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Size Effect in Asphalt Mixture at Low Temperature: Type I and Type II

Tue, 08/08/2017 - 18:05
Size Effect in Asphalt Mixture at Low Temperature: Type I and Type II
by Falchetto,AC; Wistuba,MP; Marasteanu,MO.
2016.
Asphalt Paving Technology 2016: Journal of the Association of Asphalt Paving Technologists - Indianapolis, Indiana, March 13-16, 2016.
US6 AFN___ 2016P11 - MAIN


Low temperature cracking is a serious distress for asphalt pavement built in cold regions, such as the northern U.S. and northern Europe. Therefore, accurate assessment of the strength and fracture properties of asphalt mixtures is fundamental for ensuring the long term integrity of the entire pavement structure. It has been shown that asphalt mixtures behave in a quasibrittle manner at low temperatures and, consequently, their nominal strength strongly depends on the structure size. Most of the research performed in the past has experimentally addressed this phenomenon either on unnotched or deep-notched specimens corresponding to Type I and Type II size effects, respectively. However, the evolution of the pavement conditions during the service life can lead to the formation and propagation of cracks which strongly affect the response of the material and, eventually, determine a complex size effect. In this paper a comprehensive experimental study is performed to evaluate the effect of different notch depths on the scaling law for quasibrittle fracture. Three-point bending tests are performed on plain and notched asphalt mixture beams of different sizes at low temperature. The results on unnotched specimens are analyzed through the Type I energetic-statistical size effect law (SEL) in combination with the weakest link model, while, in the case of deep notched specimens, the Type II SEL is used. A significant variation in the evolution of the SEL is observed with a dramatic decrease in strength over size and notch length. In addition, an empirical relation between the initial fracture energy, Gf, and the total fracture energy, GF, is found, and the characteristic length, cf, associated to the length of fracture process zone, is determined.

Asphalt Mixtures Containing RAS and/or RAP: Relationships amongst Binder Composition Analysis and Mixture Intermediate Temperature Cracking Performance

Tue, 08/08/2017 - 17:46
Asphalt Mixtures Containing RAS and/or RAP: Relationships amongst Binder Composition Analysis and Mixture Intermediate Temperature Cracking Performance
by Cooper,SB Jr; Negulescu,I; Balamurugan,SS; Mohammad,L; Daly,WH; Baumgardner,GL.
2016.
Asphalt Paving Technology 2016: Journal of the Association of Asphalt Paving Technologists - Indianapolis, Indiana, March 13-16, 2016.
US6 AFN___ 2016P10 - MAIN


The use of recycled asphalt shingles (RAS) as a partial replacement for petroleum-based virgin asphalt binder has received considerable attention in recent years. The objective of this study is to correlate the molecular structure and corresponding compositional analysis of asphalt binders of conventional asphalt mixtures as well as of mixtures containing recycled asphalt shingles (RAS) and/or reclaimed asphalt pavement (RAP) with their cracking potential at intermediate temperature. Laboratory testing evaluated the molecular composition of asphalt binders obtained from asphalt mixtures evaluated in this study using thin layer chromatograph/FID (Iatroscan) and gel permeation chromatography (GPC). Fracture resistance of laboratory-produced mixtures was assessed using the semicircular bend (SCB) test at intermediate temperature. Molecular fractionation through GPC of RAS samples confirmed the presence of associated asphaltenes in greater concentrations than recycled asphalt pavement (RAP) samples. High concentrations of high molecular weight asphaltenes decrease the fracture resistance of the asphalt mixtures. The use of rejuvenating agents, Cyclogen-L, Hydrogreen, asphalt flux and re-refined engine oil bottoms (REOB), did not reduce the concentration of the highly associated asphaltenes; further they failed to improve the cracking resistance of the asphalt mixtures evaluated in this study.

