Automated pavement condition surveys have progressed in the past few years. Mainly developed for superior road network needs, such as highway pavements, they are now very often used in the context of surveys and analysis for municipal network pavements. At this level, quality control of the data is of primary importance to obtain accurate and repeatable results that will allow trend detection and fill the needs of municipal pavement managers.
Profiler surveys to measure road roughness and laser scan technologies to determine cracking and rutting need a focus adapted to municipal networks. Special cases relative to this domain will be presented (acceleration and deceleration areas of survey vehicles, pedestrian crossings with interblock, railway crossings, speed bumps, surface defects related to snow-removal equipment, lateral obstacles and dirty surfaces). In the absence of adequate quality control of the data, each of these special cases introduces inaccurate global indicators for each segment, such as IRI (ASTM E950) and PCI (ASTM D6433).
This paper pinpoints the impact of these special cases in the computed values of the indices. In a few cases, IRI and PCI diverging for as much as 100 % have been noted between data before quality control and after quality control.
From these findings, a few approaches to supervise quality control are introduced for the data treatment phase. These approaches are complimentary to equipment specifications prescribed by municipalities.
Over recent years, several Temporary Steel Barrier systems have been successfully crash tested in accordance with the AASHTO Manual for Assessing Safety Hardware and have demonstrated equivalent and in some cases superior performance to Temporary Concrete Barriers which have been traditionally used in Ontario. Temporary Steel Barriers have gained acceptance in Europe, Australia and other areas of North America and the construction industry in Ontario indicated an interest in using them on Ontario highway construction projects.
In response to this interest and the demonstrated functional equivalence of temporary steel and concrete barriers, the Ministry of Transportation, Ontario (MTO) sought to standardize the use of temporary steel barrier, which required a major re-write of its temporary barrier specification, shifting to the concept of a Temporary Construction Barrier. The Temporary Construction Barrier concept groups both concrete and steel barriers into four categories, based on their Dynamic Deflection when impacted under MASH TL-3 testing, with a corresponding tender item. Contractors are able to select from all systems that qualify for a given tender item. Most steel barriers require pinning into asphalt, and some have been crash tested with different pin spacings, with more frequent pin spacing resulting in a lower dynamic deflection. For three steel barrier systems, standard drawings were created for multiple pin spacing options which correspond to different Temporary Construction Barrier items.
The transition to Temporary Construction Barrier has been well received by the construction industry in Ontario and provides contractors with more flexibility and options for innovation on sites where temporary barrier is required. An added benefit of linking the appropriate tender item with dynamic deflection is higher quality designs as designers are required to consider available space behind barrier to excavations or fixed objects for a staging configuration.
This project involves the analysis and design of a partial Displaced-Left-Turn (DLT) intersection to address road safety and operational concerns at the St. Peters Road intersection on the Trans-Canada Highway in Charlottetown, PEI. As part of this work, PEI Department of Transportation, Infrastructure and Energy analysed numerous intersection improvement and grade separation alternatives, and concluded that an innovative intersection design was necessary.
Although promoted by the FHWA, used by several State DOT’s, and recognized in the 2017 TAC Geometric Design Guide for its operational and safety benefits, the application of this innovative configuration is new to Canada.
In addition to the significant traffic operational improvements resulting from implementing the DLT, safety benefits will also be realized. When compared to a conventional intersection, using the partial DLT reduces conflict points from 32 to 30. This is a reduction of 2 crossing conflicts typically associated with increased collision severity. Pedestrian-vehicle conflicts are also reduced from 24 to 20. Results from before-after studies in the US suggest a 24% reduction in total crashes and a 19% reduction in fatal and injury crashes following installation of the partial DLT.
As the DTL is new to Canada, a cautious approach to the analysis and design was taken. This approach included the application of several analytical methods and tools to assess traffic operations and careful consideration of safety through the use of a senior advisory panel consisting of road safety, human factors and innovative designer experts.
Various DTL intersection design configurations were also observed in operation under a variety of environmental and traffic conditions, and interviews with representatives from several State DOT’s were conducted to glean information for the development of best practices and design elements for application in the Canadian context.
