Shear behaviour of steel-UHPC composite beams in waffle bridge deck

Abstract

This paper firstly proposed the steel-UHPC composite beam in waffle bridge deck system. Then, the shear behaviour of steel-UHPC composite beams in waffle bridge deck system was studied through two-point loading tests on six large scale specimens. The influences of shear span, depth of the rib, and width of the UHPC waffle slab were studied in this testing program. The experimental results reported the typical flexure and shear mode of the composite beam, and their respective ultimate strength behaviours in terms of load versus deflection (or strain) curves and load-transferring mechanism. The test results also showed that shear spans changed the failure mode of steel-UHPC composite beams. The height of the rib in the waffle slab acted less importantly than the thickness of slab on improving the shear resistance of composite beam. Theoretical models were also developed to predict the ultimate bending and shear resistances of steel-UHPC composite beams. The validations of the predictions against reported six test results showed that the developed theoretical models offered conservative estimations on shear resistance, but more accurate estimations on flexural bending resistance.