The effect of metakaolin on the hardening process of alkali activated slag by using electrochemical impedance spectroscopy

The purpose of this research work is to study the hardening behavior of the alkali activated slag-metakaolin (AASM) material from a new electrochemical perspective. The measurements of the compressive strength and the electrochemical impedance spectroscopy (EIS) were conducted. The results demonstrated that the strength of AASM paste decreases with the increase of metakaolin content. In addition, a suitable electrochemical equivalent model has been used in order to analyse of the relationship between the microstructure of the AASM paste and the EIS data. And found that the resistance of ion transport process Rct1 show an increasing trend over the testing period and the compressive strength and the Rct1 of AASM has similar growth trend and strong correlation, which means that the EIS may be used to predict the strength development of the AASM paste. (paper)