Innovative Sandwiches for Civil Applications

Physics and mechanical tests were carried out on innovative sandwiches proposed for civil applications, at the aim to know their performances. The core was obtained by embedding short mineral fibre, in different percentages, in polyurethane matrix. The results of the experimental tests were compared to what obtained on sandwiches made without any reinforcement in the polyurethane core: better behaviours were found in terms of compression strength and elastic modulus, compression energy absorption capability, impact force and energy. Good results were observed in thermal conductivity too. A very large experimental campaign was carried out at the aim to characterize the innovative sandwiches under shear load too. It was not simple to obtain the pure shear strength since the very frequent local compression failures due to the not uniform load distribution under bending tests. So, more than one kind of skin, wood, aluminium and polymeric one, was tested: a glass fibre laminate, 1,5 mm in thickness, was revealed the most appropriate one giving the possibility to have the right load distribution to observe the classical shear failure. Better behaviour was noted also in this field even if it resulted very dependent on the reinforcement percentages.