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A Novel Back-Calculation Approach for Determining the Rheological Properties of RAP Binder

Wed, 11/08/2017 - 19:15
A Novel Back-Calculation Approach for Determining the Rheological Properties of RAP Binder
by Riccardi,C; Falchetto,AC; Leandri,P; Losa,M; Wistuba,MP.
2016.
Asphalt Paving Technology 2016: Journal of the Association of Asphalt Paving Technologists - Indianapolis, Indiana, March 13-16, 2016.
US6 AFN___ 2016P17 - MAIN


The determination of the rheological properties of the aged binder in reclaimed asphalt pavement (RAP) materials is a challenging problem. Conventionally, extraction and recovery are used to obtain the RAP binder for further experimental characterization; however, this procedure is not entirely reliable and accurate. Alternative and more precise approaches are based on asphalt mixture tests in combination with complex and sophisticated back-calculation methods which are costly and time consuming. In this paper a new and simple approach to estimate the rheological properties of RAP binder at intermediate temperature is proposed. This is based on Dynamic Shear Rheometer (DSR) tests performed on mortars, composed of a selected fine fraction of RAP and virgin binder, together with a new back-calculation solution. The properties of the bituminous blend of virgin and RAP binders are obtained through the manipulation of the Nielsen model equation to take into account the effects of frequency and temperature on mortar stiffness. The Voigt model is then used to estimate the complex modulus and the phase angle of the RAP binder from the complex modulus and the phase angle of the back-calculated binder blend.

Performance-Space Diagram for the Evaluation of High and Low Temperature Asphalt Mixture Performance

Wed, 11/08/2017 - 18:55
Performance-Space Diagram for the Evaluation of High and Low Temperature Asphalt Mixture Performance
by Buttlar,WG; Hill,BC; Wang,BC; Mogawer,W.
2016.
Asphalt Paving Technology 2016: Journal of the Association of Asphalt Paving Technologists - Indianapolis, Indiana, March 13-16, 2016.
US6 AFN___ 2016P16 - MAIN


This paper presents a simple, yet powerful method for simultaneously evaluating the high and low temperature performance of asphalt paving mixtures for the purpose of mixture design, evaluation, and forensic investigation. A performance-space diagram approach is described, with an emphasis on Hamburg-DC(T) plots presented in this paper. Specifically, a plot of Hamburg wheel tracking results, plotted in reverse order on the y-axis using an arithmetic scale, along with DC(T) fracture energy results, plotted on the x-axis, constitutes the Hamburg-DC(T) plot. Plotting candidate mixture designs, research results, etc., yields a surprising amount of insight towards mixture variables that affect overall performance. For instance, substitution of one straight-run binder grade for another results in a clear, predictable trade-off in the Hamburg-DC(T) performance space. Polymer modified grades, on the other hand, provide a more beneficial shift in the Hamburg-DC(T) space. The benefits of using this approach in the design of mixtures containing recycled asphalt mixture and recycled asphalt shingles are also presented. Effects of rejuvenators and the benefits of stone mastic asphalt designs are also demonstrated. Finally, a broad look at a large database of mixtures recently designed in Illinois is presented.

Design, Construction, Maintenance and Inspection Guide for Mechanically Stabilized Earth Walls

Tue, 10/31/2017 - 20:37
Design, Construction, Maintenance and Inspection Guide for Mechanically Stabilized Earth Walls
by Van Dyk,A; Bathurst,RJ; Maher,M; Boone,S.
2017.
CA6 ARH_63 2017D21 - MAIN


Mechanically stabilized earth (MSE) walls are a mature earth retention technology but concerns sometimes arise over who retains ultimate responsibility for wall design, quality assurance, asset management and repairs, and post-construction in-service monitoring, particularly if significant construction or performance problems occur. This guide provides owners, engineers, suppliers and contractors of MSE walls with practical guidance on the selection, design, construction, and inspection of these structures with a focus on public works projects. The guide was developed through reviews of published literature supplemented by a survey of industry stakeholders. It is not intended to reproduce the large volume of published design guidance and related information; rather the guide highlights aspects of the current state of practice in Canada and suggests modifications of current practice where deficiencies are apparent.

