- Montreal 2019
- Fredericton 2018
- Vancouver 2017
- London 2016
- Regina 2015
- Halifax 2014
- General / Générale
- CSCE 2014 General Conference / Congrès général 2014 de la SCGC
- 13th International Environmental Specialty Conference / 13ème Conférence Internationale spécialisée sur l'environment
- 4th International Structural Specialty Conference / 4ème Conférence Internationale spécialisée sur les structures
- 10th International Transportation Specialty Conference / 10ème Conférence Internationale spécialisée sur les transports
- Montreal 2013
- General / Générale
- Congrès général 2013 de la SCGC / CSCE 2013 General Conference
- 4th Specialty Conference on Coastal, Estuary and Offshore Engineering / 4ème Ingénierie côtière et en milieu maritime
- 3rd Specialty Conference on Material Engineering & Applied Mechanics / 3e Conférence spécialisée sur le génie des matériaux et mecanique appliquée
- 4th Construction Specialty Conference / 4e Conférence spécialisée sur la construction
- 3rd Specialty Conference on Disaster Prevention and Mitigation / 3e Conférence spécialisée sur la prevention et la mitigation des désastres naturels
- The 2nd Forum on Professional Practice and Career Development / 2e Forum sur la pratique professionnelle et le développement de carrière
- SMSB 2018
Papers - 2015 CSCE Annual Conference Regina - Building on our Growth Opportunities
Improved Sensitivity Analysis in Civil Engineering Design Using Statistical Design of Experiment (DOE) Methodologies
Leonard Lye, Amgad Hussein, Rajib Dey
Dr. Leonard Lye, Memorial Uiversity of Newfoundland (Presenter) Dr. Amgad Hussein, Memorial University of Newfoundland Mr. Rajib Dey, Memorial University of Newfoundland
An engineering analysis or design is seldom complete without conducting a sensitivity analysis. Sensitivity or what-if analysis is the assessment of the consequences of changes due to uncertainty in input factors and/or model parameters on the response of interest, not taking into account information on the probability of these changes. Â By quantifying the sensitivity, one can make design decisions by knowing which input factors have the most influence on the output or response. In practice, changing one factor or one parameter at a time is perhaps the most popular and well-known method for conducting sensitivity analysis. This approach has been advocated and described in textbooks on engineering design as well as engineering economics. The advantage of this method is that it is easy apply and the results are easy to understand. However, the one-factor-at-a-time or OFAT method is known to be inefficient and ineffective and in some cases lead to wrong results. In this paper, an improved sensitivity analysis based on statistical design of experiments (DOE) in combination with regression analysis is introduced using several examples from geotechnical and structural engineering, and an example from engineering economics. This paper will show that with the availability of modern DOE software, the DOE approach is easy to apply, efficient, and interpret. The DOE approach is in fact a combined sensitivity and scenario analysis. It will also be shown that the DOE approach provides better information for decision-making than the OFAT and the stochastic risk analysis approaches.
REAL TIME CONTROL OF COMBINED SEWER OVERFLOW IN EDMONTON
Hongliang Wang, Sid Lodewyk, Liliana Malesevic
Mr. Hongliang Wang, City of Edmonton, Calgary (Presenter) Mr. Sid Lodewyk, City of Edmonton, Canada Ms. Liliana Malesevic, City of Edmonton
CSO (Combined Sewer Overflow) has negative impacts on the environment due to the pollutants contained in the diluted sanitary flow carried to the river. CSO to the river may have acute effects for the river downstream of the discharge point. About 80% of the annual CSO discharge from the city is from the Rat Creek CSO. The City of Edmonton’s Drainage Services has developed a long-term capital works implementation plan to reduce the environmental impacts of the City’s combined sewer system. The CSO Control Strategy will mitigate the environmental impacts of Edmonton’s combined sewer system. The CSO control plan includes an early action plan and a long term control plan. The main component of the Early Action Control Plan (EACP) involves the mobilization of in-line system storage through the “Real Time Control” of moveable gates/dams. Two real time control gates, RTC4&6, were built in 2002 and 2004, respectively. Another real time control gate, RTC3 has just built and currently under operational. Since RTC4&6 were built, a total of 3,615,376 m3 flow has been prevented from CSO at Rat Creek. The CSO at Rat Creek will be reduced significantly with RTC3’s operation.
Construction Engineering and Management
A distributed temperature sensor network to measure and infer frost penetration.
Robert (Bob) McLeod, Marcia Friesen, Blake Podaima, James Blatz
Dr. Robert (Bob) McLeod, Faculty of Engineering, University of Manitoba (Presenter) Dr. Marcia Friesen, University of Manitoba Mr. Blake Podaima, University of Manitoba Dr. James Blatz, University of Manitoba
Municipal water supply line freezing is a seasonal problem in cold-climate areas. In 2014, Winnipeg had over 2300 homes' municipal water supply lines freeze, generally at depths of 8ft below grade and often beneath roadways or other areas not insulated by snow cover. Upon having supply lines thawed, residents were required to run their taps into late June to prevent refreezing, as frost continued to penetrate downward well after ambient temperatures had turned moderate in the springtime. A system of distributed sensors were installed to monitor ground and water temperature. The objective is to demonstrate a means to pre-emptively predict potential service interruptions due to supply line freeze-up. Temperature sensors were installed at grade, at 8 feet below grade, and at the ingress to the residence at the water meter to monitor water supply line temperatures in the City of Winnipeg. The prototype employs Arduino based LM35 temperature sensors with data transmission over wireless (XBee) as well as five commercial thermistor sensors (Lascar) with cloud data collection over Wi-Fi. Data integration includes weather data from Environment Canada, estimated frost penetration from the City of Winnipeg Water and Waste Department, as well as the sensor data collected directly. As of January 15, 2015, fitting the below grade temperature data with a second order polynomial predicts temperatures 8 feet below grade to reach approximately 4 degrees Celsius in mid-April. In January 2015, water supply temperatures of approximately 4 degrees C were consistently cooler than the surrounding ground temperatures.
A FRAMEWORK TO QUANTIFY THE IMPACT OF COLD WEATHER ON NEIGHBORHOOD ROAD DEVELOPMENT SCHEDULE
Monjur Panna, Ahmed Bouferguene, Mohamed Al-Hussein
Mr. Monjur Panna, University of Alberta (Presenter) Mr. Ahmed Bouferguene, University of Alberta Dr. Mohamed Al-Hussein, University of Alberta
City authorities and roadways agencies in winter regions impose restrictions on neighborhood roadway construction activities based on severity of weather. The limitations are imposed mainly to avoid inadequate compaction of asphalt that results in poor performance of roads. Weather fluctuations during late fall season cause delay in work and extend project schedule. As a result, significant increase in development cost is observed due to long-term project overhead and idle equipment costs. In the construction industry, there are examples of successful paving works at severe weather using innovative technologies and materials. However, the construction professionals have to take decision based on the cost benefit analysis of these two options: i) select any of these technologies to avoid schedule extension, ii) wait for the allowable weather. This paper attempts a study of the weather limitations on the asphalt paving works, demonstrating its application to a neighborhood road construction project in Greater Edmonton, Alberta, Canada. It proposes a framework to quantify the impact of these limitations by using the historic weather data and developing a simulation model of paving work to analyze the change of construction schedule while ensuring the asphalt performance in severe weather. The outcome of this study can be used to develop a model for cost benefit analysis of a neighborhood development work.
A Unified Knowledge-based Contractor Prequalification Methodology for the Egyptian Construction Industry
Ibrahim Abotaleb, Ahmed Alkady
Mr. Ibrahim Abotaleb, The American University in Cairo (Presenter) Mr. Ahmed Alkady, Cairo University
Contractor prequalification is an important process that plays a significant role in ensuring successful construction projects. Since the construction industry in Egypt has been booming after two political revolutions, contractor prequalification is becoming more and more essential as it ensures the tenders are targeted to the proper contractors; thus focusing the efforts on the fittest competing firms. The prequalification process is usually managed by project managers assigned by the clients. By interviewing professional experts and studying the different prequalification processes and criteria of various Egyptian project management firms, It was highly noticed that almost all of them are made on ad hoc basis with no strong academic or professional grounds as the currently used criteria are poorly understood. This paper presents the results of an extensive research that concludes by providing a unified prequalification methodology for the Egyptian construction industry. The methodology is divided into four sections. Section 1 identifies and describes the proper criteria for evaluation. Section 2 proposes the appropriate weighing of criteria for different project types and sizes. Section 3 explains objectifying and unifying the scoring approach of each of the criteria. Section 4 provides the final scoring formula and decision-making assistance.Â
AN INNOVATIVE ACCELERATED BRIDGE CONSTRUCTION APPROACH USING PRECAST PANELS, FIBRE-REINFORCED POLYMERS BARS AND ULTRA HIGH PERFORMANCE CONCRETE
Damanpreet Grewal, Nolan Coutinho, Alexander James, Behnam Safarinia, Megan Jakel, Sameh Salib, Khaled Sennah
Mr. Damanpreet Grewal Mr. Nolan Coutinho, Ryerson University Mr. Alexander James, Ryerson University Mr. Behnam Safarinia, Ryerson University (Presenter) Ms. Megan Jakel Dr. Sameh Salib Dr. Khaled Sennah, Ryerson University
The need for enlarging the extents and capacity of existing transportation structures has been growing rapidly worldwide during the past decade. Meantime, minimizing the impact on traffic and shortening the construction duration pose significant challenges to jurisdictions, engineers and contractors. This paper presents a project for widening an existing two-lane bridge over a major water stream within the Great Toronto Area (GTA). Two additional lanes are needed to improve the vehicular traffic flow of the road crossing the water stream. The subject bridge and its proposed widening are of a semi-integral abutment type. This type of bridges is characterized with high durability of both superstructure and substructure components. Two deck systems utilizing Steel I-girders and Steel Box-girders were examined in order to achieve an optimum bridge design. Some of the various challenges were to maintain the existing bridge functional during construction and to keep the river beneath flowing free of any falling debris. Further, high durability measures were considered for the widening structure along with a reduction of the construction schedule within a reasonable budget. Therefore, the design/construction criterion focused an innovative accelerated construction approach in order to satisfy such challenging demands. Through such approach, a deck system of precast concrete panels reinforced with Glass Fibre-Reinforced Polymers (GFRP) bars and jointed, on site, with Ultra High Performance Concrete (UHPC) is proposed. The proposed construction methodology complemented by such advanced construction materials to accommodate the technical and financial measures of the project from both short and long term aspects.
Augmented and Virtual Reality in Combination with Unmanned Aerial Vehicles: A Literature Review
Laird Ferguson, Lloyd Waugh
Mr. Laird Ferguson, University of New Brunswick (Presenter) Dr. Lloyd Waugh, UNB
Augmented and Virtual reality technology has grown rapidly in recent years, as well as the application of Unmanned Aerial Vehicles (UAV) in civil engineering. The documentation of projects delivers wide spread benefits and the addition of aerial images to current documentation processes has potential. The potential in aerial documentation initiated the authors to conduct a literature review on UAVs and how they may be integrated with augmented and virtual realty interfaces. Â This article will focus on the state of the art application of UAVs to capture aerial images in various civil engineering fields such as construction management and transportation. The current civil engineering use of UAV aerial images consist of creating 3D models and point clouds, simple data collection, surveying, monitoring, construction safety, and more. VRDoc, D4AR, and VIRCON are interfaces that can provide up to date documentation of a project. VRDoc provides users the ability to complete virtual site visits, detailed photographic documentation, the opportunity to resolve project conflicts, and training opportunities. All of the interfaces have shown great success in industry applications and further improvements, testing, and implementation are required. Related studies have developed frameworks and methodologies for testing and development of augmented and virtual models. Experimental methodology of quasi-experimental designs are common for studies that do not have full control of all variables in the experiment, therefore making it an appropriate methodology in a construction setting. With a developed methodology the authors will pursue further research into UAV applications with augmented and virtual reality interfaces.
Automated Construction Progress Monitoring using Thermal Images and Wireless Sensor Networks
Mehdi Pazhoohesh, Cheng Zhang
Mr. Mehdi Pazhoohesh, Xi'an Jiaotong-Liverpool University Dr. Cheng Zhang, Xi'an Jiaotong-Liverpool University (Presenter)
Construction progress monitoring has been perceived as one of the key factors that prompt the achievement of a construction project. However, assessing the progress is time consuming, costly and obliges specialized personnel to reduce disagreements and approximate the actual performance to the original plan as close as possible. Image processing is a promising method that has been developed for automated monitoring of construction projects. It has attracted increasing attention for progress monitoring, quality assurance and work space analyses. Nonetheless, remarkable drawbacks still remain in image processing, particularly for outdoor environment such as construction progress monitoring. The principle downside of image processing goes back to the image resolution. Ambient lightning condition significantly affects the image quality which does affect the accuracy of data, extracted from related images. Much research strives to reduce the level of errors for data extraction but so far none has been able to deliver complete satisfactory and reliable result. In this research a novel approach based on thermal image analysis is presented. The new method consists of three phases: First, collecting the thermal and original images by utilizing Infrared-Camera. Second, estimating the position of captured images by the use of wireless sensor network implemented in the work space. Finally, the 3D plan will be updated automatically in the Building Information Modeling (BIM) software. The preliminary experimental results from an actual concrete building construction site show the feasibility of inferring the actual state of progress by the use of thermal images to overcome the limitation of vision monitoring.
Capacity of hybrid reinforced UHPC beams in flexure and shear
Alameer Alameer, Murat Saatcioglu
Mr. Alameer Alameer, University of Ottawa (Presenter) Dr. Murat Saatcioglu, University of Ottawa
Capacity of hybrid reinforced UHPC beams in flexure and shear
Alameer Alameer *, Husham Almansour**Â and Murat Saatcioglu*
*Graduate Student, Department of Civil Engineering, University of Ottawa, Ontario, Canada
** Associate Research Officer, Nationar Research Council Canada, Ottawa, Ontario, Canada
*Distingushed University Professor & Research Chair, Department of Civil Engineering, University of Ottawa, Ontario, Canada
(Corresponding author: Mr. A. Alameer)
Ultra-high performance fiber reinforced concrete (UHPFRC) has superior mechanical properties in addition to its superior corrosion resistance. However, the high initial cost of material prohibits widespread use and production worldwide. Optimization of structural elements that minimizes material use while maximizing their potential capacities would lead to an attractive initial cost and improve their life-cycle attractiveness. This will result in wider acceptance of the material by infrastructure owners as an efficient alternative in their future projects. Such an optimization would require the use of hybrid reinforcement, which involves steel fibers, rebars and prestressing steel tendons.
The objective of this paper is to evaluate the flexural and shear capacities of hybrid reinforced prestressed beams with the increase of the shear reinforcement (or the stirrups).
In this study, a nonlinear elasto-plastic two-dimensional finite element model (FEM) has been developed to simulate the structural behaviour up to failure. The ultimate flexural and shear strengths, as well as the resulting design are compared to the French (AFGC, 2002) and Japanese (JSCE. 2006) recommendations for simplified analysis and design. Several loading and reinforcement arrangements have been studied with detailed investigation of the stress distributions, crack patterns, stresses in prestressing tendons, and development of failure states.
Combining Expertsâ€™ Decisions and Model Tree Analysis to Select the Optimum Bridge Superstructure Type
Yassin Al-Delaimi, Elena Dragomirescu
Mr. Yassin Al-Delaimi (Presenter) Dr. Elena Dragomirescu, University of Ottawa
Selecting the most suitable bridge superstructure type forms a very sensitive and important aspect for a successful planning in bridges and infrastructure projects. Different types of criteria need to be considered and large set of data must be analyzed in the conceiving stage of bridge design. It always be essential to benefit from experts’ opinions, experiences and advices in order to reach a proper decision. As an efficient tool, the decision tree analysis is largely used to compare, evaluate and analyze different alternatives towards selecting the best scenario option. In this paper, a novel integrated optimization approach is proposed to help selecting the best design alternative. First The Client’s requirements are categorized and given an associated level of importance (IL). Each level of importance shall be given a specific weight. Secondly, the team of experts will evaluate both: i- the probable suitability of each bridge type to meet the design requirements, and ii- the probability of each bridge type to maintain the Client’s requirements. Then a decision-tree-analysis model will integrate the combined distribution of the experts’ decisions with the Client’s requirements to reveal the best scenario for the bridge superstructure type. The proposed model will also conduct a sensitivity analysis to examine how different values of independent variables will impact a specific dependent variable throughout the optimization process. The Implementation of the proposed methodology is illustrated through a case study. The results encourage bridge planners and designers to adopt the proposed model, in bridge and infrastructure projects, as a decision-making tool.
Corrections Effect on Shear Strength Parameters of Loose Sands
Tarek Omar, Abouzar Sadrekarimi
Mr. Tarek Omar, Western University (Presenter) Dr. Abouzar Sadrekarimi, Western University
Cost-Benefit Analysis of Winter Road Maintenance Standards - A Case Study
Liping Fu, Lalita Thakali, Tae J. Kwon, Taimur Usman, Michael Linton
Dr. Liping Fu, University of Waterloo (Presenter) Ms. Lalita Thakali, University of Waterloo Dr. Tae J. Kwon, University of Waterloo Dr. Taimur Usman, University of Waterloo Mr. Michael Linton, University of Waterloo
This paper describes the result of a study aiming at illustrating how models of winter road maintenance (WRM) performance measures can be applied to investigate the implications of different winter road maintenance level of service (LOS) standards under specific winter weather conditions. The study introduces a cost-benefit framework integrating the two primary cost and benefit components associated with winter road maintenance services, namely, material costs, safety and mobility benefits. Various maintenance input, output and outcome models are developed using five seasons of event-based data. The expected cost of maintaining a highway route is captured by a salt application model, which relates the amount of salt used over a snow event to various event characteristics as well as the LOS class of the highway. The benefit from WRM for a highway route is quantified on the basis of the expected safety improvements, i.e., reduction in the number of collisions, and, the expected mobility improvements, i.e., increase in trip making utility and reduction in travel time. A case study is conducted to determine the optimal traffic threshold for demarcating the Class 1 and 2 highways in Ontario. The study has demonstrated the feasibility of applying the proposed quantitative approach when assessing alternative service standards under different climate conditions.
Design of Steel Truss Cantilevered Formwork
Mohamed Darwish, Khaled Nassar, Mohamed Youssef, Mohamed Kasbar
Dr. Mohamed Darwish, The American University in Cairo Dr. Khaled Nassar, American University in Cairo Mr. Mohamed Youssef, The American University in Cairo Mr. Mohamed Kasbar, University of British Columbia (Presenter)
The architectural design of buildings with non-typical floors creates risky situations at which cantilevered slabs and beams are extended while the floor beneath has no cantilevered slabs on which the false-work could rest. The design proposed in this paper is based on using steel cantilevered trusses to support the formwork system with no need for extending the false-work along the height of the building. A closed form solution for the truss was formulated and validated using a commercial software. A parametric study was performed using the closed form solution to study the variations of the straining actions within the truss member with the truss dimensions. The study was extended in order to pick the most economic dimensions of the truss for each cantilevered truss span.
Evaluation of factors that affect budgeted cost through communication during production process in South Africa construction industry
Imisioluseyi Akinyede, Julius Fapohunda
Mr. Imisioluseyi Akinyede, Falculty of civil engineering Cape Peninsula University of Technology South Africa (Presenter) Dr. Julius Fapohunda, Department of Construction Management and Quantity Surveying Cape Peninsula University of Technology, Bellville Campus, South Africa
Evaluation of factors that affect budgeted cost through communication during production process in South Africa construction industry
Fapohunda Julius Ayodeji and Akinyede Imisioluseyi Julius, Cape Peninsula University of Technology, Bellville Campus South Africa.
