On the measurement of the polarisation resistance of reinforcing steel with embedded sensors: A comparative study

On site measurement of durability parameters with permanent monitoring systems has been recognised as an important source of information for the development of reliable models to predict the lifetime of reinforced concrete structures. In this study, four electrochemical techniques were applied to determine the polarisation resistance (Rp) of steel embedded in mortar to select the best technique to be used in the development of embedded sensors for corrosion rate monitoring. It could be concluded that, if an adequate time scale to perform each measurement is used, all the techniques lead to the same Rp value within a known experimental error. However, the potentiostatic pulse technique presents some advantages to be used in the development of embedded sensors because it is fast, does not require sophisticated equipment or data analysis, and allows the simultaneous evaluation of the Rp and electrical resistance between the rebar and the reference electrode.