Download or read book Initial Performance Assessment for Implementation of Hot Mix Asphalt Containing Recycled Asphalt Shingles in Oregon written by Faisal Ahmed Samoo and published by . This book was released on 2011 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis documents the evaluation of the initial performance of pavement containing recycled asphalt shingles (RAS) in Oregon. The research was funded by the Oregon Department of Transportation (ODOT) and the Federal Highway Administration and was conducted at Oregon State University. The key objectives of this thesis are to document the state-of-the-practice for implementation of recycled asphalt shingles in hot mix asphalt (HMA) mixtures, and to evaluate the initial field and laboratory performance of mixtures containing RAS. Recent oil price increases, coupled with environmental impacts has encouraged industry to use materials containing asphalt binder, such as asphalt shingles as a partial replacement of virgin materials in the construction of bituminous pavement. Residential home reroofing projects generate RAS as does the asphalt shingle manufacturing industry as a waste product at a rate of approximately 11 million tons per year nationwide. Disposal of these materials ordinarily involves discarding the materials in landfills. However, since these shingles contain asphalt binder, many states and asphalt pavement contractors have made efforts to incorporate these materials into asphalt pavements. Asphalt shingles are produced with asphalt binders that have substantially higher stiffness than paving grade asphalt binders. With increased stiffness comes increased brittleness. Consequently, incorporating RAS into hot mix asphalt may expose the pavement to an increased likelihood of low temperature cracking and fatigue cracking unless modifications are made to the mixtures to compensate for increased stiffness due to the RAS binder. House Bill 2733, proposed before the Oregon Legislative Assembly in 2009, would have required ODOT to use up to 5% RAS in HMA. However, inclusion of RAS in HMA raised concerns within the agency with regard to the potential for reduction in pavement performance ultimately leading to increased costs due to early failures. Consequently, considering these concerns the legislation on this bill was postponed pending completion of research to investigate the performance of pavement containing RAS in Oregon pavements. As a result, ODOT sponsored preliminary research on use of RAS in HMA in 2009 and subsequently through the research project described herein. The research work described herein was separated into three distinct but interconnected tasks. The first involved conducting a detailed literature review to gain an understanding of the state-of-the-practice for successful implementation of RAS in pavements. Emphasis during this effort was placed on selection of the virgin binder grade to offset the effects of increased stiffness due to incorporation of RAS binder, batching and mixing procedures for inclusion of RAS in HMA mixtures, ignition oven calibration factors for mixtures containing RAS, and quality control/quality assurance procedures for pavements built with RAS mixtures. There exists a substantial body of literature covering use of recycled asphalt pavement (RAP) as a partial replacement of virgin materials in HMA pavements. Due to many similarities of RAP and RAS, many of the documents reviewed covered only RAP, but with the aim of extending the technologies used for RAP mixtures to those containing RAS or RAS and RAP. The second task involved conducting laboratory investigations to verify the practicality and effectiveness of procedures found in the literature for batching and mixing materials containing RAS and/or RAP and RAS. Finally, the third task involved investigations of performance of two pavements containing RAP and RAS constructed as pilot projects. The investigations involved an assessment of field performance and laboratory tests on samples obtained from the two pavements. For comparison purposes, the same investigations were performed on pavements and samples from pavements that contained RAP but no RAS. These were constructed adjacent to, and at the same time as, the pavements with RAP and RAS. Based on the findings from the literature review, this thesis contains recommendations for: 1) selection of a virgin binder grade when RAP and/or RAS is used in an HMA mixture; 2) a procedure for effectively and efficiently extracting and recovering asphalt binder from RAS; 3) batching and mixing procedures for manufacturing laboratory test specimens containing RAS; 4) a method for determining ignition over calibration factors for mixtures containing RAS; and 5) quality control/quality assurance procedures for pavements built with RAS mixtures. The recommended batching and mixing procedure was verified through laboratory investigations while ongoing research is in the process of verifying the remaining procedures. Laboratory investigations involving dynamic modulus testing and comparative analyses of RAP-only mixtures (control mixtures) versus RAP and RAS mixtures indicated a trend of reduced dynamic modulus due to the addition of RAS in the mixture on both pilot projects. However, when the mixtures were compared at a 95 percent confidence level, a significant difference was found for only one of the two projects. This reduction in dynamic modulus was likely due to the softening of blended binder and the increased air voids in the mixtures containing RAS. In addition, fatigue testing and comparative analyses using phenomenological and dissipated energy approaches indicated that there was no significant difference in fatigue resistance of the RAP-only mixture versus the RAP and RAS mixture at a 95 percent confidence level. Assessment of field performance through visual inspections of the pavements built with mixtures containing RAS revealed no low temperature cracking following the first winter season in service. Nor did the inspections reveal any fatigue cracking. Although these inspections occurred within 8 months of construction of the pavements, the findings provide encouraging early-life performance of the mixtures.

