Influence of Concrete Moisture Condition on Half-Cell Potential Measurement

The detection of on-going corrosion is one of the main issues during inspection of reinforced concrete structures. The half-cell potential measurement method is the most common and established non-destructive technique to support this task. But a lot of infrastructures are exposed to rain or seawater, which can cause heterogeneous moisture condition within one component. In turn, this can have influence on the potential mapping results, and as a consequence, the interpretability of the half-cell potential measurement is impaired. This paper focuses on the influence of concrete moisture condition on half-cell potential measurement. Laboratory and practical tests' results are analyzed qualitatively with varying moisture conditions due to natural exposure as well as with different prewetting conditions. On the basis of these results, recommendations are made how to evaluate half-cell potential mapping results. If large structures are inspected by half-cell potential measurements, it is advantageous to compare only these parts, which are in a comparable moisture condition by subdivision of the structure.