Download or read book Mixing and Compaction Temperatures of Asphalt Binders in Hot mix Asphalt written by Randy Clark West and published by Transportation Research Board National Research. This book was released on 2010 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report identifies improved test methods for determining laboratory mixing and compaction temperatures of modified and unmodified asphalt binders. The report will be of immediate interest to materials engineers in state highway agencies and the hot-mix asphalt (HMA) construction industry.
Download or read book Mixing and Compaction Temperatures of Asphalt Binders in Hot Mix Asphalt written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NCHRP Report 648 written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Selection of Mixing and Compaction Temperatures for Hot Mix Asphalt Mixtures Produced with Modified Binders written by and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT The primary objective of this research study is to develop a protocol to determine mixing and compaction temperatures for hot mix asphalt mixtures produced with modified asphalts. Presently no specific guidelines exist for contractors to follow. The research plan of this study was divided into three components. The first component focused on finding binder shear properties that best relate to mixture mixing and compaction properties, the second component on developing a protocol to determine the zero shear viscosity and the third to assess the effect of zero shear viscosity on performance related properties. The first component involved shear testing of binders, mixture compaction and statistical analysis of binder data. The experimental plan for included mixing and compaction of HMA and analysis of the volumetric data obtained from the Superpave Gyratory Compactor (SGC). Binder testing was carried out using the Dynamic Shear Rheometer (DSR) to obtain viscosity data to measure shear susceptibility of non-Newtonian modified binders tested. The second component was conducted to include detailed viscosity testing of all binders in the research study. A new procedure to measure the shear dependency of modified binders using the Rotational Viscometer (RV) was developed and testing was carried out at varying shear rate and multiple temperatures. The results indicated that as the shear rate decreases, a better correlation is obtained with mixture volumetric properties. The research was continued to develop a procedure to measure zero shear viscosity (ZSV). The Cross-Williamson's model was selected and developed to measure ZSV. Mixing and compaction temperatures could then be determined using ZSV data in a viscosity temperature profile. The new temperatures determined for all binders in the project were used to validate the approach. The validation resulted in all binders achieving required volumetric properties specification and vindicating the ZSV approach. The third and final component involved testing of HMA to observe effect of lowered temperatures on the performance of the HMA. The specimens were tested for moisture damage using the Modified-Lottman Test, for rutting potential using the energy indices and Pressure Distribution Analyzer (PDA). All mixtures passed both the performance tests and validated the ZSV approach.
Download or read book Investigation of the Performance of Neat and Modified Asphalt Binders written by Yalan Tang and published by . This book was released on 2006-10-15 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Special Mixture Design Considerations and Methods for Warm Mix Asphalt written by and published by Transportation Research Board. This book was released on 2012 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 714: Special Mixture Design Considerations and Methods for Warm-Mix Asphalt: A Supplement to NCHRP Report 673: A Manual for Design of Hot-Mix Asphalt with Commentary presents special mixture design considerations and methods used with warm-mix asphalt. NCHRP Report 714 is a supplement to NCHRP Report 673: A Manual for Design of Hot-Mix Asphalt. All references to chapters in NCHRP Report 714 refer to the corresponding chapters in NCHRP Report 673.
Download or read book Mix Design Practices for Warm Mix Asphalt written by Ramon Francis Bonaquist and published by Transportation Research Board. This book was released on 2011 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 691: Mix Design Practices for Warm-Mix Asphalt explores a mix design method tailored to the unique material properties of warm mix asphalt technologies. Warm mix asphalt (WMA) refers to asphalt concrete mixtures that are produced at temperatures approximately 50°F (28°C) or more cooler than typically used in the production of hot mix asphalt (HMA). The goal of WMA is to produce mixtures with similar strength, durability, and performance characteristics as HMA using substantially reduced production temperatures. There are important environmental and health benefits associated with reduced production temperatures including lower greenhouse gas emissions, lower fuel consumption, and reduced exposure of workers to asphalt fumes. Lower production temperatures can also potentially improve pavement performance by reducing binder aging, providing added time for mixture compaction, and allowing improved compaction during cold weather paving. Appendices to NCHRP Report 691 include the following. Appendices A, B, and D are included in the printed and PDF version of the report. Appendices C and E are available only online.
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:
Download or read book Mixing and Compaction Temperatures of Asphalt Binders in Hot mix Asphalt written by Randy Clark West and published by Transportation Research Board National Research. This book was released on 2010 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report identifies improved test methods for determining laboratory mixing and compaction temperatures of modified and unmodified asphalt binders. The report will be of immediate interest to materials engineers in state highway agencies and the hot-mix asphalt (HMA) construction industry.