Guide de conception et gestion des actifs de chaussées

Tue, 10/31/2017 - 18:40
Guide de conception et gestion des actifs de chaussées
2013.
CA6 ARH_90 2013P11Z - MAIN


Ce Guide est une synthèse de pratiques canadiennes en matière de conception et de gestion des chaussées. Il offre un exposé théorique des enjeux, un résumé des meilleures pratiques et vise à être applicable partout au Canada, quelles que soient les conditions et l’administration routière. Il contient également des outils de gestion des actifs d'infrastructure de transport. Le Guide porte une attention particulière sur l'entretien courant et sur la préservation en tant que volets importants de la gestion des chaussées. Il attire l'attention sur les enjeux principaux touchant la durabilité, les changements climatiques. les innovations, ainsi que la conception et la gestion des routes à faible débit. Le Guide souligne explicitement les pratiques provinciales en plus des pratiques municipales.Il s'appuie sur l’expérience, mais tient également compte des besoins de l'avenir. Le document est un guide plutôt qu’un manuel détaillé de conception et chacun de ses quinze chapitres offre de nombreuses ressources additionnelles en tant que références futures. Le Guide est destiné à divers utilisateurs, praticiens et gestionnaires. Les utilisateurs universitaires en feront un précieux document de référence Les acteurs du secteur privé et public s'en serviront comme un outil de conception et de gestion pour la formation des nouveaux techniciens, ingénieurs et gestionnaires.

Effective Application of Complete Streets Design Principles for Enhancing Pedestrian Safety

Thu, 10/26/2017 - 21:38
Effective Application of Complete Streets Design Principles for Enhancing Pedestrian Safety
by Kirkham,P.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5126 - INTERNET


The Complete Street is rapidly being accepted and implemented in municipalities throughout the world to create a more inclusive and safe environment for all road users. The inability of many existing corridors to safely transport vulnerable road users to and from significant generators, while ensuring a road is also seen as a destination in and of itself, is an ongoing challenge municipalities face. Promoting the economic vibrancy of a corridor and the adjacent land uses through implementation of a safe, pedestrian-friendly, and aesthetically inviting corridor is quickly becoming a priority for many municipalities as antiquated design practices are superseded with new guidelines. This paper explores a real-world example of applied design principles employed to enhance road safety within an urban setting through exploration of a case study. The case study project area will be reviewed to identify why the specific corridor and surrounding area was identified for conversion to a Complete Street/Grand Boulevard. Complete Street design recommendations and best practices will be reviewed prior to exploring which key components were applied to the specific case study. An emphasis will be placed on the case study’s connectivity of a major transit hub to a significant shopping centre facility as well as the specific corridor enhancements applied to prioritize safe and efficient movement of vulnerable road users. A review of the custom roadway geometrics utilized to strike a balance between road safety, traffic operations, pedestrian accessibility, active modes, and transit will be explored. Applicable design standards and guidelines referenced during the design of the case study project will be reviewed and Complete Street design principles that were modified or compromised during design and construction will be discussed. The paper will examine the challenges of implementing Complete Streets design principles which often employ customized geometrics and do not necessarily correlate with historically approved best practices and design guidelines. From concept development to construction, the review and approval process will be explored to highlight some of the design compromises that were made to reach a balanced end product. The strategy for effective design and implementation of an urban corridor retrofit project will be presented with a breakdown of fundamental and applicable Complete Street best practices to create a safe and inviting experience for all road users.

Development, Construction and Operations of a new Traffic Calming Tool

Thu, 10/26/2017 - 21:38
Development, Construction and Operations of a new Traffic Calming Tool
by Churchill,AE; Domarad,J; Mishra,S.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5125 - INTERNET


Traffic calming measures continue to be effective ways of re-designing our roads to reduce speeds, increase yielding, and improve safety in our urban areas. The processes to implement traffic calming, however, can be long and arduous due to the many obstacles to permanent construction. In many cases the obstacles to implementation of traffic calming result in large delays during which time there are on-going safety concerns or collisions in many cases. These obstacles include funding, utilities, drainage and public support, to name a few. To overcome some of these obstacles the City of Calgary developed a pre-cast concrete shape, called Traffic Calming Curbs (TC Curbs) that allow modular creation of common traffic calming features that can be deployed quickly, at a low cost, and with a high degree of flexibility. The innovative process to design and construct the TC Curbs is described as well as process considerations for implementing their placement and lessons learned so far regarding their use. Case studies of TC Curb placement are examined including geometric design, placement, winter operations, and supporting traffic control. More importantly, evaluations of changes in motorist behaviours such as speed and yielding behaviour, and perceptions of various stakeholders are presented. Initial indications are that TC Curbs are a useful and effective tool to implement traffic calming as either an interim or potentially long term solution.

