Abstract

In-spite of the rise in the cost of river sand which has become quite challenging for low-income households to acquire, rapid increase in infrastructure projects in Nigeria has also led to indiscriminate mining of river sand. The adversely aggrandizement of river sand mining includes river bank erosion, river bed degradation, loss of biodiversity and deterioration of river water quality and ground water availability. Researchers have beamed their searchlight to find substitutes for river sand to be used as fine aggregate in concrete production to address these issues. One of the locally available resources is laterite. Laterite is an abundant soil material which is formed from topical or sub-tropical weathering. The tremendous increase led this study to investigate utilization of lateritic soil from a borrow pit within Ondo state, Nigeria. Area explored for the laterite was Ile-Oluji labelled (Lat. I) in replacement of river sand as fine aggregate and produced laterite-fine aggregate concrete. However, experiment were designed and conducted to study the performance of laterite as partial replacement for river sand to assess the durability performance of this concrete. A lateritic replacement levels of 0, 10, 20, and 30% were prepared in the form of cubes (150 × 150 × 150 mm). The selected laterite soil was subjected to laboratory tests to determine their physical, chemical and mineralogical contents and their results were obtained. The strength and durability assessment of Ile-Oluji lateritic concrete with their control concrete specimen were investigated through compressive strength, splitting tensile strength and sorptivity tests. After water curing for 28 days, the specimens were tested for the determination of compressive strength and durability against water absorption. It was found that concrete with low water absorption can be produced through the integration of 20% of lateritic sand. The result revealed that at 56 days of curing, concrete attained optimum compressive strengths of 11.45 N/mm², respectively for mixtures produced by partially replacing river sand with 10% Lat. I. The sorptivity was optimal at 5.66 ×10^-4 mm/min^0.5 with partial replacement of laterite at 10% Lat. I respectively. Thus, 10% Lat. I gives the optimum strength. The insight gained from this experimental research enables the development of optimized mix designs and predictive models for utilizing laterite as partial replacement for fine aggregate in concrete production.