The applicability of the Wenner method for resistivity measurement of concrete in atmospheric conditions

The Wenner probe method is an established, non-destructive method for the measurement of concrete resistivity. When testing is carried out for concrete in atmospheric conditions, electrode contact resistance is a major factor which can result in a measurement error, greatly influencing the accuracy and replicability of resistivity measurements. To achieve sufficient electrolytic contact between the Wenner Probe and concrete, surface wetting is commonly used. This is problematic as concrete resistivity is sensitive to changes in moisture content, resulting in variations in resistivity measurements. No resistivity testing Standards have been developed to achieve sufficient electrode contact without water saturation. This paper presents an innovative and practical method utilising existing Wenner Probe equipment, capable of eliminating and/or minimising the influence of these factors in atmospheric conditions. The new method minimises the impact of concrete surface variability by establishing an alternative, reliable electrolytic contact between the Wenner equipment probes and concrete.