Introduction - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 34

degrees of freedom. Shear connection of the deck was modeled using
continuous spring elements. The numerical investigation considered geo-
metric and material nonlinear behaviors of both steel and concrete materials.
Cable's sag and time-dependent effects due to load history, creep, shrinkage,
and aging of concrete were also included in the analysis. The cable-stayed
bridge investigated a 420m main span composite cable-stayed bridge under
service conditions. The failure load and the failure mechanismwere also ana-
lyzed, both at the end of construction and at long term. The influence on the
structural behavior of deck load pattern, time-dependent effects, cables'
yielding, existence of intermediate piers at the lateral spans, effective slab
width, and flexibility of the shear connection was investigated in the study.
The structural performance of orthotropic steel bridge decks renovated using
advanced composite bonded systems was the subject of experimental and
analytic investigations reported by Freitas et al. [ 1.63 ] . The proposed reno-
vation solution for orthotropic steel bridge decks studied consisted of bond-
ing a second steel plate to the existing steel deck in order to reduce the stresses
and increase the life span of the orthotropic bridge deck. The authors per-
formed a parametric study on the flexural behavior of beams representing
the renovation solution. The influences of different thickness, temperatures,
and spans were investigated. The results obtained for the stress reduction fac-
tor showed that it was independent of temperature. Also, more efficient solu-
tions can be achieved by minimizing the second steel plate thickness and
maximizing the adhesive layer thickness reducing the weight and increasing
the stiffness of the composite structure. Both elastic behavior and yield load of
the composite beams were dominated by the steel plate properties and there-
fore were not affected significantly by temperature. However, the ultimate
failure of the beams occurred by shear of the adhesive layer.
The shear connection of the unfilled composite steel grid deck was
experimentally investigated by Kim and Choi [ 1.64 ]. A total of 14 pushout
specimens having different number of holes, areas of reinforcements through
holes, and reinforcement diameters were fabricated and conducted to eval-
uate the load-slip behavior and the shear strength of the connection. The
study highlighted the effects on the shear resistance of the connection owing
to the friction force between the steel beam and the concrete, the concrete
dowel force, and the shear force due to reinforcement bars. An analytic
expression was developed based on an existing formula to predict the shear
resistance of the connection. Based on the limited test specimens for the
shear connector of the unfilled composite steel grid deck, it was concluded
that the failure of the specimen occurred in the concrete slab and the steel