콘크리트학회논문집 (Journal of the Korea Concrete Institute)

  • 제29권3호
  • /
  • Pages.307-314
  • /
  • 2017
  • /
  • 1229-5515(pISSN)
  • /
  • 2234-2842(eISSN)
한국콘크리트학회 (Korea Concrete Institute)
권호 표지
DOI QR코드

DOI QR Code

GGBFS를 혼입한 콘크리트의 재령에 따른 강도 및 염소이온 침투 저항성

Strength and Resistance to Chloride Penetration in Concrete Containing GGBFS with Ages

  • 박재성 (한남대학교 건설시스템 공학과) ;
  • 윤용식 (한남대학교 건설시스템 공학과) ;
  • 권성준 (한남대학교 건설시스템 공학과)
  • 투고 : 2017.02.27
  • 심사 : 2017.04.19
  • 발행 : 2017.06.30
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

콘크리트는 경제적이고 내구성을 가진 건설재료지만, 염해에 노출될 경우 내부 철근부식으로 인한 성능저하를 나타낸다. 콘크리트로 침투하는 염화물 이온은 수화물의 생성, 공극률 감소 등으로 인해 감소하게 되며, 주로 시간에 따라 감소하는 염화물 확산계수를 통하여 염화물 거동이 구현되고 있다. 본 연구에서는 고로슬래그 미분말(GGBFS: Ground Granulated Blast Furnace Slag)과 보통포틀랜트 시멘트(OPC: Ordinary Portland Cement)를 사용한 고성능 콘크리트를 대상으로 염화물 확산계수, 통과전하, 강도를 재령효과를 고려하여 평가하였다. 이를 위해 물-결합재비를 3가지 수준(0.37, 0.42, 0.47), 치환률을 3가지 수준으로 (0%, 30%, 50%)를 고려한 콘크리트를 제조하였으며, 28일 및 180일 재령에 따라 시험을 수행하였다. OPC를 사용한 콘크리트에서는 물-결합재비가 낮은 배합에서 염화물 확산이 감소하였으며, GGBFS를 50% 혼입한 배합에서는 물-결합재비가 높은 경우 염화물 확산성이 크게 감소하였다. 28일 재령에서 GGBFS 치환률이 50%인 경우 강도의 증가보다 빠르게 염화물 확산계수와 통과전하의 감소가 평가되었으며, 이는 초기재령에서도 효과적으로 염화물 침투에 저항할 수 있음을 나타낸다.

Concrete is a durable and cost-benefit construction material, however performance degradation occurs due to steel corrosion exposed to chloride attack. Penetration of chloride ion usually decreases due to hydrates formation and reduction of pores, and the reduced chloride behavior is considered through decreasing diffusion coefficient with time. In the work, HPC (High Performance Concrete) samples are prepared with 3 levels of W/B (water to binder) ratios of 0.37, 0.42, and 0.27 and 3 levels of replacement ratios of 0%, 30% and 50%. Several tests containing chloride diffusion coefficient, passed charge, and compressive strength are performed considering age effect of 28 days and 180 days. Chloride diffusion is more reduced in OPC concrete with lower W/B ratio and GGBFS concrete with 50% replacement ratio shows significant reduction of chloride diffusion in higher W/B ratio. At the age of 28 days, GGBFS concrete with 50% replacement ratio shows more rapid reduction of chloride diffusion than strength development, which reveals that abundant GGBFS replacement has effective resistance to chloride penetration even in the early-aged condition.

