ELECTROCHEMICAL MEASUREMENTS FOR THE EVALUATION OF THE CORROSION STATE OF BRIDGE DECKS REINFORCEMENT

摘要

The bridge decks of four viaducts located in Northern Italy, with different conditions of corrosion within the reinforcement, were at first examined by potential mapping without the removal of the bituminous pavement and the impermeable membrane. Besides that, other point potential measurements were carried out directly on the concrete surface and in the same places also the corrosion rates, using the guard-ring device, were measured. A very interesting correlation was found between the results of potential mapping and those of the point measurements made after the removal of the pavement, while in some cases there has not been a good accord between these results and the corrosion rate values. Moreover, the chloride profiles in the concrete cover and visual inspection after the removal of the concrete confirmed the correlation between the results of the electrochemical measurements and the corrosion state, even in the presence of a certain variability depending on the type of concrete. The potential readings were also examined statistically with satisfactory results.