**4. Conclusions**

In this paper, based on temperature shear test and bending beam rheological test, the influence of SBS content on the high and low temperature performance of modified asphalt is preliminarily analyzed. The calibration curves of SBS content based on rutting factor and creep slope are presented and its defects are pointed out. Meanwhile, the calibration curve of determining SBS content by FTIR is established, and the orthogonal test is designed to explore the influence of additives sulfur and rubber oil on the determination results. The main conclusions are as follows:


**Author Contributions:** Conceptualization, G.X. and X.C.; methodology, X.G.; validation, X.C., Y.Y.; formal analysis, X.G.; investigation, G.X.; resources, X.C.; data curation, X.G.; writing—original draft preparation, G.X.; writing—review and editing, X.G. and Y.Y.; supervision, X.C.; project administration, X.C.; funding acquisition, X.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by National Natural Science Foundation of China (No. 51778136), Technology Research and Development Program of China State Railway Group Co., Ltd. (K2020G032). And the APC was funded by Technology Research and Development Program of China State Railway Group Co., Ltd., Beijing, China.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
