Reinforcement of Existing r.c. Bridges Through Composite Intradox Steel Elements to Prevent Brittle Failure

The reinforcement of existing r.c. bridges is influenced by the possibility to minimize the period of closure of the road lane. The authors proposed a reinforcement method based on the increment of strength capacity of the existing beams with the introduction of new steel ones placed at the intrados between the r.c. beams. This generates a composite RC-steel structure able to reduce the main vulnerability elements and mostly brittle failure mechanisms. The coupling of a temporary steel bridge provides the separation between works and road traffic, also permitting the continuous use of the road lane, together with a low-cost amount of works. A simple numerical model quantifies the performance of the restored bridge, applying the method on a real case study.