Travi reticolari miste - Problemi locali nella trasmissione degli sforzi

Experimental test results on the local behavior of the typical Italian typology of hybrid steel-to-concrete beam are presented and discussed in order to provide insight on transfer mechanism between different components of the beam. Preliminarily, in order to investigate on the bearing capacity of the welding and on the local instability problems that can arise in the trusses before concrete casting, tensile tests on specimens reproducing different types of welded joints, and push-out tests on bare specimen have been performed. Then, the transfer mechanism between steel trusses and concrete is investigated by means of push-out tests carried out also in displacement controlled mode. Results are presented in terms of maximum load at the failure of welded joints, load-slip curves and load-strain in truss element curves for push-out tests. Lastly, the behaviour of specimens at failure is also discussed.