Properties and phase separation characteristics of modified recycled asphalt with activated crumb rubber and waste cooking oil

Microwave-activated crumb rubber (ACR) was prepared by microwave activation, diffe-rent asphalt binders were prepared by regulating the addition amounts of ACR and WCO with ACR as the modifier, WCO as the rejuvenator and aged asphalt (RA) as the raw material, and the effects of the addition amounts of ACR and WCO on the basic technical indexes of the asphalt binders, high- and low-temperature properties, anti-fatigue cracking performance and storage stability were investigated. In addition, the mechanism of formation process of asphalt binders was also analyzed. The results showed that when the addition mass fraction of WCO was 7% and 10% of RA, and the addition mass fraction of ACR was 12%-25% of RA, WCO, as a rejuvenator, could not only effectively restore the performance of RA, but also promote the full swelling of ACR through the solubilization effect, thereby improving the comprehensive performance of asphalt binders. With the increase in ACR addition amount, high-temperature permanent deformation resistance and anti-fatigue cracking performance of asphalt binders improved gradually; with the increase in WCO addition amount, low-temperature cracking resistance of asphalt binders improved significantly. When the addition mass fractions of ACR and WCO were 18% and 10%, respectively, the storage stability of asphalt binder was the best. The ACR phase and RA phase in asphalt binder formed a tight “button” three-dimensional network structure, which reflected the excellent synergistic modification effect between ACR and WCO.