Axial compressive behavior of self-stressing steel slag aggregate concrete filled steel tubular columns with bond-slip damage

Abstract

The axial compressive behavior of self-stressing steel slag aggregate concrete filled steel tubular (CFST) columns with bond-slip damage is investigated in this paper. Six bond-slip damaged specimens and two undamaged specimens with different diameter-thickness ratios and expansion ratios are tested. According to the test, the outward deformation dominates the failure of the axial loaded bond-slip damaged specimens. The ultimate bearing capacity is lower with higher diameter-thickness ratio, while the increase of the expansion ratio will bring benefits to bond-slip damaged specimens. The bond-slip damage has a little influence on the ultimate capacity. The ultimate displacement will be decreased by increasing the diameter-thickness ratio. The effect of expansion ratio on the longitudinal displacement is not obvious. The stiffness degradation can be mitigated by raising the expansion ratio. The ultimate axial and circumferential strains increase as the expansion ratio increases while they decease with the diameter-thickness ratio of bond-slip damaged specimens increasing. In addition, the accuracy of existing CFST design specifications for predicting the strength of bond-slip damaged specimens is evaluated.