Use of ash derived from oil-palm waste incineration as a cement replacement material

The production of palm oil creates large quantity of solid waste by-products. Empty oil-palm fruit bunches discharged from the mill are currently being disposed of by burning in an incinerator. After combustion, a substantial amount of highly caustic ash is produced which creates problems of disposal. This study examines the feasibility of using the ash as a cement replacement material. The experimental results indicate that blended cement containing ash derived from oil-palm waste shows satisfactory setting times and soundness test results. Workability of concrete incorporating the ash is categorized as good, and no segregation was observed. The effects of ash addition on concrete densities and water absorption are insignificant. Compressive strength of the concrete decreases with the ash content in the cement. Up to 10% by weight of ash addition, no adverse effect on the strength was observed for the cubes cured for 1 year. The results suggest that the ash could possibly be blended in small amounts with ordinary Portland cement for concrete making without detrimental effects on long-term strength property.