Evaluation of WMA Technologies and Recycled Asphalt Pavement on Nevada Aggregates
Evaluation of WMA Technologies and Recycled Asphalt Pavement on Nevada Aggregates

Author: Kevin Morgan

Publisher:

Published: 2013

Total Pages: 79

ISBN-13:

DOWNLOAD EBOOK

Nevada Department of Transportation (NDOT) is currently experimenting with warm mix asphalt (WMA) technologies and recycled asphalt pavement (RAP). The purpose of this experiment is to evaluate the effects of various WMA technologies and various levels of RAP on Nevada mixtures using current Superpave WMA and RAP design techniques. This part of the project evaluated aggregates from Lone Mountain, Rinker, North Tenaya, and Sloan. Advera, Evotherm 3G, and Sonnewarmix, were the WMA technologies evaluated, while plant foaming mixtures will be evaluated at a later time. It was decided that two levels of RAP would be evaluated; one level found through the use of a traditional blending chart and one through a new method known as the mortar experiment. It was also decided that samples mixed at 0.2 percent below optimum binder content (OBC) would be compared to OBC samples. The mortar experiment determined levels of RAP binder replacement for Lone Mountain and Rinker aggregates much lower than the blending chart. The levels were 17 percent and 39 percent, respectively. A mix was successfully designed and tested with 15 percent RAP binder replacement with favorable results; a mix with 35 percent RAP binder replacement will be designed and tested in the near future. It is suggested that further research should be conducted on the mortar method to explore minimization of variables during the experiment. Samples at 0.2 percent binder below the OBC performed comparable to samples at OBC. It is suggested that further analysis of coating and compactability should be performed on the evaluated mixtures as per Superpave WMA standards. As expected, mixes with WMA performed well in resistance to moisture damage and reflective cracking, but did not perform as well in resistance to rutting tests. Mixtures with RAP behaved the opposite; good resistance to rutting but not as good resistance to moisture damage and reflective cracking.

Evaluation of Nevada's Warm Mix Asphalt Mixtures with Recycled Asphalt Pavements
Evaluation of Nevada's Warm Mix Asphalt Mixtures with Recycled Asphalt Pavements

Author: Balasekaram Jayaprakas

Publisher:

Published: 2016

Total Pages: 71

ISBN-13:

DOWNLOAD EBOOK

The purpose of this study is to evaluate warm mix asphalts (WMA) with recycled asphalt pavement (RAP) from Nevada. For this study, four different warm mix technologies and four different aggregate sources with two different percentages of recycled asphalt binder ratios were used. Aggregates from Lone Mountain, North Tenaya, Spanish Springs and Lockwood were used with appropriate binders for the particular climate conditions in those areas. All the aggregates were lime-marinated, as per requirement of the Nevada Department of Transportation. Advera, Evotherm 3G, Sonnewax and waterfoam were the warm mix technologies evaluated. All four WMA mixtures satisfied all the criteria for resistance to moisture damage with or without RAP for all the aggregate sources used. In terms of fatigue, the WMA mixtures showed better results than the HMA mixture. But for the rutting resistance all of the WMA mixtures showed lower values than the HMA mixtures. This was expected, even though the WMA's rutting resistance improved when RAP was added.

Field Performance of Asphalt Pavements with New Technologies in Northern Nevada
Field Performance of Asphalt Pavements with New Technologies in Northern Nevada

Author: Benjamin Michael Faeth

Publisher:

Published: 2014

Total Pages: 390

ISBN-13:

DOWNLOAD EBOOK

The Regional Transportation Commission (RTC) of the Washoe Valley Area has been tasked to determine if three advanced asphalt pavement technologies and one modified aggregate gradation are suitable for implementation within Reno, Stead, and Sparks Nevada. This was accomplished through research and test roads and Intersections to determine if Recycled Asphalt Pavement (RAP), Warm Mix Asphalt (WMA), Polymer-Modified Asphalt Binder, and the Type 2-R aggregate gradation were succeeding in their design plans. Over the course of several years the streets being used by RTC to test the technologies are succeeding within their design lifespans, and the Intersections being used to test the Type 2-R aggregate gradation are showing significant resistance to rutting. Due to the roads and Intersections not being more than 10 years old, these conclusions are subject to change over time.

Performance Evaluation of Warm Mix Asphalt Mixtures Incorporating Reclaimed Asphalt Pavement
Performance Evaluation of Warm Mix Asphalt Mixtures Incorporating Reclaimed Asphalt Pavement

Author: Brian Hill

Publisher:

