Binder- and Mixture-Level Evaluation of Rutting Predictors in Asphaltenes-Modified Asphalt

This study investigated the use of asphaltenes as an additive to enhance the rutting resistance of asphalt binders. To this end, a crude oil-derived asphalt binder was modified by blending in 12 % asphaltenes by weight. The multiple stress creep recovery (MSCR) test using a dynamic shear rheometer (DSR) showed that the modified binder had significantly lower non-recoverable creep compliance (J_nr), indicating improved rutting resistance, with values consistently below 0.5 kPa-1 – meeting standards for extremely heavy traffic. Stress sensitivity also decreased substantially, highlighting the stabilizing effect of asphaltenes. Additionally, the frequency sweep (FS) test at 1 rad/s (corresponding to high-temperature conditions) showed that the modified binder had a rutting parameter G*/sinδ values nearly seven times higher than the neat binder. Furthermore, the Hamburg wheel-track (HWT) test at 60 °C showed a 4.1-fold increase in rutting resistance index (RRI) for the modified mix, with no moisture sensitivity observed.