Discrete element simulation of crack resistance of asphalt pavement with geotextile reinforced graded gravel base

To address reflective cracking in semi-rigid base asphalt pavements, conventional graded gravel transition layers are found to cause anisotropy errors in finite element simulations and be prone to plastic deformation; therefore, this study proposes a geotextile-reinforced graded crushed stone (GRGCS) base structure. A two-dimensional discrete element model (DEM) of five pavement structures was established using MATDEM to simulate shear deformation under jointed and joint-free conditions, combined with full-scale test road monitoring to investigate the GRGCS crack resistance mechanism. The main results are as follows: (1) the double-layer GRGCS structure optimizes force chain distribution, reducing the base’s maximum tensile strain by 71% and joint stress concentration by 52%, while exhibiting the strongest resistance to shear deformation; (2) full-scale testing verifies that GRGCS delays the initiation of reflective cracks to 180 days (an extension of 150 days compared with semi-rigid bases), with only non-reflective micro-cracks observed during service; (3) the double-geotextile scheme enables meso-scale force chain regulation, providing theoretical support for long-life asphalt pavement design with an anticipated 10-year service life. This study elucidates the GRGCS reflective crack inhibition mechanism via meso-scale force chain optimization. The double-geotextile scheme provides a reliable theoretical basis for long-life asphalt pavement design.