Compressive behaviours of steel-UHPC-steel sandwich composite walls using novel EC connectors

Abstract

This paper reports the developments of steel-UHPC-steel sandwich composite walls with novel EC connectors (SUSSCW-ECs). The ECs in SUSSCW-ECs directly linked the two faceplates that enhance the composite action of the composite wall. Axial compression tests on 11 SUSSCW-ECs to investigate their compressive behaviours, and the selected key influencing parameters in the testing program included layout of C-channels, steel faceplate thickness, horizontal and vertical spacing of ECs, and strength of core. Under compression, the SUSSCW-ECs exhibited an elastic-plastic-recession three-stage working mechanism. Tests results show that major local buckling of faceplates ended the elastic stage, and UHPC crushing occurred at the peak compression resistance of SUSSCW-ECs. Installing the ECs with horizontal webs exhibited larger axial compression resistance of SUSSCW-ECs than those with V-web ECs. Increasing the steel faceplate thickness improved compressive behaviours of SUSSCW-ECs. Increasing horizontal and vertical spacing of EC connectors resulted in reduced ultimate compressive resistance of SUSSCW-ECs. Using UHPC improves both peak resistance and elastic stiffness of sandwich composite walls. Finally, this paper developed theoretical models to predict ultimate compressive resistance of SUSSCW-ECs, and validations against 11 test results showed their reasonable estimations.