Sustainable Development and Performance Assessment of Clay-Based Geopolymer Bricks Incorporating Fly Ash and Sugarcane Bagasse Ash

Abstract

Emission of carbon dioxide (CO2) either from the firing of clay bricks or from cement production, contributes considerably toward global warming. Conversely, the production of bricks is inevitable since a large number of bricks are needed to fulfill the housing sector demand. In this study, silty clay-based geopolymer bricks were produced incorporating fly ash and sugarcane bagasse ash. This was accomplished in two stages: the laboratory phase that comprised of production of cylindrical specimens, and the industrial phase whereby full-size bricks were produced based on the results obtained in the laboratory phase. The silty clay-based geopolymer bricks were developed with lesser energy input, i.e., forming pressure of 7 MPa with curing at ambient temperature. The whole set of mechanical and durability properties of the newly developed geopolymer brick yielded satisfactory results conforming to the standard codes. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results revealed the coexistence of sodium aluminosilicate gel (N─ A─ S─ H) and calcium aluminosilicate hydrate (C─ A─ S─ H), which led to a dense microstructure resulting in increased mechanical strength and ensuring enhanced durability of the brick structure. The environmental impact assessment confirmed the ecofriendly utilization of sugarcane bagasse ash in combination with fly ash in clay-based geopolymer bricks. The newly developed geopolymer can have a broad range of applications, including wall panel making, jet grouting, deep mixing, mortar for masonry constructions, canal lining, and grouting material used in backfill grouting during shield tunneling.