ASSESSMENT OF PARTIAL REPLACEMENT OF CEMENT WITH OIL PALM FIBER ASH (OPFA) IN CONCRETE PRODUCTION

Abstract

Sustainability of cement consumption provides opportunity to research into possibility of alternative and locally sourced cementitious material like oil palm fiber ash (OPFA) considered for this research investigation. The study aims at evaluating the characteristic properties of OPFA as a partial replacement for cement in concrete. The oil palm ash was prepared through controlled incineration and tests carried out to ascertain the pozzolanic property. OPFA were included at 0%, 5%, 10%, 15% and 20%, replacement by weight of cement in concrete mixtures (with design ratio of 1 : 1½ : 3 (cementitous : sand : granite). Slump test was used to establish the workability properties of fresh concrete and the cast concrete cubes were cured by exposure to air and immersion in water before subjected to compressive strength test. The slump showed that workability of OPFA concrete decreases as OPFA content increases, indicating that the inclusion demands more water content than normal cement concrete. Compressive strength of OPFA-concrete was observed to increase with curing age and decrease with increasing percentage of OPFA, and the optimum compressive strength of 20.49 N/mm² was obtained at 5% replacement level at 28 days curing, also the split tensile strength results was low expressing the low tensile bonds in concrete formation. The regression analysis of compressive strength for both air and water cured specimen employs a model of the type ? = a Ln(t) + b, where a and b are regression parameters, the model results provide good comparison with experimental values with 95% reliability. The study concluded that OPFA has the potential of being used as partial replacement of cement up to 10% replacement level and higher percentage can be employed in lightweight, cost-effective and low strength concrete

Keywords: Cementitous, OPFA, Compressive strength, Concrete cubes, Curing days