Research on microstructure and repeated creep properties of polymer modified asphalt

Three polymer modified asphalts(SBS modified asphalt, crumb rubber modified asphalt and compound crumb rubber modified asphalt) widely used in Inner Mongolia and northwest region were analyzed. The scanning electron microscope was used to observe modifiers distribution in asphalt and microcosmic appearance of asphalt. It was shown that the interface between modifiers and asphalt had good compatibility. Then the repeated creep tests for three modified asphalts at different temperatures and stresses were carried out by dynamic shear rheology instrument. Cumulative strain and the viscous portion GV of creep stiffness were analyzed. The results indicate that they have the same change law when loading number, temperature and stress magnitude change. Crumb rubber modified asphalt has the lowest sensitivity to temperature, the smallest cumulative strain and the largest GV under the same condition, so it has the best high-temperature stability property, followed by compound crumb rubber modified asphalt.