Vol.20, No.2, 2020, pp. 103–112
UDC:

The behaviour of concrete filled steel tube truss girders (CFST) with concrete deck slab is studied in this paper. The deflection, load capacity, failure modes and slip between the concrete slab and steel tube are reported. Eight specimens are tested under concentrated load at the mid-span, two of them without the concrete deck. The test parameters are: compressive strength (fcu) of concrete deck slab; fcu of concrete-filled steel tube for the lower chord; concrete slab's existence; location of concrete-filled tube and its existence; space between shear connectors and profile of the lower chord. Experimental results suggest that the concrete slab's existence, the strength of concrete slab, the steel section of bottom chord, and the strength of concrete that used to fill the bottom chord have a significant effect on the ultimate load, appearance of concrete slab cracks, deflection and slip. The space between shear connectors has a slight effect on the ultimate load and the deflection, but it has a great effect on the slip. Location of the concrete-filled tube has a significant effect on ultimate load and failure mode.

Keywords: concrete-filled steel tube, truss girders, concrete deck slab, shear connectors, Warren truss, composite concrete-steel