Assessing and Predicting Damage to the Service Performance of Asphalt Mixtures under Snow-Melting Thermal Fatigue

In winter, when electric heating pavements are melting snow and ice, the asphalt concrete often experiences freeze-thaw cycles that can easily lead to thermal fatigue damage to the pavement. Therefore, in this study, the temperature change state of the asphalt pavement during snow melting was simulated using an indoor heating-cooling cycle test, and the service performance of the asphalt pavement after snow-melting thermal fatigue damage was analyzed. The degree of damage to the service performance of stone mastic asphalt (SMA-16) during the heating-cooling cycle was quantitatively assessed using ultrasonic detection technology, and a prediction model between ultrasonic velocity and the damage coefficient of the service performance of the asphalt mixture was established. The results showed that the heating-cooling cycles caused thermal fatigue damage to the road performance of the asphalt mixture. Compared to the pavement asphalt mixture without snowmelt treatment, after undergoing 20 heating-cooling cycles, the porosity of the asphalt mixture increased by 5.25%, Marshall stability decreased by 3.03%, low temperature splitting strength decreased by 3.90%, and residual stability decreased by 4.41%. After the heating-cooling cycles of the asphalt mixture, the waveform was distorted. As the number of heating-cooling cycles increased, the wave velocity and amplitude gradually decreased. Compared to the traditional bridge decks, the road performance damage coefficient of conductive rubber composite bridge decks increased by no more than 11% after five years of snow-melting service. Although active electrical heating for snow melting may accelerate freeze-thaw damage to the pavement, this can be effectively mitigated by precisely controlling the pavement’s high temperature limits. The research results can provide a basis for predicting the service life of electrically heated snow-melting asphalt pavements and compensate for the shortcomings of the existing electrically heated pavement design system.