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

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 SUSSCWECs. 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 SUSSCWECs. 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 SUSSCWECs, and validations against 11 test results showed their reasonable estimations. (c) 2020 Elsevier Ltd. All rights reserved.