Effect of Rejuvenator on Performance Characteristics of High RAP Mixture

Tue, 08/08/2017 - 17:30
Effect of Rejuvenator on Performance Characteristics of High RAP Mixture
by Tran,N; Taylor,A; Turner,P; Holmes,C; Porot,L.
2016.
Asphalt Paving Technology 2016: Journal of the Association of Asphalt Paving Technologists - Indianapolis, Indiana, March 13-16, 2016.
US6 AFN___ 2016P09 - MAIN


As more reclaimed asphalt pavement (RAP) is utilized in asphalt mixtures, there are increasing concerns about the potential negative effect of the aged RAP binder on the field performance, especially cracking resistance, of high RAP mixtures. To address the concerns, there has been increasing interest in utilizing rejuvenators to improve the cracking performance of high RAP mixtures. The objective of this study was to determine the benefits of using a new rejuvenator made from renewable sources in asphalt mixtures with high RAP contents. The study was conducted by determining and comparing the laboratory performance properties of three mixtures and the binders extracted from the mixes. The three mixtures evaluated in this study included two 50% RAP mixtures (RAP binder ratio = 0.55) with and without the rejuvenator and a comparable virgin mix. Results of this study suggested that the new rejuvenator was effective in improving both the intermediate and low temperature cracking performance characteristics of the 50% RAP mix close to those of the virgin mix at the short-term laboratory aging condition without affecting its rutting and stripping resistance. It is recommended that a field study of this rejuvenator be conducted to further evaluate its effect on the long-term field performance of high RAP mixes.

Using Binder and Mixture Space Diagrams to Evaluate the Effect of REOB on Binders and Mixtures after Aging

Tue, 08/08/2017 - 17:16
Using Binder and Mixture Space Diagrams to Evaluate the Effect of REOB on Binders and Mixtures after Aging
by Mogawer,WS; Austerman,A; Al-Qadi,IL; Buttlar,W; Ozer,H; Hill,B.
2016.
Asphalt Paving Technology 2016: Journal of the Association of Asphalt Paving Technologists - Indianapolis, Indiana, March 13-16, 2016.
US6 AFN___ 2016P08 - MAIN


This study was conducted to address some of the New England state transportation agencies’ concerns associated with the use of Re-refined Engine Oil Bottoms (REOB) in asphalt binders and mixtures. The effects of REOB on the physical and rheological properties of an asphalt binder were investigated. This evaluation was completed after AASHTOspecified short-term and long-term aging and after extended long-term aging. Also, the effect of REOB modified binders on the performance of asphalt mixtures after short- and long-term aging was evaluated in terms of moisture damage, rutting, and cracking. Two straight run binders (PG 58-28 and PG 64-22), a typical PG 64-28, two sources of REOB, an aromatic oil, and PolyPhosphoric Acid (PPA) were utilized. The PG 64-22 was modified with each source of REOB separately to attain a PG 58-28. These modified PG 58-28 binders were compared to the straight run PG 58-28. The modified and the straight run PG 58-28 binders were further modified with PPA to attain a PG 64-28 which is commonly specified in the Northeast. This modified PG 64-28 was compared to a typical PG 64-28 that has been used in the past without REOB. This same binder modification to attain a PG 58-28 and PG 64-28 was repeated with the aromatic oil for comparison purposes. Rheological results plotted on the Black Space and wo—R-value Space diagrams showed that the addition of REOB to attain the PG 58-28 caused the binders to age more relative to the straight run binder. The results also indicated that the use of higher dosages of REOB can cause increased binder aging. Mixture moisture damage tests showed that REOB could result in mixture premature failure. The rutting tests indicated that generally the REOB did not cause the mixtures to fail. Cracking tests conducted at intermediate temperature on REOB-modified mixtures generally indicated a reduction in fracture energy, as compared to the straight run or typical binder counterpart. A flexibility index (FI) calculated from the same cracking test showed that the aromatic oil modified mixtures generally had a higher value than the REOB modified mixtures suggesting less susceptibility to cracking. Interaction plots developed using the FI and Hamburg test results revealed significant differences among mixes with various binder formulations and the effects of long-term aging on the interaction plots were evident. Low temperature cracking evaluations detected minor effects on low-temperature fracture properties associated with various combinations of REOB tested. Performance space diagrams indicated that the REOB modified mixtures remained within the passing zone in a Hamburg Wheel Tracking-Disc Shaped Compact Tension DC(T) tests diagram for low to medium traffic level. Overall, the particular mixture tests used in this study did not provide evidence that using REOB decreases performance. The performance data collected by using the two REOB sources varied by the particular test, and sometimes by the type of REOB or by the PG of the binder. The use of aromatic oil did not show this variability and the results generally indicated good performance. The variability of the data when REOB was used underscores the importance of thoroughly testing REOB modified binder and mixture for performance. Finally, other important issues like dosage and consistency of REOB are still currently being investigated.

