Evaluation of Performance of Grout Materials in Protection of Prestressing Steel

Prestressing cables are widely used in huge constructions like buildings and bridges. Corrosion of prestressing steel is more dangerous than the corrosion of reinforcing steel in concrete. Stress corrosion is propagated due to corrosion initiation in prestressing steel under stressed condition. Corrosion resistance of the prestressing steel depends upon the grout material. In this investigation three types of grout materials namely cement grout with non-shrinking admixture, polyurethane foam and epoxy grout were assessed for its suitability within the prestressing cable duct. The performance of grout materials to protect against prestressing steel corrosion was evaluated by different electrochemical techniques such as OCP measurements, anodic polarisation test and impressed voltage technique. The mechanical property of the different grout materials were test at room and elevated temperature. Among the three grouts, epoxy based grout system showed better corrosion resistance properties.