Development of Cross-Asset Comparative LOS Condition Index

Thu, 10/26/2017 - 21:38
Development of Cross-Asset Comparative LOS Condition Index
by St Michel,G; Reggin,A; Rafiei,K.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5124 - INTERNET


Comparing Level of Service (LOS) across infrastructure asset classes is difficult because of a lack of a common asset condition indicator. Some expert practitioners have suggested various types of asset value index as a common measure for comparing asset health but such an index, on its own, might mask the underlying level of service. In addition, quantifying risk and reliability is becoming ever more important when managing infrastructure assets. Asset Condition Indices are often composites of several measured or estimated asset attributes. Pavement Condition Indices, for example, are often derived by deducting values representing many different pavement distresses from a perfect score. However, when a composite index is used, the underlying nature of the severity of distress or its extent is not evident directly from the index. One must refer to the underlying individual distress data to determine why the index got its ultimate value. The magnitude of the deduct values are often somewhat subjective based on expert judgement relating to the relative severity of a given distress. In pavement, for instance, alligator cracking is seen to be more costly to repair than transverse cracking and is therefore given a larger deduct value resulting in a lower condition index. Although this may be reasonable for pavements, any mathematics behind the quantitative relationships between deduct values is not well documented in the literature. Quantifiable damage indices for pavements such as those used in the Highway Development and Management (HDM) framework have been in widespread use outside of North America and with the introduction of Mechanistic-Empirical Pavement Design Guide (MEPDG), are now gradually being adopted in North America providing a more consistently defined structure for quantifying pavement distress. This paper briefly discusses the evolution of the classes of pavement indices from the traditional composite class indices through to damage indices and into those developed or now being developed to manage some other infrastructure classes including Infrastructure Value Indices. The paper then puts forward a framework for incorporating risk and reliability with asset value indices in such a manner that both of these performance indicators could be compared across asset classes. Finally the paper describes a recently developed, damage based, LOS Index that can readily be applied to virtually any infrastructure asset class and that conveys not only the condition of the asset but allows Asset Managers to gauge the severity and density of distress through a single index number. The index can be readily implemented at any level of agency experience and requires no sophisticated data collection technology. The paper demonstrates the application of the technique through a municipal transportation infrastructure example.

Design and Implementation of the Manitoba Constrained-Width Tall Wall Barrier

Wed, 10/25/2017 - 21:31
Design and Implementation of the Manitoba Constrained-Width Tall Wall Barrier
by Larsen,HP; Rosenbaugh,SK; Pankratz,A; Emerson,D; Schmidt,JD; Faller,RK; Regier,EM.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5123 - INTERNET


Manitoba Infrastructure (MI) desired a new, tall concrete median barrier capable of satisfying the Test Level 5 (TL-5) safety requirements of the Manual for Assessing Safety Hardware (MASH). It needed to fit within the footprint of an existing F-shape median barrier located in a narrow median. It also was required to address headlight glare from opposing traffic. The barrier was designed with a height of 1,250 mm, a maximum width of 600 mm and to resist a load of 845 kN applied at the top of the barrier. The Manitoba Constrained-Width, Tall Wall was optimised to withstand the design load while minimising the amount of steel reinforcement. Variations of the barrier were developed, including a bridge rail and a roadside barrier. The bridge rail was considered to be the critical design due to its narrow width and anchorage to a relatively thin, cantilevered bridge deck. Thus, one full-scale vehicle crash test was conducted on the bridge rail system to verify the entire family of barriers. A vertical back barrier (45.72 m long) was constructed. It had a height of 1,250 mm and widths of 450 mm at its base and 250 millimetres at the top. The upstream half of the barrier (22.86 m) was constructed on a simulated bridge deck that was 280 mm thick. A gap in the bridge rail was constructed that was 168 mm wide and a gap in the bridge deck that was 19 mm wide; these were placed mid-span to simulate an expansion joint. A steel cover plate was placed over the barrier joint to prevent vehicle snag. During the test, the tractor trailer impacted just upstream from the joint and was safely redirected. The barrier sustained minor damage in the form of cracks and spalling. Anchorage options were developed for use with the TL-5 barrier system, including a foundation slab and an independent footing. Transition systems were also detailed for the connection of the TL-5 median barrier to various other new and existing barrier shapes. Finally, Manitoba Infrastructure developed a full series of barrier systems for median and roadside conditions that will provide designers many options to create construction drawings for their projects that are specific for their site(s).