This project is an excellent example of the application of innovative design solutions to address complex design challenges. It provides a valuable suite of Canadian geometric design, signal, signage, and positive guidance best practices for inclusion in future DLT intersection designs in Canada. In addition, it provides valuable insight on a public education program for the introduction of this new intersection configuration.
The Ontario Ministry of Transportation strives to provide a safe, reliable and efficient transportation system to the travelling public. Constructing safe and durable pavement is critical to achieve this mandate.
Ontario has a significant amount of concrete pavement, which includes 849 lane-kms of exposed concrete pavement and 2,187 lane-kms of composite pavement. In 2018, a substantial update to the concrete pavement specification was completed. Significant changes were made to improve the durability of the concrete pavement joints in order to minimize the risk of premature joint deterioration, which can be a safety hazard if the deterioration is severe. Changes to address premature joint deterioration included improved concrete properties and changes to the joint design. The specification implemented the use of longitudinal grooving to replace transverse tinning, which promotes sustainability and safety by reducing hydroplaning and noise levels. Also, the concrete aggregate material specification was updated to increase the insoluble residue content to improve concrete pavement frictional resistance. Furthermore, to improve quality assurance efficiency, smoothness is measured using an Inertial Profiler replacing the use of the California Profilograph.
The changes to the concrete pavement specification are critical to ensure a quality product. To date, a few ministry contracts have been constructed using the updated specification. Details of the specification update and impact to the quality are documented in this paper.
The Saskatchewan Ministry of Highways and Infrastructure (SMHI) recently commissioned a Reclaimed Asphalt Pavement (RAP) Management and Application Study to identify and optimize areas of use for RAP materials. With depleting aggregate sources across areas of the province, RAP is considered a valuable recycled material with surplus quantities generated from construction and maintenance activities across the province’s highway network. RAP materials generated from SMHI contracts typically are either:
made available to contractors to reincorporate in new hot mix asphalt concrete (with an expectation, but no assurance, that bid prices will be lowered to reflect the value of the RAP; or
used as an aggregate substitute within other aspects of the surfacing contract; or
retained by SMHI and stockpiled for future maintenance or construction uses (with fluctuation of inventory levels likely depending on current demand).
One of the outcomes of the study was the generation of a RAP management plan. The RAP management plan was developed by considering current uses of RAP in Saskatchewan at a consultant, contractor, and agency level; and best practices in other jurisdictions. This paper will present the RAP management and re-incorporation processes developed in the form of an optimization table, and decision flowcharts for use during the design, construction, and operations phases of the roadway.
The Province of British Columbia is committed to eliminating serious injuries and fatalities. One way to reach this goal is through increased use of intelligent transportation technologies. The Road Weather Information Systems (RWIS) combined with variable message signs (VMS) are an innovative safety tool that is being rolled out in British Columbia in areas that experience changing road conditions due to weather events.
Weather in B.C. can change rapidly, especially in winter. Adverse weather conditions create an environment in which it is difficult for drivers to navigate safely. RWIS can be utilized to provide travelers with information on current weather and road conditions via electronic variable message signs and reduce the frequency and severity of winter collisions.
The Ministry of Transportation and Infrastructure has combined RWISs and VMSs at seven locations on rural highways that experience extreme winter weather conditions and a poor safety performance. Each system comprises of a RWIS connected to two VMSs, one in each travel direction. The RWIS system automatically analyzes weather and road conditions every 15 minutes and an algorithm selects an appropriate sign message to provide real time information to the road users.
The safety benefits for implementing a RWIS/VMS were evident with an overall reduction of over 30% in severe winter collisions. The benefits of implementing a RWIS/VMS exceeded the cost, with an overall benefit-cost ratio of 4.8. This indicates that the implementation of RWIS/VMS in British Columbia was an effective investment in improving highway safety.
Based on the success of the RWIS/VMS systems in BC, the Ministry has expanded the program to include other ITS technology, such as the LED equipped static signs to alert motorists to specific road conditions, such as the fog warning or icy road sections. The Ministry is continuing to monitor the benefits of the RWIS expansion on our highways but have observed a reduction in serious collisions on the segments where they have been deployed.