키워드

참고문헌

  1. Broomfield J. P., Corrosion of Steel in Concrete: Understanding, Investigation and Repair, E. & F.N. Spon, London, 1997, pp. 1-15.
  2. Song H. W., Pack, S. W., Lee, C. H., and Kwon, S. J., "Service Life Prediction of Concrete Structures under Marine Environment Considering Coupled Deterioration", Journal of Restoration of Building and Monument, Vol. 12, No. 1, 2006, pp. 265-284. https://doi.org/10.1515/rbm-2006-6064
  3. Thomas M. D. A., and Bamforth, P. B., "Modeling Chloride Diffusion in Concrete: Effect of Fly Ash and Slag", Cement and Concrete Research, Vol. 29, No. 4, 1999, pp. 487-495. https://doi.org/10.1016/S0008-8846(98)00192-6
  4. Korea Concrete Institute, Concrete and Environment, Kimondang press, Korea, 2011, pp. 28-36.
  5. Song, H. W., Kwon, S. J., Byun, K. J., and Park, C. K., "A Study on Analytical Technique of Chloride Diffusion Considering Characteristics of Mixture Design for High Performance Concrete Using Mineral Admixture", Journal of KSCE, Vol. 25, No. 1A, 2005, pp. 213-223.
  6. Song, H. W., and Kwon, S. J., "Evaluations of Chloride Penetration in High Performance Concrete Using Neural Network Algorithm and Micro Pore Structure", Cement and Concrete Research, Vol. 39, No. 9, 2009, pp. 814-824. https://doi.org/10.1016/j.cemconres.2009.05.013
  7. Maekawa, K., Ishida, T., and Kishi, T., "Multi-Scale Modeling of Concrete Performance", Journal of Advanced Concrete Technology, Vol. 1, No. 2, 2003, pp. 91-126. https://doi.org/10.3151/jact.1.91
  8. Al-Amoudi, O. S. B., Al-Kutti, W. A., Ahmad, S., and Maslehuddin, M., "Correlation between Compressive Strength and Certain Durability Indices of Plain and Blended Cement Concretes", Cement and Concrete Composites, Vol. 31, No. 9, 2009, pp. 672-676. https://doi.org/10.1016/j.cemconcomp.2009.05.005
  9. Rob B. Polder, Gert van der Wegen., and Michel Boutz, "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, Spain, 2006, pp. 19-21.
  10. Jeong, J. Y., Jang, S. Y., Choi, Y. C., Jung, S. H., and Kim, J. I., "Effects of Replacement Ratio and Fineness of GGBFS on the Hydration and Pozzolanic Reaction of High-strength High-volume GGBFS Blended Cement Pastes", Journal of the Korea Concrete Institute, Vol. 27, No. 2, 2015, pp. 115-125. https://doi.org/10.4334/JKCI.2015.27.2.115
  11. Jeong, J. Y., Jang, S. Y., Choi, Y. C., Jung, S. H., and Kim, S. I., "Effect of Limestone Powder and Silica Fume on the Hydration and Pozzolanic Reaction of High-Strength High-Volume GGBFS Blended Cement Mortars", Journal of the Korea Concrete Institute, Vol. 27, No. 2, 2015, pp. 127-136. https://doi.org/10.4334/JKCI.2015.27.2.127
  12. Escalante-Garcia, J. I., and Sharp, J. H., "Effect of Temperature on the Hydration of the Main Clinker Phases in Portland Cements: Part II. Blended Cements", Cement and Concrete Research, Vol. 28, No. 9, 1998, pp. 1259-1274. https://doi.org/10.1016/S0008-8846(98)00107-0
  13. Erdem, T. K., and Kirca, O., "Use of Binary and Ternary Blends in High Strength Concrete", Construction and Building Materials, Vol. 22, No. 7, 2008, pp. 1477-1483. https://doi.org/10.1016/j.conbuildmat.2007.03.026
  14. Thomas, M. D. A., and Bentz, E. C., Computer Program for Predicting the Service Life and Life-Cycle Costs of Reinforced Concrete Exposed to Chlorides, Life365 Manual, SFA, 2002, pp. 12-56.
