A rationalized a.c. impedence model for microstructural characterization of hydrating cement systems

An electrical conductivity model for hydrating portland cement systems has been developed. The high frequency a.c. impedance technique for characterizing the microstructure of cement paste and the hydration process of cement has been rationalized quantitatively for the first time. It is suggested that the major contribution to the a.c. impedance behavior of hydrating cement systems results from solid-liquid interfaces. All observed experimental phenomena can be explained by the proposed model. It is suggested that a.c. impedance techniques can be used for investigation of solid-liquid interfacial interaction in a porous material.