Cathodic Protection of Steel Reinforcement in Concrete

Abstract

The present research has be investigated the relation between the inducedlevel of polarization and the area of the embedded steel, area of the anode, theconcrete resistance and the level of applied external voltage. During exposureperiod, the specimens were polarized using three different levels of externalvoltages (750, 1000, 1500) mV. Various electrochemical and electricalmeasurements were made, these include half cell potential, degree of polarization,flowing current and the actually applied voltage as compared with the external one.The results indicate differential moisture content in each specimen hasproduced different potentials along the steel bars. Greater polarization has alwaysbeen associated with the submerged portion of the specimen where the concreteresistance is at its minimum. whereas the degree of polarization is directlyproportional to the level of external voltage. The results also illustrate that, for agiven level of externally applied voltage, the degree of polarization is dependent onthe area of protected steel and the area of the anode. Thus the polarization increases with the decrease in the protected steel area and the increase of the areaof the anode.