2. COMPOSITE DECK PROTOTYPES
2.1 Conventional Reinforced-Concrete Bridge Deck System
The conventional reinforced-concrete deck (Bridge #1) was designed by the Ohio Department of
Transportation (ODOT) for the benchmark response of the set of FRP bridge decks. This deck
prototype had dimensions of 1.828 6.100 0.178 m (72 240 7 in.) and was connected to
the supporting W36x182 steel girders using shear studs. In the direction perpendicular to the
girders, top steel reinforcing bars (No. 5) were placed in the concrete slab with a spacing of 133
mm (5.25 in.) and a cover of 38 mm (1.5 in.). A bottom reinforcement layer was placed with a
spacing of 152-mm (6-in.). In the direction parallel to the girders, top distribution reinforcement
(No. 4 bar) and bottom distribution reinforcement (No. 5 bar) was used. The concrete
compressive strength was 29.3 MPa (4250 psi).
2.2 Hybrid FRPConcrete Bridge Deck System
The hybrid FRP-concrete deck system (Bridge #2) had FRP pultruded panels that were used for
stay-in-place formwork and concrete reinforcement (Figure 2). The pultruded panels had a width
of 457 mm (18 in.) and two stiffening tubular cells with a height of 76 mm (3 in.). This FRP
composite material was reinforced with E-glass roving and directional-bias fabric in a polyester-
vinyl ester resin blend.
Concrete was cast on the FRP composite panels to attain the specified slab depth of 203
mm (8 in.). Top reinforcement in both directions was provided by non-corrosive E-glass rebar
with deformations to improve the bond with the concrete. The deck was connected to the
supporting steel girders using shear studs. After placing the pultruded panels on the steel girders,
shear studs were welded. This test specimen had dimensions of 1.828 6.100 0.203 m (72
240 8 in.). A concrete haunch was placed between the FRP deck panels and the steel girders.
2.3 FRP Bridge Deck Fabricated by the VARTM Process
Bridge #3 was fabricated by the VARTM (Vacuum Assisted Resin Transfer Molding) process
(Figure 2). The deck was composed of face sheets reinforced with multi-axial stitched E-glass
fabric (0/90/45) (BTI, QM6408), and an integral cell core that was wrapped with an E-glass
fabric. The resin matrix was vinyl ester resin (Dow Derakane 411). The deck prototype had
dimensions of 1.828 6.100 0.203 m (72 240 8 in.). Two panels of 0.914 m (36 in.) in
width and 6.100 m (240 in.) in length were connected with a longitudinal joint (perpendicular to
the girder direction) to form the deck prototype while providing a smooth surface.
2.4 FRP Bridge Deck System Fabricated by the Pultrusion Process
Bridge #4 was made of FRP composite profiles with constant cross-section fabricated by the
pultrusion process (Figure 2). In a second operation the components are interlocked and bonded
using a toughened adhesive. In this way large panels can be fabricated and shipped to the
construction site. This deck is typically highly orthotropic with the main stiffness direction
corresponding to the axis of the pultruded profiles, which was perpendicular to the supporting
girder direction. The cross-section was composed of hexagonal and double trapezoidal profiles
(Lopez-Anido et al. 2001).