24th World Road Congress Proceedings: Roads for a Better Life: Mobility, Sustainability and Development

Wed, 07/26/2017 - 20:36
24th World Road Congress Proceedings: Roads for a Better Life: Mobility, Sustainability and Development
2011.
ZZ IPR___ 2011C55 CDROM - CD


Papers were presented on a wide variety of subject matter including: Environmental Evaluation of Road Projects; Innovative Road Management Arrangements; Funding of Road Infrastructure; Shadow and Direct User Toll (PPP); Economic Aspects of Mobility Pricing; New Approaches to Appraisal of Social Impacts of Road Projects; Sustainable Maintenance of Rural Roads; Project Governance and Institutional Integrity; Capturing and Understanding Customer Needs; Human Resources for the Future; Management of Roads; Keeping Cities Moving; Freight Transport; Winter Service in Latin America; Linear Settlements: the World-Wide Disaster for Road Safety; Methods for Road Safety Impact Assessments; Road Safety System Approach; The System Approach of Human Factors in Road Design and Operations; Managing Operational Risk in the Road Sector; Sustainable Approaches for Road Tunnels; Adaptation of Road Pavements to Climate Change; Innovation in Road Pavements; Road Bridges; Innovations in the Treatment and Use of Marginal Local Materials; Innovations in Construction and Maintenance of Unpaved Roads in Developing Countries.

Proceedings of XXIInd PIARC World Road Congress, 19-25 October 2003, Durban, South Africa

Wed, 07/26/2017 - 20:36
Proceedings of XXIInd PIARC World Road Congress, 19-25 October 2003, Durban, South Africa
2003.
ZZ IPR___ 2003C55 CDROM - CD

Geometric Design Guide for Canadian Roads: Chapter 10 - Interchanges

Tue, 07/25/2017 - 14:14
Geometric Design Guide for Canadian Roads: Chapter 10 - Interchanges
by Chiu,M; Clayton,C; Millen,G; et al.
2017.
CA6 ARH_85 2017G22 Ch.10 - REF


The Geometric Design Guide for Canadian Roads contains the current design and human factors research and practices for roadway geometric design. It replaces the 1999 edition of the Guide and subsequent revisions. The Guide provides guidance to planners and designers in developing design solutions that meet the needs of a range of users while addressing the context of local conditions and environments. Design guidelines for freeways, arterials, collectors, and local roads, in both urban and rural locations are included as well as guidance for integrated bicycle and pedestrian design. The Guide is organized into ten chapters to cover the entire design process from design philosophy and roadway classification to design parameters and specific guidelines for the safe accommodation of vehicles, cyclists and pedestrians on linear road elements and at intersections. The chapters are: Design Philosophy; Design Controls, Classification and Consistency; Alignment and Lane Configuration; Cross Section Elements; Bicycle Integrated Design; Pedestrian Integrated Design; Roadside Design; Access; Intersections; and Interchanges. Chapter 10 – Interchanges provides a summary of relevant human factor aspects and warrants for interchanges. Guidance is provided on interchange location, spacing, coordination and a range of interchange types. Detailed guidance is provided for interchange exit and entrance ramp design.

