Effect of Various Additives on the Properties of Fly Ash Based Geopolymer Mortar

In the present study, setting time and variation in strength of fly ash based geopolymer mortar prepared from natural sand as fine aggregates. Blast furnace slag (GGBS), micro silica and lime dust used as additives to fly ash based geopolymer mortar at 5, 10 and 15% of weight of fly ash. Alkaline activator used in the present study is combination of sodium silicate solution and sodium hydroxide solution. Concentration of sodium hydroxide solution was maintained 10 M and sodium silicate to sodium hydroxide ratio was fixed as 2.5:1 by weight. From the test results, it is observed that setting time and compressive strength geopolymer samples were significantly influenced by the type of additive added in the preparation of the geopolymer mortar.