Preparation and Investigation of NiTi Alloy Phase-Change Heat Storage Asphalt Mixture
Biao Ma, Kun Wei, Xiaofeng Huang, Weibo Shi, S. S. Chen, Yongping Hu, Haozhe Shi
Abstract
Adding phase-change material (PCM) into the asphalt mixture has the potential to solve the temperature-related problem of asphalt pavement. During the phase transformation, NiTi alloy is still solid with good physical and mechanical properties. Therefore, no leakage and volatilization would occur, which are common problems occurring in the application of other kinds of PCMs. Equal volumes of NiTi alloy phase-change energy-storage particles are used to replace fine aggregates with corresponding particle diameter to prepare NiTi alloy phase-change heat storage asphalt mixture in the research. The admixture of NiTi alloy phase-change energy-storage particles could reduce the water stability of the asphalt mixture, but the adverse effect was not significant. When the phase change of NiTi alloy energy-storage particles occurred because of an increase in environment temperature, the heating rate of asphalt mixture was reduced due to the phase-change heat storage effect of NiTi alloy phase-change energy-storage particles. If there was more admixture, then the rate at which the mixture heats up would be slower. The indoor stimulated thermoregulation test showed that when the substitution rate of NiTi alloy phase-change energy-storage particles was 12% by weight, the maximum temperature difference between NiTi alloy phase-change heat storage asphalt mixture and ordinary asphalt reached 4.3°C.