Geometric Design Guide for Canadian Roads: Chapter 9 - Intersections

Tue, 07/25/2017 - 14:14
Geometric Design Guide for Canadian Roads: Chapter 9 - Intersections
by Chiu,M; Clayton,C; Millen,G; et al.
2017.
CA6 ARH_85 2017G22 Ch.09 - REF


The Geometric Design Guide for Canadian Roads contains the current design and human factors research and practices for roadway geometric design. It replaces the 1999 edition of the Guide and subsequent revisions. The Guide provides guidance to planners and designers in developing design solutions that meet the needs of a range of users while addressing the context of local conditions and environments. Design guidelines for freeways, arterials, collectors, and local roads, in both urban and rural locations are included as well as guidance for integrated bicycle and pedestrian design. The Guide is organized into ten chapters to cover the entire design process from design philosophy and roadway classification to design parameters and specific guidelines for the safe accommodation of vehicles, cyclists and pedestrians on linear road elements and at intersections. The chapters are: Design Philosophy; Design Controls, Classification and Consistency; Alignment and Lane Configuration; Cross Section Elements; Bicycle Integrated Design; Pedestrian Integrated Design; Roadside Design; Access; Intersections; and Interchanges. Chapter 9 – Intersections provides design guidance on intersections including roundabouts, innovative intersections and at-grade railroad crossings. A summary of relevant human factor aspects and an intersection planning and design process are provided. The design process identifies the relevant inputs and possible constraints. Guidelines on intersection spacing, layout and alignment and sight distance needs are summarized. Design details and guidance for simple intersections, channelization, tapers, auxiliary and turning lanes are outlined.

Geometric Design Guide for Canadian Roads: Chapter 8 - Access

Tue, 07/25/2017 - 14:14
Geometric Design Guide for Canadian Roads: Chapter 8 - Access
by Chiu,M; Clayton,C; Millen,G; et al.
2017.
CA6 ARH_85 2017G22 Ch.08 - REF


The Geometric Design Guide for Canadian Roads contains the current design and human factors research and practices for roadway geometric design. It replaces the 1999 edition of the Guide and subsequent revisions. The Guide provides guidance to planners and designers in developing design solutions that meet the needs of a range of users while addressing the context of local conditions and environments. Design guidelines for freeways, arterials, collectors, and local roads, in both urban and rural locations are included as well as guidance for integrated bicycle and pedestrian design. The Guide is organized into ten chapters to cover the entire design process from design philosophy and roadway classification to design parameters and specific guidelines for the safe accommodation of vehicles, cyclists and pedestrians on linear road elements and at intersections. The chapters are: Design Philosophy; Design Controls, Classification and Consistency; Alignment and Lane Configuration; Cross Section Elements; Bicycle Integrated Design; Pedestrian Integrated Design; Roadside Design; Access; Intersections; and Interchanges. Chapter 8 – Access provides guidelines for access management for the full range of road classifications. Guidance is provided for each classification of roadway in balancing traffic mobility needs and access to adjacent lands. Design guidance is provided for access location and geometrics and the use auxiliary lanes, two-way left-turn lanes and service roads to accommodate access in a safe manner.

Geometric Design Guide for Canadian Roads: Chapter 7 - Roadside Design

Tue, 07/25/2017 - 14:14
Geometric Design Guide for Canadian Roads: Chapter 7 - Roadside Design
by Chiu,M; Clayton,C; Millen,G; et al.
2017.
CA6 ARH_85 2017G22 Ch.07 - REF


