AC impedance spectroscopy of cement - based materials: measurement and interpretation

Abstract

In this article, factors reflecting the sources of measurement errors of AC impedance spectroscopy (ACIS) of cement - based materials and the related ACIS data interpretation were reviewed. Associated with reduction measures and correction methods for measurement error of ACIS, reasonable measurement parameters and a simple and convenient measurement procedure for ACIS of cement - based materials were recommended to minimize the measurement errors. To account for the different responses of multi - scale unconnected pores, Maxwell model was found to be most appropriate for describing AC electrical response of cement - based materials. Inappropriate models and measurement error tend to increase the dispersion and frequency dependence of impedance parameters. Differential impedance analysis can be a potential method to perform parameter identification of ACIS. Additionally, averaging and mixing phenomena in the microstructure interpretation of dielectric properties and ACIS related with unsaturated sample, the multidimensional characterization should be as key considerations for ACIS of cement - based materials.