Analysis on Electrochemical Impedance Spectroscopy of the Hydration Process of Cement-based Materials with a Large Amount of Mineral Admixture

Abstract

High-performance concrete with a large amount of mineral admixtures is more and more preferred by research scholars. The pozzolanic activity and chemical constituents of mineral admixture directly affect the secondary hydration reaction time, and ordinary microscopic test means cannot reflect the continuity of chemical reaction process. In this paper, slag, fly ash and silica fume were used as mineral admixture to explore the electrochemical impedance spectroscopy change of mixing amount and curing age of a large amount of mineral admixture on the hydration process of cement-based materials, and the influence of mineral admixture ratio on electrochemical impedance spectroscopy was studied, the research results showed that the secondary hydration reaction of fly ash mainly occurs at the age of 42d-60d, while the secondary hydration reaction of slag mainly occurs at the age of 21-42d. The micro-aggregate effect of fly ash plays a role in increasing the electrochemical impedance of the cement slurry from the early stage of mixing, while the slag increases the electrochemical impedance of cement slurry due to the secondary hydration reaction. This paper continuously tested the hydration process of fly ash, slag and silica fume on cement-based materials.