Monitoring of corrosion of prestressing steel cables in prestressed concrete bridges

There are many instances wherein presetressing steel in prestressed concrete has suffered sever corrosion leading to premature deterioration of bridges. Till date no reliable non-destructive test is available to monitor the condition of prestressing steel encased in cement group and high strength concrete. Attempts have been made to monitor the corrosion of prestressing steel cables by measurement of electrical resistance of the cables using accessible cable ends as terminal points. In this paper, some typical results obtained on some coastal bridges are resented. The limitations of the method are also pointed out