it very difficult to evaluate the response of a complete tower. This paper presents an advanced numerical approach using beam elements aimed at predicting the load-bearing resistance of steel lattice towers under static load cases. Such approach will serve not only to verify the design of new towers, but also to understand various phenomena leading to the collapse of towers in the case of premature failures. The proposed model is developed using the finite element package Code_Aster, wherein lattice towers are modeled using spatial beams. The highly nonlinear problem is solved in an incremental way using advanced features to deal with both geometric and material nonlinearities. An example of a lattice tower loaded until failure is presented and compared with analogous experimental test. The effect of different geometric imperfections on the failure is particularly highlighted.
Resistance and Failure Modes of Cold-Formed Lipped Angle Subjected to Tensile Load (GC48)
Therese Tajeuna - Université de Sherbrooke, Sébastien Langlois - Université de Sherbrooke
Cold-formed steel angles could be an advantageous alterative to hot rolled steel angle for the application of light-weight electrical transmission towers. However, standard design equations to evaluate the resistance and failure modes in tension of angles connected with bolts on one leg only were not specifically developed and validated for the application of lipped angles. In particular, the phenomenon of shear lag on this type of angle is difficult to evaluate. In this paper, the behavior of cold-formed steel lipped-angle with typical transmission tower bolted connections is studied. At first, experimental tests on two and three bolts connections are performed. Tensile load is applied on a single angle configuration to investigate the failures mode and capacity of the connected members. Then, three dimension (3D) finite element (EF) models of the bolted members are developed. The accuracy of the FE models is validated by the good agreement with experimental study. Results obtained from these investigations added to other published results are compared to recommended design prediction with the aim to assess their validity and limitation. From this, a new design equation for net-section strength is proposed.
Demanding Change / Changing Demand (TR19)
Adam Lanigan - Dillon Consulting
It has become increasingly clear in recent years that traditional methods of forecasting and analyzing future demands for transportation infrastructure are largely out of step with the progression of many provincial and municipal agencies towards a more equitable, sustainable, and integrated transportation network that seeks to curb auto use and increase the use of transit and active modes. Estimating ‘demand’ to solely be the number of cars on the road and equating success with pushing more cars down that same road is a surefire way to maintain the car as the dominant – and in some cases, only – choice for moving around. As the goals of the transportation system evolve to meet changes in policy, so too must our methods of forecasting and analyzing the demand for this system.
This presentation examines the changes that will be required to reposition transportation demand forecasts to serve the desired outcomes within the framework of new data sources, new transportation technologies and services, and an increasingly knowledgeable, nimble, and flexible travelling public. Important in all of this will be the evolution of practical and cost-effective solutions that are not restricted to academic research, but can be applied on real-world projects to help municipalities and provinces to achieve their policy goals. The presentation is broken into five main focus areas to allow for discussion of the various issues, as below:
Investigation of the changing need and availability of travel data in light of the advent of GPS and the smartphone.
Traditional modelling processes treat complex daily journeys as a series of disconnected events, but in reality each trip is linked and relates directly to the choices made along the way.
As the principles of sustainable transportation and integrated mobility have come to the fore, it is increasingly important to understand more about the people making the trip.
Trends related to how people get around need more consideration in light of changing priorities, technologies, and disruptors like automated vehicles, on-demand ride and bike sharing, and technologies not yet considered.
The measures we apply in our analyses should be directly linked to the policy goals to allow for the city to evolve appropriately and cost-effectively.
A Newer Time-frequency Decomposition-based Modal Identification Technique for Structures (ST98)
Ayan Sadhu - Lakehead University, Sandeep Sony - Lakehead University, Malek Lazhari - Lakehead University
In last few decades, structural health monitoring has gained significant popularity to perform condition assessment of civil structures. A wide range of system identification methods have been developed by different researchers to accurately identify modal parameters from the measured vibration data. One of the popular time-frequency methods, namely empirical mode decomposition (EMD), has been very popular owing to its basis-free nature and applicability to any nonlinear and nonstationary signals. However, the EMD results in significant mode-mixing in the modal responses. In this paper, two different classes of newer EMD methods are proposed to undertake ambient modal identification using just single channel measurement. The proposed method is fully adaptive and suitable for automation since it uses only one channel of data at a time. The proposed method is verified using a suite of numerical and experimental studies.
Developing Three Dimensional Hydrodynamic Model for Lake St. Clair (EN42)
Mohammad Madani - University of Windsor, Rajesh Seth - University of Windsor, Luis Leon - ECCC, Water Science and Technology
Lake St. Clair is part of the connecting channel between Lake Huron and Lake Erie. This channel serves as a recreational waterway, source of drinking water for Detroit and surrounding cities, as well as a shipping channel to Lakes Huron, Michigan, and Superior. There are several public beaches on Lake St. Clair and the microbial water quality at these beaches is constantly changing. Current one and two dimensional steady state hydrodynamic models developed by Environment and Climate Change Canada (ECCC) are able to provide depth averaged general water circulation patterns in the Lake. In order to better track the sources of microbial contamination or to develop the capability of predicting the level of microbial contamination at the beaches in real time, it is expected that a model with capability to predict the unsteady hydrodynamics in 3D space and time will be necessary.
In the current study, a 3D unsteady numerical model of Lake St. Clair was set up over a four-month period (June-September) of 2010 using the ELCOM hydrodynamic modelling framework and validated against observations. The bathymetry file used was obtained from NOAA/Great Lakes Environmental Research Laboratory data and the depths are referenced to a generic datum of 176.784 meters (580 feet). Flow and Temperature data of the four major rivers loads to the lake (Thames, Sydenham, St. Clair river, and Clinton Rivers) and the only outflow (Detroit River) were also obtained using the nearest station’s information. Necessary interpolation was done for missing data. Meteorological forcing data sets consisting of wind direction, wind speed, air temperature, humidity atmospheric pressure, short and long-wave radiation, and rainfall were obtained from the nearest stations and moored surface buoys. Data were QA/QC checked by Environment and Climate Change Canada (ECCC) and the NOAA National Data Buoy Center.
Model output was used for better understanding the circulation and temperature profile in Lake St. Clair. The vertical distribution of temperature revealed little to no stratification in the water column, which is expected in a shallow lake such as Lake St. Clair. Modelled temperature was compared with buoy recorded water temperature. Both the model predicted profile and the temperature values were in good agreement with the observed data with root mean square error (RMSE) and mean absolute error (MAE) values of 1.1 ºC and 0.9 ºC respectively.
Measurement of near-bed turbulent flow over roughness elements in an open channel (GC96)
Jing Li - Concordia University, S. Samuel Li - Concordia University
Roughness elements at the channel-bed and their influences on near-bed flow have attracted a great deal of research attention over a long period of time, because of their significant impacts on the flow behaviours and implications for environmental applications. Previous studies created bed roughness using different kinds of materials, including rectangular ribs and irregular gravel. Roughness elements in the form of square-shaped cubes are arguably more realistic, but laboratory experiments for detailed velocity measurements over cubes are rare. We performed experiments of flow over acrylic cubes, and investigated their effects on near-bed flow characteristics. These experiments used a flume of 700 cm long, 33.5 cm wide, and 60 cm high, with glass sidewalls and a smooth metallic bed. During the experiments, the depth of flow ranged from 8.8 to 9.1 cm. The discharge was maintained at around 14.6 L/s (or 52.5 m3/h). Cubes of 1.905 cm (or 0.75 inch) in length, width and height, were uniformly mounted at the horizontal bed. The experiments covered three cases of different cube crest-to-crest spacing: 3.81, 7.62 and 11.43 cm (or 2, 4, and 6 times the cube dimension), which, respectively, represent d-type, intermedium type, and k-type roughness. An acoustic Doppler velocimeter (ADV) was used to measure 3-D velocity at an array of locations above and around the cubes. The ADV sampling volume was 0.25 cm3. The sampling frequency was set to 120 Hz. At each location, the measurements lasted 60 s. The ADV was installed on a rail-mounted platform. Its positioning in the along-channel, cross-channel and vertical directions was controlled by a step motor, which could allow a moving distance of as small as 1 mm. In the horizontal, the measuring section was from the upstream edge of the cube of interest to the downstream edge of the next downstream cube. In the vertical, the measurements nearest to the bed were 2 mm above it. We present experimental results of flow structures. Contour plots of the longitudinal velocity component showed that the flow was not perfectly symmetrical about the cube’s longitudinal centerline. The results show distinct vertical profiles of mean flow velocities and turbulence parameters under the three spacing conditions. We also present distributed shear stresses from analyses of the ADV output using four different methods. This work contributes to an improved understanding of rough-bed hydraulics. The detailed velocity data are useful for computer model validations.
Investigation of open-channel flow under a sluice gate (GC12)
Bowen Xu - Concordia University, S. Samuel Li - Concordia University
Investigation of open-channel flow under a sluice gate
Bowen Xu and S. Samuel Li
Department of Building, Civil and Environmental Engineering
Montreal, QC H3G 1M8
Sluice gates are useful for the control of discharge and flow depth in open channel systems. Previous studies of the problem of flow a short distance upstream and downstream of a sluice gate have led to the successful development of some convenient empirical equations of integral form. The focus of this paper is on the internal distributions of the velocity field and pressure field. In this paper, the Reynolds-averaged Navier-Stokes equations are numerically solved for velocity and pressure, the k-e model is used for turbulence closure, and the volume of fluid method is used to track the free water surface. This paper includes laboratory flume experiments of flow under a sluice gate, which produced measurements of free surface positions, and pressure distributions. Experiments were carried out for a series of ratios of the upstream flow depth (y1) to the gate opening (b). These experiments allow a direct comparison between the measurements and numerical predictions. The comparison confirms the quality of the numerical results, and the suitability of the modelling methodology. The contraction coefficient (Cc) or the ratio of the flow depth (y2) at the vena contracta to the gate opening asymptotically approaches 0.635 as the y1/b ratio exceeds a threshold value of seven. Below this threshold value, Cc falls in the range of 0.64–0.69. The experimental and modelling values of Cc from this study are larger than the value of 0.61 reported in the literature. The difference is possibly due to the growth of the bottom boundary layer downstream of the sluice gate, as predicted by the laboratory-scale numerical model. The scale effects are investigated by implementing the numerical model at the field scale, producing computational results complimentary to experimental data.
Theoretical study of hydraulic jumps in steep storm sewers (GC101)
Chunli Wang - Concordia University, S. Samuel Li - Concordia University
In the design of storm sewers, pipes are often laid on slopes dictated by the actual slope of the terrain, and the slopes can be very large in some urban drainage systems of mountainous areas. The flow in a steep sewer pipe can be easily disturbed, causing an abrupt change from supercritical to subcritical state through a hydraulic jump. Downstream of the hydraulic jump, the flow can come into contact with the pipe vertex, and thus flow choking occurs. This paper focuses on a theoretical analysis of the above-mentioned flow phenomenon involved two connected sewer pipes laid on different slopes. For given values of pipe diameter, discharge, and slope, pertinent variables of flows in the pipes are determined by using the Manning’s formula and the momentum equation. Values of the Froude number, Fr, in response to an increase in the slope of the upstream pipe and/or in discharge from upstream, are calculated. The occurrences of hydraulic jumps as well as their downstream sequent depths are predicted. The maximum filling ratios of upstream flow for which choking occurs at a series of slopes are determined. This paper contributes to practical solutions to the increasingly common problem of waterlogging in urban centres.
In-plane behaviour of masonry infilled RC frames subjected to quasi-static cyclic loading (ST165)
Yi Liu - Dalhousie University
Effects of Low Temperature and High Strain Rate on the Compressive Behaviour of Concrete (MA50)
Thomas MacLean - University of New Brunswick, Alan Lloyd - University of New Brunswick
Concrete is a material that has been used in structures for centuries, yet there is still uncertainty concerning its material properties in certain situations. Explosions and large impacts are dangerous to structures due to their high force and impulsive nature. When combined with the effects of extreme temperature, a structure can be pushed to its limits, which could result in a catastrophic failure. The research presented here is a preliminary investigation into this largely unexplored design scenario, focusing primarily on the effects of low exposure temperature and high strain rates on concrete materials. The primary purpose of the research was to experimentally determine design factors that incorporate these combined effects on the compressive behaviour of concrete. The experimental program consisted of testing 101.6 mm x 203.2 mm (4” x 8”) concrete cylinders in uniaxial compression under static and dynamic strain rates. Static loads were applied by a compression machine and dynamic loads were applied by a drop mass impactor at the University of New Brunswick. The specimens were exposed to four different temperatures from +20 °C to -70 °C by means of placing them in a regulated freezer or a dry ice environmental chamber to cool. The concrete cylinders had two thermocouples embedded near mid height with one located at half of the radius and one at the center. These thermocouples were used to determine a thermal gradient in the specimens during tests. The strain response of the specimens during testing was determined by using Digital Image Correlation (DIC). DIC is a non-contact optical technique that can be used to monitor strain and displacement by comparing digital photographs taken throughout the duration of the test. A high-speed camera was used for dynamic tests with a frame rate of 20000 fps. Stress – strain curves were generated for all static and dynamic samples, allowing for direct comparisons of peak stress and strain between the test conditions. Design equations and relationships between the dynamic increase factor (DIF), temperature increase factor (TIF) and combined increase factor (CIF) are presented. The research is significant as temperature and strain rate dependent material properties are very important to consider in engineering designs for dynamically loaded structures exposed to the extreme temperature variations observed annually in Canada or storage facilities where liquid natural gas and other industrial materials are contained.
