Title: Normalization of Temperature Effect on Concrete Resistivity by Method Using Arrhenius Law (with Appendix)

Author(s): Yanbo Liu and Francisco J. Presuel-Moreno

Publication: Materials Journal

Volume: 111

Issue: 4

Appears on pages(s): 433-442

Keywords: Arrhenius law; durability; electrical resistivity; temperature

DOI: 10.14359/51686725

Date: 7/1/2014

Abstract:
Electrical resistivity is increasingly being used as a nondestructive technique to evaluate the durability properties of concrete. While concrete resistivity is temperature dependent, the effect of temperature that may cause misleading results has thus far not been properly taken into account. In this paper, an extensive investigation was carried out to study the effect of temperature on the electrical resistivity of water-saturated and unsaturated concrete specimens. Resistivity measurements were performed at temperature cycles ranging from 10 to 45°C (50 to 113°F). The profiles of resistivity versus temperature were found to conform to the Arrhenius law. Furthermore, the activation energy (the amount of thermal energy required to promote a mole of the ions in the concrete pore solution to carry a current flow under an electric field) was found to be dependent on the resistivity of the concrete. Based on these findings, a methodology was developed to normalize the resistivity values measured at different temperatures to the values at a reference temperature (for example, 21°C [70°F]), and to predict the resistivity variations due to temperature changes. Compared with existing methods, the method proposed in this paper is more accurate for normalizing the temperature effect on concrete resistivity.