OPTIMIZATION OF CONCRETE MIX DESIGNS USING LOCALLY SOURCED AGGREGATES IN ANAMBRA STATE: A FRAMEWORK FOR SAFE AND COST-EFFECTIVE CONSTRUCTION

Abstract

This study investigates the optimization of concrete mix designs using locally sourced aggregates from Anambra State, Nigeria, with the aim of developing a framework for safe, durable, and cost-effective construction. Considering that aggregates constitute a significant proportion of concrete and greatly influence its performance, the research evaluates the suitability of selected sedimentary rock aggregates obtained from Umunya, Nsugbe, Ogbunka, Nkwelle Ezunaka, and Aguleri. Concrete specimens were produced and tested for compressive strength at 7, 14, and 28 days to assess their structural performance. The results revealed variations in aggregate quality and concrete strength across the sampled locations. Although all concrete samples exhibited progressive strength development with curing age, the maximum 28-day compressive strength achieved was 15.90 N/mm² using aggregates from Ogbunka, while lower strengths were recorded for the other locations. These values fell below the minimum strength requirement for structural high-strength concrete as specified by relevant standards. However, the findings provide valuable insights into the performance limitations and potential applications of locally sourced aggregates in conventional concrete production. The study proposes a framework for optimizing concrete mix designs through careful aggregate selection, material characterization, and mix proportion adjustments to enhance performance while minimizing construction costs. The research contributes to sustainable construction practices by promoting the effective utilization of local materials and providing guidance for engineers, contractors, and policymakers in achieving safe and economical concrete construction in Anambra State and similar environments.