Phase composition of high strength binding material based on fine microspherical highcalcium fly ash material based on fine microspherical highcalcium fly ash

Abstract

The combination of factors was established for using high-calcium fly ash (HCFA) as a binder material of high early and long-term strength: (1) high dispersity of microspherical HCFA, 90% <10μm; (2) the positive effect of polycarboxylate superplasticizer, that allowed to use water / binder=0.25; (3) formation of finely mixed hydrate phases such as portlandite, ettringite, calcium carboaluminate hydrates and cryptocrystalline calcium hydrosilicates. X-ray powder diffraction quantitative phase analysis of initial HCFA and hydration products in high-strength specimens was performed, which contributes to understanding phase transformations of HCFA during hydration and to improving the properties of the binder.