'Study on microcosmic properties of waste tire rubber powder

Modified asphalt with waste tire rubber powder was prepared by using orthogonal experimental design of four levels and four factors. Aging test of film oven was carried out with the optimized combination of rubber powder modified asphalt.The performance changes of different asphalts were evaluated from macroscopic point of view, and chemical components and revolution of rubber modified asphalt were analyzed from microscopic point of view by three major indicators of asphalt, infrared spectroscopy, four component analysis and differential thermal test. The results showed that the optimal ratio of modified asphalt was 17% （mass fraction, the same below） of rubber powder amount ,180 ℃of mixing temperature, 1/6 of modifier mass ratio and 4% of plasticizer amount. The shape and position of the characteristic infrared absorption peak of asphalt modified with rubber powder remained unchanged, but intensity changed. Meanwhile, the content of chemical components was changed. The components of saturated and aromatic decreased, but resin and asphaltene components increased. The addition of rubber powder reduced degradation rate of the asphalt, increased initial degradation temperature and final residue content, and improved thermal stability of the asphalt.