Literature Review: Performance of RAP/RAS Mixes and New Direction
Fujie Zhou, Cindy Estakhri, and Tom Scullion, April, 2014
In the last several years reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) have been widely used in asphalt mixes in Texas. The use of RAP/RAS can significantly reduce the initial cost of asphalt mixtures, conserve energy, and protect our environment. There are always two main concerns: variability of RAP/RAS and durability (or cracking) of RAP/RAS mixes. Past studies in Texas have clearly indicated that both RAP and RAS have acceptable variability following the best practices for handling RAP/RAS. This study will focus on the durability of RAP/RAS mixes. This report presents a review of using RAP/RAS in asphalt mixes, the identified research focus, and the revised field experimental test plan.
Specifically, this report discusses the field performance of RAP/RAS mixes in Texas and other states, and the observed field performance data strongly support the necessity of establishing a RAP/RAS mix design system for project-specific service conditions. The best practices for using RAP/RAS in hot-mix asphalt (HMA) and warm mix asphalt (WMA) mixtures, including RAP/RAS processing, mix design, production, and field construction, are also documented. Additionally, the new specification for asphalt mixes in Texas is reviewed and then a revised field experimental test plan for validating the new specification is recommended.
Keywords: Reclaimed Asphalt Pavement, Recycled Asphalt Shingles, Asphalt Mix Design, Field Performance
ENTIRE REPORT (Adobe Acrobat File – 6.2 MB)