Flexuralanalysis of composite one- and two-way sandwich slabs with truss-shaped connectors

Abstract

As a part of a project on the development of an indigenous building system, linear and non-linear finite element analyses (FEA) were carried out to study the behaviour of composite precast concrete sandwich panel (PCSP) under flexure in order to examine feasibility of their usage as slab elements in the construction industry. The FEA results are presented and compared with experimental published data. Good correlation was found between the results obtained from the proposed finite element model and experimentally obtained results. Different aspect ratios of slabs were analysed to study their impact on the behaviour of PCSP as slabs. The effect and orientation of the shear connectors in one or two directions were also investigated. Results in the form of load-deflection curves showed that all the panels behaved linearly before development of the first cracks. The panels were found to behave in a composite manner till the first cracking load. Results also showed that PCSP with truss steel shear connectors has a potential use as one-way slab element as its behaviour was found to be very similar to those of solid slabs especially when the two concrete wythes act in a fully composite manner. However, for practical reasons, the truss shear connectors were not recommended for two-way slabs where composite behaviour is needed in both directions to increase the structural efficiency of the PCSP as two-way acting slabs. The ultimate strength and the degree of composite action desired were found to depend to a large extent upon the stiffness of the shear connector used. An expression to assess the degree of composite action is provided.