Damage characterization of high- and low-temperature performance of porous asphalt mixtures under multi-field coupling

Porous asphalt (PA) have attracted considerable interest due to their functional advantages such as significant water permeability and noise attenuation properties. Nevertheless, its vulnerability to damage significantly hinders its widespread application. Therefore, this paper aims to investigate the damage characteristics of PA's high- and low-temperature performance under the coupled effects of moisture and temperature. Firstly, Hamburg Wheel-Tracking Test (HWTT) and three-point bending tests were conducted on PA under different coupling conditions. Subsequently, its damage characteristics were analyzed using the three-stage permanent deformation model, logistic model, and two-way analysis of variance (ANOVA) method. The findings indicate that under dry conditions, PA-13 exhibits a linear decrease in rutting resistance within the temperature range of 40–60 °C, followed by a significant decrease at 70 °C. During immersion in water, PA-13 undergoes a second and third-stage rutting evolution process, with an accelerated creep rate observed at 70°C. High temperatures exacerbate the viscoelastic damage of PA-13, while multi-field coupling promotes the simultaneous occurrence of viscoelastic damage and stripping damage. Furthemore, the results of the two-way ANOVA indicate that moisture has a more significant impact on high-temperature performance damage. In addition, in a dry environment, the low-temperature crack resistance of PA-13 deteriorates with decreasing temperature, but there is little difference at −20 °C and −30 °C. This is attributed to PA-13 exhibiting flexible cracking at 0 °C and −10 °C, while undergoing brittle cracking at −20 °C and −30 °C. Additionally, the coupled effect of temperature and moisture reduces the damage tolerance of PA-13 and accelerates its cracking process. The results of the two-way ANOVA indicate that both low temperature and treatment methods have a statistically significant impact on low-temperature performance, with treatment methods having a higher degree of influence. The findings of this paper contribute to an in-depth understanding of the damage mechanism of PA-13.