Electrochemical Impendance Spectroscopy Characteristic Of Hydration Process For Cement-basic Materials

Cement-based materials and concrete is the most important modern building materials. Its strength and durability in all environments has an important influence on the quality and the life of the projects. In the past, using the macro-method tests the basic properties of cement-based materials, but the macro-approach requires the destruction of the original specimen, and can not proceed from the material to the microstructure of the material from time to time to monitor the performance of the materials.Either it takes a lot of manpower, material, or the testing results do not necessarily reflect the performance of the materials used in the construction site.Therefore, this issue presents the approach testing the basic characteristics of cement-based materials using of electrochemical impedance spectroscopy (EIS) approach. EIS is a new experimental technique. It treats the cement-based materials and concrete as a porous medium, in order to understand its microscopic structure through its pore and capillary structure and the electrical propertiesof the cement/aggregate interfacial transition zone of the electrolyte solution. It can often detect the material, observing the properties change of materials and structures over time; besides, the testing process does not destroy the sample, and is a non-destructive testing methods.Based the the existing Electrochemical Impedance Spectroscopy theory, the issue measures electrochemical impedance spectroscopy of cement-based materials, ordering, fitting and analysising the experimental data using Origin8.0 and Matlab6.5, getting variation of impedance parameters for the microstructure of cement-based materials.It confirmed that the method is the feasibility for the characteristics of cement-based materials. In this study, the contents and main results are as follows:(1) Through the experiment, studying the electrochemical impedance spectrosco- py the cement hydration process of change, getting the impact of EIS of the cement hydration process by hydration and water-cement ratio, and the changes of impedance parameters of the microstructure of cement paste.(2) Through the experiment, of the cement / fly ash / slag EIS Composite System, And mortar, concrete, electrochemical impedance spectroscopy, getting the impact of EIS of cement hydration process, by admixture, aggregate, sand mix on the activity .(3) The hydration stability of cement paste specimens soaks, dries, measures, and in no caseof a major change of the structure, as the water content decreases, the electrochemical impedance spectra and impedance parameters change.(4) As the base of the experiment, the structure parameters of penetrating is correspondence with the impedance parameters of micro-structure of the cement-based materials, getting the changes of the permeability structure of the cement-based materials in different conditions(cement paste, cement / fly ash / slag composites).