Stability improvement technology of SBS/crumb rubber composite modified asphalt from Xinjiang China

Abstract

Previous studies have shown that single modified asphalt is difficult to meet the requirements of road quality at complex service environments. The service environment of roads in Xinjiang, China is harsh, and the stability of modified asphalt in Xinjiang is poor, which cannot meet the requirements of road quality. For the purpose of solving the technical problems such as poor stability after modification of local asphalt in Xinjiang China, improving the comprehensive performance of modified asphalt and recycling waste tire crumb rubber, SBS/crumb rubber composite modified blended Xinjiang asphalt was prepared. Based on the basic performance of asphalt, microstructure test, aging test and rheological test, the stability improvement methods of composite modified asphalt were studied systematically, and the mechanism of asphalt stability improvement was confirmed. The SBS/CR-S asphalt and SBS/CR-N asphalt composite modified asphalts which were suitable for hot and cold regions in Xinjiang were determined. The environmental durability of SBS/CR-S asphalt, SBS/CR-N asphalt, SBS asphalt and rubber asphalt used commonly in Xinjiang under different conditions of light-thermal and freeze-thaw were compared and evaluated. The results showed that the stability improvement methods such as asphalt blending and additives compounding supplemented the lightweight components of asphalt, which promoted the reaction and cross-linking between modifier and asphalt, and improved the stability and comprehensive performance of asphalt. After stability improvement, the 5 °C ductility of SBS/CR-N asphalt and SBS/CR-S asphalt was 32.6 cm and 31.5 cm respectively, and the segregation softening point difference was 1.5 °C and 1.8 °C. After light-thermal and freeze-thaw aging, SBS/CR-S asphalt and SBS/CR-N asphalt still exhibited outstanding high and low temperature performance. SBS/CR-S asphalt and SBS/CR-N asphalt had excellent storage stability, high and low temperature performance and environmental durability.