The Geometric Design Guide for Canadian Roads contains the current design and human factors research and practices for roadway geometric design. It replaces the 1999 edition of the Guide and subsequent revisions. The Guide provides guidance to planners and designers in developing design solutions that meet the needs of a range of users while addressing the context of local conditions and environments. Design guidelines for freeways, arterials, collectors, and local roads, in both urban and rural locations are included as well as guidance for integrated bicycle and pedestrian design. The Guide is organized into ten chapters to cover the entire design process from design philosophy and roadway classification to design parameters and specific guidelines for the safe accommodation of vehicles, cyclists and pedestrians on linear road elements and at intersections. The chapters are: Design Philosophy; Design Controls, Classification and Consistency; Alignment and Lane Configuration; Cross Section Elements; Bicycle Integrated Design; Pedestrian Integrated Design; Roadside Design; Access; Intersections; and Interchanges. Chapter 7 – Roadside Design introduces road safety concepts and the use of quantitative analysis to evaluate roadside safety design options. The fundamental concept of the clear zone is outlined and how the concept can be applied through provision of appropriate cross section and drainage elements to allow for driver recovery. Mitigation and protection techniques to reduce the severity of fixed-object collisions with roadside furniture including signs, luminaires and traffic barriers are outlined. A discussion of roadside design in urban environments and for low volume roads is also included.

Geometric Design Guide for Canadian Roads: Chapter 6 - Pedestrian Integrated Design

Tue, 07/25/2017 - 14:14
Geometric Design Guide for Canadian Roads: Chapter 6 - Pedestrian Integrated Design
by Chiu,M; Clayton,C; Millen,G; et al.
2017.
CA6 ARH_85 2017G22 Ch.06 - REF


The Geometric Design Guide for Canadian Roads contains the current design and human factors research and practices for roadway geometric design. It replaces the 1999 edition of the Guide and subsequent revisions. The Guide provides guidance to planners and designers in developing design solutions that meet the needs of a range of users while addressing the context of local conditions and environments. Design guidelines for freeways, arterials, collectors, and local roads, in both urban and rural locations are included as well as guidance for integrated bicycle and pedestrian design. The Guide is organized into ten chapters to cover the entire design process from design philosophy and roadway classification to design parameters and specific guidelines for the safe accommodation of vehicles, cyclists and pedestrians on linear road elements and at intersections. The chapters are: Design Philosophy; Design Controls, Classification and Consistency; Alignment and Lane Configuration; Cross Section Elements; Bicycle Integrated Design; Pedestrian Integrated Design; Roadside Design; Access; Intersections; and Interchanges. Chapter 6 – Pedestrian Integrated Design provides guidance and examples on how to integrate holistically the design of pedestrian facilities into roadway design to achieve a balanced solution for all modes and road users. Guidance is provided on pedestrian and wheelchair design needs, use of a framework approach to design, which subdivides the roadside into frontage, pedestrian through and furnishing zones and specific design elements. Integration with other design elements including adjacent roadway lane widths, roundabouts and bridges and other travel modes is addressed.

Geometric Design Guide for Canadian Roads: Chapter 5 - Bicycle Integrated Design

Tue, 07/25/2017 - 14:14
Geometric Design Guide for Canadian Roads: Chapter 5 - Bicycle Integrated Design
by Chiu,M; Clayton,C; Millen,G; et al.
2017.
CA6 ARH_85 2017G22 Ch.05 - REF


The Geometric Design Guide for Canadian Roads contains the current design and human factors research and practices for roadway geometric design. It replaces the 1999 edition of the Guide and subsequent revisions. The Guide provides guidance to planners and designers in developing design solutions that meet the needs of a range of users while addressing the context of local conditions and environments. Design guidelines for freeways, arterials, collectors, and local roads, in both urban and rural locations are included as well as guidance for integrated bicycle and pedestrian design. The Guide is organized into ten chapters to cover the entire design process from design philosophy and roadway classification to design parameters and specific guidelines for the safe accommodation of vehicles, cyclists and pedestrians on linear road elements and at intersections. The chapters are: Design Philosophy; Design Controls, Classification and Consistency; Alignment and Lane Configuration; Cross Section Elements; Bicycle Integrated Design; Pedestrian Integrated Design; Roadside Design; Access; Intersections; and Interchanges. Chapter 5 – Bicycle Integrated Design provides guidance and examples on how to integrate holistically the design of bicycle facilities into the roadway design to achieve a balanced solution for all modes and road users. Guidance is provided on bicycle and inline skater design needs, types of bicycle facilities and a framework for the selection of an appropriate type of facility, and specific design elements.

