Push-out tests and a new approach for the design of secondary composite beam shear connections

Most of the design approaches currently used around the world take into account the weakening effect of trapezoidal types of steel decking in the vicinity of a shear connection by applying a reduction factor to the nominal strength that the same connection would have in a solid concrete slab. Numerous push-out test results on shear connections incorporating this type of decking are presented. These demonstrate that not every shear connection incorporating profiled steel decking which is within the limits of the associated standards, can be classified as sufficiently ductile. A new and more reliable design approach is proposed which also allows for the inclusion of special reinforcing devices to overcome these brittle behaviours. The key element of this design approach is to classify the anticipated connection behaviour, with respect to its deformation capacity, into either ductile or brittle, hence ensuring satisfactory shear connection behaviour where these types of trapezoidal steel decking are used.