Shear testing on a prestressed continuous concrete beam

The structural assessment of existing older prestressed concrete bridges on the basis of current standards often uncovers substantial deficits in terms of the required shear reinforcement in the main girders of bridge superstructures. However, shear failures of existing German bridge structures have not been reported so far. Until now, only few tests on prestressed continuous concrete beams have been carried out. In order to investigate the load bearing capacity of such beams more precisely, a large scale experiment was executed at TU Dortmund in the course of a research project funded by the Federal Highway Research Institute (BASt). Within this project a particular focus was put on the investigation of the additional shear load bearing capacity caused by the compressive arch effect. Therefore an extensive range of measurement devices was used in the experiment to guarantee the continuous recording of structural behavior and internal forces. In this contribution the large scale experiment as well as the main findings are presented. An interpretation of the test results based on current standards and a comparison with the compressive arch model are carried out.