Effect of crumb rubber size on the performance of rubberized asphalt with bio-oil pretreatment

To evaluate the effect of crumb rubber size on asphalt performance, four crumb rubbers were chosen to prepare the composite modified asphalt via the pretreatment of crumb rubber by bio-oil under microwave heating. After short-term aging, the temperature sweep test, the MSCR test, LAS test and the cigar tube test were performed to evaluate the high-temperature performance, fatigue property and the storage stability of the composited asphalt, respectively. All Jnrs from the composite modified asphalt were less than 2.0 kPa−1 at 3.2 kPa. The crumb rubber size was positively correlated with the fatigue life. The relatively lowest segregation index was observed in the composite modified asphalt containing 40 mesh (0.38 mm) crumb rubber. It is concluded that the rubber size affects the performance of the composite modified asphalt. The pretreatment of bio-oil on crumb rubber facilitated the swelling and depolymerization of crumb rubber in the melt asphalt.