General use limestone (GUL) cement is now permitted in the production of all classes of concrete in Canada. Its contribution to reduction in greenhouse gas emissions and sustainable construction is the main driving force for its development globally. However, there has been dearth of information on the effect of GUL on performance of concrete exposed to high concentration of chloride-based salts. Therefore, the aim of this study is to investigate the response, in terms of physico-mechanical properties and microstructural features, of concrete made with GUL without or with fly ash to highly concentrated chloride solutions (NaCl, MgCl2 and CaCl2). A continuous immersion exposure at 5°C was used to promote formation of complex salts (oxychlorides). The results revealed that GUL mixtures exhibited better resistance to de-icing salts due to synergistic physical and chemical actions of limestone in the cementitious matrix. The resistance of concrete exposed to de-icing salts is a function of physical penetrability (magnitude of intruding solution), amount of aluminate in cement and content of portlandite available for chemical reactions in the hydrated paste. The incorporation of high volume fly ash (30%) had a pronounced effect on improving the concrete resistance to damage as reflected by sound mechanical properties and longevity.
Rail transportation systems are increasingly relying on information and communications technologies. Modern industrial control systems which are based on the new communications technologies have replaced the traditional mainframes and obscure protocols which were formerly the backbone of the industry. The cited evolution, however, has enabled a new level of vulnerability through external connectivity, which introduces new risks to public safety and continuous operation of mission critical services. As a means for risk mitigation, cybersecurity has gained an unprecedented level of attention and importance in the context of mission-critical services, in addition to the traditional focus on reliability, availability, maintainability, and safety.
In the presented article, the cybersecurity state of affairs for rail transportation systems is investigated and complex security engineering challenges in these mission-critical cyber-physical systems are addressed. The subject of cybersecurity in rail transportation is looked upon from an enterprise-wide point of view, instead of the traditional IT/technological angle. As a result, after a detailed elaboration of the threat vectors and vulnerability scenarios, an interdisciplinary array of mitigation approaches (countermeasures/safeguards) are proposed which are based upon a complete alignment of business aspects and include a multi-front strategy of prevention and recovery-based mitigation through improving system resilience.
It is with increasing frequency that agencies are faced with the impact utility cut installations have on their roadway networks. Excessive utility cuts in pavements are known to cause premature deterioration, pavement weakening, excessive road roughness for the pavement structures, and decrease of pavement asset values. In 2018 the City of Saskatoon (the City) with the assistance of Tetra Tech Canada Inc. (Tetra Tech) completed a study to demonstrate the difference in pavement performance resulting from the presence of utility cuts between 2014 and 2017 on the City’s roadway network.
First, roadway condition data (International Roughness Index (IRI) and Pavement Condition Index (PCI)) were assessed for sections with and without utility cuts installed between 2014 and 2017. The features and patterns in the change of IRI and PCI are explored for each City roadway class. Significant differences in reported IRI and PCI were found between pavement with and without utility cuts. Second, the characteristics of utility cuts including the size of the cuts, pavement age, and the IRI and PCI when the cuts were conducted were analyzed. The resultant costs relative to the loss in service life over the pavement life-cycle were determined. Based on pre-utility cut condition instead of pavement age, the pavement performance impacts and potential loss of service resulting from utility cuts were assessed. Finally, linear regression models of IRI and PCI were determined for each roadway class with and without utility cuts. IRI and PCI deterioration curves were developed to evaluate the expenses for utility cuts, loss of service life, pavement rehabilitation cost. Asset value impact matrix were proposed for each roadway class.
It is found that the impacts of utility cuts can be quantified, and an associated reduction in roadway asset value and pavement serviceability can be calculated. The information in this study may ultimately be used by the City to assist in determining the costs associated with the utility cuts on their roadway pavement network, and in quantifying the impact of utility cuts on pavement serviceability and the typical loss in pavement asset value.
