Performance evaluation of stone mastic asphalt (SMA) mixtures with palm oil clinker (POC) as fine aggregate replacement

The palm oil industry has been projected to increase annually, hence resulting in a large number of waste materials being dumped into landfills. In order to decrease the adverse effects of these wastes on the environment, they may be used to substitute conventional aggregates in building roadway pavements. Having that said, this study assessed the effect of using palm oil clinker (POC) as a substitute to fine aggregate on the mechanical properties of SMA mixtures. A range of asphalt mixtures were prepared by replacing the fine aggregate with different POC contents (0%, 20%, 40%, 60%, 80%, and 100%). Additionally, 50% of palm oil fuel ash (POFA) was used as filler in the asphalt mixtures. Resilient modulus, wheel tracking, dynamic creep, indirect tensile strength, and Cantabro durability tests were conducted on all the prepared asphalt mixtures. The results signified the suitability of POC for 100% substitution of fine aggregate in SMA mixture, as it enhanced resilient modulus, resistance to rutting, tensile strength, and resistance to moisture damage. Conclusively, SMA20 mixture between 40% and 60% displayed better mechanical properties, when compared to other mixtures.