Mechanism and Performance Evaluation of Different Crumb Rubber Modified Asphalt

Abstract

This study aims to characterize the mechanism and performance of different crumb rubber modified asphalt including the desulfurized crumb rubber asphalt and the common crumb rubber asphalt. Component analysis and Gel Permeation Chromatography test were used to reveal the performance mechanism of different crumb rubber asphalt. Superpave tests were conducted for performance evaluation of different crumb rubber asphalt at the low and high temperatures. Separation test was conducted to compare the storage stability of different crumb rubber asphalt. Mix designs and performance tests were conducted to evaluate the high temperature rutting resistance, low temperature cracking resistance, moisture stability, and fatigue life of different rubber asphalt mixtures. The results show that the crumb rubber mainly exists in asphalt independently while most of the desulfurized rubber can be digested into asphalt and partially changes the components and microstructure of asphalt. The most obvious difference between the crumb rubber asphalt and the desulfurized rubber asphalt was observed for viscosities. The crumb rubber asphalt show better performance than the desulfurized rubber asphalt based on Superpave performance testing results, while the desulfurized rubber asphalt shows better storage stability. Compared to the crumb rubber asphalt mixture, the compaction temperature of desulfurized rubber asphalt mixture can be lowered by 10 to 20℃ to achieve the same performance requirements.