Download or read book Performance Evaluation of Recycled Asphalt Shingles RAS in Hot Mix Asphalt HMA written by Riyad-UL. Islam and published by . This book was released on 2011 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today, a large quantity of waste is generated from the replacement of residential and commercial roofs. Many of the roofs being upgraded with previously constructed from asphalt shingles. Recycled Asphalt Shingles (RAS) contain nearly 30% of asphalt cement by mass, which can be a useful additive to asphalt pavements. In addition, shingles can offer significant potential savings through recycling and recovery as a construction material in flexible pavement. Currently, one and a half million tons of roofing shingle waste is generated each year in Canada related to the replacement of residential and commercial roofs and 90% of this valuable material is sent to landfills. If engineered properly, the addition of RAS into Hot Mix Asphalt (HMA) can provide significant benefits. The University of Waterloo's Centre for Pavement and Transportation Technology (CPATT) is committed to working with public and private sector partners to develop sustainable technologies for the pavement industry. Using RAS in HMA can lead to economical, environmental and social benefits. Examples of which are reduced waste going to landfills and a reduction in the quantity of virgin material required. This research has involved the Ontario Centres of Excellence (OCE) and Miller Paving Limited. It was conducted to evaluate the performance of HMA containing RAS in both field and laboratory tests.

Download or read book Using Recycled Asphalt Shingles with Warm Mix Asphalt Technologies written by Randy Clark West and published by . This book was released on 2018 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Blending Issues of Hot and Warm Mix Asphalt Containing Recycled Asphalt Pavement and Recycled Asphalt Shingle written by Sheng Zhao (Writer on pavements) and published by . This book was released on 2014 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current tendency in paving industry is to increase the use of recycled asphalt pavement (RAP) and recycled asphalt shingle (RAS). However, one of the reasons that limit the high recycled amount is the unknown blending between virgin and RAP/RAS binders. A series of studies were conducted in this dissertation to address blending issues in warm mix asphalt (WMA) and hot mix asphalt (HMA) containing RAP and RAS, in terms of evaluation of recycled binder mobilization, binder homogeneity and WMA effects on blending. Partial blending was observed in RAS mixtures and the most efficient blending occurred at approximately 5% RAS by weight. Increasing time led to a better RAS binder mobilization, while aggregate size and temperature in a certain range showed limited effects. A new parameter derived from gel permeation chromatography (GPC), large molecular size percentage [LMS(%)] related to binder molecular weight distribution, was developed to differentiate virgin and RAP/RAS binders as well as their blends, based on which a method was developed to quantify the recycled binder mobilization rate. A two-layer model based on atomic force microscopy (AFM) scanning was developed to evaluate RAS and virgin binder blending. The two binders were found to be “mixing” but not “blending” in a mixing zone of 25 to 30 micrometer. Staged extraction method used to evaluate asphalt binder homogeneity was validated with trichloroethylene (TCE) as the most effective solvent. A non-equal-time staged extraction method was proposed, in conjunction with LMS(%), to quantify binder homogenization after mechanical mixing and diffusion. Different blending scenarios of RAP/RAS mixes were proposed and validated. It was found that diffusion could be accomplished within mixture storage time for both WMA and HMA containing RAP, while blending in RAS mix was limited. WMA additives yielded mixes with higher blending ratios than control mix produced at 135oC, but lower than hot mix produced at 165oC. Laboratory foaming yielded a higher blending ratio, indicating foamed WMA may improve blending. Rutting might still be a concern for WMA-high RAP mixtures while fatigue concern may not exist. WMA-high RAP mixtures showed satisfactory moisture resistance. Blending effects on performance still needs further investigation.

