The utilisation of crumb rubber through a dry process addresses the challenges of tyre recycling and promotes environmental sustainability. This study aimed to investigate the mechanical behaviour of the Crumb Rubber Stone Mastic Asphalt (CR-SMA) mixture. The response surface methodology (RSM) is adopted to explore the impact of independent variables, such as binder content, Crumb Rubber (CR) content, processing time, and CR size, on the variables controlling the mechanical response of the mixture. To comprehensively evaluate the data, the moisture susceptibility, resilient modulus, and fracture energy of the asphalt mixtures are studied using Analysis of Variance (ANOVA). The study successfully achieved an optimum CR-SMA mixture design by enhancing resistance to moisture damage, resilient modulus, and fracture energy, contributing to an improved understanding of the mechanical performance criteria. A quadratic polynomial model aligned with experimental results is proposed, providing reliable predictions of the material performance with an acceptable level of accuracy. These findings offer a valuable roadmap for future strategies in construction, maintenance, and rehabilitation, particularly within the domain of rubberised SMA pavements.

Stone Mastic Asphalt (SMA), Recycled tyre rubber, Dry-processed rubberised asphalt mixture.