Abstract Static and instantaneous behaviour of connections between steel and concrete is investigated in the context of composite beam bridges with high strength concrete. Push-out tests were performed under a range of conditions and analysed by means of a 3D-FE model. Experimental results show that the average ultimate shear stress is about 5.5 MPa and the response mainly depends on the behaviour of the concrete under a 2D state of stress. Moreover, bonded connections exhibit a very high stiffness and almost the same strength as mechanical connectors. Furthermore beam simulations show that bonded connections could be modelled as perfectly bonded beams with a good accuracy. The risk of cracking in the concrete slab is also significantly reduced which may increase the durability of bonded steel–concrete composite structures compared with those equipped with mechanical connectors.