On the relationship between porosity and electrical resistivity in cementitious systems

The applicability of porosity-electrical resistivity relationships for hardened cementitious systems is addressed. The following equation ln F = ln mu + m . ln epsilon = ln (tau(2)/delta) + m . ln epsilon relating the electrical resistivity formation factor (F) to the porosity (epsilon), tortuosity (tau) and constrictivity (delta) was tested for Portland cement pastes hydrated up to 29 years and mortar hydrated for 28 days. Results for the well-hydrated pastes and, to a lesser degree, 28 day hydrated mortars followed the relationship.