Development of a new steel section for reinforcing of steel-reinforced concrete-filled steel tubular columns

摘要

This article presents an experimental study to investigate the strength of steel-reinforced concrete-filled steel tubular (SRCFT) columns reinforced with castellated and common cruciform steel columns under compressive axial load. SRCFT columns are constructed by embedding a reinforcing steel section into the concrete-filled steel tube (CFT) column, and in this article, a new structural steel shape, namely castellated cruciform steel section, for reinforcing of SRCFT columns was designed. Investigation of SRCFT columns reinforced with castellated steel section indicates evidence of higher strength and applicability in comparison with common reinforcing steel section. A numerical investigation was also carried out with finite element analysis to study the structural behavior of SRCFT columns under lateral cyclic loading. A reasonable agreement was obtained between the results of finite element analysis and the experimental test under axial and lateral cyclic loading. The variables studied included the effect of various types of reinforcing steel sections, flange boost effects of castellated reinforcing steel section, length of columns, compressive strength of concrete, and the tube thickness. As a result, it was revealed that the SRCFT specimen reinforced with castellated cruciform steel sections was effective in enhancing the seismic performance toward more stable hysteresis curves, lower strength degradation, and higher energy dissipation as compared with SRCFT specimens reinforced with common cruciform steel sections.