ABSTRACT
The ducts of a postensioned bridge have been grouted by accident with a paste contaminated by chlorides. As soon as the mistake was noticed, visual inspection of tendons and corrosion rate measurements were undertaken in order to delimitate the extension of the damage. As the corrosion resulted not important, the bridge was reinforced before opening to service and a monitoring was recommended in order to predict future performance.
The corrosion monitoring is made by using on-site linear polarisation measurements with a corrosion rate meter with a sensorized guard-ring. The results show that corrosion rate varies along the time. Statistical treatment of the corrosion rate values has enabled to calculate a corrosion rate which may be used for predicting a period time to failure of the tendons. As well, pit depths have been measured in order to relate localized attack to mean, or representative corrosion rate.
