Research Of The Environmental Effects And Construction Technology Of Thermal Reflective Asphalt Pavement

The proportion of Asphalt pavement in the construction of China’s highways and urbanroads is continuously rising in recent years. But Asphalt is a heat-absorbing material andasphalt pavement surface temperature may raise up to60℃when the temperature is high insummer. On the one hand, Rut affect driving comfort and safety, on the other hand, the hightemperature of the urban road easily lead to pedestrian hot anxious and thermal discomfort etc.at the same time exacerbate the urban "heat island effect". Domestic and foreign researchershave carried out the correlational researches for the high temperature hazards of asphaltpavement and raised some technical measures in which, improving the albedo of pavement isan effective way of cooling technology and is still developing in China. Based on theindependent development of solar heat-reflective paint for road, to assess its efficacy inenvironmental improvement and combined with test road research the constructiontechnology of solar heat-reflective coating.Firstly,set the heat balance equation of the asphalt pavement under the light and heat ofthe asphalt pavement environment. Through laboratory experiments, thermal reflectiveasphalt pavement interior cooling rate can amount to15~20℃. Outdoor cooling by theenvironment in which the impact of the asphalt pavement, but the cooling effect is still about10℃. According to the different characteristics of the AC surface layer and the the SMAsurface layer, considered two aspects of cost and cooling effect factors, the recommendedamount of coating are0.6kg/m2and0.8kg/m2. Secondly, according to the road surface andenvironmental radiation heat transfer and convection heat transfer principle, combined withthe road surface temperature forecast data and ambient air temperature data, establish acomputational model of the thermal effect of asphalt pavement, road surfaces quantitativeevaluation of the environmental thermal effects. Various factors affecting the thermal effectof asphalt pavement are analyzed, the results found that the impact is not big change on thedaytime thermal effect of asphalt pavement thermal conductivity, but the heating effect ofthe asphalt pavement at night decreases with the decrease of the coefficient of thermal conductivity. The reflectance of the road surface is the most critical factor with the increaseof road surface reflectance, the heating effect of the road dropped significantly. Finally, inorder to verify the laboratory research and to promote the practical application of theheat-reflective asphalt pavement, studied the heat reflecting coating construction technologyand quality control method of paving the heat-reflective asphalt pavement test road. The testresults shown that the maximum cooling capacity of the test road reached10°C, anti-slidingperformance meet the requirements of safety, and heat reflecting coating also has certainwaterproof performance.