Construction industry building production processes are confronted with cost restraint to deliver project at time specified and quality expected. Thus, this cost restraint predicament generates the need to evaluate the factors that affect budgeted cost through communication during production processes in South Africa. The methodology adopted for this study is quantitative method. Questionnaire survey method was employed to collect data from stakeholders in the construction industry in South Africa. SPSS software version 22 was used for quantitative data analysis. Â Findings are poor communication among construction and design team, separation of design and construction during planning and implementation stage, inadequate design details during production process, lack of coordination among stakeholders during production process and lack of team work among workers. Few of the respondents that accepted completing the questionnaire, later returned the uncompleted questionnaires and complained of too busy. The results obtained from the study reveals that efficient communication among the workers during production on site will enhance the delivery of project within budgeted cost and also augment client interest
Keywords: Budgeted cost, Client, Cost restraint, Production process, Time
Freeform-based Construction Site Layout Optimization
Ibrahim Abotaleb, Khaled Nassar, Osama Hosny
Mr. Ibrahim Abotaleb, The American University in Cairo (Presenter) Dr. Khaled Nassar, American University in Cairo Mr. Osama Hosny, AUC
Traditional approaches to the construction site layout problem have been focused mainly on rectilinear facilities where the importance proximity measures are mainly based on Cartesian distances between the centroids of the facilities. This is a fair abstraction of the problem. However, it ignores many practical and real-life aspects of the construction site layout. Firstly, the proximity importance may be based on different measures rather than a simple centroidal distance. Secondly, many facilities on the construction sites will assume non-rectilinear shapes that allow for better compaction within tight sites. The main focus of this research is to develop a practical real-life construction site layout tool that uses freeform shapes for the facilities, specifically splines, and introduces different proximity importance measures. The freeform nature of the construction site facilities allows for better compaction of these facilities in restricted sites. The new proximity importance measures take into consideration actual movement between the facilities including any passageways or access roads on the site. The problem is formulated as a genetic algorithm problem and solved using a commercial optimizer. At the end, a software tool is developed that uses a commercial parametric modeling tool (Rhino and Grasshopper) and examples are provided.Â
High Rise Building Health Monitoring
HIGH RISE BUILDING HEALTH MONITORING General Engineering Consultants
Abstract The design process of determining the optimal number of floors that may be added to an existing high rise building structure requires the thorough analysis of several important components. Various obstacles need to be considered when determining the addition of these floors. It is of high importance to evaluate how the addition of floors will affect the dead, live, wind, and seismic loading parameters of the building. Moreover, the loading capacity of the geotechnical soil properties, the existing footing, columns, shear walls, and beams in the initial design of the building need to be thoroughly analyzed. The aforementioned steps must be completed to ensure the building is as safe and economically feasible as possible. The addition of floors to an existing building design can add strain and stress to the structural components of the building and, therefore; need to be monitored. Implementing a health monitoring system in this high rise building would be very beneficial in detecting early damage to the structure. The health monitoring system will allow one to monitor, control and address any structural deficiencies before significant failure occurs. The monitoring strategy will include shrinkage, swelling, strain, deflection and creep. With the use of fiber optic sensors and external sensors, the building can be monitored to ensure that stresses and strains are recorded over the lifespan of the building. The main focus is to ensure that the building remains safe throughout its lifespan and allows owners to feel more assured in the safety of their building.
Keywords: concrete high-rise building, health monitoring, deflection, sensors
Kinematic Positioning using Online Services
Mike Mustafa Berber, Mevlut Yetkin, Aydin Ustun
Dr. Mike Mustafa Berber, California State University Fresno (Presenter) Mr. Mevlut Yetkin, Izmir Katip Celebi University Dr. Aydin Ustun
The ability of GNSS (Global Navigation Satellite System) to set points without the need for a clear line of sight between points is a valuable asset in meeting the need for placing construction reference points. In construction projects, the application of Kinematic GNSS technique has increased over the years. Nowadays, Kinematic GNSS data processing can also be done using online services. Recently, many organizations have begun providing online GNSS data processing services. Currently, some of these organizations also provide kinematic data processing option. To take advantage of this option, users only need to specify the mode of processing. Nonetheless, it seems that since there is not enough data to resolve the integer ambiguities using the engines kinematic data processing services use, the results generated by kinematic online data processing services are in the order of decimeters.
Learned Lessons from Adelaide Desalination Project
Long-Term Slip Resistance of Metallized Faying Surfaces used with High Strength Bolted Connections
Maxime Ampleman, Charles-Darwin Annan, Mario Fafard, Eric Levesque
Mr. Maxime Ampleman, Canam-Bridges (Presenter) Dr. Charles-Darwin Annan, Université Laval Dr. Mario Fafard, Université Laval Mr. Eric Levesque, Structal Bridges
Metallizing is becoming a commonly used corrosion protection solution for steel bridge members, and bridge designers need to know the slip resistance of metallized faying surfaces in order to eliminate the currently costly and time-consuming practice of masking off connection faying surfaces before metallizing. The slip resistance evaluation involves essentially two major processes; firstly, short-duration static load tests to determine the mean slip coefficient, and if the evaluated slip coefficient values are found to be satisfactory, long-term sustained tension creep tests are required to examine the effect of creep of the coating on the slip resistance. A post-creep slip test is finally carried out as part of the evaluation. Earlier tests have revealed significant slip coefficients for metallized faying surfaces beyond those specified by North American design standards for uncoated surfaces. The present study evaluates the long-term sustained tension creep performance of metallized faying surfaces used with slip-critical connections. Results of this study have indicated significant slip and creep performance, and this is likely to influence future code revisions and impact steel bridge fabrication in North America.
OBSERVATIONS OF THE WIND DAMAGE IN ANGUS, ONTARIO FOLLOWING THE JUNE EVENTS
Emilio Hong, Derek Stedman, Gregory Kopp
Mr. Emilio Hong, UWO (Presenter) Mr. Derek Stedman, UWO Dr. Gregory Kopp, UWO
The authors conducted a tornado damage investigation on June 18, 2014 in Angus, ON. The storm was reported to have occurred around 5 to 6 PM on June 17. The damage indicators support the classification of the storm as an EF-2 tornado. Most of the damage was contained within the backyards of two streets, although 101 houses were found to have sustained some level of damage, including 11 houses that sustained complete roof failure. The paper will discuss these damage observations, in light of recent wind tunnel and full-scale laboratory studies at the “3 Little Pigs” project, with the objective of defining the wind speeds associated with this tornado. The damage survey identified damage that could have been mitigated and in some cases prevented entirely. The quality of construction likely affected the performance of the roofs, with repeated patterns found in the failures. Fragility analyses of the failures, considering the effects of missing toe-nails, are included in the analysis. The results are compared from damage observations at adjacent houses, where only damage to cladding systems was observed. Additionally, there was an overturned vehicle in front of a row of houses where repeated failures occurred, providing an independent point of reference for estimating wind speeds in the tornado. Wind tunnel studies of overturning vehicles are included in this comparative analysis.
PANORAMA-BASED CHANGE DETECTION PROCESS: A PILOT STUDY ON CHALLENGES AND SOLUTIONS
Sara Rankohi, David Cody Bradley, Jeff Rankin, Lloyd Waugh
Mrs. Sara Rankohi, CANAM Building Group (Presenter) Mr. David Cody Bradley, O'Kane Consultants Inc. Fredericton, NB, Canada Dr. Jeff Rankin, UNB Dr. Lloyd Waugh, UNB
Researchers at the University of New Brunswick provide a means to document and display the progress of construction projects through panoramic images. The introduction of change detection within panoramas facilitates progress monitoring by identifying areas within the panoramas which have changed since the last capture date. This paper investigates change detection challenges and solutions to improve current panoramic change detection process. To reach this goal, a pilot study is conducted which identifies and evaluates photography and post-processing change detection variables. Adobe Photoshop is used to perform all post-processing. Areas of change within panoramas are identified using pixel based intensity differencing. The resulting change image is overlaid on the original image, highlighting changed objects and providing insight on construction progress. Change detection begins with two panoramas taken from the same location on different dates with enough time elapsed so that visible changes are evident. Research reveals that while panoramic change detection techniques produce acceptable results, they still require a significant amount of input and judgment from the user. Therefore, expanding the current status of panoramic monitoring systems through pixel based change detection is still impractical, and there is an opportunity for further research in this area.
Performance of Metakaolin Concrete
Amr El Margoushy, Khaled Saad, Mohamed Hamed, Mohamed Shaheen, Mostafa Emam, Minass Asaad, Mohamed Abou-Zeid
Mr. Amr El Margoushy, the american university in cairo Mr. Khaled Saad Mr. Mohamed Hamed, The American University in Cairo Mr. Mohamed Shaheen, The American University in Cairo Mr. Mostafa Emam, The american university in cairo Ms. Minass Asaad, The American University in Cairo Dr. Mohamed Abou-Zeid, The American University in Cairo (Presenter)
With current environmental challenges, studies have been focusing on innovative sustainable materials that can contribute to good quality concrete. Recently, there has been a growing interest in investigating the use of high-reactivity Metakaolin (MK) as a supplementary cementitious material in concrete. Metakaolin is an ultrafine pozzolanic material produced by calcinating purified kaolinite clay at temperatures ranging from 700 to 900°C and used as is incorporated as a mineral admixture.
This study focuses on studying the performance of concrete incorporating two types of Metakaolin. Thirteen mixtures were prepared using Type I and Type II Portland cement and different w/c ratios. MK was added at dosages of 10, 15 and 25% replacement of Portland cement. In addition, comparative mixtures were prepared using naturally-formed kaolin. The testing program included slump, air content, compressive strength, flexure strength, rapid chloride permeability tests as well as assessment of bonding, chemical attack and corrosion.
Results reveal that Metakaolin-modified mixtures exhibited higher workability as well as improved compressive and flexure strength tests when compared to conventional mixtures. Furthermore, both metakaolin and kaolin mixtures have demonstrated less permeability; improved bond strength and enhanced corrosion resistance. Further work is recommended to validate the findings of this study and to pinpoint other potential merits of metakaolin.
Permanent Fall-Arrest System for Low-Rise Residentials during Service Life
Falls are the reason behind one out of every five Canadian lives lost to injury-related causes every year. One of the sources of fall accidents, which is often neglected, is falling off the roof of a low-rise building after the construction is over and the structure has entered its service life. Peaked roof houses in particular pose a great falling hazard during maintenance operations due to their sloped surfaces. During the construction of such buildings, this problem is solved by using a fall-arrest system consisting of a quick-mount bracket to which a lifeline is attached, and the worker is tied to it with the lanyard connected to his/her harness. While this solves the problem during the building stage, the system is temporary and is dismantled and removed after the construction is over. The proposed solution is a fall-arrest system integrated into the structure that would be a permanent feature of the house. The design uses a galvanized steel anchor system, placed on the midspan of the peak line of the sloped roof. In order to protect it from strong winds and for aesthetic reasons, it features two hinges on its bases, thus allowing it to be bent down when not in use. The system will provide an anchor point to be used with a human fall-arrest system, while providing fall protection for ladders which might be used to access the roof. As such, it would eradicate the potential hazards from ladder slip & fall, and falling from the sloped roof.
Probability of ignition model for rupture of onshore gas transmission pipeline and its application in pipeline risk assessment
Chio Lam, Wenxing Zhou
Mr. Chio Lam, The University of Western Ontario (Presenter) Dr. Wenxing Zhou, The University of Western Ontario
An ignited rupture of a gas transmission pipeline has serious consequences in terms of human safety. The evaluation of the probability of ignition (POI) for a potential pipeline rupture is therefore critical for the risk assessment of pipelines. This paper proposes a log-logistic regression model to evaluate the probability of ignition for ruptures of onshore gas transmission pipelines. The pipeline incident data collected by the Pipeline and Hazardous Material Safety Administration (PHMSA) of the United States Department of Transportation (DOT) are utilized to develop the POI model, as a function of the pipe diameter and operating pressure. The parameters in the model are estimated using the maximum likelihood method. The proposed probability of ignition model is applied in the quantitative risk assessment of a hypothetical gas pipeline. The societal risk level associated with the hypothetical pipeline is quantified by considering the probability of rupture, probability of ignition given rupture, and population distributions in the vicinity of the pipeline. The proposed POI model will facilitate the risk assessment of onshore gas transmission pipelines.
Provide a model to select an optimum mass housing method
esmatullah noorzai, abdullah hosseini, Kobra Gharouni jafari, MohammadHossein Aghaeipoor
Mr. esmatullah noorzai, University of Tehran (Presenter) Dr. abdullah hosseini Ms. Kobra Gharouni jafari Mr. MohammadHossein Aghaeipoor
Identifying criteria affecting mass housing and comparing different construction systems with these criteria in order to determine optimal construction method based on a powerful decision making technique can considerably help to optimize mass housing, creating more incentives for private contractors and Acquiring the ultimate success in mass building projects. In this paper, most effective criteria to industry housing in three main groups of cost, time and quality were detected through interviews and questionnaires and reliability and validity of data will be discussed using SPSS software. Then alternatives of mass housing will be determined and a model will be developed using ANP technique and Super Decision software. The reason for using ANP is to organize decision-making process with respect to a scenario affected by multiple independent factors. Finally, to assess the accuracy of obtained model, the model results are compared with the actual results of the case studies. Contractors, consultants, owners and those who are concerned with the issues of industrial building are considered beneficiaries of this study.
Selection Criteria for Construction Methods of Multi-storey Underground Buildings
Mohamed Darwish, Sherifa Ismail, Zeina El Tohamy, Mohamed Shaheen, Mohamed Hamed, Hazem El Essawy, Mohamed Afifi
Dr. Mohamed Darwish, The American University in Cairo Ms. Sherifa Ismail, The American University in Cairo Ms. Zeina El Tohamy, The American University in Cairo Mr. Mohamed Shaheen, The American University in Cairo Mr. Mohamed Hamed, The American University in Cairo Mr. Hazem El Essawy, The American University in Cairo Mr. Mohamed Afifi, The American University in Cairo (Presenter)
Multi-storey underground buildings are commonly constructed for commercial or service purposes. Construction of such structures involves unique construction methods due to various characteristics like soil condition, cost, constructability, resources and time. This paper covers different methods of construction of multi-storey underground buildings and provides a comparative analysis to show when to use every method of construction according to the conditions available. Two projects in which multi-storey underground buildings were constructed with different sizes, from two different countries and with different project conditions were studied and examined against the developed selection criteria in order to evaluate the validity of the applied construction methods in each case.
Selection Criteria for Dam Construction Methods
Mohamed Darwish, Michael Thomas, Karim Wadeih, Nour Eldeeb, Mohamed Assy, Amr Eweida, Shady Wadie, Michael William, Amr Ali
Dr. Mohamed Darwish, The American University in Cairo (Presenter) Mr. Michael Thomas Mr. Karim Wadeih Ms. Nour Eldeeb Mr. Mohamed Assy Mr. Amr Eweida Mr. Shady Wadie Mr. Michael William Mr. Amr Ali
Dams are one of the very important infrastructures for countries to control and benefit from its resources. These types of projects are considered mega projects for various types of characteristics like cost, constructability, resources and time. When it comes to construction methods, there is the conventional method and innovative methods. This paper covers different construction methods covering the construction of hydraulic structures in genereal and dams in specific. The selection criteria used to determine the best method to be used for each specific construction conditions is set. Two dams with different sizes and project conditions were studied and examined against the selection criteria in order to evaluate the validity of the applied construction method in each case.
Selection Criteria for Elevated RC Tank Construction
Mohamed Darwish, Karim Kamel, Omar Balbaa, Ahmed El-feel, Jwanda Elsarag, Mohamed Tawfeek, Ahmed El-Embaby, Ghadir El-Shaer, Omar Montasser, Reem Abou Ali
Dr. Mohamed Darwish, The American University in Cairo Mr. Karim Kamel Mr. Omar Balbaa Mr. Ahmed El-feel Ms. Jwanda Elsarag Mr. Mohamed Tawfeek Mr. Ahmed El-Embaby Ms. Ghadir El-Shaer Mr. Omar Montasser Ms. Reem Abou Ali (Presenter)
Elevated tanks are necessary to supply potable water in most of the countries allover the world. Construction of elevated reinforced concrete tanks involves utilizing unique construction methods due to various characteristics like cost, constructability, resources and time. This paper covers different methods of construction of reinforced concrete elevated tanks by concentrating on different construction methods of every tank component. Moreover, a comparative analysis is provided to show when to use every method of construction according to the conditions available. Two tanks with different sizes and project conditions were studied and examined against the developed selection criteria in order to evaluate the validity of the applied construction methods in each case.
Selection Criteria for Large Caissons
Mohamed Darwish, Ramez Henen, Sarah Saleh, Marina Rostom, Omar Abdelhamid, Khaled Taha, Gasser Ali, Abdelrahman Ahmed, Hassan El Kassas, Mohamed El Ghandour
Dr. Mohamed Darwish, The American University in Cairo (Presenter) Mr. Ramez Henen Ms. Sarah Saleh Ms. Marina Rostom Mr. Omar Abdelhamid Mr. Khaled Taha Mr. Gasser Ali Mr. Abdelrahman Ahmed Mr. Hassan El Kassas Mr. Mohamed El Ghandour
Caissons are necessary for the construction of structures in complicated deep foundation conditions. Construction of caissons involves unique construction methods due to various characteristics like cost, constructability, resources and time. This paper covers different methods of construction of caissons and provides a comparative analysis to show when to use every method of construction according to the conditions available. Two projects in which caissons were constructed with different sizes, from two different construction eras and project conditions were studied and examined against the developed selection criteria in order to evaluate the validity of the applied construction methods in each case.
Selection Criteria for Long-span Bridges Construction Methods
Mohamed Darwish, Ramy Ghowiba, Mohamed Afifi, Mahmoud Elhosary, Monira Yazeed, Ahmed El Sayed, Omar Ghaly, Ahmed Elmahdy, Asmaa Mohamed
Dr. Mohamed Darwish, The American University in Cairo Mr. Ramy Ghowiba Mr. Mohamed Afifi, The American University in Cairo (Presenter) Mr. Mahmoud Elhosary Ms. Monira Yazeed Mr. Ahmed El Sayed, American University in Cairo Mr. Omar Ghaly Mr. Ahmed Elmahdy Ms. Asmaa Mohamed
Long-span bridges crossing water ways and varying topographies are necessary for transportation allover the world. Construction of such structures involves utilizing unique construction methods due to various characteristics like structural system, cost, constructability, resources and time. This paper covers different methods of long-span bridge construction by concentrating on different construction methods of every type of long-span bridges. Moreover, a comparative analysis is provided to show when to use every method of construction according to the conditions available. Two projects involving long-span bridges with different sizes and project conditions were studied and examined against the developed selection criteria in order to evaluate the validity of the applied construction methods in each case.
Selection Criteria for Short-span Bridges Construction Methods
Mohamed Darwish, Tariq Al Mahallawi, Noor Akroush, Mohamed Kasbar, Laila Amin, Noorhan Helmy
Dr. Mohamed Darwish, The American University in Cairo Mr. Tariq Al Mahallawi, American University in Cairo Ms. Noor Akroush, American University in Cairo Mr. Mohamed Kasbar, University of British Columbia (Presenter) Ms. Laila Amin, The American University in Cairo Ms. Noorhan Helmy, The American University in Cairo
Short-span bridges crossing water ways, roads and varying topographies are necessary for transportation allover the world. Construction of such structures involves utilizing unique construction methods due to various characteristics like structural system, cost, constructability, resources and time. This paper covers different methods of short-span bridge construction by concentrating on different construction methods of every type of short-span bridges. Moreover, a comparative analysis is provided to show when to use every method of construction according to the conditions available. Two projects involving short-span bridges with different sizes and project conditions were studied and examined against the developed selection criteria in order to evaluate the validity of the applied construction methods in each case.
Selection Criteria for Tunnel Construction
Mohamed Darwish, Reem Abou Ali, Osama Hashem, Shady Girgis, Menna-t-Allah Assal, Amira Youssef , Mohamed Auf, Aya Diab, Mireille Kirolos, Mohamed Seif, Yousef Shehata
Dr. Mohamed Darwish, The American University in Cairo Ms. Reem Abou Ali (Presenter) Mr. Osama Hashem Mr. Shady Girgis Ms. Menna-t-Allah Assal Ms. Amira Youssef Mr. Mohamed Auf Ms. Aya Diab Ms. Mireille Kirolos Mr. Mohamed Seif Mr. Yousef Shehata
Tunnels are necessary for transportation and sanitary purposes allover the world. Construction of tunnels involves utilizing unique construction methods due to various characteristics like cost, constructability, resources and time. This paper covers different methods of tunnel construction by concentrating on different construction methods of every type of tunnels. Moreover, a comparative analysis is provided to show when to use every method of construction according to the conditions available. Two projects involving tunnels with different sizes and project conditions were studied and examined against the developed selection criteria in order to evaluate the validity of the applied construction methods in each case.
Superstructure Replacement and Substructure Modifications to the Fort Nelson River Bridge in Northern BC
Ken Rebel, Raj Singh
Mr. Ken Rebel, McElhanney - Victoria (Presenter) Mr. Raj Singh, McElhanney Consulting Services Ltd.
The existing 8-span 430 m long single-lane Fort Nelson River Bridge on Hwy 77 was constructed in 1983 and is one of world’s longest ACROW bridges. The British Columbia Ministry of Transportation owns the bridge and because of increasing traffic demands in the region would like to replace the narrow single lane superstructure with a new two lane superstructure utilizing the existing piers and abutments.
