Compressive resistance of steel-concrete-steel sandwich composite walls with J-hook connectors.

This paper investigates the structural behaviour of Steel-Concrete-Steel (SCS) sandwich wall which consists of two external steel plates infilled with ultra-lightweight cementitious composite material. A series of compression tests consists of a wide range of parameters have been carried out on the SCS sandwich walls of different heights forming short and slender wall. The test results show that the SCS sandwich walls with J-hook connectors exhibit comparable behaviour in compressive resistance and post-peak unloading behaviour to the ones with the overlapped headed studs. The interlocking J-hook connectors play an important role in providing composite action between the steel plates and the cementitious core, and preventing or delaying the local buckling of the external steel plates. The test results are compared against the predictions by Eurocode 4 and AISC 360 methods for composite columns. It is found that the Eurocode 4 and AISC 360 methods could over-predict the compressive resistance of sandwich wall subjected to compression. A modified method is then proposed, which takes into account the effect of interlocking J-hook connectors in providing lateral restraints to the external steel plates. The predictions show a reasonable correlation with the test results. Nonlinear finite element model has been established to predict the load-displacement curves, maximum resistance and failure modes of the sandwich walls. Both the experimental and finite element results confirm that the proposed analytical formulae are conservative for design of SCS sandwich composite walls with J-hook connectors. [ABSTRACT FROM AUTHOR]