*Article* **Investigation of the Rheological Properties and Chemical Structure of Asphalt under Multiple Aging Conditions of Heat, UV and Aqueous Solution**

**Yingxue Zou <sup>1</sup> , Ling Pang <sup>1</sup> , Shi Xu 2,3,\* , Shaopeng Wu <sup>1</sup> , Miao Yuan <sup>4</sup> , Serji Amirkhanian <sup>5</sup> , Haiqin Xu <sup>1</sup> , Yang Lv <sup>1</sup> and Xiang Gao <sup>1</sup>**


**Abstract:** During the service period, asphalt materials are affected by various natural factors, including heat, ultraviolet light, oxygen and moisture, etc., resulting in the reduction of pavement performance, the increase of pavement distress and shortening of service life. This study aims to investigate the aging performance of asphalt under multiple aging conditions of heat, UV and aqueous solution. Thermal-oxygen aging, UV aging and hydrostatic erosion tests were carried out sequentially on asphalt. The rheological properties, chemical structure and element composition of asphalt were characterized before and after aging, and the effect mechanism of multiple conditions was discussed. The results show that the multiple conditions of heat and UV can increase the rutting resistance and weaken the cracking resistance of asphalt. However, the effect degree of UV decreases gradually with the deepening of aging degree. Additionally, the effect of water on the physicochemical properties is less than that of UV; however, water can increase the sensitivity of physicochemical properties to UV. In summary, this study explored the short-term cycling effect of heat, light and water on asphalt and provided an idea for simulation test of asphalt under multiple aging condition.

**Keywords:** asphalt; thermal-oxygen aging; UV aging; moisture damage; rheological performance; chemical structure