Permeable pavements are becoming popular in North America especially in the last decade. Permeable pavements are considered as a low impact design and beneficial for best stormwater management practice. Porous Rubber Pavement (PRP) is a comparatively new addition to this type of pavements. PRPs are currently utilized on low traffic roads and pedestrian walkways as surface material. PRPs use as a surface wearing coarse for abating the road noise has been found in few European and Asian countries. The constituents of PRPs are stone aggregates, crumb rubber from recycled tyres, and polyurethane as the binder. As a new pavement material in North America, its performance has not yet been assessed for this climatic condition. Because of its higher permeability (27% to 29% of voids), this material can be highly beneficial for preventing hydroplaning, glare, spray and splash on the road surface during surface runoff. Also, as a result of its flexible nature, it has de-icing capability by deformation of ice on its surface layers. Field pavement performance evaluation was conducted on a parking lot located in Ontario, Canada where PRP was used as surface material. This paper presents some results obtained during these investigations with focus on surface roughness, permeability and surface distress of PRP pavements. Two equipment; SurPRO and Dipstick were employed to investigate pavement roughness in terms of International Roughness Index (IRI). The average IRI of the PRP surface was found to be 10 m/km. The average infiltration rate was found to be 30,836 mm/h. Ravelling (disintegration of material from the surface) was found to be the major surface distress during distress evaluation. Though the PRPs show widespread benefits, there is an opportunity to improve its performance after thorough evaluation, which can make this material a good candidate for the low impact pavement surface. This investigation can be the basis for the future improvement of this material.
Increasingly local and regional municipalities are constructing bicycle facilities within the boulevard, whether they be dedicated bicycle lanes or multi-use pathways (MUP’s). In addition, cyclists also often use sidewalks. Cyclists can travel up to 20 km/h and where these cycling facilities cross non-signalized driveways and local roads there is a significant potential for conflict between cyclists and exiting drivers, especially considering that many drivers are “non-compliant” and do not always stop in advance of the cycling facility. Therefore such “non-compliant” drivers and cyclists should have enough sight distance to allow them time to observe, initiate and execute the desired actions to avoid a collision. This paper will show that there cannot be a “one size fit all” solution because sight distance requirements are a function of several variables that can differ from location to location. The most critical variable being how far the facility is located from the curb. It is therefore imperative that required sight triangle dimensions be calculated on a site by site basis. The paper will develop and present the mathematical models and tools that can be used to calculate the sight triangle dimensions for any location – for both “compliant” and “non-compliant” drivers. From an infrastructure design perspective it will increase our understanding on how modifying certain cycling facility design parameters will impact sight triangle dimensions – and hence how we can reduce the risk of conflict between drivers and cyclists. From a land development perspective the models and tools will assist planners and engineers to determine the size of daylight triangle areas that should be kept free and clear of any potential sight line obstructions. when and what type of mitigating measures may be required to reduce conflicts. The TAC Guidelines provides no guidance on sight distance requirements between driveway vehicles and cyclists on cycling facilities. The research aims to fill this gap by using a first principle based approach towards developing guidelines and tools we can use to minimize conflicts between vehicles and cyclists.
Nanaimo has been developing its Complete Street Design Guideline while in parallel putting it into practice on the Metral Drive corridor, showcasing sustainable urban transportation design in the City. The guidelines set a high bar for all future street design, reallocating the right-of-way in an equitable manner and managing conflicts safely.
The immediate implementation of the guidelines on Metral Drive will demonstrate how such designs can contribute to community wellbeing by providing a safe environment that enables people to choose active and healthier travel options while also enhancing the streetscape. Metral Drive currently has varying levels of pedestrian provision from sidewalks to gravel shoulders and no cycling provisions. The inconsistencies are not conducive to attracting people out of their cars. Using the guidelines to develop the Metral Drive detailed design, the City will provide people, regardless of their age, income or physical ability, with safe travel options to the Woodgrove Centre, one of Nanaimo’s key mobility and economic hubs. While the guideline recommends best practice levels of space and separation, it also includes retrofit guidance and speaks to how similar outcomes can be achieved for lower costs or in constrained rights of way.
The guideline and Metral Drive design include many best practices, but most innovative is the adoption of Dutch design principles prioritizing active modes through design with continuous sidewalks and bike paths across local roads. While this old design technique is often used in Europe, we believe it has not been fully implemented in Canada.
