Zur Einleitung von Vorspannkräften in dünnwandige Hohlkastenquerschnitte

Abstract

On the introduction of post-tensioning forces into thin-walled box girder cross-sections. In the course of a research project currently being conducted at the Institute for Structural Engineering at the TU Wien, box girder cross-sections consisting of thin-walled semi-precast concrete elements are being investigated for their use in bridge construction. The box girder cross-sections are assembled segment by segment on the construction site and tensioned together with external post-tensioning to form a self-supporting bridge girder. Subsequently, the web, floor and deck slabs are completed with in-situ concrete, thus producing a monolithic structure without joints. The post-tensioning of the thin-walled box girder cross-section poses a particular challenge. In this paper, a new approach to the introduction of post-tensioning forces in thin-walled box-girder cross-sections is presented, based on experimental investigations carried out and their analysis with a nonlinear FE calculation. Two different manufacturing methods of the blisters were investigated, on the one hand a prefabricated construction method and on the other hand a cast-in-place method. It has been shown that the production of blisters as precast elements is preferable for the introduction of post-tensioning forces into thin-walled box girder cross-sections due to the shear joint created by the in-situ concrete construction method.