An analytical model for determining the relative electrical resistivity of cement paste and C–S–H gel

With a combination of effective medium and percolation theory, an analytical model was proposed to acquire the relative resistivity of cement paste and C–S–H. The overall electrical resistivity and volume fraction of conductive phase, as main input values, are continuously determined by using non-contact electrical resistivity device and CEMHYD3D numerical model, respectively. The results show that an increase of hydration degree shows an improvement with the relative resistivity of solids and a reduction in critical exponent of capillary pores. While the relative resistivity of C–S–H and its exponent present constant values of 121 and 1.8, independent of hydration degree. Finally, the calculated results are compared to the reported values by previous literatures that have a good agreement.