Durability Properties of Geopolymer Concrete Containing Ground-Granulated Blast Furnace Slag and Black Rice Husk Ash

Concrete production requires a large amount of Ordinary Portland Cement (OPC) which contributes to enormous carbondioxide emission leading to serious environmental problems. Geopolymer concrete (GPC) is one of the innovative solutions to overcome such environmental issues concerning OPC usage. It is produced by mixing mineral admixtures rich in silica and alumina with alkaline activators resulting in binders due to the polymerization reaction. In this study, GPC was produced using the mineral admixture ground-granulated blast furnace slag (GGBS) as a primary binder which was replaced with black rice husk ash (BRHA) in different proportions of 10, 20 and 30% by weight. A mixture of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) was used as the alkaline activators. After the application of oven curing, the specimens were exposed to acid and seawater resistance tests for 30, 60 and 90 days to evaluate the durability properties of geopolymer concrete. The experimental results showed that the addition of BRHA to geopolymer concrete specimens (GPR1 and GPR2) showed better resistance against acid and seawater as the weight and strength losses were lower for 10 and 20% replacement levels than the control specimens (GP).