THE HALF-CELL POTENTIAL METHOD OF LOCATING CORRODING REINFORCEMENT IN CONCRETE STRUCTURES

Corrosion of reinforcing steel is encountered in a variety of reinforced concrete structures. Corrosion can result in spalling of the concrete and a reduction in the cross section of the reinforcement, thus it is important to detect corrosion at an early stage of its development. The half cell potential technique can be used to locate corroding reinforcement without disrupting the concrete cover to the reinforcing steel. This guide presents a procedure for carrying out the half cell potential technique, describes the equipment required and explains how to interpret the results. An introduction to the electrochemical principles that describe the corrosion process of steel in concrete is provided. An appreciation of these principles is a necessary requirement for interpreting the results of a half cell potential survey. A glossary of electrochemical terms is included. (Author/TRRL)