McElhanney Consulting Services Limited has undertaken the initial foundation evaluation, condition inspection, conceptual and detailed design of the new superstructure and rehabilitation of existing abutments and piers to accommodate the heavier and wider superstructure. The existing bridge has spans of 34m – 37m – 58m – 70m – 70m – 70m – 58m – 32m with the longer spans using a double height ACROW section and the shorter spans using a single height section. The new superstructure consists of a full depth precast concrete composite deck with an out to out width of 10.0 metres and three continuous lines of steel girders that vary in depth from 1.1 metres to 3.3 metres. The girders have been designed to be launched into place from the north end of the bridge. The abutments require additional piles and modified seats and backwalls to accommodate the wider structure. The land piers also require new steel pipe piles cast into new wider pile caps that support the existing pier shafts. As the bridge is to be constructed in the extreme north, a significant amount of the structure is to be fabricated off-site and assembled on site.
Team Gushue Highway extension using Techspan Concrete arch for river crossing.
Thomas Brunet, Bill Demers
Mr. Thomas Brunet, Reinforced Earth Company Ltd. (Presenter) Mr. Bill Demers, Reinforced Earth Company Ltd.
~Team Gushue Highway Extension St. Johnâ€™s NL This paper will outline the Newfoundland and Labrador Ministry of Transportation and Works project, of a TechSpan concrete arch culvert, constructed over the Waterford River to support a 19 m high embankment for the Team Gushue Highway Extension. Named in honor the 2006 Olympic Gold medalist curling team, The Team Gushue highway once completed will provide a vital link to the NW Avalon Peninsula. The highway is designed to relieve traffic congestion on all major routes in the region, and when finished, will connect the Outer Ring Road in the north with Robert E. Howlett Memorial Drive to the south. The Waterford river crossing was a major technical and construction challenge on this project. The 10 m wide river runs in a 19 m deep meandering gorge and has a swift current, making work in and around the river challenging. Access to the site was extremely difficult. Two very steep grade construction roads on each side of the river connected by a temporary bridge provided access to the bottom of the gorge and the erection site. A temporary diversion of the river permitted for excavation and site casting of two 5.35 m wide footings and the erection of the concrete arch culvert in the dry. The 63m long, 11m span, 4m high concrete arch structure supports 19 m of overburden and the highway road base, allowing the highway a level crossing of the gorge and river. This paper highlights the purpose of this significant new work, the creek sensitivity and diversion, and the design and construction of an arch structure supporting hydraulics and very high overburden. Also reviewed are the construction costs and schedule, and the long term maintenance compared to a bridge deck.
User-Updatable Municipal Benchmark Database for the City of Regina
Nathan Bruce, Kelvin T. W. Ng
Mr. Nathan Bruce, University of Regina (Presenter) Dr. Kelvin T. W. Ng, University of Regina
The purpose of this project is to develop a means to provide the status of municipal benchmarks for surveying purposes in the City of Regina. Currently, benchmark data is sent out whenever significant updates or changes are made. Typically, updated books are released annually in Regina, although the descriptions usually do not account for recent developments, thus providing misleading directions to surveyors.Â The latest update quotes that 3.3% of the benchmarks have been destroyed during structural, civil, and roadway projects, but the unreported percentage is unknown. The database would contain the standard information found in benchmark data sets, photographs of found benchmarks, and possible reasons for absent benchmarks. Three alternatives for data collection exist: (i) a single team searches and collects the data; (ii) the team requests the status of benchmarks from public and private surveyors from past projects; (iii) or a combination of the first two approaches. Data collection would continue after the database is released, and users would be asked to flag outdated data. The database could take the form of a mobile application for real-time use, and/or a file available on the City's website. This project can reduce preliminary surveying time by up to 50% upon completion of data collection.
Using Earth Materials and Simple Techniques for Low Cost Housing
Mireille Kirolos, Abd El Raouf Hassan, Asmaa Mohamed, Hazem El Essawy, Amira El Sherbiny, Minass Asaad, Mohamed Abou-Zeid
Ms. Mireille Kirolos (Presenter) Mr. Abd El Raouf Hassan, American University in Cairo Ms. Asmaa Mohamed Mr. Hazem El Essawy, The American University in Cairo Ms. Amira El Sherbiny, The American University In Cairo Ms. Minass Asaad, The American University in Cairo Dr. Mohamed Abou-Zeid, The American University in Cairo
Half of Cairo’s 17 million inhabitants live in informal areas at densities of up to 60,000 people per km2. The catch-all label of informal areas has recently been subdivided by government into ‘Unsafe Areas’ in which people’s lives and health are at risk
As a result of the neglect and poverty that they are living in they live in inhumane housing conditions. These materials deteriorate, offer no shelter and have negative effect on their health by time.Earth construction is divided into many techniques and categories its strength is not as high as other bricks but it has lower cost and simpler structural systems.
The scope of research in this paper is to create a system of housing that is healthier, environmental, economical and architectural to replace the inhumane practices and areas that are present now in Egypt. The paper involves recorded results and mechanical characteristics of earth construction (earth bags). The stabilized earth will be divided into different types of soils and using different stabilizers to reach allowable and reasonable strength with the lowest cost and available materials.
The materials used are environmentally friendly and available at hand; the excavated soil, whatever type it is, will be used, along with cement or lime. Many tests are done on the bricks and the soils like sieve analysis, compaction, atter berg limits, hydrometer, compressive strength, absorption test and compression test on a small wall. To demonstrate and compare different systems a small model will be constructed on the university campus.
Value Engineering Applications to Improve Value in Residential Projects
Racha Rachwan, Ibrahim Abotaleb, Mohamed Abdelghany, Amr Fathy, Ahmed AlBughdadi
Mrs. Racha Rachwan, ACE Project Management Mr. Ibrahim Abotaleb, The American University in Cairo Dr. Mohamed Abdelghany, ACE Project Management Mr. Amr Fathy, The American University in Cairo (Presenter) Mr. Ahmed AlBughdadi, The American University in Cairo
A PARAMETRIC STUDY ON TEMPERATURE AND SHRINAKGE CRACKING IN REINFORCED CONCRETE TANK WALLS
Dylan Matin, M. Reza Kianoush
Mr. Dylan Matin, Ryerson University (Presenter) Dr. M. Reza Kianoush, Ryerson University
The design criteria in reinforced concrete tank walls subjected to temperature and shrinkage effects are important due to problems associated with cracking and leakage. There are major debates and disagreement on the amount of minimum reinforcement proposed in current codes and standards for this purpose. The current design guides are based mainly on engineering judgment and past performance of these structures. In this study, the cracking behavior of reinforced concrete (RC) tank walls subjected to temperature and moisture variations is evaluated using the finite element (FE) method. Three-dimensional shell elements are used to discretize the tank walls with reinforcement layers defined as smeared layers. The non-linearity of concrete is defined using the brittle cracking constitutive model. The FE model is verified by comparing the crack width and crack pattern of a previous experimental study. The influence of reinforcement behaviour (linear vs non-linear) on crack width is discussed. Cracking behavior of single walls is compared with 3D full tank models. It is shown that taking the steel nonlinearity into account could have a considerable effect on crack width. Simulating the entire tank as opposed to a single wall show some differences on the crack width and pattern. The influence of tank wall dimensions, reinforcement ratio, climate and concrete strength is demonstrated on the width of developed cracks. Design recommendations are provided proposing the minimum amount of reinforcement ratio required to control shrinkage and temperature cracking in RC tank walls.Â
An experimental Investigation on the Strength and Durability of Self-healing Bacterial Concrete
SINI BHASKAR, Mohamed Lachemi, Khandaker Hossain, Gideon Wolfaardt, Marthinus Kroukamp
Mrs. SINI BHASKAR, Ryerson University (Presenter) Mr. Mohamed Lachemi, Dr. Khandaker Hossain, Ryerson University Dr. Gideon Wolfaardt, Ryerson University Dr. Marthinus Kroukamp, Ryerson University
Crack repair in concrete is crucial since cracks are the main cause of the decreased service life of concrete structures. An original and promising way to repair cracks is to pre-incorporate healing agents inside the concrete matrix to heal cracks the moment they appear. By incorporating bacteria and nutrients as a two component healing agent in concrete matrix, the process of bacterially mediated calcium carbonate deposition was triggered upon crack formation and self-healing of cracks can be expected. This research is aimed at investigating the potential of different mineral producing bacteria on their long-term viability, their incorporation in the concrete matrix and their self healing ability for autonomous crack repair. Two different types of bacteria are used to find out the best possible among them. Two different carrier materials are used in this study to protect bacteria from the high-pH environment of concrete. In order to develop a self-healing bacterial concrete, it is crucial to understand how the introduction of the mineral producing bacteria and affect of nutrients on the properties of concrete, giving emphasis on closure of cracks. The long term durability of concrete is affected to a large extend by its permeability. Hence, the permeation properties are the important factors to study in relation to concrete durability. Therefore, this paper presents the results of an experimental investigation carried out to evaluate the influence of bacteria on compressive strength and permeation properties.
Comparing Lab and Field Data of Concrete Affected by Alkali-Silica Reaction and Freeze-Thaw Deterioration
Matthew Piersanti, Medhat Shehata, Stephen Senior, Carole Anne MacDonald
Mr. Matthew Piersanti, Ryerson University (Presenter) Dr. Medhat Shehata, Ryerson University Mr. Stephen Senior Ms. Carole Anne MacDonald, Ministry of Transportation
In Canada there are a wide variety of environmental conditions, which aid in the deterioration of concrete. A number of accelerated lab tests have been created and modified over the years to stimulate a specific deterioration mechanism in order to accurately predict how different concrete mixes will react in a given environment. Although these tests provide data over a short period of time, the data obtained in the field is a more accurate measure of total deterioration due to multiple mechanisms working simultaneously, such as freeze-thaw deterioration and alkali-silica reaction (ASR). This is because conditions in the lab provide accurate results for a single deterioration mechanism, however in reality, multiple mechanisms are contributing to the deterioration simultaneously. The research presented in this paper compares lab and field expansion results, specifically ASR and freeze-thaw deterioration. Field measurements of expansion of concrete road barriers were taken and classified into two categories – high and low deteriorated. In the lab, expansion tests for ASR are being completed on samples that have been cast with the same natural coarse aggregate used in those road barriers along with recycled concrete collected from both high and low deteriorated road barriers. Cores that were extracted from the same barriers are also undergoing lab testing for ASR. In order to closely predict the deterioration mechanisms occurring in the road barriers, the expansion data obtained from the lab and field were compared. Thus, a prediction can be made about the contribution of additional mechanisms on the deterioration of the barriers.
DEVELOPMENT OF ULTRA HIGH PERFORMANCE CONCRETE AS A CLOSURE STRIP MATERIAL IN PREFABRICATED BRIDGE APPLICATIONS
Mohtady Sherif, Mahmoud Sayed Ahmed, Khaled Sennah, Philip Zacarias, Salih Judieh
Mr. Mohtady Sherif, Ryerson University (Presenter) Dr. Mahmoud Sayed Ahmed, Ryerson University Dr. Khaled Sennah, Ryerson University Mr. Philip Zacarias, St. Marys / Canada Building Materials Mr. Salih Judieh, Ryerson University
There is a growing need for durable and resilient prefabricated bridge systems which facilitate rapid completion of on-site activities in order to minimize the impact on the travelling public. Prefabricated bridges can provide higher quality, accelerated, and safer construction; however, greater offsite prefabrications of bridge components necessitates an increased reliance on the long-term performance of field-installed connections between these components. Of particular interest here, UHPCs can exhibit exceptional bond when cast against previously cast concrete and can significantly shorten the development length of embedded discrete GFRP bars. With the recent innovations in bridge infrastructure replacement and construction using “accelerated bridge construction technologies”, the use of UHPC in closure strips between precast concrete segments in fabricated bridges construction became the main focus of bridge owners for its superior strength and durability. To increase competitiveness in supplying UHPC to bridge owners in Canada, this collaborative research with the industry is looking into an innovative UHPC design that combines both high concrete compressive strength, and enhanced durability and rheology. It is essential to produce design standards and performance-based specifications of UHPC through experimental trial and errors due to lack of reliable information in this subject in the related standards and literature. This research investigates different mixes designed to reach the desired strength and rheology. While UHPC materials clearly outperform conventional concrete in mechanical and durability performance, their production is proprietary and the development of economically competitive alternatives is warranted. This paper summarizes phase I of this research project to develop UHPC mix with target rheology and compressive strength characteristics. Throughout this phase, the desired fresh and hardened concrete properties as well as practical mixing procedure were achieved and reported herein.
Effect of Steel Fibers on Flexural Response of Recycled Concrete Material
Sadegh Kazemi, Hasan Jalilifar
Dr. Sadegh Kazemi, WSP (Presenter) Mr. Hasan Jalilifar
This research study reports on the experimental tests conducted to establish the influence of randomly distributed double-hooked steel fibers on mechanical properties of the recycled coarse aggregate concrete (RCA-C)in compression and flexure. The RCA-C formulated with 50% recycled aggregate replacement and 0 to 1.5% steel fiber volume-fraction was examined. A series of compressive test on cube samples along with three-point flexural tests of notched prism specimens were completed. The peak compressive and flexural strength was found to increase as the fiber volume fraction increased. The measured experimental test results were further analyzed to evaluate the effect of fiber volume fraction on the compressive and flexural toughness. Considerable improvements in the toughness were obtained for mixes with higher fiber content.
Interaction of Superabsorbent Polymers and Admixtures on the Properties of Engineered Cementitious Composites
Mohamed Sherir, Khandaker Hossain, Mohamed Lachemi
Mr. Mohamed Sherir (Presenter) Dr. Khandaker Hossain, Ryerson University Mr. Mohamed Lachemi,
M.A.A. Sherir, K.M.A. Hossain and M. Lachemi Department of Civil Engineering, Ryerson University, Toronto, Ontario, Canada
ABSTRACT: The addition of Superabsorbent Polymers (SAP) as additives can strongly affect the mechanical characteristics and enhance the water content for internal curing of Engineered Cementitious Composite (ECC). ECC is a special type of ductile concrete with high tensile strain hardening and micro-cracking characteristics due to the presence of Polyvinyl Alcohol Fibers (PVA). This paper presents the results of a research conducted to investigate the effect of different types and sizes of SAP’s and different chemical admixtures on the fresh and mechanical properties of ECC mixtures when both W/C ratio and dosages of superplasticizers are adjusted. Different mixing procedures are also produced to get the optimum self-consolidating characteristics of ECC’s when mixed with SAP’s. In addition, high volume of Supplementary Cementing Materials (SCMs) is used in this research in order to produce sustainable, greener and cost-effective ECC concrete for construction applications.
Seismic Strengthening of Reinforced Concrete Squat Walls Using Externally Bonded CFRP Sheets
Joshua Woods, Carlos Cruz-Noguez, David Lau, VICTOR REYES
Mr. Joshua Woods, Carleton University (Presenter) Mr. Carlos Cruz-Noguez, University of Alberta Mr. David Lau, Carleton University Mr. VICTOR REYES, FYFE CO LLC
Despite significant advances in earthquake resistant design of reinforced concrete (RC) structures over the past two decades, there is still a large stock of existing shear wall structures designed and constructed using older less stringent design standards. Evidence from past earthquakes has shown these structures pose a significant risk to the life-safety of its occupants due to inadequacies in their design. Common structural deficiencies in their design include poor confinement of boundary elements and insufficient shear reinforcement. These deficiencies contribute to poor seismic performance characterized by a lack of strength, ductility and energy dissipation capacity. With the goal of improving the seismic behaviour of deficient RC shear walls, this paper presents experimental results on a minimally disruptive retrofitting scheme consisting of externally bonded fibre-reinforced polymer (FRP) sheets. The test specimens are 2/3 scale RC squat walls with a height-to-length aspect ratio of 0.85 tested to failure under reversed cyclic lateral load. The wall specimens are detailed with the structural deficiencies commonly found in walls designed according to older design standards. The wall specimens are retrofitted using a combination of vertical and horizontal FRP sheets applied to a single side of the wall, designed to eliminate premature shear failure and enhance the flexural load carrying capacity. Results on two different anchor systems are presented including FRP anchors, and a new tube anchor system developed at Carleton University. Results demonstrate the ability of using FRP as a viable retrofitting alternative to improve the seismic performance of deficient RC squat walls.Â
Size Effect on the Shear Strength of High-Strength Concrete Continuous Beams Reinforced with GFRP Bars
Karam Mahmoud, Ehab El-Salakawy
Dr. Karam Mahmoud, University of Manitoba (Presenter) Dr. Ehab El-Salakawy, University of Manitoba
~~The use of the non-corrodible fiber reinforced polymer (FRP) bars as main reinforcement for concrete structures to overcome the steel corrosion problem is exponentially increasing. The FRP bars, as longitudinal reinforcement, made the size effect on shear strength more pronounced than that in steel-RC beams. This effect was more significant in beams made of high strength concrete and with small longitudinal reinforcement ratio. This study evaluates the size effect on shear capacity of continuous high-strength concrete beams reinforced with glass (G) FRP bars. The experimental results of six large-scale continuous concrete beams are presented. The test beams had a rectangular cross section of 200 mm width and three different effective depths of 250, 500 and 750 mm. The beams were continuously supported over two equal spans of 2,800, 3,750 and 5,250 mm for beams with depth of 250, 500 and 750 mm, respectively. The test variables were the effective depth of the beam and the longitudinal reinforcement ratio. The test results showed that significant size effect was observed with increasing the effective depth in beams failed in the exterior shear span. The opposite was observed in beams failed in the interior shear span where the shear strength increased when the depth increased. Test results also were compared to the predictions of shear design provisions in the CSA/S806-12 standard and the ACI 440.1R-06 guidelines.Â
Stress-Strain Behavior Model of FRP-Confined Concrete: A State of the art Review
Fiber reinforced polymer (FRP) composites are often used to confine concrete, for seismic strengthening of existing reinforced concrete (RC) columns and for concrete filled FRPs tubes as earthquake-resistant columns in new structures. For the safety and serviceability of these structural elements, it is essential to understand the behavior at the element level. This is often done by observing the stress-strain behavior of FRP-confined concrete. In the past two decades, several researchers conducted extensive experimental and analytical investigations to understand and predict the stress-strain behavior of FRP-confined concrete under axial compression. This paper presents an extensive review of the previously published literature on the stress-strain behavior of FRP-confined concrete in circular concrete sections. The reviewed models will be categorized into two broad groups, such as design orientated models (DOMs) and analysis oriented models (AOMs). In the final part of the paper, a critical discussion is presented by comparing the constitutive models with the experimental results. The essential factors that influence the overall performance of the models are also highlighted.Â
Surface Reinforced Concrete Masonry Units: An Introduction to the Future of Concrete Masonry Construction
Adrien Sparling, F. Hashemian, Myron Britton
Mr. Adrien Sparling (Presenter) Dr. F. Hashemian, University of Manitoba Mr. Myron Britton, University of Manitoba
Conventional concrete masonry assemblies using hollow Concrete Masonry Units (CMU) are reinforced by bonding reinforcing bars within the cores using masonry grout. This locates the reinforcing bars at or near the masonry systemâ€™s out-of-plane neutral axis. The innovative Surface Reinforced Concrete Masonry Unit (SRCMU) uses vertical channels in its external faces to allow near-surface-mounting (NSM) of reinforcement. This hollow concrete masonry construction method allows greater flexural strength to be achieved while reducing the over-all weight of the concrete masonry assembly by 50% due to the elimination of grout filling of the cores. This fosters significant construction cost savings and reduced environmental impact. A comparison of masonry systems utilizing the SRCMU with NSM reinforcement and conventional hollow concrete masonry systems was performed using the CSA S-304 for out-of-plane loading conditions. Under conditions of combined axial and out-of-plane flexural loading, the SRCMU masonry systems had an increased flexural capacity of up to 30% over the conventional concrete masonry systems with the same reinforcement ratio and effective cross sectional area. Numerical modelling and physical testing of unreinforced conventional masonry prisms and SRCMU prisms showed that they have similar behaviour and modes of failure under axial loading conditions. SRCMU flexural specimens reinforced using epoxy-grouted reinforcing bars were tested under 4-point bending. Steel reinforced specimens achieved an average resistance that matched the prediction from the CSA S-304 analysis; this demonstrates SRCMU systems can achieve greater load carrying capacities with less material while maintaining modes of failure and design characteristics similar to conventional CMU construction.
