Download or read book Feasibility of Using Recycled Asphalt Pavements RAP in Hot Mix Asphalt for the City of Phoenix Arizona written by Gonzalo Zelada Arredondo and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Asphalt concrete is the most recycled material in the United States and its reclamation allows the positive reuse of the constituent aggregates and asphalt binder, contributing to the long-term sustainability of the transportation infrastructure; decreasing costs, and the total energy and greenhouse emissions embodied into new materials and infrastructure. Although the national trends in Reclaimed Asphalt Pavements (RAP) usage are encouraging, the environmental conditions in Phoenix, Arizona are extreme and needs further consideration. The objective of this research study was to evaluate the viability of using RAP in future pavement maintenance and rehabilitation projects for the City. Agencies in the State of Arizona have been slow adopting the use of RAP as a regular practice. While the potential benefits are great, there is some concern on the impact to long-term pavement performance. RAP millings were sampled from the city's stockpiles; processed RAP and virgin materials were provided by a local plant. Two asphalt binders were used: PG 70-10 and PG 64-16. RAP variability was evaluated by aggregate gradations; extracted and recovered binder was tested for properties and grading. A mixture design procedure based on the City's specifications was defined to establish trial blends. RAP incorporation was based on national and local practices. Four different RAP contents were studied 10%, 15%, 25%, and 25% content with a softer binder, in addition to a control mix (0% RAP). Performance tests included: dynamic modulus to evaluate stiffness; Flow Number, to assess susceptibility for permanent deformation (rutting); and Tensile Strength Ratio as a measure of susceptibility to moisture damage. Binder testing showed very stiff recovered asphalts and variable contents with a reasonable variability on aggregate gradations. Performance test results showed slightly higher modulus as RAP content increases, showing a slight improvement related to rutting as well. For moisture damage potential, all mixtures performed well showing improvement for RAP mixtures in most cases. Statistical analysis showed that 0%, 10%, 15% and 25% with softer binder do not present significant statistical difference among mixtures, indicating that moderate RAP contents are feasible to use within the City paving operations and will not affect greatly nor negatively the pavement performance.

Download or read book Feasibility of Using 100 Recycled Asphalt Pavement Mixtures for Road Construction written by Russell Edgar Carlson IV and published by . This book was released on 2014 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recycled Asphalt Pavement (RAP) is the largest recycled good in the United States and 80 million tons are recycled yearly, saving taxpayers about $1.5 billion dollars. This paper explores the possibility of utilizing 100% RAP materials in asphalt pavement. Asphalt mixtures are produced at 135°C in a typical asphalt plant. However, at 135°C, not all binder from RAP materials may not become effective for coating aggregates. The main objective of the study is to determine the amount of effective binder available from RAP in the asphalt plant. The 100% RAP mixes have aged binder that can alter mix designs and interaction with virgin binder. In this study, to determine low temperature cracking resistance and fatigue performance, samples were prepared using a 100% RAP mix with no virgin binder and a 100% RAP mix with virgin asphalt binder to achieve the optimum binder content of the mix. Second, to determine the effectiveness of binder from RAP materials, compaction tests were performed by heating RAP materials at various temperatures. It was found that 100% RAP mixes cannot be feasible for field use if additional virgin binder is added to reach the optimum asphalt content. Based on limited test results, the low temperature grade was not within proper limits but the beam fatigue testing results were acceptable. Based on compaction test results, additional heating is needed to increase the effectiveness of asphalt binder from RAP materials.