The use of digital image correlation to demonstrate tension member behaviour in structural steel design (ST121)
Nathan McNeil - University of New Brunswick, Alan Lloyd - University of New Brunswick
The design of tension members in steel structures can be a difficult concept for students to learn. For bolted tension members, an analogy can be made to the capacity being the weakest link in a chain. Tension member design needs to incorporate a wide variety of different ultimate limit states including yielding, fracture in tension, shear and tension block failure, inclined tension failure in the case of staggered bolts, shear lag, bolt bearing, and bolt shear. The different nature and high number of failure modes make learning tension member design difficult for new students. A testing program was conducted at the University of New Brunswick to explore different tension member failure mechanisms with the goal of developing qualitative and quantitative content to incorporate into teaching of undergraduate civil engineering students. Digital image correlation (DIC) was used to monitor the tests and compute shear and tension strain fields that provide visual and numerical validation of design concepts.
Three bolted tension member specimens are presented in this paper: a flat bar, an angle, and a channel. All specimens were tested using a universal testing machine. The flat bar was a hot rolled FB6.1X152 designed with a staggered bolt pattern. The bar failed along the staggered bolt pattern in an inclined tension mode. The digital image correlation gave provided visualization of the inclined tension plains leading to failure. The L102X102X9.5 angle was designed with two rows of transverse bolts. It failed in a tension and shear block mode. The effects of shear lag, bolt bearing, and the tension and shear plains were clearly shown by the strain field visualizations from the DIC. The channel, a C150X12, had three rows of transverse bolts and was designed to fail in a tension and shear block mode. The DIC visualization of strain shows both the tension and shear plains leading to failure as well as the shear lag that was present in the channel flanges.
Digital image correlation has many applications in non-contact measurements of deformations for research purposes, however, the main motivation of this project was to use this technology to create visualizations that will help students learning structural steel design. These visualizations of the shear and tension strains are being incorporated into the classroom setting. With help from the digital image correlation, a connection between design equations, theoretical material mechanics, and the behavior of steel in a real-world application can be made.
Planning the Keswick Substation Transformer Move (GC117)
Peter Lougheed - exp Services
On Sunday, October 22nd, 2017, a 255 tonnes transformer arrived at the Keswick NB Power Substation. The route taken by this oversized load began in the Netherlands several weeks earlier, and the overall plan to move the load, including evaluating various routes and travel modes, began more than three years before it departed for New Brunswick.
Five potential routes were originally considered, with the positive and negative aspects, including feasibility and risks, identified for each option. One of these options, which was not chosen due to risks and other conditions, was to load the transformer onto a barge at the Saint John Harbour and barge the load all of the way up the Saint John River to Fredericton. At that point, the transformer would be unloaded from the barge onto the 20-axle carrier and moved by highway to the substation. Other route options involved traveling on roadways within the city of Fredericton and barging over the Mactaquac head pond.
The ultimately chosen travel route from the Netherlands to Keswick included barging from the point of manufacture to the European port of departure, traveling by cargo ship across the Atlantic Ocean, and traveling by train from Halifax Harbour to the Napadogan CN railway siding. Once the transformer arrived at this siding, it was loaded onto a 20-axle articulating trailer that was pushed and pulled by several full-sized trucks. The load traveled along provincial and forest roads, including passing over many structures that were identified as not having the structural capacity to facilitate such a load. This structural inadequacy was overcome when the option to use temporary bridge ramps, which could span the problematic structures and place minimal loads on their components, was implemented, allowing the ultimate route to be finalized.
In the end, it took four days to move the convoy through the 75-km route, on both provincial highways and forest roads, including properly setting up and removing the temporary bridge ramps as well as several detours. The move went well, with no major complications, and the transformer arrived safely at the substation.
Full-Scale Monitoring of a Tall Building Equipped with an Efficient Tuned Sloshing Damper System (ST69)
Shayne Love - RWDI Inc., Bujar Morava - RWDI Inc.
Modern high rise construction materials and techniques have led to the proliferation of tall buildings that are lightweight, flexible, and possess low inherent structural damping. As a result, they are often susceptible to excessive wind-induced dynamic motion, which may cause discomfort for occupants on the upper storeys. Tuned Sloshing Dampers (TSDs) can be employed as an affordable, efficient, and simple means to reduce wind-induced motions to acceptable levels for occupant comfort. A TSD consists of a tank located near the top of the structure, which is partially filled with water. As the building sways under wind action, the water within the tank will slosh. When properly designed, the force imparted to the structure by the sloshing water will counteract the wind loading, significantly reducing the building motion.
In traditional multi-tank TSD installations, all tanks are tuned to the natural frequency of the structural mode being targeted by selecting the tank length, width, and water depth. When the TSD design is conducted this way, the TSD system can be represented as a single, large tank. However, more recent research has shown that improved performance of the TSD system is achieved if the tanks are set to slightly different frequencies near the structural mode being controlled, instead of having all tanks identically designed.
This study first overviews a simple model describing the response of multiple tuned sloshing dampers (MTSDs) with frequencies distributed near the structural frequency. Using this model, the advantages of this MTSD system are illustrated. The performance of the MTSD system is verified using long-term full-scale measurements of a high rise building located in Toronto. To the authors' knowledge, this is the first building in the world equipped with this type of efficient MTSD
Preliminary Numerical Modelling of a Tuned Liquid Damper with Limited Freeboard (ST79)
Kevin McNamara - Department of Civil Engineering, McMaster University, Michael Tait - Department of Civil Engineering, McMaster University, Shayne Love - RWDI Inc.
A tuned liquid damper (TLD) is often used to mitigate the wind-induced vibrations of tall slender structures. A TLD typically consists of a partially filled rigid water tank located near the top of a structure and is often equipped with screens or devices to increase energy dissipation. The required freeboard for the TLD tank is determined by calculating the maximum sloshing wave height and ensuring sufficient space such that the water does not impact the roof of the tank. A TLD tank designed such that the water can impact the roof would reduce the space required in the structure. To implement a TLD with limited freeboard for a structure, it is necessary to understand the effect that limiting the freeboard has on numerical modelling, TLD performance, and structural tank design. This paper discusses preliminary research on numerical modelling of a TLD with limited freeboard and sloshing water impact with the tank roof. A smoothed particle hydrodynamics (SPH) model is implemented to study a TLD equipped with slat screens for both unlimited and limited freeboard. A comparison between the results of each case is presented. The limited freeboard case is observed to potentially reduce the higher sloshing modes in the tank. Significant spikes in pressure on the tank boundaries are observed for the limited freeboard case. A comparison to existing numerical models shows differences in the magnitude of sloshing response. Refining the treatment of the slat screens in the SPH model may provide improved agreement with existing models.
Adapting Pavement Infrastructure to flood risk under climate change --A Review of Adaptation Strategies (DM7)
Donghui Lu - CPATT - University of Waterloo, Susan Tighe - CPATT - University of Waterloo, Wei-Chau Xie - University of Waterloo
Flooding is one of the most common natural hazards in Canada. Climate change is expected to increase flood risks caused by frequent and intense precipitation, and sea level rise. The implications of climate change influence the construction, design, planning, and management of pavement infrastructure as a result of flooding. In order to live better with the consequence of global warming, appropriate actions should be taken to prevent or minimize pavement damage, and ensure a satisfied pavement performance. Climate change adaptation help reduce the pavement vulnerability to extreme weather events, and thus offset the effects of global warming. This paper reviews adaptation strategies for managing pavement flooding risk from various aspects. Research literature, current inventories, policies, and adaptation framework and plans from Canada and other developed nations are reviewed. A framework and guideline for implementing adaptation strategies are established for researchers, pavement managers, and other stakeholders to make better adaptation decisions and increase pavement system resiliency.
Design and formulation of concrete with Polyethylene Terephthalate (PET) using statistical mixture design (MA2)
Natalia Vivas - Memorial University of Newfoundland, Leonard Lye - Memorial University of Newfoundland, Baiyu (Helen) Zhang - Memorial University
This paper investigated the incorporation of waste Polyethylene Terephthalate (PET) from plastic bottles into concrete as a replacement for natural fine aggregate and found an optimal combination of components that produces a useful concrete product. Six components were considered: cement, water, coarse aggregate, fine aggregate, superplasticizer, and waste PET. A total of 31 mixes were prepared based on a statistical mixture design approach. The responses of these mixtures were workability, compressive strength, and splitting tensile strength. The waste PET was first reduced in volume by shredding and then combined with the rest of the components. The responses from the experiments were statistically analysed and a model fitted to each response. Linear models were found to fit the responses best. Using the desirability function approach, four optimal options were selected and then verified in the lab by comparing the experimental with the predicted values. Except for one, all the values fell within the 95% prediction interval. The average response values obtained with the optimal combination were: (1) compressive strength of 23.8 MPa; (2) slump 123 mm, and (3) splitting tensile strength of 3.33 MPa. This mix can be used in basements foundation walls or slabs, inside buildings not exposed to freezing temperatures. It is recommended that future work should consider method of mixing, time of mixing, volume of mix, curing conditions, and other responses to further understand the characteristics of incorporating waste PET into concrete.
Keywords: Polyethylene Terephthalate (PET), concrete aggregate, statistical mixture design.
Failure Mode Analysis of Buckling-Restrained Braces with FRP Shells (ST43)
Daina MacEachern - Dalhousie University, Pedram Sadeghian - Dalhousie University
In this paper, the failure mode of a new buckling-restrained brace (BRB) system with fibre-reinforced polymer (FRP) composite shell filled with self-consolidating grout is analyzes. The objective of this research is to determine the behaviour and structural capabilities of the FRP-BRB system as well as its feasibility to real-life applications. An analytical model is developed to predict the governing failure mode of the system, whether it be overall buckling or yielding of the steel core. Different parameter is considered, including slenderness ratio of steel, diameter of FRP shell, strength and modulus of FRP, and strength of grout. The parametric study will result in optimum diameter and thickness for FRP shell and grout strength. The solution can be applied in the field allowing for the existing bracing to remain while increasing its buckling capacity and ductility. The results will also establish a platform to develop design procedures applicable for rehabilitation of existing steel structures. The research is currently in-progress and results will be included in the final paper.
Recycled Ground Oyster Shell for Use as Filler in Self-Consolidated Grout (MA13)
Daina MacEachern - Dalhousie University, Pedram Sadeghian - Dalhousie University
In this paper, the mechanical properties of self consolidating grout with various levels of replacement of sand with ground oyster shell is investigated. The objective of this research is to determine the behaviour and structural capabilities of the alternate filler and determine its feasibility as an environmentally friendly and cost saving solution. In this research, various levels of replacement of sand, namely 5, 10, 15, 20, 30 and 35% are investigated to find an optimal level. A base line grout without oyster shells was designed as a bench mark for strength and slump flow. All mixes were designed to have a similar slump flow as the bench mark by varying water content. Mixes consist of water, type N cement, mortar sand, superplasticizer, and ground oyster shells. Six grout cubes were prepared for each mix and were tested in compression at 7 and 28 days. Oyster shells were prepared by washing and drying followed by being passed through a jaw crusher twice and 4 minutes in a pulveriser. This is research in-progress and results will be included in the final paper.
Effective Use of Recycled Asphalt Shingles for Granular Materials (MA45)
Matthew MacEachern - The University of New Brunswick, Xiomara Sanchez - University of New Brunswick, Won Taek Oh - University of New Brunswick
The province of Prince Edward Island (PEI) imports 20,000 to 100,000 tons of aggregates per year for construction purposes. It is estimated that close to 8000 tons of tear-off shingles (end of life roofing shingles) are sent to local landfills annually. To reduce aggregate import costs and to utilize Recycled Asphalt Shingles (RAS), the University of New Brunswick (UNB) has been working closely with the province to investigate the use of RAS as a partial replacement of high quality quarried aggregates (Granular Class A) for its potential use as a granular base in pavements.
