Journal of the Korea institute for structural maintenance and inspection (한국구조물진단유지관리공학회 논문집)

Korea Institute for Structural Maintenance Inspection (한국구조물진단유지관리공학회)
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Analysis of Buildability and Strength Characteristics of Cement-based Composite Materials by Manufacturing Method of Laminated Specimens

적층시험체 제작 방식에 따른 시멘트계 복합재료의 적층성능 및 강도 특성 분석

  • 서은아 (한국건설기술연구원 구조연구본부) ;
  • 이호재 (한국건설기술연구원 구조연구본부)
  • Received : 2023.07.31
  • Accepted : 2023.08.29
  • Published : 2023.10.31
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Abstract

In this study, the lamination performance and strength characteristics of cement-based composite materials according to the laminated specimens manufacturing method were analyzed. As a result of evaluating the buildability according to the layer height, the highest dimensional stability was shown when the layer height was 10 mm in all parts. The mold casting specimen and the printing-Z specimen showed the same compressive strength performance at the age of 28 days. On the other hand, the compressive strength at 28 day of printing-X specimen was the lowest at 71.72 MPa, and 8% lower than that of the mold casting specimen and the printing-Z specimen. The split tensile strength of the laminated specimen may show similar performance to that of the mold casting specimen, but the strength performance may decrease by more than 10% depending on the direction of the layer and the number of layers in the specimen. As a result of the interface analysis of the laminated specimen through X-ray CT analysis, it was confirmed that pores of a certain size were distributed along the interface of the layer.

이 연구에서는 적층시험체 제작 방식에 따른 시멘트계 복합재료의 적층성능과 강도특성을 분석하였다. 레이어 높이에 따른 적층성능평가결과, 직선부과 곡선부에서 레이어 높이가 10 mm일 때 가장 높은 치수 안정성을 나타내었다. 몰드 타설 시험체와 Printing-Z 시험체의 재령 28일 압축강도는 동일한 압축강도 성능을 나타내었다. 반면, Printing-X 시험체의 재령 28일 압축강도는 71.72 MPa로 가장 낮았으며, 몰 드 제작 시험체와 Printing-Z시험체 대비 평균 8%가 낮은 압축강도를 나타내었다. 적층시험체의 쪼갬인장강도는 몰드 제작 시험체와 유사한 성능을 나타낼 수 있으나, 하중 가력방향에 대한 레이어의 방향과 시험체 내 레이어의 개수에 따라 10% 이상의 강도성능 저하현상이 나타날 수 있다. X-ray CT 분석을 통한 적층시험체의 계면 분석결과, 레이어의 계면을 따라 일정한 크기의 공극이 분포함을 확인하였다.

Keywords

Acknowledgement

본 연구는 한국건설기술연구원 구조연구본부 목적형 R&R "국민 안전과 건전한 인프라 환경을 위한 지속가능한 인프라구조 기술 연구(과제번호: 20230111)"의 시드과제 "순환자원 활용 건설 3D 프린팅 기반 저비용 변단면 거푸집 기술 개발"의 일환으로 수행된 연구임.

References

  1. AC509. (2019), 3D Automated Construction Technology for 3D Concrete Walls, ICC Evaluation Service.
  2. ASTM Standard C39. (2012), Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens, ASTM Standard International.
  3. Feng, P., Meng, X., Chen, J. F., and Ye, L. (2015), Mechanical properties of structures 3D printed with cementitious powders, Construction and Building Materials, 93, 486-497. https://doi.org/10.1016/j.conbuildmat.2015.05.132
  4. Lee, H. J., Kim, J. H., Moon, J. H., Kim, W. W., and Seo, E. A. (2019), Correlation between pore characteristics and tensile bond strength of additive manufactured mortar using X-ray computed tomography, Construction & Building Materials, 226, 712-720. https://doi.org/10.1016/j.conbuildmat.2019.07.161
  5. Lee, H. J., Kim, J. H. J., Moon, J. H., Kim, W. W., and Seo, E. A. (2020), Experimental analysis on rheological properties for control of concrete extrudability, Advances in Concrete Construction, 9(1), 93-102.
  6. Lee, H. J., Seo, E. A., Kim, W. W., Yang, J. M., and Moon, J. H. (2021), X-ray CT analysis of the cross-section of a 3D-printed deformed layer, Materials, 14(24), 7764.
  7. Le, T. T., Austin., S. A. Lim, S., Buswell, R. A., Gibb, A. G. F., and Thorpe, T. (2012), Mix design and fresh properties for high-performance printing concrete, Materials and Structures, 45(8), 1221-1232. https://doi.org/10.1617/s11527-012-9828-z
  8. Murcia, D. H., Geneeby, M., and Taha M. R. (2020), Examining the significance of infill printing pattern on the anisotropy of 3D printed concrete, Construction and Building Materials, 262, 1-14. https://doi.org/10.1016/j.conbuildmat.2020.120559
  9. Shakor, P., Sanjayan, J., Nazari, A., and Nejadi, S. (2017), Modified 3D printed powder to cement-based material and mechanical properties of cement scaffold used in 3D printing, Construction and Building Materials, 138, 398-409. https://doi.org/10.1016/j.conbuildmat.2017.02.037
  10. Seo, E. A., Lee, H. J., and Yang, K. H. (2021), Strength Characteristics of 3D Printed Composite Materials According to Lamination Patterns, Journal of the Korea Institute for Structural Maintenance and Inspection, 25(6), 193-198 (in Korean).
  11. Seo, E. A., Lee, H. J., and Yang, K. H. (2022), Evaluation of Fluidity Over Time and Mechanical Properties of Cement-based Composite Materials for 3D Printing, Journal of the Korea Institute for Structural Maintenance and Inspection, 26(4), 73-80 (in Korean).
  12. Seo, E. A., Kim, W. W., Kim, S. W., Kwon, H. K., and Lee, H. J. (2023), Mechanical properties of 3D printed concrete with coarse aggregates and polypropylene fiber in the air and underwater environment, Construction and Building Materials, 378, 131184.
  13. Seo, J. S., Lee, B. C., and Kim, Y. Y. (2019), The Effects of Void Ratio on Extrudability and Buildability of Cement-based Composites Produced by 3D Printers, Journal of the Korea Institute for Structural Maintenance and Inspection, 23(7), 104-112 (in Korean).
  14. Won, H. J. (2021), Strength characteristics of 3D printed concrete according to the stacking direction, Journal of the Korea Academia-Industrial Cooperation Society, 22(2), 632-637 (in Korean). https://doi.org/10.5762/KAIS.2021.22.12.632
  15. KCI-CT115, (2021), Standard Method of Making Compressive Strength Specimens of Underwater Additive Layering Concrete, Standards of the Korean Concrete Society (in Korean).
  16. Zhang, Y., Zhang, Y., Liu, G., Yang, Y., Wu, M., and Pang, B. (2018), Fresh properties of a novel 3D printing concrete ink, Construction and Building Materials, 174, 263-271.  https://doi.org/10.1016/j.conbuildmat.2018.04.115