Investigation of influence factors on low temperature properties of SBS modified asphalt

- Show the key factors influencing low temperature properties of binder.
- Optimum modification scheme for SBS modified asphalt is investigated.
- Component distribution, thermal behavior and FTIR spectrum are presented.
- Rubber processing oil can supplement the loss of maltene fraction.
- Evaluate SBS modified asphalt mixture with TSRST test.

Styrene-butadiene-styrene (SBS) is widely used in asphalt modification and the investigations about SBS modified asphalt are focused on high temperature property, storage stability and the compatibility between SBS and asphalt. While the study on influencing factors on low temperature properties are not sufficient yet. In this paper, a systematical research was conducted to evaluate the influencing level of important factors such as SBS polymer type, SBS content, sulfur content and addition of rubber processing oil. Firstly, bending beam rheometer (BBR) test associated with Burger's model was used to evaluate the low temperature property and relaxation capacity. Furthermore, FTIR, GPC and DSC tests were conducted to investigate the chemical changes in SBS modified asphalt. At last, the low temperature performance of SBS modified asphalt mixture was investigated with thermal stress restrained specimen test (TSRST). In this paper, the optimum modification scheme of SBS modified asphalt binder and mixture was investigated and summarized. SBS polymer is swollen by saturates and aromatics which made the base binder lack of maltene fraction. While the further addition of rubber processing oil supplemented the maltenes which improved the low temperature property.