2024 Onward
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Item Field Performance of Asphalt Mixture Modified with Reactive Isocyanate Based Modifier(Canadian Science Publishing, 2024-09-04) Tran, Nam; Moraes, Raquel; Taylor, Adam; Timm, DavidThe reactive isocyanate-based modifier chemically reacts with asphalt components, overcoming the issues of increased viscosity and phase separation encountered with conventional modified binders. It can be used to modify binders to meet the highest performance grades currently specified by state highway agencies. This project aimed to demonstrate the constructability of an asphalt mixture modified with the reactive isocyanate-based modifier in the field and compare its performance with that of a control mixture. The project involved milling an approximately 5.0-cm (2-in) thick surface layer of two 30.5-m (100-foot) sections with similar foundation support. One section was resurfaced with a reactive isocyanate-modified mixture and the other with a conventional SBS-modified mix. The mixtures have shown no significant difference in field performance and laboratory performance test results. This study has provided insights into the field applicability of reactive isocyanate-based modifiers in asphalt mixtures, facilitating the ongoing efforts to develop durable road surfaces.Item EXPERIMENTAL AND NUMERICAL STUDIES ON THE PROPOSED STIFFENER DETAILING OF INTEGRAL BRIDGE STEEL H PILES TO ALLEVIATE THE COMBINED ADVERSE EFFECTS OF AXIAL LOAD AND CYCLIC THERMAL DISPLACEMENTS(Canadian Science Publishing, 2024-10-14) Karalar, Memduh; Dicleli, MuratPast research studies demonstrated that local buckling may be observed when the steel H piles (SHPs) at the abutments of integral bridges (IB) are simultaneously subjected to axial load and lateral plastic displacements. The large curvatures and strains associated with local buckling may lead to earlier low cycle fatigue (LCF) failure of the pile under cyclic thermal displacements. Accordingly, first, the detrimental effect of axial load combined with lateral plastic displacements leading to local buckling and accelerated LCF failure of the SHP is demonstrated through experimental testing and finite element modeling and analysis. Then preventive measures to eliminate or delay local buckling are developed and assessed numerically as well as by experimental testing. Numerical simulation and experimental test results revealed that welding longitudinal stiffeners on the flanges successfully prevent the local buckling of the flanges and improve the fatigue life of the pile.Item Characterising the permanent deformation of subgrade soils under seasonal variation(Canadian Science Publishing, 2024-10-11) Carvalho Everton, José Henrique; Erlingsson, SigurdurRutting, a prevalent failure mode in flexible pavements, largely stems from subgrade issues. Despite this, there is a lack of standard protocols to evaluate subgrade rutting or permanent deformation (PD). This study attempted to characterise PD in subgrades, focusing on a poorly graded sand and two silty sands. Moisture contents above and below optimum levels were considered to account for seasonal variations. The research involved adapting a test to assess the PD by determining typical stresses on the subgrade. Moreover, given these soils' unsaturated state and medium- to fine-grained nature, suction is an important factor. Suction-controlled multi-stage Repeated Load Triaxial tests were conducted, and the results were fitted by a PD model modified to account for suction. The characterisation was compared with the subgrade strain criterion used in pavement design solutions. Results indicated discrepancies between the PD characterisation and strain criteria predictions, with the silty sands performing better than the poorly graded sand, consistent with the shakedown theory.Item THE IMPACT OF EXTREME WEATHER EVENTS OF PROJECTED CANADIAN REGIONAL CLIMATE MODEL DATA ON FLEXIBLE PAVEMENT(Canadian Science Publishing, 2024-09-22) Maadani, Omran; Shafiee, Mohammad; Shirkhani, Hamidreza; Hiedra Cobo, JuanThis paper presents findings about the influence of projected data from the Canadian regional climate model on the performance of flexible pavement, building upon the results from previous work where the data was generated and published, in which a general trend of decreasing the design life was observed. Projected temperature is the most important extreme climate impact on flexible roads. Adopting a conservative approach demonstrated that two extreme events of Maximum Mean Annual Air Temperature (MMAAT) and Maximum Summer Average Air Temperature (MSAAT) resulted in significant reduction of 25 years road design life. The observed trend indicates a severity range of 7% to 15% in terms of design service life loss