Nachträgliche Durchstanzertüchtigung mittels Betonschrauben

Abstract

Stichworte Durchstanzen; Verstärkung; Betonschrauben; Simulation; Bemessungsansatz; PlattenbrückenPost-strengthening with concrete screws -Numerical investigations and comparison with a design approach's results A strengthening system using concrete screws as a post-installed punching reinforcement was developed at the University of Innsbruck. The system leads to a significant increase in the punching resistance. Compared to the demands of current standards especially the support regions of existing bridges and slabs often show a lack of punching shear resistance. The effectiveness and efficiency of the new strengthening system were investigated in four series of laboratory tests. The tests showed that the installation of the system leads to a significant increase of the punching resistance. This contribution deals with the development of a numerical model that can predict the punching loads of screw-strengthened plates. The modelling of the laboratory tests shows that this model is able to predict the punching load of unstrengthened plates as well as of screwstrengthened plates in an appropriate way. The punching loads from the laboratory tests and the simulations are compared to the predictions of a design approach. This approach allows to take the screws influence on the punching resistance into account of calculations. The recalculations of the tests show that the design approach predicts the punching resistances on the safe side.