Behaviors of circular concrete encased composite columns using steel plate<?xml:namespace prefix = "o" ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>

Abstract

This paper investigates the effect of different structural steel configurations on the load carrying capacity of circular composite columns using steel plate through testing nine specimens. The specimens were divided into three groups of three specimens. The specimens of the first group, normal reinforced concrete columns, served as references. While the specimens of the two remaining groups were designed in two different configurations of steel plates, namely lateral reinforcement combined with steel plates (Group 1) and open bolt-connected steel plates (Group 2), respectively. Three specimens in each group were tested as columns with eccentricities of 0 (concentric), 25 mm and 50 mm. The columns’ failure mechanisms were investigated in order to determine the strength, ductility and buckling of structural steel in columns. The study showed that Group 1presented the greatest strength and ductility due to the effect of confinement by the helix and structural steel plates. Meanwhile, the strength and ductility of columns in Group 2were not as high as expected due to the local buckling of structural steel and premature separation between the cover concrete and steel core.