Rehabilitation of Asphalt Pavement to Improvement the Mechanical and Environmental Properties of Asphalt Concrete by Using of Nano Particles

Dealing with the pollution released into the air by vehicles is a major concern for many countries around the world. There is an increasing trend toward environmental considerations as well as road logistics issues, resulting in doing experiments on new materials, which can help reducing the amount of pollutants in the atmosphere. In this research, the photo catalytic properties of Nano TiO2/SiO2 used over the asphalt roads in order to absorb the pollution substances from the atmosphere are investigated. The above mentioned compound reacts with UV light and oxidizes the pollutant particles including nitrogen oxides (NOx) as well as volatile organic compounds (VOC). In this method, the sol-gel technique was used to produce photo catalyst based on TiO2/SiO2. One purpose of this research is to examine the photo catalytic properties of the compound when it is used in a hot mix asphalt (HMA). Another aim of the study is to find and describe both rheological and mechanical characteristics of the hot mix asphalt (HMA) as well as the Nano modified agents. The resulting asphalt would have the advantages of HMA, including lower energy requirements and less emission during production, while having photo catalytic characteristics of TiO2/SiO2 to absorb and decompose the organic and inorganic air pollutants. The outcomes of the tests showed that adding the Nano TiO2/SiO2 modifier to the asphalt binder effectively removed NOx particles from the air and enhanced the rheological properties of bitumen. It also enhanced the hardness and viscosity of the pavement, while reducing its penetration and fatigue life. When TiO2/SiO2 was sprayed as a water based coating, the efficiency of NOx reduction ranged between 41 and 63%.