Journal of the Korea Institute of Building Construction (한국건축시공학회지)

The Korean Institute of Building Construction (한국건축시공학회)
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An Experimental Study on the Chloride Attack Resistibility of Alkali-Activated Ternary Blended Cement Concrete

알칼리 활성화 3성분계 혼합시멘트의 염해 저항성에 관한 실험적 연구

  • Yang, Wan-Hee (R&D CENTER, Intchem Co., Ltd.) ;
  • Hwang, Ji-Soon (R&D CENTER, Intchem Co., Ltd.) ;
  • Jeon, Chan-Soo (Advanced Building Research Division, Korea Institute of Construction Technology) ;
  • Lee, Sea-Hyun (Advanced Building Research Division, Korea Institute of Construction Technology)
  • Received : 2016.06.01
  • Accepted : 2016.07.05
  • Published : 2016.08.20
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Abstract

The use of ternary blended cement consisting of Portland cement, granulated blast-furnace slag (GGBFS) and fly ash has been on the rise to improve marine concrete structure's resistance to chloride attack. Therefore, this study attempted to investigate changes in chloride attack resistibility of concrete through NT Build 492-based chloride migration experiments and test of concrete's ability to resist chloride ion penetration under ASTM C 1202(KS F 2271) when 1.5-2.0% of alkali-sulfate activator (modified alkali sulfate type) was added to the ternary blended cement mixtures (40% ordinary Portland cement + 40% GGBFS + 20% fly ash). Then, the results found the followings: Even though the slump for the plain concrete slightly declined depending on the use of the alkali-sulfate activator, compressive strength from day 2 to day 7 improved by 17-42%. In addition, the coefficient from non-steady-state migration experiments for the plain concrete measured at day 28 decreased by 36-56% depending on the use of alkali-sulfate. Furthermore, total charge passed according to the test for electrical indication of concrete's ability to resist chloride ion penetration decreased by 33-62% at day 7 and by 31-48% at day 28. As confirmed in previous studies, reactivity in the GGBFS and fly ash improved because of alkali activation. As a result, concrete strength increased due to reduced total porosity.

포틀랜드 시멘트, 고로슬래그 미분말, 플라이애시를 활용한 3성분계 혼합시멘트는 해양 콘크리트 구조물의 염해내구성 확보 등의 이유로 사용이 증가하고 있다. 이에 따라 본 연구에서는 보통포틀랜드 시멘트, 고로슬래그 미분말, 플라이애시를 4:4:2로 혼합한 3성분계 시멘트에 알칼리 설페이트계 활성화제(Modified Alkali Sulfate type)를 1.5~2.0% 사용할 때, NT Build 492에 의한 염화물 확산 시험과 ASTM C 1202( KS F 2271)에 의한 염소이온 침투 저항성 시험을 이용하여 콘크리트의 염해저항성의 변화를 관찰하고자 하였다. 그 결과 알칼리 설페이트계 활성화제의 활용에 따라 Plain 대비 슬럼프는 다소 감소하는 경향을 나타냈으나 재령 2일부터 재령 7일까지의 압축강도는 17~42% 향상되었다. 또한 재령 28일에 측정한 염화물 확산 계수는 알칼리 설페이트의 활용에 따라 Plain 대비 36~56% 감소하였으며, 염소이온 침투 저항성 시험에 따른 총통과전하량은 재령 7일은 33~62%, 재령 28일은 31~48% 감소하는 결과를 나타내었다. 이는 기존의 연구결과와 마찬가지로 알칼리 활성화에 의해 고로슬래그 미분말 및 플라이애시의 반응성이 향상되어 공극이 더욱 치밀해진 효과에 의한 것으로 판단된다. 향후 이와 관련하여 장기재령의 시험체를 대상으로 한 실험과 분석이 지속적으로 이루어져야 할 것으로 판단된다.

