Essential and Plastic Works of Ductile Fracture in Asphalt Binders

Abstract

Currently, no satisfactory asphalt binder test method exists that can relate properties measured in the laboratory to fatigue performance in service. The loss modulus of the binder, G*sinδ, as proposed by the Strategic Highway Research Program, is a rheological parameter that measures the energy dissipated within the homogeneous binder at low strains under dynamic conditions. A number of publications have reported that this binder parameter provides little correlation with the susceptibility of the asphalt concrete to fracture at high strains in the nonlinear regime under simulated in-service conditions. The essential work of the fracture method, an energy-based testing approach used for the fracture characterization of ductile materials, was explored. Given that asphalt is a ductile material at ambient temperatures, it is only reasonable to assume that the essential work of fracture method yields valuable information with likely use in fatigue performance ranking. The binders investigated showed a wide range of essential and plastic works of fracture at ambient temperature and a single rate of loading. Although only six binders were evaluated, their works of fracture were contrasted with other properties.