Analisi sperimentale della connessione acciaio-calcestruzzo nelle travi reticolari miste

The interest on the use of precast composite beams (PREM) is recently increased, because of the potentiality of such structural elements in different practical applications, where traditional reinforced concrete structures cannot effectively used. The precast composite beams are a typically Italian product, available in the market with several different specific properties and very widespread in the last years. However the limited research work carried out in the past on this topic as well as the lack of European and national Codes constitutes a serious drawback from a design point of view. An important aspect to be addressed in this field is the interface behaviour between the precast steel truss and the concrete, as it influences the performances of the beams at both the ultimate and service conditions. In this context an experimental investigation, still in progress, has been carried out at the University of Salento, as part of a wider collaborative research programme between an academic staff and the industrial association, ASSOPREM. In particular, push-out tests have been performed, in order to study the interface behaviour between the bearing parts of the beams, made by a precast steel truss embedded in concrete. The obtained results have evidenced the influence of some key parameters on the ultimate capacity, slip values and ductility of the connection system. However a wider investigation is needed in order to assess reliable design indications checking also the effectiveness of the proposed test.