Properties of Asphalt Mixtures with RAP in the Mechanistic-Empirical Pavement Design of Flexible Pavements: A Preliminary Investigation

Abstract

The Reclaimed Asphalt Pavement (RAP) can save money and save energy when recycling is done on the side. The use of RAP significantly reduced the usage of natural resources (i.e., aggregate and petroleum product), and assisted local governments to meet the global reducing disposal standard. In this study, a 15% RAP was used in Superpave mixtures and a mixture without RAP was used as the control mixture. Comprehensive laboratory tests such as dynamic modulus and rutting tests were conducted to evaluate the performance of the mixtures with RAP. The results show that the difference in E* for control and RAP mixture compacted at 7% air void is not significant. However, it was found that the additional 15% RAP decreased the rut depth significantly after 8000 cycles using the Asphalt Pavement Analyzer (APA). The dynamic modules of asphalt mixtures were used in the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) analysis for a given pavement structure as well. In the preliminary study, it was found that an additional 15% of RAP reduced the rut depth up to 13% over a 20-year period in MEPDG analysis.