Abstract:In order to improve the crack resistance of recycled asphalt mixture, the nano-SiO2 and SBS are selected as the modifiers to respectively prepare the nano-SiO2 modified recycled asphalt mixture, SBS modified recycled asphalt mixture, SBS/nano-SiO2 compound modified recycled asphalt mixture and common recycled asphalt mixture. Several recycled mixtures are tested including the disk tensile test, small-beam test and fatigue test to determine the crack resistances of the different asphalt mixture. The results show that the low temperature performance and fatigue performance of recycled asphalt mixture are improved by using the modified asphalts. And the overall crack resistance of SBS/nano-SiO2 compound modified recycled asphalt mixture is the best. Therefore, it is proposed that when the high content of old asphalt pavement material is adopted, the use of SBS/nano-SiO2 compound modified asphalt will obviously improve the overall crack resistance of the concrete.