ABSTRACT
After recent discovery of corrosion failure of tendons with deficient grout in a Florida bridge, other similar post-tensioned bridges in Florida have been inspected. Other bridges were found to have analogous deficient grout; however, the amount and level of severity of deficient grout varied significantly between bridges. The grout deficiencies appear to be mostly isolated, but instances of significant corrosion of tendon steel components were observed. The deficient grout was found to have high moisture content and enhanced sulfate concentrations. The available data to date was compiled and corrosion of steel post-tensioned components have been observed at sulfate-to-hydroxyl ratio greater than 0.1. The critical sulfate concetration in the corrosion mechanism of steel in well-hydrated grout has not been elucidated, but the deficient grout with high moisture content may be comparable to the role of free sulfates in alkaline solution.
