In spite of much research invested in the study of concrete reinforcement corrosion induced by chlorides, there is still no agreement on an accurate method for determining the chloride threshold value initiating corrosion. The objective of this work is to present a new test set-up that considers the localized character of corrosion initiated by chlorides. This approach is based on a physical separation between the anode, contaminated with chlorides, and the cathode, which is chloride free. This approach will allow to quantify the galvanic corrosion current, making it possible to determine, in a second step, the chloride threshold values for corrosion initiation. The criteria for corrosion initiation was a threshold corrosion current defined as a current that is independent of the cathode/anode surface ratio. It was then important to test the influence of the geometric surface ratio on the galvanic corrosion current. It was found that it is an important parameter that needs to be taken into account when studying corrosion in the presence of chlorides. Preliminary results of threshold values were determined based on this criterion for CEMI and for several types of steel surface conditions. The preliminary results also give an idea of the influence of chloride contents on the galvanic corrosion currents.