Corrosion rate monitoring in the laboratory and on-site

The loss of metal per unit of surface and time defines the metallic corrosion rate. A review is made of the different electrochemnical methods used for measuring this parameter. Thus, polarization curves, polarization resistance transient techniques and electrochemical impedance are commented on. Some semiquantitative methods such as the measurement of the corrosion potential, concrete resistivity or galvanic current are also discussed. Concerning the application of electrochemical techniques for measuring corrosion rates on-site, the paper reviews some of the methods published in the literature with special attention to the sensorized confinement of the current. Finally, the values of corrosion rate measured in concrete specimens in the laboratory and on-site are given and levels of risk regarding loss in rebar cross-section are suggested. Copyright (C) 1996 Elsevier Science Ltd.