1. Characterization of mixed assemblies

As a preliminary, it seems useful to mention the following definition, given by the EN 1994-1-1 in 1.5.2.8: "a connection between a composite element (in fact, a beam) and another element, either steel or composite (for example, a column) is considered composite when the longitudinal reinforcement (of the beam) is taken into account in the calculation for the strength and stiffness of the connection".

Conversely, when reinforcement cannot be taken into account (due, for example, to limited ductility or insufficient anchorage), the joint must be considered "metallic".