Abstract:In this paper, the Bending Beam Rheometer test(BBR) and Semi-Circular Bend test (SCB) were conducted to study the low temperature performance of TB composite SBS modified asphalt and mixture with different contents of crumb rubber (5%, 10%, 15%, 20%) and SBS (2%, 3%, 4%), and the correlation of different low temperature performance indexes was analyzed. The results show that, the TB crumb rubber modified asphalt has excellent low temperature performance, with the increase of crumb rubber content, the low temperature PG and thermal stress of asphalt decrease, and the low temperature crack resistance of mixture was enhanced. For TB composite SBS modified asphalt, with the increase of crumb rubber content, the improvement effect on low-temperature performance of asphalt is significant, but lower than that of the corresponding amount of TB modified asphalt; However, with the increase of SBS content, the improvement on low temperature performance of asphalt is not obvious, and the low temperature crack resistance of mixture is deteriorated. The addition of SBS will decline the low temperature performance of TB asphalt. For TB modified asphalt, the low temperature PG index can reflect the low temperature performance of asphalt and mixture, while for TB composite SBS modified asphalt, the low temperature performance cannot be evaluated by a single low temperature PG index, and it needs to be evaluated together with other indicators.
