(to be submitted for journal publication)
S.-H Song, M.P. Wagoner, G.H. Paulino and W.G. Buttlar
Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Newmark Laboratory, 205 North Mathews Avenue, IL 61801, U.S.A.
Abstract
Abstract:
Recent work with fracture characterization of asphalt concrete has shown that a cohesive zone model provides insight into the fracture process of the materials. However, a current approach to measure fracture energy, i.e. area of force versus crack mouth opening displacement (CMOD), for asphalt concrete overpredicts the magnitude of the energy. Therefore, the delta-25 parameter, which was inspired by the insightful delta-5 concept of Schwalbe and co-workers, is proposed as an operational definition of a crack tip opening displacement (CTOD). The delta-25 measurement is incorporated into an experimental study of validation of its usefulness with asphalt concrete. Once the delta-25 parameter is deemed relevant, the parameter is utilized to measure fracture energy. The work presented herein validates and verifies the delta-25 parameter for asphalt concrete, describes the experimental techniques for utilizing the delta-25 parameter, and presents three-dimensional cohesive zone model simulations with the newly developed cohesive law. The integration of the delta-25 parameter and new cohesive law has provided further insight into the fracture process of asphalt concrete with good agreement between the experimental results and numerical simulations.