Recommended Use of Reclaimed Asphalt Pavement in the Superpave Mix Design Method PDF Download

Author: Rebecca McDaniel
Publisher:
ISBN:
Category : Pavements, Asphalt
Languages : en
Pages : 24

View

Book Description

Author: Amy Epps Martin
Publisher:
ISBN: 9780309481045
Category : Asphalt
Languages : en
Pages : 284

View

Book Description
"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."--

Author: Imad L. Al-Qadi
Publisher:
ISBN:
Category : Pavements, Asphalt
Languages : en
Pages : 32

View

Book Description
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.

Author: Michael Berry
Publisher:
ISBN:
Category : Aggregates (Building materials)
Languages : en
Pages : 172

View

Book Description
This research effort was focused on evaluating the feasibility of using minimally processed reclaimed asphalt pavement (RAP) as aggregate replacement in concrete pavements. This 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. A statistical experimental design procedure (response surface methodology - RSM) was used to investigate proportioning RAP concrete mixtures to achieve desired performance criteria. Based on the results of the RSM investigation, two concrete mixtures were selected for further evaluation: a high RAP mix with fine and coarse aggregate replacement rates of 50 and 100 percent respectively, and a "high" strength mix with one half of the RAP used in the high RAP mix. Both mixes met MDT concrete pavement specifications for slump (1.5 inches), air content (6 percent), and 28-day compressive and tensile strengths (3,000 psi and 500 psi, respectively). These two concrete mixtures were subjected to a suite of mechanical and durability tests to evaluate their potential use in Montana roadways. Mechanical properties tested were compressive and tensile strength, elastic modulus, shrinkage, and creep. Durability tests included alkali-silica reactivity, absorption, abrasion, chloride permeability, freeze-thaw resistance, and scaling. Overall, both mixes performed adequately in these mechanical and durability tests, although it is important to note that the inclusion of RAP had an obvious negative impact on nearly every property tested relative to those of control mixes made with 100 percent conventional aggregates.

Author:
Publisher:
ISBN:
Category : Pavements, Asphalt
Languages : en
Pages : 46

View

Book Description
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.

Author: Jon A. Epps
Publisher: Transportation Research Board National Research
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 114

View

Book Description
This synthesis will be of interest to pavement designers, construction engineers, and others interested in economical methods for reconstructing or rehabilitating bituminous pavements. Information is provided on the processes and procedures used by a number of states to recycle asphalt pavements in place without application of heat. Since 1975 a growing number of state highway agencies have reconstructed or rehabilitated asphalt pavements by recycling the old pavement in place. This report of the Transportation Research Board describes the processes used for cold in-place recycling, including construction procedures, mix designs, mixture properties, performance, and specifications.

Author: Randy Clark West
Publisher:
ISBN: 9780309259132
Category : Pavements, Asphalt
Languages : en
Pages : 164

View

Book Description
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.

Author: Frank Meyer
Publisher:
ISBN:
Category : Asphalt
Languages : en
Pages : 122

View

Book Description
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.

Author: Mansour Solaimanian
Publisher:
ISBN:
Category : Pavements, Asphalt
Languages : en
Pages : 140

View

Book Description

Author:
Publisher:
ISBN:
Category : Pavements, Asphalt
Languages : en
Pages :

View

Book Description
This report presents the findings from the first year of a three year Austroads study which aims to maximise the re-use of reclaimed asphalt pavement (RAP) in new asphalt product. The objective of this first year of study is to improve the methodology for the characterisation of RAP binders and the design of the binder blend in asphalt mixes containing RAP. The study included a literature survey of the current international state of practice in terms of RAP binder characterisation. It further included experiments to develop a more practical and cost-effective approach to characterising the properties of binder blends containing RAP. The experimental work showed that the Dynamic Shear Rheometer (DSR) can be used to obtain viscosity parameters similar to the Shell sliding plate viscosity at 45 C and the capillary viscosity at 60 C. The DSR results are also more repeatable than the results of the Shell sliding plate test, which has conventionally been a more common test used in Australia for the characterisation of RAP binder. The results show that for the RAP sources under study, a blend of C170 with 10% to 20% RAP does result in a viscosity equivalent to that of a C320, as generally accepted in current practice. The DSR based methodology used in this study provides a practical, consistent and cost-effective method to characterise RAP binder blends. As successfully demonstrated in this study, the viscosity results from the DSR tests can be used to design RAP binder blends to a desired viscosity. The methodology will be further validated during the next year of this study, when it will be used to design binder blends for asphalt mixes containing various percentages of RAP.