Evaluation of quantum dot composite graphene/Titanium oxide enhanced UV aging resistance modified asphalt

The long-term ultraviolet radiation of asphalt pavement leads to performance degradation, which seriously affects the service life. However, inorganic nanoparticles as anti-ultraviolet aging modifiers can only respond to some ultraviolet light, resulting in not high absorption rate of ultraviolet light. In this study, a variety of nanoquantum dots were introduced to modify graphene/titanium dioxide to further improve the ultraviolet absorption capacity of inorganic nanoparticles and slow down the aging of asphalt pavement caused by ultraviolet light. The effect and mechanism of the special heterojunction structure formed by a variety of quantum dots on the aging resistance and rheological properties of asphalt were investigated. The results show that the introduction of various quantum dots improves the ultraviolet absorption capacity of nano-TiO2. Although the thermal stability of nanographene/titanium dioxide composites decreases, its initial decomposition temperature is much higher than the test temperature of the asphalt mixture. From the macroscopic rheological test, the nanographene / titanium dioxide composite material further expands the improvement effect on the high-temperature rheological properties of asphalt, and secondly slows down the low-temperature crack resistance of nano-TiO2 modified asphalt. From the microscopic test, the introduction of various quantum dots greatly reduces the sulfoxide index (SI), carbonyl index (CI) and root mean square roughness Sq of modified asphalt, effectively slowing down the aging effect of ultraviolet light on asphalt, and ensuring the service state of asphalt pavement in a complex environment.