KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
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Prediction of Mechanical Response of 3D Printed Concrete according to Pore Distribution using Micro CT Images

마이크로 CT 이미지를 활용한 3D 프린팅 콘크리트의 공극 분포에 따른 인장파괴의 거동 예측

  • 유찬호 (서울시립대학교 토목공학과) ;
  • 김지수 (서울시립대학교 토목공학과)
  • Received : 2023.12.01
  • Accepted : 2024.01.03
  • Published : 2024.04.01
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Abstract

In this study, micro CT images were used to confirm the tensile fracture strength according to the pore distribution characteristics of 3D printed concrete. Unlike general specimens, concrete structures printed by 3D printing techniques have the direction of pores (voids) depending on the stacking direction and the presence of filaments contact surfaces. Accordingly, the pore distribution of 3D printed concrete specimens was analyzed through quantitative and qualitative methods, and the tensile strength by direction was analyzed through a finite element technique. It was confirmed that the pores inside the 3D printed specimen had directionality, resulting in their anisotropic behavior. This study aims to analyze the characteristics of 3D concrete printing specimen and correlate them with simulation-based mechanical properties to improve performance of 3D printed material and structure.

본 연구에서는 마이크로 CT 이미지를 활용하여 3D 프린팅 콘크리트의 공극분포 특성에 따른 인장파괴 강도를 확인하였다. 3D 프린팅 기법으로 출력된 콘크리트 구조물은 일반적인 시편과는 다르게 적층방향 및 필라멘트 접촉면의 존재에 따라 공극의 방향성을 갖는다. 이에 따라 3D 프린팅 콘크리트 시편의 공극분포를 확률론적 방법으로 분석하고, 유한요소기법을 통해 방향별 인장강도를 분석하였다. 3D 프린팅된 시편 내부의 공극이 방향성을 갖는 것을 확인하였고, 출력에 의한 미세구조 특성-강도의 영향성을 평가하였다. 본 연구는 마이크로 CT 이미지 기반의 공극 분포 특성을 분석하고 시뮬레이션을 활용한 기계적 물성 평가를 수행하여 보다 향상된 성능의 적층 구조물 설계 및 재료 개발에 활용하고자 한다.

Keywords

Acknowledgement

This study was supported by the National Research Foundation of Korea, South Korea (NRF-2021R1A4A3030924). This paper has been written by modifying and supplementing the KSCE 2023 CONVENTION paper.

References

  1. Cuevas, K., Weinhold, J., Stephan, D. and Kim, J.-S. (2023). "Effect of printing patterns on pore-related microstructural characteristics and properties of materials for 3D concrete printing using in situ and ex situ imaging techniques." Construction and Building Materials, Elsevier, Vol. 405, 133220, https://doi.org/10.1016/j.conbuildmat.2023.133220. 
  2. De Soto, B. G., Agusti-Juan, I., Hunhevicz, J., Joss, S., Graser, K., Habert, G. and Adey, B. T. (2018). "Productivity of digital fabrication in construction: Cost and time analysis of a robotically built wall." Automation in Construction, Elsevier, Vol. 92, pp. 297-311, https://doi.org/10.1016/j.autcon.2018.04.004. 
  3. Han, T.-S., Zhang, X., Kim, J.-S., Chung, S.-Y., Lim, J.-H. and Christian, L. (2018). "Area of lineal-path function for describing the pore microstructures of cement paste and their relations to the mechanical properties simulated from μ-CT microstructures." Cement and Concrete Composites, Elsevier, Vol. 89, pp. 1-17, https://doi.org/10.1016/j.cemconcomp.2018.02.008. 
  4. Hong, S., Park, J. and Kim, N. (2018). "Structural stability in concrete 3D printing construction." Journal of the Korea Concrete Institute, Korea Concrete Institute, Vol. 30, No. 4, pp. 345-352, https://doi.org/10.4334/JKCI.2018.30.4.345 (in Korean). 
  5. Kim, J.-S., Chung, S.-Y., Stephan, D. and Han, T.-S. (2019). "Issues on characterization of cement paste microstructures from μ-CT and virtual experiment framework for evaluating mechanical properties." Construction and Building Materials, Elseiver, Vol. 202, pp. 82-102, https://doi.org/10.1016/j.conbuildmat.2019.01.030. 
  6. Kim, J.-H., Lee, Y. J., Jeong, H. and Kim, K. S. (2021). "Shear bond strength of 3D printed concrete layers according to water cement ratio and printing time gap." Journal of the Korea Institute for Structural Maintenance and Inspection, KSMI, Vol. 25, No. 6, pp. 199-208, https://doi.org/10.11112/jksmi.2021.25.6.199 (in Korean). 
  7. Kruger, J. and van der Westhuizen, J. P. (2023). "Investigating the poisson ratio of 3D printed concrete." Applied Sciences, MDPI, Vol. 13, No. 5, 3225, https://doi.org/10.3390/app13053225. 
  8. Lee, H., Kim, J. H. J., Moon, J. H., Kim, W. W. and Seo, E. A. (2019a). "Correlation between pore characteristics and tensile bond strength of additive manufactured mortar using X-ray computed tomography." Construction and Building Materials, Elsevier, Vol. 226, pp. 712-720, https://doi.org/10.1016/j.conbuildmat.2019.07.161. 
  9. Lee, Y. J., Song, J.-S., Choi, S.-H. and Kim, K. S. (2019b). "Buildability for concrete 3D printing according to printing time gap." Journal of the Korea Institute for Structural Maintenance and Inspection, KISMI, Vol. 23, No. 4, pp. 131-136, https://doi.org/10.11112/jksmi.2019.23.4.131 (in Korean). 
  10. Ma, G., Li, Z., Wang, L. and Bai, L. (2019). "Micro-cable reinforced geopolymer composite for extrusion-based 3D printing." Materials Letters, Elseiver, Vol. 235, pp. 144-147, https://doi.org/10.1016/j.matlet.2018.09.159. 
  11. Miehe, C., Schanzel, L.-M. and Ulmer, H. (2015). "Phase field modeling of fracture in multiphysics problems. Part I: balance of crack surface and failure criteria for brittle crack propagation in thermo-elastic solids." Computer Methods in Applied Mechanics and Engineering, Elsevier, Vol. 294, pp. 449-485, https://doi.org/10.1016/j.cma.2014.11.016. 
  12. Murcia, D. H., Genedy, M. and Taha, M. M. R. (2020). "Examining the significance of infill printing pattern on the anisotropy of 3D printed concrete." Construction and Building Materials, Elsevier, Vol. 262, 120559, https://doi.org/10.1016/j.conbuildmat.2020.120559. 
  13. Xiao, J., Ji, G., Zhang, Y., Ma, G., Mechtcherine, V., Pan, J., Wang, L., Ding, T., Duan, Z. and Du, S. (2021). "Large-scale 3D printing concrete technology: Current status and future opportunities." Cement and Concrete Composites, Elsevier, Vol. 122, 104115, https://doi.org/10.1016/j.cemconcomp.2021.104115.