A 1500 MHz Ground Penetrating Radar (GPR) survey was conducted on the Beaver River Bridge, located near Dapp AB. The bridge deck had previously been identified as being partially testable with regards to Alberta Transportation Level 2 Copper Sulphate Electrode (CSE) half-cell potential testing due to problems with the western pre-cast prestressed RD box girder span. The deck also included an overhead through-truss (TH) span with a concrete deck that was constructed using galvanized reinforcing steel. After adjustment to account for higher chloride concentrations required for corrosion initiation of galvanized steel versus uncoated steel, areas of elevated GPR signal attenuation were thresholded correlated closely with areas of CSE values more negative than -400 mV in the TH span. Areas of elevated GPR signal attenuation levels, assumed to be caused by increased chloride content in the concrete cover layer, correlated closely with CSE values more negative than -400 mV on the TH deck span, and with areas where cracking and corrosion staining were observed in all spans. The GPR results were effective in describing areas of longitudinal cracking in the RD spans along the grout keys which appeared to be impacted by high levels of chloride ingress. The GPR also indicated low but elevated levels of chloride ingress along multiple transverse cracks observed in all of the TH span panels. Level 2 CSE testing was not able to identify either of these issues. Both the CSE and GPR results indicated that the majority of the deck appeared to have a low risk of corrosion in most areas that were not cracked. After adjustment to account for higher chloride concentrations required for corrosion initiation of galvanized steel versus uncoated steel, the GPR results indicated that conditions for corrosion were unlikely at two locations where reinforcement had been previously exposed for inspection due to CSE values that were indicative of corrosion activity. GPR survey results can provide transportation agencies with a rapid and accurate means to quickly gather important parameters related to monitoring the condition and service life prediction of their reinforced concrete deck infrastructure or for quality assurance purposes for new construction or rehabilitation.
The Saskatchewan Ministry of Highways and Infrastructure (SMHI) adopted Laser Crack Measuring System (LCMS) technology for collecting road condition data in 2016. LCMS data has replaced a visual assessment method for identifying cracking and other surface distresses. This paper discusses the methodology used to determine type, severity, extent and aggregation of LCMS distress data. To better analyze the data, SMHI developed the Surface Condition Indicator (SCI) to support asset management decision making for setting performance measures, optimize budgets, and identify pavement preservation candidates. The paper covers: The use of LCMS generated crack maps and a Bayesian sorting methodology to develop severity ranges for pavement distresses. The methodology used to identify the type and severity of LCMS measured distresses that map to treatment triggers for rejuvenating fog seals (CRF™ and Reclamite™), graded aggregate seal coat, chip seal, fiber-reinforced chip seal, microsurfacing rut fill with a seal coat cape, and functional repaving. The methodology for setting the SCI threshold values (Good to Fair and Fair to Poor). The development of SCI formulas for Asphalt Concrete and Granular Pavements. The process of calibrating SCI values with field observations and “blind” testing the SCI numbers in the field to confirm results for the SCI metric. The benefits of adopting the SCI for finding good pavement preservation candidates and ruling out locations that are too late for fog or seal coat treatments. The benefits of adopting the SCI for setting performance measures and communicating trade-offs in investing for pavement preservation projects. SMHI’s SCI values range from 0 through 100+ in a progression that reflects the amount and severity of pickouts and cracking that develops as pavements age. SCI60 values are categorized as good, fair or poor. Pavement segments with fair SCI60 are light treatment preservation candidates. Pavement segments in the poor category are too late for a light preservation treatment. SCI60 values over 45 require a heavy preservation treatment.
Transportation 2040 and the Greenest City 2020 Action Plan identify that a mode shift toward walking, cycling, and transit is critical to accommodate regional population growth and to meet our environmental targets. The recent Burrard Bridge project addresses a major gap in the walking network by once again allowing walking on both sides of the bridge. In addition, the proposal greatly improves comfort, convenience, and safety for people walking and cycling across the bridge by upgrading the Burrard and Pacific intersection and providing new or improved connections to the existing walking and biking networks, all while ensuring that transit and good movement are not compromised. To retain the existing tree canopy, most trees were preserved, including a large Cypress tree that was likely planted shortly after the opening of the bridge in 1932. Over 60 new trees will be planted at the intersection and surrounding blocks. The project represents a bold initiative to create a Green Transportation solution: creating safe and comfortable walking and cycling routes by reallocating road space in a dense urban environment while supporting current trips over the bridge and respecting the heritage value of the Burrard Street Bridge.
