Characterization and performance prediction of ALF mixtures using a viscoelastoplastic continuum damage model

This paper presents an argument for the utilization of constitutive models to predict fatigue performance. The argument is made within the framework of the viscoelastoplastic continuum damage (VEPCD) model. Four asphalt concrete mixtures, each a part of an ongoing study at the Federal Highway Administration's Accelerated Loading Facility (FHWA ALF), are characterized using this model. Polymer-modified asphalt binders are used with three of the four mixtures. Comparisons of linear viscoelastic, viscoelastic damage and viscoplastic properties are provided. Further, it is shown that the time-temperature superposition principle with growing damage is not limited to mixtures with simple asphalt binders and applies even to those with polymer-modified asphalt binders. The VEPCD model is shown to accurately predict material behavior over a range of conditions different than those used to characterize the model. Finally, experimental results are presented which show that fatigue performance is a complicated phenomenon dependent on many factors that may not be taken into account easily in current empirical procedures.