The experimental study on Al-fer dry connectors was carried out at the Department of Construction and Transport of the University of Padua, with the aim of evaluating the effectiveness of the mechanical behaviour of concrete slabs with a new collaborating slab. Push-out tests were carried out in the laboratory on custom samples, on elements of wooden floors reinforced with concrete slabs made on site. These tests make it possible to identify the characteristic parameters, both of resistance and capacity of deformation, for the design of the reinforcement intervention on existing and new floors; in particular, the study was aimed at calibrating the specific stiffness coefficient (connector sliding module) on which the value of the coefficient of effectiveness of the connection of the mixed composite structure depends