The effect of circumferential flaws on the strain capacity of pressurized X52 pipelines
Diana Abdulhameed, Celal Cakiroglu, Millan Sen, John Nychka, Jung-June Roger Cheng, Samer Adeeb
Ms. Diana Abdulhameed, University of Alberta (Presenter) Mr. Celal Cakiroglu, University of Alberta Mr. Millan Sen, Enbridge Pipelines Dr. John Nychka, University of Alberta Dr. Jung-June Roger Cheng, University of Alberta Dr. Samer Adeeb, University of Alberta
Tensile strain capacity (TSC) of pipelines with girth weld flaws have been traditionally measured experimentally using wide plate tests. However, Numerical analysis in recent studies showed that the TSC are affected by the level of internal pressure inside the pipeline, Y.Wang (2008). Most of the past studies focused on the effect of circumferential flaws on the TSC for pipelines of steel grade X65 or higher. The current Oil and Gas Pipeline System Code CSA Z662-11 provide equations to predict the critical TSC as a function of geometry and material properties of the pipelines. These equations were based on extensive studies on pipes having grades X65 or higher without considering the effect of internal pressure which makes it beneficial to be investigated. In this study, eight full-scale experimental tests of NPS 12" pipes with 6.91 mm wall thickness and grade X52 were conducted in order to investigate the effect of circumferential flaws close to a girth weld on the TSC for vintage pipelines subjected to eccentric tensile forces and internal pressure. A digital image correlation system and biaxial strain gauges were used to obtain the tensile strain along the pipe length during the test. Post-failure macro-fractography analysis was used to confirm the original size of the machined flaw and to identify areas of plastic deformation and brittle/ductile fracture surfaces. From the experimental and numerical results, the effect of internal pressure and flaw size on the TSC was investigated. The CMOD at failure for different pipes were compared.
A province-wide comparison of non-hazardous waste generation and recycling rates
Nathan Bruce, Yu Wang, Kelvin T. W. Ng
Mr. Nathan Bruce, University of Regina (Presenter) Ms. Yu Wang, University of Regina Dr. Kelvin T. W. Ng, University of Regina
This paper presents a comparison of non-hazardous waste generation and diversion programs between Manitoba (MB) and Saskatchewan (SK) in Canada. Residential and non-residential waste data was compiled from Statistics Canada's waste reports covering biennial years between 1998 and 2010. SK and MB were selected due to their similarities in population, location, and climate. Studies in developing countries show that increased economic growth and population increases waste generation. Population has risen in the Prairie Provinces by 49% within the last 30 years, increasing the need for diversion programs. SK generated 15% more non-residential waste than MB on average, while MB's average residential waste generation was 17.5% higher than SK's. SK and MB's diversion rates were lower than the national average during the study period. Neither SK nor MB operated a publicly-funded curb-side recycling program during the study period, though major cities in both provinces have since implemented these programs. Centralized composting, electronic waste, and various recycling depot programs were implemented in SK and MB during the study period. Combining pay-as-you-throw waste programs with a recycling program has reduced waste disposal in some US communities by 25-45%, which may help increase diversion rates in SK and MB.Â
An Assessment of the Waste Diversion Programs in Ontario, Canada
Rajesh Shrestha , Kelvin T. W. Ng, Asma Chowdhury
Mr. Rajesh Shrestha , University of Regina Dr. Kelvin T. W. Ng, University of Regina Ms. Asma Chowdhury, University of Regina (Presenter)
The purpose of this study is to examine and evaluate various waste diversion programs in Ontario during the period between 1996 and 2010. Waste diversion is a very important component in modern solid waste management, and its objective is to minimize the amount of landfill disposal. A literature review suggested that municipal solid waste management in Ontario is complex, and a multidisciplinary approach is needed. Waste management teams are required to understand the sources and generation of wastes, waste characteristics, risk management, emerging technologies, laws and regulations, waste trends, and economic aspects of waste.
In this study, Statistics Canada waste data were collected for the period from 1996 to 2010. Although Ontario started waste diversion programs in the 1980s, data during the earlier periods were not readily available. It was found that Ontario had made significant progress in waste diversion until 2008, when the volume of diverted waste started to decline. For instance, Ontario generated over 9 million tonnes of solid waste in 2010, but only 2.7 million tonnes (or 29.7%) were diverted. The results suggested that Ontario should review its current waste diversion programs and develop new waste management frameworks. The new approach should include the following concepts: implementation of 3Rs, producer-based approach, product development and packaging protocols, and development of specific waste management techniques based on materials or locations.
Application of Rhamnolipid and Microbial Activities for Improving the Sedimentation of Oil Sand Tailings
Catherine Mulligan, Soroor Javan Roshtkhari
Dr. Catherine Mulligan, Concordia University (Presenter) Ms. Soroor Javan Roshtkhari , Concordia University
~~Densification of oil sand tailings deposited in the tailing ponds and water recovery are two major challenges issues in the oil sands industry. A small increase in the tailing settlement rate can improve tailingâ€™s densification and significantly reduce water consumption and the volume of tailing ponds. Currently most industrial consolidation methods are based on clay particle flocculation using gypsum and polymeric flocculants. In this work, the potential of rhamnolipid as a flocculating agent and microbial activity for increasing the sedimentation rate of fine tailings was investigated. Sedimentation increased by increasing the rhamnolipid concentrations. According to the result of zeta potential and particle size distribution, rhamnolipid has increased sedimentation by improving the hydrophobicity of particles. Different concentrations of rhamnolipid with the two microbial strains isolated from weathered oil led to an increase in sedimentation (by a maximum factor of 3.04), the concentration of larger particles (by a maximum factor of 1.9), particle mean diameter (by a maximum factor of 2.11) and flocculation significantly. This could be probably due to the interaction of biosurfactant and high molecular weight organics with clay particles (through a bridging mechanism, and improving hydrophobicity) or due to the change in chemistry of pore water as a result of microbial metabolism. This work shows the potential of using rhamnolipid and microbial culture for increasing the oil sand tailing sedimentation in a potentially more environmental friendly and economical process. Further research is needed to determine the biosurfactant fate in the recycled water and the microbial role in sedimentation.
Brewery Wastewater Treatment by Anaerobic Membrane Bioreactor
Richard Chen, Sheng Chang, Youngseck Hong, Ping Wu
Mr. Richard Chen, University of Guelph (Presenter) Dr. Sheng Chang, University of Guelph Mr. Youngseck Hong, GE Water and Process Technologies Mr. Ping Wu, Ontario Ministry of Agriculture, Food and Rural Affairs
The micro-brewery business has been subjected to rapid growth within the last decade. Most brewers are facing expensive wastewater compliance bills and are seeking reliable on-site treatment methods. Anaerobic membrane bioreactor (AnMBR) treatment is favorable to the widely used upflow anaerobic sludge blanket (UASB) method. It offers high quality effluent with free of solids, and has a great stability under loading shocks. To date, there have been limited submerged AnMBR studies and none have been conducted on brewery wastewater. In this research, a state-of-the-art AnMBR laboratory scale system (supplied by GE Water and Process Technologies) was used to investigate the performance and capability. The system was subjected to 230 days continuous operation with both synthetic and real brewery wastewater at organic loading rates (OLRs) ranging from 2 to 11.5 kg COD/m3/day. During all tested OLRs, the AnMBR system demonstrated an excellent COD removal efficiency (>98%) and produced high quality effluent with less than 300 mg/L COD, as well as maintained a stable methane yield at 0.31 m3 CH4/kg COD (35 0C). While the system demonstrated an excellent biological performance, the study found that the major limitation of AnMBR was the membrane fouling, which increased with the OLR and soluble microbial products (SMPs) in the mixed liquor. The study suggests that AnMBRs should be operated at an OLR below 6.5 kg COD/m3/day and a filtration flux of 7 L/m2/hour (LMH) to achieve long term stability for treatment of high organic strength brewery wastewater treatment.
Comparison of the Costs and GHG emissions of Different Treatment methods for CTMP Pulp and Paper Wastewater
NAJMEH ABEDI, Catherine Mulligan, Laleh Yerushalmi
Mrs. NAJMEH ABEDI (Presenter) Dr. Catherine Mulligan, Concordia University Dr. Laleh Yerushalmi, Concordia University
The atmospheric concentration of carbon dioxide which constitutes the major greenhouse gas (GHG) has increased significantly after the industrial revolution. Many attempts have been made aiming at the reduction of CO2 in the atmosphere. In the present study, a hybrid treatment process is developed for CO2 removal from wastewaters generated by industrial operations. In the developed process, a CO2-saturated wastewater enters an anaerobic reactor where CO2 is bioconverted to methane, followed by an aerobic reactor for additional treatment of the wastewater. This study evaluates the economic feasibility of the developed hybrid treatment process to treat CTMP wastewater from the pulp and paper industry, making a comparison of this process with the aerobic and conventional hybrid (anaerobic/aerobic) treatment systems. The GoldSetTM software is applied to compare various treatment methods based on their corresponding economical, environmental and social aspects. The anaerobic and aerobic treatment systems in the present case study use IC (internal circulating) and activated sludge processes, respectively. The results show the advantages of the developed hybrid treatment process compared to the conventional hybrid and aerobic treatment methods.Â
Degradation of Bisphenol A using advanced oxidation processes
Mitra Mehrabani-Zeinabad, Gopal Achari, Cooper H. Langford
Ms. Mitra Mehrabani-Zeinabad, University of Calgary Dr. Gopal Achari, University of Calgary (Presenter) Dr. Cooper H. Langford, University of Calgary
Emerging contaminants (EC) are a group of contaminants comprising of pharmaceuticals and personal care products, various industrial additives, pesticides and others that are increasingly found in water bodies. A common EC often detected in water bodies is Bisphenol A (BPA). BPA is used for production of polycarbonate and epoxy resins, unsaturated polyester-styrene resins and flame retardants. The final products are used as can coatings, additives in thermal paper, dental fillings and antioxidants in plastics used in food and drink packaging. A major source of release of this compound into the environment is through Waste Water Treatment Plant (WWTP) effluents. A high percentage of this compound passes through biological treatment processes, since it is highly stable and enters the aquatic environment. BPA has been detected at WWTP influents ranging from 0.08-4.98 µg/L and in effluents from 0.01-1.08 µg/L. This paper presents degradation of BPA using various advanced oxidative processes including UVC, UVC/H2O2 and O3.Reaction kinetics were obtained and effective parameters of each process in spiked water and wastewater were identified and optimized. The effect of inorganic ions and organic matter present in secondary treated wastewater on the degradation rate was also investigated. The results showed the best process for degrading BPA was with O3.The highest degradation rate at optimized conditions for water was with 1 L/min O3 which had a k-value of 1.196 min-1 with complete removal in 3 minutes and in wastewater was with 4 L/min O3 which had a k-value of 1.750 min-1 with complete removal in 2 minutes.
Descriptive Statistical Analysis on Paper, Plastic, and Glass Recycling in Ontario, Canada
Asma Chowdhury, Kelvin T. W. Ng
Ms. Asma Chowdhury, University of Regina (Presenter) Dr. Kelvin T. W. Ng, University of Regina
Ontario's municipal solid waste generation and disposal rates increased noticeably from 1996 to 2010, partly due to the 16% increase in population. The province has adopted a number of waste management initiatives and programs to divert non-hazardous wastes from landfills and other disposal facilities. The key objective of this study was to statistically analyze the recycling trends of paper, plastic, and glass wastes in Ontario. A detailed assessment program was developed in this study. Waste management programs from Waste Diversion Ontario and the Recycling Council of Ontario during the study period were investigated and discussed. Waste recycling data was collected from Statistics Canada, and verified from other literature. Descriptive statistical analyses were performed to examine the temporal variability of the waste recycling behaviors and practices. Regression analyses and Mann-Kendall (MK) tests were conducted to quantify the waste recycling trends. It was found that the waste recycling rates have increased significantly during the study period. For example, roughly 85% increases were observed for both paper and glass recycling. The trend analysis also showed significant increasing trends for all three waste materials. Plastic wastes exhibited the strongest trends with the highest MK statistic value (S = +26), and a 99% level of significance. The recycling trends of paper and plastic materials were found to be significant at 80% and 90% level of significance with S values of +8 and +12, respectively.
Design Principles and Regulatory Requirements of MSW Landfill Gas Management System in Western Canada
Meherun Nesha, Kelvin T. W. Ng
Mrs. Meherun Nesha, University of Regina (Presenter) Dr. Kelvin T. W. Ng, University of Regina
Landfill gas management systems reduce methane gas emissions, carbon footprints, and fire/explosion hazards on the landfill property and adjacent areas. This paper discussed the design methods and regulatory framework for landfill gas management systems in British Columbia, Alberta, and Saskatchewan. The purpose of this study was to examine the design standards and approaches, and to compare the legislative regulations associated with the design and operation of landfill gas management systems.
The results of a literature review suggested that the design principles and regulations are wildly different between the provinces. Both British Columbia and Alberta have adopted regulations for landfill gas management. A gas monitoring program, and methane gas migration control measures are required in British Columbia. Such facilities must be approved by the respective regulatory agencies. Methane concentration is limited to: 12,500 ppm (25% Lower Explosive Limit) in any on-site or off-site building; and 50,000 ppm (100% Lower Explosive Limit) at the property boundary. Similarly, a subsurface landfill gas contingency plan is required at Alberta landfills. Lateral migration of methane gas at landfill sites is common due to the properties of local geological materials. The subsurface landfill gas explosive limit is 50% within the property, 20% in an on-site building, and 1% in an off-site building. Saskatchewan adopted a new environmental code (SEC) at the end of 2014. The results-based approach to environmental regulation was used throughout the new SEC. Gas monitoring devices and migration control systems are both required, but specifications on the methane concentrations or explosive limits are not
Evaluation of using Recycled Glass as Concrete Aggregate - ASR Test Results
Abdurahman Lotfy, Solomon Asantey, Amneh Kalloush
Dr. Abdurahman Lotfy, Lafarge Canada Inc. Dr. Solomon Asantey, Fanshawe College (Presenter) Ms. Amneh Kalloush, Fanshawe College
To strive for more sustainability contribution, the use of recycled glass as aggregate in concrete has attracted much research interest. Many studies have been performed by mixing different sizes and percentages of glass to replace aggregate in concrete mixes. Test results have shown that concrete containing glass as an aggregate replacement has lower water absorption. However, the use of glass in concrete may result in alkali-silica reaction (ASR). This reaction causes extensive cracking and expansion within the aggregate particles, resulting in potential durability issues of hardened concrete. The objective of this research was to investigate the potential for alkali reactivity of concrete aggregates when using mixes containing different percentages of local recycled crushed glass. During the summer of 2014, trial tests were conducted by Lafarge Canada Inc. and Fanshawe College’s Concrete Technology Research Group to assess the use of recycled glass as an aggregate in concrete. This paper presents the results of ASR testing on several mixes using different percentages of glass. The tests were completed based on the requirements of ASTMC1260–Standard Test Method for Potential Alkali Reactivity of Aggregates (Mortar-Bar Method). The expansion of the prepared test specimens increased as the replacement level of glass aggregate increased. The results demonstrate that even as low as 5% replacement of recycled glass as fine aggregate in concrete, the percentage expansion was excessive leading to considerable durability issues.
AbdurahmanLotfy, Ph.D., P.Eng.
Regional Manager, New Products Development, Innovation & Commercialization, Lafarge, Toronto, ON
Solomon Asantey, Ph.D., P.Eng.
Professor, Civil Engineering Technology Program,
Principal Investigator, Concrete Technology Research, Fanshawe College, London ON
Professor, Civil Engineering Technology Program,
Co- Investigator, Concrete Technology Research, Fanshawe College, London ON
Life cycle assessment to compare different types of 'green' concrete
Karina Seto, Cameron Churchill, Daman Panesar
Ms. Karina Seto, University of Toronto (Presenter) Mr. Cameron Churchill, McMaster University Dr. Daman Panesar, University of Toronto
Over the past two decades efforts have been made to ‘green’ the concrete industry; from material selection and manufacturing to the implementation of innovative concrete products. A variety of concrete mix designs are considered to be ‘green’ and are often referred to as ‘sustainable’ such as concrete containing supplementary cementing materials, photocatalytic concrete, pervious concrete, recycled aggregate concrete, etc.. These sustainable cement-based materials can potentially reduce the environmental impact of concrete applications over various stages of their life cycle (e.g. extraction and processing of raw materials, batching and mixing, transportation of raw materials and final product, activities during useful life). Life cycle assessment (LCA) is defined as “the compilation and evaluation of the inputs, outputs and potential environmental impacts of a product system throughout its life cycle” (ISO14040 1997). With such a broad scope of potential impacts, a LCA perspective is useful for assessing the environmental performance of these materials. Prior to conducting a comparative LCA study on different concrete materials it is necessary to examine a variety of software packages for this specific focus. The paper presents the LCA for four mix designs (conventional concrete and concrete with fly ash, slag, or limestone as cement replacement) using three LCA tools. Three key evaluation criteria required to assess the quality of analysis are: adequate flexibility, sophisticated and complex analysis, and useful and high-quality outputs. The life cycle inventory (LCI) data available within each tool is assessed based on data quality metrics including reliability, completeness, and relevance to this study.
ISO (1997) Environmental Management. Life Cycle Assessment: Principals and Frameworks. ISO 14040
One-Year Performance Evaluation of Municipal Concrete Sidewalks using Coarse and Fine Recycled Concrete Aggregate
Abdurahman Lotfy, Ahmed El-baghdadi
Dr. Abdurahman Lotfy, Lafarge Canada Inc. Mr. Ahmed El-baghdadi, Lafarge Canada Inc. (Presenter)
Sustainable development is a global ambition, and arguably the innovative key to future development. To address the need for proper disposal of concrete rubble, coupled with a growing scarcity of high quality virgin aggregates near urban centers, the recycling of hardened concrete into aggregate for new concrete production has attracted much attention. This paper summarizes the results of one-year experimental study on Class C2-32 concrete pavements. Results are reported with respect to mechanical properties and durability aspects of recycled aggregate concrete, compared to its conventional virgin aggregate equivalent. The impacts of replacing virgin aggregate with Recycled Concrete Aggregate (RCA) are discussed in this paper. Mixes were evaluated with replacements of coarse aggregate up to 30% (by volume) and with 20% replacement of both fine and coarse aggregate. Overall performance of recycled coarse aggregate in new concrete was found to be equivalent to that of conventional concrete. Evaluation was performed by testing fresh, hardened and durability properties. Fresh and hardened properties of mixes incorporating coarse recycled aggregate exhibited equivalent performance to the benchmark design, while mixes incorporating the full granular RCA were within acceptable limits, showing a minor decrease in flexural strength and increased susceptibility to salt scaling. The results of the field trial are presented in this paper and monitoring is still on-going. In addition, professional contractors have commented on the ease of placement of RCA concrete. The success of this pilot project paved the way for further implementation of RCA in various new concrete applications whilst promoting sustainable growth.
AbdurahmanLotfy, Ph.D., P.Eng.
Regional Manager, New Products Development, Innovation & Commercialization, Lafarge, Toronto, ON
PERFORMANCE OF MEMBRANE BIOREACTOR VERSUS ACTIVATED SLUDGE AT A DOMESTIC WASTEWATER TREATMENT PLANT IN OMAN
Mahad Baawain, Abdullah Al-Mamun, Ahmed Sana, Buthaina Al-Wahaibi
Dr. Mahad Baawain, Sultan Qaboos University (Presenter) Dr. Abdullah Al-Mamun Dr. Ahmed Sana, Sultan Qaboos University Ms. Buthaina Al-Wahaibi
The main objective of this study is to evaluate two wastewater treatment methods that are implemented at a sewage treatment plant (STP) in Oman; Conventional Activated Sludge (CAS) and Membrane Bioreactor Technology (MBR). The CAS STP receives its domestic wastewater through tankers while MBR STP receives its wastewater through sewer network. Samples from influent raw sewage, biological aeration tank and treated effluent from both systems were analyzed for physical, chemical and biological properties. The obtained results showed that the raw sewage of the CAS STP can be categorized as high strength concentration compared to medium strength concentration for the MBR STP. The removal efficiency achieved at the CAS plant for TSS, TN and BOD are 97%, 57% and 98% respectively. The accomplished removal efficiency by the MBR plant are 98%, 82% and 98% for TSS, TN and BOD, respectively. However, the removed amounts of the TSS, TN and BOD in the CAS plant were 437, 40 and 442 kg per 1000 m3, respectively, compared to 147, 37 and 206 kg per 1000 m3 respectively, for the MBR plant. Thus, the CAS plant was able to remove higher amounts of pollutants compared to the MBR plant.
