Corrosion propagation: comparison of electrochemical and mass loss measurements

The proper evaluation of rebars corrosion rate in concrete can provide reliable data for the evaluation and modeling of the service life and structural behaviour. In this work, experimental tests collected in researches related to chloride induced corrosion are presented. Corrosion rate monitoring was carried out by means of linear polarization resistance (LPR), while at the end of the exposure residual cross section (thickness loss) and maximum localised corrosion were determined. Average values of corro-sion rate in case of chlorides added to the mix were in the range 10-20 μm/year, while the localised corrosion rate was in the range 200-500 μm/year. The ratio between general and localised corrosion rate is in the range 10-40, similar to values found in literature. The presence of corrosion inhibitors and concrete coatings decreased general and localised corrosion rate.