Abstract:Effect of nano SiO2 with modified surface on the physical and ultraviolet aging resisance of bitumen was investigated. The compatibility between nano SiO2 and bitumen was studied by high temperature stability test. The results show that the compatibility between nano SiO2 and bitumen is improved significantly by surface modification of nano SiO2. With the same nano SiO2 content, the difference values of softening point as well as the nano SiO2 contents in the upper and lower sections of the toothpaste tubes for the bitumen with unmodified nano silica are lower than that for the bitumen with unmodified nano SiO2. Compared with modified nano SiO2, the softening point and viscosity of bitumen are increased by adding modified nano silica more significantly, moreover, the penetration is less reduced and the ductility of bitumen is increased by 10℃. In addition, by using modified nano silica the viscosity aging index of the bitumen is reduced significantly after ultraviolet aging indicating good ultraviolet aging resistance of bitumen with surface modified nano SiO2.