Design rules for composite structures with high performance steel and high performance concrete

This paper presents the results from two research projects and one Doctoral thesis regarding the design of composite beams made of high-strength structural steel and high-strength concrete: (I) The load-bearing behaviour of headed stud shear connectors in high-strength concrete is different from that in normal-strength concrete. Thus a new design approach was developed, where the load bearing capacity of the weld collar is considered. (II) When performing a plastic cross-section design both for the high-strength steel and for the high-strength concrete reductions are required to take into account their typical stress-strain behaviour. (III) The rules in Eurocode 4 (EC 4) dealing with the minimum shear connection ratios depending on the connector's ductility, the beam's span length, the loading, the cross-section and the distribution of the connectors were modified by carrying out numerical simulations.