The main objective of the present study is to suggest an optimum combination of RAS and Granular Class A. The individual gradation curves for each material were obtained and the theoretical design indicated that a replacement of up to 30% of RAS by weight could meet provincial specifications. Three suitable combinations of RAS/Granular Class A were selected (10/90, 20/80, and 30/70) for testing and quantifying the impact of RAS in the mechanical properties of the material. Proctor tests were conducted to determine the Optimum Moisture Content (OMC) for each combination. Based on the standard proctor test results, California Bearing Ratio (CBR) tests were then carried out for the mixtures compacted at OMC. The resilient modulus for each combination were then estimated using empirical relationships with the CBRs found in the literature.
It is expected that with the successful use of RAS in granular materials, a significant amount of shingles can be kept from entering local landfills and up to 30% of import costs can be reduced.
Predictive modelling of recreational water quality at two beaches in Windsor Essex Region, Ontario, Canada (EN45)
Mohammad Madani - University of Windsor, Rajesh Seth - University of Windsor
Swimming in contaminated waters may result in gastrointestinal and respiratory diseases. To protect bathers from swimming in such polluted waters, microbial water quality is typically monitored for fecal indicator bacteria (FIB), such as Escherichia coli. Although E. coli is considered as the most suitable indicator for recreational water monitoring according to Guidelines for Canadian Recreational Water Quality, its measurement takes 18 to 24 h before results are available. However, water quality of nearshore region can change over a matter of hours. Thus unsafe microbial water quality for recreational water use cannot presently be identified in a timely manner. Statistical models based on commonly measured weather data and easily measurable water quality that can predict E. coli concentration can be a possible solution, provided such a model can be developed and is shown to be accurate.
Daily E. coli concentrations and select water quality parameters were monitored during 30 consecutive days of Summer 2010 at Sandpoint beach (Lake St. Clair) and Holiday beach (Lake Erie) in Windsor Essex Region in a previous study. Weather data were obtained from the nearest Environment Canada station for each beach. The present study examined the collected water quality and weather data and their various transformations to develop a multiple linear regression model using the United States Environmental Protection Agency (USEPA) Virtual Beach (VB) toolbox. Variables considered included rainfall, wind direction, wind speed, turbidity, conductivity, air and water temperature, dissolved oxygen, pH and conductivity. E. coli were log10 transformed before use in the development of the linear regression model.
Results show although turbidity was the most important variable in VB model for both beaches, different combinations of other variables were found to be significant for each of the two beaches. While polynomial transformed turbidity, 24h rainfall and wind direction along shoreline were significant parameters in Sandpoint beach VB Model, LOG(turbidity), wind direction and INVERSE(wind_direction) were the most important variables for Holiday beach. Good correlation between the fitted VB models and observations were observed for both beaches. For the Sandpoint beach VB Model, the R2 value was observed to be 0.78, root mean square error (RMSE) of 0.27 logCFU/100mL, sensitivity of 0.75, specificity of 1.0 and accuracy of 96%. Holiday beach VB model had RMSE of 0.26 logCFU/100mL and higher R2 of 0.89. Sensitivity, specificity and accuracy of model for Holiday beach are observed to be 1.0, 0.96 and 96% respectively.
Effect of Rainy Darkness Intensity at Two-Lane Highway on Travel Time Differentials (TR3)
Opeyemi Makinde - University of KwaZulu-Natal, Opeyemi Makinde - University of KwaZulu-Natal
In this paper travel time differentials prompted by rainy darkness on Two-Lane Highway were investigated. The investigation raises the issue of night travel on roads without lights. Even though drivers react to rainfall and darkness simultaneously, studies have not been carried out insufficiently. Hence the paper wants to provoke debate on this issue. Based on the hypothesis that rainy darkness irrespective of intensity will cause travel time increase, with and without rainy darkness studies were carried out at four sites selected sites in Nigeria during rainy season (June-August). Traffic and rainfall data were collected continuously for eight weeks. Rainfall intensity was classified according to the conventional rate of precipitation: Light rain — when the precipitation rate is < 2.5 mm (0.098 in) per hour. Moderate rain — when the precipitation rate is between 2.5 mm (0.098 in) - 7.6 mm (0.30 in) or 10 mm (0.39 in) per hour. Collated data on which the study was based were analyzed. Travel times for with and without rainy darkness were estimated and compared. Results show that there is speed reduction of 5% due to light rain effect, 12% and 21% due to moderate and heavy rain effect respectively. Further, travel time increase relative to speed decrease during rainy darkness, thus suggesting that motorists reduce vehicle speed when it is dark and rainy irrespective of intensity. The paper concluded that rainy darkness has significant effect on travel time.
Incorporating Fast-track Pavement Repair Methods into Current Infrastructure Management Practices (TR12)
Dahlia Malek - University of Waterloo, Victoria Speller - University of Waterloo, Susan Tighe - CPATT - University of Waterloo
Pavement infrastructure deteriorates due to environmental conditions, traffic loading, and material aging. Regular maintenance and repair is required to maintain an acceptable level of service. High-traffic volumes and heavy traffic can increase the rate of pavement deterioration, necessitating more frequent rehabilitation or maintenance on these roadways. However, construction is often limited to a short window to minimize user impacts. Another common problem in asphalt roadways is pavement cracking; it is important to repair cracking to prevent further deterioration of the roadway. Accelerated construction or “fast-track” methods provide a solution to repair and extend the service life of pavement infrastructure, quickly, easily, and with minimal construction-related delays.
Throughout this paper, two examples of fast track pavement repair methods are discussed and compared to traditional repair methods. Precast concrete inlay panels are used to rapidly rehabilitate structural rutting on high traffic volume highways, and infrared heating technology is used to quickly repair cracking of asphalt pavement. The objective of this paper is to examine the innovation, benefits, and drawbacks of these fast-track pavement rehabilitation methods and to present their role in pavement management. This paper investigates the project-level decision-making process of selecting between these new fast-track repair techniques and the existing traditional repair methods by examining various decision criteria.
Methodology for Performance Evaluation of Precast Concrete Inlay Panels as a Pavement Repair Technique (TR13)
Dahlia Malek - University of Waterloo, Daniel Pickel - University of Waterloo, Susan Tighe - CPATT - University of Waterloo
Deep-seated rutting of asphalt pavements has been observed on some high-traffic volume highways in Ontario, Canada. The current rehabilitation technique of milling and replacing the asphalt has been observed to last for only 3 to 5 years. The use of Precast Concrete Inlay Panels (PCIP) is a new rehabilitation strategy that provides a longer service life and can be installed rapidly during overnight lane closures to minimize construction-related impacts on roadway users. A trial construction of PCIP was completed in 2016 on Highway 400 near the city of Toronto. Evaluating the long-term performance of PCIP is necessary to ensure that this rehabilitation strategy is feasible and provides the expected level of service. The objective of this paper is to establish a methodology to assess the performance of the PCIP based on monitoring, testing, and inspections of the trial site and by modelling PCIP using ABAQUS finite element analysis (FEA). The trial site will be inspected for panel and joint condition and distresses. Instrumentation installed on site is used to collect data remotely. Deflection testing, roadway surface friction testing, profile measurements, and noise testing will also be completed. The performance of PCIP will be evaluated for various traffic, temperature, site and construction conditions using FEA. Deflection results can be used to calculate theoretical joint faulting and load transfer efficiency of the joints. Stresses and strains in the concrete and dowel grout will be used to predict whether concrete/dowel grout crushing or tensile cracking will occur.
Modeling of Concrete Bridge Decks Deterioration using a Hybrid Stochastic Model (GC99)
Eslam Mohammed Abdelkader - Concordia university, Mohamed Marzouk - Cairo University, Tarek Zayed - The Hong Kong Polytechnic University
Infrastructure systems represent a very important aspect of life on Earth. Existing Infrastructure is subjected to degradation while the demands are growing for a better infrastructure system in response to the high standards of safety, health, population growth, and environmental protection. Bridges play a crucial role in the urban development by providing access for people to services such as health care units, schools, markets, etc. Bridges are vulnerable to high levels of deterioration because of some factors such as deferred maintenance actions, extreme weather conditions, variable traffic loading, etc. A reliable deterioration model is required for the successful development of Bridge Management Systems (BMSs) which helps in performing accurate maintenance, repair, and rehabilitation activities. This paper presents a hybrid Bayesian model that is capable of predicting the condition ratings of the concrete bridge decks along its service life. Bayesian belief networks (BNs) are utilized to model the factors that affect the condition rating of the bridge decks. BNs are used to calculate the transition probabilities based on the severity of five bridge defects which are: corrosion, delamination, cracking, spalling and pop-out. Finally, a Markovian model is used to predict the future performance of the concrete bridge decks. A case study of the concrete bridges in Quebec is presented to demonstrate the capabilities of the proposed model.
Implications of Climate Change to Coastal Cities and the Need for Engineers (EN2)
Edward McBean - University of Guelph
Issues influencing the sustainability of coastal cities are characterized, reflecting the combination of impending sea level rise and storm surges, and increasing growth in the world’s populations in coastal cities. Geologic-time scales are utilized to draw parallels to characterize relevant historical occurrences that help to understand the context of projections of impending sea level rise issue to year 2100. Given that Antarctica holds sufficient water to raise global sea levels by 58 m if the ice were to melt, this indicates that even a small percentage of melting of the polar ice caps, should this occur, will have enormous implications to the sustainability of coastal cities which are projected to hold 12.4 percent of the world’s population by 2060. The result is the combination of predicted sea level rise and associated storm surges indicate that drastic measures need to be promoted to improve the sustainability of coastal cities. The need for engineers, and engineering innovation, is going to greatly increase as the world attempts to address the challenges of sea level rise and storm surges. The specific example of Biloxi, Mississippi during Hurricane Katrina will be used to demonstrate the magnitude of impending coastal issues and engineering needs.
Fiberglass Sandwich Beams with 3D Woven Fabric Cores (ST25)
Aidan McCracken - Dalhousie University, Pedram Sadeghian - Dalhousie University
Composite sandwich beams composed of fiber-reinforced polymer (FRP) skins and low-density core materials have been shown to be effective in reducing weight and increasing structural efficiency in a variety of applications. The FRP skins resist the tensile and compressive stresses as a result of bending, while the core resists shear stresses, provides insulation and increases the distance between skins resulting in an increased moment of inertia. In this study, sandwich beams made of glass FRP (GFRP) skins and a 3D woven fabric is used for core are tested and analyzed. Specifically, either zero, one or two layers of fiberglass fabric were used for the skins and a 3D fabric, with a nominal thickness of 8 mm was used for the core. A total of 29 small-scale sandwich beam specimens were manufactured across six unique beam varieties with dimensions of 50 mm in width, 25 mm in depth, and 200 and 350 mm in length (150 mm and 300 mm spans) to be tested under four-point bending up to failure. The load-deflection behavior of the test specimens was analyzed. Additionally, the flexural and shear stiffness of the sandwich specimens were calculated. Overall, the 3D fabric core displayed promising structural behavior. However, it will be shown that as a result of the higher strength/stiffness skins, the sandwich beams with two layers of GFRP skin displayed weaker structural performance caused by a premature failure due to longitudinal shear stress. Thus, it may be concluded that compatibility between the skin and core is a key factor in optimizing composite sandwich beam performance.
Case Study: History and Refurbishment of 145-Year-Old Rail Bridge Piers, Southwest Miramichi River Bridge in Miramichi, NB (GC174)
Benjamin McGuigan - GEMTEC
The CN Rail Bridge over the Southwest Miramichi River in Miramichi, NB was built between 1870 and 1874 as part of the Intercolonial Railway system, with Sir Sanford Fleming overseeing the design and construction as Chief Engineer. Over the last 100 years various repairs and upgrades have been made to the bridge and its substructure. In 2017 CN Rail began a rehabilitation program to address deterioration of the masonry piers and local scour around the piers. This case study outlines pertinent details of the original construction, summarizes various repair works that have been undertaken over the years, and outlines the approach taken with the recent rehabilitation work.
