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No / In composite steel beams with precast hollow core slabs, the amount of transverse reinforcement can have a significant effect on the shear and slip capacity of the mechanical shear connectors. The issue of connector ductility becomes especially important when partial shear connection is adopted, as premature failure of the shear connectors would lead to sudden failure of the composite beam. This chapter presents its findings on the effect of transverse reinforcement on connector ductility and proposes design equations. Transverse reinforcement is used to provide ties for the slabs and confined concrete from splitting. The ductility of the shear connector, that is, slip capacity is directly affected by the amount of transverse reinforcement. Design equations presented in this chapter for estimating the shear capacity of the headed shear stud show a good correlation with the push-off test results. For full shear connection design, pre-splitting shear capacity of the headed stud can be used for the composite design, while for partial shear connection design, post-splitting shear capacity of the headed stud should be used. In general, a minimum transverse reinforcement of T16 bars should be used if partial shear connection design is used to ensure a minimum ductility of 6mm slip.

This paper evaluates the effective width of composite steel beams with precast hollowcore slabs numerically using the finite element method. A parametric study, carried out on 27 beams with different steel cross sections, hollowcore unit depths and spans, is presented. The effective width of the slab is predicted for both the elastic and plastic ranges. 8-node three-dimensional solid elements are used to model the composite beam components. The material non-linearity of all the components is taken into consideration. The non-linear load-slip characteristics of the headed shear stud connectors are included in the analysis. The moment-deflection behaviour of the composite beams, the ultimate moment capacity and the modes of failure are also presented. Finally, the ultimate moment capacity of the beams evaluated using the present FE analysis was compared with the results calculated using the rigid – plastic method.

In steel¿concrete composite beams, the longitudinal shear force is transferred across the steel flange/concrete slab interface by the mechanical action of the shear connectors. The ability of the shear connectors to transfer these longitudinal shear forces depends on their strength, and also on the resistance of the concrete slab against longitudinal cracking induced by the high concentration of shear force. Most of the research in composite construction has concentrated on the more traditional reinforced concrete and metal deck construction, and little information is given on shear capacity of the headed studs in precast hollowcore slabs. In this paper, a standard push test procedure for use with composite beams with precast hollowcore slabs is proposed. Seven exploratory push tests were carried out on headed studs in solid RC slabs to validate the testing procedures, and the results showed that the new test is compatible with the results specified in the codes of practice for solid RC slabs. Once a standard procedure is established, 72 full-scale push tests on headed studs in hollowcore slabs were performed to determine the capacities of the headed stud connectors in precast hollowcore slabs and the results of the experimental study are analysed and findings on the effect of all the parameters on connectors¿ strength and ductility are presented. Newly proposed design equations for calculating the shear connectors¿ capacity for this form of composite construction are also be given.

no / The recently published report on Rethinking Construction in the UK has highlighted the need to reduce on-site activities as part of its drive for greater efficiency, improved quality and greater certainty in the delivery of construction projects. For multi-storey buildings, the use of precast slabs in the floors - particularly if this can be done without the need for in-situ screeds - drastically reduces the volume of on-site concreting required. Although the use of precast hollow core slabs in steel framed buildings are common, their use in composite design with steel beams is relatively new. By designing the steel beams and precast hollow core slabs compositely, a reduction in beam size and overall floor depth can be achieved, which would lead to an overall reduction in construction cost. This paper summarises the recent developments and on-going research on composite construction with precast hollow core slabs.