The collapse of reinforced concrete (RC) frame buildings is mainly caused by the failure of columns. To prevent brittle failure of RC column, numerous studies have been conducted on the seismic performance of strengthened RC columns. Concrete jacketing method, which is one of the retrofitting method of RC members, can enhance strength and stiffness of original RC column with enlarged section and provide uniformly distributed lateral load capacity throughout the structure. The experimental studies have been conducted by many researchers to analyze seismic performance of seismic strengthened RC column. However, structures which have plan and vertical irregularities shows torsional behavior, and therefore it causes large deformation on RC column when subjected to seismic load. Thus, test results from concentric cyclic loading can be overestimated comparing to eccentric cyclic test results, In this paper, two kinds of eccentric loading pattern was suggested to analyze structural performance of RC columns, which are strengthened by concrete jacketing method with new details in jacketed section. Based on the results, it is concluded that specimens strengthened with new concrete jacketing method increased 830% of maximum load, 150% of maximum displacement and changed the failure modes of non-strengthened RC columns.

Abstract
1. 서론
2. 증설 단면의 보강 상세
3. 반복가력실험 개요
    3.1 시험체 상세
    3.2 실험 방법 및 가력 상세
4. 실험 결과 및 고찰
    4.1 균열 및 파괴양상
    4.2 하중-변위 관계
    4.3 변형률 양상
    4.4 비틀림모멘트-비틀림회전각 관계
5. 결론
References

• 문홍비(경희대학교 건축공학과) | Moon Hong Bi (Dept. of Architecture engineering, Kyung Hee University)
• 노경민(경희대학교 건축공학과) | Ro Kyong Min (Dept. of Architecture engineering, Kyung Hee University)
• 이영학(경희대학교 건축공학과 교수) | Lee Young Hak (Dept. of Architecture engineering, Kyung Hee University) Corresponding author