PILOT-SCALE BIOFILTRATION OF IRON- AND MANGANESE - CONTAMINATED GROUNDWATER AT LOW IN-SITU TEMPERATURES AT A WATER TREATMENT PLANT IN SASKATCHEWAN
Sandeep Raja Dangeti, Babak Roshani, Joyce McBeth, Wonjae Chang
Mr. Sandeep Raja Dangeti, University of Saskatchewan (Presenter) Dr. Babak Roshani, Delco Water Division, Delco Automation Inc. Dr. Joyce McBeth, Canadian Light Source Dr. Wonjae Chang, University of Saskatchewan
Iron (Fe) and manganese (Mn) are common elements of concern in groundwater in in the Canadian Prairies. Biological filtration that stimulates indigenous Fe- and Mn-oxidizing microorganisms that are naturally present in groundwater is often considered a cost-effective water treatment option. One of challenging aspects of biological treatment is that low temperatures significantly hinder microbial metabolic activity. This study focuses on enhancing cold-adapted, indigenous microbial populations for Fe and Mn oxidation at the in situ low temperature (8 Â°C) of a pilot-scale biofilter at the Langham water treatment plant in Saskatoon. The pilot-scale biofiltration system consists of two aerated biofilters connected in series, designed to remove Fe in Filter 1 and Mn in Filter 2. The growth of biofilms was promoted either on conventional plastic filter media or on anthracite. Rapid oxidization of iron occurred through both filters in one month (99% removal, p-value <0.05). After several months, Mn removal was successfully achieved in Filter 2 when it contained anthracite (97% removal, p-value <0.05). Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM/EDS) and Inductively Coupled Plasma (ICP) analyses confirmed the removals of Fe and Mn below the water quality criteria. The increase in Oxidization Reduction Potential (ORP) in Filter 2 strongly correlated to the decrease in Mn concentrations in the aqueous phase. Adsorption of Mn on anthracite, which was confirmed by an additional batch experiment, likely contributed to the biological removal and/or bacterial immobilization of Mn in Filter 2. Culture-dependent microbial assessments coupled with the Leucoberbelin method indicated the presence of Mn-oxidizing bacteria in the biofiltration system.
Quantitative Assessment of Residential and Non-residential Solid Waste Generation in Alberta and British Columbia
Aklima Zerin Asha, Kelvin T. W. Ng
Ms. Aklima Zerin Asha, University of Regina (Presenter) Dr. Kelvin T. W. Ng, University of Regina
Alberta and British Columbia were selected in this study to investigate the solid waste generation characteristics in Western Canada. Waste data from 1998 to 2010 were collected from Statistics Canada. It was found that non-residential waste generation was noticeably higher than residential waste generation during the study period. On average, the residential waste in Alberta and British Columbia represented about 34% and 40% of their total non-hazardous waste generation, respectively.
Per-capita rates were used in the study to minimize the impact of differences in population growth rates. During the study period, the average total waste generation rates in Alberta and British Columbia were 3.23 kg/capita?day and 2.47 kg/capita?day, respectively. The percentage difference of these rates was about 26.7%. On the other hand, the average residential waste generation rates were similar in the provinces, with 0.97 kg/capita?day and 0.91 kg/capita?day in Alberta and British Columbia, respectively. The percentage difference between the provinces was much smaller (about 6.4%) in this case. The results suggested that non-residential wastes coming from the institutional, commercial, and industrial sectors might be responsible for the higher per-capita total waste generation rates in Alberta. Socio-economic factors affecting generation rates were also considered in the study. Family income and educational attainment were positively related to the residential waste generation in the provinces. On the contrary, no significant correlation was observed between generation of non-residential wastes and economic performance factors (gross domestic products, and agricultural cash receipts).
Recycling concrete construction and demolition wastes: A proposed financial feasibility model
Omar Farahat, Samer Ezeldin
Mr. Omar Farahat, American University in Cairo (Presenter) Dr. Samer Ezeldin, AUC
The construction industry is a very dynamic field. Every day new technologies and methods are invented to speed up the process and increase its efficiency. This paper examines the recycling of concrete construction and demolition (C&D) waste to reuse it as aggregates in other structural applications for projects in the Middle East. This study focuses on the technical and financial components of concrete recycling plants emphasizing on the three main types of concrete recycling plants; stationary, mobile and traditional plant settings according to capacity, production rate, country of origin, etc.
These findings are gathered and grouped to obtain a comprehensive cost-benefit financial model to demonstrate the feasibility of constructing a concrete recycling plant in the Middle East. The type currently being implemented is the traditional one; however, according to the calculations of the model presented in this research, the mobile type has generated the most profits among the other types, stationary and traditional. Furthermore, a sensitivity analysis is conducted to provide verification on the model. The exercise of the sensitivity analysis is a change in parameters and then the results are logically tested to verify the correctness of the model by iterating the expense with the highest impact by -20%, -10%, 10% and 20%. The sensitivity analysis showed that administrative, salaries and cost of goods sold expenses had the most impact on the model.
Moreover, a developed user friendly model specialized to forecast revenues, expenses and profits is available in softcopy to be used by any user to help him/her in taking decisions related to his/her investment. This guides investors and contactors to choose the suitable and most profitable type of equipment based on the project type.
Geotechnical and Geological Engineering
Hydrotechnical and Water Recourses Engineering
A SIMULATION GAMING MODEL FOR INTEGRATED RIVER BASIN MANAGEMENT
Kai Wang, Evan Davies
Mr. Kai Wang, University of Alberta (Presenter) Dr. Evan Davies, Department of Civil & Environmental Engineering
This paper introduces the Bow River Basin Simulation Gaming Model (BRSGM) as a decision-support tool that can be used to evaluate the effectiveness of various water management strategies. The model, the subject of this paper, contains the main water use sectors in the Bow River Basin – agricultural, municipal, industrial, recreational, and environmental sectors – and water supply, which are connected through water allocations and other water, land, financial management, and technology policies. Model outputs include indicators of basin-scale sustainability that integrate social, economic, and environment components at an annual time step, as well as important output variables for each water use sector, such as crop yields, agricultural profit, municipal water use, power generation, conventional oil and gas production, mining production, manufacturing value added, water recreational values in a representative reservoir park, and environmental water use. Thus, the model explicitly represents the connection between management strategies and the complex water resources system and provides a comprehensive view of the basin water sustainability in a social, economic, and environmental context. Finally, the model will be used as a component of a Bow River Basin water management simulation game – currently under development – to identify potential risks of alternative policy selections and improve participants’ understanding of the management trade-offs and feedbacks between different water sectors.
A systematic approach to estimating the 300-year runout for dense snow avalanches
For residential zoning near a snow avalanche path in Canada, three zones are usually identified: Red (no new construction), Blue (restricted development) and White (unrestricted development). The Red-Blue boundary depends on the runout from a 300-year dense snow avalanche. This runout is estimated along the centerline of the path using up to four sources: historical records, trim lines in vegetation, statistical runout models, and dynamic runout models. The confidence and return period for these four estimates vary. Example 1: the extreme trim line in a forested path is of high confidence and typically indicative of a large dense snow avalanche within the last 100 years. The date of the extreme avalanche is known approximately e.g. 60-63 years, but confidence in the return period is only moderate because the trim line is from a single event. Example 2: the statistical runout estimate is typically of moderate confidence and for a return period of approximately 100 years. Traditionally, these estimates with different levels of confidence and return periods are combined with the consultant’s experience. In the proposed approach McClung’s (2005) recently validated Space-Time model is used to adjust the estimates from each of the four sources to a 300-year runout. The 300-year runout for a dense flow avalanche is then calculated as a confidence weighted average, reducing the subjectivity. To compensate for high uncertainty, sometimes because less than four sources are available, the 300-year runout can be extended. Examples are presented to illustrate the proposed method.
Detailed Field Measurements of Red River Flow Characteristics
Masoud Goharrokhi, Shawn Clark
Mr. Masoud Goharrokhi, University of Manitoba (Presenter) Dr. Shawn Clark, University of Manitoba
~~Sufficient resolution of measured flow data under different hydraulic conditions is of prime importance to develop an understanding of river processes and to enable accurate numerical modelling. The objectives of this study were to obtain and assess a wide range of hydrometric and hydrodynamic data of the Red River in Winnipeg under varying flow conditions. Basic geometric parameters, water surface profile, dimensionless numbers (Froude, Reynolds, and entropy parameter), the stage-discharge rating curve, boundary friction through the use of three different coefficients, roughness height, and local and reach scale hydraulic shear stress were determined using the field data. An acoustic Doppler current profiler was used to collect spatial and temporal data along 10 km of the Red River between the South Perimeter Bridge and Fort Gary Bridge over a 2 year period. High resolution water surface elevations at the reach extremes were also collected. These comprehensive results provide a better understanding and suitable knowledge for modeling of the complicated phenomenon occurring on the Red.
Development of Alberta Lake Level Index: A Simple Approach
Zahidul Islam, Michael Seneka
Dr. Zahidul Islam, Alberta Environment and Parks (Presenter) Mr. Michael Seneka, Alberta Environment and Parks
We have developed a simple method of lake level index for 33 lakes across Alberta. Water level throughout the year is compared to historical patterns in recorded data. It is then ranked based on five possible categories, ranging from the highest classification of "much above normal" to the lowest, "much below normal." A mid-range classification is considered "normal". The indicator is based on the assumption that a lake is in its normal range if the lake level falls between the historical upper and lower quartiles. Based on the indicator, in 2007, most were normal-to-much above normal (28 out of 33) after which there was a general declining trend through to 2010. In 2013, levels for 24 lakes are reported, and 19 of them are in the normal-to-much above normal categories and 5 in the below normal categories. This indicator is intended to portray natural conditions and contribute to the general knowledge of water in Alberta. It informs context and does not necessarily require specific management actions be taken on a regular basis. However, the indicator can increase understanding of other water issues such as water quality, fisheries, and recreation. This information can help guide other lake or watershed management decisions.
Improved forecasting of persistent deep slab avalanches with a decision support tool
Michael Conlan, Bruce Jamieson
Dr. Michael Conlan, University of Calgary (Presenter) Dr. Bruce Jamieson, University of Calgary
Persistent deep slab snow avalanches are generally difficult to forecast because of the relatively large depth to the failure layer. A decision support tool was developed to help professionals forecast the likelihood of such events. The tool follows a threshold sum approach, where users answer yes/no questions and all yes answers are summed and compared to threshold values. The questions were derived from parameters important in the release of persistent deep slab avalanches. The questions comprise three sections: snowpack conditions, weather conditions, and avalanche observations. Values within each of the questions were obtained from three independent data sources, including persistent deep slab avalanches that were accessed, a dataset of historical persistent deep slab avalanches, and an expert opinion survey. A classification tree was used to determine the threshold tool sum that separates days with higher likelihood from days with lower likelihood. For a dataset of 110 days, the tool correctly classified 89 % of days where naturally triggered persistent deep slab avalanches were observed and 74 % of days where avalanches were not observed. The tool also indicates whether persistent deep slab avalanches triggered from skiers or snowmobiles are possible, depending on the local snowpack conditions. The output of the tool only indicates the likelihood of such events within a forecast region and cannot predict when or where they will occur. The tool may help streamline the decision making process for some avalanche forecasters in mountainous terrain.
Potential Impact of Climate Change on Water Availability of Brahmaputra River Basin
Sarfaraz Alam, Md. Mostafa Ali, Zahidul Islam
Mr. Sarfaraz Alam, Bangladesh University of Engineering and Technology Dr. Md. Mostafa Ali, Bangladesh University of Engineering and Technology Dr. Zahidul Islam, Alberta Environment and Parks (Presenter)
Brahmaputra River Basin (BRB) is one of the largest basins among Ganges-Brahmaputra-Meghna (GBM) river system carrying enormous volume of water through Bangladesh. The response of BRB due to potential climate changes is one of the key issues to be investigated due to its socio-economic and environmental vulnerability. A semi-distributed physically based hydrological model of the BRB has been developed using the Soil Water Assessment Tool (SWAT). The model has been calibrated and validated for the streamflow measured at the Bahadurabad station of the main stem Brahmaputra for the climate normal period (1981 to 2010). Then, the impact of climate change on water availability has been assessed by applying different climate change scenarios of selected General Circulation Models (GCMs) of Intergovernmental Panel on Climate Change (IPCC). The selection of GCMs was based on the Representative Concentration Pathways (RCPs) scenarios for the 21st century. The high resolution spatial distribution of temperature and precipitation of these GCMs were generated using the pattern scaling technique in order to apply them into the hydrological model. Model results subsequently provided the projected trends of average annual and seasonal streamflow of BRB for the three climate change periods of 21st century, viz. as 2010-2039 (2020s), 2040-2069 (2050s), and 2070-2099 (2080s). The present hydrological model provides an opportunity for further development to be undertaken.
SURFACE WATER MANAGEMENT CHALLENGES IN NORTHERN ALBERTA OILFIELD SITES
Ali Roshanfekr, Hossein Souri
Mr. Ali Roshanfekr (Presenter) Mr. Hossein Souri
Northern Alberta is well known for its Steam Assisted Gravity Drainage (SAGD) sites. These are oilfield sites used for heavy oil production consisting of central processing facility, well pads and source water wells. In many cases the access roads to these facilities crosses water courses, wetlands and flowing fens (muskeg). In order to design and construct the roads for these sites, various permits from Alberta Environment including AER and ESRD must be obtained and many regulatory requirements shall be met. In addition, these sites usually require designing two separate systems for collecting clean and potentially contaminated surface water. Among other things, designing the surface water drainage system is another challenge that these SAGD projects are confronted with. Described herein are the design strategies that were invoked to meet the regulatory requirements faced by a real-life SAGD project in Northern Alberta.
Transient thermal analysis of a concrete spillway
Ali Nour, Abdelhalim Cherfaoui, Gocevski Vladimir, Andre Bergeron, Sonia Tevi-Benissan, Frédéric Perreault
Dr. Ali Nour, Hydro-Québec (Presenter) Mr. Abdelhalim Cherfaoui Mr. Gocevski Vladimir, Hydro-Québec Mr. Andre Bergeron Mrs. Sonia Tevi-Benissan Mr. Frédéric Perreault
This paper presents a feasibility study of casting with 4.7 m concrete lift height as well as casting along the entire length of a chute of a concrete spillway. To this end, a detailed transient thermal analysis was carried out based on concrete heat of hydration and site conditions (wind, ambient temperature, etc.). Using this analysis, a representative temperature profile was determined and , in a subsequent mechanical analysis, was combined with other types of loads in the analyses made for steel reinforcement design. The transient thermal analysis was conducted based on a realistic construction scenario. Moreover, a detailed 3D finite element model was prepared and analysis was conducted - taking into account thermal concrete-rock contact - using Abaqus Standard solver. Two scenarios corresponding to two concrete lift heights were examined : (i) the standard height of 2.3 m (current practice), and (ii) the desired 4.7 m height which significantly enables the reduction of casting time and associated work. Results obtained from the two scenarios are presented and compared. This study demonstrates the benefits of the advanced numerical tools for rational design of strategic hydraulic structures.
Innovations in Engineering
Tools to evaluate the vulnerability and adaptation of infrastructure to climate change
It is fundamentally clear that climate change represents a profound risk to the performance of engineered systems and to public safety in Canada and around the world. As such, professional engineers, asset managers and decision-makers must address climate change adaptation as part of their primary mandate – the protection of the public interest, which includes life, health, property, economic interest and the environment. Climate change produces significant changes in statistical weather patterns resulting in a shifting foundation of the base design data. Physical infrastructure systems designed using this inadequate data are vulnerable to failure, compromising public and economic safety.
The paper starts by presenting an overview of the impacts of climate change as witnessed in the last decade. It presents an overview of tools available to decision-makers and infrastructure practitioners to consider climate change impacts to infrastructure, from planning to operations and maintenance. It offers a review of available tools to develop community adaptation plans, to assess the climate components in policy, and to evaluate the engineering vulnerability of infrastructure assets and systems. Although the article describes some international and research tools, it focuses on processes and methodologies that have been used by public agencies and municipalities to identify and quantify risks, as well as develop climate change adaptation solutions.
Finally, Engineers Canada’s PIEVC Protocol, a methodology used in more than 40 instances across Canada to evaluate the vulnerability of infrastructure is described. The Protocol has been applied to a wide spectrum of infrastructure: roads, highways, bridges and associated structures; potable water, wastewater and storm water systems; electrical transmission infrastructure and dams; buildings; airports; and coastal infrastructure. The case studies cover all regions of Canada.
Use of Geographic Information System (GIS) Technology for Optimized Landfill Site Selection in Regina, Canada
Syed Ahmed, Joe Piwowar
Mr. Syed Ahmed, DST Consulting Engineers Inc. (Presenter) Mr. Joe Piwowar, University of Regina
The selection of a site for a new landfill is a complicated task because of social, geological, environmental, hydrological and economic issues. In this study we applied an optimized land use site selection based on overlay analysis using a Geographic Information System (GIS). Several important factors and criteria were considered, including terrain elevation, slope, depth to ground water, distance to surface water, site accessibility via the existing road network, and land use. Thematic maps of these criteria were developed and overlaid in a GIS to identify candidate locations for the landfill. The final site recommendation was selected from these candidates based on minimum site size and nearby population density. Our approach is unique because the environmental factors were considered as the primary governing factors, and the social parameter was only applied for the final selection of the candidate site.
Calibration of an MPS model by simulating a pool-and-weir fishway
Tibing Xu, Yee-Chung Jin
Mr. Tibing Xu, University of Regina (Presenter) Dr. Yee-Chung Jin, University of Regina
Pool-and-weir fishway is an important type of fishway to aid migrate fish ascending upstream through obstructions in rivers or streams. It consists of a set of fishway pools separated with weirs. Water flows through this type of fishway either by plunging into the fishway pool or streaming above weirs. In this study, a pool-and-weir fishway flow is modelled by using a mesh-free method, moving particle semi-implicit method (MPS). This method is widely used to simulate flows in hydraulic engineering such as dam-breaking flow, open-channel flow, hydraulic jump and weir flows. Due to the Lagrangian nature of the method, it is good at handling large deformation and free surface problems since moving particles are used instead of fixed meshes in the traditional Eulerian methods. This flow in fishway is successfully reproduced by MPS. The water surface profiles are compared with experimental measurements, and good agreement is achieved.
Non-linear finite element analysis to predict ultimate pressure capacity of a nuclear power plant containment structure
Ima Tavakkoli Avval, M. Reza Kianoush, Homayoun Abrishami
Ms. Ima Tavakkoli Avval, Ryerson University (Presenter) Dr. M. Reza Kianoush, Ryerson University Dr. Homayoun Abrishami, Ryerson University
The design requirements for nuclear containment structures when subjected to internal pressure has changed in recent years to improve the margin of safety against failure during a severe accident. The primary objective of this article is to calculate the ultimate pressure capacity (UPC) of a containment structure (CS). The major components of a CS consist of a cylindrical prestressed wall, and a dome. The structure is supported by a rigid reinforced concrete base slab. In this study, the UPC is predicted using the finite element method. For the containment structure, the most reliable results is obtained by a full 3D model. The ANSYS program is employed to predict the response of the structure. The major challenges for modelling the prestressing system is to accommodate parameters affecting prestressing forces. To introduce the prestressing forces, initial strains are applied to discrete tendon elements. Even though this approach increases the complexity of the problem; it represents the most realistic modeling of prestressing system. This method is more appropriate in comparison to the equivalent force approach in previous studies. Both methods are discussed and the results of UPC are compared together. It is observed that the CS investigated in this study meets the design requirement of the currents standards. The structure behaves linearly up to 1.5 design pressure and UPC is estimated as 2.3 times the design pressure. The response of the structure using the discrete model for the prestressing tendons and the equivalent prestressing force approach vary by
Numerical modeling of the stress ribbon Terwillegar Park Footbridge
Nolan Rettie, Shahab Ahmed, Manoj Medhekar
Mr. Nolan Rettie, Stantec Consulting (Presenter) Mr. Shahab Ahmed, Stantec Consulting Ltd. Dr. Manoj Medhekar, Stantec Consulting
The Terwillegar Park stress ribbon footbridge in Edmonton, Alberta began construction in 2014. The cable supported structures transfer large horizontal tension forces to the abutments, which are typically resisted by ground anchors. The vertical sag at midspan varies due to changes in temperature. Therefore, these structures do not require expansion joints, but geometry control during construction is critical. The superstructure analysis consisted of numerical modeling and analytical calculations. Results from both methods were compared to provide validation of the design. The numerical modeling methods are described. CSiBridge finite element software was used to create a staged construction analysis model. The construction model considered the various stages of construction including ground anchor stressing, tensioning the bearing cables, precast panel placement, cast?in?place concrete placement, post?tensioning the stressing cables, wearing surface and handrail installation. The model used constraints, as well as rigid and flexible links between nodes to accurately represent the appropriate construction stage. Construction and in?service temperature effects were included. Cable, truss, frame and shell elements were used for various bridge components. The numerical construction model compared well with the analytical results and will provide the designer with the ability to verify bridge geometry throughout all construction stages.
