Use of impedance spectroscopy to determine the displacement of water in cement paste under small loads

Abstract

The effect of mechanical loading in concrete structures may cause deformation by creeping. The physical origin of this phenomenon is not well known, but water seems to play an essential role in it. Impedance spectroscopy in the high frequency region can detect water movements towards empty pores, even when the applied load is small. In this paper a system for application of mechanical loading compatible with simultaneous impedance spectroscopy measurements is presented. The effect of several parameters (ageing, water to cement ratio, water content) on cement paste samples performance under mechanical loading is analysed through the corresponding impedance spectra.