when considering events every year compared to every five years. The findings revealed a reduction in pavement design life by 34%, 50%, 73%, and 90% for historical, short, intermediate, and long-term life cycles in the city of Windsor, respectively.Item Climate Change in Canadian Civil Engineering Curricula: Gaps and Best Practices(Canadian Science Publishing, 2024-07-17) Liu, Paris; Lovegrove, Gordon Richard; Nehdi, Moncef L.This study examines the state of curricula, knowledge, and practices in Canada’s civil engineering programs with respect to climate change, identifies best practices, and formulates recommendations on ways to improve climate change knowledge and skills training for Canadian civil engineering programs. A survey based on the Climate Framework was distributed to 856 civil engineering instructors across all 25 accredited engineering schools listed by Engineers Canada and gathered data on 55 civil engineering climate change related courses, with representation from 20 out of the 25 accredited programs across the country. The results of this study provide important benchmarks to help instructors incorporate most relevant climate change topics and resources into their courses for equipping civil engineering students with the necessary skills to tackle emerging challenges related to the mitigation of climate change and adaptation to wildfires, droughts, sea level rise, increased precipitation, storms, heat domes, floods, earthquakes, and biodiversity loss.Item Impact of Refuge Island in Two-Lane Roads on Pedestrian Crossing Behavior: A Virtual Reality Study(Canadian Science Publishing, 2024-09-19) Haq, Muhammad Faizan ul; Iryo-Asano, Miho; Alhajyaseen, Wael; Samson, Christian J. R.; Zhu , HongCrashes involving pedestrians are particularly common at unsignalized mid-block crosswalks, where, sometimes, vehicles do not yield to pedestrians. A refuge island (RI) is a countermeasure at mid-block crosswalks on two-lane roads to improve safety in pedestrian–vehicle conflicts. This study investigates the impact of RI at unsignalized mid-block crosswalks on pedestrian crossing behavior and conflict severity, considering vehicle approach speed and approach direction. A virtual reality experiment was designed to compare pedestrian crossing behaviors in different scenarios. Results revealed that at higher vehicle approaching speeds, pedestrians tended to accept shorter gaps, leading to a higher rate of unsafe crossings. Generally, in RI setting, pedestrians accepted significantly shorter gaps, which increases the operational efficiency of the crosswalk without significantly affecting the severity of conflicts with vehicles. Furthermore, the subjective evaluation of the pedestrians after the experiment clearly indicated their preference for the RI setting, as they reported a safer crossing experience.Item Quantifying changes in floods under different bathymetry conditions for a lake setting(Canadian Science Publishing, 2024-06-13) Redondo Tilano, Sergio Andrés; Boucher, Marie-Amélie; Lacey, Jay; Parent, JérémyFloods can cause extensive damage proportional to their magnitude, depending on the watershed hydrology and terrain characteristics. Flood studies generally assume bathymetry as steady, while in reality it is constantly changing due to sediment transport. This study seeks to quantify the impact of different lake bathymetry conditions on flood dynamics. The Hydrotel and Telemac2D models are used to simulate floods for a lake with bathymetries from multiple year surveys. The bathymetries differ in bed elevation due to sediment accumulation and/or remobilisation. Results show that bathymetric differences produce a more noticeable effect for moderate flows than for maximum flows. During moderate flows, shallower bathymetries induce higher water levels and larger water extents. For peak flows, differences in water levels and extent are practically negligible for the different bathymetries tested. Higher water levels during moderate flows could produce longer flooding times and affect the community’s perception of flood impacts.Item Application of Reliability Models for Crash Frequency Analysis: Implications for Network-wide Safety Performance(Canadian Science Publishing, 2024-06-28) Deljouyi, Nasim; Patnala, Phani Kumar; Mehran, Babak; Regehr, Jonathan DThe present study demonstrated the potential applications of reliability models for crash analysis of a large highway network. Specifically, three major outcomes of reliability models were investigated: temporal distributions of crashes, reliability score, and expected number of crashes, using 20-year data (2001-2020) of crashes recorded on the Saskatchewan highway network. A series of reliability models were developed for crashes by crash severity, vehicle involvement, and