Design and Construction of the Sir Ambrose Shea Vertical Lift Bridge Placentia, Newfoundland and Labrador

Wed, 10/25/2017 - 21:31
Design and Construction of the Sir Ambrose Shea Vertical Lift Bridge Placentia, Newfoundland and Labrador
by Ajrab,J; McCall,J; Power,D.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5122 - INTERNET


On September 23, 2016, the new Sir Ambrose Shea Vertical Lift Bridge located in the Province of Newfoundland and Labrador on the east coast of Canada opened to traffic. It was built as a replacement to an existing structure constructed in 1961 that had reached the end of its useful life. It is comprised of three spans, with a centre movable span (vertical lift span) flanked by two simple fixed composite plate girder spans. The towers for this lift bridge are comprised of a three-dimensional steel truss shaped representative of sails. Each tower component is connected by a three-dimensional exoskeleton truss housing the machinery operating the lift span. In addition to being aesthetically pleasing with architecture reflecting the local culture and tourism potential of the region, the new bridge is designed to be durable, efficient and reliable. The new bridge was constructed adjacent to the existing bridge in order to minimize disruption to navigation and road traffic. This paper discusses the bridge design and construction starting with the design aspects of the bridge including: movable bridge types considered; alternative lift span systems; foundation options; bridge architecture; mechanical components; durability; and constructability aspects of the design. The bridge foundations, approach spans, and towers were constructed using temporary trestles and cranes and the lift span was assembled on a barge and lifted into position. The construction duration spanned over a period of three years and had to accommodate the harsh environmental conditions including high winds, tide, and fast currents.

Design and Implementation of Channelized Right Turn Improvements in the City of Edmonton

Wed, 10/25/2017 - 21:31
Design and Implementation of Channelized Right Turn Improvements in the City of Edmonton
by McDonough,P; Ivany,M.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5121 - INTERNET


The City of Edmonton has committed to the long term goal of zero traffic fatalities and serious injuries. Moving towards that goal, the City of Edmonton has allocated funding for a multi-year traffic safety improvement program. One of the applications of the program is to apply engineering improvements to existing right turn geometries to increase visibility and reduce rear-end collisions. These enhancements have had positive, proven results for roadway users. This paper discusses the planning, geometric design, and construction of various right-turn improvements in the City of Edmonton over the past 5 years, and examines the results of each treatment. The City of Edmonton identified intersections with high right-turn collision frequencies and reviewed potential changes to reduce collisions. Three core design options have been adopted in the City’s design standards: simple radius, high-entry angle, and low-exit angle/free flow. A detailed review of the locations and intersections was conducted, including overall collision and operational data. Projected intersection traffic data was reviewed to ensure acceptable level of service for the right turn movement after the improvement is implemented. Project constraints include existing land/road use, utilities, existing intersection geometrics, traffic/truck volumes, right-of-way, traffic control devices (signals), sight-lines, and constructability. Balance with other roadway users (pedestrians) and driver expectation and familiarity was also considered. An evaluation matrix was used to weigh the constraints and then engineering judgement was applied to determine the most applicable improvement for each location. The intent of this paper is to present several case-studies and explain the lessons learned through all phases of design and implementation of various right-turn improvements in the City of Edmonton. Project successes and challenges will be discussed. The City of Edmonton’s future strategies for right-turn improvements, including data collection and monitoring, will be presented.

Deltaport Causeway Overpass: How to Construct a Complex Bridge Overpass on a Narrow Causeway in Challenging Soil Conditions

Wed, 10/25/2017 - 21:31
Deltaport Causeway Overpass: How to Construct a Complex Bridge Overpass on a Narrow Causeway in Challenging Soil Conditions
by Culpan,S; Jiang,J.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5120 - INTERNET


