A probabilistic model for predicting the resistance of aggregates in asphalt mixes to fracture

Increased loads on asphalt pavements have lead to the development of asphalt mixes that rely on stone-on-stone contacts in resisting applied loads. These mixtures tend to experience high forces at the contact points that could cause aggregate fracture and make the asphalt pavements more prone to distresses such as cracking and permanent deformation. This paper introduces an approach to express the probability of aggregate fracture in asphalt mixes as a function of the contact bond strength and internal force distribution at the contact points. The internal force distribution was obtained using a discrete element model of the internal structure of asphalt mixtures subjected to loading. The contact bond strength was determined using statistical analysis of the results of a single aggregate crushing test. The developed approach can be used to determine the asphalt mixture design and aggregate properties that minimize fracture and achieve desirable mixture performance.