highway type. First, the temporal distributions of crashes on each segment were fit to a statistical distribution. Second, the reliability scores were used to rank the high crash risk segments. Third, the mean expected crash frequency was used to develop network-wide safety performance functions for total and fatal crashes in urban and rural highway segments using Poisson-Tweedie regression models. The developed PTw models showed that the presence of trucks in the traffic composition has a significant effect on crash frequency, especially for urban highway segments.Item Local Calibration of Flexible Performance Models Using Maximum Likelihood Estimation Approach(Canadian Science Publishing, 2024-06-27) Singh, Rahul Raj; Haider, Syed WaqarThis paper uses maximum likelihood estimation (MLE) approach to calibrate bottom-up cracking, total rutting, and international roughness index (IRI) transfer function for flexible pavements. It used four distributions: gamma, exponential, negative binomial, and log-normal, and results are compared with the LS approach. Initially, synthetic data is generated for bottom-up cracking to demonstrate the effectiveness of MLE over the LS approach. Finally, measured data for two hundred and fifty-six new flexible pavements is used from MDOT’s PMS database to calibrate and validate transfer functions. Resampling methods are combined with MLE to improve its robustness. The results show that overall, MLE outperforms the LS approach for synthetic and measured data. The difference is more evident in the case of bottom-up cracking data, which does not follow a normal distribution. Gamma distribution for bottom-up cracking and total rutting, whereas negative binomial for IRI is the most suitable distribution for the MLE approach.Item Identifying Potential Tailgaters Using Matched Case-Control Logistic Regression(Canadian Science Publishing, 2024-04-30) Sahnoon, Iyad; de Barros, Alexandre G.; Kattan, Lina LRoad collisions arise from interactions involving human factors, the environment, and road layout. Driving simulators, widely applied in rear-end collision studies, provide a secure environment to explore human errors, which are not observable through microsimulation tools. These simulators also facilitate the examination of driving behaviour in the presence of connected vehicles. This study aims to identify driver-related factors contributing to rear-end collisions in a driving simulator and to detect potential tailgaters behind a connected vehicle with connected cruise control. Using case-control logistic regression, participants with the potential to be involved in rear-end collisions are considered potential tailgaters, while non-potential participants serve as controls. The results reveal statistically significant factors, such as headway time and maximum brake mean values, in relation to rear-end collisions. Furthermore, employing regression outputs, log relative risk and survival function, with predefined thresholds effectively identifies potential tailgaters, achieving accuracy rates of over 90% and 97%, respectively.Item Determinants of road user behavior at marked midblock crosswalks(Canadian Science Publishing, 2024-04-02) Elsayyad, Mohamed Ibrahim; Muley, Deepti; Alhajyaseen, WaelDrivers do not properly respect pedestrian priority at marked mid-block crosswalks. This study assesses pedestrians and vehicles behavior at such locations. Video recording at two mid-block crosswalks was used to analyze twelve crossing attributes and their correlations. Analysis of 884 pedestrians’ and 2087 vehicle’s data showed that all demographic and crossing related attributes affected the crossing speed and crossing time of pedestrians. The average crossing speed of pedestrians was 1.3 m/s. Only parked car at crosswalk affected the waiting and delay times of pedestrians. Lastly, gender, and crossing related parameters were found to affect the accepted gap of pedestrians. The average accepted gap of pedestrians was 6.17seconds. Vehicle speeds before, at, and after crosswalks were statistically different and had mean values of 19.38kmph, 17.31kmph, and 20.40kmph respectively. Driver yielding rate was found to be 40% and was statistically significantly influenced by gender, dressing style, crossing in-group, and rolling behavior.Item The Current State of Gender-based Diversity within the Field of Canadian Professional Structural Timber Engineering(Canadian Science Publishing, 2024-05-11) Philion, Ethan; Jeanneret, Chloe; Gales, John; Chorlton, BronwynThere is currently minimal data that may be used for retention and recruitment strategies for timber professional engineering in Canada. A comprehensive survey performed in 2022 to address this lack of data is discussed. The survey was generated and analyzed