Reliable identification of corrosion in reinforced concrete structures

For realistic and accurate description of the corrosion progres s in reinforced concrete structures, the inspection results from detection of ongoing corrosion are of vital importance, in particular for the probabilistic service life prediction. The crucial factor of the combination of inspection data and probabilistic service life prediction is the knowledge about the accuracy of the measurement method itself. The aim of this paper is the analysis of the accuracy of potential mapping. Potential mapping is a widely used inspection method for detection of ongoing corrosion in reinforced concrete structures. With this method, potential differences of macro-cell corrosion elements are measured by applying a reference electrode on the concrete surface. The Probability of Detection (PoD) is a main descriptor of the accuracy of an inspection method. Commonly, a POD curve describes the rate of detecting a defect with given defect size s, PoD(s). In the case of potential mapping, the defect size is for example the anode area. To obtain a PoD curve for potential mapping, it is necessary to compare potential measurements of reinforced structures with the true corrosion condi tion state. The true corrosion condition state is only identifiable by replacement of concrete cover. In general, owners will not agree to open a whole structure for evaluating the accuracy of an inspection method. Therefore, in this research, an approach based on numerical models is pursued. It is expected that through the integration of the potential mapping data the condition of the structure and correspondingly the service life time can be predicted more accurately.      «

For realistic and accurate description of the corrosion progres s in reinforced concrete structures, the inspection results from detection of ongoing corrosion are of vital importance, in particular for the probabilistic service life prediction. The crucial factor of the combination of inspection data and probabilistic service life prediction is the knowledge about the accuracy of the measurement method itself. The aim of this paper is the analysis of the accuracy of potential mapping. Poten...     »