To understand the value this would add to the Canadian context and confirm our belief that this technique has not been widely adopted, the team queried many well-respected planners, engineers, and advocates through twitter to try and find examples of such designs. It revealed nobody in Canada appears to be adopting such designs and Nanaimo aims to change that! Metral Drive will provide a Canadian showcase for Dutch-style intersections in Canada prioritizing the safety of our most vulnerable and will position Nanaimo as an example of best practice for all communities in Canada to reference.
Developing a risk-informed decision making framework is crucial to address two major aspects of managing road networks. The first is the development of deterioration models to capture physical deterioration trends based on various road attribute combinations. The second is the development of an optimization process for capital planning that integrates lifecycle cost analysis, risk analysis, effectiveness of maintenance and rehabilitation technologies, network effects, cross-sectoral interactions, and strategies for asset inspection with dynamic model updating. This session discusses techniques for performance modeling and risk-informed decision making methods with a focus on municipal pavement assets. Canadian municipal case studies are presented to show the effectiveness of the methods presented and to discuss real-life implications.
Moisture-induced damage is among the four prevalent causes of premature failure of flexible pavements in Canada. Research on moisture damage evaluation of asphalt concrete mixtures dates back to approximately one century ago. However, relating the field performance of mixes to their associated properties captured through laboratory test methods is not fully developed yet. Several test methods have been utilized over the last few decades to assess the moisture-induced damage of mixes in the laboratory scale. Studying the Tensile Strength Ratio (TSR) or loss of indirect tensile strength (ITS) due to moisture conditioning of specimens with or without (a) freeze-thaw cycle(s) has been the most commonly used method in North America. Review of case studies indicates major shortcomings of this technique. For instance, in many cases a mix may pass the minimum TSR requirements in the laboratory, but would fail in the field and vice-versa. Therefore, many transportation agencies have been recently investing in finding alternative test methods such as Hamburg Wheel-Tracking Test (HWTT) and Moisture-induced stress tester (MiST) to better predict the moisture-related performance of flexible pavements. This study, provides a critical review of the existing methods for evaluation of moisture damage in asphalt mixtures along with their strengths and weaknesses for this purpose. The major parameters that contribute to this complex phenomenon are also discussed. A synthesis of the state of practice for design specifications and materials acceptance with respect to moisture damage by different agencies is also provided. Finally, the need to use domestically calibrated moisture conditioning, evaluation practices, and establishing customized acceptance thresholds that suit the climatic conditions in Canadian environment is highlighted. Recommendations are provided for an improved moisture damage assessment framework, based on the lessons learned from the past experiences as well as the identified promising techniques.
Concrete roads crack and deteriorate due to severe service loadings, de-icing materials, freeze-thaw cycles, etc. The replacement cost of existing deficient concrete roads is expensive. Moreover, the design of maintenance materials requires the use of energy-efficient materials with a low environmental impact. Facca Incorporated, in collaboration with Dura Concrete Canada Inc., located in Ontario has been developing an innovative cementitious composite for different construction applications. One of these applications is the use of Ultra-High-Performance Concrete (UHPC) and Engineered Cementitious Composites (ECC) as a partial patch repair for concrete roads. The mechanical and durability performance of UHPC and ECC mixtures were investigated. The mechanical performance of the mixtures was assessed by means of compressive, and flexural strength. While, the durability of the mixtures was investigated and evaluated by the means of rapid chloride penetration, absorption, and plastic shrinkage. To compare the mixture's performance in the field, a location in the City of Windsor was selected. These innovative in-situ repair materials were applied in thickness varying from 40 to 60 mm. The selected road was closed, milled, prepared, repair materials applied and completed within 24 hours. The strength gain in 24 hours of both UHPC and ECC were acceptable to open the roads to traffic after 48 hours. Laboratory and in-field results and observations for the road repair materials, showed superior mechanical and durability characteristics.