The Deltaport Causeway Overpass in Vancouver B.C. was the centerpiece of a $45 million upgrade of the transportation infrastructure at Canada’s busiest container port terminal. The project included the design and construction of a curved overpass located on a narrow causeway in an area of highly sensitive soils. The aim of the project was to improve vehicle access to the terminal by separating road and railway traffic at a critical bottleneck junction, and to contribute an additional 200,000 container units of annual capacity at the port. This paper describes the technical challenges and the engineering solutions that were used to design the structures to accommodate the tight geometric constraints of the site while ensuring minimal impact to terminal operations. The key technical challenges included: 1. The design of very slender bridge columns due to the close proximity of the rail tracks. The innovative design used small-diameter reinforced concrete columns with an externally-bonded fiber-reinforced polymer (FRP) wrap. The FRP wrap was designed to confine the concrete core, and ensure the columns had sufficient ductility to meet the structural design capacity; 2. The design of expanded-base concrete ‘Franki’ piles founded within a zone of stone-column ground improvement. Franki piles were the preferred piling system because the depth to bedrock precluded the installation of deep-pile foundations. The Franki piles were constructed by driving a zero-slump concrete mix out the bottom of a steel casing to form the load-bearing compression and tension bulbs; 3. The design of a state-of-the-art lightweight-fill solution for the bridge-approach embankments using expanded polystyrene (EPS) blocks, aka “geofoam”. The lightweight properties of EPS allowed the approaches to be constructed at a relatively shallow depth, and limited the weight applied to the load-sensitive foundation soils.

Creation of the Bonshaw Hills Provincial Park and Protection of Provincially Owned Land

Wed, 10/25/2017 - 21:31
Creation of the Bonshaw Hills Provincial Park and Protection of Provincially Owned Land
by Thompson,B.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5119 - INTERNET


The Bonshaw Hills Public Lands Committee is a multi-stakeholder committee, comprised of government and non-government individuals, representing organizations from the Transportation, Tourism, Conservation, Education, Trail Building and Cycling communities. This Committee, through its work which began in January, 2013 has successfully protected more than 600 acres of public land under the Natural Areas Protection Act, constructed more than 20 kms of multi use trail on public land, and constructed a natural playground for the enjoyment and use of all.

CPR Yards Functional Design Crossing Study

Tue, 10/24/2017 - 22:36
CPR Yards Functional Design Crossing Study
by Boissonneault,M; Amy,K; Suderman,S.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5118 - INTERNET


Stantec was retained by the City of Winnipeg to complete a Functional Design Crossing Study over the CPR Yards located in North West Winnipeg. The Yards were constructed in the late 1800s at the outer limits of the City. Over one hundred years later, the Yards seem to divide the North End community of Winnipeg. There are three existing crossings over the 5km long and 1km wide Yards, located along McPhillips, Arlington and Salter Streets. The existing 37 span Arlington Street Bridge, constructed in 1912, is at the end of its functional life and is proposed to be decommissioned in approximately 5 years. The intent of the study was to develop a cost effective functional transportation plan for the removal of the existing Arlington Street Bridge and a preliminary decommissioning plan for the existing Bridge. Considering vehicular and active modes of transportation the transportation plan determined if and where a new crossing would be optimally located. The study addressed railway yard operations and coordination for the proposed decommissioning and new crossing construction. The transportation plan considered current and estimated traffic volumes in 2031. CPR was involved in the development of the decommissioning plan, which consisted of the removal of the spans in 6 - 10 hour track blocks via SPMT methods, as well as the new crossing concepts. The paper will discuss the plan in detail and how we addressed transportation and CPR requirements.

Conservation Dogs to Detect Blanding’s Turtle Nests prior to Road Rehabilitation Activities

Tue, 10/24/2017 - 22:36
Conservation Dogs to Detect Blanding’s Turtle Nests prior to Road Rehabilitation Activities
by Priddle,M.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5117 - INTERNET


Blanding’s Turtles nest in the granular shoulders of roadways, burying eggs beneath the ground surface. Visual detection of nests is not possible. Highway rehabilitation can damage or destroy eggs from May 21 to October 31. Detection dogs were trained in Ontario to locate Blanding’s Turtles nests, a federally and provincially listed Species at Risk, along roadways. This work contributes directly to environmental protection during road infrastructure renewal and conservation of species at risk turtles.

