Electrochemical behaviour of concrete reinforcing steel under cathodic polarization: comparison of some test procedures

The objective of this experimental investigation was to compare several techniques for studying the electrochemical behaviour of steel which was in mortars or in Ca(OH)₂ solution, containing chloride, and under cathodic polarization. In addition to usual electrochemical techniques (potentio-dynamic curves, etc.), two other procedures were used. They make it possible to easily determine electrochemical parameters which describe the steel behaviour. The first technique deals with determining the apparent polarization resistance of steel at constant applied potential. The second procedure uses a swift current decrease when polarizing steel with a constant current. It makes it possible to determine a transfer resistance and a 'double-layer capacitance'. The results obtained show fair agreement between the test procedures.