Download or read book 100 Recycled Hot Mix Asphalt and the Use of Rejuvenators written by Martins Zaumanis and published by . This book was released on 2014 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The desire to find more sustainable paving practices as well as the dramatically rising binder costs driven by the growing global demand for paved roads, has led to increased interest of the use of reclaimed asphalt pavement (RAP) in very high amounts. So far the major industry trend has been to develop procedures, invest in technologies and build confidence in mixtures with up to 40 % RAP content. However, a few innovators have refined 100 % recycling technologies over the past four decades to a level where routine production of 100 % recycled hot mix asphalt is in clear sight. Rejuvenators are an integral part of 100 % recycled asphalt production and they can also allow to significantly increase the RAP content for conventionally produced asphalt mixtures. An evaluation of the feasibility of production of 100 % recycled hot-mix asphalt was made and the use of rejuvenators is presented in this study. 100 % recycling is discussed by evaluating ten readily available production technologies along with proposing mix design procedures and identifying best RAP management strategies. A total of eleven different products were evaluated for restoring the RAP binder grade with a definite conclusion that achieving target grade (PG or empirical specification) is possible. In addition a rheological, micromechanical and chemical characterization was performed with select rejuvenators and binders from Strategic Highway Research Program (SHRP) library. To further assess the rejuvenators and feasibility of 100 % RAP recycling a series of 100 % mixture tests were performed that indicated significant improvement in low temperature and fatigue cracking resistance while providing a rut resistant mixture. With the use of some rejuvenators a performance equal to that of reference virgin mix was achieved. Based on these findings of rejuvenator effectiveness a methodology for choice of rejuvenator type and dose was proposed. Finally, a cradle-to-gate analysis of environmental effects was performed which indicated 35 % CO2eq savings per ton of produced 100 % RAP asphalt mixture compared to virgin mix while cost analysis showed at least 50 % savings in material related expenses. A short video summarizing the research is available at http://youtu.be/y-rYvdGiEbY.

Download or read book Evaluation of Field produced Hot Mix Asphalt HMA Mixtures with Fractionated Recycled Asphalt Pavement RAP written by William Robert Vavrik and published by . This book was released on 2008 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Leaching Characteristics of Recycled Asphalt Pavement written by Kenneth A. Winter and published by . This book was released on 2006 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recycled asphalt pavements (aka milled asphalt) may be safe to use as fill. Milled asphalt (frequently referred to as recycled asphalt pavement ... (RAP) is commonly mixed with hot mix asphalt and re-used in paving projects. However, some research has been conducted on the feasibility and potential environmental impact of using milled asphalt as fill material for bridge approaches and similar applications. Even when used in applications above mean high water (an unsaturated condition), concern has been expressed that lechate resulting from flood or rainfall could be contaminated by such recycled asphalt and thus have negative environmental consequences. Results of numerous field studies and standardized tests, including the Toxicity Characteristic Leachate Procedure (TCLP) test, suggest that typical RAP can be used as "clean fill" without undue negative environmental consequences.

Download or read book Feasibility of Reclaimed Asphalt Pavement as Aggregate in Portland Cement Concrete Pavements written by and published by . This book was released on 2015 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research was focused on evaluating the feasibility of using minimally processed reclaimed asphalt pavement (RAP) as aggregate replacement in concrete pavements. An initial phase of research demonstrated that concretes with up to 50 percent of the fine aggregates and 100 percent of the coarse aggregates replaced with RAP were suitable for concrete pavement. However, the field performance of these mixes was not evaluated. Further, these initial mixes contained a significant proportion of cement in order to achieve the desired performance criteria, hindering the economic benefit of using this recycled material in concrete. Therefore, the research discussed herein focused on: (1) evaluating the field performance of RAP concrete through a field demonstration project, and (2) reducing the amount of cement required in the RAP concrete by including water-reducing admixtures. As part of the field demonstration project, two RAP-concrete slabs were cast on a roadway near Lewistown, MT, and monitored for damage, shrinkage, and curling over a two-year period. There were no logistical issues associated with the construction of the slabs, and no damage and only minor shrinkage/curling was observed. In regards to the mixture optimization, two modified mix designs with reduced cement contents were developed, and evaluated with a suite of mechanical and durability tests. Mechanical properties tested were compressive and tensile strength, elastic modulus, and shrinkage. Durability tests included abrasion, chloride permeability, freeze-thaw resistance, and scaling. These mixes performed well with respect to all tests, with the exception of the chloride permeability. Although both mixes performed well, the resulting mixes were lean and were difficult to get good consolidation. Moreover, the process for batching these mixes may be considered a hindrance, as it involved slump adjusting the mixes with the water-reducing admixture. This was required because the nature of the RAP aggregates made it difficult to adjust mixes for variations in moisture content.

