Experimental Study of High-Strength Bolt Connected Composite Beams with Web Openings

Abstract

There is sparse literature describing the use of high-strength bolts as shear connectors in steel–concrete composite beams with web openings. In this paper, in an attempt to ascertain the mechanical properties of prefabricated composite beams with rectangular web openings and bolt connectors, six simply supported composite beam specimens (three specimens with separated concrete panels and three with monolithic concrete slabs) have been investigated under a monotonically increasing static load. In the experiment, two kinds of concrete failure were observed in the composite beam specimens. Extrusion failure of concrete panels was observed in specimens with separated concrete panels, producing a result with close resemblance to failure of an under-reinforced concrete beam. In contrast, specimens with monolithic concrete slabs experienced shear failure. Furthermore, the observed strain distributions at the web openings of prefabricated composite beams did not conform to the assumption of plane section. In addition, the provision of web openings and tolerance of prefabricated bolt holes had substantial effects on the bearing capacity of bolt connected specimens. In conclusion, further study is needed to identify more effective and reliable design and construction methods of high-strength bolt connected composite beams with rectangular web openings.