Linear viscoelasticity and fatigue life: Relationships between properties of asphalt binders and corresponding mixtures

Abstract

Asphalt mixture performance is affected by binder’s and aggregate’s properties. Mixtures and binders share some Linear ViscoElastic (LVE) properties when small number of loading cycles and strains are considered. It is still unclear how fatigue properties relate among different scales. Three binders associated to three mixtures were characterised by stiffness (ASTM D 7175 and AASTHO T342) and fatigue (AASHTO TP107) standard tests. For stiffness modelling, complex modulus was represented by the 2S2P1D model, while the SHStS (Shift-Homothety-Shift in time-Shift) transformation was used to relate the material scales. S-VECD (Simplified Viscoelastic Continuum Damage) model was used to describe fatigue. Six out of the nine 2S2P1D model constants fitted to the binder’s complex modulus data could be kept the same for their corresponding mixtures. SHStS proved suitable for material upscaling, showing that mixtures inherit most of their LVE behaviour from binders. Although it was difficult to relate S-VECD model constants among the different scales, classical fatigue parameters (γ6 and ε6, strain levels for fatigue failure after a million cycles) suggested good correlation between binders’ and mixtures’ fatigue properties.