Experimental and Numerical Investigations on the Shear Capacity of Existing Prestressed Concrete Bridges

Systematic re-analyses of prestressed concrete bridges in Germany show, that only some 5% can fulfil all requirements given by current design standards whereas more than 60% of the bridges ex- hibit relevant or severe deficits. Hereby, the majority of the deficiencies are related to insufficient shear capacity. In order to more realistically assess the actual shear capacity, several research pro- jects have been launched comprising numerical and theoretical investigations as well as extensive experimental testing. The present paper will firstly illustrate typical deficiencies of existing con- crete bridges and will then discuss current research activities on the shear capacity. In doing so, experiments using an innovative laboratory setup will be described allowing a realistic testing of concrete beams at a reduced length utilizing the substructure technique. Finally, full-scale experi- ments on a prestressed 7-span continuous road bridge will be presented and discussed.