CORROSION MONITORING OF STEEL IN CONCRETE - THEORY AND PRACTICE. CORROSION OF REINFORCEMENT IN CONCRETE. PAPERS PRESENTED AT THE THIRD INTERNATIONAL SYMPOSIUM ON "CORROSION OF REINFORCEMENT IN CONCRETE CONSTRUCTION", BELFRY HOTEL, WISHAW, WARWICKSHIRE, MAY 21-24, 1990

Maintenance and planning of the restoration work on reinforced concrete structures need a rapid, non-destructive inspection technique that detects corrosion at an early stage. In this paper the results of potential surveys on several bridge decks of the Swiss highways, realized with a new computer controlled eight-wheel measurement system, are presented. It is clearly shown that a fixed potential value (as proposed in ASTM C 876-80) for the identification and location of active corrosion of steel in concrete does not exist. A very rapid new technique using galvanostatic pulse measurements was tested successfully on site. It gives clear, unambiguous results on the corrosion state of the rebars when half-cell potentials are uncertain. In addition, the concrete resistivity and the corrosion rate of the rebars may be estimated simultaneously.(A) (This paper was also published in volume 3 of UK corrosion '88.... under the title Potential mapping of Steel in Concrete. See IRRD 827578). For the covering abstract of the conference see IRRD 831449.