Influence of transversal cracking on the shear load bearing behavior of composite dowels in slender concrete chords

Composite dowels are efficient, innovative shear connectors for use in engineering structures such as prefabricated composite bridges. Due to their ease of production in steel profiles with single-flange, their good load bearing and deformation properties and their applicability in slender concrete chords, composite dowels are increasingly being used in building construction. This paper describes push-out tests on puzzle-shaped composite dowels for slender concrete chords with a thickness of only 10 cm. Besides different variants of reinforcement, in particular the influence of different longitudinal stress states and transverse cracking in the concrete slab has been explored. For this purpose an appropriate test setup has been developed. In previous approaches for the static shear strength of composite dowels, the influence of transverse cracking is neglected. However, the presented experiments with slender concrete chords show a significant effect of concrete cracking on the composite dowels' shear carrying capacity. The presented experiments were simulated and analyzed by a three-dimensional, non-linear finite element model of the push-out tests.