A New Repair Material for Concrete Pavements
Ahmed Ghazy, M. T. Bassuoni
Mr. Ahmed Ghazy, University of Manitoba (Presenter) Dr. M. T. Bassuoni, University of Manitoba
Efficient repair of concrete pavements typically requires a rapid setting material that can be placed and hardened within a relatively short period of time for quick opening of traffic. While numerous high early-strength cementitious repair materials are commercially available, many of these materials are vulnerable to early-age cracking, poor bonding, and premature deterioration, for example due to incompatibility with the existing pavement. On the other hand, concrete incorporating fly ash, which is known for its improved long-term performance, is not typically recommended as a repair material. The delay in setting time, strength gain and microstructural development at early-age of fly ash concrete impede its wider acceptance as a repair material for concrete pavements. Nevertheless, these performance limitations can be mitigated by incorporation of nanoparticles in the mixture design of fly ash concrete. In the present study, an effort was made to develop nano-modified fly ash concrete as a repair material for concrete pavements. The performance of the newly developed mixtures was compared to that of two commercial cementitious products customarily used by the regulatory bodies in Manitoba, Canada for partial depth repair of concrete pavements. The experimental scheme comprises tests on fresh, hardened and durability properties relevant to the performance of repair materials for concrete pavements. Due to their ultrafine nature, the addition of a small dosage of nano-silica particles efficiently catalyzed the kinetics of hydration reactions in the cementitious matrix at early-age. The results indicate that nano-modified fly ash concrete has superior performance in terms of strength development, bonding, and resistance to salt-frost scaling, and thus it presents a viable option for repair of concrete pavements.
A Thermodynamic Framework for Constitutive Models of Concrete Incorporated of Plasticity and Damage Property
Duoxin Zhang, wenjun qu, Wei Zhou
Mr. Duoxin Zhang, Tongji University (Presenter) Dr. wenjun qu Mr. Wei Zhou
Strain softening and stiffness degradation induced by damage and permanent deformation caused by the plasticity were taken into account, and the evolution of damage and plastic variable were used to describe their mechanism. The plasticity and damage mechanics were incorporated into the thermodynamics, four types of energy potential functions and dissipation function, which considered coupling effect of plastic and damage have been developed. Along with flow rule of generalized plasticity, the evolution laws of internal variables were formed, given 32 possible ways of formulating constitutive behaviour. The incremental response entirely established by differentiation of the two potentials and by standard matrix manipulation. Finally, the constrained conditions introduced successfully through the Lagrangean penalty functions and strengthened the applications of developed thermodynamic framework.
Analysis of RC circular bridge columns retrofitted with fiber reinforced polymer under axial and lateral cyclic loading
In the last decades non-metallic fiber reinforced polymers (FRP) materials developed as a practical alternative material for manufacturing reinforcement for concrete structures. The novelty of the composite material lies in its outstanding mechanical properties, low weight, and satisfactory durability even in an aggressive environment. These properties effectively utilized to enhance the safety of various civil infrastructures. However, the monotonic and lateral cyclic behavior of FRP composites sheet retrofitted reinforced concrete (RC) bridge columns has been investigated extensively, but analytical knowledge needs to be enhances, especially in the area of different FRP retrofitted bridge columns under lateral load. The objective of this study is to investigate analytically the effectiveness of different retrofitting techniques in upgrading the seismic performance of non-ductile RC bridge columns. The quasi-static cyclic analysis and non-linear static pushover analysis is conducted for the case studies. The seismic performance of the studied columns is evaluated in terms of load carrying capacity, flexural ductility, hysteric behavior and energy dissipation of capacity under quasi-static cyclic load along with constant axial load. The analysis results is verified based on available existing quasi-static cyclic test results and the analysis provides good agreements with the experimental results.
Analytical Model to Determine Long Time Multipliers for Fully Cracked and Uncracked Sections
Kyle Karschner, Andrew Scanlon
Mr. Kyle Karschner, Penn State University Dr. Andrew Scanlon, Penn State University (Presenter)
Kyle Karschner1 and Andrew Scanlon2
Long- time multipliers are commonly used in design codes and specifications such as CSA A23.3 and ACI 318 to compute time-dependent deflections of reinforced concrete members. These multipliers are convenient for design due to their simplicity of application. However, as a result of their simplicity they do not account for many factors that influence time-dependent deflections. This paper presents an analytical method based on a time-stepping procedure to trace deformations in cracked and uncracked sections under sustained loads. A parametric study is conducted to assess the sensitivity of the solution to the various parameters involved and implications for design are discussed.
1.Â SGH, Boston, Massachusetts.
2. Contact author: Penn State University, firstname.lastname@example.org, 814 867 0151
BEHAVIOUR OF UNSTIFFENED WIDE-FLANGE MEMBERS SUBJECTED TO TORSIONAL MOMENT THROUGH ONE FLANGE
Muhammad Ahmad, Robert Driver, Logan Callele, Bo Dowswell
Mr. Muhammad Ahmad, University of Alberta (Presenter) Dr. Robert Driver, University of Alberta Mr. Logan Callele, Waiward Steel Fabricators Ltd. Dr. Bo Dowswell, ARC International, LLC
It is common for unstiffened wide-flange structural members to be loaded by an adjoining member through the flange. While many load types are readily accommodated by routine design, when the member is loaded torsionally the behaviour is complex and no widely accepted design rules exist. One common example occurs when handrail posts are attached to the top flange of a floor beam, where the horizontal design guard forces induce torsion in the beam. Another is encountered in industrial structures such as pipe racks where a beam that is rigidly connected to a column flange resists weak-axis bending, resulting from hydraulic pipeline forces, that in turn loads the column torsionally. Because of the lack of codified design criteria for cases where the torsional member is unstiffened, it is common to add full-depth stiffeners to transfer the forces to the entire cross-section. However, this adds considerable cost to the joint and is often unnecessary. Unstiffened members subjected to torsional moment through one flange engender phenomena of both single-flange torsion and web bending. Localized bending of the web at the web-to-flange junction and torsion of the flange connected directly to the member delivering the load constitute a complex shared force-resisting mechanism. This paper elaborates on the behaviour of unstiffened members subjected to torsional moment using finite element analysis. Characteristic behaviours of wide-flange members under this type of loading have been explored by conducting a comprehensive parametric study, varying parameters such as length of member, section depth, flange thickness, web thickness, and flange width.
Best Practices for Design and Construction of Aluminum Structural Plate Structures
Anna West, Kevin Williams, Phil Carroll
Ms. Anna West, Atlantic Industries Ltd (Presenter) Mr. Kevin Williams, Atlantic Industries Ltd Mr. Phil Carroll, Atlantic Industries Ltd
Buried bridges constructed of corrugated aluminum structural plate are a lightweight, economical and environmentally friendly solution to traditional bridges in many applications up to spans of 16 m. Aluminum structural plate resists corrosion, impact and scratches as a result of the spontaneously forming oxide layer. This oxide layer, alumina (Al2O3), is dense and adheres well to the aluminum alloy substrate when exposed to oxygen carrying environments, such as water or atmosphere. While aluminum structural plate has been on the market for over 50 years, there are many uncertainties in industry regarding appropriate environments, capabilities and durability. The objective of this paper is to address those uncertainties by building on previously published literature with conducted laboratory testing and field inspections of existing structures. Results of the laboratory testing on aluminum structural plate substantiated previously documented claims of resistance against salt spray and abrasion. These results were again reflected during the field inspections in various environments (soft water, brackish water, applications utilizing deicing salts, low to moderate abrasion, etc.). While not appropriate for all applications, aluminum structural plate is suitable for roadways utilizing deicing agents in winter months, soft water, brackish water and moderately abrasive conditions. The outcome of this paper is a best practices guideline for the use of aluminum structural plate. The guideline quantifies appropriate environments for aluminum structural plate as well as design and installation practices for various applications.
Bond Behavior of Ribbed-Surface, Headed-End, GFRP Bars Embedded in High-Strenght Concrete
MD SIRAJUL Islam, Khaled Sennah, Hamdy Afefy
Mr. MD SIRAJUL Islam, Ryerson University (Presenter) Dr. Khaled Sennah, Ryerson University Dr. Hamdy Afefy, Tanta University, Egypt, Ryerson University, Canada
Glass Fiber Reinforced Polymer (GFRP) bars as a proper substitute for traditional reinforcing steel bars not only eliminate the durability problem due to corrosion of reinforcing steel, but also provide remarkably enhanced capacity due to their high tensile strength compared to that of the steel bars. This paper presents the experimental findings of pullout tests conducted on GFRP bars embedded into high-strength concrete blocks covering different parameters. The studied parameters were bar diameter size, embedment length, bar end condition (headed), and concrete cover to bar. Based on the results of the parametric study, the bond stress was shown to be inversely proportional to the embedment length and bar diameter as expected. In addition, the smaller concrete cover appeared to have significant effect on bond stress, leading to side blow-out failure rather than bar pullout or concrete splitting in the case of headed-end GFRP bars. In addition, the GFRP bar with headed-end showed significant increase in pullout strength compared to that for the straight-end bars. Finally, an empirical expression was proposed to calculate the development length of GFRP bars with headed-end cast in high-strength concrete.Â
Bond Strength of GFRP Bars in Concrete at High Temperature
Hamzeh Hajiloo, Mark Green
Mr. Hamzeh Hajiloo, Queens University Dr. Mark Green, Queen's University (Presenter)
The polymer matrixes currently used for the fabrication of fibre reinforced polymer (FRP) reinforcing bars soften at temperatures approaching the glass-transition temperature (Tg) resulting in reduction of mechanical properties and loss of effectiveness in structural applications. In this paper, the effect of high temperature on the bond between one of the commercially available glass fibre reinforced polymer (GFRP) reinforcing bars and concrete is studied experimentally. Most of the previous experiments have been conducted on smaller sizes, while in many applications larger GFRP bars are used. The bond properties in the temperature range from 20 to 200 °C were studied for the bars of #5(16 mm nominal diameter). Test results showed a reduction of between 14 and 84 % in the bond strength as the temperature increased from 60 to 200 °C, respectively. At elevated temperatures, sand-coated bars showed a high sensitivity to high temperature in terms of bond strength since it relies mostly on the resin at the interface of the bar’s core and the sand coating.
Canada's First Hybrid-Composite Beam Bridge
John Hillman, John Unsworth, Duane Otter
Mr. John Hillman, HCB, Inc. (Presenter) Mr. John Unsworth, Canadian Pacific Railway Dr. Duane Otter, Transportation Technology Center, Inc.
Long before Accelerated Bridge Construction (ABC) became ubiquitous in highway bridges, it was standard practice for the railroad industry. Rapid installation and long service lives are not just desirable qualities, they are essential. The Hybrid-Composite Beam (HCB) provides a lightweight, safety redundant and sustainable option for the next generation of railroad bridges with these essential qualities. It is equally well suited for ABC of highway bridges.
The HCB is comprised of three main sub-components that are a shell, compression reinforcement and tension reinforcement. Design, fabrication, endurance testing, constructibility, inspectabilty and maintainabilty will be addressed from several points of view resulting from a unique collaboration between TTCI, CP and HCB, Inc. Although fourteen HCB bridges comprising twenty-nine spans have now been constructed, the evolution of this technology started with the first proof of concept on the HTL at TTCI in November 2007. This paper chronicles the seven year journey from proof of concept that culminated in the first HCB bridge in Canada and the first revenue service HCB railroad bridge anywhere in the world. It will also demonstrate how a HCB unit damaged during transportation was efficiently repaired to restore its original integrity to safely carry heavy axle load traffic on a CP mainline through the Canadian Rockies.
In addition, the paper presents what happens when the internal components of an HCB Bridge are exposed or damaged. Examples will be provided showing current research related to impact testing and residual capacity of a damaged HCB.
Central LRT Rehabilitation in Edmonton, Alberta
Opened in 1978, the station structure, located directly underneath Jasper Avenue, Edmonton’s major artery, consists of precast pre-stressed concrete cross beams supported by L-beam edge girders. The structure has been leaking from the road surface and vulnerable to decades of chloride attack from the road salts used during prolonged winter road clearing operations. A study performed in 2008 found that the two major concrete L-beam support girders, spanning over 200 m each, supported by a series of concrete piles, were corroded at the bearing seat. The pre-stressed concrete beams which the girders were supporting, and which were ultimately supporting the roadway, were found to have been affected to a lesser extent and were rehabilitated using CFRP wrap. The corroded bearing seat of the L-beam was relieved of the load from the pre-stressed concrete beams by transferring the load directly to the piles using steel support members installed where such measures were feasible. Shear friction reinforcement was used to transfer the load directly from the cross-beams to the areas of concrete L-beam that were unaffected by chloride attack and where steel columns were not practical to install.
The rehabilitation of Edmonton’s Central Light Rapid Transit (LRT) Station required the use of adaptive design approaches to overcome substantial existing spacial restrictions, co-ordination to ensure that a multi-disciplined team approach was ultimately successful and that the station could maintain full functionality during construction. A sustainable approach to the design was implemented to ensure that the work completed would help sustain Edmonton’s infrastructure for the next 75 to 100 years.
Circular concrete columns reinforced with steel and GFRP under simulated earthquake loads
Arsalan Tavassoli, Shamim Sheikh
Mr. Arsalan Tavassoli Dr. Shamim Sheikh, University of Toronto (Presenter)
To address the issue of corrosion of steel in concrete structures, GFRP is slowly gaining acceptability as a replacement of steel. In an effort to evaluate the feasibility of GFRP bars and spirals as internal reinforcement in columns, an extensive research program is underway at the University of Toronto. A total of seventeen 356 mm diameter concrete columns have been tested under simulated earthquake forces which included constant axial load and cyclic lateral displacement excursions. All columns were reinforced laterally with GFRP spirals. Nine columns contained longitudinal GFRP bars while eight had longitudinal steel bars. Results from a select group of specimens will be presented in this paper in the form of moment vs. curvature response and shear vs. deflection behaviour. A number of ductility parameters related to curvature, displacement, and energy dissipation are used to evaluate the performance of specimens. Columns containing longitudinal and lateral GFRP reinforcement demonstrated a stable post elastic response accompanying large deformability. Columns reinforced with longitudinal steel and GFRP spirals also displayed excellent behaviour with higher stiffness and larger shear and moment capacities mainly due to the linear elastic behaviour of GFRP bars until rupture at a strain of approximate 0.02.
Cracking serviceability limit state for precast concrete tunnel segments
Mehdi Bakhshi, Verya Nasri
Dr. Mehdi Bakhshi, AECOM (Presenter) Dr. Verya Nasri, AECOM
Precast segmental linings are increasingly used in the mechanized tunneling methods using TBM-bored shield tunnels. Tunnel segments are designed following the approach of limit state design recommended by national and international codes and guidelines. Ultimate limit state (ULS) and serviceability limit state (SLS) are specified in these design codes. The former focuses mostly on the ultimate capacity of a structure prior to failure, while the latter is mainly associated with the availability of a structure for users, such as the constraints on deflection or deformation and cracking of a member under loading. The serviceability condition is particularly important for tunnel linings, because cracking can be very detrimental for its consequences in terms of durability, especially if the tunnel is exposed to an aggressive environment or excessive water inflow. In this paper, required serviceability verification for the design life of precast concrete segmental linings is discussed. Necessary design checks for SLS are introduced including stress, deformation and cracking for the main section of precast segment. This paper focuses on cracking serviceability limit states of concrete segments with particular attention to different types of reinforcement including steel bars and fibers. Methods to calculate crack width at SLS are discussed. Maximum allowable crack width for tunnel linings specified in various guidelines and standards are presented. Finally a case of mid-size tunnel is presented to illustrate the applicability of the proposed approach.
DAMAGE IDENTIFICATION USING FREQUENCY SENSITIVITY FUNCTIONS
Ayman Thabit, Mohamed Abdel Mooty, Ezzat Fahmy
Mr. Ayman Thabit, The American University in Cairo (Presenter) Mr. Mohamed Abdel Mooty Dr. Ezzat Fahmy, The American University in Cairo
The inevitable occurrence of damage in structures necessitates the availability of an efficient and reliable damage identification routine. The recent boom in construction and the surge in the scale of structures have proven that relying solely on the classical approach to damage detection lacks practicality. Vibration-based techniques, which emerged in the early 1970s, have been successfully utilized in many damage detection applications. One of the most widely known vibration-based methods relies on detecting damage through the measured shift in resonant frequencies. Although this technique has the advantage of simplicity of the measurement process, its sensitivity to damages in large scale structures has been a subject of investigation. Additionally, the influence of variations in ambient conditions has been found to be measurable. This paper presents a new technique for detecting damage in beam-type structures by utilizing the frequency sensitivity functions of the first few vibration modes. The proposed method was successfully tested on Finite Element models of single-spanned beams. The effect of changes in both uniform and gradient temperatures was also addressed in this research. The capability of the presented method in identifying damage in relatively long period structures was investigated by applying the proposed technique on a numerical model of a cable-stayed bridge. Â The method was also tested using the results of pervious experimental investigation in which damage was simulated at different locations of a cantilever beam. The presented technique showed promising capabilities in identifying the location and magnitude of damage.
DESIGN OF A TWO-SPAN SEMI-INTEGRAL ABUTMENT BRIDGE WITH CONTINUOUS CURVED STEEL GIRDERS
Armando Chocron, Tony Cicchetti Cicchetti, Patrick Clinton, Mehdi Khodadadian, Christopher Mercieca, Kayhan Turker, Sameh Salib, Khaled Sennah
Mr. Armando Chocron, Ryerson University (Presenter) Mr. Tony Cicchetti Cicchetti Mr. Patrick Clinton, Ryerson University Mr. Mehdi Khodadadian Mr. Christopher Mercieca Mr. Kayhan Turker, Ryerson University Dr. Sameh Salib Dr. Khaled Sennah, Ryerson University
In Canada, in general, and within the Greater Toronto Area (GTA), in particular, there is a constant demand to improve the transportation infrastructure. Herein, the subject project involves a new 2-span continuous curved steel girder bridge which merges a major road with a highway. The bridge is of a semi-integral abutment type which has been adopted frequently in North America over the past years due to its favourable characteristics. In these bridges, the deck extends beyond the abutments and then bends vertically down as a ballast wall to shift the expansion joints outside the structure itself. This serves to protect both superstructure and substructure components especially the bearings which are delicate and costly components to repair or replace. Moreover, in order to provide the most durable and cost effective bridge design, ‘Box’ and ‘I’ girder alternatives were investigated. During the design phase, as well as during construction, the complexity of curved bridges poses several challenges. Among them, are the significant torsional straining actions induced in both individual girders and entire deck system due to their curved geometry. Therefore, the analysis, design and construction should accommodate the related stability concerns associated with girders erection and deck construction as well as during the entire service life of the bridge. Further, the subject project has a unique challenge regarding the vertical clearance required for the vehicular traffic flow under the bridge. Through a sensitivity study, various deck design options were investigated from both technical and financial aspects in order to optimize the satisfaction of this requirement.
Durability of Concrete Containing Sulphide-Bearing Aggregate: Assessment of Test Methods
Oxidation of sulphide-bearing aggregates can result in severe damages in concrete structures. The mechanism of damage is believed to consist of two steps: (a) oxidation of the aggregate associated with an increase in volume, and (b) formation of sulphuric acid. Both steps produce damage to concrete. This presentation presents an investigation into developing accelerated test method that can be used to evaluate the potential of sulphide-bearing aggregate to oxidize and cause damage to concrete. Different aggregates are tested using different testing regimes. It was found that the level of damage increases with the increase in the level of sulphide content in the aggregate. Cycles of wetting in lime water at 23oC/drying at 60oC and 5oC/drying at 60oC produced some expansion in concrete samples. The use of oxidizing agent was found to accelerate the expansion; however, the obtained expansion was also affected by the length of the soaking and heating cycles.
Effect of Bar Type on the Punching Shear Behaviour of GFRP-RC Interior Slab-Column Connections
Ahmed Gouda, Ehab El-Salakawy
Mr. Ahmed Gouda, University of Manitoba (Presenter) Dr. Ehab El-Salakawy, University of Manitoba
Ahmed Gouda1 and Ehab El-Salakawy2
1 Ph.D. Student, Dept. of Civil Eng., University of Manitoba, Winnipeg, MB, Canada
2 Professor and CRC, Dept. of Civil Eng., University of Manitoba, Winnipeg, MB, Canada
Abstract: This paper presents the results of an experimental program that was carried out to investigate the effect of bar type on the behaviour of GFRP-RC interior slab-column connections. A total of three full-scale isolated Interior slab-column connections were constructed and tested to failure. One slab was reinforced with conventional steel bars, one with sand-coated GFRP bars and one with ribbed-deformed GFRP bars. The slabs were square with a side length of 2800 mm and a thickness of 200 mm. The central column had a 300-mm square section and extended above and below the slabs for a length of 1000 mm. The connections were subjected to a vertical shear force, V, simultaneously with unbalanced moment, M with a constant “M/V“ratio of 0.15 m. All test specimens failed due to punching shear of the central column through the slab. The test results showed that the specimens reinforced with sand-coated and ribbed-deformed GFRP bars had 25 and 33%, respectively, lower capacity, in reference to the steel reinforced one. It was also concluded that the ribbed-deformed GFRP bars showed comparable behavior to the sand-coated counterparts in term of cracks pattern. In addition, the test results were compared to the shear provisions of the Canadian standard CSA/S806-12 and the American guideline ACI 440.1R-06.
