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Evaluation of Service Life of Silicate Impregnated Concrete

실리케이트 함침제를 사용한 콘크리트의 내구수명 평가

  • Kim, Hyeok-Jung (Industry Academic Cooperation Foundation, Hankyong National University) ;
  • Jang, Seung-Yup (Department of Transportation System Engineering, Graduate School of Transportation, Korea National University of Transportation) ;
  • Yoon, Yong-Sik (Department of Civil Engineering, Hannam University) ;
  • Kwon, Seung-Jun (Department of Civil Engineering, Hannam University)
  • Received : 2018.07.11
  • Accepted : 2018.11.27
  • Published : 2018.12.20

Abstract

Chloride attack, one of the major deterioration phenomena in RC(Reinforced Concrete) structure, causes corrosion of reinforcement, and this leads degradation of serviceability and structural problems. The application of silicate based impregnant to concrete surface are known for excellent constructability and cost-benefit for the maintenance of RC structure. In the work, the compressive strength and resistance of chloride diffusion for concrete were evaluated after improving property of concrete surface through two types of silicate based impregnant. Furthermore, based on the previous research and the result from the work, service life analysis was performed. After impregnating of silicate, strength and resistance of chloride diffusion were remarkably improved, and the service life increase to 159% for silicate A impregnation and 304% for silicate B impregnation, respectively.

콘크리트의 주요 열화 현상 중 하나인 염해는 철근의 부식을 야기하며 이로 인해 철근콘크리트 구조물에 사용성 및 구조성에 문제가 발생한다. 콘크리트 구조물의 유지관리를 위해 표면 함침제를 콘크리트에 적용시키는 방법은 시공성 및 경제성이 우수하다고 알려져 있다. 본 연구에서는 두 가지 종류의 실리케이트 용액을 사용하여 콘크리트의 표면의 공학적 특성을 개선시킨 후 압축강도와 염화물 확산저항성을 평가하였다. 또한, 기존의 연구와 본 실험결과를 기준으로 대상단면의 내구수명 해석을 실시하였다. 실리케이트 함침 후 콘크리트의 강도 및 염화물 확산 저항성은 크게 증가하였으며 내구수명은 실리케이트 A에서는 159%, 실리케이트 B에서는 304%로 크게 평가되었다.

Keywords

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Figure 1. Stable zone with pH variation in silicate solution[12]

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Figure 2. Photo for RCPT-ASTM C 1202

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Figure 3. Photo for RCPT preparation

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Figure 4. Compressive strength variation with silicate impregnation

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Figure 5. Passed charge variation with silicate impregnation

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Figure 6. Before and after SEM of silicate impregnation (5,000 Times magnification)

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Figure 7. Accelerated diffusion coefficient of silicate impregnated concrete

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Figure 8. Target structure for chloride ingress simulation

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Figure 9. Relationship between log-time and log-diffusion

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Figure 10. Chloride content variation with increasing service life

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Figure 11. Evaluated service life in concrete with surface impregnation

Table 1. Mix proportions for test

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Table 2. Physical properties of aggregate

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Table 3. Properties of super plasticizer

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Table 4. Components of Silicate based impregnant

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Table 5. Criteria of total passed charge[16]

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Table 6. Chloride analysis conditions for service life

