Electrical Resistivity of Cement Pastes Undergoing Cyclic Freeze-Thaw Action

This study presents the electrical resistivity responses of saturated cement pastes undergoing cyclic freeze-thaw (F-T) action. An ordinary cement paste (OPC) and a blended paste (CS) containing ground granulated blast-furnace slag were used for the tests, and both pastes had water to binder ratios of 0.5. As the temperature decreases, the electrical resistivity increases. With increasing number of F-T cycles, the maximum electrical resistivity ${\rho }_{\max }$ increases, revealing progressive frost damage. The pronounced frost damage has also been evidenced by the loss of compressive strength and the appearance of visible cracks for both OPC and CS samples. During freezing, discontinuities arise in the electrical resistivity versus temperature curves for both OPC and CS samples, implying the occurrence of ice nucleation. Moreover, the ice nucleation temperature ${\theta }_{\mathrm{INT}}$ increases with F-T cycle number for all samples. The logarithm of electrical resistivity is a linear function of temperature after ice nucleation: $\log (\rho )=P\theta +A$. Both $P$ and $A$ increase linearly with F-T cycle number. The strong correlations between ${\rho }_{\max }$ and ${\theta }_{\mathrm{INT}}$, $P$ and $A$ provide evidence that these parameters could be capable to assess F-T damage of cement pastes.