Investigation of the capillary rise in cement-based materials by using electrical resistivity measurement

In order to explain the nonlinear relationship between uptake water and time(0.5) during early stage of capillary rise in cement-based materials (CBMs), a batch of well-designed specimens of cement mortar with nine embedded electrodes were introduced. Water distribution in specimens and process of capillary rise in CBMs were investigated by testing the electrical resistivity. Based on the results of experiments, an improved Terzaghi capillary rise model was established by considering the variation of saturation degree of CBMs above the wetting front. Results show that (1) the nonlinear relationship between uptake water and time(0.5) was caused by the increase of saturation degree in CBMs above the wetting front, which caused the decrease of capillary pressure, (2) there was an unsaturated transitional region between the wetting front and saturated region during the capillary rise, the height of this region increased with the rise of wetting front, (3) the improved Terzaghi capillary rise model fitted experimental data well. (C) 2018 Published by Elsevier Ltd.