A novel design method for stone mastic asphalt (SMA) for airports in cold regions

Thermal cracking has long been a major concern for airport bituminous pavements in cold regions since it is in close connection with the safe operation of aircraft. This study aims to develop a design method for low-temperature performance-oriented airport bituminous mixtures. The research work mainly includes selecting design parameter, establishing design procedure, and verifying design method. The test and analysis results showed that the destructive tensile strain (DTS) of low-temperature splitting test was sensitive to the change of bitumen content, and can accurately characterize the thermal cracking resistance of the bituminous mixtures. Therefore, DTS was suitable as the design parameter, and its critical values were proposed for different climatic conditions. Furthermore, a new design procedure was established by incorporating DTS into the designs of gradation and optimum bitumen content. Through tests under different low temperature environments, it was verified that the design method can significantly improve the anti-cracking ability of designed bituminous mixtures. This study provides a new idea for enhancing the thermal cracking resistance of airport bituminous pavements in cold regions in terms of bituminous mixture design.