Performance Evaluation of SBS Modified Asphalt Mixture Rejuvenated by Multifunctional Compound Rejuvenator

The development of multifunctional compound rejuvenator (MCR) that not only can soften the aged asphalt matrix but also is capable of repairing the residual styrene-butadiene-styrene (SBS) copolymer network structure is paramount in achieving a better rejuvenation effect on the SBS polymer modified asphalt (SBSMA) in reclaimed pavement materials. In this research, the rejuvenation efficiency of an MCR that consists of epoxidized polybutadiene resin, epoxidized soybean oil (ESO), and maleic anhydride was evaluated at the scale of asphalt mixture. The comparisons of high-temperature stability, low-temperature anticracking capability, fatigue performance, moisture damage, and aging performance were conducted on original, aged, and rejuvenated SBSMA mixtures. The results indicated that MCR can effectively repair the SBS polymer network, whereas ESO, as a traditional rejuvenator, shows few effects on the damaged SBS polymer structure. MCR has similar rejuvenation effects to ESO in terms of recovering the stiffness, low-temperature cracking, and moisture resistances of aged SBSMA mixture. Notably, MCR shows a huge advantage over ESO when it comes to fatigue lifetime and aging resistance of rejuvenated SBSMA mixture.