Low-temperature crack resistance of stone matrix asphalt mixtures under chloride salt dry-wet cycles

Abstract

Given the current insufficient understanding of the low-temperature crack resistance performance and crack evolution patterns of asphalt mixtures under chlorinated salt wet-dry coupling environments, this study aims to fill this knowledge gap. We employed SMA-13 asphalt mixtures modified with different dosages of polyester fibers (0 %, 0.3 %, 0.35 %, 0.4 %, 0.45 %, 0.5 %) and tested their low-temperature crack resistance by conducting 0 to 8 wet-dry cycles in pure water and a 13.25 % chlorinated salt solution, to explore the improvement effect of polyester fibers on the performance of asphalt mixtures in such environments. The results indicate that an increase in the number of wet-dry cycles leads to a degradation of crack resistance performance across all fiber dosages, especially under the influence of chlorinated salt wet-dry coupling, where the adverse effects are more pronounced. Fracture energy analysis further confirms that 4 and 6 cycles of wet-dry cycling are effective indicators for evaluating the attenuation of low-temperature crack resistance under the long-term impact of wet-dry cycling. Through Digital Image Correlation (DIC) and Scanning Electron Microscopy (SEM) analyses, this study reveals the significant impact of wet-dry cycling on crack evolution and identifies 0.4 % as the optimal dosage of polyester fibers, significantly enhancing the low-temperature crack resistance performance of asphalt mixtures.