Evaluation of Sandcrete Blocks Produced from Recycled Concrete Waste and Cassava Peel Ash

Abstract

This study assesses the engineering properties of sandcrete blocks produced using recycled aggregate from concrete

waste as a partial substitute for natural river sand. Cassava peel ash blended with cement served as the binder. Cassava

peels were burned at 700°C to produce ash, which replaced 20% of the cement in the binder. Recycled fine aggregate

was sourced from crushed concrete waste at a demolition site. Six mixture proportions were prepared by replacing

natural river sand with recycled material at 0%, 20%, 40%, 60%, 80%, and 100%, while keeping all other components

unchanged. The sandcrete blocks were tested for compressive strength and water absorption at 7, 14, and 28 days of

curing. Results indicated that incorporating these waste materials enhanced sustainability with minimal reduction in

strength at optimal replacement levels. Mixtures containing 20% cassava peel ash and 20–40% recycled fine aggregate

achieved compressive strengths comparable to the control mix and complied with relevant standards. Although water

absorption increased with higher replacement levels, values remained within acceptable limits at moderate substitution

rates. Overall, the findings demonstrate that agricultural and construction wastes can be effectively utilized in

sustainable sandcrete block production.