Abstract
The structural performance of a novel hybrid precast concrete truss bridge girder proposed by Elbadry (2002) is experimentally investigated in this research. This new corrosion-resistant structural system benefits from the best characteristics of both fibre reinforced polymers (FRPs) and concrete combined in a hybrid form for construction of light and durable bridge structures. The composite bridge system comprises transversely spaced precast prestressed truss girders and a cast-in-place or precast concrete deck connected to the top of girders by means of shear connectors. The girders consist of top and bottom pretensioned concrete chords connected by vertical and diagonal concrete-filled FRP tube (CFFT) web members. The aim of this research is to experimentally investigate the structural behaviour of the proposed girder system under static and fatigue loading. A total of ten large-scale girder specimens were fabricated, of which four were tested under static loading, and six were tested under fatigue loading. The test results have shown excellent performance of the truss girders under both static and fatigue loading. Also, compression tests were performed on 69 CFFTs cast with different levels of expansive cement to evaluate its effects on the structural behaviour of the CFFTs. The tests showed significant increase in the confinement effectiveness and the load carrying capacity when expansive cement is added to the concrete mixture in CFFTs.
