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

  • 제22권4호
  • /
  • Pages.52-59
  • /
  • 2018
  • /
  • 2234-6937(pISSN)
  • /
  • 2287-6979(eISSN)
한국구조물진단유지관리공학회 (Korea Institute for Structural Maintenance Inspection)
권호 표지
DOI QR코드

DOI QR Code

1년 양생 조건의 Fly Ash를 혼입한 고성능 콘크리트의 시간의존적 염해저항성 평가

Evaluation of Time-Dependent Chloride Resistance in HPC Containing Fly Ash Cured for 1 Year

  • 윤용식 (한남대학교 건설시스템공학과) ;
  • 권성준 (한남대학교 건설시스템공학과)
  • 투고 : 2018.03.15
  • 심사 : 2018.06.30
  • 발행 : 2018.07.01
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

철근콘크리트 구조물의 대표적인 열화현상인 염해를 억제하고자 여러 가지 연구가 진행되었는데, 그 중에서 혼화재료를 콘크리트에 혼입하여 사용하는 방법이 대표적으로 알려져 있다. 본 연구에서는 대표적인 콘크리트 혼화재료인 플라이애시를 혼입한 콘크리트와 OPC 콘크리트에 대하여 3가지 수준의 물-결합재비(37%, 42%, 47%)를 고려해 내구성능 평가를 실시하였다. 각 목표 재령일에서 Tang's method에 준하여 촉진 염화물 확산계수 측정 실험을, ASTM C 1202에 준하여 통과전하량 측정 실험을, KS F 2405에 준하여 압축강도 실험을 실시하였다. 또한, 기존의 연구결과인 재령 28일의 실험결과를 참고하여 확산계수에 대한 시간의존성지수(m)를 도출하여 고찰하였으며, 장기재령의 압축강도와 시간의존성지수 간의 상관관계를 평가하였다. 재령 49일부터 플라이애시 혼입 콘크리트에서 OPC 콘크리트 대비 개선된 염해저항성능을 나타내었으며 이는 포졸란 반응에 의해 생성된 불용성의 수화물이 원인으로 사료된다. 플라이애시 혼입 콘크리트에서 OPC 콘크리트 대비 약 1.5배 높은 시간의존성지수를 나타내었으며, 압축강도와의 상관관계 평가 결과, OPC 콘크리트는 압축강도가 증가할수록 선형적으로 시간의존성지수가 증가하는 경향을, 플라이애시 콘크리트는 압축강도가 증가할수록 선형적으로 시간의존성지수가 약간 감소하는 경향을 나타냈다.

To control chloride attacks which is a representative deterioration in RC(Reinforced Concrete) structures, many studies have been conducted. Above all, a method using mineral admixture was known to be effective for corrosion protection. In this study, durability test about chloride attacks was carried out for concrete specimens containing FA(Fly Ash)-representative concrete mineral admixture and OPC concrete specimens considering 3 different levels of W/B(Water to Binder). Accelerated chloride diffusion coefficient tests referred to Tang's method, total passed charge tests referred to ASTM C 1202, and compressive strength tests based on KS F 2405 were performed at each target age day. Also, based on previous studies of 28 days, time-parameter which is a key parameter for diffusion behavior is evaluated and its relations with compressive strength at the age of 365 days is evaluated. After the age of 49 days, chloride resistance of FA concrete is much improved than that of OPC concrete, which arose out of stable hydrates due to pozzolan reaction of fly ash. Time-parameter of FA concrete is evaluated to be about 1.5 times larger than that of OPC concrete. Also, time-parameter of FA concrete has a linearly decreasing relation while that of OPC concrete has a linearly increasing relation with compressive strength development.

