Recently, the demand for atypical structures with functions and sculptural beauty is increasing in the construction industry. Existing mold-based structure production methods have many advantages, but building complex atypical structures represents limitations due to the cost and technical characteristics. Production methods using molding are suitable for mass production systems, but production cost, construction period, construction cost, and environmental pollution can occur in small quantity batch production. The recent trend in the construction industry calls for new construction methods of customized small quantity batch production methods that can produce various types of sophisticated structures. In addition to the economic effects of developing related technologies of 3D Concrete Printers (3DCP), it can enhance national image through the image of future technology, the international status of the construction civil engineering industry, self-reliance, and technology export. Until now, 3DCP technology has been carried out in producing and utilizing residential houses, structures, etc., on land or manufacturing on land and installing them underwater. The final purpose of this research project is to produce marine structures by directly printing various marine structures underwater with 3DCP equipment. Compared to current underwater structure construction techniques, constructing structures directly underwater using 3DCP equipment has the following advantages: 1) cost reduction effects: 2) reduction of construct time, 3) ease of manufacturing amorphous underwater structures, 4) disaster prevention effects. The core element technology of the 3DCP equipment is to extrude the transferred composite materials at a constant quantitative speed and control the printing flow of the materials smoothly while printing the output. In this study, the extruding module of the 3DCP equipment operates underwater while developing an extruding module that can control the printing flow of the material while extruding it at a constant quantitative speed and minimizing the external force that can occur during underwater printing. The research on the development of 3DCP equipment for printing concrete structures underwater and the preliminary experiment of printing concrete structures using high viscosity low-flow concrete composite materials is explained.

1. 서 론
2. 적층시공 장비 및 제어시스템 개발
    2.1 적층시공 시스템의 3D프린터 장비개발
    2.2 적층시공 시스템의 배처플랜트(Batcher Plant)개발
    2.3 적층시공 시스템의 장비제어모듈 개발
    2.4 장비운영 인터페이스 설계 및 개발
3. 비정형 적층구조물 출력실험
    3.1 실험용 복합재료
    3.2 비정형 구조물 제작 실험
4. 실험결과
    4.1 시험체 제작 및 시험평가
    4.2 압축강도 시험분석
    4.3 휨강도 시험분석
5. 결 론
References

• Jun Pil Hwang(씨엠엠이 대표) | 황준필
• Hojae Lee(한국건설기술연구원 구조연구본부) | 이호재
• Hong-Kyu Kwon(남서울대학교 산업경영공학과) | 권홍규 Corresponding Author