Effects of GTR and Treated GTR on Asphalt Binder and High-RAP Mixtures

Abstract

One approach to produce environmentally friendly and cost effective asphalt mixtures is to use more readily available recycled materials like reclaimed asphalt pavement (RAP) and rubber. In this study, ground tire rubber (GTR) and treated ground tire rubber (TGTR) were added to an asphalt binder and to high RAP content mixtures. Rutting and fatigue characteristics of the modified binder were evaluated.GTR and TGTR improved the rutting and fatigue performance of the asphalt binders. A suspension agent helped reduce the degree of separation. GTR was introduced into the binder and the resulting rubberized binder was used to prepare the mixtures. The TGTR was directly added to the mixture. TGTR mixtures were mixed and compacted at lower temperatures compared with GTR mixtures. The dynamic modulus, reflective cracking performance, low temperature cracking, and rutting and moisture susceptibility were evaluated for the mixtures. GTR and TGTR made improved resistance to rutting, moisture susceptibility, and low temperature cracking. According to the Texas overlay test, the GTR and TGTR might not improve the mixture’s resistance to reflective cracking.