Characterisation of Laterite Soil as a Partial Replacement for Fine Aggregate in Concrete Production in Ekiti State

This study characterises the physical, chemical, and mechanical properties of laterite soil sourced from Ekiti State, South West Nigeria, with a view to evaluating its suitability as a partial replacement for fine aggregate in concrete production. The increasing cost of conventional fine aggregates and the widespread availability of laterite deposits across Nigerian soil formations have prompted renewed interest in laterite-based concrete composites. The study employs a laboratory experimental methodology in which laterite soil is substituted for river sand at replacement levels of 0, 10, 20, 30, and 40 percent by weight of fine aggregate. Specimens are produced, cured, and tested for compressive strength, workability, water absorption, and flexural strength at 7, 14, and 28 days in accordance with relevant BS and ASTM standards. Chemical composition of the laterite is determined through X-ray fluorescence analysis. Findings reveal that compressive strength decreases progressively with increasing laterite content, with the 10 percent replacement level achieving 93 percent of the control mix strength at 28 days. Water absorption increases beyond 20 percent replacement, indicating porosity concerns at higher substitution levels. The study concludes that laterite can serve as a viable partial replacement at up to 10 percent without significant compromise of structural integrity. Recommendations include the exploration of cement supplementation to compensate for strength reduction at higher substitution levels. Keywords: laterite, fine aggregate, concrete, compressive strength, Ekiti State.