Potentiostatic transient technique, a simple approach to estimate the corrosion current density and Stern-Geary constant of reinforcing steel in concrete

The linear polarization resistance (LPR) method, introduced by Stern and Geary, is widely used in determining corrosion rates of steel bars in concrete or synthetic pore solution. The major limitation of this method is that the value of the Tafel slopes, and consequently the Stern-Geary constant (B), is necessary for accurate calculation of the corrosion rate. This paper proposes a simple method for determining the corrosion current density and the Stern-Geary constant, using the results of the potentiostatic transient technique. The effect of the Stern-Geary constant on the corrosion rate of steel bar in concrete is also discussed. Results of this study show that potentiostatic transient method can be used successfully to determine the corrosion rate of steel bars in concrete without using the pre-assumed value of B.