Geometric Design Guide for Canadian Roads: Chapter 4 - Cross Section Elements

Tue, 07/25/2017 - 14:14
Geometric Design Guide for Canadian Roads: Chapter 4 - Cross Section Elements
by Chiu,M; Clayton,C; Millen,G; et al.
2017.
CA6 ARH_85 2017G22 Ch.04 - REF


The Geometric Design Guide for Canadian Roads contains the current design and human factors research and practices for roadway geometric design. It replaces the 1999 edition of the Guide and subsequent revisions. The Guide provides guidance to planners and designers in developing design solutions that meet the needs of a range of users while addressing the context of local conditions and environments. Design guidelines for freeways, arterials, collectors, and local roads, in both urban and rural locations are included as well as guidance for integrated bicycle and pedestrian design. The Guide is organized into ten chapters to cover the entire design process from design philosophy and roadway classification to design parameters and specific guidelines for the safe accommodation of vehicles, cyclists and pedestrians on linear road elements and at intersections. The chapters are: Design Philosophy; Design Controls, Classification and Consistency; Alignment and Lane Configuration; Cross Section Elements; Bicycle Integrated Design; Pedestrian Integrated Design; Roadside Design; Access; Intersections; and Interchanges. Chapter 4 – Cross Section Elements provides guidance on design procedures and domains related to cross sections and related elements including special purpose lanes, shoulders, medians, outer separations and boulevards, curb and gutter and drainage. Considerations for bridges and utility placement, snow storage and future widening are discussed and a series of typical cross sections are provided.

Geometric Design Guide for Canadian Roads: Chapter 3 - Alignment and Lane Configuration

Tue, 07/25/2017 - 14:14
Geometric Design Guide for Canadian Roads: Chapter 3 - Alignment and Lane Configuration
by Chiu,M; Clayton,C; Millen,G; et al.
2017.
CA6 ARH_85 2017G22 Ch.03 - REF


The Geometric Design Guide for Canadian Roads contains the current design and human factors research and practices for roadway geometric design. It replaces the 1999 edition of the Guide and subsequent revisions. The Guide provides guidance to planners and designers in developing design solutions that meet the needs of a range of users while addressing the context of local conditions and environments. Design guidelines for freeways, arterials, collectors, and local roads, in both urban and rural locations are included as well as guidance for integrated bicycle and pedestrian design. The Guide is organized into ten chapters to cover the entire design process from design philosophy and roadway classification to design parameters and specific guidelines for the safe accommodation of vehicles, cyclists and pedestrians on linear road elements and at intersections. The chapters are: Design Philosophy; Design Controls, Classification and Consistency; Alignment and Lane Configuration; Cross Section Elements; Bicycle Integrated Design; Pedestrian Integrated Design; Roadside Design; Access; Intersections; and Interchanges. Chapter 3 – Alignment and Lane Configuration focuses on the design procedures and domains associated with horizontal and vertical alignment, the coordination of these two design elements and related issues including: cross slopes, lane widening, balance and continuity and specialized traffic lanes such as truck climbing lanes, passing lanes and truck escape ramps.

Geometric Design Guide for Canadian Roads: Chapter 2 - Design Controls, Classification and Consistency

Tue, 07/25/2017 - 14:14
Geometric Design Guide for Canadian Roads: Chapter 2 - Design Controls, Classification and Consistency
by Chiu,M; Clayton,C; Millen,G; et al.
2017.
CA6 ARH_85 2017G22 Ch.02 - REF