Burrard Bridge is one of three City-owned bridges that cross False Creek, a body of water separating the high-density downtown core and medium-density neighbourhoods to the south. The bridge was opened in 1932 as a six-lane vehicular bridge with sidewalks on both sides. The bridge was built in the Art Deco style and City Council included it on the City's Heritage Register in 1986. Over the years, the City has completed a series of rehabilitation projects and upgrades to keep the bridge safe and functional. The role of the bridge has evolved over the years, primarily in response to accommodating a growing number of cyclists using the bridge. Prior to 2009, people walking and cycling shared the sidewalks on both sides of the bridge. As the number of people crossing the bridge using active transportation grew, the shared sidewalk became increasingly hazardous for pedestrians and cyclists. Safety was a particular issue for people cycling, as they were directed to ride in a narrow area adjacent to motor vehicle traffic and a minor error (or conflict with a pedestrian) could cause them to fall off the sidewalk onto the roadway. In 2009, the City reallocated a southbound travel lane from general purpose traffic and prohibited pedestrians from using the east sidewalk in order to create a protected bicycle lane in each direction (refer to Appendix). Since then, walking and cycling volumes have increased significantly with cycling growing by over 30%. The Transportation 2040 Plan, adopted by Council in 2012, includes a zero transportation related fatality goal and identifies the False Creek Bridges as an area of focus for active transportation improvements to address gaps in the pedestrian and cycling networks. Burrard Bridge is one of the busiest active transportation corridors in the city, with 10,000 walking and cycling trips on a busy summer day. It also carries approximately 55,000 motor vehicles, 13,000 transit passengers, and 500 trucks on a typical day.
This paper presents best practice guidelines and strategies for harmonizing provincial and municipal highway construction standards and specifications in Manitoba. Developing common construction standards with stakeholders of diverging goals can be challenging, but beneficial. The adoption of a consistent set of standards and specifications in a jurisdiction could minimize redundancy, identify critical requirements that need to be retained to maintain performance, cut construction and compliance costs, simplify the process of meeting requirements, and reduce complexity for those that are tasked with testing and standard compliance. Therefore in this study, a survey questionnaire was developed and sent to the provincial and municipal highway agencies, contractors, aggregate producers, and testing labs in Manitoba. The purpose of the survey questionnaire was to obtain input on harmonizing provincial and municipal specifications and standards for asphalt, concrete, granular base and rip-rap, and grading roadway projects. The survey questions focused on identifying key issues of harmonization including barriers to change, benefits, trade-offs, common goals, potential risks, cost-effectiveness, and quality control and quality assurance delivery mechanisms. The results of the survey recommendations for harmonizing standards and specifications are presented. The recommendations can be used by highway agencies to quickly implement the best practices, thereby realizing the benefits of harmonizing standards and specifications in their jurisdictions.
This report examines the use of the asphalt ignition oven temperature-time series generated during the asphalt content by ignition test method in identifying erroneous test results. The study was undertaken to provide an empirical tool for asphalt laboratory staff in troubleshooting and validating asphalt content test results. Results of the data analysis show that some variations in testing procedure can be identified through the temperature-time series. In particular, the first tests performed each day are readily discernable from subsequent tests, even after allowing significant oven warm-up time. Variations in sample size or asphalt content are also shown to create differing temperature-time series; however, the difference is not significant enough to identify errors on individual tests, it is only demonstrable across the group averages. Despite the differences in temperature-time data, no conclusive difference in the accuracy of the test results was found. It is concluded that the monitoring of the temperature-time series may be a valuable tool in identifying systematic and gross errors introduced during the asphalt content by ignition test method. However, while the preliminary results of this study demonstrate that differences do exist, additional testing should be undertaken to assess the reliability of the proposed method under real-world scenarios. Additional trials will also be required to identify any other procedural variations which result in differences in the temperature-time trend.
