Effect of Varying the Proportions of Palm Kernel Shells on the Properties of Concrete Interlocks Cured in Air

This study investigates the properties of concrete interlocks produced using palm kernel shells (PKS) as a partial replacement for conventional building materials, such as granite chips (GNC), to determine the optimal PKS content that meets acceptable standards. Samples of materials required were collected, measured in masses and batched in a mix ratio of 1:2:3. The palm kernel shells replacement varies with granite chips from 0% PKS with 100% GNC to 100% PKS with 0% GNC at 10-unit intervals using water to cement value of 0.5. A total of eleven (11) samples of concrete interlocks were molded, cured for 28days in the air, measured and subjected to compressive strength test. The highest compressive strength of the samples was achieved at 30% PKS with 70% GNC combination, with a compressive strength of 15.13MPa. The sample produced at 30% PKS exceeded the minimum strength requirement of 15.00MPa specified in BS 8110 (1997) and outperformed the compressive strengths of samples from factory X (13.00MPa) and factory Y (10.00MPa). However, the sand mixing ratio in this study was 25% higher than the BS 8110 (1997) recommendation but 50% lower than that used in factory Y. To meet standard specifications, the palm kernel shell content in concrete interlocks should not exceed 30%. Future studies should focus on roughening the smooth surfaces of the shell particles to enhance bonding with other concrete aggregates.