Evaluating Indirect Tensile Strength (ITS) of Dry-Processed Rubberised Stone Mastic Asphalt (SMA) Mixture

The utilisation of crumb rubber through a dry process is a practical and economical method to confront the challenges of tyre recycling and environmental sustainability. This study aimed to identify the mechanical behaviour of the rubberised SMA mixture. Therefore, the Response Surface Methodology (RSM) was used to investigate the effect of independent variables such as binder content, CR content, curing time and CR size on mechanical response variables. Analysis of Variance (ANOVA) based on Indirect Tensile Strength (ITS) of the asphalt mixtures was performed to analyse the data. A quadratic polynomial model effectively fitted the experimental results and reliably predicted performance outcomes with an acceptable level of accuracy. This study reveals that alongside independent variables, their interactions are pivotal, as evidenced by the varying behaviour of ITS under different interaction scenarios. Recognising these interactions is crucial for precise design, ensuring efficient performance in rubberised SMA pavements.