Concrete Sidewalk Design Analysis and Optimization for Improved Life Cycle and Sustainability

Tue, 10/24/2017 - 22:36
Concrete Sidewalk Design Analysis and Optimization for Improved Life Cycle and Sustainability
by Czarnecki,B; Poon,B.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5116 - INTERNET


The City of Calgary (The City) has a multimillion-dollar sidewalk replacement backlog. The condition-based preventive maintenance and the corrective maintenance are faced with challenges with limited manpower to conduct condition assessments and funding for sidewalk maintenance. A survey of the current sidewalk designs specified across major municipalities in Canada confirmed that the sidewalk structure in Calgary, including concrete thickness and the use of granular base materials, is one of the thinnest. The most common sidewalk damage/failure patterns in cold climates are well recognized, but the impact of the sidewalk design on the service life and the maintenance needs relies predominantly on limited inspections and reporting process for the asset. The structural assessment of different sidewalk designs was conducted using the finite element analysis (FEA). The model inputs were selected based on local climate and variations in concrete thickness, base material thickness, and soil conditions. A total of 36 models were analyzed for structural adequacy and the findings of the FEA formed the basis for the Best Construction Practices recommendations for concrete sidewalks in Calgary. The rationale behind the recommended changes to the sidewalk structure is discussed in conjunction with the need for a more stringent quality assurance and verification process. The life cycle cost analysis of selected designs is provided. The importance of data management to assess the effectiveness of the sidewalk repairs and to determine the rate of sidewalk deterioration is recognized.

Comparison between AASHTO and CHBDC Design Methods for MSE Retaining Wall and its Implications on Transportation Agencies

Mon, 10/23/2017 - 20:36
Comparison between AASHTO and CHBDC Design Methods for MSE Retaining Wall and its Implications on Transportation Agencies
by Essery,D; Taylor,TP; El-Sharnouby,M.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5115 - INTERNET


Mechanically Stabilized Earth (MSE) structures have been used in their current form since the early 1970s. MSE structures have become the solution of choice over traditional retaining wall systems due to their reduced material costs, ease of installation, and improved performance. This results in a retaining wall system that has a reduced carbon footprint when compared to other retaining wall systems such as Cast-in-Place wall systems. Design of MSE structures has progressed from using the Allowable Stress Design(ASD) method to the Load and Resistance Factored Design (LRFD) method. The American Association of State Highway and Transportation Official (AASHTO) implemented the LRFD method to design MSE structures in 2002 and has established load and resistance factors through calibration to the ASD method, experience and collaboration with the MSE industry. This paper will compare the design of an inextensible reinforced MSE wall system using the latest edition of Canadian Highway Bridge Code (CHBDC, CAN/CSA-S6-14) to the AASHTO (2014) LRFD Bridge Design Specification. This paper will demonstrate how the CHBDC new changes increase the cost of a typical MSE structure. Indirectly, it will demonstrate the present sustainability issues being faced with the current CHBDC design method including, an increase in the steel reinforcement required to be manufacture and the additional select MSE fill that will be required to be processed and shipped to site, resulting in an increase in the carbon footprint for the structure.

Clean Roads to Clean Air Program

Mon, 10/23/2017 - 20:36
Clean Roads to Clean Air Program
City of Toronto.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5114 - INTERNET


Toronto’s Transportation Services Division (TSD) developed and implemented the Clean Roads to Clean Air Program (CRCA) in 2005. The program helped to develop procedures and standards to evaluate the operational and environmental (PM10 and PM2.5 efficiency) performance levels of various street sweeper technologies, and created a framework for continual assessment and improvement of sweeping practices. A significant outcome of the program was the development of two sweeper testing protocols: “Operational On-Street”; “PM10 and PM2.5 Street Sweeper Efficiency”; and their respective performance criteria. These two testing protocols were adopted by the Environment Canada and Climate Change (ECCC) Environmental Technology Verification Program (ETV (http://etvcanada.ca/), which provides third party verification services.

Centre City Cycle Track Network Pilot Project In-Service Safety Review

Mon, 10/23/2017 - 20:36
Centre City Cycle Track Network Pilot Project In-Service Safety Review
by Patterson,B.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5113 - INTERNET


Concern for safety is one of the most important deterrents to increasing cycling. By conducting this project, the City is demonstrating its commitment to a sustainable transportation system and the high degree of importance placed on vulnerable road users in creating a safe, multi-modal transportation system. By focusing on targeted improvements to improve cycling safety, The City can help to make cycling more convenient, attractive, safe, and normal way to travel through the City. This project will help the City to achieve its targets related to increasing the mode share of sustainable transportation and reducing traffic related injuries and fatalities.