A Methodology for Feasibility Analysis of Demand-Responsive Transit Services (TR7)
Yongzhe Yang - University of Regina, Babak Mehran - University of Regina
Low ridership is a significant challenge for bus transit services in small to medium municipalities in Canada, especially for newly developed areas, residential subdivisions, and communities with specific social-economic characteristics. Under low demand conditions, bus transit operators have to pay a high cost per passenger to maintain desired level of service. Therefore, Demand-Responsive Transportation (DRT) becomes an alternative option for transit agencies. Unlike regular transit services which run on fixed routes and schedules, DRT operates per user requests on variable routes or schedules to reduce operating costs while providing acceptable level of service. DRT service is preferred when demand for public transportation is low. However, as the demand or bus ridership increases, a regular bus service is more efficient. Determining the critical demand levels for switching from a regular bus service to DRT is essential for transit operators. A methodology is proposed to evaluate and compare the oprerational costs of offering regular and demand responsive bus services. The proposed cost model for regular bus service has three independent parametrs i.e. fleet size, vehicle service hours, and vehicle traveled distance. Model parameters were estimted using the City of Regina’s bus transit data. Two DRT service models were considered: 1) Contract-out Taxi Service (CTS) and, 2) In-house Paratransit Service (IPS). Additional operating cost models were develped for proposed DRT services using the data provided by the City of Regina and CTS service prviders. The proposed cost models can be used to estimate expected operational costs of regular and demand responsive bus services as function of demand. A low demand bus route in Regina was used as a case study to demonstrate the application of the proposed methodology. The relationships between operating costs and demand were evaluated using the developed models for regular bus and DRT services. The impacts of variations in ridership and oprating conditions on operational costs were evaluated and critical demand levels for offering each transit service type was determined. The proposed methoodology can be used by bus transit service providers as a decision support tool while establishing standard procedures to offer regular bus or DRT services.
Case Study: Anaerobic Membrane Bioreactor (AnMBR) Systems Treating High-Strength, High-Solids Food Processing Wastewater (GC179)
Zaiyan Mi - ADI Systems, Daniel Scott - ADI Systems
Anaerobic Membrane Bioreactor (AnMBR) Systems Treating High-Strength, High-Solids Food Processing Wastewater Dwain R. Wilson1, Shannon R. Grant1, Mike J. Allison1, and ZaiYan Mi1, 1ADI Systems, 370 Wilsey Road, Fredericton, New Brunswick, Canada E3B 6E9 INTRODUCTION Ken’s Foods manufacturing company has been making salad dressing, sauces, and marinades for over 60 years. Their production facilities include locations in Massachusetts and Georgia. Its high-strength industrial wastewater contains high chemical oxygen demand (COD), high biological oxygen demand (BOD), high total suspended solids (TSS), and fat, oil, and grease (FOG) concentrations. Original wastewater treatment at the Georgia location used a conventional approach including the removal of FOG and suspended solids via dissolved air flotation (DAF), followed by an activated sludge system and a centrifuge system for sludge dewatering. Considering the requirements of plant production expansion, land space limitation, and the desire for renewable energy utilization, cutting-edge anaerobic membrane bioreactor (AnMBR) technology was selected as a means to upgrade the original wastewater treatment system to handle the flow and load expansion. The first commercial full-scale AnMBR system in North America was installed at Ken’s Foods Marlborough plant in Massachusetts in July 2008, to treat high-strength industrial wastewater with high concentrations of organics, suspended solids, and FOG. Nearly ten years of successful continuous operation of the Marlborough AnMBR system gave Ken’s Foods confidence that this solution would also work at other locations. Therefore, Ken’s Foods once again selected ADI AnMBR technology for a second production plant located in McDonough, Georgia, USA. The McDonough plant AnMBR system was built in 2017, and is one of the world’s largest AnMBR installations in terms of design flow and organic load. ADI-AnMBR Technology The state-of-the-art AnMBR technology, successfully commercialized for full-scale applications in 2000, is the latest innovation in biological wastewater treatment. The AnMBR process incorporates anaerobic digestion and membrane filtration in one process that effectively treats high-strength wastewater within a compact footprint. The near-absolute (zero TSS) membrane barrier performs the gas-liquid-solids separation to ensure efficient system operation and stability and produces a superior effluent quality while maximizing the biogas production, which can be used as a renewable fuel source. KEN’S MARLBOROUGH PLANT The AnMBR system at Ken’s Foods Marlborough plant was commissioned in July 2008. The AnMBR system consists of an existing anaerobic reactor (ADI-BVF®) plus four membrane tanks, equipped with submerged membrane units. It was designed to treat 125,000 gpd of raw wastewater with 39,000 mg/l COD, 18,000
Effects of Sticky Rice on 56-day Compressive Strength of Cement Stucco containing Lime and Slag (MA57)
Zhe Zhang - Université de Moncton, Buquan Miao - Université de Moncton, Gérard Poitras - Université de Moncton, Yong Xun - Yancheng Institute of Technology
As the concept of green building becomes increasingly popular, it is meaningful to find a stucco with better mechanical property and less environmental effect. As a traditional organic admixture, sticky rice has been widely used in the construction of ancient architectures, and it has been proved that it can significantly improve the compressive strength of lime mortar. As an industrial waste, slag can chemically react with cement and lime, and its utilization can also reduce environmental pollution (Lei Hui, Francesc Lopez Almansa. 2017). By mixing the sticky rice slurry, lime, slag with Portland cement, this paper studied the compressive strength of stucco. Results show that when the dosage of sticky rice is 1%, the dosage of lime is 10% and slag content is 30%, the stucco has a relatively higher compressive strength after 56 days.
Keywords: Portland Cement, Lime, slag, Stucco, Sticky Rice, Compressive Strength
How to Teach an Old Dog New Tricks: Bonnie Doon Leisure Centre Rehabilitation Edmonton (ST58)
Monique Miller - Entuitive Corporation, Mohammad Moayyed - Entuitive Corporation
A small community focused aquatic facility, could have been levelled and built anew, but instead has undergone a transformation.
The term ‘rehabilitation’ does not accurately describe the level of rejuvenation undertaken to prolong and re-capitalize this facility. The project exemplifies many fundamental challenges of altering existing buildings. Not only did the building require restoration of key structural elements that suffered significant deteriorated due to 50 years of use; new programming and operational requirements resulted in significant changes to all systems (mechanical, water treatment, electrical and architectural and structural). Alterations include, but are not limited to:
Upgrade of mechanical ventilation systems requiring the addition of two very large AHU and HRV units.
Addition of building envelope system requiring assessment of concrete block integrity and structural capacity of exterior walls.
Upgrade to salt water treatment requiring perimeter pool gutter (significant, surge tank, salt storage, acid room, various mechanical and electrical upgrades).
The paper focuses on how to work within the design and project delivery confines of renovating an existing building including:
The Design Process: Discussion of the cyclical process of investigating structural options at an early stage using the example of locating the new mechanical ventilation units. Where should they be located, what size will they be, what current code requirements will affect their impact on the base building structure?
Structural Alterations: Requirements of salt water treatment system, the most significant being a continuous perimeter gutter that disconnects the one-way pool deck slab from the pool wall support. Challenges included designing a successful supplemental framing system to support the gutter and slab while weighing the impacts of schedule, design team requirements, constructability, and cost implications.
Restoration and The Importance of Structural Health Monitoring: Many primary structural elements at the facility sustained significant deterioration due to the breakdown of waterproofing systems, inherent flaws and lack of regular maintenance program. Could the deterioration have been prevented? What kinds of options exist to re-instate structural integrity?
The final result is a facility seemingly new, but in fact the outcome of a mindful, creative alteration of a community landmark.
Can’t Plug the Source? Plug the Flow (GC165)
Graham MacKenzie Walker - University of British Columbia, Ryan Mills - AECOM Canada Ltd, Joanna Runnells - Crown Contaminated Sites Program
The Case Study of the Atlin Ruffner Mine Remediation Water Management focuses on innovative application of automatic siphon technology to overcome cold weather and remote region engineering challenges.
The abandoned mine site was once used for the extraction and refinement of silver-lead ore. Several underground mine adits were advanced, and one borehole was purposefully drilled to provide a continuous supply of groundwater to the mill to meet processing needs. When the mine was abandoned, these groundwater flows continued do discharge to surface, presenting a risk to the physical and chemical stability of the site.
The objective of the project was to divert the groundwater discharge around the site to prevent the water from interacting with site contaminants including waste rock and tailings. The primary challenges that constrained the design and are examined through this case study include:
Several options were considered as part of an options evaluation, including source control and open channel conveyance but were determined unsuitable. The selected option involved design of a pipeline to divert flows around the site, but low winter flows and severe frost left the pipe subject to freezing. To resolve this issue, an automatic siphon was employed. These devices are typically used for residential septic field dosing. The technology was employed at Atlin Ruffner to provide plug flows (i.e., flow surges) with a sufficient volume and cycling interval to mitigate the risk of freezing. To provide redundancy, buried interceptor trenches were also constructed to intercept and divert groundwater flows around two tailings ponds. The interceptor trenches were designed with excess capacity to convey flows that would result from failure of the adit drainage pipeline.
AECOM Canada Ltd. would like to provide recognition to the Government of British Columbia, Ministry of Forests, Lands, Natural Resource Operations and Rural Development, Crown Opportunities and Restoration Branch to whom we acted as agent for this project.
Effect of Fire on MSE Highway Retaining Walls and Bridge Abutments (GC92)
Shahriar Mirmirani - Reinforced Earth Company Ltd., Ertiana Rrokaj - Reinforced Earth Company Ltd.
In recent years, Mechanically Stabilized Earth (MSE) walls have gained wide acceptance among North American and international transportation jurisdictions as a more versatile alternative to cast-in-place (CIP) retaining walls. While MSE structures are designed to fulfill a variety of retaining purposes, similarly to CIP walls, there exist fundamental differences with respect to their susceptibility to heat and fire. This paper will investigate how fire conditions can affect the performance of MSE structures for highway retaining walls and bridge abutments. The paper will (a) comment on relevant government regulations regarding the design of highway structures under fire conditions, (b) summarize and report on studies conducted on heat conductivity from fire on MSE walls, and (c) analyze the effect of fire on different types of soil reinforcements (plastic, metal) and precast concrete panels. Finally, this paper will identify the consequences from potential failure modes of MSE structures under fire conditions and discuss solutions for prevention including appropriate design considerations.
Effects of Freeze-Thaw Cycles and Deicer Salt Brine on the Tensile Strength of Recycled Asphalt Mixtures (MA42)
Shahab Moeini Feizabadi - University of New Brunswick, Xiomara Sanchez - University of New Brunswick, Bruce Wilson - University of New Brunswick
In places of the world with severe seasonal variations, such as the province of New Brunswick, asphalt concrete mixtures are subjected to cyclic freezing and thawing during the cold months. Moreover, different types of deicers are frequently used to mitigate the effects of snow, ice, and freezing rain on the pavements for increasing the levels of service of roadways. Despite having many safety advantages, the use of deicers has raised concerns over the effects on pavement materials. Salt is one of the most common deicer products in New Brunswick and understanding its effect on the durability of asphalt concrete would help pavement managers to improve the determination of maintenance, preservation, rehabilitation, and the estimation of the life-cycle costs of pavements assets. This study investigated the effects of Freeze-Thaw Cycles (FTCs) and Deicer Salt Brine (DSB) on the tensile strength of recycled asphalt mixtures and conventional Hot Mix Asphalt (HMA). In partnership with NBDTI (New Brunswick Department of Transportation and Infrastructure), ten different mix design of plant-produced asphalt mixtures, including recycled hot mixture and conventional HMA were collected from different parts of New Brunswick. These samples were subjected to different conditions simulating extreme weather in New Brunswick, including rain, freeze-thaw cycles, and the use of deicers over the pavement. For each source, Tensile Strength Ratio (TSR) was determined to estimate the stripping susceptibility of each source material. The results from each source were then compared to evaluate the general performance differences between recycled and conventional HMA in New Brunswick, and this characterization is applicable to the development of new cost-effective pavements in the province.
Design and Construction of a Snowmelt Management Facility in Southern Ontario (EN20)
Matthew Senior - Wood Environment & Infrastructure Solutions, Ron Scheckenberger - Amec Foster Wheeler, Ryan Moore - City of Hamilton
Winter conditions, including snow and ice, are a reality for Canadian drivers, including those in Southern Ontario. Local municipalities and other government agencies are typically charged with ensuring safe roadway conditions for motorists, including clearing and plowing snow. In areas with limited space within the roadway right-of-way, plowed snow may be transported off-site and disposed of with little or no environmental or runoff controls. Untreated snowmelt water has been demonstrated to be a significant environmental concern to downstream receiving watercourses, with elevated levels of suspended solids, chloride (salt), as well as numerous other water quality contaminants.