Effect of Different Curing Compound Applications on Concrete Pavements
M. Tiznobaik, M. T. Bassuoni, Murray Bruce Peters
Mr. M. Tiznobaik, University of Manitoba (Presenter) Dr. M. T. Bassuoni, University of Manitoba Mr. Murray Bruce Peters , City of Winnipeg
Premature deterioration is a common concern for all types of concrete structures. To help mitigating this issue, the concrete hardening process is required to take place in a manner which provides optimum hydration development. This can be achieved through proper and adequate curing practices of concrete. The effect of curing on the performance of concrete is essential at controlling its mechanical and durability performance during service. Depending on the adiabatic conditions, type of application and project specifications, the curing approach may vary considerably (e.g. continuous fog spraying for long time, application of a curing compound, etc.). The aim of this research project is to assess the effect of three different curing compound applications (no curing, one coat of curing compound, two coats of curing compound) on the behavior of concrete pavements, and thus projecting their long-term durability. The project involved experiments on cores extracted from a newly (August 2014) constructed pavement sections in Mulvey Avenue, WinnipegÂ in comparison to corresponding specimens produced from similar concrete under laboratory conditions. Absorption and rapid chloride permeability tests were conducted on specimens to study the effect of the different curing methods, and the results were statistically analyzed by the analysis of variance method. The overall trends indicate that applying curing compounds is critical to ensure moisture retention in concrete for efficient hydration reactions and microstructural development. Even one coat of curing compound thoroughly applied to concrete is sufficient for achieving target strength and durability characteristics.
Effect of FRP external retrofitting on axial capacity of RC column when subjected to blast Load
Bessam Kadhm1, Husham Almansour2, Murat Saatciouglu3
The objective of this study is to investigate the effect of high performance carbon fiber reinforced polymer HP-CFRP external protection on the axial capacity and lateral damage of RC columns when subjected to simulated blast load. In this study, CFRP laminate is designed and optimized in a multi-scale process to : (i) maximize the structural efficiency of the confinment and energy absorption; (ii) Reduction of the residual deformations; (iii) minimize the use of the materials; and (iv) practical field application of the protection layer. Several protected and non-protected half scale concrete columns are tested using shock simulated blast load. The columns were subjected to axial compression of 40% of the column ultimate axial capacity. The axial load, deformation and strains were measured throughout the test. In order to examin the residual capacity of the tested columns, they were loaded axialy up to ultimate load capacity after the application of the blast load.
The results show that significant reductions in the residual deformation, strains and damage of the protected columns versus non-protected columns have been achieved. Further, more than 90% of the applied axial load has been recovered in the protected columns after the blast shoot. The average residual static axial capacity of the protected columns after the blast load was 30%-50% higher than the design capacity of the non-protected columns. It has been observed that the application of HP-CFRP protection laminate results in significant changes in the trends and peak values of strains and time of occurrence in the reinforcing steel and the surface of the concrete in critical sections.
Corresponding authors email: email@example.com
Effect of lateral deformations on vertical stiffness of rubber bearing isolators with rectangular cross section
Moein Ahmadipour, Shahria Alam
Mr. Moein Ahmadipour, The University of British Columbia (Presenter) Dr. Shahria Alam, University of British Columbia
Seismic isolation bearings are intended to lengthen superstructure’s vibration period by their low lateral stiffness. Their vertical stiffness, however, should remain in a safe range in order to withstand gravity loads imposed by the superstructure. Part of the bearing’s vertical load-carrying capacity is provided by closely-spaced internal steel shims and the rubber, as an incompressible material, bonded to the steel reinforcements. As the bearing undergoes lateral deformations, its vertical stiffness and, as a result, its load-carrying capacity, tends to decrease, which might have catastrophic consequences. In this research, the vertical stiffness of rectangular rubber bearings is studied. The effect of lateral deformations on the vertical stiffness is investigated through three methods: 1) The two-spring method, 2) Overlapping area method and 3) Linear interpolation method. The effect of manufacturing central holes is also investigated and found not to be considerable to be taken into account. The effect of lead core in lead-core rubber bearing isolators is also studied and found to be the dominant factor in determining the vertical stiffness. It is observed that, unlike the two-spring method, the two other methods suggest a linear trend for vertical stiffness reduction in bearings with a rectangular cross section. It is also shown that the overlapping area method suggests a steeper decrease and gives the most conservative prediction of the vertical stiffness.
Effect of the design resistance of towers on the extent of transmission line cascading failures
Sébastien Langlois, Oussama Lamine Naouali, Frédéric Légeron
Mr. Sébastien Langlois, Université de Sherbrooke (Presenter) Mr. Oussama Lamine Naouali, Université de Sherbrooke Dr. Frédéric Légeron, Université de Sherbrooke
Transmission line structures may suffer catastrophic losses when cascading failures occur. These events are caused by dynamic loads very often related to the sudden ruin of conductors or other mechanical equipment. One strategy that is commonly used to mitigate the risks of large losses is the insertion of more robust, anti-cascading supports at specific locations along the line, for example at every 10 towers. This strategy limits the maximum number of failed supports. However, to further reduce financial losses, it would be interesting to better control the extent of these events. On the other hand, many authors have developed numerical models to reproduce the dynamic behavior of transmission lines subject to a broken conductor event. This paper studies, using a non-linear time history finite element model, the possibility to limit the extent of cascading failures simply by designing the towers to resist a certain portion of the dynamic load caused by a broken conductor. The model is first validated with existing small-scale experiments. Then, a parametric study is performed on a typical line section composed of tubular steel towers to provide graphs for the number of supports affected as a function of the tower resistance. Variables studied include the following: conductor mechanical tension, span length, and insulator length. The results of this study show that the numerical method and the strategy presented could allow transmission line designers to make decisions of their tower resistance that could limit the extent of possible cascading failures to a certain desired number of towers.
Effectiveness of Cross-Frame Layout in Skew Composite Concrete Deck-Over Steel I-Girder Bridges.
Muhammad Kashif Razzaq, Khaled Sennah, Ghrib Faouzi
Mr. Muhammad Kashif Razzaq, University of Windsor, Department of Civil & Environmental Engineering (Presenter) Dr. Khaled Sennah, Ryerson University Dr. Ghrib Faouzi, University of Windsor
Canadian Highway Bridge Design Code (CHBDC) and AASHTO-LRFD Bridge Design Specifications allow cross-frames to be parallel to the skew angle if less than 200. However, for skew angles greater than 20Â°, both design specifications require the cross-frames to be perpendicular to the longitudinal axis of the girder. Literature review showed that the effect of cross-frames layout in skew composite concrete slab-over steel I-girder bridges on load distribution among girders is as yet unavailable. In this paper, three cross-frame layouts commonly used in skewed bridges are considered, namely: parallel cross frames to the skew support lines (parallel layout), perpendicular cross-frames to the skew support lines (perpendicular-continuous layout) and perpendicular cross-frames to the skew support line with staggered arrangement between girders (perpendicular-discontinuous layout). A three-dimensional finite-element modelling was conducted to determine the magnification factor for moment and shear in bridge girders with different skew angle, cross-frame layout and stiffness, span length, number of design lanes and truck loading conditions. The finite-element results are presented in terms of cross-frame forces at bridge supports, differential vertical displacement of cross-frame at obtuse corners, girder longitudinal bending moment and vertical support reactions. Results showed that parallel cross-frame layout can be used for skew angles up to 300. Also, skew bridges with perpendicular-discontinuous cross-frame layout exhibited better structural performance than the perpendicular-continuous cross-frame layout. Moreover, results showed that the maximum positive moment in exterior girder is located at the girder mid-length for right-angle bridges while this location shifts towards the obtuse corner with increase in bridge skewness.
EFFECTS OF INTERFACIAL GAPS ON THE IN-PLANE BEHAVIOUR OF MASONRY INFILLED RC FRAMES
Chuanjia Hu, Yi Liu
Mr. Chuanjia Hu, Dalhousie University (Presenter) Dr. Yi Liu, Dalhousie University
Four scaled specimens, including three concrete masonry infilled reinforced concrete (RC) frames and a bare RC frame were tested to investigate the effect of interfacial gaps on the in-plane behaviour and strength of masonry infilled RC frames. The specimens were subjected to an in-plane lateral load applied at the frame top beam level to failure. The interfacial gap between the beam and the top of the infill was considered with two magnitudes, 7 and 12 mm. The load vs. lateral displacement behaviour and failure mode for each specimen were presented and discussed. Results showed that in general, the ultimate stiffness, first crack strength and ultimate strength decreased as the top gap size increased while the deflection at the ultimate load increased as the gap size increased. Compared with the specimen with no gaps, a top gap of 7 mm resulted in 3% reduction in the lateral strength and 40% reduction in the lateral stiffness of the infilled system whereas a top gap of 12 mm resulted in 22% and 72% reductions in the lateral strength and the lateral stiffness of the infilled system, respectively.Â
Experimental investigation on the bond behaviour of GFRP bar in high performance concrete
Jennifer Lu, Khaled Sennah
Ms. Jennifer Lu, Ryerson University (Presenter) Dr. Khaled Sennah, Ryerson University
This paper discusses the bond characteristics of GFRP bars in high performance concrete (HPC)
by pullout testing of GFRP bars embedded in concrete cube samples. Two types of GFRP bars
with ribbed or sand-coated surface were used with or without casted head. The nominal bar
diameters used for sand-coated bars were 15.875 and 19.05 mm and for ribbed surface bars were
16 and 20 mm. The surface dimension of concrete cubes was 300×300 mm for headed end bars
and was 200×200 mm for straight end bars. Three embedment lengths of 4, 6, and 8db were used
for straight end bars, while it was 0 or 4db plus the head length for headed end bars, where db is
the bar diameter. To investigate the effect of concrete clear cover on the bond behaviour, three
cases of centric, 40 and 60 mm clear cover were used for 16 mm bars, while only centric and 40
mm clear cover were used for 19 and 20 mm bars. Five identical cube samples were casted for
each case as prescribed by the code. In total, 250 concrete cube samples were casted due to
different bar type, head, and diameter and also embedment depths and concrete clear cover.
Pullout tests were carried out to obtain associated failure loads. Experimental results were
compared with available formulas for development lengths in the building and bridge codes and
application of any adjustment factor was discussed. Load-slip behaviour of the bars on both free
and loaded end was also studied.
Experimental study of fatigue behaviour of cracked steel plates repaired with high and low modulus carbon fibre reinforced polymers
Syed Mobeen, Jung-June Roger Cheng
Mr. Syed Mobeen, University of Alberta (Presenter) Dr. Jung-June Roger Cheng, University of Alberta
Fatigue behaviour of edged cracked steel plates repaired with carbon fibre reinforced polymers (CFRP) was studied experimentally under tension- tension fatigue loading, with stress range of 180 MPa and the stress ratio of 0.1. Main parameters were the CFRP modulus, adhesive thickness and adhesive shear strength. Two different moduli of CFRP were used; 165 GPa and 67 GPa. Test results showed that lesser adhesive thickness resulted in 12% reduced fatigue life for higher modulus CFRP type because of induced higher shear stresses and corresponding more adhesive failure in it, that resulted in more patch delamination and the reduced fatigue life. Lower stiffness CFRP repairs achieved higher fatigue lives because of higher adhesive shear strength although the induced shear stresses in adhesive layer was expected to be higher but on the other hand the adhesive had higher shear and bond strengths that prevented the adhesive shear failure or the patch delamination, thus resulted in higher fatigue life. Replacing lower strength adhesive with higher shear and bond strength adhesive in higher modulus CFRP repairs resulted in increased fatigue lifeÂ just because of the improved adhesive bond and shear strengths. The experimental study highlighted the impact of adhesive shear and bond strengths on the fatigue life of cracked steel plates repaired with identical axial stiffness CFRP patches differed by the adhesive properties.
FATIGUE BEHAVIOR OF A DEVELOPED UHPC-FILLED PRECAST DECK JOINT IN BULB-TEE BRIDGE GIRDER SYSTEM REINFORCED WITH SAND-COATED GFRP BARS
Imad Eldin Khalafalla, Khaled Sennah
Mr. Imad Eldin Khalafalla, Ryerson University (Presenter) Dr. Khaled Sennah, Ryerson University
~~This paper investigates experimentally the use of non-corrosive glass fiber reinforced polymer (GFRP) bars to reinforce the precast deck slab joints in prefabricated bridge bulb-tee (DBT) girders system. In this system the concrete deck slab is cast with the prestressed girder and casting closure strip between precast flanges to provide continuity between the girders. The aim of this study is to develop joint detail between the precast flanges of the DBT girders, incorporating sand-coated GFRP bars with headed ends embedded in a closure strip filled with ultra-high-performance concrete (UHPC). Two actual-size, GFRP-reinforced, precast concrete deck slabs were erected to perform fatigue tests and determine their behavior under CHBDC truck wheel loading. Each slab has 200 mm thickness, 2500 mm width and 3500 mm length in the direction of traffic. Fatigue behavior and fatigue life of the GFRP reinforced precast (DBT) bridge girders system were investigated using different schemes of cyclic loadings (accelerated variable amplitude cyclic loading as well as constant amplitude cyclic loading followed by loading the slab monotonically to failure). Overall, the test results demonstrated the excellent performance of the developed closure strip details.
FLOW OF FOAM MIXTURES ON INCLINED FLUMES AND SURFACES
Amir H. Azimi
Foam mixtures can potentially be employed for preventing underground fire in mining industries, land stabilization and environmental protection. Experimental tests were conducted to model the two-dimensional flow of foam mixtures for two slopes of 10 and 15 degrees. Foaming agent with two different foam-water ratios of 0.1 and 0.2 were used. Correlations were developed to predict the foam length and its frontal velocity with time using dimensional analysis. It was found that the normalized frontal velocity of foam mixtures decreased with normalized time with a slope of ?0.6 in logarithmic scales. To study the effect of bed slope on the flowability of foam mixtures, spreading tests were carried out for four slopes of ? =10, 12, 15 and 18 degrees. Variations of the foam front location in spreading test showed that the foam front location advanced almost linearly with time. For foams with lower foam-water ratio, variation of the foam length with time is independent of the surface slope for ?>10 whereas for foam mixtures with higher foam-water ratio, the foam front advances linearly with time and the frontal velocity increases with increasing the bed slope.
GFRP-RC Columns under reversal-cyclic loading
Mahmoud Ali, Ehab El-Salakawy
Mr. Mahmoud Ali, university of manitoba (Presenter) Dr. Ehab El-Salakawy, University of Manitoba
Using fiber reinforced polymers (FRP) reinforcement as main reinforcement in reinforced concrete (RC) structures becomes a viable solution to steel corrosion-related problems. Unlike steel, FRP bars do not yield, instead, they exhibit high tensile strength along with linear elastic behaviour up to failure. However, it is well-documented that the inelastic behavior of steel in RC structures is common in dissipating earthquakes-induced energy. Accordingly, the performance of FRP-RC structures under seismic loading needs to be investigated.Â The objective of this research project is to study the effect of using glass (G) FRP longitudinal and stirrup reinforcement on the performance of concrete columns under reversal cyclic loading. Two full-scale columns prototypes, with 1650-mm long and 350-mm square cross-section, were constructed and tested under simulated seismic load conditions. The column specimen represented part of first storey column between the foundation and point of contra-flexure; therefore, the heavy-reinforced footing was fixed to the laboratory strong floor to simulate rational fixity to the column. The experimental results showed that both GFRP and steel columns were successfully able to sustain drift ratios higher than the values required by both the American Concrete Institute and the National Building Code of Canada. This indicates that the GFRP-RC columns can successfully sustain the gravity load in the presence of the seismic excitations.
Implementation of Simplified Design Method for Energy Dissipating Devices in Retrofitting of Seismically Isolated Bridges
Seyyed Behnam Golzan, Sébastien Langlois, Frederic Legeron
Mr. Seyyed Behnam Golzan Mr. Sébastien Langlois, Université de Sherbrooke (Presenter) Mr. Frederic Legeron
This paper presents an innovative method for the optimum design of seismically isolated bridges incorporating energy dissipating devices. For an isolated bridge subjected to an earthquake, the deformation is concentrated in the isolators. This greatly reduces the seismic forces transmitted from the superstructure to the substructures. However, some factors such as space limitations, stability requirement, etc. limit the allowable deformation taking place across an isolator. To control the deformation of the isolators, supplemental energy dissipating devices can be introduced into the isolation system. This may in return increase the total structure force and the merit of adding dampers has to be evaluated properly. In this study, a simplified damper design method has been used to optimize the performance of an isolated structure. This method is based on a simplification of the system and by setting objectives for displacement reduction as well as acceptable force increase. Based on this approach, damper stiffness and damping ratio is determined as a function of pier and isolator stiffness. The method provides a range of added stiffness and damping that will be needed to reduce the total displacement of the structure while controlling the increased structural force. Response spectrum analysis method has been performed to validate the method for a typical isolated bridge structure. The numerical simulation showed a close relation with the proposed simplified method. It is concluded that the proposed simplified approach has the potential to optimize the performance of isolated bridges incorporating energy dissipating devices.
INCORPORATION OF LIGHTWEIGHT AND RECYCLED AGGREGATES FOR CONCRETE CURING
Mohamed El Ghonemy, Ahmed Hammam, Mariam Ismail, Marwan Roushdy, Mohamed Abdel Raouf, Mohamed Abou-Zeid, Ezzat Fahmy
Mr. Mohamed El Ghonemy, The American University in Cairo Mr. Ahmed Hammam, The American University in Cairo Ms. Mariam Ismail, The American University in Cairo Mr. Marwan Roushdy, The American University in Cairo Dr. Mohamed Abdel Raouf, The American University in Cairo Dr. Mohamed Abou-Zeid, The American University in Cairo (Presenter) Dr. Ezzat Fahmy, The American University in Cairo
Adequate curing of concrete is a fundamental step in concrete manufacturing to meet performance and durability requirements. Internal curing is an emerging technique that can provide water to concrete for extended durations towards thorough hydration of the cement and reduced cracking. This work addresses potential use of two types of aggregates for internal curing. Perlite light weight aggregates as well as recycled concrete aggregates were incorporated at three dosages each to replace the coarse aggregates.
Conventional concrete mixtures were prepared as fully cured by water, cured by a curing compound and with no curing. Fresh concrete and hardened concrete properties were evaluated including slump, unit weight, compressive and flexural strength as well as shrinkage. The results reveal that the incorporation of pre-wetted/saturated lightweight aggregates can lead to a significant enhancement in concrete workability and durability through reduced shrinkage.Â
INVESTIGATION OF THE BEHAVIOUR OF PIPE ELBOWS DUE TO THE BOURDON EFFECT FOR DIFFERENT BOUNDARY CONDITIONS
Md Abdul Hamid Mirdad, Muntaseer Kainat, Diana Abdulhameed, Marwan El Rich, Michael Martens, Samer Adeeb, Roger Cheng
Mr. Md Abdul Hamid Mirdad, University of Alberta (Presenter) Mr. Muntaseer Kainat, University of Alberta Ms. Diana Abdulhameed, University of Alberta Dr. Marwan El Rich, University of Alberta Mr. Michael Martens, TransCanada PipeLines Ltd. Dr. Samer Adeeb, University of Alberta Dr. Roger Cheng, University of Alberta
Steel pipe elbow is a common feature in piping systems which is used to change the direction of a straight pipe. The Bourdon effect is the phenomenon of the elbows tending to straighten out when pressurized. Shemirani et al. (2014) studied the influence of the Bourdon effect on the ovalization developed in the elbows for fixed boundary conditions. They showed that there is an increase in the stresses within the elbow; however, this effect is not at all addressed in the Canadian oil and gas pipeline code CSA Z662-11. Kainat et al. (2014) studied how geometric imperfections influence the Bourdon effect in the elbows for fixed boundary conditions. Here we extended the study of the Bourdon effect by focusing on the behavior of pipe elbows using different boundary conditions and neglecting any initial geometric imperfections. Nominal pipe sizes of 12, 36 and 42 inch were selected with constant thickness throughout the pipe. 90ยบ pipe elbow models with two straight pipe attachments have been analyzed using finite element analysis software ABAQUS for different boundary conditions at the ends of the straight pipe attachments. The ends have been allowed to expand in the radial direction upon pressurization to prevent stress concentrations. Under normal operating pressure for (80% SMYS) hoop stress; the Bourdon effect, von Mises stresses and reaction force in the pipe elbows were investigated. From the analysis results, the effect of the boundary conditions on the mechanical response of the elbow is investigated.
