Abstract
Aiming to improve the performance of asphalt pavement in seasonal freezing regions, systematic research of rubber asphalt was conducted in macro and micro aspects. The specific rubber asphalt was synthesized according to the special requirements of the seasonal freezing regions. Moreover, the optimum dosage of rubber powder was proposed through asphalt mixture performance experiments. The macromechanical properties of the rubber asphalt under different temperatures were evaluated according to the Strategic Highway Research Program (SHRP). The composition and microstructure of the rubber asphalt were tested by using Fourier Transform Infrared Spectroscopy (FTIR) and AFM analyses. In addition, the modification mechanism of rubber asphalt was also investigated. The results showed that the optimum dosage of rubber powder for the seasonal freezing region was 20 %. The rubber asphalt with 20 % rubber powder could resist shear deformation at high temperatures as well as improve the low-temperature performance of aged asphalt. Furthermore, the macro performance was enhanced, which was related to the increments of nanoadhesion between rubber powder and asphalt. The composition and microstructure of the rubber asphalt could be affected by the swelling of the rubber particles. Therefore, it was concluded that the synthesized rubber asphalt is suitable for seasonal freezing regions.