Low-temperature crack resistance of basalt fiber-reinforced asphalt mixtures: Effects of fiber content and distribution

Basalt fibers (BFs) have gained significant attention for their effectiveness in enhancing the crack resistance of asphalt mixtures. While research on basalt fiber-reinforced asphalt mixture (BFRAM) primarily focuses on fiber content, type, and size, the distribution characteristics of fibers remain underexplored. This study employs an integrated approach utilizing computed tomography (CT) imaging, dynamic mechanical analysis (DMA), semicircular bending (SCB) tests, and discrete element method (DEM) simulations to systematically evaluate the influence of BF content and distribution patterns on the low-temperature fracture performance of BFRAM. The key findings reveal: (1) The Weibull distribution effectively models the BF distribution in asphalt mastic, and CT analysis shows BFs primarily concentrate in sample centers, with consistent X- and Y-direction patterns. (2) At the mastic scale, 4.0 % BF reduces glass transition temperature by 2.8℃ for better low-temperature elasticity; 0.4 % BF is optimal for the asphalt mixture’s crack resistance. (3) The 3D DEM model overcomes the limitations of existing modelling methods, accurately capturing fiber reinforcement and advancing numerical simulations. These findings offer valuable insights for optimizing BFRAM design in low-temperature applications.