Innovative chromogenic materials for pavement life extension: Modeling study of surface temperature of sustainable asphalt pavement

Asphalt pavements are widely used in highways due to their good performance and relatively low construction and maintenance costs. However, the black color of asphalt induces that the sunlight is not reflected but absorbed, which raises the temperature of the asphalt pavement and impacts its long-term durability. Thermochromic materials are substances that can reversibly change their colors in response to temperature. This innovative is to incorporate thermochromic materials into asphalt to improve the durability of asphalt pavement. By fine-tunig the threshold temperature, the material can potentially produce a larger solar reflectance at high temperatures. Consequently, this will help reduce the temperature on the surface of asphalt pavement. The long term goal is to make pavement more reflective during summer and more solar absorptive during winter. In this paper, FEM simulation is conducted to study the influence of thermochromic materials on the surface temperature of asphalt pavement. The results show that the surface temperature of asphalt pavement doped with thermochromic materials is significantly lower compared to that of conventional asphalt pavement. In the meanwhile, conventional asphalt pavement underwent higher magnitude of temperature variations compared with thermochromic asphalt pavement. The decreased surface temperature and lower heat flux of thermochromic pavement both contribute to better pavement performance.