Download or read book Evaluation of Mix Ingredients on the Performance of Rubber modified Asphalt Mixtures written by Hossein B. Takallou and published by . This book was released on 1987 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rubber-modified asphalt pavements have been used in Sweden and the United States since the 1970's. In these applications ground recycled tire particles (1/4 inch minus) are added to a gap-graded aggregate and then mixed with hot asphalt cement. The benefits of adding rubber to the mix include increased skid resistance under icy conditions, improved flexibility and crack resistance, elimination of solid waste, and reduced traffic noise. The major disadvantage of these rubber-modified mixes is their high cost in relation to conventional asphaltic concrete pavements. This research project consisted of a laboratory study of mix properties as a function of variables such as rubber gradation and content, void content, aggregate gradation, mix process, temperature, and asphalt content. Twenty different mix combinations were evaluated for diametral modulus and fatigue at two different temperatures ( -6°C, +10°C). Also, five different mix combinations were evaluated for static creep and permanent deformation. Layered theory was used to evaluate the effects of mixture variations on pavement life. The resulting information was used to develop guidelines for use of rubber asphalt mixes in United States road systems. The findings of the field survey indicate that the rubber-modified asphalt mixture is more susceptible than the conventional mixtures to preparation and compaction problems when adverse weather or equipment problems occur. However, with adequate equipment and favorable weather conditions, the rubber-modified asphalt mixture placement is similar to conventional mixture placement. The field study also indicates that stopping distances can be reduced 20 percent for the rubber-modified pavements in icy conditions. In view of the significant reductions in wintertime stopping distances under icy or frosty road surface conditions, the use of coarse rubber in asphalt pavements should be seriously considered. This is particularly true for areas such as bridge decks, on and off freeway ramps or insulated roadway sections. The findings of the laboratory study indicate that the rubber gradation and content, aggregate gradation, and use of surcharge during sample preparation have considerable effect on modulus and fatigue life of the mix. The results of static creep and permanent deformation tests indicate that the rubber asphalt mixes had low stability and high elasticity. Also, due to greater allowable tensile strain in rubber-modified mixtures, the thickness of the modified mixture can be reduced, using a layer equivalency of 1.4 to 1.0.

Download or read book Effect of Mix Ingredients on Performance of Rubber Modified Asphalt Mixtures written by H. B. Takallou and published by . This book was released on 1985 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the results of field performance surveys and laboratory testing programs aimed at identifying the critical factors in designing and constructing rubber-modified asphalt pavements using a content of 2 to 3% of coarse (1/4 inch to #40 sieve) ground tire rubber. The benefits of adding rubber in this size range to asphalt paving mixes are those of increasing traction and reducing stopping distances.

Download or read book Effect of Mix Ingredients on the Behavior of Rubber modified Asphalt Mixtures written by H. B. Takallou and published by . This book was released on 1985 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mixture Desigh sic and Performance Prediction of Rubber modified Asphalt in Ohio written by Robert Y. Liang and published by . This book was released on 1998 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mixture design and performance characteristics of crumb rubber modified asphalt concretes were investigated in this research project to meet the requirements of the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991, which has required each State to incorporate scrap tire rubber into its asphalt paving materials. Specifically, the objectives of this research encompass the following: (i) investigation of the rheological properties of asphalt-rubber binder to determine optimum content of crumb rubber; (ii) development of optimum mix design for various applications, including both wet and dry mix processes; (iii) characterization of mechanical properties of recommended paving mixtures, including resilient modulus, fatigue cracking behavior, low-temperature thermal cracking resistance, water sensitivity test, incremental creep test and loaded wheel track test; and (iv) comparison of performance of selected paving mixes.

