Field testing for Assessment of Corrosion in Reinforced Concrete Structures
Half Cell Potential Survey
Corrosion being an electrochemical phenomenon, the electrode potential of steel rebar with reference to a standard electrode undergoes changes depending on corrosion activity. A systematic survey on well defined grid points gives useful information on the presence or probability of corrosion activity. The gird points used for other measurements, namely, Rebound Hammer and UPV can be used for making the data more meaningful. The common standard electrode used for concrete is the Copper-Copper Sulphate Electrode. The measurement consists of giving an electrical connection to the rebar and observing the voltage difference between the rebar and a reference electrode in contact with concrete surface. A systematic “potential mapping survey” is considered to be more useful for on-site identification of the corrosion state of the rebars.
Copper-Copper Sulphate Electrode for potential measurement in rebar
Half-cell potential measurement on an actual structure
The measurement consists of giving an electrical connection to the rebar and observing the voltage difference between the rebar and a reference electrode in contact with concrete surface.
Half-cell potential measurement on a corroded structure