Property of Photocatalytic Asphalt Mixtures Based on the Characteristics of Gaseous and Particulate Pollutants

摘要

Road transportation is a source of air pollution in cities, especially harmful in haze weather condition. On road pollutants tests were conducted by an emission measurement system designed for pavement photocatalytic characteristics. Four typical asphalt mixtures with photocatalytic property, so called self-cleaning asphalt concrete (SCAC), were studied. A new photocatalytic testing system was simulated based on the pollutants concentration data collected on real-world conditions. Two photocatalytic indexes, relative decomposition rate and degradation capacity, were proposed to evaluate photocatalytic property of self-cleaning asphalt concrete. Four typical asphalt mixtures included AC-13a asphalt mixture (AC-13a), AC-13b asphalt mixture (AC-13b), open-graded fraction courses (OGFC), and high-voids asphalt concrete (HVAT), were prepared with SBS/TiO2 modified bitumen. The performance of SCAC was investigated by cracking resistance, rutting resistance, and moisture susceptibility. The results showed that degradation capacity of CO is approximately 20 times of HC and NO for SCAC. The air voids of SCAC exposed to ultraviolet ray contributes to the Photocatalytic indexes in the simulated system in this research. In addition, the SBS/TiO2 modified bitumen does not reduce the high- or low-temperature property of SCAC.