COARSE

Concrete is one of the most widely used construction materials in Nigeria due to its strength, durability, and versatility. However, the increasing cost of granite and the environmental impact of quarrying have created the need for alternative, sustainable materials. At the same time, palm kernel shell (PKS), a by-product of palm oil processing, is generated in large quantities and often disposed of as waste, leading to environmental pollution. This study investigates the suitability of palm kernel shell as a partial replacement for granite in Grade 20 concrete.Granite was partially replaced with PKS at 0%, 10%, 20%, and 30% by weight. The physical properties of PKS, including specific gravity, bulk density, and aggregate impact value, were determined. Concrete mixes were produced and tested for workability using the slump test, as well as fresh and hardened density. Concrete cube specimens were cast and cured for 7, 14, and 28 days before compressive strength testing in accordance with relevant British Standards The results indicated that the incorporation of PKS reduced the density of concrete, confirming its potential for lightweight applications. Workability and compressive strength decreased with increasing PKS content due to the high water absorption and lower strength of PKS compared to granite. However, concrete containing up to 20% PKS achieved compressive strength values close to the target strength for Grade 20 concrete at 28 days. It was concluded that palm kernel shell can be used as a partial replacement for granite up to an optimum level of 20%, offering a cost-effective and environmentally friendly alternative for sutainable concrete production