Experimental Study on NO2 Photocatalytic Degradation on Sand Fog Seal with Nano TiO2

Abstract

The paper discusses the performance and durability of a new type of functional pavement degrading exhaust gas with sand fog seal as carrier and loaded with photocatalysis material. In order to explore the characteristics of the new technology for sand fog sealed layer loaded with photocatalysis material, the laboratory pavement exhaust gas absorption and reaction test device was fabricated. Degradation rate and degradation amount were used as the evaluation indexes of tail gas degradation. Simulated research on the initial state of functionalized treatment of rutting specimens and the degradation effect after simulated wheel rolling by using a given concentration of NO2 gas to simulate automobile exhaust. Then comparing with traditional surface type (water-based coating) and mixed (replacing part of mineral powder). The results show that under the same proportion of photocatalyst (nano-TiO2), all the three processes can degrade NO2, and the effect of fog sealed and water-based coating is basically the same, which is about 37% higher than that of the mixed. By comparing the amount of degradation, it was found that the amount of degradation of the mixed was lower under the same conditions. The mixed took much longer time to reach equilibrium than the other two processes, which means the degradation effect was not obvious in a short time. It is considered that most of the nano-TiO2 is inside the Specimen, and only the portion of the surface that is exposed to ultraviolet light reacts. Comparing the degradation effects before and after rolling, it was found that the loss amount of degradation of the sand-containing seal layer was greater than that of the mixed type, but the overall degradation effect was 32.55% higher than that of the blending type. The loss of degradation of the water-based coating is the largest after rolling. It is considered that the asphalt is softened due to the temperature rise during the rolling process, and the water-based coating is wrapped, and the durability is poor.