PERFORMANCE EVALUATION OF DIKANUT SHELL AS PARTIAL REPLACEMENT FOR COARSE AGGREGATE IN CONCRETE MIX

This reports the investigation carried out into the performance of Dikanut shell (Irvingia gabonensis) as a partial replacement for coarse aggregate in lightweight concrete. The research was motivated by the environmental burden of agricultural waste and the rising cost of conventional construction materials. Experimental work involved replacing coarse aggregate with Dikanut shells at varying proportions of 5%, 10%, 15%, 20%, and 100% For a mix ratio 1:2:4, while maintaining a control mix of 0%. Tests conducted included compressive strength, slump, water absorption, aggregate impact value, and sieve analysis, in accordance with relevant British Standards. Results revealed that partial replacement up to 10% produced compressive strengths close to that of the control mix, with acceptable workability and durability characteristics, though higher replacement levels led to significant strength reduction At replacement levels of 5% and 10%, the compressive strength of the concrete remained within acceptable limits for lightweight applications, showing minimal deviation from the control mix, At higher replacement levels (15% and above), compressive strength dropped significantly, limiting structural applicability but highlighting potential for non-load-bearing uses. Water absorption increased with higher Dikanut shell content, reflecting its porous and fibrous nature Water absorption increased with increasing Dikanut shell proportions, a reflection of the shell’s porous and fibrous texture. The study concludes that Dikanut shell can serve as a cost-effective, locally available, and environmentally sustainable substitute for coarse aggregate in non-load- bearing and lightweight concrete applications. This work contributes to sustainable construction practices by valorizing agricultural waste, reducing dependence on natural aggregates, and promoting the use of locally sourced materials in civil engineering.