Download or read book Feasibility of Reclaimed Asphalt Pavement as Aggregate in Portland Cement Concrete Pavement written by Bethany Noel Bermel and published by . This book was released on 2011 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Each year, the US highway industry produces over 100 million tons of reclaimed asphalt pavement (RAP) through the rehabilitation and construction of the nation's roads. Using RAP as aggregate in Portland cement concrete pavement (PCCP) is one attractive application for a further use of this recyclable material. Earlier research has demonstrated the feasibility of creating concrete with RAP aggregate; however, prior studies focus on mechanical properties of the material. This research project will further distinguish the properties of this material and draw conclusions on the concrete's aptness for use as a pavement in Montana. This thesis encompasses the development of candidate RAP in PCCP mixtures that will subsequently move forward for a more thorough evaluation of their material properties. The mixing experiment and preliminary testing phases of this project provided information to draw a number of conclusions about the appropriateness of RAP aggregate in PCCP, including: (1) using conventional practices, PCCP containing RAP aggregate (20 percent fine and 45 percent coarse) can achieve compressive strengths in excess of 3,000-psi; (2) as the RAP replacement rate is increased, the compressive strength of the concrete decreases; (3) fine RAP aggregate appears to have a more detrimental effect on the concrete than coarse aggregate; (4) concretes with a relatively high RAP replacement rate (50 percent fine and 100 percent coarse) may be suitable for transportation applications; (5) at high RAP replacement rates, there appears to be a benefit (relative to concrete strength) in using increased replacements of both fine and coarse RAP, rather than singly replacing just one aggregate gradation; and (6) concrete containing RAP displays increased flexural strengths as compared to traditional PCCP. This material research was performed using a Design of Experiments (DOE) method. The suitability of this statistical method as a mix design development tool was characterized through several important findings, which include: (1) the DOE method was effective in distinguishing mixture behaviors; (2) mix design optimization is readily accomplished using the statistical model generated from the DOE data; and (3) variability in the concrete mixing and testing processes has a significant effect on the capabilities of the statistical model.

Download or read book Impact of High RAP Content on Structural and Performance Properties of Asphalt Mixtures written by Imad L. Al-Qadi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Concrete Containing Recycled Asphalt Pavement for Use in Concrete Pavement written by Nabil Hossiney and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Our study evaluated the feasibility of using concrete containing recycled asphalt pavement (RAP) in concrete pavement applications. Concrete containing 0[percent], 10 [percent], 20[percent] and 40[percent] of RAP were produced in the laboratory, and evaluated for their properties which are relevant to performance of concrete pavements. Using the measured properties of these concretes containing RAP, finite element analysis was then performed to determine how the concretes containing different amounts of RAP would perform if it were used in a typical concrete pavement in Florida. Results of the laboratory testing program indicate that compressive strength, splitting tensile strength, flexural strength and elastic modulus of the concrete decrease as the percentage of RAP increases. The coefficient of thermal expansion appears to increase slightly with the use of one RAP, and decrease slightly with the use of a second RAP. The drying shrinkage appears to increase slightly with increasing RAP content. When analysis was performed to determine the maximum stresses in a typical concrete pavement in Florida under critical temperature and load conditions, the maximum stress in the pavement was found to decrease as the RAP content of the mix increases, due to a decrease in its elastic modulus. This indicates that using a concrete containing RAP can result in improvement in the performance of concrete pavements.

Download or read book Feasibility of Reclaimed Asphalt Pavement RAP Use As Road Base and Subbase Material written by Edward J. Hoppe and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study was to investigate the current state of the practice with regard to the use of reclaimed asphalt pavement (RAP) material for road base and subbase applications and the potential for such use by the Virginia Department of Transportation (VDOT). To achieve the objectives of the study, a comprehensive review of the literature was conducted and the current state of the practice by other state departments of transportation was analyzed. The results indicated that the use of RAP in road base and subbase materials is viable and has been implemented by a number of transportation agencies. There seemed to be no major environmental concerns associated with using unbound RAP without chemical stabilization agents. Numerous sources of RAP are available in Virginia. Based on practices adopted by other state transportation agencies, the study recommends that VDOT allow the use of RAP in a road base material on highway construction projects. The study further recommends that the allowable percentage of RAP in a blend be phased in gradually to allow VDOT to gain familiarity with the materials and processes involved. Compaction testing could be performed with current methods while alternative procedures were analyzed for suitability. Once a standard specification has been developed, sites for long-term field studies will be identified to implement further the recommendations stemming from this study. There is a potential for significant economic benefits if RAP is used in base and subbase applications. Approximately 30% in material cost savings could be realized with a 50/50 blend of RAP and virgin aggregate. In addition, this application would likely result in a substantial reduction in the amount of RAP material currently stockpiled in Virginia.

