The Research On NO_x Degradation Performance Of Asphalt Pavement Coating By Nanometer-TiO₂

In the rapid development of today’s global economy,the flying growth of vehicle population is facilitated by the sharp expansion of demand for transportation,leading to the seriously excessive levels of automobile exhaust content in the road environment.So,environmental pavement technology with the function of degenerating automobile exhaust has become an important research project in road engineering.Because of the different degree of harm to human body from the nitrogen oxides in vehicle exhaust,through the development of road surface and road side coating by nano-TiO2,the goal of improving the air quality of road environment will be achieved.Firstly,the definition and characteristics of nanometer materials and the definition,composition and function of the coating were introduced,and the photocatalytic mechanism of nano-TiO2 and the influence factor of photocatalytic activity were briefly narrated.Based on the research of the basic properties of nano-TiO2,and the use function of road surface and road side coating,appropriate component were choosed.Comprehensive analysis of the dispersion method of nanometer materials,blending method was choosed for the proposed method,meanwhile,the phenomenon of agglomeration of nano-particle was handled.Combining with the results of relevant personnel,the comprehensive dispersing approach,which is adding surfactants and the combination of mechanical dispersion and ultrasonic dispersion,was finally decided to adopt.Secondly,based on the domestic and overseas research and development about photoreactor,in view of the defects of previous results and the field monitoring results of automobile exhaust gas,a photocatalysis cycle test system with the controllable change to environmental impact factors was developed.There were many features in the system,including simulating various UV irradiation intensity,high resolution of gas detection system,the recycled gas and two sets of gas detection system in the meantime.So the whole process of photocatalytic reaction can be accurately described.Finally,the self-developed reaction test system was used to carry out the photocatalytic degradation experiment based on the proposed test steps.On the one hand,the photocatalytic degradation effect of the road surface coating by nano-TiO2 in different dosage of silane coupling agent and UV irradiation intensity were researched,and the economic benefit of the application of this material was evaluated.On the other hand,the photocatalytic degradation effect of the road side coating by nano-TiO2in different dosage of surfactant was studied,and the economic benefit of the application of this paint was evaluated.The research results of this paper is helpful to the improvement of the environmental protection technology of asphalt pavement and application.Meanwhile,the theory basis is provided for the exploitation and the study on performance characteristics about the road surface and road side coating,as well as the popularization and application of engineering works,with great value in environmental protection.