Effect of nano-silica and GGBS on the strength properties of fly ash-based geopolymers

Abstract

In this study, the roles of reactive alumina and process variables such as sodium content and molarity on the alkaline activation of nano-silica and ground-granulated blast-furnace slag are explored. Reactive alumina content of fly ash is the key parameter that determines the maximum compressive strength achieved from the alkaline activation. This paper also investigated the role played by nano-silica in fly ash-based geopolymer binders. The principal source of aluminosilicate is low-calcium fly ash, which was slowly blended with blast furnace slag to accelerate curing at ambient temperature. Then, different rates of colloidal nano-silica were added to the total binder on the days 3, 7, and 28 of curing.