키워드

참고문헌

  1. Al-Amoudi, O. S. B., and Maslehuddin, M. (1993), The effect of chloride and sulfate ions on reinforcement corrosion, Cement and Concrete Research, 23(1), 139-146. https://doi.org/10.1016/0008-8846(93)90144-X
  2. ASTM C 1202. (2005), Standard Test Method for Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration, American Society for Testing and Materials.
  3. Broomfield, J. P. (1997), Corrosion of Steel in Concrete: Understanding, Investigation and Repair, E&FN, London, 1-15.
  4. Chun, J. H., Ryu, H. S., Yoon, Y. S., and Kwon, S. J. (2017), Crack and Time Effect on Chloride Diffusion Coefficient in Nuclear Power Plant Concrete with 1 Year Curing Period, Journal of the Korea Institute for Structural Maintenance and Inspection, 21(6), 83-90. https://doi.org/10.11112/JKSMI.2017.21.6.083
  5. Jung, S. H., Choi, Y. C., Moon, K. D., and Choi, Y. J. (2012), Development of green construction materials utilizing high volume coal combustion products, Proceedings of the Korean Recycled Construction Resource Institute, 12(1), 169-172.
  6. Ko, J. H., Yoo, S. Y., Koo, J. S., Moon, H. J., Kim, J. J., and Park, S. J. (2012), An Experimental Study to Apply for High-Rise Construction according to Various Technical Properties of Ultra High-Strength Concrete, Journal of the Architectural Institute of Korea : Structure & Construction, 28(1), 85-92.
  7. KS F 2405. (2015), Standard Test Method for Compressive Strength of Concrete, KSSN, 1-3.
  8. KS L 5405. (2016), Fly ash, KSSN, 1-8.
  9. Kwon, S. J. (2016), Effect of Time-dependent Diffusion and Exterior Conditions on Service Life Considering Deterministic and Probabilistic Method, Journal of the Korea Institute for Structural Maintenance and Inspection, 20(6), 65-72. https://doi.org/10.11112/jksmi.2016.20.6.065
  10. Kwon, S. J., Park, S. S., Lee, S. M., and Kim, J. H. (2007), A Study on Durability Improvement for Concrete Structures Using Surface Impregnant, Magazine of the Korea Institute for Structural Maintenance and Inspection, 11(4), 79-88.
  11. Kwon, S. O., Bae, S. H., Lee, H. J., and Jung, S. H. (2014), Characteristics for Reinforcement Corrosion and Chloride Ion Diffusion of High Volume Fly Ash Concrete, Journal of the Korean Recycled Construction Resources Institute, 2(1), 34-39. https://doi.org/10.14190/JRCR.2014.2.1.034
  12. Lee, H. S., and Kwon, S. J. (2017), Analysis Technique on Time-dependent PDF (Probability of Durability Failure) Considering Equivalent Surface Chloride Content, Journal of the Korea Institute for Structural Maintenance and Inspection, 21(2), 46-52.
  13. Lee, S. H., and Kwon, S. J. (2012), Experimental Study on the Relationship between Time-Dependent Chloride Diffusion Coefficient and Compressive Strength, Journal of the Korea Concrete Institute, 24(6), 715-726. https://doi.org/10.4334/JKCI.2012.24.6.715
  14. Lee, S. Y., and Lee, J. B. (2000), Application of electrochemical corrosion measurement techniques for rebars in concrete, Journal of the Corrosion Science Society of Korea, 29(6), 313-324.
  15. Metha, P. K., and Monteiro, P. J. M. (1993), Concrete-Structure, Properties and Materials, 2nd edition, Prentice Hall, New-Jersey, 271-284.
  16. Nath, P., and Sarker, P. (2011), Effect of Fly Ash on the Durability Properties of High Strength Concrete, Procedia Engineering, 14, 1149-1156. https://doi.org/10.1016/j.proeng.2011.07.144
  17. Oh, K. S., Moon, J. M., and Kwon, S. J. (2016), Chloride Diffusion Coefficients in Cold Joint Concrete with GGBFS, Journal of the Korea Institute for Structural Maintenance and Inspection, 20(5), 44-49. https://doi.org/10.11112/jksmi.2016.20.5.044
  18. Oh, K. S., Moon, J. M., Park, K. T., and Kwon, S. J. (2016), Evaluation of Load Capacity Reduction in RC Beam with Corroded FRP Hybrid Bar and Steel, Journal of the Korea Institute for Structural Maintenance and Inspection, 20(2), 10-17. https://doi.org/10.11112/JKSMI.2016.20.2.010
  19. Polder, R. B., van der Wegen, G., and Boutz, M. (2007), Performance based guideline for service life design of concrete for civil engineering structures - A proposal discussed in the Netherlands, International RILEM Workshop on Performance Based Evaluation and Indicators for Concrete Durability, RILEM, Madrid, 31-39.
  20. RILEM. (1994), Durability Design of Concrete Structures, Report of RILEM Technical Committee 130-CSL, E&FN, London, 28-52.
  21. SERI. (2003), Evaluation of chloride ion diffusion characteristics of high durability concrete, Samsung Engineering Research Institute, Final report.
  22. Song, H. W., Kwon, S. J., Byun, K. J., and Park, C. K. (2005), A Study on Analytical Technique of Chloride Diffusion Considering Characteristics of Mixture Design for High Performance Concrete using Mineral Admixture, Journal of the Korean Society of Civil Engineers, 25(1A), 213-223.
  23. Tang, L., and Nilsson, L. O. (1992), Rapid Determination of the Chloride Diffusivity in Concrete by Applying an Electrical Field, ACI Materials journal, 89(1), 49-53.
  24. Thomas, M. D, A., and Bentz, E. C. (2002), Computer Program for Predicting the Service Life and Life-cycle Costs of Reinforced Concrete Exposed to Chlorides(Life365 Manual), SFA.
  25. Thomas, M. D. A., and Bamforth, P. B. (1999), Modelling chloride diffusion in concrete: Effect of fly ash and slag, Cement and concrete research, 29(4), 487-495. https://doi.org/10.1016/S0008-8846(98)00192-6
  26. Yoo, J. G. (2010), Durability Design of Concrete and Evaluation of Field Application on Reinforced Concrete Structure Exposed to Marine Environment, Ph.D. dissertation, Daejeon, Chungnam University, Department of Architectural Engineering.