Download or read book Performance Evaluation of Asphalt Concrete Mixtures Containing Unmodified and Crumb Rubber Modified Asphalt Binders written by Gajanan Suresh Natu and published by . This book was released on 1998 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book THE LABORATORY PERFORMANCE AND AGING CHARACTERISTICS OF RUBBER MODIFIED ASPHALT MIXTURE USING A DRY PROCESS written by and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : The accumulation of waste tires generates severe environmental issues. Using crumb rubber processed from waste tires on the pavement could relieve the pressure of waste tire on the environment and improve the performance of the pavement as well. The application of crumb rubber on the pavement using the dry process was proved to be a cost-effective strategy in some projects, however, the interaction between the rubber and asphalt binder was unknown in the rubber modified asphalt mixture using the dry process, especially when reclaimed asphalt pavement was adopted. The performance improvement of the rubber particle to the asphalt mixture was closely related to the interaction. The influence of aging on the characteristics of rubber modified asphalt mixture using the dry process is critical to its long-term performance. The scope of the dissertation is to evaluate the performance of rubber modified asphalt mixture using a dry process when reclaimed asphalt pavement was adopted. The influence of aging on the characteristics of the rubber modified asphalt mixture and the extracted asphalt binder were investigated. This dissertation proposed the volumetric design of rubber modified asphalt mixture using the dry process. The aggregate gradation determination, rubber modified asphalt mixture preparation, design binder content determination, and moisture susceptibility evaluation were proposed. The quality control of the laboratory mixture design procedure was critical to guarantee the consistency of the asphalt mixture design in the laboratory and the results of mixture construction in the plant. The high temperature rutting performance and the low temperature cracking performance of plant mixed and laboratory compacted asphalt mixture was evaluated. The influence of various factors, which included mixture design parameters of the asphalt mixture (nominal maximum aggregate size, reclaimed asphalt pavement content, and asphalt content), rubber modification, mixture air void content, test temperature, and aging procedure, on the rutting and low temperature characteristics of asphalt mixtures were evaluated. Based on the evaluation of different assessment parameters, the rubber addition and the rubber addition and aging were the two most critical factors that influenced the rutting and low temperature cracking performance of different asphalt mixtures. The effect of the Trichloroethylene solvent in asphalt binder was investigated, and the extracted asphalt binder was assessed and compared with the base asphalt binder and rubber modified base asphalt binder. Both the existence of Trichloroethylene and the content of Trichloroethylene had a significant influence on the |G*| of unaged and PAV aged asphalt binder. The Trichloroethylene in the extracted asphalt binder significantly influenced the actual performance of the asphalt binder in the reclaimed asphalt binder, thus potentially compromising the success mixture design. The modified extraction procedure was proposed to improve the accuracy of the extraction procedure. The rubber particles in the asphalt mixture using the dry process were not totally interacted with asphalt binder, only the interacted rubber particles were extracted, and the influence of the interacted rubber particle was assessed. The aged asphalt binder weakened the low temperature performance of the extracted asphalt binder. The aged asphalt binder and rubber in extracted asphalt binder guaranteed the asphalt binder to sustain heavy traffic load, thus improved the permanent deformation resistance of asphalt binder.

Download or read book Evaluation of Hybrid Rubber Modified Asphalt Mixtures and Pavements A Case Study in Virginia written by Jhony Habbouche and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several state departments of transportation have recognized the benefits of modified asphalt mixtures in resisting multiple modes of climate- and load-induced distresses in flexible pavements. Throughout the past 50 years, asphalt binders have been modified with various components such as styrene-butadiene-styrene (SBS) polymers, ground tire rubber, chemicals (e.g., acid), recycled engine oils, etc., to achieve the desired properties. Hybrid rubber modified asphalt (HRMA) is an innovative engineered additive derived from ground tire rubber, elastomeric SBS polymers, and additive technologies. HRMA is specifically formulated to improve the high temperature stiffness and elastic properties of performance graded binders and the storage stability of modified binders. The purpose of this study was to document and assess HRMA field trials constructed in Virginia. This study documented and evaluated the constructability and laboratory performance of two plant-produced HRMA mixtures compared with the Virginia Department of Transportation (VDOT) typical SBS-modified surface mixtures as reference mixtures. No changes from routine established practices in terms of surface preparation, production at the plant, or paving operations were reported. The four mixtures were evaluated in terms of durability, dynamic modulus, resistance to rutting, and resistance to cracking using multi-level performance tests (basic, intermediate, advanced). All the derived observations indicated that HRMA modification could be as beneficial as regular SBS modification and could provide similar or better performance properties and characteristics for the resultant mixtures. The study recommends that VDOT consider the use of HRMA surface mixtures as an alternative to the current use of regular SBS-modified surface mixtures on higher-volume facilities. Since the sections evaluated in this study were placed in 2021, the 2-year performance data and corresponding observations are still considered preliminary. Continued monitoring of field performance will be needed to quantify any benefit of HRMA mixtures in comparison with regular SBS-modified surface mixtures. The study also recommends additional field trials with HRMA mixtures for further performance evaluation.

