Rutting Characteristics of Bio-Asphalt Binder Based on the Multiple Stress Creep Recovery Test Results

The phenomenon of asphalt binder aging can lead to various failures, such as rutting in the asphalt mixture. Rejuvenator materials are used to mitigate asphalt binder aging. Bio-asphalt, as a binder modified with bio-waste materials, offers environmental benefits and enhances asphalt binder aging. Recent research has indicated that bio-oils improve the effectiveness of asphalt binders at moderate and low temperatures, but they may exacerbate the susceptibility to rutting at high temperatures. This study employed rice bran oil (RBO) as an environmentally friendly rejuvenating agent in asphalt binder and leveraged the benefits of nano-CaO to enhance asphalt binder performance at high temperatures. Based on the findings of this study, The binder sample with 5% RBO and 3% nano-CaO exhibited superior performance in the multiple stress creep recovery (MSCR) test, and rutting susceptibility decreased by 13-34% compared to the unmodified samples. Conversely, utilizing 5% RBO without nano-CaO increased rutting susceptibility by 35-50%.