La Crete Biomass Power Facility
Architects and engineers are responsible for designing and building efficient structures with a minimum use of materials and energy. In current paper, the structural design of La Crete Biomass Power plant will be presented. The power plant is located in La Crete, Alberta, Canada. This plant is projected to power over 30,000 Canadian homes. The La Crete Biomass Power Facility will utilize well-established technology to provide communities with an efficient source of energy. The facility is an eight-storey building with a total height of 40 m. One of the structural challenges of this project is a huge 960,000 kg mass (biomass boiler) suspended throughout the entire structure. A system of steel hanger rods is selected to hold and suspend the Eight-storey boiler in its place.
The construction material utilized in this project is steel. Steel structures have been widely used in many applications of civil engineering. The use of steel as a construction material breeds many advantages, such as light structural mass, low maintenance cost, ductility, durability, strength and king fatigue life.
One of the most important design considerations for steel structures supporting heavy mass is the dynamic response especially for post-disaster buildings. Etabs software has been used to evaluate mode frequencies, perform the dynamic analysis of steel structures and optimized the sections of steel members taking into consideration different load cases.
Keywords: steel structures; power plant; earthquake loads; wind loads; mode frequency.Â
Pilot Study of Blast Performance of Reinforced Concrete Reservoir Walls
Dan Palermo, Jin Fan, IOAN NISTOR
Dr. Dan Palermo, York University (Presenter) Mr. Jin Fan, University of Ottawa Dr. IOAN NISTOR, University of Ottawa
Reinforced concrete reservoir tanks are commonly used for water and wastewater storage and treatment. Given their function and importance to society, intentional or accidental blast loading of such structures could pose serious implications.
This paper presents experimental results of two scaled reservoir walls based on a prototype reservoir tank with the capacity to retain 10,000 m3 of water. The reservoir tank walls were scaled to match the geometric limitations and loading capacity of the shock tube housed in the Structures Laboratory at the University of Ottawa.
The reservoir walls were designed and analyzed following the design method prescribed in Circular Concrete Tanks without Prestressing, published by the Portland Cement Association (PCA). The PCA method is based on the American Concrete Institute (ACI) 350 specifications, but with some differences in the design provisions. In this study, the simplified analysis was verified with an elastic analysis using SAP2000.
The experimental program was conducted with a shock tube that has the capability to impose short duration loads with characteristics similar to those of live explosives. The reservoir walls were subjected to incrementally increasing blast pressures to cover both elastic and inelastic response.
The results presented in this paper includes a discussion of the reflected pressures and impulses imposed on the walls; while the performance will be presented through displacement- and reinforcement strain-time histories, cracking patters, and failure modes.
PREDICTING LOAD DEFLECTION RESPONSE OF WOOD I-JOISTS WITH FLANGE NOTCH
M. Shahidul Islam, Shahria Alam
Mr. M. Shahidul Islam, University of British Columbia (Presenter) Dr. Shahria Alam, University of British Columbia
Canadaâ€™s 400 million hectares of land area are covered with forest, which is 43.6 percentage of its total land area. Through a sustainable forest management this huge forestry resources can be utilized without creating any impact to the global environment. Construction of civil infrastructure with timber is a viable option for utilizing this huge resource. Timber I-joist is an engineered building construction element produced from solid timber and Oriented Strand Board (OSB) as flange and web, respectively. Timber I-joists are commonly used in building construction due to easiness of passing the service conduits and ducts through openings in the OSB web of I-joists and the passageway for service conduits and ducts usually made without considering the structural integrity of the system. This research study investigated the ultimate capacity of wood I-joists in the presence of flange cut. A total of 100 specimens were tested with various sizes and locations of openings in the flange. 10 specimens were tested as control beams with no openings. I-joists were tested with four points bending test in two different span lengths of 12 feet and 20 feet to evaluate the load carrying capacity of the I-joist. Based on the test results, linear and non-linear regression models were developed for the load-deflection response of each series of I-joists and Akaike Information Criterion (AIC) has been calculated to determine the best fit model. It is found that the linear models are well fitted for predicting the load capacity of the I-joists for structural analysis.
Prediction of Strength Properties of Engineered Cementitious Composites using Artificial Neural Network
Shirin GhatrehSamani, Ali Ehsani Yeganeh, Khandaker Hossain
Ms. Shirin GhatrehSamani (Presenter) Mr. Ali Ehsani Yeganeh Dr. Khandaker Hossain, Ryerson University
This paper describes the development of Artificial Neural Network (ANN) models for the prediction of compressive strength of the Engineered Cementitious Composite (ECC) based on mix design parameters. A database consisting of large number of ECC mix designs from previous and current research studies are used for training and validation of ANN models. The influence of mix design parameters on the strength properties are evaluated to determine the appropriate input variables for the ANN models with optimized network architecture. The performance of ANN models is found to be good based on various statistical indicators. The ANN models can be used confidently for the optimization of ECC mix design parameters to obtain targeted strength properties.
Keywords: Artificial Neural Network, Engineered Cementitious Composite, Strength properties, Mix design, Training, Validation
Response of liquid storage steel tanks under wind load
Maryam Rafieeraad, M. Reza Kianoush, Bassam Halabieh
Ms. Maryam Rafieeraad, Ryerson University (Presenter) Dr. M. Reza Kianoush, Ryerson University Mr. Bassam Halabieh
Circular storage steel tanks are widely used for storing liquids such as oil, water, agricultural waste and other types of liquids. Such tanks are extremely vulnerable to failure due to buckling while being under construction. At this stage, they are empty with no roof to cause a degree of restraint. As a result, tank walls which are relatively thin are very susceptible to buckling under high wind pressures. Extensive numerical analysis has been conducted using ABAQUS, a non-linear finite element software to investigate the behavior of a failed steel tank in Alberta due to wind load. Internal wind suction is concluded to be the main reason for buckling of the steel tank causing large displacements at the top of the tank. The results were obtained by gradually increasing the magnitude of external wind pressure “q” until the occurrence of failure. In addition, severe yielding that occurred at the base of the structure is attributed to insufficient anchorage at the base of the tank while being under construction. The results of this study shows that yielding of steel can be eliminated by using adequate anchorage at the base. Practical design recommendations are also made to prevent the buckling of thin walled cylindrical tanks under high wind loads. These include providing stiffeners at the top of the tank as well as an internal circumferential bracing system
Shear Behaviour of Z-Shape Steel Plate Connectors Used in Concrete Sandwich Wall Panels
Nabi Goudarzi, Yasser Korany, Samer Adeeb, Roger Cheng
Mr. Nabi Goudarzi, University of Alberta (Presenter) Mr. Yasser Korany, University of Alberta Dr. Samer Adeeb, University of Alberta Dr. Roger Cheng, University of Alberta
Concrete Sandwich Wall Panels (CSWP) consist of two concrete layers with thermal insulation in between and provide thermal and acoustic insulation and protect the building from moisture ingress. These prefabricated CSWP are widely used in North America to enclose buildings and are subject to high out-of-plane wind and seismic loads. Under out-of-plane loading, CSWP may behave as non-composite, semi-composite or fully-composite panels. The degree of this out-of-plane flexural composite action depends significantly on the shear behaviour of the mechanical connectors between the concrete layers. A concrete sandwich wall panel with higher degree of composite action has substantially higher out-of-plane flexural resistance. Hence, the shear response of interlayer mechanical connectors should be optimized to maximize the out-of-plane composite action of CSWP.
Due to their high efficiency in mobilizing out-of-plane flexural composite action, Z-Shape Steel Plate Connectors (Z-SPC) have recently been used as interlayer mechanical connectors in CSWP. This paper reports the experimental results of a total of 6 push-out shear tests on Z-SPC with various thicknesses and widths. Finite element models for the test specimens were created using Abaqus and validated against the experimental results. Both the physical and numerical models were used to investigate the effect of the width and thickness of Z-SPC on their shear strength and stiffness.
The effect of cracking of concrete at the connector-concrete interface was also investigated. The findings of this investigation will be used to optimize the design of Z-SPC and accurately predict the out-of-plane flexural behaviour of CSWP constructed using Z-SPC.
Structural Behavior of UHPFRC-Filled, Transverse C-Joint in Full-Depth, GFRP-Reinforced, Precast Bridge Deck Panels Resting over Steel Girders
Mahmoud Sayed Ahmed, Khaled Sennah
Dr. Mahmoud Sayed Ahmed, Ryerson University (Presenter) Dr. Khaled Sennah, Ryerson University
Precast full-depth deck panels (FDDP) with transverse joints, placed over steel or concrete girders, are efficient in rapid bridge replacement. In this system, grouted pockets are provided to accommodate clusters of shear connectors welded to steel girders or embedded in concrete girders. In this research, ultra-high performance fibre-reinforced concrete (UHPFRC) and high-modulus glass fibre reinforced polymer bars are utilized in the closure strip between the adjacent precast for enhanced strength and durability. Two actual-size, GFRP-reinforced, precast FDDPs were erected to perform fatigue tests using the foot print of the truck wheel loading specified in the Canadian Highway Bridge Design Code (CHBDC). Each FDDP had 200 mm thickness, 2500 mm width and 3700 mm length in the direction of traffic and rest over braced twin-steel girder system. The transverse closure strip between connected precast FDDPs has a width of 200 mm with female-to-female vertical shear key designated as C-shape joint to increase moment capacity along the interface between the UHPFRC and the precast FDDP along the joint. GFRP bars in the precast FDDPs project into the closure strip with a development length of 175 mm. Two types of fatigue tests were performed, namely: (i) high-cyclic constant amplitude fatigue loading followed by loading the slab monotonically to-collapse; and (ii) low-cyclic accelerated variable amplitude cyclic loading. Overall, the test results demonstrated the excellent fatigue performance of the developed closure strip details. In addition, the ultimate load carrying capacity of the slab was far greater than the factored design wheel load specified in CHBDC.
The effect of overload of a bolted connection on its fatigue life: A case study
Shahin Shadlou, Leon Wegner, Timo Tikka
Dr. Shahin Shadlou, University of Saskatchewan Dr. Leon Wegner, University of Saskatchewan (Presenter) Dr. Timo Tikka, Stantec Consulting
In practice, many structures experience random and variable-amplitude loading during their service lives. On that account, the effects of overload on various components have been extensively studied since the 1960s. However, most of the research has focused on individual components and there is a lack of knowledge about the consequences of the overload on an assembled structure. This study investigates how overload of a bolted connection affects its fatigue life by using experimental and numerical methods. The structure chosen for this case study is a sub-assembly of the steelwork used to support the skips used in a potash mine shaft under simulated slam forces from payload skips. After exposing the structure to one million cycles at the design slam load and one million cycles at double the design load, it was subjected to one cycle at five times the design load. Then, the structure was carefully investigated for signs of damage, and slippage of bolts and other components on one another. In addition, the structure was dis-assembled to investigate the presence of local damage, especially in bolts and bolt holes. Moreover, changes to the distribution of load among the bolts and within each component from the intended design values due to slippage or plastic deformation was investigated using finite element analysis. The effect of the overload on the fatigue life of the bolted connection will be presented, discussed, and compared to the well-established fatigue performance of individual components where tensile overload is typically understood to retard crack growth.
The preliminary exploration of underground ant nest materials and structure
Ant nest is a construction body with a complex structure. Natural underground ant nests generally have good air circulation, appropriate temperature and relative humidity, with trees and natural barriers around. Also it has a good physical structure, pressure resistance, waterproof, thermal insulation and moisture effect. The paper first introduced the history and status quo of researches on the material and structure of ant nests and summarized the trend and dynamic of the researches. And then the characteristics of the site selection of underground ant nests were investigated and the interactions among underground ant nests, soil and environment were elaborated from two aspects of behavior characteristics of selecting nest sites and environmental characteristics of ant nests. Finally,the natural underground ant nests were obtained in different geological conditions.The 3D simulation diagram of the internal structure of the nests were made by frozen CNC milling and computer synthesis for the observation of structure characteristics of natural underground ant nests. The structure characteristics of underground any nests were used to preliminary study the bionic design of underground constructions, predict the application prospect of the structure of underground ant nests in civil engineering and propose the practical application value.
Thermal Storage Concrete
Hussein El-Sharkawy, Mohamed El Bably, Omar Ibrahim, Rafik A. Abdel Kodos, Rafik Gendy, Minass Asaad, Amr Fathy, Mohamed Abou-Zeid, Ezzat Fahmy
Mr. Hussein El-Sharkawy, The American University in Cairo Mr. Mohamed El Bably, The American University in Cairo Mr. Omar Ibrahim, The American University in Cairo Mr. Rafik A. Abdel Kodos, The American University in Cairo Mr. Rafik Gendy, The American University in Cairo Ms. Minass Asaad, The American University in Cairo Mr. Amr Fathy, The American University in Cairo Dr. Mohamed Abou-Zeid, The American University in Cairo (Presenter) Dr. Ezzat Fahmy, The American University in Cairo
In recent years there has been a depletion of natural resources, consumption of fossil fuels and a dire need for conserving energy. Thermal storage concrete is a new type of concrete that is likely to store and conserve energy and thereby serving towards a greener environment. Concrete is considered a suitable media to store energy due to its ability to maintain its performance upon exposure to elevated temperatures, its relative-ease in preparation and widespread use worldwide.
In this work aims at achieving better understanding of factors influencing thermal storage concrete. Twelve concrete mixtures were prepared using conventional, rubber and recycled aggregates and were made with various w/c ratios with and without silica fume. Mixtures were tested for fresh properties as well as compressive and flexural strength upon exposure to high temperatures for six hours. Using models and valid equations, concrete heat capacity, conductivity and other relevant heat storage properties were assessed. This study provides useful information regarding the foremost concrete mixtures that are likely to serve for thermal energy storage purposes. The role of various mix design factors in this regard are discussed and categorized
Timber Beams Post-tensioned with Hardwire Sheets
Dagmar Svecova, Hanan Al-Hayek
Dr. Dagmar Svecova (Presenter) Dr. Hanan Al-Hayek, University of Manitoba
Ever increasing traffic demands and environmental exposure of timber bridges have reduced their performance over the years. The large number of these structures in many jurisdictions makes development of effective strengthening techniques essential for planning the maintenance of these structures.Â An experimental program was undertaken at the University of Manitoba to determine the effect of post-tensioning of timber beams using hardwire sheets on performance of these beams. The emphasis of this work was primarily on the flexural behaviour and on the effect of this technique on the stiffness of the timber beams. A total of six salvaged Douglas-Fir creosote treated timber beams were tested in three point bending till failure. The dimensions of beams were 130 mm wide x 330 mm deep x 4500 mm long. The beams were reinforced with GFRP sheets at an angle of 45? in the shear zone to prevent shear failure. The beams were post-tensioned with hardwire sheet on the tension side. Four beams were post-tensioned with medium density hardwire sheets and the other two beams were post-tensioned with high density hardwire sheets. The dimensions of the hardwire sheets were 120 wide x 0.74 mm thick x 5000 mm long. The results showed small increase in the stiffness of the timber beams post-tensioned with medium and high density hardwire sheets on average by 3% and 6%, respectively. The increase in strength was more significant, on average 60%.
Sustainable Development & Infrastructure Management
DESIGN OF A GREEN ROOF CONCRETE UNITS
Mohamed Adamjee, Omar Shalaby, Samer Abadir, Sara Hussain, Mohamed Abou-Zeid, Ezzat Fahmy
Mr. Mohamed Adamjee, The American University in Cairo Mr. Omar Shalaby, The American University in Cairo Mr. Samer Abadir, The American University in Cairo Mrs. Sara Hussain, The American University in Cairo Dr. Mohamed Abou-Zeid, The American University in Cairo (Presenter) Dr. Ezzat Fahmy, The American University in Cairo
A Large Scale Field Test for Snow and Ice Control of Parking Lots, Platforms and Sidewalks (SICOPS)
Liping Fu, S M Kamal Hossain, Faranak Hosseini, Matthew Muresan
Dr. Liping Fu, University of Waterloo (Presenter) Dr. S M Kamal Hossain, University of Waterloo Mrs. Faranak Hosseini, University of Waterloo Mr. Matthew Muresan, University of Waterloo
This paper summarizes the results from a three-year research project entitled “Snow and Ice Control for Parking Lots and Sidewalks (SICOPS)”. The key component of the project is a large scale field experiment on a wide range of strategies, methods and materials used for snow and ice control of transportation facilities, especially parking lots, platforms and sidewalks. The field tests were conducted at a parking lot and several sidewalks located in the City of Waterloo, Ontario over three winter seasons. Approximately 5000 tests were conducted over nearly 100 winter snow events, covering a large number of treatment combinations in terms of material types, maintenance strategies, and treatment techniques under a wide range of winter weather conditions. The field data were then analyzed systematically and rigorously using various statistical techniques for generating quantitative information about the effects of various factors on the snow melting performance of different materials, rates and treatment methods. The major outcome of this effort is a decision support tool for the selection of the most appropriate maintenance strategies, materials and application rates to address the specific maintenance needs of any parking lots and sidewalks under any winter events. The project also included an extensive review of relevant literature and a set of comprehensive surveys of facility users, maintenance contractors, and government agencies. This paper highlights the important findings from the project along with a number of recommendations that can help maintenance contractors and government agencies develop a cost-effective winter maintenance program for snow and ice control of parking lots and sidewalks.
A Model-Based Evaluation of an Eco-Driving System Using Connected Vehicle Technologies
Matthew Muresan, Kamal Hossain, Liping Fu
Mr. Matthew Muresan, University of Waterloo (Presenter) Mr. Kamal Hossain, University of Waterloo Dr. Liping Fu, University of Waterloo
Connected vehicle technologies are often touted for their potential applications to vehicle safety. However, these technologies also have the potential to contribute to a transportation system’s sustainability. Autonomous and connected vehicles provide traffic engineers with many opportunities for emissions reductions, from vehicle routing to a vehicle’s acceleration pattern. This paper presents the results of traffic and emissions micro-simulations that assess an emissions-based intersection approach driving pattern. A simple network was developed using the PTV VISSIM framework. Communication between vehicles and infrastructure on the network was modelled in the software, and vehicles made decisions on their desired acceleration and speeds based on an emissions reduction algorithm. The results of the PTV VISSIM model were fed into the USEPA’s MOVES2010b emissions model to generate an estimate of emissions for each associated scenario. The results of the study show that automated and connected vehicle technologies have the potential to reduce vehicle emissions.
Compatibility Analysis of Travel Time Prediction on Freeway Using Loop Detector
Lu Mao, Xu Wang, Zhijun Qiu
Ms. Lu Mao, University of Alberta (Presenter) Ms. Xu Wang, University of Alberta Dr. Zhijun Qiu, University of Alberta
Travel time is a representative index of travel systems. Several models and tools have been used to predict and estimate travel time, but few of them relate current speed and flow data with future travel time prediction. Differently, this paper combines the time template prediction and corridor travel time estimation together, based on the current point-level speed and volume data, to address the gap in the literature. Firstly, to predict the time stamp and speed of vehicles arriving at each loop detector, the METANET macroscopic traffic model is used for traffic state simulation. METANET takes real-time traffic measurements and simulates traffic state variables in a future time period. Then, segment-level travel time equals the travel time that is derived from the predicted speeds at the time of entering the section. From the piece-wise linear speed-based method (PLSB), the method assumes that speeds are changing linearly, and instantaneous travel time can be calculated. Based on the concept of “first in, first out (FIFO),” this departure time would be the starting time stamp of the next section. The speeds of vehicles are not fixed but instead dynamic, as they change from one moment to the next, so the time of sections would vary. When each section’s time boundaries are defined, the corridor-level travel time can be finally formed from adjacent sections by constructing imaginary vehicle trajectories. This paper tests, validates and links two practical models by using real-time loop detector data on Whitemud Drive in Edmonton, Canada.
Schedule Reliability of a Bus Route Under Bus to Bus and Bus to Infrastructure Connectivity
Willem Klumpenhouwer, SC (Chan) Wirasinghe, Lina Kattan
Mr. Willem Klumpenhouwer, University of Calgary (Presenter) Dr. SC (Chan) Wirasinghe, University of Calgary Dr. Lina Kattan, University of Calgary
There are a number of strategies that transit operators may use to mitigate the randomness inherent in a busâ€™ movement along a route. Many of these strategies have evolved to include real-time information in order to make dynamically informed decisions. One such strategy is the holding control strategy, where certain stops are selected as time points, and early buses are instructed to wait until a scheduled departure time at these points. While extensive research has been done incorporating real-time information into bus operations, little attention has been given to potential advantages gained in using real-time information to control inter-time-point movement. An algorithm is proposed for an early bus, comparing on-board and off-board passenger costs to decide whether to continue to run early or attempt to slow down. The proposed algorithm considers two situations: when inter-time-point stops have published arrival times, and when they must be deduced by the passengers.