This
paper presents a new concept for a lightweight hybrid-FRP bridge deck. The
sandwich construction consists
of three layers: a fiber-reinforced polymer
composite (FRP) sheet with T-upstands for the tensile skin, lightweight
concrete (LC) for the core and a thin layer of ultra high performance
reinforced concrete (UHPFRC) as a compression skin.
Mechanical tests on eight
hybrid beams were performed with two types of LC and two types of FRP/LC
interface: unbonded (only mechanical interlocking of LC between T-upstands) and
bonded with an epoxy adhesive. The ultimate loads of the beams increased by
104% on average due to bonding. However, the beam failure mode changed from ductile
to brittle. The beams using a LC of 44% higher density exhibited an 81%
increase in the ultimate load. The manufacturing of the beams proved to be
economic in that epoxy and concrete layers were rapidly and easily applied
wet-in-wet without intermediate curing times. The experimental results
demonstrated the feasibility of the suggested hybrid bridge deck.