Self-healing master curves of bituminous binders: a non-linear viscoelastic continuum damage framework

In this paper the viscoelastic continuum damage theory was used to investigate the damage and self-healing potential of bituminous binders, considering the effects of rest temperature, thixotropy, and non-linearity. Experimental testing was carried out by using a procedure in which continuous oscillatory shear loading was imparted to the specimens with the inclusion of a single rest period under multiple temperature conditions. Quantification of self-healing included the determination of material integrity gained and damage parameter recovered after the rest period. Such parameters were calculated by excluding time-dependent and non-linear biasing effects, which were directly evaluated by means of a distinct set of experiments. Results were modelled by using the so-called self-healing master curves, constructed by applying the linear viscoelastic time-temperature shift factors. These self-healing master curves are intended to be used as straightforward tools for the prediction of the self-healing response of neat and polymer modified binders in various time-temperature combinations.