PURPOSES : This study aimed to develop high-performance concrete repair materials for the cross-sectional repair of deteriorated bridge concrete. METHODS : To derive the optimal mix using the dry shotcrete method, experiments were conducted to develop an appropriate performance in terms of durability and watertightness based on basic experiments on materials. By mixing silica fume, GGBFS, and natural fibers, this study compared the differences in each variable. Each variable was compared using compressive strength, flexural strength, plastic shrinkage, chlorine ion penetration resistance, and freeze-thaw tests. RESULTS : By mixing silica fume and natural fibers, watertightness and durability were secured, and by adding an expansion material and polymer powder, a material that exhibited suitable performance as a repair material was developed. The material demonstrated suitable performance in terms of compressive strength, freeze–thaw resistance, plastic shrinkage crack resistance, and chlorine ion penetration resistance. CONCLUSIONS : The repair material developed in this study has a higher performance than repair mortar, and because it uses a dry shotcrete method, the process and post-processing are simpler than the wet shotcrete method; therefore, it is believed to be more efficient for repair work.

1. 연구배경 및 목적
2. 숏크리트
    2.1. 습식 숏크리트 공법
    2.2. 건식 숏크리트 공법
    2.3. 습식 및 건식 숏크리트 공법 비교
3. 실험방법 및 재료
    3.1. 골재 및 시멘트
    3.2. 자연 섬유
    3.3. 소성수축 시험 방법
    3.4. 배합표
4. 실험 결과
    4.1. 광물성 혼화재 선정을 위한 기초실험 결과
    4.2. 자연섬유 소성수축 균열 저감성 실험 결과
    4.3. 최적배합 선정을 위한 배합설계 실험 결과
    4.4. 최적배합 선정 및 실험 결과
5. 결론
REFERENCES

• 하태호(강원대학교 토목공학과 구조연구실 박사과정) | Ha TaeHo
• 최승학(강원대학교 토목공학과 구조연구실 박사과정) | Choi SeungHak
• 송창석(강원대학교 토목공학과 구조연구실 박사과정) | Song ChangSeok
• 윤경구(강원대학교 토목공학과 교수) | Yun KyoungKu (professor Room 111, Building 3, College of Engineering, 1 Gangwondaehak-gil, Chuncheon-si, Gangwon-do 24341, Korea) Corresponding author