Approach for the determination of the shear strength of existing post-tensioned bridge girders with a minimum amount of transverse reinforcement

摘要

Within the assessment of the load carrying capacity of old existing post-tensioned bridge structures with a low amount of transverse reinforcement it turns out, that the required shear strength according to current standards can often not be fulfilled. Shear tests show, however, that the present calculation models give conservative results for this type of structures. Therefore refined approaches, which consider this additional load capacity, are called for. The proposed model should be able to fulfill this task. For this purpose, a concept is reconsidered, which divides the analysis in various areas depending on the crack formation. Due to the fact that the shear carrying behavior is completely different in each section, the formulation of particular shear models corresponding to the actual behavior is needed. A comparison of the critical flexural shear crack model (FSC-model) with test results out of literature showed a good agreement. The structural reanalysis of an existing post-tensioned concrete bridge with a low amount of transverse reinforcement could demonstrate the potential of the developed approach.