Download or read book Innovative Assessment Tests and Indicators for Performance based Asphalt Mix Design written by Hamza Alkuime and published by . This book was released on 2019 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: Asphalt mixes are designed to provide adequate resistance to various distresses including cracking, rutting, and moisture damage. Recently, more efforts are directed towards including performance assessment tests during the design and production of asphalt mixes. Performance-Engineered Mix Design (PEMD) or Balanced Mix Design (BMD) is a new and innovative design approach that incorporates performance assessment tests to optimize the design of asphalt mixes to provide adequate performance. Although transportation agencies are motivated to implement the PEMD approach, several research knowledge gaps and concerns need to be addressed before PEMD successful implementation. This research study aims to advance, develop, and implement performance-engineered design approach and specifications to extend the service life of asphalt pavements.The first phase of this research developed and evaluated a new and innovative monotonic cracking performance indicator called Weibull Cracking Resistance Index (WeibullCRI). The proposed indicator describes the entire load-displacement curve, which overcomes the limitations of the existing performance indicators. First, WeibullCRI was examined using an extensive laboratory evaluation of 16 different asphalt mixes. The results indicated that WeibullCRI was sensitive to variation in binder content and binder PG and the results were in good agreement with the expected cracking resistance based on the composition of the studied mixes. In addition, WeibullCRI had low variability in test results and higher number of various statistical groups. Next, the applicability of WeibullCRI as a unified approach to analyze the results of various monotonic assessment tests was investigated using data generated by other researchers and reported in the literature. The results indicated that WeibullCRI is able to interpret the testing results of various monotonic performance assessment tests (i.e., IDT- intermediate temperature, Semi-Circle Bending [SCB]- intermediate temperature, SCB-low temperature, Disk-Shaped Compact Tension [DCT], and Simple Punching Shear Test [SPST]) and various displacement measurement methods (i.e., actuator vertical displacement and Crack Mouth Opening Displacement [CMOD]). WeibullCRI was also sensitive to variation in test conditions (i.e., specimen notch depth, thickness, and air void content) and mix composition proportions (i.e., binder content, binder grade, aggregate type, NMAS, aging, rejuvenator dosages, and Recycled Asphalt Pavement [RAP] materials).The second phase of this study reviewed and evaluated the current monotonic cracking performance assessment tests and indicators including the developed WeibullCRI used to assess asphalt mix resistance to cracking. In this phase, the testing requirements of various test standards, key publications, concepts, calculation methods, physical meaning, and advantages and disadvantages of various performance indicators were reviewed. Then, the study investigated the validity of the most promising testing standards and indicators. Three testing standards and 12 performance indicators were considered. Several aspects were examined including 1) investigate the fundamental meaning of the variation in the load-displacement curve in terms of the change in mix resistance to cracking, 2) sensitivity of performance indicators to mix compositions, 3) variability in test results, 4) number of various statistical groups, 5) correlation between various performance indicators, 6) direct correlation between laboratory results of monotonic performance tests and indicators with the observed field cracking, and 7) ability to develop PEMD specifications. A