Using DSR and MSCR tests to characterize high temperature performance of different rubber modified asphalt

Rubber modified asphalt (RA) has been generally used to improve the high temperature performance of asphalt mixtures in the past decades. This study is to investigate the high temperature performance of rubber modified asphalt in ways of Dynamic Shear Rheometer (DSR), Multiple Stress Creep Recovery (MSCR) and statistical analysis of variance (ANOVA), and an optimum index for evaluating the high temperature performance is recommended based on the experimental results. The DSR test results show that the addition of rubber powder into the neat asphalt leads to a significant improvement of high temperature performance. Multiple Stress Creep Recovery (MSCR) test results confirm that the accumulated strain remarkably decreases when lower rubber fineness or lower grade neat asphalt is used to produce rubber modified asphalt. Based on the ANOVA, it is recommended that the indexes of Jnr and R% can be used to characterize high temperature performance in terms of the rutting resistance of different rubber modified asphalts.