Introduction - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 2

steel plates or advanced composite laminates to carry more traffic loads. In
addition, if for any reason, such as end of their life of use or change of envi-
ronment around the area, steel bridges can be recycled. Steel bridges are
durable bridges, provided that they are well designed, properly maintained,
and carefully protected against corrosion. Finally, steel bridges can fit most of
the complex architecture designs, which in some cases are impossible to
accommodate using traditional RC bridges.
Highway bridges made of RC slabs on top of the steel beams can be effi-
ciently designed as composite bridges to get the most benefit from both the
steel beams and concrete slabs. Steel-concrete composite bridges offer addi-
tional advantages to the aforementioned advantages of steel bridges. Com-
pared to steel bridges, composite bridges provide higher strength, higher
stiffness, higher ductility, higher resistance to seismic loadings, full usage
of materials, and particularly higher fire resistance. However, these advan-
tages are maintained, provided that the steel beams and concrete slabs are
connected via shear connectors to transmit shear forces at the interface
between the two components. This will ensure that the two components
act together in resisting applied traffic loads on the bridges, which will result
in significant increases in the allowable vehicular weight limitations, ability
to transport heavy industrial and construction equipment, and possibility to
issue overload permits for specialized overweight and oversized vehicles.
One of the main advantages of having steel beams acting together with con-
crete slabs in composite bridges is that premature possible failures of the two
separate components are eliminated. For example, one of the primary modes
of failure for concrete bridges is cracking of the concrete slabs and beams in
tension, while for the steel bridges, the possible modes of failure are the for-
mation of plastic hinges and the buckling of webs or flanges. By having the
steel beams work together with the concrete slab, the whole slab will be
mainly subjected to compressive forces, which reduces the possibility of ten-
sile cracking. On the other hand, the presence of the concrete slab on top of
the steel beams eliminates the buckling of the top flange of the steel beams.
Efficient design of steel-concrete composite bridges can ensure that both the
steel beams and concrete slabs work together in resisting applied traffic loads
until failure occurs in both components, preferably at the same time, to get
the maximum benefit from both components.
Numerous topics were found in the literature highlighting different
aspects of design for steel and steel-concrete composite bridges; for exam-
ples, see [ 1.1-1.11 ] . The topics highlighted the problems associated with
the planning, design, inspection, construction, and maintenance of steel