Armstrong Avenue in Georgetown Ontario is one of the Town’s industrial hub’s within Halton Hills. In 2013, the Town of Halton Hills initiated the process to reconstruct Armstrong Avenue with a forecast construction date of 2017-2019. The project was broken into two phases. Phase 1 (approx. 1310m) and Phase 2 (approx. 1310m) (Appendix A). Through an Ontario Municipal Class Environmental Assessment study it was identified as a section of road in need of active transportation and improved traffic operations to service the multiple industrial/commercial businesses (approx. 115) (Appendix B). In 2013, the Town of Halton Hills developed a Community Sustainability Strategy (Strategy) where the four pillars of sustainability: cultural vibrancy, economic prosperity, environmental health and social wellbeing, were identified and are recognized in the all of the Town’s work including Armstrong Avenue Reconstruction - Phase 1 project.
In some transportation agencies including the Florida Department of Transportation (FDOT) use Open Graded Friction Course (OGFC) mixture to improve skid resistance of asphalt pavements under wet weather. FDOT designs OGFC mixtures using a pie plate visual draindown method FM5-588, which depends on the Optimum Binder Content (OBC) and represents if the mixture has sufficient bonding between the aggregate and asphalt binder, otherwise known as the asphalt binder draindown (ABD). In the FM5-588 the OBC is determined based on visual inspection by trained and experienced technicians. In order to eliminate the human subjectivity involved in aforesaid method, an artificial intelligence (AI) methodology for prediction of the OBC using digital images of the test specimens, perceptual image coding and General Regression Neural Network was created. Then, the author developed a quality control tool (QCT) for the aforementioned AI method to enhance its reliability when implemented by other agencies and contractors. QCT is developed using three quality control imaging parameters of ABD of the test specimen images. In general, this study found that the newly developed AI software provides satisfactory and reliable estimations of OBC and that the QCT will enhance the reliability and accuracy of the AI OBC estimation software.
Saskatchewan’s Ministry of Highway and Infrastructure (MHI) has a highway vehicle weight management system to maximize highway infrastructure utilization for economic activities while protecting highways to ensure a longer service life. The provincial highway system is generally managed in three allowed vehicle weight categories: i) Primary highways with year round access, ii) secondary highways that are weight restricted during early spring, and iii) nine-month primary highways that allow primary weight for 9 months and secondary weight for the remaining three spring months. The categories were established according to highway pavements’ structure capability to handle vehicle weight. The weight restriction on secondary and nine-month primary highways is mainly to protect these lower standard pavements from spring-thaw damage. The secondary highways are subject to the spring weight restriction based on weather triggers (thermistor data). However, to allow for planning freight operations, the nine-month primary follows a fixed schedule where the weight is reverted to secondary for three spring months every year. MHI conducted a study to evaluate if the timing of the three-month secondary weight reversion for nine-month primary highways could be changed to align better with early spring-thaw period. Extensive analysis of historical temperature data, historical spring weight restriction dates, and Benkelman Beam Deflection data from various locations in the province was conducted. The study concluded that due to the different geographical and climatic conditions in the province, highways in the south of the province are more vulnerable from early spring-thaw than those in the north. While the current timing of the three-month secondary weight reversion for nine-month primary highways creates an unacceptable risk for highways in the south, they were found adequate for highways in the north. As a result, a new policy has implemented the secondary weight reversion 15 days earlier for nine-month primary highways in the south than in the north.
Government agencies such as municipalities own several lane kilometers of roadways all in varying conditions depending on their traffic loads, environment, material types, and construction methods. Managing a vast inventory of assets can be challenging and depending on the size of the municipality, sufficient resources may not always be present for municipalities to accurately understand their networks’ needs. Size of municipalities notwithstanding, funding to maintain these networks always remains a challenge. Finite funds are constantly competing against other priority infrastructure as well as politically motivated projects being broadcasted the loudest. Moreover, not all networks are created equal; some networks may be more rural and require different treatment and maintenance needs compared to an exclusively urban environment. Understanding all these parameters is critical in order to grasp the complexities and challenges that Alberta municipalities and agencies face when maintaining their transportation networks. To determine these answers, a questionnaire survey was conducted to the Pavement Management Users Group in Alberta. The results showed several consistencies related to the use of traditional pavement treatment methods, such as mill, overlay, and conventional reconstruction. This study noted, however, that there exists a gap in the use of preservation methods, such as microsurfacing, being used around the province of Alberta, as well as staff resource and asset management challenges. This survey provides a unique insight into the treatment selections and resources dedicated to roadways and strategies around the province.