A recent example of the design, and ultimate construction of a snowmelt management facility in Hamilton, Ontario is presented. An integrated “treatment” train approach was employed for the design, which included the design of a large appropriately graded asphalt melting pad, an oil/grit separator for pre-treatment, and a specifically designed wet pond facility involving a retrofit of an existing stormwater management (SWM) facility for final treatment and dilution. The system was also designed to have a complete SWM function (quantity and quality control) under non-snowmelt (i.e. rainfall-driven) conditions.
Design considerations specific to the management of snowmelt contaminants (salt in particular) are discussed and presented. Perspectives of different stakeholders involved in the management of roadway snow are also considered, including municipalities (engineering and operations and maintenance groups), regulatory authorities, and designers.
Numerical Modelling of Slender Superelastic-shape Memory Alloy Reinforced Concrete Shear Walls (ST38)
Mena Morcos - York University, Dan Palermo - York University
A study is currently in progress to assess the self-centering capacity of Superelastic (SE)-Shape Memory Alloy (SMA) reinforced concrete slender shear walls. This study is based on numerical modeling to provide predictive assessments of the seismic behaviour and the ability to recover from imposed lateral displacements. Two ductile shear walls were constructed for future testing that will corroborate the nonlinear finite element analyses. The control wall was constructed with conventional deformed steel reinforcement in the longitudinal direction of the web and boundary zones, and in the transverse direction for shear reinforcement and buckling-prevention ties. A companion SE-SMA wall was constructed with similar reinforcing details, with the exception of replacing the conventional longitudinal steel reinforcement in the boundary zones with superelastic Nitinol SMA bars. The SMA bars were limited to the height of the plastic hinge region. Beyond the plastic hinge zone, the SMA bars were coupled to deformed steel reinforcement through mechanical couplers. The walls will be subjected to quasi-static load reversals, defined by a set of consecutive displacements, to failure. Axial loading is not imposed on the walls to reflect perimeter walls with low axial load. The focus of this paper is on preliminary nonlinear finite element analyses, which illustrates that the SMA reinforced wall provides approximately 61% displacement recovery; whereas the companion steel reinforced wall provides only 24% recovery after being subjected to 2.5% lateral drift. The damage predicted by the numerical model is substantially reduced in the SMA wall in comparison to the steel wall at similar levels of lateral displacement.
Impact of Aged Contamination on Bioventing Performance (EN4)
Richard Zytner - School of Engineering, University of Guelph, Mei Xiao - University of Guelph, Michael Mosco - Meritech
Bioventing can be an effective in situ remediation method to clean-up a site contaminated with petroleum hydrocarbons. The challenge in getting bioventing to work properly is determining the optimum conditions needed to stimulate the native microorganisms so that the bacteria degrade the petroleum hydrocarbons. Sufficient research has been done to identify the type and amount of nitrogen needed, and the optimum water content as a function of soil. Work has even been completed on estimating scale-up factors so that smaller laboratory experiments can be run, and then the degradation rate adjusted to represent what would take place at a larger scale. The one issue still needing investigation is the impact of aging. Aging happens when petroleum hydrocarbons are released into the soil and stay in contact with the soil for an extended period of time. This causes a bond to develop between the contaminant and the soil particles, making it difficult for the microorganisms to easily breakdown the petroleum hydrocarbons. As such, research was completed on aged soil to gain insight into the aging phenomenon.
Experiments were completed by spiking two types of soil to about 8000 mg/kg four to six months in advance and storing the mixture in a refrigerated sealed container. Some additional experiments were completed by spiking the soil and then conducting tests at regular intervals to determine when aging had an impact on degradation. The degradation experiments completed consisted of 150 g respirometer and 80 kg bioventing reactor. The respirometers showed an increase in degradation rate for the loamy sand, from 0.045 d-1 for freshly contaminated soil to 0.114 d-1 for soil aged up to 300 days. In contrast, review of the 80 kg reactor results showed that degradation rate of the aged experiments for the loamy sand soil was half that of the freshly contaminated reactor test; 0.053 d-1 as compared to 0.118 d-1. In both cases, a sharp reduction in extractable contaminants was observed due to an increase in aging. This reduction in bioavailability was further seen by the silt loam soil test where no degradation was measured after 250 days of aging. The tests and analysis showed that the petroleum contamination was so tightly bound that microorganisms could not access the petroleum hydrocarbon. These results show that aging impacts the bioavailability and the rates of biodegradation, ultimately increasing the time required to attain site closure in large-scale experiments.
Throughput Evaluation of Workzones on High-Volume Highways of Ontario, Canada (TR10)
Seyedata Nahidi - University of Waterloo, Sonia Rahman - Stantec, Susan Tighe - CPATT - University of Waterloo
Highways as the primary type of transportation infrastructure, allow for haulage of huge amounts of goods and services in North America. Several parameters such as high volume of heavy truck traffic and long winters in Canada could result in faster deterioration of the pavement infrastructure. To improve the safety and traffic planning of the highways geometry, and structural performance of the roads, transportation agencies should have a detailed program to maintain, preserve, and reconstruct these infrastructures.
Work zones interrupt the regular traffic flow on the highways which potentially increases the number of accidents. To prevent these safety issues, agencies are encouraged to present a comprehensive strategy to minimize the queuing in the work zones. The Ministry of Transportation Ontario identified that accurate prediction of work zone throughput could significantly reduce the user delay costs, and increase the safety of the high-volume highways.
This paper involves the evaluation of the work zones throughput performance. To that end, various strategies such as Multiple Linear Regression, Negative Binomial Regression, and Truncated regression models were developed to identify the parameters which are affecting the number of throughputs of the work zones. An innovative concept of random parameter method was also used to account for unobserved heterogeneity issue.
Results showed other than traditional factors, factors such as the number of closed lanes, the length of the work zone, the presence of police time of day, and percentage of heavy trucks have significantly affected the throughput of the work zones located on high-volume highways.
Strength Prediction of UHPFRC-filled Closure Strip between Precast Bridge Desk Slabs Incorporating Ribbed-surface GFRP Bars (ST16)
Ilion Ndreko - Ryerson University, Khaled Sennah - Ryerson University, Hosam Sennah - Ryerson University
In accelerated bridge construction, the use of glass fiber reinforced polymer (GFRP) bars as internal reinforcement in concrete is a viable option for the expedited replacement of deteriorated concrete bridge deck slabs, where corrosion of steel reinforcement is of main concern. This research seeks to determine the effect that concrete strength has at the joint and investigates the use of ribbed-surface GFRP bars in the closure strip between jointed precast deck slabs resting over the girders. The jointed deck slab utilizes two vertical shear keys, one on each side of the closure strip. GFRP bars in the precast slabs are proposed to project with straight ends into the closure strip, which is then filled with ultra-high performance fibre-reinforced concrete (UHPFRC). In this research, the behavior of GFRP reinforcement in UHPFRC is studied using full-scale tests of different lap splices at the closure strip in 200x600x2800 mm one way slabs. Regular precast concrete compressive strength is taken as 35 MPa, while the UHPFRC joint achieved a strength of 150 MPa. All specimens are made with non-contact lap splices of spacing equal to 200 mm. A total of 6 specimens were tested under four-point load to failure. Four slabs comprised of different bar splice lengths at the joint, namely; 75, 105, 135 and 165 mm; associated with closure strip widths of 125, 155, 185 and 215 mm, respectively. The other two control slabs were reinforced with continuous GFRP bars for comparison purposes. The mechanics of the anchorage behavior are observed and recorded to evaluate the manner in which the capacity of a straight-end GFRP bars is developed. Correlation between the experimental findings and standard design equations is made. Girder spacing recommendations are proposed for the proper closure strip width and strength based on the applied factored design loads on the bridge deck slab.
New Test Method for Reinforced Concrete Pipe Joint Hydrostatic Infiltration (MA56)
Lui Sammy Wong - Con Cast Pipe, Moncef Nehdi - Western University
The hydrostatic performance of reinforced concrete pipe (RCP) depends on the gasket design and its materials properties, the joint design and its quality, the joint dimensional tolerance during pipe manufacturing, and more importantly, the quality of the concrete pipe installation. Existing specifications pertinent to testing RCP joint performance are limited to evaluating the exfiltration of the joint. It ignores the fact that, for a non-pressure gravity sewer, the true requirement for hydrostatic performance is to resist groundwater infiltration. Existing testing standard is only available in the field which is costly and difficult to perform. The test is limited by the groundwater condition. The repair cost is high in the case of failure. There is need to develop a simple yet effective method for gaging the infiltration capacity of the RCP joint at the manufacturing facilities. In the present study, a new testing method is developed to address this need. The proposed method was applied to conventional RCP diameters ranging from 600 to 1200 mm. The test results show that the proposed method provides a scientific and unbiased evaluation of both the joint capacity hydrostatic infiltration and the working external pressure of the joint. Recommendations for future development of a related standard test method are provided.
Keywords: Reinforced; Concrete; Pipe; Hydrostatic; Test; Joint; Infiltration.
Reduction of Bridge Pier Scour Through the Use of a Novel Collar Design (DM2)
Christopher Valela - University of Ottawa, Ioan Nistor - University of Ottawa, Colin Rennie - University of Ottawa
River floods are events which, depending on their severity, can induce serious damage to infrastructure and communities located in their vicinity. One form of damage that is often overlooked pertains to bridge infrastructure such as pier foundations submerged in the riverbed. The increase in flow velocity in such events has been shown to increase the amount of scour around the base of bridge piers, often with damaging consequences for the stability of the piers and, implicitly, of the bridge. As the approaching flow impacts the upstream face of the pier, a portion of it is redirected downwards to the riverbed where it forms a vortex. This vortex continues to develop around the upstream face and sides of the pier, in the shape of a horseshoe, eroding the riverbed material from around the base of the pier. During periods of extreme flooding, larger flow rates within rivers or channels are often experienced and lead to an increase in the intensity of the horseshoe vortex around piers. As a result, larger quantities of riverbed material can be potentially eroded, thus jeopardizing the stability of the pier and therefore the safety of the bridge. Various countermeasures are available to help mitigate this issue but most are largely intrusive, require frequent maintenance, and are only useful under certain conditions.
The study presented herein will introduce an alternative countermeasure, in the shape of a novel three-dimensional collar, which will reduce or eliminate the harmful scour from around the foundation of bridge piers. This collar will be mounted around the base of the bridge pier and rest directly on the riverbed. The purpose of this collar design is to capture the horseshoe vortex that forms on the front and sides of the pier and direct it in the downstream direction, ultimately disallowing it from contacting the riverbed. In doing so, the main scour-causing mechanism is avoided and any remaining shear stress experienced around the pier is dissipated by the collar, therefore protecting the riverbed in the vicinity of the pier. An additional benefit to this new collar is that it can be prefabricated offsite then be easily installed on new or existing bridge piers with little to no harm to the environment. Combining the versatility, minimal maintenance, easy installation, small environmental impact, low cost, and scour reducing capabilities, this new collar design has the potential to greatly improve the way pier scour is currently addressed.
Taking account of landslides in 2D hydrodynamics modeling (GC56)
Ismail Ouchebri - École Polytechnique de Montréal, Mahdi Tew-Fik - École Polytechnique de Montréal, Département des génies civil, géologique et des mines (CGM)
Dam-break floods are characterized by high flow rates, causing the erosion of riverbeds and riverbanks. Riverbanks are subject to geotechnical instabilities, which are often difficult to consider during hydraulics modeling since the available software don’t take account of riverbanks instabilities. This paper aims to propose an approach of combining a slope stability module, BISHOP, with a 2D hydraulics model, SRH2D, to have a completely two-dimensional river modeling. After generating the mesh of the river, BISHOP can be launched through an input data file containing the riverbank profile defined from the pre-established mesh. If a riverbank fails, all the mesh nodes belonging to the sliding area, defined as a slip cone whose characteristics will be fixed based on geotechnical observations, will be automatically updated, allowing a newly defined geometry of the river and its banks. The Ha!Ha! River, in Quebec, will be used for to test the proposed approach. A comparison between the predicted and observed results will be presented and discussed.
