Research on material selection and low-temperature anti-cracking mechanism of hydraulic asphalt concrete panels in the alpine region

To solve the problem of asphalt concrete panel cracking at low temperatures, this study proposes to use crumb rubber as a modified material for asphalt in the impermeable layer of asphalt concrete panels and to investigate the anti-cracking performance of crumb rubber modified asphalt concrete (CRMAC) in water conservancy projects in different low-temperature environments. Taking matrix asphalt concrete (MAC), CRMAC, and SBS modified asphalt concrete (SBSMAC) as the research objects, the cracking resistance performance of the three kinds of asphalt concrete under different low-temperature conditions were comparatively analyzed by using ultra-low-temperature (−35°C) small beam bending test, which reveals the damage mechanism of asphalt concrete's low-temperature cracking and damage process; the failure temperatures of the three kinds of asphalt concrete were accurately quantified by the thermal stress restrained specimen test (TSRST), and combined with the Pearson correlation coefficient method to determine the evaluation criteria of asphalt concrete low-temperature performance. The results show that the low-temperature crack resistance of CRMAC is better than the other two asphalt concretes under the same temperature conditions. Its failure temperature reaches −43°C, which meets the low-temperature demand for asphalt concrete panels in alpine regions. This study aims to improve the low-temperature cracking resistance of asphalt concrete impermeable panels, provide new ideas for the selection of asphalt concrete panels, and lay the foundation for the application of CRMA in water conservancy projects, and open up new ways to solve the problem of waste tire accumulation. •Proposed using CRMAC as impermeable layer materials for asphalt concrete panels.•Different types of asphalt: Karamay 70, SBS, and crumb rubber modified investigated.•Using TSRST to measure failure temperatures of asphalt concrete: CRMAC −43℃.•Small beam bending test temperature range: −35℃∼−10℃.•The cracking damage mechanism of asphalt concrete at low temperatures is revealed.