Fatigue performance of geotextile-reinforced graded crushed stone base layers in asphalt pavements

To investigate the influence of geotextile-reinforced graded crushed stone (GRGCS) on the reflective-crack fatigue performance of asphalt pavement, this study used an improved moving-wheel fatigue test and scaled composite specimens. A rutting tester applied repeated moving loads, while an artificial joint and asymmetric supports simulated joint-related differential movement and a voided support condition. Four configurations were evaluated: Group A, the unreinforced control; Group B, with a geotextile above the graded crushed stone layer; Group C, with a geotextile below that layer; and Group D, with geotextiles at both interfaces. Compared with Group A, Group B increased the mean cycles to crack initiation by 69.46%. Group C changed the observed crack path from a shear-associated inclined trajectory to a more vertical, tensile-associated trajectory and increased the mean final fatigue life by 59.38%. Group D produced the longest mean fatigue life, 162.50% higher than that of Group A, together with the smallest shear deformation. The results demonstrate that geotextile position affects crack initiation, propagation morphology, deformation, and fatigue life.