Study On Cement Hydration Process Of Concrete By Electrochemical Impedance Spectroscopy

Concrete is the most important construction material in the construction industry today. Its durability is the biggest challenge the concrete structure is facing. Usually, we more often use the macro approach of destroying the original specimen to test the basic characteristics of concrete, but the changes in concrete’s performance cannot be observed from the meso-structure of the material by this method.Therefore, this article used the electrochemical impedance spectroscopy to test the basic characteristics of the cement hydration process in concrete, and deepen understanding on cement hydration process of concrete. Now, Electrochemical impedance spectroscopy is a new experimental method, which regards the concrete as a porous medium and understands the meso-structure of concrete by measuring the electrolyte solution’s electrical properties of the concrete’s pore structure and capillary structure. The electrochemical impedance spectroscopy is a lossless and dynamic method to measure the meso-structure of the hardened concrete paste, which can sensitively reflect the meso-structure changes in the cement hydration process.By measuring the electrochemical impedance spectroscopy of cement hydration process in concrete and applying the software of Origin7.5and ZsimpWin to fit and analyze the measured data, the changes of the impedance parameters were attained which represented the characteristics of the microstructures of concrete. The contents of this article are as follows:(1) By studying the electrochemical impedance spectroscopy of the concrete’s cement hydration process, the influence of the water-cement ratio and hydration age on the electrochemical impedance spectroscopy and the change rules of the impedance parameters of the concrete’s meso-structure were obtained.(2) By researching on the electrochemical impedance spectroscopy of the cement hydration process of the concrete which is mixed with fly ash or slag, the influence of different quantity of fly ash and slag on the impedance parameters and the meso-structure parameters of the concrete were attained.(3) On the basis of the experiments done, we understood how the electrochemical impedance spectroscopy of concrete with different quantity of fly ash and slag change with the hydration age.