The City of Guelph has opened an industry leading new parking garage powered entirely by renewable energy sources, making it Guelph’s first energy self-sufficient and self-sustaining parking facility. Supporting the City of Guelph’s commitment to its corporate 100RE target through which all City facilities and operations will use 100 per cent renewable energy by 2050, the new garage has 496 stalls, EV charging, accessible stalls and secure bicycle parking. The facility is a Net Zero Energy site with over five hundred solar panels installed on the roof, generating nearly 200,000 kWh/year.
As the first parking garage built in the City of Guelph in over thirty years, the new Market Parkade is positioned to address the emerging issues posed by climate change by depending entirely on renewable energy sources to power its EV charging stations, lights, security and parking access and revenue control equipment. The facility starts with four EV charging stations and has the infrastructure to expand to eighty EV charging stations as consumers’ usage patterns change. Moreover, the facility was built using the CANADACAR Parking Structure System: a pre-engineered, prefabricated building system that utilizes the most advanced, innovative technique of construction resulting in free span modular parking bays. The CANADACAR Parking Structure System offers the following benefits: cost efficient, reduced maintenance costs, driver/pedestrian safe, reduced construction time, increased longevity, greater flexibility and increased volume, all components in reducing the initial and ongoing carbon footprint of the facility and its operation.
The facility was built with a view to the lifecycle cost to maintain the structure. Importantly, the facility was built as the first step in realizing the City of Guelph’s goal of using only 100% renewable energy sources by 2050. The new garage will produce significant cost savings in its ongoing operation and maintenance. From an energy perspective, the facility has a 188kW electrical generation capacity expected to produce 200,000 kWh/year from renewable energy sources. The electricity produced will meet the needs of the facility as well as the annual electricity required to power the four EV charging stations. The City will return any excess electricity to the grid for use in other facilities. This self-sufficiency will save ~$35,000 annually in operating expenses alone.
Project achievements were:
Eliminating all four expansion joints using innovative link slab and semi-integral abutment details. To our knowledge the link slabs are the rst that used hooked steel bres in an exposed concrete deck in Saskatchewan/Alberta. The link slabs are performing well after 3 years in-service;
The service life of the 56-year old structure was extended by 40+ years and reduced the carbon footprint of the bridge by salvaging most bridge elements.
Leaking water through bridge deck expansion joints is one of the leading causes for bridge deterioration and results in high priority, costly, and challenging repairs to the bridge elements below them. Using life cycle cost analysis, semi-integral abutments and link slabs at the piers were the most practical and cost-effective solutions.
Although many jurisdictions utilize semi-integral abutments to eliminate abutment joints, the use of link slabs to eliminate pier joints does not share the same popularity. Although the link slab concept is not new, a lack of historical performance data has made some bridge owners reluctant to use this concept. Through our extensive research and careful design, we encouraged the client to proceed with link slabs.
In additional to the semi-integral abutment conversion and link slab installation, the following repairs were also completed:
Partial depth deck rehabilitation and deck widening;
Girder strengthening to support new standard design vehicles
Upgraded bridge and approach railings to current standards; and
Lifted superstructure to facilitate substructure repairs and a bearing replacement.
Some of the unique, challenging, innovative, environmental, and sustainable achievements on this project were:
Eliminating all expansion joints using innovative link slab details. To our knowledge, these are the first link slabs that have used hooked fibre reinforced concrete in the exposed concrete deck. These details will significantly improve the exposure condition of the underlying elements from chlorides and moisture. This will extend the service life of the bridge and reduce future costs. After being in-service for three-years, the link slabs are performing well with no visible signs of leakage.
Extending the service life of a 56-year old structure by 40+ years;
Reducing the carbon footprint of the bridge by salvaging most of a 56-year old structure rather than disposing of it and fabricating new bridge elements. The existing elements were repaired, modified, or strengthened to improve their condition, functionality, and service life.
Environmental DNA is an innovative method to collect accurate data is needed to predict presence of species at risk and other species that use aquatic habitats for impact assessment, meet regulatory requirements and identify specific mitigation to address potential adverse effects. This method is particularly suited to linear transportation projects which typically cross or impact multiple waterbodies.
