2022 Volume 76 Issue 1 Pages 138-144
The purpose of this study was to gain knowledge about the changes in electrical properties of mortar during the curing process. The type of cement and the mixing-water content were changed, and the impedance changes were measured in the time range of 0h to 96h. The Cole-Cole plots of normal portland cement was the characteristic of RC parallel circuit. For all mortars, the electrical resistivity decreased gradually from after placing until 3-4h and then increased rapidly. For a water-cement ratio of 0.5, the peak values of relative permittivity at low-frequency （＜5MHz） decreased in the order of high-early-strength, normal, and low heat portland cement. On the other hand, on the high-frequency side （≥20MHz）, the order was reversed. These changes were discussed in terms of the hydration reaction and the ionization of the cement components.
