ABSTRACT

This research embodies analysis of using Crushed Palm Kernel Shells (CPKS) as partial replacement for fine aggregate in concrete. The research is aimed at determining the relevant concrete properties and to reduce the weight of concrete in high rising structures that fall in normal concrete envelope. Various percentages replacement of fine aggregates of 0%, 10%, 20%, 30%, 40% and 50%, respectively of CPKS concrete were tested for 1:3:6, 1:2:4 and 1:1:3 concrete mix ratios. Concrete samples with no CPKS (0% replacement) served as the control experiment. The batching was by weight. Palm kennel Shells were crushed to river size of 4.75mm (No 4) sieve and then incorporated into the concrete. Ninety-six (96) concrete cubes of each concrete mix ratios, measuring 150mm x 150mm x 150mm, were tested for the compressive strength at 7, 14, 21 and 28 days respectively. The research revealed that the CPKS acted as a retarder in the concrete because of its nature of consolidation. Water cement ratio increased with the increase in the percentage of the CPKS. The nominal mixes of 1:3:6, 1:2:4 and 1:3:6 at 28 days curing with 0%, 10%, 20%, 30%, 40% and 50% partial replacement of fine aggregate yielded average compressive strengths in N/mm² of  20.88, 20.21, 19.35, 18.36, 17.32, 16.49;  25.08, 24.41, 23.47, 22.65, 21.28, 20.25 and 26.93, 26.42, 25.51, 24.42, 23.76, 22.69 respectively.