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References

  1. Broomfield JP. Corrosion of Steel in Concrete: Understanding, Investigation and Repair. 1st ed. UK, London: Taylor & Francis; 1997. Chapter 1. p. 1-15.
  2. Sarja A, Vesikari E. Durability Design of Concrete Structures. 1st ed. UK, London: Taylor & Francis; 1994. Chapter 3. p. 28-52.
  3. Lee SK, Zielske J. An FHWA Special Study: Post-Tensioning Tendon Grout Chloride Thresholds. USA: Federal Highway Administration(USA); 2014 May. 200 p. Report No.: FHWA-HRT-14-039.
  4. Japan Society of Civil Engineers (JSCE). Standard Specification for Concrete Structures-Design JSCE Guidelines for Concrete 15. Japan, Tokyo: Japan Society of Civil Engineers (JSCE); 2007. p. 1-10.
  5. European Committee for Standardization. Eurocode 1: Basis of Design and Actions on Structures; EN-1991. Belgium: Comitee Europeeen de Normalization; 2000. p. 4-12.
  6. American Concrete Institute(ACI) Committee-201. Guide to Durable Concrete ACI 201R-08. (Michigan)USA,: American Concrete Institute; 2008. p. 1-14.
  7. Kwon SJ, Park SS, Lee SM, Kim JH. A study on durability improvement for concrete structures using surface impregnant. Journal of Korea Structure Maintenance Institute. 2007 Jul;11(4):79-88.
  8. Moon HY, Shin DG, Choi DS. Evaluation of the durability of mortar and concrete applied with inorganic coating material and surface treatment system. Construction and Building Materials. 2007 Feb;21(2):362-69. https://doi.org/10.1016/j.conbuildmat.2005.08.012
  9. Park SS, Kim YY, Lee BJ, Kwon SJ. Evaluation of concrete durability performance with sodium silicate impregnants. Advances in Materials Science and Engineering. 2014 Aug;2014:1-11.
  10. Emmons PH. Concrete Repair and Maintenance Illustrated: Problem Analysis, Repair Strategty, Techniques. 1st ed. USA, Wiley: RS Means Company; 1993 Oct. p. 10-29.
  11. Bank LC. Composites for Construction: Structural Design with FRP Material. 1st ed. USA, New Jersey: John Wiley & Sons; 2006. Chapter 1. p. 20-8.
  12. Kim HJ. A Study on the development of functional concrete using permeating agents and photocatalyst [dissertation]. [Jeonju (Korea)]: Chonbuk national university; 2010. 192 p.
  13. Thomas MDA, Bamforth PB. Modelling chloride diffusion in concrete: Effect of fly ash and slag. Cement and Concrete Research. 1999 Apr;29(4):487-95. https://doi.org/10.1016/S0008-8846(98)00192-6
  14. Lee HS, Kwon SJ. 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. 2017 Mar;21(2):46-52. https://doi.org/10.11112/jksmi.2017.21.2.046
  15. Lee JW, Kim KM, Bae YK, Lee JS. Study on the field application according to the early strength of the concrete admixed with polycarboxylate superplasticizer. Proceeding of Korea Concrete Institute; 2004 May 21-22; Pyoengchang (Korea). Seoul (Korea): Korea Concrete Institute; 2004. p. 200-3.
  16. Yoo JG. Durability Design of Concrete and Evaluation of Field Application on Reinforced Concrete Structure Exposed to Marine Environment [Ph.D. thesis]. [Daejeon (Korea)]: Chungnam University; 2010. 25-26 p.
  17. Oh HM. An assessment of concrete durability using inoragnic and organic/inorganic surface penetration agents [Master's thesis]. [Wonju (Korea)]: Sangji University; 2004. 44 p.
  18. Berke NS, Hicks MC. Predicting chloride profiles in concrete. CORROSION. 1994 Mar;50(3):234-9. https://doi.org/10.5006/1.3293515
  19. Yoon YS, Park JS, Hwang CS, Kwon SJ. Evaluation of relationship between strength and resistance to chloride in concrete containing fly ash with ages. Journal of the Korea Institute for Structural Maintenance and Inspection. 2017 Jul;21(4):53-60. https://doi.org/10.11112/JKSMI.2017.21.4.053
  20. Jang SY, Yoon YS, Kwon SJ. Derivation of optimum GGBFS replacement with durability design parameters. Journal of the Korea Recycled Construction Resources Institute. 2018 Mar;6(1):36-42. https://doi.org/10.14190/JRCR.2018.6.1.36
  21. Lee HS, Kwon SJ. Probabilistic analysis of repairing cost considering random variables of durability design parameters for chloride attack. Journal of the Korea Institute for Structural Maintenance Inspection. 2018 Jan;22(1):32-9. https://doi.org/10.11112/JKSMI.2018.22.1.032
  22. Thomas MDA, Bentz EC. Computer program for predicting the service life and life-cycle costs of reinforced concrete exposed to chlorides. Life365 Manual. USA: Silica Fume Association (SFA); 2002. p. 2-28.
  23. Lee SH, Kwon SJ. Experimental study on the relationship between time-dependent chloride diffusion coefficient and compressive strength. Journal of the Korea Concrete Institute. 2012 Dec;24(6):715-26. https://doi.org/10.4334/JKCI.2012.24.6.715
  24. Polder RB, van der Wegen G, Boutz M. Performance based guideline for service life design of concrete for civil engineering structures - A proposal discussed in the Netherlands. In: Baroghel-Bouny V, Andrade C, Torrent R, Scrivener K, editors. International RILEM Workshop on Performance Based Evaluation and Indicators for Concrete Durability; 2007 Spain, Madrid. France: RILEM; 2007. p. 31-9.
  25. Yoon YS. Evaluation of time-dependent chloride resistance in HPC(High Performance Concrete) containing fly ash [master's thesis]. [Daejeon (Korea)]: Hannam University; 2018. 79 p.