DOI QR코드

DOI QR Code

Experiment on Chloride Adsorption by Calcium Aluminate Phases in Cement

시멘트내 칼슘 알루미네이트 상에 의한 염소이온의 흡착반응 연구

  • Yoon, In-Seok (Dept. of Construction Info. Eng., Induk University)
  • 윤인석 (인덕대학교 건설정보공학과)
  • Received : 2017.04.06
  • Accepted : 2017.06.27
  • Published : 2017.08.31

Abstract

Friedel's salt is an important product of chemical adsorption between cement hydrate and chloride ions because it contains chlorine in its structure. When cement reacts with water in the presence of chloride ions, the $C_3A$ phase, and $C_4AF$ phase react with chloride to produce Friedel's salt. If chloride ions penetrate into concrete from external environments, many calcium aluminate hydrates, including AFm, can bind chloride ions. It is very important, therefore, to investigate the chloride binding isotherm of $C_3A$ phase, $C_4AF$ phase, and AFm phase to gain a better understanding of chloride binding in cementitious materials. Meanwhile, the adsorption isotherm can provide us with the fundamental information for the understanding of adsorption process. The experimental results of the isotherm can supply not only the quantitative knowledge of the cement-Friedel's salt system, but also the mechanism of adsorption and the properties of their interactions. The purpose of this study is to explore the time dependant behaviors of chloride ions adsorption with $C_3A$, $C_4AF$ and AFm phases. The chloride adsorption isotherm was depicted with Langmuir isotherm and the adsorption capacity was low in terms of the stoichiometric point of view. However, the chloride adsorption of AFm phase was depicted with Freundlich isotherm and the value was very low. Since the amount of the adsorption was governed by temperature, the affecting parameters of isotherm were expressed as a function of temperature.

시멘트내 $C_3A$상과 $C_4AF$상은 염소이온과 반응하여 프리델염을 생성한다. 프리델염은 구조체에서 염소를 포함하기 때문에 염소이온의 흡착에 매우 중요하다. 외부에서 염소이온이 침투하면, 칼슘 알루미네이트 수화물은 염소이온을 고정하므로, $C_3A$상과 $C_4AF$상 및 AFm상의 염소 흡착 거동을 고찰하는 것은 고정화 현상을 이해하는데 매우 중요하다. 한편, 흡착 등온은 시멘트와 프리델염의 상호관계에서 정량적인 지식을 제공할 뿐만 아니라 그 상호관계의 특성을 이해하는데 매우 중요하다. 본 연구의 목적은 $C_3A$상, $C_4AF$상 및 AFm상의 염소이온 흡착 거동을 고찰하는데 있다. $C_3A$상과 $C_4AF$상의 흡착등온은 이론적 화학당량보다 다소 낮았으며 Langmuir 흡착등온식으로 표현할 수 있었다. AFm상의 흡착등온은 이론적 화학당량보다 매우 낮았으며, Freundlich 흡착등온식으로 표현하였다. 또한 흡착등온 모델에서 온도의 영향 매개변수를 실험범주내에서 온도의 함수로 제안하였다.

