Compressive behavior of an innovative double-steel-plate composite shear wall with iron tailings and recycled aggregate concrete

Abstract

In this paper, a double-steel-plate composite shear wall filled with iron tailings and recycled aggregate concrete (ITRAC-CSW) is proposed. It was assembled from Z-profiled steel units with shear studs welded to the inside of the flanges. Iron tailings and recycled aggregate concrete (ITRAC) consists of recycled aggregate concrete (RAC) and iron tailings sand (ITS). All aggregates of ITRAC are 100% solid waste. Five full-scale ITRAC-CSWs were fabricated and tested to investigate the axial compression performance. The parameters are whether to arrange shear studs, different inner diaphragm spacing, and the different height-to-thickness. The investigation revealed that setting shear studs increased the axial bearing capacity by 7% and its initial stiffness by 29%. Increasing the inner diaphragm spacing reduces the axial bearing capacity, initial stiffness, and ductility by approximately 5%. Elevating the height-to-thickness significantly enhanced initial stiffness and ductility with minimal impact on bearing capacity. The finite element model of ITRAC-CSW was developed and verified considering the initial defects and material nonlinearities. Based on finite element model, the failure models of ITRAC-CSW core concrete and shear studs were analyzed. Finally, the axial bearing capacity theoretical calculation method of ITRAC-CSW was established based on the five-parameter damage principle of concrete and the post-buckling strength of steel plate. The ratio of the calculated axial bearing capacity to the tested axial bearing capacity is between 0.94 and 1.00.