Effect of Binder index on Compressive Strength of Geopolymer Concrete

Abstract

The objective of this article is to present and discuss the effect of Class F Fly ash (FA), Ground Granulated Blast Furnace Slag (GGBS) and molarity of alkaline activator on the Compressive strength of Geopolymer Concrete (GPC). Sodium Silicate (Na2SiO3) and sodium hydroxide (NaOH) solution with 8, 10 and 12 alkaline molar activators have been used. The proportions for Fly ash to GGBS used are 80:20, 70:30, 60:40, 50:50, 40:60, 30:70 and 20:80. Alkaline liquid content to Fly ash ratio is taken as 0.36 and fine aggregate to total aggregate ratio is taken as 32%. The ratio of sodium silicate solution to sodium hydroxide solution is kept as 2.5. Three identical specimens for each variation were cast and tested after 7 days and 28 days ambient curing. A Parameter called Binder Index is introduced to quantify the effect of Fly ash, GGBS and molarity on the Compressive strength of Geopolymer Concrete at ambient temperature