Experimental and numerical investigation of short-term behaviour of CLT-steel composite beams

•Development of composite action between steel beam and CLT slab.•4-Point bending tests on steel-CLT composite beams are carried out.•Efficiency of different shear connectors in steel-CLT beams is investigated.•Nonlinear finite element models for steel-CLT composite beams are developed.•Different modes of failure for steel-CLT beams are identified and discussed. This paper concerns the short-term behaviour of innovative steel-timber composite (STC) floors comprising of cross-laminated timber panels connected to steel girders by various mechanical fasteners and/or glue. The results of four-point bending tests performed on full-scale STC beams are reported and the structural behaviour (the load-deflection response, short-term stiffness, peak load capacity, and failure modes) of the proposed STC system is studied. In addition, extensive non-linear 1D and 2D finite element (FE) analyses of STC beams are carried out and the numerical results are verified against the test results. It is shown that 1D and 2D FE models are adequate in capturing the structural response of the STC beams. Using the FE and experimental results, the composite efficiency of STC beams that can significantly influence their structural behaviour beams is determined and reported in the paper.