P 1097 – Development of an integrated floor slab system for steel and composite construction
The goal of this research project is to develop an integrated floor slab system in steel and composite construction ready for practical application in a demonstrator stage as well as the derivation of engineering models for the description of its structural behavior. The starting point of this research project is the floor slab system InaDeck which was conceived within the framework of the FOSTA research project P 879. This floor slab system is characterized by large spans and integrated building services. In order to lead this integrated floor slab to practical suitability on the one hand the floor slab elements need to be optimized with regard to their structural behavior, their economic efficiency and their resource utilization (rolled sections and shear connectors), on the other hand the integration of the slab system into the overall supporting structure of the building has to be developed.
The structural behaviour of the optimized floor slab elements is explored in experimental and theoretical investigations. First, the load-bearing and deformation behaviour of the shear connectors due to different stress combinations are investigated. The push-out tests with combined tension stress shown a decrease of the ultimate load by increasing tension.
A similar effect could be observed in the tests with cracked concrete. In shear tests with additional transverse bending a decrease of the ultimate load is occurred. However, this effect could not verified in the beam tests. In final beam tests, the local mechanisms in the area of web openings and the effects of a combined lateral and longitudinal bending stress in the slab element are investigated.
To this end, structural steel connections to columns (in or beyond the facade plane) and girders will be developed as well as detachable joints that allow for building recycling and take into account greater flexibility in the grid size of the building. Here, on the one hand the local mechanisms in the area of web openings are examined on the other hand the effects of a combined lateral and longitudinal bending stress in the slab element are tested.
In vibration tests on a 10.5 m steel composite floor beam, the vibration behaviour of the beam with increasing web openings is analysed. The results shown a positive effect of the eigenfrequency if the web openings are located near to the support. The damping of the slab was low throughout.
Based on the investigations carried out engineering models for the composite slab system are derived. The result of the research project is to provide an applicable and useful, integrated steel composite floor system for modular, wide spanning supporting structures.
Dipl.-Ing. M. Kopp, Prof. Dr.-Ing. M. Feldmann, Dr.-Ing. M. Claflen, Prof. Dr.-Ing. J. Hegger