Development of fully composite steel-concrete-steel beam elements
Steel-Concrete-Steel (SCS) composite construction consists of two relatively thin
steel plates with the space between filled with concrete. Various forms of this
construction exist, using overlapping shear studs and single bar connectors to
provide shear reinforcement to the concrete and provide a shear transfer at the
interface. The problem with current systems that rely purely upon shear studs or
bar connectors is that they are prone to slip between the steel faceplates and
concrete core. This slip leads to a loss of composite action causing a loss of
stiffness and a reduced fatigue life.
An extensive experimental programme consisting of 32 beam specimens and 34
other small scale specimens formed the basis for the study of the behaviour of
surfaced SCS specimens under a variety of load conditions. The results of this
test program showed that surfaced SCS specimens behaved in a more composite
manner. This increase in composite action manifested itself in a number of ways.
• Reduced slip between steel plate and concrete core
• Increased stiffness of specimen
• More even crack distribution
This extensive experimental study was backed up with an analytical study to
understand and predict the behaviour of the surfaced SCS elements. This study
has led to a new method of predicting the capacity of such sections, to a greater
degree of accuracy than current methods allow. Further to this a FE parametric
study was carried out to investigate the sensitivity of the elements to changes in
the main geometrical and material variables.