Mechanical properties of steel-UHPC-steel slabs under concentrated loads considering composite action

• Published in: Engineering structures Vol. 222; p. 111095
• Main Authors: Wang, Zefang, Yan, Jiachuan, Lin, Youzhu, Fan, Feng, Yang, Yue
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.2020; Elsevier BV
• Subjects: Bearing capacity; Composite action; Composite materials; Composite structures; Concentrated loads; Concrete; Concrete slabs; Containment; Debonding; Design techniques; Failure analysis; Failure mechanisms; Failure modes; Fibers; Interfacial slippage; Mechanical properties; Nuclear power plants; Nuclear reactor containment; Offshore drilling rigs; Offshore engineering; Offshore platforms; Offshore structures; Protective structures; Punching; Punching shear; Punching shear cone; Slabs; Steel; Steel fibers; Steel plates; Steel-ultra high-performance concrete-steel; Studs; Tunnels; Two-way slab; Ultra high performance concrete; Two-way slab; Steel-ultra high-performance concrete-steel; Composite action; Interfacial slippage; Punching shear cone
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2020.111095

•Investigate the mechanical behavior of Steel-UHPC-Steel composite slabs under concentrated loads.•Define two failure modes of Steel-UHPC-Steel composite slabs considering composite action.•Analyze the failure mechanisms of Steel-UHPC-Steel composite slabs.•Establish a design method to predict the bearing capacity of Steel-UHPC-Steel composite slabs. Steel-concrete-steel (SCS) composite structure is widely used as the protective structure in the containment of nuclear power plants, offshore platforms, subsea tunnels, and so on. This study investigates the mechanical properties of SCS composite slabs with ultra-high performance concrete (UHPC) as the core material under concentrated loads. Five S-UHPC-S composite slabs were tested with different parameters of the spacing of headed studs and the thickness of the concrete core. Besides, one S-C-S composite slab with the normal concrete as the core material was tested for comparison. Two failure modes, i.e. punching shear failure and interfacial debonding failure, were defined considering different composite action between the concrete core and bottom steel plate. A punching shear cone was formed in punching shear failure, while interfacial debonding failure had an obvious interfacial slippage between the concrete core and bottom steel plate. The failure mechanism of these two failure modes was analyzed. Moreover, a design method to predict bearing capacities was developed, which could take the effect of the concrete core, steel fibers in UHPC, steel plates, and tie bars into consideration. In particular, a reduction coefficient was introduced to reflect the effect of composite action between the concrete core and bottom steel plate. The design method was suitable with six specimens in this study and other specimens in literature, which could provide theoretical guidance for the application of SCS composite structure in practical engineering.