Degradation and Rehabilitation of Gerber Saddles of Concrete Bridges

In recent decades, many concrete bridges, built in the 60s and 70s of the 20th Century with a Gerber-girder scheme, show severe damage of the saddles due to concrete degradation and reinforcement corrosion. On the basis of the recent Ministerial Guidelines for the assessment of existing bridges, it is necessary to evaluate the state of the Gerber saddles in a large number of bridges on both main and secondary roads. To do this, it is necessary to apply flexible assessment procedures that can be adapted to several situations and that allow a speedy assessment of the intervention priorities. The methodologies of intervention represent the crucial point for a rapid rehabilitation of these infrastructures. In this paper, on the basis of some case-studies, assessment and strengthening methodologies are proposed that can be applied to different real cases, in consideration of the budget available, with the aim of drafting an operative list of priorities and improving as many bridges as possible, currently in service.