In over 50 years since the invention of Reinforced Earth walls, structures have been designed to fulfill a variety of retaining solutions for infrastructure projects, as well as mining, marine, industrial, commercial and residential projects. Over the service life of these projects, owners may decide to change the scope of structures. These changes may include: design life extension, wall height increase and other alterations in geometry, changes in loading configuration, etc. To accommodate these modifications, structures must be assessed based on new scope, in addition to incorporating design changes. This paper will present an inspection and evaluations program though a case study where specific assessment methods and techniques have been utilized to demonstrate whether Mechanically Stabilized Earth (MSE) walls can be stable for the required changes in scope. The assessment method includes visual inspections, strip sample extractions, and corrosion assessment. Since the service life of the structure is dependent on the strength of the soil reinforcements, by evaluating the strength of the test samples, the stability and remaining design life of structures at the current state can be determined. Following a similar method, the stability of a structure can be evaluated if loading conditions or geometry configurations need to be changed over the remaining structure’s design life.
As a demonstration project of the Pedestrian Strategy, The City of Calgary collaborated with students from Langevin School, the University of Calgary’s Landscape Architecture program, the Bridgeland Riverside Community Association (BRCA), Calgary Drop-In Centre and other stakeholders to imagine how the space beneath the 4 Avenue flyover could become a valued community space and walking corridor. The project involves piloting innovative technical measures (transportation, art and bioretention) and non-traditional engagement and design approaches under the umbrella of placemaking and tactical urbanism.
Pavement structures costs constitute to the majority of the total costs of highway construction projects. Therefore, it is important to optimize each pavement structure to avoid an under-deign or overspending on any project. In the past, Manitoba was using the Benkelman Beam Rebound (BBR) deflection method for the rehabilitation design. A mixed approach, together with several environmental and structural adjustments, was used in pavement design for the new construction or reconstruction projects. The assumed or estimated values of subgrade and layer materials stiffness did not well represented the materials those are in place or use in Manitoba. These led to an overdesign for most rehabilitation and some new construction projects. Due to several limitations of the AASHTOWare Pavement ME Design approach, that yet to be resolved, Manitoba has undertaken major changes to its existing design practices for cost-effective pavement structures. These include the use of more reliable/reasonable design traffic loading, layer materials and subgrade stiffness and drainage properties, pavement drainage condition, subgrade soils frost susceptibility, serviceability and reliability. As a result, significant cost savings are being realized. This paper presents an overview of Manitoba’s new approach and outcome to share with other agencies, designers and students.
Originally built in 1907, the Traffic Bridge was Saskatoon’s first bridge to carry vehicular traffic. The Traffic Bridge was designed as a 5-span Parker through truss and came into being when residents of the Village of Nutana agreed to merge with the Town of Saskatoon and the Village of Riversdale to form the City of Saskatoon. The heritage value of the Traffic Bridge lies in its status as a landmark in the community, its form, massing, and location, the engineering technology used (steel truss architecture), and the original concrete piers and abutments. Throughout its 103-year history, the bridge has been used for horse and carriage, street car, and modern vehicle use. The bridge also has historical notoriety as Saskatoon’s only marine disaster when the sternwheeler S.S. City of Medicine Hat collided broadside into the southern-most pier of the bridge and sank on June 10, 1908. The bridge was closed in August 2010 due to public safety concerns due to advanced deterioration of critical structural members. In 2010, the City commissioned a needs assessment and planning study of the Traffic Bridge, which investigated multiple alternatives and potential replacement, included extensive public consultation, regulatory review and debate, as well as City Council presentations. Many elements of the existing bridge were to be incorporated into the new bridge. Engineering studies were completed on the existing elements to determine strengths and compatibility with the new structure. A P3 model was used for the design and construction of the replacement bridge. Many challenges presented themselves during the design and construction of the structure and these challenges provided unique resolutions. The bridge is currently under construction, and upon completion, the contractor will be responsible for the maintenance of the bridge for the next 30 years.
The Bonaventure Project is a series of strategic undertakings aimed at providing user-friendly, functional and safe mobility options to all users. The Bonaventure Project Vision includes three main objectives: Create a prestigious, functional and user-friendly gateway into the downtown core; Facilitate the re-weaving of the urban fabric through the removal of an elevated highway structure in the urban environment; Support private sector driven urban development through the implementation of key strategic initiatives in the downtown core.