comprehensive laboratory investigation was conducted using 33 different asphalt mixes included six Laboratory Mixed-Laboratory Compacted (LMLC) and 10 Plant Mixed-Laboratory Compacted (PMLC) asphalt mixes, and 17 field projects with known cracking performance. The results showed that WeibullCRI calculated from the IDT test to have the lowest test variability, maximum number of Tukey's honestly significant difference (HSD) groups, and have excellent correlation with cyclic cracking resistance assessment indicators as compared to the other monotonic performance indicators. In addition, the results demonstrated that there was no direct correlation between all monotonic performance indicators and the observed field cracking performance, therefore an alternative approach was proposed, evaluated, and validated to develop performance thresholds for the selected performance indicators. Three pass/fail cracking performance thresholds were proposed for WeibullCRI to distinguish between asphalt mixes with good, fair, and poor cracking resistance using the proposed approach.The third phase of this study focused on the development and evaluation of a new cyclic cracking assessment test called Multi-Stage Semi-circle bending Dynamic (MSSD). The test offers advantages over the available monotonic and dynamic cracking assessment tests and addresses major concerns to implement the PEMD (i.e., performance test validity, complex specimen preparation, and testing time). The developed MSSD test simulates the repeated loading (cyclic) in a reasonable testing time (less than 9 hours per test regardless of mix type), has a fixed loading sequence that works for mixes with different characteristics (e.g., mix composition, percent air void content, thickness, etc.), and utilizes testing equipment and specimen geometry similar to that used in monotonic tests. The laboratory evaluation results showed that the proposed test and its derived performance indicators were sensitive to mix composition and had lower variability compared to other dynamic tests. In addition, the MSSD performance indicators correlated well with the observed cracking performance in the field and were able to distinguish between projects with good and poor resistance to cracking. Based on the evaluation results, three pass/fail cracking performance thresholds were proposed to distinguish between asphalt mixes with good, fair, and poor resistance to cracking.The fourth phase of this research examined the most promising tests and performance indicators to evaluate the resistance of asphalt mixtures to rutting. Two tests (i.e., Hamburg Wheel Tracking test [HWTT], and Asphalt Pavement Analyzer [APA] rut test) and three rutting performance indicators (i.e., HWTT rut depth after 15,000 passes [HWTT15000], HWTT rut depth at 20,000 passes [HWTT20000], and APA rut depth after 8,000 cycles [APA8000]) were considered. An intensive laboratory investigation was conducted that included six LMLC, 10 PMLC, and field cores extracted from 17 field projects. The research findings showed that both HWTT and APA rut test provided similar rutting assessment for the evaluated mixes. The study recommended using the HWTT over the APA rut test since HWTT can be also used to assess the resistance of asphalt mixtures to moisture damage to moisture damage. Also, the study recommended using HWTT15000 over HWTT20000 as a performance indicator since it requires less testing time.The final phase of this research provided recommendations of the best testing standards, performance indicators, and performance specifications to assess asphalt mix resistance to cracking and rutting. In addition, it provided guidelines to demonstrate the use of the proposed tools during the design and/or production of asphalt mixes. It also proposed standards testing procedures for the newly developed WeibullCRI performance indicator and MSSD test.

