Effects of fineness and chemical activators on the hydration and physical properties of high-volume fly-ash cement pastes

Abstract

The effects of the Blaine fineness of fly ash (FA) and chemical activators on the hydration and physical properties of high-volume fly-ash cement pastes were investigated. The initial hydration was assessed via isothermal calorimetry, and the hydrate composition was determined through X-ray diffraction and thermogravimetric analyses. With increasing Blaine fineness, hydration accelerated at early ages. The pozzolanic reaction of FA accelerated with age. The compressive strength increased with increasing Blaine fineness. The chemical activators increased the initial strength but decreased the long-term strength and accelerated Ca(OH)2 consumption. With increasing fineness, the Ca(OH)2 content of the pastes decreased.