Performance of SSC filled circular steel tube short columns under axial compression

Abstract

Steel slag concrete (SSC) filled steel tube (SSC-FST), reusing the waste steel slag, is a new type of composite members, therefore shows advantages in sustainable use of resources. In order to investigate axial compressive performance of this new types of SSC-FST short columns with circular section, ten specimens with varied steel slag aggregate (SSA) replacement ratio and cross-sectional steel ratio (α) were tested. The failure patterns, load versus deformation relationship and mechanical indexes (axial capacity, elastic modulus and ductility) of the specimens were recorded and analyzed. The test results indicate that, generally, replacing natural aggregates with SSAs and improving α lead to better structural performance of circular SSC-FST short column specimens. Moreover, a refined finite element (FE) model considering the initial strain of core concrete before loading was established to simulate the performance of circular SSC-FST short columns under axial compression, and the FE model was validated through experimental results from this research and the literature. Based on the verified FE model, the mechanism of axially compressed circular SSC-FST short columns was further analyzed. Finally, simplified equations were proposed to predict the axial capacity of circular SSC-FST short columns, and generally the calculated results show good agreement with the numerical/experimental results.