A Numerical Study of the Effect of Aggregate Fracture on the Unbound Granular Materials Response under Triaxial Loading

Abstract

The performance of unbound granular materials (UGMs) made from crushed rock plays a critical role in the service life of roads. While experimental evidence indicates that aggregate crushing and abrasion significantly affect UGM stiffness and permanent deformation, the precise relationship between aggregate strength and UGM performance remains unclear. This is particularly important when using aggregates of marginal strength in road construction. This study investigates the impact of aggregate breakage on UGM behavior under triaxial loading, using the Discrete Element Method (DEM) for computational analysis. The model examines how aggregate breakage influences UGM response for two different types of aggregates. The DEM results are compared with experimental data from the literature. Findings show that particle fracture significantly influences the maximum deviatoric stress that the UGM can endure under two different confining pressures, highlighting the importance of aggregate strength in determining UGM performance.