Study On The Characterization Of Cementitious Materials Hydration Process

Currently the basic characteristics of cementitious materials are mostly tested by conventional macroscopic methods, but the method requires to damage the original specimen, and cannot detect the material properties from time to time in the microstructure, meanwhile waste a lot of manpower, material resources, and the test results do not always reflect the construction materials used on site performance. This paper proposes two novel electrochemical research methods, electrodeless resistivity meter method and electrochemical impedance spectroscopy method to study Portland cement and magnesium phosphate cement. They use non-contact technique, which prevents the influence on experimental result from contact resistance and contact capacitance, with high accuracy, automatic recording, test curve and obvious physical sense, etc., in order to better characterize the hydration characteristics of cementitious materials.(1)This paper explores the basic mechanical properties of Portland cement and magnesium phosphate cement' basic performance and a different mix proportion, external factors on the mechanical properties of cementitious cement in depth;(2) This paper study element of the ratio and cement admixtures, etc. on affecting the cementitious material on the hydration process of measurement procedures for the both cementitious materials by electrodeless resistivity meter and electrochemical impedance spectroscopy, and analysis of the different water-cement ratio of cement paste and admixtures on resistivity and the development of characteristic impedance spectroscopy curve of period;(3) This paper study the development of cement-based materials resistivity curve resistivity hydration mechanism and analysis differential curve of the first and second peaks reflected and expand the electrodeless resistivity meter application to the early age of cement, including the use of the method for the determination of cement setting time, quickly testing the strength of cementitious materials;(4) This paper proposed and demonstrated a new equivalent circuit model used in electrochemical impedance spectroscopy which is better than the classical equivalent circuit hydration process model and equivalent circuit model proposed by Gu et.al. of cementitious materials, research hydration process with the new equivalent circuit model electrochemical impedance spectroscopy curve, and analysis electrochemical impedance spectroscopy curve with different mix proportion and additives influencing on impedance parameters and identify the relationship between electrochemical impedance spectroscopy curve and cementitious material strength values.