Published: 2011

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

Sustainability is a cornerstone of today0́9s engineering world. Warm mix asphalt (WMA) and reclaimed asphalt pavement (RAP) are the most prominent sustainable materials in asphalt concrete pavements. WMA is a not a new concept, however new innovations and increased usage of WMA has been spurred by the increased focus on sustainable infrastructure systems. WMA enables reduced production temperatures through the use of wax, water, or other chemical packages. The effects of reduced production temperatures include fuel use and emissions reductions, improved compaction, and possible RAP concentration increases. RAP is the primary recycled product of the aged asphalt concrete pavements and its use leads to reductions in virgin aggregate and asphalt demand. However, significant performance issues can stem from the individual integration of WMA or RAP materials in asphalt concrete. In particular, WMA technologies can increase moisture and rutting susceptibility while RAP significantly increases the stiffness of the resulting mixture. Consequently, quality performance of sustainable asphalt pavements may require the combined use of WMA and RAP to produce mixtures with sufficient stiffness and moisture and fracture resistance. This study evaluates the potential of WMA technologies and their integration with RAP. Initially, an extensive literature review was completed to understand the advantages, disadvantages, and past field and lab performance of WMA and RAP mixtures. Rotational viscometer and bending beam rheometer tests were then used to evaluate Sasobit, Evotherm M1, and Advera WMA modified and unmodified binders. Finally, virgin and 45% RAP mixtures were designed and tested to examine the rutting, moisture, and fracture resistance of WMA and HMA mixtures. The results of this experiment provided several key observations. First, viscosity reductions may not be the primary cause for the availability of reduced production temperatures for WMA technologies. Second, WMA additive properties have a significant effect upon fracture, moisture, and rutting resistance. Furthermore, the addition of RAP to WMA mixtures improved the rutting and moisture sensitivity performance as characterized in the Hamburg and Tensile Strength Ratio testing procedures.

Evaluation of the Moisture Susceptibility of WMA Technologies
Evaluation of the Moisture Susceptibility of WMA Technologies

Author: Amy Epps Martin

Publisher: Transportation Research Board

Published: 2014

Total Pages: 109

ISBN-13: 030928368X

DOWNLOAD EBOOK

"TRB's National Cooperative Highway Research Program (NCHRP) Report 763: Evaluation of the Moisture Susceptibility of WMA Technologies presents proposed guidelines for identifying potential moisture susceptibility in warm mix asphalt (WMA). The report also suggests potential revisions to the Appendix to AASHTO R 35, "Special Mixture Design Considerations and Methods for WMA" as a means to implement the guidelines."--publisher's description

Laboratory Evaluation of Characteristics of Recycled Asphalt Pavement in Kansas
Laboratory Evaluation of Characteristics of Recycled Asphalt Pavement in Kansas

Author:

Publisher:

Published: 2011

Total Pages: 126

ISBN-13:

DOWNLOAD EBOOK

The main objective of this research was to evaluate characteristics of milled Recycled Asphalt Pavements (RAP) collected from selected milled roadways in Kansas. The RAP was collected from three selected milled roadways including K-25 in Grant County, K-25 in Logan County, and US-83 in Scott County. The aggregates were extracted from RAP, and tested for characteristics including gradation, specific gravity, Fine Aggregate Angularity (FAA), Coarse Aggregate Angularity (CAA), flat and elongation (F & E), and Los Angeles Abrasion (LA) values. Binder from each source was extracted from the RAP, and recovered for a PG grade testing. The changes in the properties of aggregates after milling from the roadways as compared with the original aggregates are discussed. The variability of RAP aggregates was analyzed. In addition, the differences between the properties of aggregates extracted by centrifuge and ignition methods are compared.

Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content
Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content

Author: Randy Clark West

Publisher: Transportation Research Board

Published: 2013

Total Pages: 162

ISBN-13: 0309259134

DOWNLOAD EBOOK

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.

Laboratory Evaluation of Warm Mix Asphalt Influence on Theoretical Maximum Specific Gravity
Laboratory Evaluation of Warm Mix Asphalt Influence on Theoretical Maximum Specific Gravity

Author: Jianhua Yu

Publisher:

Published: 2012

Total Pages: 8

ISBN-13:

DOWNLOAD EBOOK

Warm mix asphalt (WMA) technology provides sufficient workability for asphalt mixtures at reduced mixing and compaction temperatures. Depending on the WMA technology, the typical temperature reduction range is 20 °C to 55 °C below hot mix asphalt (HMA) production temperatures. WMA involves chemical and wax additives that are added to an asphalt binder or incorporated through the use of foaming technology. The main advantages of WMA are reduced emissions and a reduction in combustible fuel consumption. Ongoing WMA research projects have documented some differences between HMA and WMA mixes, prompting numerous research projects that are investigating these concerns. The purpose of this research is to evaluate the volumetric properties by directly comparing laboratory produced WMA and HMA mixes. This study investigates the impact of WMA additives on the volumetric properties, specifically, the theoretical maximum specific gravity (Gmm). The Gmm testing followed the procedure of ASTM D2041. Two mix designs with HMA binder were produced, one without recycled asphalt pavement (RAP) and the other with 30 % RAP. After the mix designs were completed, no additional changes were made to account for the addition of the WMA technology. The mixes included the WMA technologies Sasobit and Advera, as well as an HMA control, for a total of six different laboratory produced mixes. Each mix was produced at 120 °C, 135 °C, and 150 °C, and each mix was oven cured for 1, 2, and 4 h. The test results were analyzed using statistical principles to determine whether differences in the Gmm values were statistically significant. The results show that temperature has little impact on Gmm. Gmm was not affected by curing times of 1 and 2 h, but the longer curing time of 4 h resulted in a statistically significant increase in Gmm. Further analysis revealed that the mix sensitivity to curing time depends on the amount of RAP in the mix. For the mix designs studied, the Advera Gmm values were similar to the HMA values, but the Sasobit Gmm values were statistically lower than the Advera values.