Non-linear viscoelastic model based ranking of modified binders for their rutting performance

Abstract

Rutting is one of the most common distresses observed in bituminous pavements. A number of test procedures, associated parameters, and correlations have been developed for the binder and the mixture to evaluate their rutting performance. In this investigation, the rutting performance of an unmodified, and three modified binders (Elastomer, Plastomer and Crumb rubber) was evaluated separately for the binders and mixtures. Creep-recovery and stress relaxation experiments were carried out on binders in the temperature range of 46–70 $${^{\circ }}$$ C. The mixtures were subjected to dry rut wheel testing at 50 and 60 $${^{\circ }}$$ C. A nonlinear viscoelastic fluid model was used to capture the response of the binder. Using the material parameters identified separately for creep-recovery and stress relaxation experiments, the apparent viscosity was computed for each binder at different stress levels. It was seen that the ranking of mixtures evaluated from rut wheel testing was captured by the apparent viscosity predicted using the non-linear viscoelastic model.