Keywords

References

  1. Mehta PK, Monteiro PJM. Concrete, Microstructure, Properties, and Materials. New York (USA):McGraw Hill; 2006. Chapter 5.16, Corrosion of Embedded Steel in Concrete; p. 176-83.
  2. Neville AM. Properties of Concrete. Essex (England):Prentice Hall; 1995. Chapter 10, Durability of concrete; p. 482-536.
  3. Bae JY, Cho SH, Shin KJ, Kim YY. A Comparative Study on Strength Development, Chloride Diffusivity and Adiabatic Temperature Rise of Marine Concrete Depending on Binder Type. Journal of the Korea Concrete institute. 2013 Aug;25(3):441-18.
  4. Song HW, Lee CH, Lee KC, Kim JH, Ann, KY. Chloride Penetration Resistance of Ternary Blended Concrete and Discussion for Durability. Journal of the Korea Concrete Institute. 2008 Aug;20(4):439-49. https://doi.org/10.4334/JKCI.2008.20.4.439
  5. Bae JY, Jang YI, Park SB, Kim YY. An Experimental Study on the Compressive Strength and Chloride Diffusivity of Mortar Produced with Multiple Mixed Cement by the Experiments Design. Journal of Material Cycles and Waste Management. 2011 Feb;28(2):165-74.
  6. Yang WH, Ryu DW, Kim WJ, Park DC, Seo CH. An Experimental Study on Early Strength and Drying Shrinkage of High Strength Concrete Using High Volumes of Ground Granulated Blast-furnace Slag(GGBS). Journal of the Korea Institute of Building Construction. 2013 Aug;13(4):391-99. https://doi.org/10.5345/JKIBC.2013.13.4.391
  7. ACI Committee 226. Ground granulated blast-furnace slag as cementations constituent in concrete. ACI Materials Journal. 1987 Jul;84(34):327-42.
  8. Hester D, McNally C, Richardson MG. Study of influence of slag alkali level on the alkali-silica reactivity of slag concrete. Construction and Building Materials. 2005 Feb;19(9):661-5. https://doi.org/10.1016/j.conbuildmat.2005.02.016
  9. Leng F, Feng N, Lu X. An experiment study on the properties of resistance to diffusion of chloride ions of fly ash and blast furnace slag concrete. Cement and Concrete Research. 2000 Jun;30:989-92. https://doi.org/10.1016/S0008-8846(00)00250-7
  10. Bae SH, Park JI, Lee KM, Choi S. Influence of Mineral Admixtures on the Diffusion Coefficient for Chloride Ion Concrete. Journal of the Korean Society of Civil Engineers. 2009 Jul;29(4):347-53.
  11. Suryavanshi AK, Swamy RN, Cardew GE. Estimation of Diffusion Coefficients for Chloride Ion Penetration into Structural Concrete. ACI Materials Journal. 2002 Sep;99(5):441-49.
  12. Shi C, Krivenko PV, Roy D. Alkali-Activated Cement and Concretes. New York (USA):Taylor & Francis; 2006. Chapter 1, Introduction; p. 1-4.
  13. Roy D. Alkali-activated cements opportunities and challenges. Cement and Concrete Research. 1999 Feb;29(2):249-54. https://doi.org/10.1016/S0008-8846(98)00093-3
  14. Ryu DW, Kim WJ, Yang WH, You JH, Ko JW. An Experimental Study on the Freezing-Thawing and Chloride Resistance of Concrete Using High Volumes of GGBS. Journal of the Korea Institute of Building Construction. 2012 Jun;12(3):.315-23.
  15. Ryu DW, Kim WJ, Yang WH, Park DC. Experimental Study on the Carbonation and Drying Shrinkage of Concrete Using High Volumes of Ground Granulated Blast-furnace Slag. Journal of the Korea Institute of Building Construction. 2012 Aug;12(4):393-400. https://doi.org/10.5345/JKIBC.2012.12.4.393
