Elastic behaviour of a tapered steel-concrete composite beam optimized for reuse

Abstract

Steel-concrete composite beams are widely used in practice because of their simple construction sequence and economic cross-section design. Reuse of traditional composite beams is not possible due to the permanent connection between the steel beam and concrete deck established by welded headed studs. To allow for fast construction, demountability and reuse of composite beams, various demountable shear connectors can be used. In this paper the results of experiments carried out on demountable and reusable tapered composite beams, consisting of a tapered steel beam and large-scale prefabricated concrete decks, are presented. The performance of various arrangements of resin-injected bolt-coupler shear connectors was considered to optimize the beneficial effect of composite action whilst minimizing the number of shear connectors. An advantage of resin-injected bolted shear connectors is that composite action is obtained instantaneously and simultaneously for all connectors. Demountability and reusability of the composite beam were successfully demonstrated experimentally. Experimental and numerical results indicated that the number of shear connectors necessary to fulfil deflection and end-slip limits can be reduced by concentrating them near the supports of a simply-supported beam. Results obtained using finite element models closely matched the experimental results in terms of deflection, stresses and curvature.

Proof of concept of a demountable steel‐concrete composite flooring system

“…6. It was confirmed experimentally that injecting epoxy resin into the bolt-to-hole clearance, instantaneous and simultaneous composite action is achieved for all of the shear connectors (6).…”

“…(6)(7)(8), Kozma et. This type of connector comes as a solution to regular embedded bolts which are vulnerable to damage during transportation and construction.…”

“…The connector is embedded in prefabricated solid concrete decks which are designed as big as practically possible to reduce the amount of work at the construction site (6). To protect the concrete edges during transportation, assembly and disassembly angle profiles are installed along the perimeter of the deck.…”

An optimisation strategy for the (in- and out-of-plane) resistance of steel beams in demountable composite floor systems

“…The development of demountable shear connectors to replace welded headed studs is increasingly gaining attention to enable the transition to a more sustainable construction sector. Experiments to establish the mechanical properties for various types of demountable shear connectors are carried out by, amongst others, Lam et al [8] and Moynihan & Allwood [9] (bolted headed studs), Wang T et al [10] (pretensioned clamping connectors), Pathirana et al [11] (blind bolts), Suwaed & Karavasilis [12] (precast connector) and Nijgh et al [13] and Kozma et al [14] (resin-injected bolted connections). The demountable shear connectors must be sufficiently stiff to generate a significant beneficial effect of the composite interaction to reduce material use by optimising the cross-section area.…”

“…The demountable shear connectors must be sufficiently stiff to generate a significant beneficial effect of the composite interaction to reduce material use by optimising the cross-section area. The material demand can be further reduced by a non-uniform distribution of the shear connectors [13,15,16]. The elastic in-plane behaviour of web-tapered monosymmetrical composite floor systems with non-uniform shear connection can be analysed using the method of Nijgh et al [17].…”