Push-out tests with modern deck sheeting and realistic transverse loading

Abstract

The push-out test as proposed in EN 1994-1-1 originally was developed for solid slabs and not for composite slabs with additional steel sheeting. It leads to a load-slip behaviour of headed shear stud connectors which differs from the behaviour in the real beam. In particular, the vertical forces and negative bending moments of the composite slab at its support are ignored by this setup. Within the European research project “Development of improved shear connection rules in composite beams (DISCCO)” a total of 70 push-out tests was performed to investigate a more realistic push-out test setup. The influence of the transverse loading was investigated to develop a standard push-out test when additional steel sheeting is used. The test regime used to apply transverse loads in this investigation is described and the results of 10 push-out tests with 80 mm deep steel sheeting with pairs of 19 mm diameter headed shear stud connectors are presented. The observed bearing capacities of the shear connectors were over-predicted by the empirical reduction factor given in EN 1994-1-1 and the 6 mm criterion was not always satisfied, especially when no or only low transverse loads were applied. The application of transverse loads improved the ductility of headed shear stud connectors and the bearing capacity increased by up to 41%