Assessment of Rehabilitation Methodologies for Damaged Concrete Bridge Pier (ST54)
Michael Soto Rojas - Tecnológico de Costa Rica, Dan Palermo - York University
A nonlinear finite element numerical study was conducted to simulate the current damage in a bridge pier and to establish the most effective repair/retrofit strategy by means of Fiber Reinforced Polymer (FRP) sheets. The structure under study corresponds to one of the four post-tensioned concrete piers of the Tárcoles River Bridge, located in Costa Rica. The pier has an oval cross-section, 4 neoprene pads as load-transmitting devices between the superstructure and substructure on the surface, and a shear key utilized to transmit lateral forces. During the first stage of the research, a numerical model of the bridge pier was developed to simulate the existing damage. Loads simulating the actual conditions were imposed on the model to generate similar damage to that experienced by the structure (severe cracking in the longitudinal direction of the pier). Thereafter, the model in its damaged state was subjected to a pushover analysis with lateral loading simulating earthquake excitations to determine vulnerability to the design level ground motion. The modelling illustrated that due to the magnitude of the imposed axial load of the superstructure, the bridge pier experienced splitting cracks and dilation. As a result, the shear reinforcement yielded and the predicted cracking pattern was in close agreement with that observed. The pushover analysis demonstrated a substantial reduction of both lateral load and displacement capacities. The widening of the longitudinal cracks and yielding of the shear reinforcement prevented the pier from behaving as a single element, therefore, the stiffness and ductility of the pier in comparison to the design values were reduced. The second stage of the research focused on the viability of repairing the damage in the pier and further strengthening with FRP sheets. An additional nonlinear model was developed based on the damaged model. The repair/retrofit strategy consisted of applying grout injection to seal the cracks; followed by the application of a single layer of FRP jacketing. Subsequently, the retrofitted model was subjected to lateral loading to determine improvements in seismic response. The results reflected an enhanced behavior for the retrofitted pier, including an increase in the deformation capacity. The repair/retrofit suppressed the predicted brittle failure of the damaged pier and restored the lateral load resistance that the pier was initially designed for.
Investigating the Technical and Economic Viability of Integrating Building Performance Monitoring and Measurement (M&M) Systems into Building Information Modeling (BIM) (GC28)
M Shokry Rashwan - Red River College, Randal Peters - Red River College
There remains a disconnect between information describing pre-occupancy conditions of a building and the synthesis of monitoring and measurement (M&M) data essential to manage it during its lifespan. This unnecessary gap causes the construction industry a hefty price in the form of waste and decline in productivity when compared with other industries such as manufacturing and aerospace. A number of reasons have been known to cause such a gap, most challenging of which is the inadequate interoperability among the many digital platforms that are used to generate and manage information at the pre and post occupancy stages of buildings. Building Information Modeling (BIM) presents a potential platform to bridge this gap. This paper provides a summary description of work conducted as a first part proof-of-concept within the context of a larger project to extend the effective use of Building Information Modeling (BIM) beyond design and construction stages into facility commissioning and operation. Specifically, this work investigates the effective integration of building performance monitoring & measurement (M&M) systems into BIM. An existing small laboratory called the “Experimental House” at Red River College was used for this part of the research. Building performance data is collected from disparate third party platforms that generate values for 1) temperature and moisture levels of building components; 2) energy consumption; and 3) indoor environmental quality. These live data streams are integrated with a 3D visualization of a BIM model to provide a facility manager with a holistic view of building performance. The work began with identifying and selecting an effective integration platform. A web server was established to house the platform where a “stripped down” version of a BIM model, using the Industry Foundation Class (IFC) representation, was generated. Examples of different commercial building performance M&M systems were then selected and connected to the model via a developed interface. The focus of the proof-of-concept investigation was to address three issues: First: what are the challenges faced in connecting different M&M platforms to a BIM model and how to mitigate these challenges. Second: how to transform data generated by these different systems into a useful and “fit-for-analysis” format. Third: how to perform changes in the BIM model, if analysis necessitates, and propagate these changes back to keep it as current as possible.
Market Competition and Innovation in the Construction Industry: An Empirical Study to Support Optimal Procurement Strategies (GC132)
Sergiy Polyachenko - University of New Brunswick, Jeff Rankin - University of New Brunswick, Dhirendra Shukla - University of New Brunswick, Yuri Yevdokimov - University of New Brunswick
This research is devoted to identifying markets within the construction industry, assessing the level of competition across those markets and exploring the effect of competition on innovation in the industry. In addition, the role of alternative procurement modes with respect to innovation in the industry is studied. There are several analytical models explaining correlation between competition and innovation. However, very little empirical work has been done to investigate the nature of this relationship in the construction industry. In addition, there is no clear understanding of market boundaries within the construction industry. Existing literature indicates that the major obstacle for innovations in the construction industry is excessive competition and high risks. We identify those markets, compare levels of competition across them, and, by applying an inverse U-shaped version of the theoretical model of step-by-step innovations, we empirically investigate the effect of competition transmission into innovations. The level of competition is assessed through a detailed study of the competition effect on innovations based on survey data collected from the industry participants. The role of alternative modes of public procurement is examined in the context of bringing the level of competition to the optimal value and improving the innovative environment in the industry. Finally, a mechanism of competition optimization employing alternative modes of public procurement is designed as a tool to support market regulation aimed at stimulation of technological progress in the construction industry. Preliminary results obtained from a sample of firms operating in emerging markets of Eastern and Central Europe provide some evidence of the non-linear (inverse U-shaped) relationship between competition and innovation in the construction industry.
Preliminary Framework for the Standardization of Corporate Sustainability Management Systems (CSMS): Part 1 – Background and Theoretical Foundations (GC8)
Cesar Poveda - No Affiliation
A two-part manuscript presents a framework designed for the standardization of corporate sustainability management systems (CSMS) based on theoretical research. Part 1 discusses the background and theoretical foundations of the framework whilst Part 2 proposes the principles, clauses, sections, and sub-sections comprising the basic structure of a CSMS. Management systems (MSs) allow organizations to meet their vision, goals, and objectives through the development and implementation of frameworks, which may target a specific area of performance (e.g., quality, safety, environmental). Policies, processes, and procedures used by the organization are fundamental but not the only elements included in the structure of MSs frameworks. The International Organization of Standardization (ISO) has taken the Management system (MS) concept one step further by developing management system standards (MSS) for several areas of performance with the intent of helping organizations to improve their performance through the implementation of specific repeatable steps and creating an organizational culture engaged in a continuous cycle of self-evaluation, correction, and improvement. Other regional (e.g., European Committee for Standardization [CEN]) or national (e.g., British Standards Institution [BSI], Canadian Standards Association [CSA]) standardization associations either adopt standards released by ISO or develop their own. While the implementation of MSS provides a wide range of benefits, organizations may choose to implement and demonstrate the correct use of MSS or develop and implement standard guidelines without necessarily pursuing a certification from ISO or any other organizations for standardization. ISO and other organizations provide standard frameworks in several areas of performance, but standards addressing corporate sustainability management have yet to be developed. Furthermore, attempts to incorporate sustainability into corporate management processes have been made, but a standalone MSS framework has not yet been presented. As a result, this two-part manuscript attempts to introduce the framework for a CSMS, but recognizes the difficulties encountered due to the roots of the concept of sustainability.
Preliminary Framework for the Standardization of Corporate Sustainability Management Systems (CSMS): Part 2 – Principles, Clauses, Sections, and Sub-sections (GC9)
Cesar Poveda - No Affiliation
Sustainability can no longer be considered a new or static concept. While the concept continues to evolve and increasingly robust theory emerges, organizations are being challenged by the need to implement the principles of a term for which a widely accepted definition remains undetermined. Nevertheless, sustainability has become an influential factor of organizational transformation. Organizations are dynamic entities immersed in a process of constant evolution and adaptation. Given that sustainability is the latest transformational factor forcing organizations to re-evaluate their business strategies in order to address the increasing demands of groups impacted by their actions (i.e., stakeholders), there is a need for developing and implementing management tools to assist organizations in the transformational process. A two-part manuscript proposes a framework for the structure of a CSMS. Part 2 discuses the development of principles, clauses, sections, and sub-sections of the proposed standalone CSMS, for which the framework is based on the examination of the Plan-Do-Check-Act (PDCA) model and the structure of management system standards (MSS) developed by the International Organization for Standardization (ISO). ISO standards have been used in other areas of organizational performance (e.g., quality, environment); however, a standalone standard addressing corporate sustainability (CS) has yet to be designed. In addition to presenting the framework structure (i.e., clauses, sections, sub-sections, requirements), the manuscript proposes the incorporation of two additional phases to the PDCA model. The potential benefits of the CSMS framework are underscored by the already proven and extensively documented effectiveness of other MSS. The development of a CSMS and its subsequent implementation both benefits and assists organizations in executing their sustainability vision and goals while aligning their needs, interests, and expectations with those of the interested internal and external parties. Consequently, this manuscript advances the body of knowledge by presenting a CSMS framework that can be adapted to each organization’s needs while scientists in sustainability management can use the framework to design further management processes with the aim of assisting organizations in the critical task of embedding sustainability principles into the organizations’ business strategies and their short-, mid-, and long-term sustainability vision and goals.
Buried Bridges: More Sustainable, More Durable (GC21)
Raymond Wilcock - CSPI, Paul Proctor - Atlantic Industries Limited
By offering better alternatives to traditional bridges, Buried Bridges now deliver maximum value and road safety. Continuous research, product improvements and more durable coatings have elevated the performance characteristics of buried bridges to the point where they are now legitimate contenders in markets, environments and sites from which they were previously excluded.
From projects across Canada, the resilience of buried bridges has demonstrated their ability to withstand extreme weather events, over time. After surviving severe flooding, and even hurricane events, buried bridges were often the one bridge left standing.
By minimizing the natural and financial resources required, Buried Bridges yield a positive environmental impact. Mitigated durability, hydraulic flows, traffic disruptions and climate change risks are among their accrued benefits; moreover, high recycled content and reduced construction waste make buried steel bridges ideal for Environmental Product Declarations. And maximizing value to owners contributes to benefits for the entire population.
Demonstrating Use of Tire Derived Aggregate (TDA) in Backfilling Home Basement Walls in Manitoba (GC161)
M Shokry Rashwan - Red River College, Peter Schroedter - OTR Recycling/ Resolute Rubber
Based on extensive results from laboratory and small scale experiments, a research investigation progressed into the demonstration stage where a full scale basement of a typical home, using Tire Derived Aggregate (TDA) as backfill and underneath the slab, was built. This part of the project, began early in 2016 and with an end date in early 2018, is focusing on two main tasks the outcome of which will be used to potentially introduce TDA as a green building material into the home building market in Manitoba. These tasks are:
First: Measuring and analyzing the properties that describe the long-term performance of TDA using a multitude of instrumentations and tools as well as developing guidelines for TDA use in this application.
Second: Conducting economic and environmental assessments to address issues such as lifecycle & cost-benefit analysis for use of TDA in this new application.
This case study summarizes the results of two years of monitoring and analyzing the long term performance of using TDA as a replacement of natural material in backfilling home basement walls.
Belmont Trio, Kitchener, ON (GC167)
Kurt Ruhland - MTE Consultants, Inc.
The Trio project consists of one 14-storey, one 12-storey and one eight-storey apartment building with a separate four-storey aboveground parking structure. All of the structures were constructed utilizing total precast construction with only the foundations consisting of cast-in-place concrete. In total nearly 3,500 pieces of precast concrete were erected on the site with 3,250 pieces in the buildings and 229 pieces in the garage. The basic building system consists of hollow-core concrete floor planks supported by precast concrete bearing walls. The building structures are designed with the structural walls aligned parallel to the length of the building using the exterior walls and one corridor wall for bearing. This alignment allowed the exterior walls to serve as both structural support and cladding. As the majority of the exterior walls are load-bearing, there were constraints on openings for windows, louvres and vents that needed to be balanced with the architectural design.
The precast concrete wall panels are either 200- or 250-mm thick and utilize a combination of form-liners and reveals to achieve the concrete finishes. Panels were then stained in the field to achieve the desired colors. The implementation of the staggered balconies was chosen in order to create an iconic architectural expression. The balconies were offset in two-storey increments such that each balcony expression was two floor levels of height before the balcony above it staggered. The aboveground precast concrete parking garage uses a conventional double tee floor system with structural beams, columns, column walls and shear walls.
Precast concrete was chosen for its long-term durability, cost efficiency, for its speed of erection, continuous construction during the winter months and to maintain the project schedule efficiently. On average one floor was constructed each week. As the erected floors included the exterior walls and cladding, each floor was easily enclosed allowing trades to almost immediately start work on the finishing out the units.