Download or read book Application of Reclaimed Asphalt Pavement and Recycled Asphalt Shingles in Hot mix Asphalt National and International Perspectives on Current Practice Papers from a Workshop written by and published by . This book was released on 2014 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB’s Transportation Research Circular E-C188: Application of Reclaimed Asphalt Pavement and Recycled Asphalt Shingles in Hot-Mix Asphalt: National and International Perspectives on Current Practice summarizes papers and presentations presented at a workshop that took place on January 12, 2014 at the TRB 93rd Annual Meeting. The workshop explored material characterization and field validation for short- and long-term performance of asphalt mixtures containing reclaimed asphalt pavement and recycled asphalt shingles." -- Publisher's note.

Download or read book Performance Evaluation of Aged Asphalt Mix for Hot In Place Recycling written by Bin Yu and published by . This book was released on 2015 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite increasing application, limited knowledge is known of in situ and laboratory properties of asphalt mixes placed through hot in-place recycling (HIR). This study conducted a preliminary investigation to inspect the individual and joint effects of binder (aged or rejuvenated) and gradation (decayed or normal) on respective performance indicators. Three mixes were designed and the properties were determined, including mix A collected from aged asphalt pavement, mix B designed with the same gradation of mix A but using virgin materials, and mix C designed with the initial construction aggregate gradation of the aged pavement section using virgin materials. The experimental program was carried out at the binder/aggregate, mortar and mix levels. The binder property, aggregate quality, and gradation of mix A were changed compared to the initial design, and the proper dosage of rejuvenator is able to restore the binder properties largely except for ductility. Asphalt mortars of mixes A and B were prepared and submitted for repeated shear at constant height (RSCH) and frequency sweep at constant height (FSCH) tests and found that the former has a better rutting resistance in terms of the Gv (viscous component of creep stiffness) and complex shear modulus G*, whereas poorer low-temperature and fatigue performances in terms of the glassy modulus G*g and NP20. At the mix level, master curves of the three mixes were developed by dynamic modulus tests and revealed disparate viscoelastic properties, of which mix C is mostly desired. Binder aging and gradation decay work contradictorily, determining flow number test results so that mixes A and C have close and higher flow number values than mix B. Fatigue and low-temperature fracture properties were evaluated by semi-circular bending tests and indicated the poorest performance for mix A because of binder aging and gradation decay.

Download or read book Performance of Recycled Asphalt Shingles in Hot Mix Asphalt written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: State highway agencies are increasingly intersted in using recycled asphalt shingles (RAS) in hot mix asphalt (HMA) applications, yet many agencies share common questions about the effect of RAS on the performance of HMA. Previous research has allowed for only limited laboratory testing and field surveys. The complexity of RAS materials and lack of past experiences led to the creation of Transportation Pooled Fund (TPF) Program TPF-5(213). The primary goal of this study is to address research needs of state DOT and environmental officials to determine the best practices for the use of recycled asphalt shingles in hot-mix asphalt applications. Agencies participating in the study include Missouri (lead state), California, Colorado, Illinois, Indiana, Iowa, Minnesota, Wisconsin, and the Federal Highway Administration. The agencies conducted demonstration projects that focused on evaluating different aspects (factors) of RAS that include RAS grind size, RAS percentage, RAS source (post-consumer versus post-manufactured), RAS in combination with warm mix asphalt technology, RAS as a fiber replacement for stone matrix asphalt, and RAS in combination with ground tire rubber. Field mixes from each demonstration project were sampled for conducting the following tests: dynamic modulus, flow number, four-point beam fatigue, semi-circular bending, and binder extraction and recovery with subsequent binder characterization. Pavement condition surveys were then conducted for each project after completion. The demonstration projects showed that pavements using RAS alone or in combination with other cost saving technologies (e.g., WMA, RAP, GTR, SMA) can be successfully produced and meet state agency quality assurance requirements. The RAS mixes have very promising prospects since laboratory test results indicate good rutting and fatigue cracking resistance with low temperature cracking resistance similar to the mixes without RAS. The pavement condition of the mixes in the field aft

Download or read book Performance of Recycled Asphalt Shingles in Hot Mix Asphalt written by R. Christopher Williams and published by . This book was released on 2013 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: State highway agencies are increasingly intersted in using recycled asphalt shingles (RAS) in hot mix asphalt (HMA) applications, yet many agencies share common questions about the effect of RAS on the performance of HMA. Previous research has allowed for only limited laboratory testing and field surveys. The complexity of RAS materials and lack of past experiences led to the creation of Transportation Pooled Fund (TPF) Program TPF-5(213). The primary goal of this study is to address research needs of state DOT and environmental officials to determine the best practices for the use of recycled asphalt shingles in hot-mix asphalt applications. Agencies participating in the study include Missouri (lead state), California, Colorado, Illinois, Indiana, Iowa, Minnesota, Wisconsin, and the Federal Highway Administration. The agencies conducted demonstration projects that focused on evaluating different aspects (factors) of RAS that include RAS grind size, RAS percentage, RAS source (post-consumer versus post-manufactured), RAS in combination with warm mix asphalt technology, RAS as a fiber replacement for stone matrix asphalt, and RAS in combination with ground tire rubber. Field mixes from each demonstration project were sampled for conducting the following tests: dynamic modulus, flow number, four-point beam fatigue, semi-circular bending, and binder extraction and recovery with subsequent binder characterization. Pavement condition surveys were then conducted for each project after completion. The demonstration projects showed that pavements using RAS alone or in combination with other cost saving technologies (e.g., WMA, RAP, GTR, SMA) can be successfully produced and meet state agency quality assurance requirements. The RAS mixes have very promising prospects since laboratory test results indicate good rutting and fatigue cracking resistance with low temperature cracking resistance similar to the mixes without RAS. The pavement condition of the mixes in the field after two years corroborated the laboratory test results. No signs of rutting, wheel path fatigue cracking, or thermal cracking were exhibited in the pavements. However, transverse reflective cracking from the underlying jointed concrete pavement was measured in the Missouri, Colorado, Iowa, Indiana, and Minnesota projects.