by York University (Canada) and distributed through the Canadian Wood Council’s membership directory. This survey explored participants’ motivations for working on timber-based structural projects and the existing state of EDI training within the workspace. Findings from the context of analysis illustrated that retention in the work force appears not to be affected by gender, with participants overwhelmingly indicating their plan is to continue to work in the timber structural engineering sector. Gender specific findings suggest that most men who practice timber structural design have had more recorded work experience, whereas women were more likely to obtain a PhD when pursuing graduate school.Item Multiscale Analysis of the Flexural Performance of FRP Reinforced Concrete Structures(Canadian Science Publishing, 2024-05-03) bai, hongyu; Yuan, Xin; Gong, ZhengBased on existing experimental data and analysis, seven different FRP bar models including Carbon Fiber Reinforced Polymer (CFRP), Basalt Fiber Reinforced Polymer (BFRP), Aramid Fiber Reinforced Polymer (AFRP), Glass Fiber Reinforced Polymer (GFRP), GFRP and CFRP combined (G-C), GFRP and AFRP combined (G-A), BFRP and CFRP combined (B-C), and BFRP and AFRP combined (B-A) were established. Finite element simulation analysis was conducted on seven different FRP bar combinations under static load bending tests. The flexural behavior of the specimens reinforced with different FRP bar combinations and their influencing factors were analyzed. The results showed that using AFRP as the reinforcement material for FRP composite bars in FRP reinforced concrete beams cannot effectively enhance the overall load-carrying capacity of the composite bars. The combination of CFRP with GFRP and BFRP bars significantly increases the stiffness of the FRP bar structure and improves the structural load-carrying capacity of the concrete beams.Item Modeling HVAC Degradation due to Climate Shocks and Stresses using Dynamic Bayesian Networks(Canadian Science Publishing, 2024-05-20) Ryan, Bona; Bristow, David NThe impact of climate conditions on infrastructure is a major concern for the sustainability of built environment. Two main issues that add uncertainty and complexity in climate change impact are of interest: multiple hazard types and non-stationarity of climate actions. This paper proposes an approach using dynamic Bayesian networks to assess the reliability of a building system considering both gradual and extreme climate factors over the service life of the asset. The methodology is illustrated on a case study that examine an HVAC system, considering overheating fault and degradation risk. Compared to conventional Markov model, the results show stochastic dependence in the degradation process at different time instants and hence affect the variability of degradation. The proposed approach includes economic-based impact analysis to determine costs and payoffs accrued as the consequences. By integrating climate stress and shock and accounting for dynamic changes of the hazard, this method helps decision makers in identifying and prioritizing adaptation strategies for building system under climate change.Item Propriétés physico-chimiques et performances mécaniques de bétons renforcés par des fibres végétales(Canadian Science Publishing, 2024-03-04) Masmoudi, Mounira; Khelifa, Mohamed-Rissel; Hisseine, Ousmane; Metiche, Slimane MS; Masmoudi, RadhouaneCette étude vise à évaluer la capacité des fibres (chanvre et alfa) à améliorer les propriétés mécaniques du béton, dans le but de créer un béton respectueux de l'environnement. Les bétons ont été incorporés avec des teneurs de 0.25 %, 0.5 % et 1% (en volume) en fibres de chanvre, plus une dose de 0.5 % (en volume) de fibres d'alfa et ainsi qu’un béton ordinaire. Les résultats montrent que l'utilisation des fibres de chanvre et d'alfa permet une meilleure augmentation de la résistance à la traction par fendage par rapport au béton ordinaire. De plus, l'augmentation de la résistance à la flexion pour le béton de fibres de chanvre avec une teneur optimale de 0.25%. Aussi, le module d'élasticité dynamique du HFC-0.25 est proche ou égal à celui du béton ordinaire Nous concluons que les fibres végétales de chanvre et d'alfa sont des candidats potentiels pour produire du béton vert.Item Seismic Performance Assessment of Conventional Construction and Ductile Concrete Moment Frames Using Performance-Based Unified Procedure(Canadian Science Publishing, 2024-02-11) Dolati, Abouzar; Fazileh, Farrokh; Fathi-Fazl, Reza; Saatcioglu, Murat; Huang, Xu; Sayed, Mohamed A.A Performance-Based Unified (PBU) procedure has recently been proposed by the National Research Council Canada (NRC) to systematically evaluate seismic design requirements available in the