Predicting the Usage of Cycling Infrastructure in Cities with Cold Climate (TR16)
Siroos Shahriari - University of Calgary, Farnaz Sadeghpour - University of Calgary
Cycling has gained increased attention among both researchers and public planners in the last two decades as a sustainable means of transportation. Compared to users of other modes of transportation, cyclists are more exposed to weather conditions. For example, harsh weather conditions such as cold temperatures or rain negatively affect an individual’s decision to use a bicycle for transportation. As a result, cycling infrastructure usage changes throughout the year because of highly variable weather conditions. On the other hand, in recent years North American cities try to encourage cycling through the development of cycling infrastructure networks. For that, municipalities require estimates of infrastructure network usage throughout the entire year to make decisions about investments and maintenance costs. However, collecting data for all cycling infrastructure throughout the year is not economically feasible. The objective of this paper is to develop a model capable of predicting changes in cycling infrastructure usage for different months of the year based on observations from only one month. A prediction model will be developed using Generalized Estimating Equations (GEE). Changes in cycling frequency for each month will be predicted relative to a reference month. The usage change will be predicted based on weather variables namely: temperature, precipitation (i.e. rain, snow, hail), collected snow on the ground, wind speed and the number of sunlight hours in a day. As the model was developed, it was noticed that the effect of weather conditions on commuter cyclists and reactional cyclists is not the same. As a result, two separate sub-models will be developed. The first sub-model will be based on weekday usage data which will evaluate the impact of weather conditions on commuter cyclists. The second sub-model will be based on weekend usage to evaluate the impact of weather condition on recreational (non-commuter) cyclists. Additionally, it will be examined to what extent the above-mentioned weather variables are accountable for predicting cycling infrastructure usage. The developed model can help cities and municipalities in decision making on investments, maintenance and modifications to the cycling infrastructure.
Impact of Substance Abuse on Construction Workers (GC171)
Md. Safiuddin - George Brown College
Fifty willing construction workers at 15 different construction sites were asked to fill out the survey regarding substance abuse. The construction sites were picked based on location proximity, and upon arrival at the site, the workers were asked to participate in an anonymous survey. Those willing were provided with the survey and allowed 10 minutes for completion of it. The majority of the construction sites were in Richmond Hill and Thornhill, with a few sites in North York. The survey consisted of two portions: questions regarding the demographics of the study participants and questions regarding their substance use habits. The demographics were aimed at understanding whether certain factors such as age, level of education and marital status influence the tendency for substance use. The questions regarding substance use habits were designed in a way to understand certain concepts such as most commonly used substances, frequency of use, reasons for the use of substances and how substance use helps the workers in their work environment. The data from all the 50 construction workers were compiled in Microsoft Excel and analyzed using summary statistics and descriptive analysis. By comparing the responses of different workers, the trends in factors contributing to substance abuse were noted; furthermore, the frequency, relative frequency, and mode were calculated for each question.
Potential Applications of Self-cleansing Nano Lotus Leaf Coating in Different Construction Sectors (MA61)
Md. Safiuddin - George Brown College
Lotus leaf has a nanostructure with randomly oriented cone-like protrusions. The nanostructured lotus leave surface possesses an extremely high water-repelling capacity due to super hydrophobic property. This is well-known as “lotus effect”. The "lotus effect" makes nano lotus leaf coating suitable for applications in different construction sectors. The present study highlights the possible applications of nano lotus leaf coating in various construction sectors. The benefits of nano lotus leaf coating are emphasized. More focus is given on the protective role of nano lotus leaf coating when applied on different substrates. In particular, the self-cleansing effect of nano lotus leaf coating is focused to reveal its applicability in different construction sectors. In addition, the self-cleansing mechanism of nano lotus leaf coating for the protection of substrates is explained with illustrations. This study also includes the types of substrate, the techniques for the preparation of substrates, and the application methods for installing nano lotus leaf coating on various substrates. Above all, some recommendations are given to improve the performance of nano lotus leaf coating.
Fire Performance of Screwed Built-Up Glulam Box-Section Beams (ST23)
Nishant Verma - Lakehead University, Sam Salem - Lakehead University
The main objective of the experimental study presented herein this paper is to investigate the structural behaviour of built-up glulam box-section beams under four-point flexural bending at both ambient and elevated temperatures. A total of four 3000-mm simply-supported beam assemblies were experimentally examined: three of them were tested at ambient temperature and one beam assembly was subjected to CAN/ULC-S101 standard fire. Self-tapping screws were used in three different patterns to form the three beam assemblies tested at ambient temperature. Each beam built-up section was made of four glulam panels, each of 44-mm thickness except the bottom flange panel which had 86 mm thickness. Ambient testing showed that reducing the spacing from 800 mm to 200 mm for the screws connecting the built-up section’s top and bottom flange panels to the web panels increased the beam flexural bending strength by about 45%. While reducing the spacing from 200 mm to 100 mm only for the screws connecting the bottom flange to the web panels over a distance equal to one-third beam span length from each support, where the maximum shear stresses existed, increased the beam flexural bending strength by an additional 10%. Only the strongest beam assembly was tested under the effect of standard fire while subjected to monotonic loading that resulted in a bending moment equivalent to the beam’s full resistance design moment calculated at ambient temperature. Fire resistance testing revealed that such built-up glulam box-section beam can sustain the applied design load under standard fire exposure for slightly more than 30 minutes with no fire protection.
Case Study: From Fredericton to Fray Bentos (GC178)
Daniel Scott - ADI Systems
FROM FREDERICTON TO FRAY BENTOS Daniel B. Scott1, M. Scarlett Zelaya1, Mike Greer1, José A. Molina1, Shannon R. Grant1 1 Evoqua Water Technologies, 370 Wilsey Road, Fredericton, New Brunswick, Canada E3B 6E9 Introduction Alimentos Fray Bentos is a new plant by La Sibila in Fray Bentos, Uruguay that produces value-added dairy products, primarily demineralized whey. Wastewater from this plant must be treated to stringent standards prior to being discharged to the Uruguay River. ADI Systems was selected to provide process and detailed design engineering, to supply key components of the wastewater treatment system, and to oversee the start-up. GTI provided the cover and liner and over-saw the installation of internal piping and membrane units. The treatment system consists of two main stages: anaerobic digestion to remove the majority of the organic load with minimal energy requirements, followed by a polishing stage to meet tight discharge limits (including for nutrients). The ADI-BVF® low-rate anaerobic reactor has more than 30 installations treating wastewater from dairy processing industries so it was a well-proven choice for the first stage. For the second stage, a membrane bioreactor (MBR) was selected based on the tight limits that had to be met. Design of the System Table 1 presents the design wastewater characteristics for this treatment system. It has a hydraulic capacity of 1 025 m3/d, with provision for expansion to 1 600 m3/d. The design organic loading is 4 300 kg/d as COD (3 050 kg/d as BOD). The anaerobic stage is intended to achieve 85% COD removal, with the aerobic stage providing polishing for the remainder of the organic load and ensuring low TSS in the effluent due to the physical barrier of the submerged membranes. The aerobic stage also needs to remove nutrients to low levels: 10 mg/l for nitrogen and 0.1 mg/l for phosphorus in the effluent. Table 1. Design characteristics of raw wastewater, anaerobic effluent, and MBR effluent Parameter Influent Anaerobic Effluent MBR Effluent Flow (m3/d) 1 025 --- --- Total COD (mg/l) 4 200 630 < 75 BOD (mg/l) 2 975 300 < 10 TSS (mg/l) 200 200 < 2 TKN (mg/l) 75 65 --- NO3-N (mg/l) --- --- < 10 TP (mg/l) 29 25 0.1 Calcium (mg/l) < 100 --- --- Temperature (°C) 25 – 35 25 – 35 --- The ADI-BVF® reactor was constructed as a lined earthen basin with a concrete perimeter wall and a floating
Behaviour of Fibre Reinforced Polymer Reinforced Concrete Beams with Fibre Mesh Shear Reinforcement (ST64)
Douglas Tomlinson - University of Alberta, Mridul Shahi - University of Alberta
Fibre-reinforced polymer (FRP) reinforcement has been effectively used as replacement for steel in concrete structures for at least 25 years. Although there are many benefits to using FRP reinforcement, particularly corrosion resistance, it cannot be bent after fabrication. In construction, this causes issues on site since field adjustments cannot be made as easily as they can with steel reinforcement. This study investigates the constructability and effectiveness of a flexible fibre mesh as shear reinforcement in FRP reinforced concrete structures. Although this shear reinforcement type is mentioned in the most recent Canadian FRP design code (S806-12), there are limited published studies on the behaviour of this material as shear reinforcement.
The effectiveness of fibre mesh as shear reinforcement was evaluated using twelve 1200 mm long, 156 mm deep concrete T-beams tested under four-point bending. Test parameters included longitudinal reinforcement (glass FRP with reinforcement ratio = 0.75%, glass FRP with reinforcement ratio = 1.19%, and steel with reinforcement ratio = 1.18%) and shear reinforcement type (steel stirrups with shear reinforcement ratio = 1.51%, 25x25 mm basalt mesh with shear reinforcement ratio = 0.12%, and no shear reinforcement).
A small aggregate (6 mm) and high slump concrete mix was used to fabricate the beams since the mesh aperture size is small (25x25) mm. The mesh was easily cut to size with scissors; the small (~2 mm diameter) mesh strands ensured that there were no development length issues or premature failures at bends.
The fibre mesh increased shear resistance relative to beams without shear reinforcement. This effect was higher (average 54% increase) for beams with a small reinforcement ratios compared to the beams with larger reinforcement ratio (average 13% increase). Similar increases were seen with deformability and deflection at failure. S806-12 drastically underpredicted the failure load of beams that failed in shear. For instance, Glass FRP reinforced beams with basalt mesh shear reinforcement were 73±12% stronger than CSA predictions. However, the low shear reinforcement ratio of the fibre mesh limited its effectiveness relative to beams with steel stirrups and shear failure still occurred in all fibre mesh reinforced beams.
The results of this study indicate that fibre mesh can be effectively constructed and used as shear reinforcement in concrete structures. Future studies will investigate larger beams with higher fibre mesh reinforcement ratios.
Durability of Advanced Cement-Based Materials Used as Repairs for Deteriorated Concrete (MA19)
Keikhosrow Tahmureszadeh - Ryerson University, Medhat Shehata - Ryerson University
With advanced technology and knowledge in the concrete industry, production of strong and durable construction material becomes more feasible. However, use of such materials as repairs on top of existing concrete (substrate) is challenging. There are limited research on the durability and sustainability of bond strength under cycles of freezing and thawing in the presence of de-icing salt. Hence, this research is designed to evaluate and compare the bond strength of two repair materials – commercial specialized repair material with self-consolidating properties (SRM) and normal conventional concrete (NC) – casted on top of NC substrate. In order to achieve this objective, the study adopts three different evaluating test methods (pull-off, slant shear, and splitting tensile) with different surface texture (rough and smooth) through four cycles of freezing and thawing with de-icing salt (0, 5, 15, 25). The results showed that although the bond strength for SRM initiated at a higher value for all the evaluating tests, its value started to decline significantly compared to the NC under the effect of freezing and thawing in the presence of de-icing salt. Running statistical T-test analysis demonstrated that the difference between rough and smooth surface is statistically significant with the rough surface showing higher bond strength in all.
Understanding the Factors Affecting Expansion Due to Alkali-Silica Reaction in Concrete (MA60)
Noura Sinno - Ryerson University, Medhat Shehata - Ryerson University
Alkali-silica reaction (ASR) is a chemical reaction in concrete resulting in expansion, cracks and disruption of concrete elements. Many researches have been performed to find preventive measures to mitigate the damage. The use of supplementary cementing materials (SCM) is one of the common measures leading to the reduction in expansion due to ASR. Minimum levels of SCM needed to counteract ASR are provided in the Canadian standards, CSA A23.2-27A. These levels are obtained based on the concrete prism test (CPT) described in CSA A23.2-14A. However, at later ages, expansion in the field was found to be higher than the expansion obtained using the CPT at 2 years. A number of reasons could be behind this finding, such as alkali leaching from samples. However, there is no clear understanding of the observed differences in expansion. In this research, the focus is to study the effect of sample geometry and temperature on the alkali leaching and expansion. Cylinders and cubes were studied in addition to the standard prisms at two temperatures, 38°C and 60°C, using two aggregates of different reactivities: Sudbury and Spratt having one-year expansions of 0.17% and 0.23% respectively. Leaching of alkalis from the samples as well as expansions were measured. Results showed that larger samples have less leaching compared to prisms for both aggregates. However, for samples with SCM, cylinders casted with Sudbury aggregate showed higher expansion than prisms which was not the case with the cylinders casted using Spratt aggregate. The expansions of prisms and cylinders are similar for Spratt samples with SCM. This explains that not only the sample geometry affects the ASR expansion but also the aggregate type. The dependence of a particular aggregate on certain level of pore solution alkalinity is an important factor that should be taken into consideration. In addition, results showed more leaching of alkalis from samples at higher temperature. At early ages, the expansion at 60°C was accelerated for all the different sample geometries compared to samples at 38°C. The ultimate expansions of the control samples at 60°C were lower than the ones at 38°C as expected based on the leaching results. Although at 60°C the leaching was higher for the samples with SCM compared to the samples at 38°C, however the expansions at both temperatures were the same. Possible reasons for this finding are presented and explained.
