Use of Viscoelastic Continuum Damage Theory to Correlate Fatigue Resistance of Asphalt Binders and Mixtures

Abstract

The objectives of this study were to evaluate the fatigue resistance of asphalt binders in relation to their composition and establish the correlation of the fatigue property of asphalt binders with that of mixtures using the viscoelastic continuum damage (VECD) approach. Materials used in the research incorporated reclaimed asphalt pavement, recycled asphalt shingles, warm-mix technologies, and two grades of base binder. Dynamic modulus and direct-tension cyclic fatigue tests were used to assess the linear viscoelastic and fatigue properties of mixtures, respectively. Asphalt binders were extracted, and their linear viscoelastic and fatigue characteristics were determined using frequency sweep at multiple temperatures and the linear-amplitude sweep (LAS) test, respectively. The LAS data were analyzed using the revised VECD formulation, and the parameter denoted as ALAS was proposed as an indicator of the fatigue resistance of asphalt binders. Mixtures’ fatigue resistance was represented by the newly developed parameter of material fatigue sensitivity (MFS). The experimental evidence suggested that the proposed ALAS parameter was a valid indicator of the fatigue resistance of asphalt binders. Further, a reasonable correlation was identified between the fatigue resistance of asphalt binders and mixtures, as represented respectively by ALAS and MFS.