Sustainable utilization of rice husk ash in concrete: A dual role as pozzolanic and filler material

The sustainable utilization of agricultural by-products in concrete production is essential for reducing environmental impact and enhancing material efficiency. Rice Husk Ash (RHA), a by-product of rice milling, serves a dual role in concrete as both a pozzolanic and filler material. This study investigates the influence of RHA on concrete properties, focusing on its pozzolanic activity and filler effect. RHA was incorporated into concrete at 0%, 5%, 10%, 15%, 20%, and 25% of the cement weight without replacing the cement. After thorough mixing, workability was evaluated through a slump test, while compressive strength was assessed after 7 and 28 days of curing. The results revealed that RHA significantly increased water demand to maintain workability and reduced the unit weight of hardened concrete. However, at an optimal dosage of up to 5%, RHA enhanced compressive strength and modulus of elasticity due to its pozzolanic reaction and particle packing effect. Higher replacement levels negatively impacted strength performance, highlighting the need for a balanced approach in mix design. This study underscores the potential of RHA as a sustainable alternative in concrete, reducing agricultural waste while improving material performance. By leveraging its dual functionality, RHA contributes to environmentally friendly construction practices by incorporating it into concrete production.