Flexural behavior of rectangular concrete filled steel tubular (RCFST) composite truss bridge

The rectangular concrete filled steel tubular (RCFST) composite truss bridge comprises a concrete deck and an RCFST truss girder with rectangular cross sections. To analyze the flexural behavior of this innovative type of bridge under the traffic loads in practical engineering, finite element models of whole bridge were built. The models were verified by the field test of the engineering. The numerical analysis was performed and the structural behavior during whole loading process were analyzed. The results showed that the concrete deck at the top of the pier cracked first, and the bridge reached ultimate state after the yielding of the bottom chord at mid- span. The RCFST composite truss bridge displayed superior stiffness, strength, and ductility. The contribution of the bridge components of steel truss, concrete deck and in-filled concrete on flexural strength were evaluated and compared.