Review on application of phase change materials in asphalt pavement

Phase change materials (PCMs) can regulate the temperature in asphalt pavement and minimize temperature-related problems, such as rutting and thermal cracking, because of their ability to store and release latent heat. Suitable PCMs can also enable additional road surface functions, such as snow melting ability, freeze-thaw cycle resistance, and heat island reduction. These functions are helpful in achieving intelligent, green, and sustainable transportation systems. Although the research on PCMs for asphalt pavement has been carried out for more than 10 years, a systematic material system and mature application technology have not yet been formed. The main reasons for restricting the development of this technology include the lack of suitability between the PCMs and asphalt pavement, the quantitative characterization of phase change temperature regulation property, and the evaluation of the effect of phase change energy storage on improving pavement performance. Although the published review has made a comprehensive summary of the existing research, it has yet to identify the key restricting the development of this technology and carry out a review and discussion based on it. To grasp the development status of the application of PCMs in asphalt pavement, sort out the development needs and break through the technical barriers, this study systematically summarizes the preparation and performance of PCMs for asphalt pavement, compares the performance and evaluation methods of asphalt mixtures with different PCMs, and summarizes the numerical simulation methods of phase change asphalt mixtures. Finally, this study presents potential approaches to address critical technical issues and discusses possible future research.