Behaviour of stud connectors in wood-concrete composite beams

The stiffening and strengthening of wooden floors with a thin collaborating concrete slab is a recent technique, which appears particularly suitable for restoration of ancient buildings. In this experimental research work a simple kind of connection is studied, suitable for practice, using materials that are normally available in the ordinary restoration yard. Tests are carried out both for studying the global behaviour of the composite beams and the local behaviour of the connections. They are conducted on two different composite beams, one with the concrete slab in direct contact with the wood beam, the other with interposed planks. Stud connectors are used which are obtained by ordinary smooth steel bars simply forced into calibrated holes drilled in the wooden beam. For the evaluation of the stiffness and resistance of the connectors pure shear tests were carried out. Experimental results concern both the local shear behaviour of the single connector and the global flexural behaviour of the composite beams. The effectiveness of the proposed technique on the flexural stiffness and strength of the composite beams is shown. Ultimate load values are in a good agreement with those calculated by classical approaches.