Case Studies and Innovative Uses of GPR for Pavement Engineering Applications

Mon, 10/23/2017 - 20:36
Case Studies and Innovative Uses of GPR for Pavement Engineering Applications
by Korczak,R; Abd El Halim,A.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5112 - INTERNET


Over the past few decades, advances in technology has allowed electronics and computers in general to become more portable and to be able to store more data than ever before. Ground Penetrating Radar (GPR) is a non-destructive technology that is typically associated with archaeological studies, but has recently become more prevalent in civil engineering field with applications ranging from subsurface utility detection to structural concrete assessments. The principle of GPR technology is based on the reflection/transmission of microwave electromagnetic energy and recording its response to different materials, which are governed by two physical properties of the material; electrical conductivity and dielectric constant. For reflections to occur at different material interfaces, there must be a contrast in dielectric value (reflection produced at a boundary where the dielectric value changes). During subsurface material/void detection, depending on the size of the target, there will generally be a distinct reflection due to the contrast in dielectric between the subsurface materials and the target structure. Generally, GPR data is collected using two types of systems: air-coupled and ground-coupled systems. Air-coupled systems are typically vehicle mounted and use an antenna frequency between 1.0 to 2.0 GHz which is capable of a depth of penetration ranging from 0.75 m to 0.9 m below the ground surface. There are a large variety of ground-coupled systems, but typically are mounted using a cart with single, or multiple wheels depending on the size of the antenna and must have constant contact with the surface being scanned. Antenna frequencies range from 16 to 2,600 MHz with depth of penetration ranging from 0.3 m to 50 m. This paper presents several case studies using both air-coupled and ground-coupled GPR systems in pavement engineering applications ranging from void detection, Species at Risk (SAR) investigations, subsurface utility/structure detection and concrete reinforcement detection. The results of the case studies show that GPR is a non-destructive data collection method that can be used in several different ways to collect a large amount of data over a large area relatively quickly compared to typical investigation methods (coring or drilling). It is important to understand the limitations of the equipment (signal penetration, size of target, etc.), as well as the appropriate system to use in a specific situation (air-coupled vs. ground-coupled). Ground truth data was also critical in the data analysis and interpretation of the GPR scans. Additionally, using the utility survey cart-mounted antenna in a cross-polarized orientation aided in capturing data in a steel congested structural element and allowed the GPR engineers to help identify voids.

Safety Evaluation of Cable Median Barriers in Combination with Rumble Strips on the Inside Shoulder of Divided Roads

Wed, 10/18/2017 - 20:35
Safety Evaluation of Cable Median Barriers in Combination with Rumble Strips on the Inside Shoulder of Divided Roads
by Srinivasan,R; Lan,B; Carter,D; Persaud,B; Eccles,K.
2017.
US1 DTH680 2017S12 - MAIN


The Development of Crash Modification Factors program conducted the safety evaluation of cable median barriers in combination with rumble strips on the inside shoulder of divided roads for the Evaluation of Low cost Safety Improvements pooled Fund Study. This study evaluated safety effectiveness of cable median barriers in combination with rumble strips on the inside shoulders of divided roads. This strategy is intended to reduce the frequency of cross-median crashes, which tend to be very severe. Geometric, traffic, and crash data were obtained for divided roads in Illinois, Kentucky, and Missouri. To account for potential selection bias and regression-to-the-mean, an empirical Bayes before-after analysis was conducted using reference groups of untreated roads with characteristics similar to those of the treated sites. the analysis also controlled for changes in traffic volumes over time and time trends in crash counts unrelated to the treatment. In Illinois and Kentucky, cable median barriers were introduced many years after the inside shoulder rumble strips were installed; therefore, the evaluation determined the safety effect of implementing cable barriers along sections that already had rumble strips. Conversely, in Missouri, the inside shoulder rumble strips and cable barrier were implemented around the same time' Hence, the evaluation in Missouri determined the combined safety effect of inside shoulder rumble strips and cable barriers. The combined Illinois and Kentucky results indicate about a 27-percent increase in total crashes; a 24-percent decrease in fatal, incapacitating, non-incapacitating, and possible injury crashes; a 22-percent decrease in fatal, incapacitating, and non-incapacitating injury crashes; and a 48-percent decrease in head-on plus opposite-direction sideswipe crashes (used as a proxy for cross-median crashes). The results from Missouri for total and injury and fatal crashes were very similar to the combined Illinois and Kentucky results. However, the reduction in cross-median crashes in Missouri was much more dramatic, showing a 96-percent reduction (based on cross-median indicator only) and an 88-percent reduction (based on cross-median-indicator plus head-on). The economic analysis for benefit-cost ratios shows that this strategy is cost-beneficial.

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