North American cities need excellent bicycle infrastructure between regional destinations to allow residents to cycle long distances. Planners must make long distance bicycle travel feasible if they are serious about treating cycling as a form of mass transportation (Transport for London, 2014). Bicycle highways are high quality bicycle routes that connect major destinations and are designed for safe and comfortable long-distance travel. They facilitate comfortable and safe long distance travel. Preliminary research has shown that they are effective in increasing ridership and attracting users from other modes such as cars or transit. The purpose of this review is to offer guidance on how practitioners can plan, design, and implement bicycle highways as part of a bikeway network. The study draws upon literature and design guidance and seven case studies that are emerging in Europe and Asia. Through this review we propose a definition for bicycle highways, differentiate them from other bikeway facilities, present research on their effects, and characterize their planning, design, and implementation. We conclude this papers with seven policy takeaways for North American practitioners.
This paper summarizes the performance of a steel truss railway bridge near Saskatoon, SK, which remained in service during pile driving activities for pier rehabilitation and new pier construction. 289 H section piles were driven to embedment depths of 9 m for rehabilitation of existing concrete piers, and 12 m for new piers, for the western portion of the bridge, over an approximate one-month timeline. Piles for existing piers were driven within one metre of the existing pile caps, which were supported on timber piles. Monitoring instrumentation included surveying of prisms mounted to the bridge deck and piers and installation of tilt loggers, and a vibration monitoring system, to monitor the lateral deflection and accelerations, respectively, of the structure during pile driving. The collected data provides an understanding of the response of the bridge structure from pile driving into the hard foundation till, along with expansion and contraction effects due to extreme temperature variations. Survey and tilt logger data were found to correlate well together, and with changes in ambient temperature. Wave Equation Analysis of Pile Driving (WEAP) was conducted to estimate pile termination criteria and driving hammer performance. Pile Dynamic Analyzer (PDA) testing was conducted on 10% of the piles; 9 and 12 m long piles driven into Sutherland Till exhibited average vertical capacities in the range of 1,940 kN and 2,700 kN, respectively.
In the summer of 2015, Standard General Inc. – Calgary (SGIC), a subsidiary of Colas Canada Inc., introduced a new paving material called Betoflex® with the goal of resolving a recurring permanent deformation issue of two taxiways leading to Runway 17/35 at the Calgary Airport. The 2015 mixture was developed using the French Level 2 methodology to ensure that rutting resistance performance was achieved while maintaining good mixture workability to facilitate placement and compaction. In the spring/summer of 2016, Level 4 testing was performed on various Betoflex® mixtures that could potentially be used in the Calgary area. Level 4 testing was also performed on typical mixtures used in Calgary to benchmark Betoflex® with local mixtures. The Level 4 mix-design provides information for pavement design (stiffness modulus and fatigue resistance) using the French ALIZÉ-LCPC software. This paper provides an overall perspective of the engineering of asphalt mixtures to achieve “in-service” performance not only for durability (moisture resistance and rutting), but also for pavement design performance (stiffness modulus and fatigue resistance). It also discusses how the ALIZÉ-LCPC pavement design software uses Level 4 mix-design information to optimize pavement thicknesses and/or pavement performance reliability with respect to fatigue and large radius rutting.
Asphalt binder rejuvenator use in Hot Mix Asphalt (HMA) has been gaining momentum not only to delay aging of the asphalt binder, but also to permit higher levels of binder replacement from recycled materials. In this study, an HMA mixture was designed with approximately 35 percent binder replacement from Reclaimed Asphalt Pavement (RAP). Per specifications, a binder grade adjustment from PG 64-22 to PG 58-28 was required. The control mixture contained a neat PG 58-28 binder. Three experimental binders contained asphalt binder that were a blend of PG 64-22 plus rejuvenator materials to produce a PG 58—28 binder. HMA mixtures containing all four asphalt were tested for cracking and rutting resistance. The laboratory study indicated that the control and experimental mixes had no difference I rutting resistance. Under short-term aging, all three experimental mixtures with rejuvenators had improved cracking resistance as measured by the Illinois Flexibility Index Test (IFIT). Under long-term aging conditions, no significant difference was observed among the control and the three experimental mixtures according to the Disc-Shaped Compact Tension (DCT) test. However, IFIT testing of long-term aged specimens showed improved cracking resistance for two of the three experimental mixtures compared to the control.