Effect of silica fume and recycled concrete aggregate on the mechanical properties of GGBS based geopolymer concrete. (2022) - Premkumar, R.
Abstract: Global industrial waste and the exploitation of limestone for cement production create a massive problem. The rapid growth of the infrastructure sector worldwide has resulted in an enormous amount of construction and demolition waste, a primary environmental concern for the next decade. Potentially, by activating the cementitious properties with industrial wastes such as fly ash, rice ash, and others, geopolymer concrete can replace traditional portland concrete. GPC's mechanical properties were examined experimentally by recycled concrete aggregate varying the amount of sodium silicate(S.S.) and sodium hydroxide (S.H.) ratio, as well as substituting GGBS with silica fume. This study tested various GPC mixes for compression, flexural, and tension at 7 and 28 days. By combining Na2 SiO3 and NaOH in appropriate ratios (i.e. 1.5 and 2.5) and replacing ground granulated blast furnace slag with silica fume, two mixed proportions can be prepared (20, 40, & 60 percent). In geopolymer concrete, the slump decreases as the proportion of silica fume increases, but specimens containing 20 and 40 percent silica fume performed better mechanically than those with a Na2 SiO3 /NaOH ratio of 2.5. Moreover, it increases geopolymer properties by increasing the Na2 SiO3 /NaOH ratio.