Keywords

Acknowledgement

Supported by : 한국연구재단

References

  1. Yoon, I. S., "Theoretical Analsis of Critical Chloride Content in (Non) Carbonated Concrete Based on Characterstics of Hydration of Cement", Journal of KCI, Vol. 19, No. 3, 2007, pp. 367-375.
  2. Yoon, I. S., "Analsis on Adsorption Rate & Mechanism on Chloride Adsorption Behaviour with Cement Hydrates", Journal of KCI, Vol. 27, No. 1, 2015, pp. 85-90.
  3. Neville, A., "Chloride Attack of Reinforced Concrete: An Overview", Materials and Structures, Vol. 28, No. 63, 1995, pp. 63-70. https://doi.org/10.1007/BF02473172
  4. Sanjuan, M. A., "Formation of Chloroaluminate in Calcium Aluminate Cements Cured at High Temperatures and Exposed to Chloride Solutions", Journal of Material Science, Vol. 32, No. 23, 1997, pp. 6207-6213. https://doi.org/10.1023/A:1018624824702
  5. Sumranwanich, T., "Chloride Binding Capacity of Cement-Fly Ash Paste and Simulation of Chloride Profile in Concrete", Journal of Material Science, Ph D Thesis, Sirindhorn International Institute of Technology and Thammasat University, 2004.
  6. Walcarius, A., Lefevre, G., Rapin, J. -P., Renaudin, G., and Francois, M., "Voltammetric Detection of Iodide After Accumulation by Friedel's Salt", Electroanalysis, Vol. 13, No. 4, 2001, pp. 313-320. https://doi.org/10.1002/1521-4109(200103)13:4<313::AID-ELAN313>3.0.CO;2-Q
  7. Ishida, T., Miyahara, S., and Maruya, T., "Chloride Binding Capacity of Mortars Made with Various Portland Cements and Mineral Admixtures", Journal of Advanced Concrete Technology, Vol. 6, No. 2, 2008, pp. 287-301. https://doi.org/10.3151/jact.6.287
  8. Florea, M. V. A. and Brouwers, H. J. H., "Chloride Binding Related to Hydration Products, Part I: Ordinary Portland Cement", Cement and Concrete Research, Vol. 42, 2012, pp. 282-290. https://doi.org/10.1016/j.cemconres.2011.09.016
  9. Taylor, H. F. W., Cement Chemistry, 2nd Edition, Thomas Telford, London, 1997, pp. 157-166.
  10. Paul, G., Boccaleri, E., Buzzi, L., Canonico, F., and Gataldi, D., "Friedel's Salt Formulation in Sulfoaluminsate Cements: A Combined XRD and $^{27}Al$ MAS NMR Study", Cement and Concrete Research, Vol. 67, 2015, pp. 93-102. https://doi.org/10.1016/j.cemconres.2014.08.004
  11. Glasser F. P., Kindness, A., and Stronach, S. A., "Stability and Solubility Relationships in AFm Phases: Part I. Chloride, Sulfate and Hydroxide", Cement and Concrete Research, Vol. 29, No. 5, 1999, pp. 861-866. https://doi.org/10.1016/S0008-8846(99)00055-1
  12. Suryavanshi, A. K., Scantlebury, J. D., and Lyon, S. B., "Mechanism of Friedel's Salt Formation in Cements Rich in Tri-Calcium Aluminate", Cement and Concrete Research, Vol. 26, No. 5, 1996, pp. 717-727. https://doi.org/10.1016/S0008-8846(96)85009-5
  13. Atkins, M., Glasser, F. P., and Kindness, A., "Cement hydrate phases: Solubility at $25^{\circ}C$", Cement and Concrete Research, Vol. 22, No. 2-3, 1991, pp. 241-246. https://doi.org/10.1016/0008-8846(92)90062-Z
  14. Larsson, J., "The Enrichment of Chloride in Expressed Concrete Pore Solution Submerged in Saline Solution", Proceedings of the Nordic Seminar on Field Studies of Chlorie Initiated Reinforcement Corrosion in Concrete, Lund University of Technology, Report TVBM-3064, 1995, pp. 171-176.
  15. Roberts, M. H., "Effect of Calcium Chloride on the Durability of Pretensioned Wire in Prestressed Concrete", Megazine of Concrete Research, Vol. 14, No. 42, 1962, pp. 143-154. https://doi.org/10.1680/macr.1962.14.42.143
  16. Zibara, H., "Binding of External Chloride by Cement Paste", Ph D Thesis, Department of Building Materials, University of Toronto, Canada, 2001.
  17. Rasheeduzzafur, S., Hussain, S. E., and Al-Saadoun, S. S., "Effect of Tricalcium Aluminate Content of Cement on Chloride Binding and Corrosion of Reinforcing Steel in Concrete", ACI Materials Journal, Vol. 89, No. 1, 1992, pp. 3-12.
  18. Csizmadia, J., Balazs, G., and Tamas, F. D., "Chloride Ion Binding Capacity of Tetracalcium Aluminoferrite", Periodical Polytechnica Ser. Civil Engineering, Vol. 44, No. 2, 2000, pp. 135-150.
  19. Saeki, T. and Sasaki, K., "Effect of Chemical Composition of C-S-H on Concrete Durability," International Seminar on Durability and Lifecycle Evaluation of Concrete Structures, 2006.
  20. Birnin-Yauri, U. A. and Glasser, F. P., "$Ca_2Al(OH)_6(Cl,OH){\cdot}2H_2O$: Its Solid Solutions and Their Role in Chloride Binding", Cement and Concrete Research, Vol. 28, No. 12, 1998, pp. 1713-1723. https://doi.org/10.1016/S0008-8846(98)00162-8
  21. Hirao, H., Yamada, K., Takahashi, H., and Zibara, H., "Chloride Binding of Cement Estimated by Binding Isotherms of Hydrates", Journal of Advanced Concrete Technology, Vol. 3, No. 1, 2005, pp. 77-84. https://doi.org/10.3151/jact.3.77
  22. Elakneswaran, Y., and Nawa, T., and Kurumisawa, K., "Electrokinetic Potential of Hydrated Cement in Relation to Adsorption of Chlorides", Cement and Concrete Research, Vol. 39, 2009, pp. 340-344. https://doi.org/10.1016/j.cemconres.2009.01.006
  23. Yoon, I. S., "Interaction Experiment on Chloride Ion Adsorption Behaviour of C-S-H Phases", Journal of KCI, Vol. 29, No. 1, 2017, pp. 77-84.
  24. Huang, T. and Cho, L, "Relationships between Constants of the Freundlich Equation and Temperature for Gaseous Adsorption", Chemical Engineering Communications, Vol. 75, No. 1, 1989, pp. 181-194. https://doi.org/10.1080/00986448908940676
  25. Masel, R. I., Principles of Adsorptipon and Reaction on Solid Surfaces, John Wiley & Sons, Canada, 1996.
  26. Ismadji, S., Soetaredjo, F. E., and Ayucitra, A., Clay Materials for Environmental Remediation, Springer, Switzerland, 2015.