Performance Evaluation of Sustainable Eco-Bricks Incorporating Cement– Ground Granulated Blast Furnace Slag (GGBS) Binder with Sawdust and Rice Husk Ash as Partial Replacement for Fine Aggregate

Abstract

Abstract Rapid depletion of river sand due to increasing construction activities and the growing generation of agricultural and industrial waste have raised serious environmental concerns. This study investigates the use of sawdust and rice husk ash (RHA) as partial sand replacements in eco-bricks, focusing on their mechanical, durability, and thermal performance while promoting sustainable waste utilization. Sand was replaced with sawdust and RHA at combined replacement levels of 0%, 10%, 15%, and 20% by weight. The eco-brick specimens were evaluated for compressive strength, water absorption, density, and thermal insulation. The results indicated that incorporating sawdust and RHA reduced brick density and enhanced thermal insulation, whereas higher replacement levels reduced compressive strength and increased water absorption. The 10–15% replacement range provided a favorable balance of strength, durability, and sustainability. The developed eco-bricks show potential for non-load-bearing and low-cost construction applications while supporting waste recycling, natural-resource conservation, and sustainable construction.