Steel-concrete-steel sandwich composite structures-recent innovations

- Novel J-hook connectors and ULCC have been developed to enhance the structural performance of sandwich structures.
- Design formulae to predict the shear, tension and their interaction resistances of the J-hook connectors were developed.
- Experimental and analytical studies were carried out to examine the behaviours of sandwich components under extreme loads.
- SCS shells have better design resistance against high punching shear force compared to flat panels due to the arching action.
- Equations to predict the flexural, shear, punching, compressive and combined resistances of SCS components were developed.

Steel-concrete-steel (SCS) sandwich structures consisting of two steel face plates infilled with lightweight cement composite material has been developed. This paper reviews the recent innovations of SCS sandwich structures subject to blast, impact, fatigue, and static loads. Novel J-hook connectors, high strength steel plates and new lightweight cement composite materials have been considered for the development of the SCS sandwich products to improve their strength-to-weight performance. Extensive tests have been conducted to investigate the effectiveness of J-hook connectors to achieve better composite action to resist flexural, shear, impact, blast and fatigue loads. Flat and curved SCS sandwich plates under patch loading are also investigated. The experimental results are essential to understand the structural behaviour of the SCS sandwich structures and to provide data for the development of analytical models for design implementation. Design equations have been proposed to predict the shear and tensile resistances of J-hook connectors and to determine the flexural, shear, impact, blast and fatigue resistances of SCS sandwich beam. The punching shear resistance of sandwich shells and compression resistance of sandwich walls are also investigated. The accuracy of the design equations are validated by the test data and finite element analysis results.