Temperature responses of asphalt mixture physical and finite element models constructed with phase change material

Temperature changes of pavement structure have significant influence on the internal stress, strain, and deformation characteristics of the pavement structure. For example, rutting occurs in high temperature range and pavement cracks when its temperature is low. This yields failure and reduces the service life of the pavement structure. Phase change material, PCM, which is a new type of additive for pavement engineering, has been studied for regulating the working temperature of pavement structure. By storing or releasing thermal energy via phase change process, the PCM is able to maintain the temperature of pavement structure in a relatively narrow range. In the present study, outdoor asphalt mixture model constructed with and without PCM were established. The outdoor model was directly exposed to the environment and the temperature distribution inside the outdoor model was measured by using temperature sensors. The specific heat capacities of asphalt mixture mixed with and without PCM were determined by calorimetric method, which is simple and reliable. Based on the outdoor asphalt mixture model, the corresponding finite element model was established by using ANSYS, and the temperature distribution inside the finite element model was determined according to the measured specific heat capacity, density, thermal conductivity of the asphalt mixture, and the meteorological data which were used for determining the boundary conditions. Comparison between the calculated and actual measured temperature values was made. The results show that the calculated temperature values had good agreement with the measure ones, based on which the accuracy of material parameters and boundary conditions were validated. The results of the present study can lay the foundation for calculating the temperature field of pavement structure constructed with PCM and investigating the application of PCM in road engineering.