System behaviour in prestressed concrete T-beam bridges

About 70 prestressed concrete T-beam bridges, constructed in the Netherlands between 1953–1977, are still in use today with many located in the main highway network. This type of bridge consists of prefabricated and prestressed T-shaped beams, with an integrated deck slab, cross-beams and transverse prestressing. Even if these bridges are well maintained, two important factors demand the current need for assessment: (1) increased traffic loading and (2) potential lack of shear resistance. Using traditional assessment methods it was concluded that about 50% of these bridges do not fulfil the current design code requirements. However, this does not automatically imply that these bridges are structurally unsafe, since some potentially significant additional load-transfer mechanisms are not taken into account in a traditional assessment. This is strengthened by the observation that, in general, these bridges do not show any signs of distress....