Response of binder-filler systems into and beyond linear viscoelastic domain: Modeling and healing efficiency

Abstract

This study is devoted to present insights into linear and nonlinear viscoelastic responses as well as the healing efficiency (HE) of binder-filler systems. To this aim, linear viscoelastic (LV) rheometric results were collected via implementing temperature and frequency sweep measurements, while for probing the nonlinear viscoelastic (NLV) response, large-amplitude oscillatory shear test was executed for various strain maxima. A parallel rheological framework assembled from 2 Yeoh models and hyperbolic-sine flow law, hereinafter abbreviated as 2Y-HS model, was explored to emulate the stress response for LV and NLV behavior of the binder-filler systems. In addition, a strain-dependent healing protocol was developed to test the HE of materials for varying strain-amplitudes. The tested binder-filler systems were blends of a plain binder and two mineral fillers, hydrated lime (HL) and silica fume (SF), added one at a time at different rates based on the best-practice limits. The binder-filler mastics undergone different behaviors into and beyond linear viscoelastic domain (LVD). The 2Y-HS model has efficiently constituted the rheometric results in a manner that elucidates the link between the stresses and strains for both LV and NLV behaviors. The proposed HE protocol showed its efficacy to evaluate the healability of materials at varying rest periods and stretch magnitudes. The damage-mending process at small-amplitude strains tended to improve better, and worst HE was attained as the strain level increases. The richer the asphalt binder with mineral filler, the less the HE is registered; however the binder-HL system is predisposed to heal much more than SF mastics.