Low-Temperature Crack Resistance of Basalt Fiber-Reinforced Phase-Change Asphalt Mixture Based on Digital-Image Correlation Technology

DaoLu Tiaowen Cailiao (DTC) phase-change materials are important materials for improving the temperature adaptation of asphalt pavements. In order to improve the low-temperature crack resistance of asphalt pavements after adding DTC phase-change materials, basalt fiber-reinforced DTC phase-change asphalt mixtures with different basalt fiber dosages were prepared, and their mechanical properties, horizontal strain, and crack characteristics were analyzed using semicircular bending tests combined with digital-image correlation technology. The study showed that the basalt fiber increased the fracture strength of the phase-change asphalt mixture, delayed its damage time, improved its deformation capacity, reduced the crack development rate and damage degree of the interface, and enhanced its low-temperature crack resistance. The enhancement of low-temperature crack resistance of phase-change asphalt mixtures increased and then decreased, and the best effect was achieved when the dosage of basalt fiber was 3%o, which delayed the damage time of phase-change asphalt mixtures by 42.53 s, slowed down the crack expansion rate by 54.23%, and reduced the fractal dimension (D) and damage factor (D-f) by 4.32% and 29.83%, respectively. In conclusion, basalt fibers can enhance the low-temperature crack resistance of phase-change asphalt mixtures, and the optimal dosage of basalt fiber is 3%o. Also, both D and D-f showed a positive correlation pattern with K-IC, but D-f was more closely related to K-IC, which shows that the new index D-f based on the image analysis method and MATLAB software is reliable. (C) 2023 American Society of Civil Engineers.