COMPRESSION CHARACTERISTICS OF RCFT COLUMNS WITH THIN-WALLED STEEL TUBE AND HIGH STRENGTH CONCRETE

Abstract

It is clear from the former researches on reinforced concrete filled steel tubular (RCFT) structures that RCFT structures have higher strength and deformation capacity than concrete filled steel tubular (CFT) structures. However, in the case of actual applications to large-scaled structures, the thin-walled steel tube and high strength concrete must be used from the view point of economic condition. Therefore, in this study, compression tests of RCFT columns which were made by thin-walled steel tube in cooperation with high strength concrete were carried out, meanwhile corresponding tests of CFT, reinforced concrete (RC), pure concrete and steel tube columns were conducted to compare with RCFT. By a series of comparison and analysis, characteristics of RCFT columns were clarified, and following conclusions were drawn: RCFT columns have better shear-resistibility than CFT columns; with RCFT columns, excellent bearing capacity can be achieved in plastic zone by combining the thin-walled steel tube with high strength concrete. This has economical meaning while RCFT was applied to actual construction.