The influence of the mass ratio of crumb rubber and waste cooking oil on the properties of rubberised bio-rejuvenator and rejuvenated asphalt

With the increasing emphasis on RAP recycling technology in recent years, a waste rubber/oil (WRO) asphalt rejuvenator was self-developed by mixing crumb rubber (CR) with waste cooking oil (WCO) at high temperatures. This study was designed to determine the effect of the ratio of rubber to oil (RRO) on the properties of WRO rejuvenators and rejuvenated asphalt binders. Results indicate that the WRO sample with higher CR content exhibited better storage stability and contained more soluble macromolecular polymers. The effect of the RRO on solubility of CR was more significant than that of the reaction time. WCO served the main role in asphalt softening, while CR mainly contributed to the aging resistance of asphalt. Asphalt rejuvenated by WRO with a greater RRO exhibited better elasticity and rutting resistance. In terms of sulfoxide functional group content, increasing the RRO of the WRO was beneficial to the rejuvenation effect.