Performance Assessment of Asphalt Binder Modified with Batu Pahat Soft Clay as an Eco-Friendly Additive

This study aims to evaluate the impact of incorporating Batu Pahat Soft Clay (BPSC) into conventional asphalt binder at varying proportions: 2-, 4-, 6- and 8%-BPSC by weight of asphalt binder. A comprehensive laboratory investigation was carried out, including consistency test, Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Shear Rheometer (DSR), Scanning Electron Microscopy (SEM) tests. In terms of rutting, the parameter G*/sin δ increased significantly by nearly 839.25% at 45 °C and 196.67% at 75 °C for the 4%-BPSC binder compared to the base binder. The Multiple Stress Creep and Recovery (MSCR) test further confirmed the BPSC effectively reduce the residual strain by over 55%. FTIR analysis indicates a physical interaction between the BPSC and the binder, with no evidence of new chemical bond formation. Based on overall findings, the 4%-BPSC modification is identified as the optimal percentage for achieving balanced improvement in binder performance, contributing to more sustainable asphalt solutions.