Impact of Nano-TiO2 on the NO2 degradation and rheological performance of asphalt pavement

This research carried out the NO2 degradation performance and asphalt pavement performance of SBS modified asphalt with different content (0%, 1%, 2%, 5%, 10%) of nano-TiO2, and the impact of cationic surfactant were evaluated as well. The nano-TiO2 modified asphalt was prepared for Dynamic Shear Rheometer (DSR) test, Bending Beam Rheometer (BBR) test, Rolling Thin Film Oven Test (RTFOT) and Pressure Aging Vessel (PAV) test. And the high temperature performance, low temperature performance and aging properties were evaluated. Results show that the nano-TiO2 increased the rutting resistance of asphalt in high-temperature especially when the content increased from 0% to 1%, and it did not have a significant impact on low temperature cracking resistance. Secondly, this research developed an innovative photo-reactive and measuring system, and simulated the NO2 degradation environment based on field data of varies typical roadway sections. Then, this research conducted photo-catalytic degradation test of NO2 for asphalt mixture with 5% nano-TiO2 content. The analysis shows that there are reversible reaction between NO2 and N2O4, and results indicated that the asphalt mixture has exhibited NO2 degradation effects. This research provided a deep understanding for the road performance and engineering application of nano-TiO2 modified asphalt mixture. (C) 2019 Elsevier Ltd. All rights reserved.