Comparative Analysis of the Compressive Strength of Concrete Made from Various Coarse Aggregates

Abstract

The compressive strength of concrete is a critical parameter that governs the safety and durability of reinforced concrete structures. In Nigeria, the frequent collapse of buildings has been largely attributed to the use of substandard construction materials, particularly poor quality concrete aggregates. This study presents a comparative analysis of the compressive strength of concrete produced with coarse aggregates obtained from different sources in Nigeria, with the aim of evaluating their suitability for structural applications. Concrete cubes were produced using a constant mix ratio of 1:2:4 (cement: fine aggregate: coarse aggregate), a water–cement ratio of 0.45, and identical cement type, aggregate size, and curing conditions. Three types of coarse aggregates were investigated: granite from Ishiagu quarry (Ebonyi State), limestone (granite) from Okigwe quarry, and local red lump sandstone from Okigwe, Imo State. A total of concrete cubes was cast and cured for 7, 14, 21, and 28 days, after which compressive strength tests were conducted in accordance with relevant British Standards. The results showed that compressive strength increased with curing age for all aggregate types. At 28 days, granite produced the highest average compressive strength of 36.30 N/mm², followed by limestone with 31.56 N/mm², while sandstone recorded the lowest value of 25.18 N/mm². The findings demonstrate that aggregate source significantly influences concrete strength. Granite was found to be the most suitable coarse aggregate for high-strength structural concrete, limestone a viable alternative, and sandstone unsuitable for applications requiring high characteristic strength. The study provides empirical evidence to guide material selection and promote safer, more durable concrete construction in Nigeria.