Download or read book Laboratory Evaluation of Warm Mix Asphalt Prepared Using Foamed Asphalt Binders written by Ayman W. Ali and published by . This book was released on 2010 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warm Mix Asphalt (WMA) is a name given to different technologies that have the common purpose of reducing the viscosity of the asphalt binders. This reduction in viscosity offers the advantage of producing asphalt-aggregate mixtures at lower mixing and compaction temperatures, and subsequently reducing energy consumption and pollutant emissions during asphalt mix production and placement. WMA technologies can be classified into two groups. The first group reduces the asphalt binders' viscosity through the addition of organic or chemical additives, while the second group reduces the viscosity of the asphalt binders through the addition of water. The latter has received increased attention in Ohio since it does not require the use of costly additives. In spite of the above-mentioned advantages for WMA mixtures, many concerns have been raised regarding the susceptibility of this material to moisture-induced damage and permanent deformation due to the reduced temperature level used during WMA production. Therefore, this study was conducted to develop a laboratory procedure to produce WMA mixtures prepared using foamed asphalt binders (WMA-FA), and to evaluate their performance in comparison to conventional Hot Mix Asphalt (HMA). This study involved two types of aggregates (natural gravel and crushed limestone) and two types of asphalt binders (PG 64-22 and PG 70-22M). A laboratory scale asphalt binder foaming device called WLB10, produced by Wirtgen, Inc., was used to foam the asphalt binders. The aggregate gradation met the Ohio Department of Transportation (ODOT) Construction and Materials Specification (C&MS) requirements for Item 441 Type 1 Surface Course for Medium Traffic. The resistance of WMA-FA and HMA mixtures to moisture-induced damage was measured using AASHTO T-283, and the resistance to permanent deformation was measured using the Asphalt Pavement Analyzer (APA) and the Simple Performance Test (SPT). Based on the experimental test results and the subsequent analyses findings, the following conclusions were made: [1] WMA-FA mixtures are more workable and easily compacted than HMA mixtures even though they are produced at lower mixing and compaction temperatures; [2] WMA-FA mixtures are slightly more susceptible to moisture damage than HMA mixtures. However, the difference is statistically insignificant. Therefore, if designed properly, both mixtures are expected to meet ODOT's minimum TSR requirement for the proposed traffic level; [3] WMA-FA mixtures, especially those prepared using gravel aggregates and unmodified asphalt binders are more prone to rutting than the corresponding HMA mixtures. Therefore, it is recommended to include the APA test as part of the WMA mix design procedure to ensure satisfactory performance for rutting.
Download or read book Mixing and Compaction Temperatures for Hot Mix Asphalt Concrete written by Yetkin Yildirim and published by . This book was released on 2000 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Short term Aging of Hot Mix Asphalt written by Timothy Aschenbrener and published by . This book was released on 1994 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Michigan Test Road written by Michigan. State Highway Department and published by . This book was released on 1942 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methodology for Determining Compaction Temperatures for Modified Asphalt Binders written by Kevin D. Stuart and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The equiviscous principle, which is based on the viscosities of an asphalt binder, determines the compaction temperature to be used during asphalt mixture design. When this principle is used, theoretically, all asphalt binders should provide the same optimum asphalt binder content at a 4-percent design air-void level when all other variables, such as compaction effort and aggregate gradation, are held constant. The compaction temperature determined by this principle is also used by asphalt paving contractors as an indicator of how workable a mixture should be during construction. The equiviscous principle was developed using unmodified asphalt binders. For some polymer-modified asphalt binders, the equiviscous principle gives a compaction temperature that is significantly higher than what is needed. Excessively high temperatures may damage the asphalt binder, generate fumes, cause asphalt binder draindown, and may lead to a low asphalt binder content in some mixtures. The objective of this study was to find an asphalt binder or mastic property that can provide appro-priate compaction temperatures for use during asphalt mixture design. The data collected in this study strongly suggest that there is not a single viscosity range that can be used for all asphalt binders. It is recommended that the current standardized asphalt binder viscosity range be used for unmodified asphalt binders. For polymer-modified asphalt binders, this study recommends a different viscosity range. The allowable compaction temperature range was based on obtaining an air-void range of 3.5 to 4.5 percent after each mixture was compacted using the Superpave gyratory compactor. This tolerance provided a relatively wide allowable compaction temperature range. Mechanical properties were not measured. The allowable compaction temperature ranges for these mixtures could be narrower if they were to be based on obtaining the same mechanical properties. Mechanical properties could be more sensitive than density to differences in age-hardening that occur during short-term oven aging and compaction. Additional studies are needed to determine this.
Download or read book Improved Mix Design Evaluation and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content written by Randy Clark West and published by Transportation Research Board. This book was released on 2013 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 752: Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content describes proposed revisions to the American Association of State Highway and Transportation Officials (AASHTO) R 35, Superpave Volumetric Design for Hot Mix Asphalt, and AASHTO M 323, Superpave Volumetric Mix Design, to accommodate the design of asphalt mixtures with high reclaimed asphalt pavement contents.
Download or read book Mechanical Properties of Warm Mix Asphalt Prepared Using Foamed Asphalt Binders written by Ala R. Abbas and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hot mix asphalt (HMA) is a mixture containing aggregates and asphalt binders prepared at specified proportions. The aggregates and asphalt binder proportions are determined through a mix design procedure such as the Marshall Mix Design or the Superpave Mix Design methods. Overall, the goal of determining such proportions is to establish an HMA mixture that will meet specific performance criteria. In addition, it is imperative to ensure that the asphalt binder will fully coat the aggregates and that the resulting mixture is workable and compactable. In order to ensure sufficient aggregate drying and coating, both the asphalt binder and the aggregates are heated to elevated temperatures ranging between 300oF and 325oF. The use of such high temperatures would result in lowering the viscosity of the asphalt binder which is the main factor affecting the coating and workability of asphalt mixtures. In recent years, a new group of technologies have been introduced to the United States that allow producing asphalt mixtures at temperatures 30 to 100oF lower than what is used in HMA. This group of technologies is commonly referred to as Warm Mix Asphalt (WMA). They are promoted as environmentally friendly green alternatives to HMA mixtures as they produce lower greenhouse gas emissions. This new group of technologies aims at reducing the viscosity of the asphalt binder through the addition of organic or chemical additives or by introducing cool water into the heated molten asphalt under controlled temperature and pressure conditions, resulting in so-called foamed asphalt binder. As a consequence, lower temperatures are needed during production for the asphalt binder to be absorbed by the aggregates.
