Electrochemical techniques for corrosion assessment

This paper reviews the results of ?ve
di?erent electrochemical techniques
which have been investigated for use in
evaluating corrosion rates of steel re-
inforcement in concrete structures. Linear
polarization resistance, harmonic analy-
sis, AC impedance and galvanostatic pulse
transient analysis are all techniques which
were found to give consistent rates of
corrosion. Electrochemical-noise measure-
ments were found to be less suitable for
this application. Electrical equivalent-
circuit models are derived for corroding
and passive steel bars in concrete, and
these are used to interpret and understand
the results obtained from each technique.
The practical use of each technique is
discussed, and optimum measurement
parameters for practical application have
been derived from the experimental
studies.