So far, square concrete filled tubular(CFT) columns have been used in a limited width thickness ratio. The reason is that local buckling occurs in steel tube easily. Once the local buckling occurs, the confinement effect of steel tube on concrete disappears. In this study, we developed welded built-up square steel tube with reinforcement which are placed at the center of the tube width acts as an anchor. 3 specimens of slender welded built-up square CFT columns and 3 specimens of slender welded built-up square steel tube columns were manufactured with parameters of width(B) of steel tube, width thickness ratio(B/t). we conducted a experimental test on the 6 specimens under eccentric load, and evaluated the structural resistance and behavior of 6 specimens.

1. 서론
2. 구조실험
3. 실험결과
4. 분석 및 고찰
5. 결론
References

• 이성희(특허청 특허심사1국 사무기기심사과 공학박사) | Lee, Seong-Hui
• 김영호(㈜지승컨설턴트 기술연구소 공학박사) | Kim, Young-Ho
• 최성모(서울시립대학교 건축학부 교수) | Choi, Sung-Mo Corresponding author