The Geometric Design Guide for Canadian Roads contains the current design and human factors research and practices for roadway geometric design. It replaces the 1999 edition of the Guide and subsequent revisions. The Guide provides guidance to planners and designers in developing design solutions that meet the needs of a range of users while addressing the context of local conditions and environments. Design guidelines for freeways, arterials, collectors, and local roads, in both urban and rural locations are included as well as guidance for integrated bicycle and pedestrian design. The Guide is organized into ten chapters to cover the entire design process from design philosophy and roadway classification to design parameters and specific guidelines for the safe accommodation of vehicles, cyclists and pedestrians on linear road elements and at intersections. The chapters are: Design Philosophy; Design Controls, Classification and Consistency; Alignment and Lane Configuration; Cross Section Elements; Bicycle Integrated Design; Pedestrian Integrated Design; Roadside Design; Access; Intersections; and Interchanges. Chapter 2 – Design Controls, Classification and Consistency discusses how design controls such as human factors, speed, design vehicles and sight lines influence geometric design. The chapter also includes guidance for classifying links in a road network to provide for a hierarchical and readily understood road system that properly serves different purposes. The principles of providing consistency in cross section, operating speed and driver workload are outlined in this chapter.

Geometric Design Guide for Canadian Roads: Chapter 1 - Design Philosophy

Tue, 07/25/2017 - 14:14
Geometric Design Guide for Canadian Roads: Chapter 1 - Design Philosophy
by Chiu,M; Clayton,C; Millen,G; et al.
2017.
CA6 ARH_85 2017G22 Ch.01 - REF


The Geometric Design Guide for Canadian Roads contains the current design and human factors research and practices for roadway geometric design. It replaces the 1999 edition of the Guide and subsequent revisions. The Guide provides guidance to planners and designers in developing design solutions that meet the needs of a range of users while addressing the context of local conditions and environments. Design guidelines for freeways, arterials, collectors, and local roads, in both urban and rural locations are included as well as guidance for integrated bicycle and pedestrian design. The Guide is organized into ten chapters to cover the entire design process from design philosophy and roadway classification to design parameters and specific guidelines for the safe accommodation of vehicles, cyclists and pedestrians on linear road elements and at intersections. The chapters are: Design Philosophy; Design Controls, Classification and Consistency; Alignment and Lane Configuration; Cross Section Elements; Bicycle Integrated Design; Pedestrian Integrated Design; Roadside Design; Access; Intersections; and Interchanges. Chapter 1-Design Philosophy provides an introduction to the design objectives, its evolving approach and the design domain concept utilized throughout the Guide. Guidance on benefit cost analysis, value engineering and design exceptions is also provided.

New Technology Uses Renewable Resources to Improve Asphalt Paving and Preservation Sustainability

Tue, 07/25/2017 - 14:14
New Technology Uses Renewable Resources to Improve Asphalt Paving and Preservation Sustainability
by Crews,E; Bowers,JM; Steger,RK; Muncy,DM.
2016.
Proceedings of the Sixth-First Annual Conference of the Canadian Technical Asphalt Association (CTAA): Banff, Alberta.
CA6 AIH___ 2016P22 - MAIN


Results of laboratory evaluations of a new asphalt paving and maintenance technology are introduced. The presented research and development work will show that the technology, which is based on renewable raw materials, provides a number of production and construction benefits, including lowering bitumen and mix temperatures below those typical of WMA paving, widening the weather conditions that currently restrict asphalt paving and preservation operations, and managing strength development through formulation controls. Additionally, the results will show that the technology enables cost-effective binder modification to yield PG-compliant bitumen having broader Useful Temperature Intervals (UTIs) than those achieved with traditional binder modification techniques. This paper will emphasize these and other benefits within the context of application of the technology to the energy-efficient production of durable bitumen with unique performance characteristics.

