Introduction - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 38

widening existing concrete bridges with steel-concrete composite beams,
the old existing concrete bridge and new composite beam were connected
by a composite cross beamwith a composite joint. Six specimens were tested
to compensate the lack in experimental studies on the mechanical behavior
of composite joints. The study showed that, based on the existing methods,
the shear strength of the interface of the old and new concrete was calcu-
lated. It was shown that the shear failure of the interface between the old
and new concrete was the failure mode of the composite joint and the inter-
face between the steel plate and new concrete was always in good condition.
It was also shown that there was approximately no slip between the old and
new concrete before the bonding failure of the interface. The interface
between the old and new concrete had good ductility and high strength.
Based on the constitutive law of the materials, a simplified three-stage
mechanical model was proposed and the load-slip relationship was pre-
dicted. The study showed that the ultimate shear strength of the interface
was determined by the strength of the concrete, roughness degree, and fric-
tion coefficient of the interface and the normal stress could increase the ulti-
mate shear strength. In addition, the residual shear strength of the interface
can be determined by the embedded bars, and the ratio and yield strength of
the embedded bars can be the main influence factors. Based on the tests
results, a practical design method was proposed. Finally, studies on fiber-
reinforced polymer deck-on-steel girder systems are current research topics.
Davalos et al. [ 1.71 ] investigated the performance of the fiber-reinforced
polymer deck-on-steel girder system, which depends substantially on the
connectors used. The authors proposed a prototype shear connector and
showed its advantages through experimental studies and field applications.
The effectiveness of the shear connector at bridge system level, including
the static and fatigue performance of the shear connector and the bridge sys-
tem, the degree of composite action of the system, and the influence of the
partial degree of composite action on load distribution factor and effective
flange width were investigated. The authors tested a 1:3 scaled fiber-
reinforced polymer deck bridge model, with a fiber-reinforced polymer
sandwich honeycomb deck connected to steel girders using the prototype
shear connector. The experimental investigation comprised static and
fatigue load tests on the scaled bridge model. The experimental investigation
was accompanied by a numerical investigation using finite element method.
The study showed that the shear connection was able to provide partial
composite action of about 25% and sustain a cyclic fatigue loading equivalent
to 75-year bridge service life span. It was also shown that AASHTO