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Novel approach for determining the electrical resistivity of reinforced concrete

The electrical resistivity of concrete correlates with different durability related parameters. Due to the heterogeneity of reinforced concrete a reliable determination of the concrete resistivity at a structure is a challenging objective. The application of a WENNER probe in the area of reinforcement bars or moisture gradients can lead to misinterpretations.
In order to counteract the influence of heterogeneities the Electrical Resistivity Tomography, developed in geophysics, is applied to determine the distribution of the electrical resistivity in concrete elements. The method is adapted to the demands of reinforced concrete structures. The studies focus on a comparison between the WENNER electrode configuration, already known in civil engineering, and the dipole-dipole electrode configuration and highlight the applicability for reinforced concrete elements. The results show that the method is applicable on reinforced concrete if the position of the reinforcement as well as boundary effects are considered within the evaluation.