Sustainable Sandcrete Block Production Using Orange Peel Ash as Partial Cement Replacement

Abstract

This study explores the potential of Orange Peel Ash (OPA) as a sustainable pozzolanic material for the partial replacement of Ordinary Portland Cement (OPC) in Sandcrete block production. Driven by the need to reduce the environmental impact of cement manufacturing and promote agricultural waste reuse, the research assessed the influence of OPA on the physical and mechanical properties of Sandcrete blocks. Experimental investigations were conducted on Sandcrete specimens with OPC partially replaced by OPA at 0%, 5%, 10%, 15%, 20%, and 25% by weight. The characterization involved particle size distribution, oxide composition via X-ray fluorescence (XRF), and specific gravity determination in accordance with BS standards. Performance was evaluated based on density, water absorption, and compressive strength. Results showed that the fine aggregate was well-graded, and the OPA exhibited a specific gravity of 2.45 within the acceptable range for agro-waste ashes. The incorporation of OPA had a marginal effect on block density and water absorption, both remaining within the acceptable limits of NIS 87:2007. However, compressive strength decreased with increasing OPA content. The control specimen achieved 2.62 N/mm², while 10% OPA replacement retained a sufficient strength of 1.70 N/mm² for non-load-bearing applications. Beyond 15% replacement, strength dropped below viable thresholds. The findings support the viability of ≤10% OPA replacement as a cost-effective and eco-friendly alternative in Sandcrete block production for non-structural use. This study encourages further research on optimizing OPA reactivity through chemical or thermal activation to expand its application in sustainable construction.