Study on the Effect of Crack Density and Micro-Cracking Block Size of In Situ Softening Semi-Rigid Base

Reflection cracking in semi-rigid bases is a widespread distress that undermines highway safety. Priority should be given to this issue to ensure the normal performance of large-scale semi-rigid base asphalt pavements that have reached the end of their service life. At present, scholars have deeply studied and applied the theory of pavement surface layer fracture damage. However, the study of semi-rigid bases only focuses on pavement temperature influence, crack prediction, and reflection crack retardation, and there is a lack of further research on crack-related characteristics. Building on the novel concept of in situ softening for semi-rigid bases, we employ finite element analysis to quantify how transverse crack density affects overall stiffness and derive targeted softening strategies accordingly. By establishing the base micro-cracking treatment cracking block-size influence model, this study analyzes the load-bearing characteristics of cracking blocks of different sizes and recommends optimal block dimensions. This study provides practical guidance for the treatment of semi-rigid bases with maximum efficiency by expanding the application of fracture mechanics at the microscale and providing practical guidance for the high-value rehabilitation of semi-rigid bases.