  16. Yang WH, Ryu DW, Park DC, Kim WJ, Seo CH. A study of the effect of light-burnt dolomite on the hydration of alkali-activated Portland blast-furnace slag cement. Construction and Building Materials. 2014 Jun;57:24-9 https://doi.org/10.1016/j.conbuildmat.2014.01.071
  17. Nordtest Method. Concrete, Mortar and Cement-Based Repair Materials [NT-BUILD 492]. Nordtest (Finland): Chloride Migration Coefficient from Non-Steady-State Migration Experiments; 1999.
  18. Annual Book of ASTM Standard. Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration [C1202]. West Conshohocken. PA(USA) : ASTM International; 2012.
  19. Korean Standards Association. Testing method for electrical indication of concrete's ability to resist chloride ion penetration [KS F 2711]. Seoul (Korea): Korean Standards Association; 2012.
  20. Ismail I, Bernal SA, Provis JL, Nicolas RS, Brice DG, Kilcullen AR, Hamdan S, van Deventer JSJ. Influence of fly ash on the water and chloride permeability of alkali-acticated slag mortars and concretes. Construction and Bulding Materials. 2013 Nov;13:1187-201.
  21. Elfmarkova V, Spiesz P, Brouwers HJH. Determination of chloride coefficient in blended cement mortars. Cement and concrete Research. 2015 Dec;78:190-99. https://doi.org/10.1016/j.cemconres.2015.06.014
  22. Ravikumar D, Neithalath N. Electrically induced chloride ion transport in alkali acticated slag concretes and the influence of microstructure. Cement and Concrete Research. 2013 May;47:.31-42. https://doi.org/10.1016/j.cemconres.2013.01.007
  23. Choi DS, Choi JJ. Relationship between Chloride Diffusivity and the Fundamental Properties of Concrete. Korean Society of Hazard Mitigation. 2009 Jan;9(1):15-20.
  24. Korea Concrete Institute. Curing Concrete. Seoul (Korea). Kimoondang; 2010. Chapter 6, standard method; p. 101-2.
  25. Lee CY, Kim HS, Kim JC, Cheong HM, Ahn TS. Comparison of Test Methods for Evaluation of Chloride Diffusion Coefficient in Concrete. 2008 Spring Conference of the Korea Concrete Institute. 2008 Apr;20(1):581-4.
  26. Korean Standards Association. Method of Test For Slump of Concrete [KS F 2402]. Seoul (Korea): Korean Standards Association; 2012.
  27. Korean Standards Association. Standard Test Method for Air Content of Fresh Concrete by the Pressure Method:Air Receiver Method [KS F 2421]. Seoul (Korea): Korean Standards Association; 2011.
  28. Korean Standards Association. Standard Test Method for Compressive Strength or Concrete [KS F 2405]. Seoul (Korea): Korean Standards Association; 2010.
  29. Taylor HFW. Cement chemistry. UK: Thomas Telford Publishing Company Ltd; 1990. Chapter 7.6, Actions of calcium sulphate and of alkalis; p. 236-7.
  30. Roy DM, Jiang W, Silsbee MR. Chloride diffusion in ordinary, blended, and alkali-activated cement pastes and its relation to other properties. Cement and Concrete Research. 2000 Dec;30(12):1879-84. https://doi.org/10.1016/S0008-8846(00)00406-3
  31. Saraswathy V, Muralidharan S, Thangavel K, Srinivasan S. Influence of activated fly ash on corrosion-resistance and strength of concrete. Cement and Concrete Composites. 2003 Oct;25(7):673-80. https://doi.org/10.1016/S0958-9465(02)00068-9
  32. Miranda JM, Fernandez-Jimenez A, Gonzalez JA, Palomo A. Corrosion resistance in activated fly ash mortars. Cement and Concrete Research. 2005 Jun;35(6):1210-7. https://doi.org/10.1016/j.cemconres.2004.07.030