Effect of Recycled Asphalt Pavement on Thermal Cracking Resistance of Hot-Mix Asphalt

Abstract

This study explored the thermal cracking resistance of hot-mix asphalt (HMA) mixes containing recycled asphalt pavement (RAP). One RAP source was used to design two types of Superpave mixes, namely, Oklahoma S3 base and Oklahoma S4 surface course. Four mixes containing different percentages of RAP, namely, 25 and 40% RAP for S3 base courses and 0 and 10% RAP for S4 surface courses, were designed and tested. It was found that at lower temperatures, the mix containing a lower RAP content was stiffer, as indicated by higher creep compliance and indirect tensile strength values. At higher temperatures, however, the mix containing a higher content of RAP was also stiffer. Furthermore, the measured creep compliance values were compared with current predicted compliance values. The influence of RAP content on thermal cracking resistance was also evaluated through thermal stress analysis within the mechanistic framework.