Development of a New Method for Underground Structure Modeling and Design (GC32)
Shahram Shekarriz - RahSaz Tarh Consulting Engineers, Payman Yousefi Mojir - RahSazTarh Consultin Engs.
Underground urban railway systems have a great influence on transportation industry because it reduces traffic by providing an individual route and increasing efficiency of the network as well as reduction of pollution. One of the biggest challenges in underground urban railway design is providing safe and economical design of stations at the same time due to the limited budget and high number of stations. Hence, accurate analysis and design is very important. This paper introduces a new modelling method by which has been examined Tehran Metro projects. On the other hand, based on model results and economical requirements an optimized structure analysis has been performed.For design optimization, two methods are described for underground railway station design. The first method considers risk assessment to select the best structural system and proper ways of soil stabilization through which reduces surface settlements up to allowable range. This procedure can be introduced as a modified NATM. By this method, a real design example including the comparison of the results with old construction method system (pile & rib) is compared. The second method presents a guideline to estimate the minimal rebar area required in sections which is crucial to maintain the serviceability of structures for 100 years and reduce the construction costs due to the scale and dimensions.
developing an approximate approach for vibration and noise analysis combining FEM and FTA guideline (GC79)
Shahram Shekarriz - RahSaz Tarh Consulting Engineers, Payman Yousefi Mojir - RahSazTarh Consulting Engs.
Railway systems are one the most important transportation methods through which many authorities can provide sustainable development in their considered region like an urban area. However, like every other system, this kind of transportation may have some drawbacks by which affect the quality of life for neighbor residents. Annoying noise and vibration induced by passing trains is a significant problem in urban areas so many efforts have been done in order to calculate and reduce them. FTA (Federal transportation administration) guideline provides criterion based on field experiments to calculate the future vibration levels. This method is mostly based on field vibration tests and it could be too expensive for large railway projects in which the length of the project is considerable. Because in most cases it requires to provide lots of transmission measurements as well as force density measurements. in this study FTA criterion have been simulated using finite element method and FEM parameters related to soil properties have been extracted from FEMA, ACI and FHWA. Dynamic behavior of soil, especially soil damping, is too substantial in this finite element modeling and damping of the soil in the model and real soil must be the same. Using a simple algorithm based on IBC and ISO and by consideration of soil dynamics and dynamics of continuous media, a finite element model has been developed and verified by field tests. Using this procedure, it is possible to validate the efficiency of different vibration reduction measures and select the right alternative. It must be noted using this method calibration of a model with real situation is possible by varying of model parameters.
Sustainable AnMBR Treatment of Industrial Wastewater: Fouling Control (EN11)
Joshua Snowdon - University of New Brunswick, Kripa Singh - University of New Brunswick
An external AnMBR equipped with a nanofiltration tubular membrane module was operated for 577 days treating a synthetic wastewater simulating a high strength industrial wastewater. The organic loading rate supplied to the AnMBR was in the range of 0.8 – 8.2 kg/m3d, with a mixed-liquor suspended solids (MLSS) concentration in the range of 13.6 – 33.9 g/L. The first membrane module was operated for 166 days of data collection, where the loading limitations of the reactor were gauged. On days 166 – 170, the first membrane module underwent 5 chemical cleaning processes to alleviate membrane fouling and recover its flux. These successive chemical cleanings applied 5 different cleaning methodologies in an effort to analyze their efficiencies in membrane fouling removal. On day 170, a new membrane module was placed into the system to replace the used membrane module. This membrane module was operated for 407 days, 175 of which were used as a separate membrane fouling rate reduction study. Over its course of operation the secondary membrane module underwent 6 chemical cleanings. General results from the chemical cleanings of both membrane modules concluded that a chemical clean with a 1% sodium hydroxide and a 1% hypochlorite solution, without backwashing processes, offered the greatest clean water flux recovery over all other chemical cleaning methodologies (other chemical cleanings consisted of: a 10% citric acid clean, a 1% hypochlorite clean, a combined citric acid, sodium hydroxide, and hypochlorite clean, and some of these chemical cleaning processes also incorporating a backwashing phase). The 10% citric acid cleans, as well as the citric acid cleaning portion of the combined chemical clean, were found to decrease recoverable clean water flux. Additionally, it was found that when chemical cleaning processes took place during a period of operation where a regular chemically enhanced backwash (CEB) took place (the CEB being a portion of the membrane fouling rate reduction study) membrane flux recovery following a chemical cleaning increased. If chemical membrane cleaning processes could be enhanced and better understood they could help further justify AnMBR applications. A better understanding of chemical cleaning protocols is required to reduce the quantities of chemical agents used and quantify the relationship between sequential chemical cleanings and reversible fouling removal efficiency. As membrane costs will always be an important constraint in AnMBR applications, prolonging the longevity of a given membrane module through efficient chemical cleaning processes is critical to their success.
Evaluation of a Low-Cost Drone for Monitoring Restoration of Oil and Gas Well Pads (EN6)
Kalie Smith - University of British Columbia, Dwayne Tannant - University of British Columbia
Oil and gas development activities disturb the land surface at former well pads. These sites must be restored upon decommissioning and this process takes several years to accomplish. Fieldwork was conducted in 2017 to evaluate use of a small low-cost drone for measuring and assessing reclamation at four well pads on crown land near Hudson’s Hope, BC. These sites had an “abandoned” status for one year, were under the same operator, and had not yet received a Certificate of Restoration.
A DJI Phantom 4 Pro drone was flown over each well pad in July 2017 and again in September 2017 to capture a series of photographs. The drone flew pre-programmed flight paths with a specified height and grid pattern. The photos were used to compare the states of reclamation over time, and to explore ways to quantify the state of reclamation under field conditions. The photos show significant increases in vegetation over the two month period. Using existing photogrammetry tools ortho-photographs, contour plots, and surface models were generated to identify the impact of slope and drainage on vegetation density. The photos can also highlight areas with less vegetation, which can prompt investigation for contamination, or comparison with where equipment on the well pad was located when development activities were taking place, and if this impedes growth.
A fifth well pad was also flown that is inaccessible by vehicle as the access road is mostly reclaimed. The drone was flown a short distance along the access route to capture photos of this well pad, confirming that drones can be used to assess reclamation of well pads that are otherwise inaccessible for inspection.
This paper presents the results of the investigation and discusses the advantages and limitations of using drones for reclamation assessment purposes. The objective is to document best practices for using a drone to assess reclamation practices, which in turn can be useful for well operators in seeking a Certificate of Restoration for their well pads. Using drones to assess restoration of well pads can be more efficient and provide better data compared to manual inspection at the ground surface.
Effect of Aging and Compaction Magnitude on Swelling Characteristics of Rubber Modified Asphalts (MA28)
Mansour Solaimanian - The Pennsylvania State University
Use of crumb rubber in asphalt has been experienced for several decades. There has been extensive research on rubber modified asphalts and many pavements have been built using this material. In general, use of rubber in asphalt has been shown to be beneficial both from environmental point of view (landfill saving) and field performance (reduction in rutting and increase in fatigue resistance). A challenge faced with rubber modified asphalts is the swelling of rubber particles, and the rebound of the compacted specimens. This phenomenon is more severe in the dry process (when rubber is blended with the aggregate); however, it does also pose a challenge in the wet process (when rubber is blended with asphalt). Such behavior affects mechanical properties of the mix, and results in reduction of density in the field. A laboratory experiment was undertaken to quantify the level of this swelling and to determine if the magnitude of specimen swelling was affected by the aging level and compaction energy when the wet process is utilized. The experiment was also conducted in a way to separate the effect if rubber swelling on specimen rebound from the effect of compaction energy on this rebound. The study indicated that extended aging reduces the specimen swelling significantly. Similarly, higher rebound was observed under higher compaction energy. Specimens were prepared under short term and long term aging processes and compaction was conducted using a gyratory compactor at different energy levels. Finally, the mix swelling and rebound were correlated with the rubber modified binder characteristics through tests such as multiple stress creep and recovery (MSCR) and linear amplitude test (LAS) conducted on the binder. The findings of this study are significant assisting the mix designer with a tool for better control of the mix behavior and reduction of swelling both in the laboratory and in the field.
Impact of Natural Organic Matter (NOM) on Adsorption of Target Metals from Industrial Stormwater Runoff (EN7)
Sadman Soumik - Dalhousie University, Margaret Walsh - Dalhousie University
Contaminated stormwater runoff from industrial sites can contribute significantly high organic and inorganic pollution mass loads to receiving surface water bodies. Metals, such as cadmium(Cd), iron(Fe), manganese(Mn) and zinc(Zn) can accumulate in living tissue, and unlike organic wastes, metals are non-biodegradable. The objective of this study was to evaluate the impact of natural organic matter (NOM) on the adsorption of target metals from industrial stormwater runoff. Two waste-by-products from the iron and steel manufacturing sector were evaluated in terms of their adsorption capacity for metal removal from the test water in this study: (1) Open-Hearth Slag(OHS) and (2) Air Cooled-Blast Furnace Slag (ACBFS). Bench-scale batch adsorption experiments were conducted using a shaker table and synthetic stormwater runoff simulated according to a sampled stormwater runoff from a Biomass Power Generation facility in Nova Scotia, Canada. 200mL of the synthetic runoff water spiked with humic acid TOC= 40 mg/L) and control with no humic acid (TOC= 0 mg/L) were dosed at low (10 g/L) and high (35 g/L) OHS and ACBFS concentrations. Batch adsorption experiments were also conducted with Granulated Activated Carbon (GAC) of 1 mm particle size at doses of 10 and 35 g/L for comparison with the OHS and ACBFS material. After shaking for a 24-hour period at room temperature, each flask was removed, and the water was settled for 30 minutes. Results of this study showed that more than 90% of Cd, Fe, Mn, and Zn was removed from the water phase with ACBFS and OHS addition at the higher dose. Adsorption capacity of OHS and ACBFS was found to be higher in control experiments (TOC = 0 mg /L) compared to experiments conducted with the test water at higher TOC concentrations (40 mg/L). Comparatively, GAC did not perform as well as OHS and ACBFS for the removal of the metals evaluated in this study.
Design and analysis of controlled rocking steel braced frames for seismic hazard in Canada (ST78)
Taylor Steele - McMaster University, Lydell Wiebe - McMaster University
Controlled rocking steel braced frames (CRSBFs) have been proposed as a low-damage seismic force resisting system with self-centering capabilities. The force-limiting mechanism is rocking at the base, where energy dissipation may be provided to limit peak displacements, and post-tensioning provides self-centering, a positive post-uplift stiffness, and displacement capacity after rocking. All of the frame members are therefore capacity-protected elements, and are ideally designed to remain elastic after design-level earthquakes. The performance of these systems has been evaluated extensively for regions of high seismicity in the western United States, but little insight is available on the benefits of constructing buildings in the high-risk areas of Canada using CRSBFs.
This paper presents the design of three example CRSBFs for six-storey structures located in Vancouver, BC; Ottawa, ON; and Montreal, QC. The energy dissipation and post-tensioning components that control the performance of the base rocking joint are designed to resist the overturning moment using the equivalent lateral-force procedure. A simple dynamic procedure is used to estimate the contribution of the higher modes to the capacity-design forces for the frame members. The resulting frames are designed for lower lateral forces than would be acceptable for traditional lateral force resisting systems, so little post-tensioning and energy dissipation is required. The nonlinear time history analyses using ground motions selected to match the uniform hazard spectra show that the frame members in the CRSBFs remain damage-free during the ground motions, and that the median interstory drifts are much less than 2.5%.
A Novel Structural System Finds Applications as a Mechanically Joined Foundation Frame for New and Retrofit Construction (ST20)
William J. Vangool - TRIODETIC
Climate change is increasingly affecting the long term serviceability of structures, especially those structures in first nations northern communities located on permafrost and discontinuous permafrost type of soil conditions. A mechanically joined foundation frame has shown to provide torsional stability and resist differential settlement, ensuring the structural integrity of the buildings constructed upon it. Ongoing site observations and evaluations in excess of 30 years have proven that this mechanically joined three dimensional grid can be relied upon as a viable foundation system for a wide spectrum of uses, including retrofit.
Applications of this Canadian foundation system can be found in Northern Canada, Alaska, Norway and Russia. The system is also being used in problem soil regions of California, Regina and recently in downtown Vancouver for a three storey housing facility.
AUTHOR: William J. Vangool, P.Eng, MCSCE, FCAE