Experimental Study on Reinforced Concrete Column Incased in Prefabricated Permanent Thin-Walled Steel Form

Conventional construction methods of reinforced concrete (RC) structures generally require a long construction period and high costs due to many on-site temporary form works. In this study, a prefabricated permanent thin-walled steel form integrated with reinforcement cage (PPSFRC) was developed, and it makes for a fast-built construction by reducing the temporary form works. Axial compression tests were conducted on a total of 9 test specimens to investigate the structural performances of the newly developed columns. The proposed column construction method utilized relatively thinner steel plates compared to conventional concrete-filled tube (CFT) columns, but it was designed to have sufficient resistance performances against the lateral pressure of fresh concrete and to prevent the buckling of the thin plates by utilizing the steel angles and channel stiffeners prefabricated in the permanent thin-walled steel form. The experimental results showed that the column specimens fabricated by the PPSFRC method had better local buckling resistance and behaved in a more ductile manner compared to the conventional CFT columns. In addition, the axial strengths of the test specimens were compared with those estimated by design provisions, and the flexural moments induced by initial imperfection or accidental eccentricity of axial loads were also discussed in detail.