  15. Tang, L., and Joost, G., "On the Mathematics of Time-dependent Apparent Chloride Diffusion Coefficient in Concrete", Cement and Concrete Research, Vol. 37, No. 4, 2007, pp. 589-595. https://doi.org/10.1016/j.cemconres.2007.01.006
  16. Poulsen, E., "On a Model of Chloride Ingress into Concrete, Nordic Mini Seminar- Chloride Transport", Department of Building Materials, Gothenburg. 1993, pp. 1-18.
  17. Al-alaily, H. S. and Hassan, A. A. A., "Time-dependence of Chloride Ion for Concrete Contraining Metakaolin", Journal of Building Engineering, Vol. 7, No. 9, 2016, pp. 159-169. https://doi.org/10.1016/j.jobe.2016.06.003
  18. Tang, L., Chloride Transport in Concrete, Publication P-96:6. Division of Building Materials, Chalmers University of Technology, Sweden, 1996, pp. 26-85.
  19. Lee, H. S., and Kwon, S. J., "Analysis Technique for Chloride Behavior Using Apparent Diffusion Coefficient of Chloride Ion from Neural Network Algorithm", Journal of the Korea Concrete Institute, Vol. 24, No. 4, 2012, pp. 481-490. https://doi.org/10.4334/JKCI.2012.24.4.481
  20. Ishida, T., Maekawa, K., and Kishi, T., "Enhanced Modeling of Moisture Equilibrium and Transport in Cementitious Materials Under Arbitrary Temperature and Relative Humidity History", Cement and Concrete Research, Vol. 37, No. 4, 2007, pp. 565-578. https://doi.org/10.1016/j.cemconres.2006.11.015
  21. Tang, L., "Electrically Accelerated Methods for Determining Chloride Diffusivity in Concrete-Current Development", Magazine of Concrete Research, Vol. 48, No. 176, 1996, pp. 173-179. https://doi.org/10.1680/macr.1996.48.176.173
  22. ASTM C 1202, Annual book of ASTM standards, ASTM International, Vol. 4, 2010. pp. 2-5.
  23. KS F 2711, Standard Test Method for Resistance of Concrete to Chloride Ion Penetration by Electrical Conductance, Korean Standards Service Network, 2012, pp. 1-18.
  24. Lee, S. H., Kwon. S. G., "Experimental Study on the Relationship between Time-dependent Chloride Diffusion Coefficient and Compressive Strength", Journal of the Korea Concrete Institute, Vol. 24, No. 6, 2012, pp. 715-726. https://doi.org/10.4334/JKCI.2012.24.6.715
  25. Oh, K. S., Mun, J. M., Kwon, S. J. "Chloride Diffusion Coefficient in Cold Joint Concrete with GGBFS", Journal of the Korea institute for structural maintenance and inspection, Vol. 20, No. 5, 2016, pp. 44-49. https://doi.org/10.11112/jksmi.2016.20.5.044
  26. Delagrave, A., Marchand, J., Ollivier, J. P., Julien, S., and Hazrati, K., "Chloride Binding Capacity of Various Hydra-Tedcement Paste Systems", Advanced Cement Based Materials, Vol. 6, No. 1, 1997, pp. 28-35. https://doi.org/10.1016/S1065-7355(97)90003-1
  27. Mohammed, T. U., and Hamada, H., "Relationship between Free Chloride and Total Chloride Contents in Concrete", Cement and Concrete Research, Vol. 33, No. 9, 2003, pp. 1487-1490. https://doi.org/10.1016/S0008-8846(03)00065-6
  28. Dhir, R. K., and Jones, M. R., "Development of Chloridere-Sisting Concrete Using Fly Ash", fuel, Vol. 78, No. 2, 1999, pp. 137-142. https://doi.org/10.1016/S0016-2361(98)00149-5
  29. Song, H. W., Lee, C. H., and Lee, K. C., "A Study on Chloride Binding Capacity of Various Blended Concretes at Early Age", Journal of the Korea institute for structural maintenance and inspection, Vol. 12, No. 5, 2008, pp. 133-142.