DURABILITY AND MECHANICAL PROPERTIES OF CONCRETE WITH GASHUA LATERITE AS PARTIAL FINE AGGREGATE REPLACEMENT UNDER SULPHATE EXPOSURE

Abstract

The need for sustainable alternatives in the manufacturing of concrete has been fueled by the lack of natural river sand, its increasing cost, and the environmental damage caused by its uncontrolled extraction. Laterite soil, which is plentiful in tropical areas such as Nigeria, provides an affordable and environmentally beneficial alternative to river sand. This study examines the performance of laterized concrete produced with laterite soil from Gashua as partial replacement for fine aggregate at 0%, 10%, 20%, and 30% levels. Concrete samples were tested for workability, density, compressive strength, and resistance to magnesium sulphate (MgSO₄) attack after curing for 7, 14, and 28 days. The laterite soil was found to possess a specific gravity of 3.11 and a bulk density of 1791 kg/m³, indicating favorable load bearing capacity compared with conventional aggregates. Workability decreased consistently with higher laterite content. t 20% replacement, the mix recorded improved compressive strength and density, reaching 31.49 N/mm² and 2365 kg/m³, respectively compared to the control mix (30.01 N/mm², 2331 kg/m³). Laterized mixtures, especially at 20%, maintained greater strength (32.90 N/mm²) with MgSO₄ exposure than the control (23.37 N/mm²), indicating improved sulfate resistance. In conclusion, the results confirm that a reasonable amount of laterite (10–20%) improves sulfate durability and mechanical strength without sacrificing density, making laterite soil a practical, sustainable, and locally accessible substitute for river sand in the manufacturing of concrete.