In British Columbia, federal and provincial guidance require stringent sampling methods to demonstrate presence / absence of species at risk. Trapping and other direct sampling methods can have significant impacts on the target species (e.g., mortality). As organisms shed deoxyribonucleic acid (DNA) in aquatic environments, eDNA samples can be collected from these environments. Studies of eDNA have gained scientific and regulatory acceptance in recent years, especially for surveying at-risk aquatic and semi-aquatic species. Benefits of this type of sampling include: Lower costs - eDNA field sampling requires only the collection of water samples, avoiding complex multi-day conventional sampling programs (e.g., baited trapping, electro-shocking and/or physical searches. Once baseline primer development is complete, costs can be 10% or less of conventional
methods. Non-invasive – avoids mortality risk due to physical injury or pathogen transfer associated with conventional methods Highly accurate – eDNA sampling when correctly implemented, is definitive for detection of presence and very sensitive to detection of aquatic species;
The credibility of eDNA survey data, however, depends on adequate methodological validation and verification; accurate results require rigour during field sampling, sample processing, laboratory analysis, and primer design and/or verification. Hemmera recently developed accepted standards for collection of eDNA for the BC Ministry of Environment and has completed for multiple transportation projects including MOTI’s South Fraser Perimeter Road (target species - red-legged frog and Pacific water shrew), MOTI’s Kicking Horse Canyon Phase 4 (target species Western toad) and TransLink’s Surrey Langley SkyTrain project (target species – multiple salmonids, Pacific water shrew and red-legged frog).
In cold regions, asphalt concrete (AC) pavements experience freeze-thaw (F-T) cycles. F-T cycles can cause damage and disintegration of AC mixtures, which cause significant operational problems and a reduction in the service life of AC pavements. The evolution of the internal structure of an AC mix due to exposure to F-T cycles should be explored to have a better understanding of the mechanism of F-T damage in the mix. In this study, different AC specimens were evaluated before and after F-T cycles using two techniques: indirect tension test (IDT) to evaluate strength deterioration of specimens, and imaging techniques to capture changes in the internal structure of specimens. Three imaging techniques were used in this project: digital camera, stereomicroscope, and X-ray computer tomography (CT) scan system. Each technique has its potentials to show the internal damage details. AC specimens have been assessed at different levels of F-T cycles. 2D and 3D images for the internal structure of the specimens were collected and analyzed at 0, 15, 30 and 45 F-T cycles. The captured images will be analyzed to quantify the F-T damage according to adhesion failure (%), cohesion failure (%), broken aggregate (%), and the total length of microcracks (mm). The results from image analysis will be correlated to IDT results.
It’s well known that using a variety of instructional methods increases participants’ retention of the content and their enjoyment of the course. Videos are a good way to appeal to visual and auditory learners, with the added appeal that the content is always consistently delivered as intended.
After 25 years of using the same Bridge Inspection & Maintenance instructional video in OGRA’s Bridge & Culvert Management Course, the video was dated. To create a top-quality, technically accurate product, OGRA recruited assistance from industry subject matter experts who teach for OGRA and are leaders at their organizations – 407 ETR, GHD, and the Town of Innisfil.
Thanks to these experts, the content was reviewed to ensure technical accuracy and consistency with the Ontario Structure Inspection Manual. Of equal importance to our students, the minutiae of the content were reviewed and debated at length to ensure the information is practical and can realistically be employed when they return to their organization. More importantly, the shots were all updated to demonstrate the best safety practices to reinforce the important role safety plays in all our activities.
In planning the video, we included relevant technology that should be used, such as mobile devices. Thanks to our subject matter experts and their generous employers, we were able to include current practices and equipment such as a Bridgemaster truck.
To appeal to visual learners, we used a high-resolution camera. To get unique shots at interesting angles, a drone was employed. The animations have been updated to make them realistic and better show key concepts. For auditory learners, we used technology which provided crisp sound without distracting background noise.
In reviewing the old video, it was quickly noted the people shown in the video do not represent today’s diverse workforce. To rectify this, both a female and male host were used to present information and for voice-overs. When filming bridge inspection or maintenance, we ensured a variety of people were used, who are all currently involved in the infrastructure industry.
Merci à nos commanditaires premier
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