**5. Conclusions**


has the best relaxation characteristics; different relaxation times indicate different crack resistance, the longer the relaxation time, the worse the crack resistance. However, less relaxation time (less viscosity) leads to a large viscous flow in a very short time, creating a large rutting, which is one of the most serious issues in asphalt pavement on heavy-duty roadways.

**Author Contributions:** Investigation, S.M. and T.M.; Methodology, L.F. and Y.Z.; Experiment, Z.D.; Writing—original draft, S.M. and L.F.; Writing—review and editing, X.Z. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Applied Basic Research Project of the Ministry of Transport, gran<sup>t</sup> number 2013319781140, and project ZR2020QE271 supported by Shandong Provincial Natural Science.

**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.
