Comprehensive utilization of brick waste as a precursor in synthesizing geopolymer for treating black cotton soil

Abstract

ABSTRACT Black-cotton soil (BCS) exhibit swelling and shrinkage with fluctuations in moisture that affect various geotechnical constructions. Although lime and cement are extensively used for treating BCS, these are energy-intensive and emits-CO2. Geopolymer produced from industrial-wastes as precursor were found as alternative to these stabilizers, as it gives high strength, consumes low-energy, and emits low-CO2. Brick generate huge waste during construction and demolition. Although brick-waste was earlier used for geopolymer synthesis in structural-concrete, no study is dedicated for developing geopolymer from severely-weathered bricks (age > 60 years) i.e. used for stabilizing BCS. Furthermore, the existing studies were limited to curing of 3–7 days. In this study, the weathered-brick based geopolymer was developed using 8–12 M sodium-hydroxide (NaOH) alkali-activator. The BCS treated with geopolymer at 5–20% proportions of brick with activator-to-binder ratio (A/B) of 0.2, 0.35, and 0.5 were tested for unconfined-compressive strength (UCS) under varying curing periods (7 and 28 days). The maximum UCS was obtained at 10 M NaOH with an A/B of 0.35, and it is about three times that of raw BCS, thus paving way for alternate construction material.