Eccentric Compression Strength of Rectangular Concrete-Filled Tubular Columns Using High-Strength Steel Thin Plates

An experimental study was performed to investigate the structural behavior of thin-walled rectangular concrete-filled tubular (RCFT) columns. This study mainly focused on the effects of a high-strength steel slender section on the overall eccentric compression capacity. The test parameters included the width-to-thickness ratio of steel plates, yield strength of steel plates, and use of stiffeners. Five specimens were tested under eccentric axial loading. In the slender-section specimens, despite early local buckling, significant postbuckling reserve strength developed. Consequently, the predictions of a current specification significantly underestimated the load-carrying capacity of the slender-section specimens. The specimens strengthened with vertical stiffeners exhibited enhanced strength and ductility, attaining the plastic capacity of the composite section. Furthermore, a design method of vertical stiffener was developed for high-strength steel RCFT columns. (C) 2016 American Society of Civil Engineers.