In the last two decades, a lot of research has been devoted
to the nonlinear analysis of reinforced concrete structures
subjected to seismic forces. Reinforced concrete structures
being the most commonly used structures need proper design
and utmost care in the joint construction. During cyclic loading
of a structure, the joint should be ductile enough and capable of
dissipating large amounts of energy. A recent trend suggests
that regions of low-to-moderate seismicity like Singapore,
Eastern and Central parts of United States, Malaysia, etc.
have witnessed a rise in construction activity with precast
elements. It is already an established fact that precast structures
are advantageous in terms of productivity, economy and
quality control. However, the catastrophic failure of structures,
particularly the joints during earthquakes, showed a possible
drawback in the system. The information available on the
seismic behaviour of the hybrid-steel concrete structures in
the inelastic range is limited, thus necessitating the need for standard guidelines of seismic design of precast structures
[1–3].
A beam normally rests on the column edges, thus coinciding
with the inherent plastic hinging location. This makes the joint
most vulnerable under seismic actions if the connections are
not properly designed for the required strength and ductility.
Vertical bearing failure may occur if the concrete of the column
located above and below the beam is crushed, eventually
leading to a rigid body rotation of the beam that takes place
within the reinforced concrete column [4]. BS8110 [5], which
is the major code of practice used in Singapore, does not fully
cover the specification for precast elements. To supplement this
code, some other technical references on precast technology
such as the PCI manuals and handbooks [6–8], which contain
some research findings since the 1970s, have been used.
To augment the ongoing research in precast technology
construction, particularly the behaviour of connections in the
inelastic range, some hybrid-steel concrete joints have been
investigated in Nanyang Technological University, Singapore.
These innovative hybrid-steel concrete connections make use of
steel sections into the beam–column joint region to facilitate the
connection of precast elements. In the experimental study, one
cast-in-place and three hybrid specimens, whose connection
configurations slightly differed from each other, were tested.