TENSILE STRENGTH PROPERTIES OF CORN COB ASH AND KENAF FIBRE REINFORCED CEMENT COMPOSITES FOR SUSTAINABLE DEVELOPMENT

This study investigated the tensile strength properties of composites of Ordinary Portland cement (OPC) replaced with Corn cob ash (CCA) at different proportions and kenaf fibre reinforcement in the composite matrix. Seventy-five (75) concrete cylinders of sizes 100 mm (diameter) × 200 mm (height) were used for the mechanical property considered. The OPC 0% CCA replacement and 7.5% kenaf fibre reinforcement were used as the control experiment and OPC with CCA replacement of 5%, 10%, 15% and 20% and 7.5% fibre reinforcement were tested for split tensile strength properties at 7, 14, 21 and 28 days curing age. The mix ratio adopted for this work was 1:3 while the crushed quarry dust used allowed water/cement ratio of 0.6 to attain workability. The control (0% kenaf, 0% ash) has higher split tensile strength values that increased from 7 to 28-day curing age than those which contained kenaf with CCA. The tensile strength was found to increase with curing age from 7 to 28 days while the trend showed decrement as the CCA increased from 5 to 20% in the matrix. Values of 2.58, 2.09, 1.60 and 1.47 N/mm2 were recorded for 5%, 10%, 15% and 20% ash contents respectively at 7.5% kenaf fibre inclusion in 28 days curing age. The study has shown that at 5% optimum replacement of cement for corn cob ash, the composite developed could be used for low cost housing components such as roofing sheets, floor and wall tiles for sustainable development in developing countries.