National Building Codes (NBC) of Canada. Conventional Construction reinforced Concrete Moment-resisting Frame (CC-CMF) and Ductile reinforced Concrete Moment-Resisting Frame (D-CMF) systems were used in this paper to first assess the proposed PBU procedure and second determine the adequacy of the basis for seismic design requirements in NBC and see its performance margin against different structural performance levels. Results indicate that the detailed screening in the PBU procedure efficiently reduces the number of Incremental Dynamic Analyses (IDA) by more than 60% for CC-CMF while providing remarkable accuracy. It was also found that the CC-CMF system designed for the Normal importance category can provide an adequate margin against Life Safety (LS) performance level objectives, while the D-CMF system designed for the same importance category passes the Collapse Prevention (CP) performance level criteria.Item Monte Carlo simulation study on the reliability of concrete-filled HSS beam-column design provisions(Canadian Science Publishing, 2024-04-27) Rahbarimanesh, Sadaf; Tousignant, KyleRevisions were recently proposed to the way in which concrete-filled hollow structural section (HSS) members are handled in CSA S16. These revisions were based on previous research, comparisons to experiments, and a first-order reliability method analysis of existing provisions for compression and flexural members. In this paper, this topic is further expanded by using Monte Carlo Simulations (MCS) to determine the inherent reliability of the previous and new design rules for concrete-filled rectangular hollow section (RHS) and circular hollow section (CHS) beam-columns. A representative set of concrete-filled RHS and CHS members with variations in concrete strength, wall slenderness, effective length, and loading eccentricity are analyzed. Using MCS, the reliability index (β+) of each is determined over a range of live-to-dead load (L/D) ratios. Inherent β+ values are compared to the code-specified target (i.e., β+ = 3.0 per Annex B of CSA S16) and the CSA S16:19 and AISC 360-16 provisions.Item Introduction to the Special Issue on Mass Timber Structures(Canadian Science Publishing, 2024-04-27) Woods, Joshua; Doudak, Ghasan; Iqbal, AsifThis paper provides an introduction to the special issue on mass timber structures in the Canadian Journal of Civil EngineeringItem Fire Behaviour of Damaged Wood-Steel-Wood Beam Connections Retrofitted with Self-Tapping Screws – Experimental study(Canadian Science Publishing, 2024-04-27) Hegazi, Mohamed; Salem, Osama (Sam)This experimental study aimed to investigate the structural fire behaviour of damaged glulam beam connections retrofitted using self-tapping screws (STS). Four full-size glulam beam-end bolted connections with wood-steel-wood connection configurations were examined using four or six bolts arranged in two different bolt patterns. All connections were retrofitted using STS after being deliberately damaged through physical testing until failure. In a subsequent stage, the retrofitted connections were experimentally tested under standard fire exposure while subjected to the maximum design load of the weakest, undamaged, unreinforced connection configuration. The influence of the application of STS in terms of preventing wood-splitting propagation and maintaining reasonable fire resistance for the retrofitted connections was experimentally investigated and proven in this study. Results show that the retrofitted glulam beam connections maintained a minimum of approximately 67% of the failure time of identical but undamaged, unreinforced connections under standard fire exposure.Item CRACK DETECTION AND DIMENSIONAL ASSESSMENT USING SMARTPHONE SENSORS AND DEEP LEARNING(Canadian Science Publishing, 2024-03-30) Tello-Gil, Carlos; Jabari, Shabnam; Waugh, Lloyd M.; Masry, Mark; McGinn, JaredThis paper addresses the crucial need for effective crack detection and dimensional assessment in civil infrastructure materials to ensure safety and functionality. It proposes a cost-effective solution for crack detection and dimensional assessment by applying state-of-the-art deep learning on smartphone sensor imagery and positioning data. The proposed methodology integrates 3D data from LiDAR sensors with Mask R-CNN and YOLOv8 object detection networks, for automated crack detection in concrete structures, allowing for accurate measurement of crack dimensions, including length, width, and area. The calculated crack-straight-length closely aligns with the ground-truth straight-length, with an average error of 1.5%. This research has the potential to advance concrete infrastructure inspection, bridge knowledge gaps, and contribute to innovative solutions for precise structural integrity assessment and maintenance.