Innovative shear connection with composite dowels – verification using push-out test

In recent years many research on composite beams with innovative shear transmission with composite dowels have been conducted and innovative composite constructions have been built. One of the common types of shear connection is the method of rolled girders encased in a concrete slab. The combination of such method and pcb (precast composite beam) technology is called pcb-W (precast composite beam – coupled in web) technology which has been developing since 2003 in Germany. The longitudinal shear force is transformed by composite dowels instead of headed studs. The standard push-out tests according to EC4 have been performed at the Brno University of Technology to verify the behavior of the composite connection. The bearing capacity of the concrete dowel is mainly affected by reinforcement area. The minimum or recommended area of the reinforcement is given by [7]. If greater bearing capacity of concrete dowel was required, it would be possible to employ more reinforcement bars or use reinforcement bars of greater parameter. However, we have to consider the armoring and mounting of the structure, which is more complicated the more reinforcement we use. For this reason, nine specimens were prepared for the standard push-out tests, 3 specimens with common concrete and recommended area of reinforcement, 3 specimens with fiber reinforced concrete and reduced area of reinforcement and 3 specimens with fiber reinforced concrete and no additional reinforcement. The reason of this research is to lower the area of reinforcement bars in composite dowels and make the process less laborious. Key-Words: Composite structures, push-out test, pcb-W technology, steel fiber reinforced concrete