Properties of Self-Compacting Concrete Containing Palm Oil Fuel Ash and Rice Husk Ash

Palm fuel ash (POFA) and rice husk ash (RHA) are usually disposed to open areas and landfills without treatment, resulting in environmental problems. Both materials fulfilled the criteria as pozzolanic material, thus can be used as substitutes to cement. This paper presents the comparison in the fresh and hardened properties between self-compacting concrete (SCC) containing POFA and RHA. The SCC mixtures were produced based on water/binder ratio of 0.6. Both POFA and RHA were introduced in concrete replacing 0%, 10%, 20% and 30% of cement by weight. The fresh SCC was tested for three (3) fresh properties including filling ability, passing ability and segregation resistance. Meanwhile, the hardened properties of concrete were tested for its compressive strength. The fresh properties of SCC incorporating POFA and RHA fulfilled all the requirements of SCC which include the filling ability, passing ability and segregation resistance. Meanwhile, SCC containing RHA had higher compressive strength than the SCC containing POFA for all different replacement level. This is because RHA had higher SiO2 content than POFA, thus promote more pozzolanic reaction to improve the strength of concrete. Furthermore, the optimum replacement level of POFA and RHA in SCC are 10% and 20%, respectively. However, the compressive strength of both SCC containing POFA and RHA were still lower than the control SCC. It is suggested that the SCC containing POFA and RHA to be cured for longer period to achieve better or equivalent strength to the control SCC.