Early hydration of calcium sulfoaluminate cement in the presence of hydroxyethyl methyl cellulose

Abstract

The influence of hydroxyethyl methyl cellulose (HEMC) on the early hydration evolution of calcium sulfoaluminate (CSA) cement within 72 h was studied by using isothermal calorimetry, thermal analysis (TG–DTA), X-ray diffraction analysis, and environmental scanning electron microscopy. The results reveal that the HEMC definitely has different influences on the hydration heat flow of CSA cement during different periods, postpones the occurrence time of two main heat flow peaks, and decreases the early hydration degree. HEMC assumes different influences on the formation and morphology evolution of hydrates with hydration proceeding. HEMC manifests great retardation on the formation of AFt and AH3 within 12 h of hydration, whereas ensures higher AFt content and lower contents of AH3 and AFm in cement paste after 24 h. Moreover, the influence of HEMC on the early hydration evolution of CSA cement enhances with its dosage increasing.