Performance of seawater sea sand concrete-filled bimetallic tube (SSCFBT) stub columns under axial partial compression

Abstract

This study presents the experimental findings on the mechanical performance of circular seawater sea sand concrete (SSC)-filled bimetallic tube (SSCFBT) stub columns under axial partial compression. The proposed cross-sectional configuration of the bimetallic tube consists of an external layer fabricated with carbon steel and an inside layer fabricated with stainless steel, by doing so to prevent the chloride ions in SSC from corroding the external carbon steel tube-layer. Axial partial compression tests are conducted on twelve SSCFBT specimens with steel endplates and six counterparts without endplates, and the corresponding parameters include the partial compression area ratio, endplate thickness, and specimen dimensions. The test findings suggest that the two layers of the bimetallic tube exhibit effective composite actions and the SSCFBT stub columns show favorable load-carrying capacity and ductility. The effects of various parameters on the failure mechanism, load-deformation relationship, load-carrying capacity, and strain development of SSCFBT stub columns are analyzed. Finally, the suitability of using different available design codes for conventional concrete-filled steel tubes (CFST) to predict the axial partial compressive strength of SSCFBT stub columns is evaluated.