Stress transfer mechanism investigation in hybrid steel trussed–concrete beams by push-out tests

• Stress transfer mechanism in hybrid steel trussed–concrete beams
• Experimental tests on truss welding and push-out test on steel truss on HSTCBs
• Analytical prediction of welding strength
• Strength prediction in push-out tests for steel trusses in phase I
• Strength prediction in push-out tests for HSTCBs in phase II

Results of push-out tests carried out on Hybrid Steel Trussed–Concrete Beams (HSTCBs) before and after the concrete casting are presented and interpreted. Firstly, in order to check the ability of weldings before casting, tensile tests were performed on specimens reproducing different types of welded joints. Simplified design formulae were used to predict their ultimate strength. Secondly, results obtained by push-out tests on specimen representative of the beam before and after the concrete casting are presented and discussed. Finally, simplified analytical models proposed by the current European building code were adapted to the specific typology to roughly predict the ultimate strength obtained by push-out tests on specimens complete with concrete casting.