ABSTRACT 
Laboratory experiments have shown that the properties of a 80/100 penetration grade bitumen had improved when modified with an oil palm fruit ash (OPFA). The results of consistency and rheological tests have shown that OPFA-modified bitumen (OPFA-MB) met the requirements for Superpave Performance-Based binder 70–16 and Penetration-Grade binder 60/70, and therefore, it can be classified as binder PG 70–16 and a 60/70 penetration grade bitumen. In addition, several tests such as the Marshall test, indirect tensile modulus resilient (MR), static uniaxial creep test, wheel tracking test, static-immersion and boiling water test and drain-down test were carried out on stone mastic asphalt (SMA) mixes, both using unmodified- and OPFA- MB. It was observed that presence of OPFA-MB improves the SMA mixes stability, resilient modulus and rut resistance compared to the unmodified one. The use of OPFA-MB also provides a good adhesive to the aggregate. This material is found to be an excellent alternative material for a fiber replacement in SMA mixes.      
Keywords: Oil palm fruit ash, stone-mastic asphalt, rheology, rutting, resilient modulus, adhesive.