Download or read book Rejuvenation of Reclaimed Asphalt Pavement RAP in Hot Mix Asphalt Recycling with High RAP Content written by Karen A. O'Sullivan and published by . This book was released on 2011 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This study aims to understand intermingling process between rejuvenators and aged asphalt binders in reclaimed asphalt pavement (RAP) materials during RAP recycling operations in pavement construction. This study presents results of a laboratory study on the use of rejuvenators to recycle age hardened asphalt binders in RAP. Laboratory Hot Mix Asphalt (HMA) samples were prepared with RAP millings from one specific pavement and a commercial rejuvenator, with 80 to 90 percent RAP content. The following mixes with various amount of the rejuvenator were evaluated: a control mix prepared from burned RAP aggregate and virgin asphalt binder, another control mix prepared with heated RAP, a recycled RAP mix with 1% rejuvenator (at the weight of the total mix), a recycled RAP mix with 0.5% rejuvenator, and a recycled RAP mix with 0.5% rejuvenator and 0.5% virgin asphalt binder. Dynamic modulus test results of laboratory prepared samples were obtained for a range of temperatures over an eleven-week period of accelerated aging at 60o.C in an inert gas oven and a conventional convection oven. Accelerated aging protocol was used to evaluate the intermingling process associated with diffusion mechanism between the rejuvenator and aged asphalt binder while an argon inert gas oven provides an environment where oxidation-related ageing and hardening in rejuvenated asphalt binders can be eliminated. The dynamic modulus data of six distinct mixes were statistically analyzed and compared to the results reported in the literature for virgin and low percentage recycled mixes. Collected data suggest that the use of rejuvenator is a viable option for recycling HMA with high RAP material content.

Download or read book Study of Hot Mix Recycling of Asphalt Pavements written by Frank Meyer and published by . This book was released on 1983 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in hot mix recycling has recently been stimulated by:rising cost of asphalt cement and fuels; depletion and risingcosts of readily available conventional aggregate resources; theneed to reduce energy consumption; reduction in available fundsfor transportation facilities due to inflation; and, environmental problems due to mining of aggregate materials. Since hot mix recycling can offer advantages in all these areas, the overall objective of this project is to encourage the use ofthis cost and energy efficient strategy in the rehabilitation andmaintenance of pavements in the national road system.

Download or read book Research and Application of Hot In Place Recycling Technology for Asphalt Pavement written by Banting W.P. Sze and published by Woodhead Publishing. This book was released on 2020-11-12 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research and Application of Hot In-Place Recycling Technology for Asphalt Pavement is the first comprehensive book on the topic that presents over two decades of theoretical and practical experience gained in China. The book gives comprehensive coverage of HIPR, including pavement evaluation, distress analysis, mix design, processes and equipment selection, implementation and acceptance criteria. In eight chapters, this book covers HIPR from theoretical and practical viewpoints, and provides detailed case-studies based on real-world experience. This book includes everything engineers need to apply HIPR to improve sustainability and reduce disruption during the maintenance and repair of asphalt. - Presents, for the first time in English, decades of experience and research on Hot in-Place Recycling Technology (HIPR) for asphalt pavements - Considers all aspects of HIPR, giving engineers all they need to use the technique for road maintenance and repair - Details how HIPR drastically improves the sustainability of asphalt and reduces disruption to traffic during repair and maintenance work - Includes detailed case studies from thirty years of HIPR in China, giving context and practical know-how

Download or read book Reclaimed Asphalt Pavement written by Imad L. Al-Qadi and published by . This book was released on 2007 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Illinois has been recycling Reclaimed Asphalt Pavement (RAP) material into hot-mix asphalt (HMA) since 1980, this research project seeks to determine the appropriate level of contribution that should be given to the residual asphalt binder in RAP.

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 Evaluating the Effects of Recycling Agents on Asphalt Mixtures with High RAS and RAP Binder Ratios written by Amy Epps Martin and published by . This book was released on 2020 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: "More than 90 percent of highways and roads in the United States are built using hot-mix asphalt (HMA) or warm-mix asphalt (WMA) mixtures, and these mixtures now recycle more than 99 percent of some 76.2 million tons of reclaimed asphalt pavement (RAP) and about 1 million tons of recycled asphalt shingles (RAS) each year. Cost savings in 2017 totaled approximately $2.2 billion with these recycled materials replacing virgin materials. The TRB National Cooperative Highway Research Program's NCHRP Research Report 927: Evaluating the Effects of Recycling Agents on Asphalt Mixtures with High RAS and RAP Binder Ratios presents an evaluation of how commercially available recycling agents affect the performance of asphalt mixtures incorporating RAP and RAS at high recycled binder ratios."--