Hydration Kinetics of a Low Carbon Cementitious Material Produced by Physico-Chemical Activation of High Calcium Fly Ash

Abstract

The hydration kinetics of a ternary system containing high lime fly ash activated with alkali sulphate rich fly ash has been studied. The effect of low intensive mechanical activation of fly ashes influencing the particle packing and water demand was undertaken. A ternary blend of fly ashes and silica fume was found to show improved bond strength between the binder paste and aggregate rather than the binder paste matrix with progressive hydration after 90 days. Analogous physico-chemical properties of the developed ternary blend with the control cement were revealed. Quick dissolution of K⁺, Na⁺ and SO₄^2- into the liquid phase as well as consumption of Ca²⁺ by silica fume in a high-pH environment were the predominant factors for producing a dense non-expansive hydration product by the ternary blend.