Application of asphalt pavement with phase change materials to mitigate urban heat island effect

Urban Heat Island (UHI) effect does harm to the urban residents living and social environment, and changing of the underlying surface characters is one of the major reasons caused UHI. Asphalt pavement widely used in the city road enhances the UHI effect because of its strong heat absorption characteristic. The existing techniques and measurements of asphalt pavement cannot mitigate the influence of the asphalt pavement temperature on the urban air, only belongs to the passive response. According to the latent thermal characteristic and temperature control function of phase change materials (PCM), this study mix the PCM into asphalt mixture. The thermal conductivity of asphalt mixture with PCM obviously increase and the specific heat also increase under different temperature. The PCM change the thermo-physical characteristic of asphalt mixture. Comparing the samples´ temperature after the heating and cooling process, the temperature change rate of asphalt mixture with PCM decrease, and the emergence of extreme temperatures were delayed, and the duration of the extreme temperatures were shorted. The results indicated that mixing PCM into asphalt mixture can initiatively improve the heat changing between pavement surface and environment, reduce the interaction, and mitigate the UHI effect.