The Concrete Dowel – A resource efficient Shear Connector.

The concrete dowel is a new efficient shear connector for composite constructions. A composite girder based on concrete dowels consists of a welded T-type girder or a halved steel girder with slots in the web. The halved girder is a very cost effective version of the concrete dowel, because only one continuous oxygen-cut is needed to manufacture two beams. The composite is assembled by the steel strip which is embedded in the concrete slab. A verification procedure for the fatigue behaviour was needed, after a design concept for static loads was already elaborated, to expand the application range. The local concept was used for the research on the fatigue behaviour. The project led to a design procedure which allows a prediction of the achievable load cycles. The current research project pursues the research on fatigue behaviour. The knowledge of lifetime prediction is enlarged by a fracture mechanical approach. The fracture mechanic allows a definition of the stress intensity factor ∆Kth for the steel strip to avoid crack propagation.