This study reports an experimental and analytical exploration of concrete columns laterally confined with Fe-based shape-memory alloy (Fe-SMA) spirals. For performing experiments, Fe-SMA rebars with a 4% prestrain and diameter of 10 mm were fabricated and concrete columns with internal Fe-SMA spiral reinforcement were constructed with a diameter of 200 mm and height of 600 mm. An acrylic bar with an attached strain gauge was embedded in the center of the specimen to measure local strains. Experimental variables encompassed the Fe-SMA spiral reinforcement, spacing, and activation temperature. Uniaxial compression tests were conducted after applying active confinement to the concrete columns through electrical-resistance heating. Notably, as the Fe-SMA spiral spacing decreased, the local failure zone length and compressive fracture energy of the prepared specimens increased. Additionally, a model incorporating compressive fracture energy was proposed to predict the stress–strain behavior of the. This model, accounting for active and passive confinement effects, demonstrated accurate predictions for the experimental results of this study as well as for previously reported results.

1. 서 론
2. 일축 압축실험
    2.1 실험체 개요
    2.2 사용 재료
    2.3 실험 방법
3. 실험 결과
    3.1 국소파괴영역길이
    3.2 압축파괴에너지
4. 응력-변형률 모델
    4.1 유효 횡 구속응력
    4.2 최대 응력 및 최대 응력 시 변형률
    4.3 국소파괴영역길이 및 압축파괴에너지 정식화
    4.4 응력-변형률 모델 제안
    4.5 제안 모델 검증
5. 결 론
감사의 글
REFERENCES

• 지상원(충북대학교 토목공학과 박사과정) | Ji, Sangwon (Ph.D. Student, Department of Civil Engineering, Chungbuk National University, Cheongju, Korea)
• 홍기남(충북대학교 토목공학부 교수) | Hong, Kinam (Professor, Department of Civil Engineering, Chungbuk National University, Cheongju, Korea)