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Mechanical Properties and Impact Resistance Review of Carbon Fiber Reinforced Cement Composites with Different Fiber Contents and Fiber Lengths

섬유혼입률 및 섬유길이 변화에 따른 탄소섬유 보강시멘트 복합재료의 역학적 특성과 내충격성 검토

  • 허광희 (건양대학교 해외건설플래트학과) ;
  • 송기창 (건양대학교 의료신소재학과) ;
  • 박종건 (건양대학교 공공안전연구소) ;
  • 한윤정 (건양대학교 공공안전연구소) ;
  • 임채영 (콘개발)
  • Received : 2019.02.22
  • Accepted : 2019.06.24
  • Published : 2019.07.01

Abstract

Recently, the applications of carbon fiber have been broader than ever when it comes to such industrials as automobiles, ships, aerospace, civil engineering and architecture because of their lightweight-ness and high mechanical properties. This study analyzed mechanical properties and flexural behavior of carbon fiber reinforced cement composites(CFRC) with different fiber contents and fiber lengths, and also impact resistance by natural drop test on mortar specimens was compared and examined. In addition, contents of carbon fiber(CF) were varied by 0.5%, 1.0%, 2.0% and 3.0%. Fiber lengths was used for 6 mm and 12 mm, respectively. As a result of the test, the flow value was very disadvantageous in terms of fluidity due to the carbon fiber ball phenomenon, and the unit weight was slightly reduced. In particular, the compressive strength was decreased with increasing carbon fiber contents. On the other hand, the flexural strength was the highest with 12 mm fiber length and 2% fiber content. As the results of the impact resistance test, the specimens of plain mortar takes about 2~3 times to final fracture, while the specimens of CFRC is somewhat different depending on the increase of the fiber contents. However, when the fiber length is 12 mm and the fiber content is 2%, the impact resistance was the highest.

탄소섬유는 경량이면서 높은 기계적 특성 때문에 우주항공, 선박, 자동차, 토목 및 건축과 같은 산업분야에서 그 어느 때 보다 더 광범위하게 적용되고 있다. 본 연구는 섬유혼입률 및 섬유길이 변화에 따른 탄소섬유 보강시멘트 복합재료( CFRC)의 역학적 특성과 휨 거동을 분석하였으며, 또한 자연 낙하시험에 의한 모르타르 시편에 대한 내충격성을 비교, 검토하였다. 더불어, 탄소섬유(CF)의 혼입률은 0.5%, 1.0%, 2.0% 및 3.0%로 변화를 주었으며, 각각의 섬유길이는 6 mm와 12 mm를 사용 하였다. 실험결과, 플로우 값은 탄소섬유의 뭉침현상으로 인해 유동성 측면에서 매우 불리하였으며, 단위용적질량은 다소 감소하였다. 특히, 압축강도는 탄소섬유 혼입량이 증가함에 따라 감소하는 것으로 나타내었다. 반면 휨 강도는 섬유 길이가 12 mm이고 2% 혼입한 것이 가장 높은 휨 강도를 보였다. 내충격성 시험결과, 보통 모르타르 시편은 완전파괴까지의 낙하횟수가 2~3회 정도 걸리지만 반면 CFRC 시편은 섬유혼입량이 증가함에 따라 다소 차이가 있지만, 섬유길이가 12 mm이고 섬유혼입량 2% 인 경우 충격에 대한 저항성이 가장 높았다.

