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

Korea Institute for Structural Maintenance Inspection (한국구조물진단유지관리공학회)
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Characteristics of Pore Structure and Chloride Penetration Resistance of Concrete Exposed to Freezing-Thawing

동결융해 작용을 받은 콘크리트의 공극구조 및 염화물 침투저항 특성

  • 최윤석 (강릉원주대학교 토목공학과) ;
  • 원민식 ((주)제이엔티아이엔씨 기술연구소) ;
  • 이성태 (인하공업전문대학 토목환경과) ;
  • 양은익 (강릉원주대학교 토목공학과)
  • Received : 2012.08.07
  • Accepted : 2012.09.21
  • Published : 2012.11.30
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Abstract

Concrete structures are commonly exposed to freezing-thawing condition. This freezing-thawing action changes the pore structure of concrete, and it can reduce the durability of concrete. In this study, the change of the internal pore structure and durability of concrete due to freezing-thawing action are investigated. According to results, the excellent durability records were reported by the existing evaluation methods for all mixes. However, the pores, 50~100nm size in diameter, are increased in concrete specimens exposed to freezing-thawing action, and the chloride penetration resistance was significantly reduced. The linear relationship between pore structure and chloride penetration resistance was shown in water cured concrete. Meanwhile, the linear relationship was decreased when concrete is exposed to freezing-thawing condition. It is desirable to review the criterion of durability evaluation for concrete specimens exposed to freezing-fthawing and chloride attack condition, simultaneously.

콘크리트 구조물은 일반적으로 동결융해 작용을 받는 조건에 노출되고, 이러한 동결융해작용은 콘크리트의 공극구조를 변화시키고, 콘크리트의 내구성을 저하시킬 우려가 있다. 따라서 본 연구에서는 동결융해작용에 의한 콘크리트 내부공극구조 변화와 동결융해작용을 받은 콘크리트의 내구특성을 평가하고자 하였다. 실험결과, 기존의 동결융해 평가기법에 따르면 모든 배합에서 우수한 내구성능을 나타내었으나, 동결융해 작용에 노출됨에 따라 50~100nm 크기의 공극이 크게 증가하며, 콘크리트 염화물침투저항성이 저하하였다. 수중양생 콘크리트의 공극구조와 염화물 침투저항성은 선형관계를 보이지만, 동결융해작용을 받으면 내부공극구조의 변화로 선형관계가 저하하였다. 동결융해작용과 염화물침투를 동시에 받는 구조물의 내구성 평가기준에 대한 재검토가 필요할 것으로 판단된다.

Keywords

References

  1. ASTM C 457, "Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete", 2010.
  2. ASTM D 4284, "Standard Test Method for Determining Pore Volume Distribution of Catalysts by Mercury Intrusion Porosimetry", 2007.
  3. Cai, H. and Liu, X., "Freeze-Thaw Durability of Concrete: Ice Formation Process in Pores", Cement and Concrete Research, vol. 28, No. 9, 1998, pp.1281-1287. https://doi.org/10.1016/S0008-8846(98)00103-3
  4. Chendaprasirt, P., Jaturapitakkul, C. and Sinsiri, T., "Effect of fly ash fineness on compressive strength and pore size of blended cement paste", Cement and Concrete Composites, vol. 27, 2005, pp.425-428. https://doi.org/10.1016/j.cemconcomp.2004.07.003
  5. Chung, C. W., Shon, C. S. and Kim, Y. S., "Chloride ion diffusivity of fly ash and silica fume concretes exposed to freezethaw cycles", Construction and Building Materials, vol. 24, 2010, pp.1739-1745. https://doi.org/10.1016/j.conbuildmat.2010.02.015
  6. Kim, G. Y., Kim, M. H., Cho, B. S. and Lee, S. H., "The Evaluation of Surface Scaling and Resistance of Concrete to Frost Deterioration with Freezing-Thawing Action by Salt Water", Journal of the Korea Institute for Structural Maintenance Inspection, vol. 11, No. 6, 2007, pp.143-151. (in Korean)
  7. Kim, J. C., Paeng, W. S. and Moon, H. Y., "Effect of the Pore Structure of Concrete on the Compressive Strength of Concrete and Chloride Ions Diffusivity into the Concrete", Journal of the Korea Concrete Institute, vol. 15, No. 2, 2003, pp.345-351. https://doi.org/10.4334/JKCI.2003.15.2.345
  8. Korea Concrete Institute, Standard Specification for Concrete, 2009.
  9. Kwon, S. J., Lee, H. S., and Park, S. G., "Effect of Additional Water on Durability and Pore Size Distribution in Cement Mortar", Journal of the Korea Institute for Structural Maintenance Inspection, vol. 16, No. 3, 2012, pp.78-83. (in Korean)
  10. Lee, C. S., Lee, K. D., Kokubu, K. and Kwak, D. Y., "A Variation of Pore Structure of Concrete and its Relationship with Compressive Strength Cured with Various Temperatures", Journal of Korean Society of Civil Engineers, vol. 25, No. 6A, 2004, pp.1145-1150. (in Korean)
  11. Mehta, P. K., "Concrete: Microstructure, Properties, and Materials", McGraw-Hill, 2005, p.32.
  12. Moon, H. Y., Kim, H. S. and Choi, D. S., "The Characteristic of Capillary Pore and Chloride Diffusivity by Electrical Difference into Various Concrete", Journal of Korean Society of Civil Engineers, vol. 23, No. 5A, 2003, pp.969-976. (in Korean)
  13. Tang, L. and Nilsson, L. O., "Rapid determination of the chloride diffusivity in concrete by applying an electrical field", ACI Material Journal, vol. 89, No. 1, 1992, pp.49-53.
  14. Yang, C. C., "On the relationship between pore structure and chloride diffusivity from accelerated chloride migration test in cement-based materials", Cement and Concrete Research, vol. 36, 2006, pp.1304-1311. https://doi.org/10.1016/j.cemconres.2006.03.007
  15. Yang, E. I., Choi, Y. S., "Characteristics of Pore Structures and Compressive Strength in Calcium Leached Concrete Specimens", Journal of the Korea Concrete Institute, vol. 23, No. 5, 2011, pp.647-656. (in Korean) https://doi.org/10.4334/JKCI.2011.23.5.647
  16. Yang, E. I., Kim, M. Y., Yang, J. K., Park, H. G. and Choi, Y. S., "A Study on Long-Term Mechanical Properties and Durability in Metakaolin Concrete Bridge Deck", Journal of the Korea Institute for Structural Maintenance Inspection, vol. 15, No. 3, 2011, pp.125-133. (in Korean)

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