Short-term resilient behaviour and its evolution with curing in cold in-place recycled asphalt mixtures

Abstract

This study evaluates the short-term resilient behaviour of cold in-place recycled (CIR) asphalt mixtures with bitumen emulsion when they are more similar to non-cohesive granular materials than to conventional hot mixtures. Gyratory compacted CIR specimens were manufactured using different proportions of bituminous emulsion and water, and dynamic triaxial tests were conducted at different curing times. The resilient moduli were obtained experimentally and fitted using three numerical models. Characteristic nonlinear elastic behaviour and an increase in stiffness with curing time were observed. Water loss during curing and stiffness increase were found to be related. Mixtures with 2.50% residual bitumen and 2.75% added water showed the best short-term stiffness evolution.