Download or read book Reacted and Activated Rubber RAR Modified Dense Graded Asphalt Mixtures Design and Performance Evaluation written by Sampat Kedarisetty and published by . This book was released on 2018 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The modification of asphalt mixtures with rubber in the conventional process includes specialized equipment for mixing and storage and concurrently necessitates reheating prior to use. Reacted and Activated Rubber (RAR) is a novel rubber-based asphalt mixture modifier that can be added into the mixture matrix without the complexities associated with wet mixing. The objective of this study was to design and assess the performance of RAR-modified dense-graded asphalt mixtures against key pavement distresses. Furthermore, the performance of RAR-modified mixtures was compared to the unmodified and commercially available rubber-modified asphalt-based mixtures. Two levels of RAR dosage at 2 and 4 % by total weight of mix were included with two different base binders. Four performance characteristics were analyzed: resistance to rutting at high temperatures, failure by fatigue, fracture energy, and susceptibility to moisture damage. Increased rut resistance and higher fatigue lives were observed for higher RAR contents. Statistical analyses revealed insignificant changes in fracture energy among the different mixtures, and all the mixtures were found to be resistant to moisture damage. RAR was concluded as a compatible promising rubber modifier with a significant potential to improve resistance of asphalt pavements against distresses and capable of providing extended life cycles. Because RAR showed significant improvement in the performance of the dense-graded asphalt mixtures, this study recommended expanding the scope of utilizing the RAR materials with other aggregate gradations both at the laboratory and field levels in future.

Download or read book Evaluation of Warm Mix Additives for Use in Modified Asphalt Mixtures written by Rukesh Maharjan and published by . This book was released on 2015 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research effort was to evaluate the use of warm-mix additives with modified (polymer-modified and terminal blend tire rubber) asphalt mixtures from Nevada and California. This research was completed in two stages: Sasobit and Advera were evaluated in first stage while Evotherm and Foaming were evaluated in second stage. The three main components of the experimental plan include: evaluation of mixture resistivity to moisture damage, pavement performance characteristics of the mixtures, and mechanistic analysis of the mixtures for simulated flexible pavement. The moisture resistivity of all mixtures were checked by Indirect Tensile Strength (ITS), and Dynamic Modulus (E*) tests. Dynamic Modulus Ratio (ECR) and Tensile Strength Ratio (TSR) were computed at multiple Freeze-Thaw (F-T) cycles for further evaluation of moisture sensitivity of mixtures. Flow Number (FN) and Flexural beam fatigue tests were conducted to evaluate the performance characteristics of WMA additives/technology. The terminal blend tire rubber-modified binder with lime treatment works effectively in resisting moisture damage, rutting, and to significantly-reasonably improve the fatigue life of the WMA Evotherm, Foaming, Advera and Sasobit mixtures. Hence, it is the best solution for the design and construction of sustainable asphalt pavements. The use of terminal blend rubberized asphalt binder is an excellent and economical selection in reducing tire waste and environmental impacts.

Download or read book Evaluation of Warm Mix Additives for Use in Modified Asphalt Mixtures written by Corina Borroel Wong and published by . This book was released on 2011 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The intention of this research effort is to evaluate the use of warm mix additives with typical polymer-modified and terminal blend tire rubber asphalt mixtures from Nevada and California. The research effort is broken into three phases that are intended to evaluate the impacts of warm mix additives with typical polymer-modified and terminal blend tire rubber asphalt mixtures from Nevada and California: moisture damage, performance characteristics, and mechanistic analysis. In Phase I of this research effort, mixture resistance to moisture damage was evaluated using the indirect tensile test and the dynamic modulus at multiple freeze-thaw cycles. Laboratory testing was conducted to address the following: (1) the impact of warm mix additive and reduced production temperatures on the moisture damage resistance of asphalt mixtures, (2) the impact of residual aggregate moisture on the moisture damage resistance of WMA mixtures, (3) the impact of warm mix additives on the moisture damage resistance of anti-strip treated WMA mixtures, and (3) the impact of long-term aging on strength gain and the moisture damage resistance of WMA mixtures. A total of one aggregate source, four warm mix asphalt technologies (Advera, Sasobit, Revix and Foaming) and three asphalt binder types (neat, polymer-modified and terminal blend tire rubber modified asphalt binders) typically used in both Nevada and California are being evaluated in this study. This thesis will only summarize the test results and findings of the Phase I of the study for two warm-mix additives: Advera and Sasobit. The evaluation of the other two technologies (i.e. Revix and Foaming) as well as the Phase II testing are still in progress and have not been completed.

Download or read book Mixture Design and Performance Prediction of Rubber modified Asphalt in Ohio written by Robert Y. Liang and published by . This book was released on 1998 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mixture design and performance characteristics of crumb rubber modified asphalt concretes were investigated in this research project to meet the requirements of the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991, which has required each State to incorporate scrap tire rubber into its asphalt paving materials. Specifically, the objectives of this research encompass the following: (i) investigation of the rheological properties of asphalt-rubber binder to determine optimum content of crumb rubber; (ii) development of optimum mix design for various applications, including both wet and dry mix processes; (iii) characterization of mechanical properties of recommended paving mixtures, including resilient modulus, fatigue cracking behavior, low-temperature thermal cracking resistance, water sensitivity test, incremental creep test and loaded wheel track test; and (iv) comparison of performance of selected paving mixes.

