Efficiency of mechanical floor connections on the diaphragm action of precast concrete floor/roof decks

The diaphragm effect of dry-assembled precast concrete floor and roof decks, consisting of spaced or adjacent elements, relies on mechanical floor-to-floor or floor-to-beam connections. The experimental results of a campaign of local tests carried out at Politecnico di Milano within the Safecast project (European programme FP7-SME-2007-2, Grant agreement No. 218417, 2009) on typical rigid steel angle connectors, together with innovative ductile solutions, are presented in this paper and numerical simplified non-linear macro-models are proposed. The accuracy of the model is tested through the comparison between results from dynamic non-linear analyses and experimental pseudo-dynamic tests carried out at the ELSA laboratory of the JRC of the European Commission on a full scale prototype structural arrangement. (Project ‘PRECAST STRUCTURES EC8 – Seismic behaviour of precast reinforced concrete structures with reference to EC8’ - European programme FP5, Grant agreement No. G6RD-CT-2002-00857). Further numerical analyses have been performed, modifying the geometry of the real benchmark precast structure mock-up, in order to investigate the effects of different typologies of floor-to-beam connections on the global structural response under seismic action.