Chloride-Induced Corrosion in Insufficiently Grouted Posttensioned Concrete Beams

Abstract

An experimental program was carried out to clarify the effect of chloride-induced corrosion on posttensioned concrete (PC) beams under different grout conditions using the electrically accelerated corrosion testing method. A series of accelerated corrosion tests were performed to evaluate the influence of insufficient grout condition on corrosion of sheath and prestressing tendon. The radial pressure surrounding the sheath during the corrosion process was also investigated. After a period of accelerated corrosion, the mechanical behavior of the deteriorated PC beams was clarified through loading tests. Prestressing tendon corrosion and its correlation with beam load-carrying capacity was also investigated. The results of the experiments demonstrate a significant influence of corrosion of sheath and prestressing tendon on load-carrying capacity of PC beams. The width of the corrosion crack in PC beams increases with grout filling level inside the sheath. The presence of water inside the sheath leads to increased rates of corrosion of the sheath and prestressing tendon, resulting in an earlier deterioration in the load-carrying capacity of PC beams.