Download or read book Rubber Modified Asphalt Mix written by Charles S. Hughes and published by . This book was released on 1985 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the design and field installation of an asphalt mix containing up to 3.0% closed cell rubber by weight of the mix. The performance is discussed as well as possible reasons for the early failure of the mix. Suggestions are made for avoiding failures if it is decided to use rubber modified mixes in the future.

Download or read book Evaluation and Performance Based Mix Design of Rubber Modified Mixtures written by Dimitirios G. Goulias and published by . This book was released on 1997 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance and Sustainability based Analysis of Different Crumb Rubber Modified Asphalt Mixtures written by Berkay Tascioglu and published by . This book was released on 2013 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance of Ground Tire Rubber Modified Asphalt Mixture Overlays Over Jointed Concrete Pavements on US 60 in the Virginia Department of Transportation s Richmond District written by Harikrishnan Nair and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ground tire rubber (GTR) from scrap tires is used in asphalt mixtures (rubber modified asphalt [RMA]) for improving the performance of pavements. There are different ways to add GTR in asphalt mixtures, but the two primary methods are referred to as the “wet” and “dry” processes. The dry process incorporates GTR directly into the asphalt mixture during production (directly to the aggregates through the reclaimed asphalt pavement collar). The Virginia Department of Transportation (VDOT) has limited experience with RMA mixtures in Superpave dense-graded mixtures using the dry process, but the relative ease of mixture production makes the dry process an attractive option for RMA. In the fall of 2019, VDOT placed a dense-graded RMA mixture, SM 12.5 (GTR), on US 60 in VDOT’s Richmond District (New Kent County). This was the first use of a SM 12.5 (GTR) mixture in Virginia using the dry process method. The purpose of this study was to establish a performance baseline for a GTR modified dense-graded asphalt mixture that was designed and produced using the dry process. The US 60 project also included the use of a thin hot mix asphalt concrete overlay (THMACO) as an interlayer. An assessment of the THMACO as an interlayer was a secondary objective of the study. The study found that dry process SM 12.5 (GTR) mixture can be produced and placed with no significant field-related concerns and that the special provision developed for its use was effective. Density requirements were achieved, and the as-placed mat had excellent (very low) permeability characteristics. Laboratory performance testing showed the SM 12.5 (GTR) mixture to be more crack resistant than conventionally modified polymer (SM 12.5E) mixtures. Conventionally modified SM E mixtures had slightly better rutting performance. However, this conclusion was based on performance testing and thresholds that were developed for non-modified asphalt mixtures. Additional laboratory and field performance comparison is needed to develop mixture acceptance criteria for GTR mixtures. Further, THMACO mixtures had excellent laboratory reflective cracking resistance properties. They performed particularly well in the Texas overlay test. Grading of extracted (from the asphalt mixture) binder may not provide an accurate representation of the binder performance for the dry process GTR modified asphalt. Continued monitoring of performance will be needed to quantify any benefit of SM 12.5 (GFR) mixtures in comparison with regular SM E mixtures. The study recommends additional field trials with SM 12.5 (GTR) mixtures for performance evaluation. Further, the study recommends continued use of a THMACO as an interlayer to mitigate reflective cracking for composite pavements.

Download or read book Performance Survey on Open graded Friction Course Mixes written by Gerald Huber and published by Transportation Research Board. This book was released on 2000 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: This synthesis will be of interest to pavement construction, maintenance, design, and materials engineers; pavement contractors; and others interested in the use of open-graded friction course (OGFC) mixes. It describes the current state of the practice on the use of OGFC mixes, including information regarding design, materials, construction, maintenance, and rehabilitation strategies. Alternative treatments to traditional OGFC are also identified and discussed. Information was collected by surveying U.S. and Canadian transportation agencies and by conducting a literature search to gather additional insight into North American and European practices. This TRB report describes the recent performance of North American OGFC mixes and European porous asphalt by identifying benefits and stress indicators. A new generation of OGFC mixes has evolved over the last 5 years with changes that have been reported to dramatically improve performance. This synthesis describes new materials and design methods being used, as well as the applicability of the new generation of open-graded mixtures to North American use.

Download or read book Evaluation of Warm Mix Asphalt Additives for Use in Modified Asphalt Mixtures written by Zahi Chamoun and published by . This book was released on 2013 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: