Eco-friendly geopolymer bricks synthesized from alkali-activated sugarcane bagasse ash and rice husk ash

Abstract

The experimental research conducted involved the use of industrial crop residues as raw materials, specifically rice husk ash (RH) and sugarcane bagasse ash (SB) aimed at examining potential applications in sustainable building materials. Some of the crucial properties recognized are porosity, resistance to acids, water absorption at normal and high temperatures, bulk density, and compressive strength. Since the alumina content of RH is very less it was essential to replace it with SB in order to balance it with aluminates. Specimens of geopolymer brick were prepared with different concentrations of NaOH and cured for 7, 28, and 90 days. The highest strength in compression was found at a concentration of 16 M NaOH. The casted specimens then went into testing and characterizing various Si/Al ratios. It has been known that alumina has a positive effect on the grain boundary; however, it reduces the compressive strength. Specimens with a Si/Al ratio of 2:1 showed higher compressive strength after 90 curing days compared with the samples that had ratios of 3:1 and 1:1. These crop-based geopolymer bricks, using crop-derived ash materials, comply with ASTM C62 and Egyptian standards. These might be excellent sustainable industrial alternatives in the construction materials, aligning to SDG 9 and 11, industry, innovation, infrastructure, and climate action. This study promotes the eco-friendly industrial applications of agricultural byproducts, leading to innovation and contributing to climate action by reducing cement consumption.