Civil Engineering Reference
In-Depth Information
Chapter 2
Shear connection
2.1
Introduction
The established design methods for reinforced concrete and for structural
steel give no help with the basic problem of connecting steel to the con-
crete. The force applied to this connection is mainly, but not entirely,
longitudinal shear. As with bolted and welded joints, the connection is a
region of severe and complex stress that defies accurate analysis, and so
methods of connection have been developed empirically and verified by
tests. They are described in Section 2.4.
The simplest type of composite member used in practice occurs in floor
structures of the type shown in Fig. 3.1. The concrete floor slab is con-
tinuous over the steel I-sections, and is supported by them. It is designed
to span in the
y
-direction in the same way as when supported by walls or
the ribs of reinforced concrete T-beams. When shear connection is pro-
vided between the steel member and the concrete slab, the two together
span in the
x
-direction as a composite beam. The steel member has not
been described as a 'beam', because its main function at mid-span is to
resist tension, as does the reinforcement in a T-beam. The compression
is assumed to be resisted by an 'effective' width of slab, as explained in
Section 3.5.1.
In buildings, but not in bridges, these concrete slabs are often com-
posite with profiled steel sheeting (Fig. 2.8), which rests on the top flange
of the steel beam. Other types of cross-section that can occur in composite
beams are shown in Fig. 2.1.
The ultimate-strength design methods used for shear connection in
beams and columns in buildings are described in Sections 3.6 and 5.6.6,
respectively.
The subjects of the present chapter are: the effects of shear connection
on the behaviour of very simple beams, current methods of shear connec-
tion, standard tests on shear connectors, and shear connection in com-
posite slabs.
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