<p>Fracture of rock particles is important in many applications like mining, mineral comminution, unbound granular materials (UGMs) for railway and road structures. The latter application is the main interest presently, as fracture of rock particles in UGMs affects the UGMs performance and may compromise structural integrity of a pavement, potentially leading to premature road failures. Therefore, it is important to assess their resistance to aggregate fracture accurately. In this study, a new statistical fracture model for particle fracture, based on the results of single particle crushing tests, is introduced to investigate aggregate fracture. The proposed model is tested for UGMs composed of three different aggregate types: brick, granite and a volcanic material and its results are compared with other widely used fracture force models. The performance of the models is also investigated by simulating uniaxial monotonic compression tests on UGMs with different aggregate size distributions using the Discrete Element Method (DEM) and comparing the results with experiments. Fracture at two different load levels for three different particle size distributions are investigated for each material. One particle size distribution at one load level is used to identify the contact law parameters for each material, and single particle breakage test are used to identify the fracture force model parameters. The DEM models with a new fracture force model agrees well with the macro-mechanical behaviour observed in experiments and exhibits the highest degree of correlation to fracture results obtained from experiments.</p>