Research on the performance of temperature responsive asphalt mixture with thermochromic material

The surface temperature of asphalt pavement can be exceedingly high in summer while the heat conserved in the pavement tends to be rapidly lost in winter, which leads to rutting and cracking distresses, respectively. Thermochromic material with its ability to change colour subject to temperature variations, was used in this study to control road surface temperature. Three types of thermochromic materials including the red, blue, and black ones, were applied to the 70# and SBS asphalts at the contents of 5% by weight to prepare 70#+ and SBS+ asphalts, respectively. Different test methods were employed to verify the high-temperature, low-temperature, water stability, and fatigue performances of the 70#+ and SBS+ asphalt mixtures. The study reveals thermochromic material can be used to reduce the road surface temperature in summer, and to delay the reduction of road temperature in winter. 70#+ and SBS+ thermochromic asphalt mixtures have a significant improvement in high-temperature performance. The low-temperature crack resistance of the mixture is improved after the blend of blue and black thermochromic materials, while the opposite is true after mixing with the red thermochromic one. The water stability of the thermochromic mixtures is slightly better than that of base asphalt. Furthermore, the observed fatigue performance of SBS + Blue asphalt mixture is remarkably improved. Therefore, considering the overall balance of performance improvements, the blue thermochromic material is recommended in this study.