Keywords

References

  1. Boulfiza, M., Banthia, N., and Sakai, K. (2000), Application of Continuum Damage Mechanics to Carbon Fiber-Reinforced Cement Composites, ACI Materials Journal, 98(3), 245-253.
  2. Chen, P., and Chung, D.D.L. (1996), A Comparative Study of Concrete Reinforced with Carbon, Polyethylene, and Steel Fibers and Their Improvement by Latax Addition, ACI Materials Journal, 93(2), 129-133.
  3. Choi, J.I., Koh, K.T., and Lee, B.Y. (2015), Tensile Behavior of Ultra-High Performance According to Combination of Fibers, Journal of the Korea Institute for Structural of Maintenance and Inspection, 19(4), 49-56. https://doi.org/10.11112/jksmi.2015.19.4.049
  4. Chung, D.D.L. (2005), Dispersion of Shot Fibers in Cement, Journal of Materials in Civil Engineering, ASCE, 17(4), 379-383. https://doi.org/10.1061/(ASCE)0899-1561(2005)17:4(379)
  5. Heo, G.H., Park, J.G., Kim, C.G., Lee, H.J., and Choi, W.S. (2019), Impact Fracture Behavior under Temperature Variation and Compressive⋅Flexural Strength of Cement Composites using VAE Powder Polymer and PVA Fiber, Journal of the Korea Institute for Structural of Maintenance and Inspection, 23(1), 102-112. https://doi.org/10.11112/JKSMI.2019.23.1.102
  6. Korea Agency for Technology and Standard (KATS) (2007), Testing Method for Compressive Strength of Hydraulic Cement Mortar(KS L 5105), Korea Standards Association, KSA, 6(In Korea)
  7. Korea Agency for Technology and Standard (KATS) (2017), Flow Table for use in Tests of Hydraulic Cement(KS L 5111), Korea Standards Association, KSA, 6(In Korea)
  8. Korea Agency for Technology and Standard (KATS) (2009), Test Method of Impact for Building Boards(KS F 2221), Korea Standards Association, KSA, 6(In Korea)
  9. Korea Agency for Technology and Standard (KATS) (2016), Standard Test Method for Flexural Strength of oncreter(KS F 2408), Korea Standards Association, KSA, 7(In Korea)
  10. Korea Agency for Technology and Standard (KATS) (2014), Standard Test Method for Density and Absorption of Fine Aggregate(KS F 2504), Korea Standards Association, KSA, 8(In Korea)
  11. Lee, S.Y., and Park, Y.D. (1994), Mechanical Properties of High Strength Carbon Fiber Reinforced Cement Composites, RIST Report, 8(2), 321-330.
  12. Li, V.C., Wang, S., and Wu, C. (2001), Tensile Strain-Harding Behavior of Polyvinyl Alcohol Engineered Cementitious Composite(PVC-ECC), ACI Materials Journal, 98(6), 483-492.
  13. Lu, M., Xiao, H., Liu, M., Li, H., and Sun, L. (2018), Improved Interfacial Strength of SiO2 Coated Carbon Fiber in Cement Matrix, Cement and Concrete Composites, 91, 21-28. https://doi.org/10.1016/j.cemconcomp.2018.04.007
  14. Min, K.H., Lee, J.Y., Kim, M.H., and Yoon, Y.S. (2011), Behavior of Concrete Segmented Composites using Polymer Mortar under Static and Impact Loadings, Journal of the Korea Institute for Structural of Maintenance and Inspection, 15(5), 169-177. https://doi.org/10.11112/JKSMI.2011.15.5.169
  15. Oh, S.W., Jung, S.H., Chung, W.S., and Choi, Y.C. (2018), Investigation of the Effect of CNT Dosages on the Hydration and Heating Properties of Cement Composites with Low Water-to- Binder Ratio, Journal of the Korea Institute for Structural of Maintenance and Inspection, 22(6), 182-188. https://doi.org/10.11112/JKSMI.2018.22.6.182
  16. Reda Tada, M.M., and Shrive, N.G. (2001), Enhancing Fracture Toughness of High-Performance Carbon Fiber Cement Composites, ACI Materials Journal, 98(1), 168-178.
  17. Son, M.J., Kim, G.Y., Lee, S.K., Kim, H.S., and Nam, Y.S. (2017), Tensile Behavior of Hybrid Fiber Reinforced Cement Composite According to the Hooked Steel Fiber and Polyvinyl Alcohol Fiber Blending Ratio and Strain and Strain Rate, Journal of the Korea Institute for Structural of Maintenance and Inspection, 21(6), 98-105. https://doi.org/10.11112/jksmi.2017.21.6.098
  18. Wang, K., Shah, P.S., and Pariya. P. (2001), Plastic Shrinkage Cracking in Concrete Materials Influence by Fly and Fibers, ACI Materials Journal, 98(6), 454-464.
  19. Wang, W., and Chouw, N. (2017), Behavior of CFRC Beams Strengthened by FFRP Laminates under Static and Impact Loading, Construction and Building Materials, 155(2017), 956-964. https://doi.org/10.1016/j.conbuildmat.2017.08.031

Cited by

  1. Carbon Fiber Traces in Cracked Surfaces of Mortar Prisms vol.12, pp.4, 2019, https://doi.org/10.3390/app12042110