Download or read book Quantitative Evaluation of Low temperature Performance of Sustainable Asphalt Mixtures and Binders Containing Recycled Asphalt Shingles RAS and Rejuvenators written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Evaluations of HMA Containing Reclaimed Asphalt Pavement and Reclamed Asphalt Shingles written by Jennifer Foxlow and published by . This book was released on 2011 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Eco efficient Pavement Construction Materials written by Fernando Pacheco-Torgal and published by Woodhead Publishing. This book was released on 2020-01-18 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eco-efficient Pavement Construction Materials acquaints engineers with research findings on new eco-efficient pavement materials and how they can be incorporated into future pavements. Divided into three distinctive parts, the book emphasizes current research topics such as pavements with recycled waste, pavements for climate change mitigation, self-healing pavements, and pavements with energy harvesting potential. Part One considers techniques for recycling, Part Two reviews the contribution of pavements for climate change mitigation, including cool pavements, the development of new coatings for high albedo targets, and the design of pervious pavements. Finally, Part Three focuses on self-healing pavements, addressing novel materials and design and performance. Finally, the book discusses the case of pavements with energy harvesting potential, addressing different technologies on this field. Offers a clear and concise lifecycle assessment of asphalt pavement recycling for greenhouse gas emission with temporal aspects Applies key research trends to green the pavement industry Includes techniques for recycling waste materials, the design of cool pavements, self-healing mechanisms, and key steps in energy harvesting

Download or read book Health Effects of Occupational Exposure to Asphalt written by Mary Ann Stromberg Butler and published by . This book was released on 2001 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: An evaluation of the health effects and other relevant data since pub. of the 1977 NIOSH "Criteria for a Recommended Standard: Occupational Exposure to Asphalt Fumes." Includes an assessment of chemistry, health, and exposure data from studies in animals and humans exposed to raw asphalt, paving and roofing asphalt fume condensates, and asphalt-based paints. Will serve as to identify future research to reduce occupational exposures to asphalt. Chapters: no. of workers potentially exposed; physical and chemical properties; exposure; human health effects; experimental studies; research needs; uses and applications; summary of occupational exposure data; and respirators.

Download or read book Performance Specifications for Asphalt Mixtures written by Jonathan Callans and published by . This book was released on 2016 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Urban Stormwater Management in the United States written by National Research Council and published by National Academies Press. This book was released on 2009-03-17 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rapid conversion of land to urban and suburban areas has profoundly altered how water flows during and following storm events, putting higher volumes of water and more pollutants into the nation's rivers, lakes, and estuaries. These changes have degraded water quality and habitat in virtually every urban stream system. The Clean Water Act regulatory framework for addressing sewage and industrial wastes is not well suited to the more difficult problem of stormwater discharges. This book calls for an entirely new permitting structure that would put authority and accountability for stormwater discharges at the municipal level. A number of additional actions, such as conserving natural areas, reducing hard surface cover (e.g., roads and parking lots), and retrofitting urban areas with features that hold and treat stormwater, are recommended.

Download or read book A Manual for Design of Hot Mix Asphalt with Commentary written by and published by Transportation Research Board. This book was released on 2011 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Superpave Mix Design written by Asphalt Institute and published by . This book was released on 2001-01-01 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: