Corrosion-induced damages and failures of posttensioned bridges: A literature review

Abstract

Corrosion of posttensioned bridges raises great concern, since the only way to safely assess the condition of the tendons is through destructive evaluation. In this scenario, this paper presents the results of an extensive literature review on reported cases of corrosion of posttensioned bridges and few prestressed structures. The aim is to increase knowledge about the structural consequences of possible corrosion-induced failure mechanisms. The cases were rated according to the increasing severity of the observed damage and consequent interventions as follows: ordinary maintenance is effective, extraordinary maintenance is necessary, and maintenance is insufficient or absent. It was found that most corrosion-sensitive structures were segmental and box section beam bridges. Most cases required extraordinary maintenance. Warning signs were often observed. The damage was mainly ascribed to design and execution mistakes that facilitated the ingress of external chlorides causing corrosion. The paper concludes with a discussion of the consequences for structural safety.