Customized Municipal Asphalt Specifications - Experience with the First Year of Implementation

Tue, 07/25/2017 - 14:14
Customized Municipal Asphalt Specifications - Experience with the First Year of Implementation
by Uzarowski,L; Henderson,V; Rizvi,R.
2016.
Proceedings of the Sixth-First Annual Conference of the Canadian Technical Asphalt Association (CTAA): Banff, Alberta.
CA6 AIH___ 2016P21 - MAIN


Numerous municipalities in Ontario have observed poor asphalt pavement performance over the last few years, primarily premature cracking and raveling. There was concern that the problems were mainly due to the irresponsible use of Recycle Engine Oil Bottoms (REOB) and Reclaimed Asphalt Pavement (RAP), as well as lean mixes and some mix production issues. Customized asphalt paving specifications including asphalt cement were developed for some of these municipalities. The main changes included restrictions on the modification of asphalt cement and advanced, new laboratory testing. Additional changes in asphalt mix and paving specifications included adding minimum asphalt cement content to Superpave mixes, tightening some of the construction tolerances and steps to control the amount of RAP added to the mixes. This paper presents the main aspects of the customized municipal asphalt specifications and their implementation in five large municipalities in Ontario. Generally, the industry responded well and supplied the material that met the new specified requirements. Significant trends of improved pavement quality were observed. It is considered critical that the new requirements are understood by the Owners, Contractors and Consultants and they are consequently enforced.

It's Not the Asphalt, It's Your Fault: Use of Innovative Paving Practices to Achieve Excellent Pavement Density

Tue, 07/25/2017 - 14:14
It's Not the Asphalt, It's Your Fault: Use of Innovative Paving Practices to Achieve Excellent Pavement Density
by Gilliland,A; Trousil,R.
ENGLISH.
2016.
Proceedings of the Sixth-First Annual Conference of the Canadian Technical Asphalt Association (CTAA): Banff, Alberta.
CA6 AIH___ 2016P20 - MAIN


Insufficient pavement density, whether within the asphalt mat or at a joint is the number one reason a pavement fails before it reaches its design life. There are a number of variables in asphalt production and paving processes that can cause lower than desired density. This paper describes innovative technologies, proper paving practices, and quality control processes used during the Petersburg, Alaska Airport Apron and Taxiway Pavement Rehabilitation Project. The purpose of using these technologies was to ensure consistent mat and joint densities were achieved. Intelligent compaction, use of a material transfer vehicle, infrared joint heating, and warm mix additives were all used on the project. Thermal cameras, intelligent compaction data, and core samples from the mat and joints were used to verify complete rolling patterns, identify thermal segregation (or lack of), and ensure that the infrared joint heater was heating asphalt to target temperatures. These processes, combined with a good quality control program, resulted in a high quality pavement. Mat and joint densities met project specifications and 98 Percent Within Limits (PWL). The maximum allowable bonus for asphalt, density, and joint density was received.

Determination of Mixing and Compaction Temperatures of Modified Asphalt Cements and a Limited Investigation of the Effect on Superpave Volumetric Mix Design Properties

Tue, 07/25/2017 - 14:14
Determination of Mixing and Compaction Temperatures of Modified Asphalt Cements and a Limited Investigation of the Effect on Superpave Volumetric Mix Design Properties
by Brown,AW; Dziedziejko,T; Magisano,F.
2016.
Proceedings of the Sixth-First Annual Conference of the Canadian Technical Asphalt Association (CTAA): Banff, Alberta.
CA6 AIH___ 2016P19 - MAIN


Determining the mixing and compaction temperatures for an asphalt cement is based on the equiviscous temperature that is typically determined by the rotational viscometer. The purpose of determining the mixing and compaction temperatures is to normalize the effect of asphalt binder stiffness on mixture volumetric properties for laboratory prepared specimens. While this procedure has worked well for neat asphalt cements (i.e., asphalt binders that have a Useful Temperature Interval, UTI of < 92°C), with the more highly modified asphalt cement being used today, the rotational viscometer tends to yield excessively high mixing and compaction temperatures. A study was done by members of the Ontario Hot Mix Producers Association to determine the mixing and compaction temperatures by the rotational viscometer and also by the Dynamic Shear Rheometer (DSR) Steady Shear Flow Procedure as recommended by NCHRP Report 648. Based on these results, selected binders were combined with aggregates with two different lithologies to determine the effect of the different mixing and compaction temperatures on the mixture volumetric properties for laboratory specimens prepared using the Superpave mix design methodology.

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