The Role of Fly Ash in the Granulated Blast Furnace Slag-Based Geopolymer

Inorganic polymers using slag as cementitious materials have the advantage of a short setting time, high early strength, but the sensitivity of the reaction rate to temperature and the likelihood to subsequently crack, which leads to reduction of strength, limit its application. This article, by configuring different proportion of fly ash and slag, studied its dry shrinkage with the different kinds of activator, the effects of fly ash on the hydration heat release curves, differences of setting time and strength with different configuration, and then explored the effect of fly-ash in inorganic polymer. Experiments had shown that through rational configuration, the addition of fly ash can effectively reduce the rate of heat release and the amount of heat, meanwhile can solve the problem about short setting time of alkali-activated cementitious materials without reducing its strength.