This paper describes a research project whose objective is the investigation of the applicability, implantation and the vulnerability assessment of reinforced concrete (RC) structures using lightweight sandwich floor-systems. The sandwich panels consist of two thin but strong faceplates called skins, which are supported by a thick but relatively weak core. The skins are composite laminates with a [0/90] lay-up, using EGlass fibers and resin-epoxy matrix. As this high performance skin composite laminate is fairly expensive, a cheaper and lightweight core material is exploited. The main advantage of this sandwich construction from the structural point of view, is a mass reduction of more than 70% in comparison to traditional European floor-systems. As a consequence, the design requirements in terms of both dead weights and seismic forces are significantly reduced. Furthermore, there are several advantages associated to rescue operations in case of earthquake: facilitating rescue operations since the use of lighter equipment would permit a short response time, reduction of the number of casualties associated to floor-system collapse and its removal as well as reduction of the amount of generated debris. The global ductility of the frame structure is deemed to be uncertain due to the brittle behaviour and high strength of the sandwich slab. This paper intends to evaluate the structural behaviour and the influence of the sandwich slab on the entire structure by considering a full-scale test structure as a sample. Numerical simulations are carried out using the Finite Element program ANSYS, considering material and geometric nonlinearities. The different behaviour of frame structures without and in combination with sandwich floor-systems is investigated and the collapse scenario is anticipated. The damage propagation is investigated exemplarily on the micro level (local joint damage/ buckling) as well as on the macro level (entire structure). Finally a procedure to establish a driftsafety relationship in order to determine the slab vulnerability has been developed.
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