The durability of asphalt mixture with the action of salt erosion: A review

Performance deterioration of asphalt pavement is mainly caused by the action of natural forces in combination with repeated vehicle load. The salt erosion environment (salt solution, salt fog, humidity, wind, air temperature, ultraviolet (UV), dry-wet/freeze-thaw cycles, et al.), particularly in the areas around eastern and western in China, causes significantly negative impacts on the asphalt mixture. This paper reviews the performance damage of asphalt mixture under salt erosion and multi-factor coupling. On the basis of analyzing the mechanism of the performance damage of asphalt mixture under salt erosion, the application of computer-aided processing methods in the research of salt erosion degradation on asphalt mixture are discussed. Then, the laboratory simulation devices, test methods, evaluation indexes and the damage prediction model of asphalt mixture with salt erosion are categorized and summarized. This review finds that the performance of asphalt mixture extremely deteriorates under the condition of salt erosion and multi-factors coupling, and the deterioration mechanism of asphalt mixture under salt erosion is related to crystallization effect. Computed tomography (CT) combined with image processing technology and numerical simulation has developed into an important tool to detect internal damage of asphalt mixture. The traditional and newly proposed laboratory devices and methods can be utilized to simulate the external service environment of asphalt pavement. However, there are still some differences between laboratory experiment and actual pavement environment. The durability evaluation system of the asphalt mixture under salt erosion and multi-factor coupling is incomplete and needs to be further explored. Finally, the main challenges and consideration in the further research are discussed. This review provides a useful reference for improving the durability of asphalt mixture in salt enrichment areas in China.