Journal of the Korea Concrete Institute (콘크리트학회논문집)

Korea Concrete Institute (한국콘크리트학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of Mechanical Restraint due to Steel Microfibers on Alkali-Silica Reaction in Mortars

미세 강섬유의 구속력이 모르타르의 알칼리-실리카 반응에 미치는 영향

  • Yi, Chong-Ku (Dept. of Civil Environmental and Architectural Engineering, Korea University)
  • 이종구 (고려대학교 건축사회환경공학과)
  • Published : 2007.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

The effect of steel microfibers (SMF) on alkali-silica reaction (ASR) was investigated using two types of reactive aggregates, crushed opal and a pyrex rod of constant diameter. Cracks are less visible in the SMF mortars compared with the unreinforced mortars. Due to crack growth resistance behavior in SMF mortar specimens, the strength loss is eliminated and the ASR products remained well confined within the ASR site. The expansion and the ASR products were characterized by microprobe analysis and inductively coupled plasma (ICP) spectroscopy. The confinement due to SMF resulted in a higher Na and Si ion concentration of the ASR liquid extracted from the reaction site. The higher concentration reduced the ASR rate and resulted in a lower reactivity of the reactive pyrex rods in SMF mortars.

Steel microfiber (SMF)가 알칼리-실리카 반응 (ASR)에 미치는 영향을 두 가지 종류 (부순 오팔과 직경이 일정한 pyrex 막대)의 반응 골재를 사용하여 알아보았다. ASR에 의한 균열은 기준 모르타르에서 쉽게 발견되었으나 SMF 모르타르의 균열은 아주 제한적이었다. SMF의 균열 진전 제어 메커니즘을 통하여 ASR에 의한 모르타르의 강도 저하와 팽창을 효과적으로 막을 수 있었고, ASR 생성물들의 유동성이 저하됨을 알 수 있었다. ASR 생성물의 성분을 microprobe 분석과 ICP 분광계를 이용하여 알아보았다. SMF의 구속 효과는 액체상태인 ASR 생성물의 높은 나트륨이 온과 규소이온의 농도를 초래하였으며, 높은 이온의 농도는 ASR 알칼리-실리카 반응성을 저하하는 원인으로 생각되어 진다.

Keywords

References

  1. 홍승호, 한승환, 윤경구, '알칼리-실리카 반응에 의한 시멘트 콘크리트 포장 파손 사례', 콘크리트학회 논문집, 18권 3호, 2006, pp.355-360 https://doi.org/10.4334/JKCI.2006.18.3.355
  2. Clayton, N., 'The Effects of Alkali Silica Reaction on the Strength of Prestressed Concrete Beams', Struct. Engr., Vol.68, 1990, pp.287-292
  3. McGown, J. K. and Vivian, H. E., 'Studies in Cement-Aggregate Reaction, XXIII: The Effect of Superincumbent Load on Mortar Bar Expansion', Aust. J. Appl. Sci., Vol.5, 1954, pp.94-97
  4. Yamura, K., 'Effect of Steel Reinforcement on Alkali Silica Reaction of Concrete', J. Soc. Mater. Sci. Jpn., Vol.43, 1994, pp.970-975 https://doi.org/10.2472/jsms.43.970
  5. Koyanagi, W., 'Characteristics and Simulation of Concrete Cracks Caused by AAR', Proceedings of the 8th International Conference on Alkali Aggregate Reaction, Kyoto, 1989, pp.845-850
  6. Ahmed, T., Burley, E., and Rigden, S., 'Effect of Alkali-Silica Reaction on Bearing Capacity of Plain and Reinforced Concrete', ACI Mater. J., Vol.96, 1999, pp.557-570
  7. Aquino, W., Lange., D. A., and Olek, J., 'The Influence of Mtakaolin and Silica Fume on the Chemistry of Alkali-Silica Reaction Products', Cem. Concr. Compos. Vol.23, 2001, pp.485-493 https://doi.org/10.1016/S0958-9465(00)00096-2
  8. Sprung, S. and Adadian, M., 'The Effect of Admixtures on Alkali-Aggregate Reaction in Concrete', Proceedings, Symposium on Effect of Alkalis on the Properties of Concrete, London, Sept., Cement and Concrete Association, Wexham Springs, Slough, 1976, pp.125-137
  9. Oberholster, R. E. and Roy, D. M., 'The Effectiveness of Mineral Admixtures in Reducing Expansion due to the Alkali-Aggregate Reaction with Malmesbury Group Aggregates', Proceedings of the 5th International Conference on Alkali-Aggregate Reaction in Concrete, Cape Town, National Building Research Institute, Pretoria, 1981, Article S252/31
  10. Juenger, M. C. G. and Ostertag, C. P., 'Alkali-Silica Reactivity of Large Silica Fume-Derived Particles', Cem. Concr. Res., Vol.34, No.8, 2004, pp.1389-1402 https://doi.org/10.1016/j.cemconres.2004.01.001
  11. MacCoy, E. J. and Caldwell, A. G., 'New Approach to Inhibiting Alkali-Aggregate Expansion', J. Am. Concr. Inst., Vol.22, 1951, pp.693-706
  12. Diamond, S. and Ong, S., 'The Mechanisms of Lithium Effects on ASR', Proceedings of the 9th International Conference on Alkali Aggregate Reaction, Concrete Society of UK, London, 1992, pp.269-278
  13. Hobbs, D. W., 'Deleterious Expansion of Concrete due to Alkali-Silica Reaction: Influence of PFA and Slag', Magn. Concr. Res., Vol.36, 1986, pp.191-205
  14. Diamond, S., 'Alkali Silica Reaction-Some Paradoxes', Cem. Concr. Compos., Vol.19, 1997, pp.391-401 https://doi.org/10.1016/S0958-9465(97)00004-8
  15. St. John, D. A. and Freitag, S. A., 'Fifty Years of Investigation and Control of AAR in New Zealand', Alkali-Aggregate Reaction in Concrete, Proceedings of the 10th International Conference, Melbourne, 1996, pp.150-157
  16. Kawamura, M. and Fuwa, H., 'Effect of Lithium Salts on ASR Gel Composition and Expansion of Mortars', Cem. Concr. Res., Vol.33, 2003, pp.913-919 https://doi.org/10.1016/S0008-8846(02)01092-X
  17. Yi, C. K. and Ostertag, C. P., 'Strengthening and Toughening Mechanisms in Microfiber Reinforced Cementitious Composites', J. Mater. Sci., Vol. 36, 2001, pp.1513-1522 https://doi.org/10.1023/A:1017557015523
  18. ASTM C 1260-94, Standard Test Method for Potential Alkali Reactivity of Aggregates (Mortar-Bar Method), Annual Book of ASTM Strandards v.04.02, Concrete and Aggregates, American Society for Testing and Materials, Philadelphia, 1999, pp.650-653
  19. Turanli, L., Shomglin, K., Ostertag, C. P., and Monteiro, P. J. M., 'Reduction in Alkali-Silica Expansion due to Steel Microfibers', Cem. Concr. Res., Vol.31, 2001, pp.827-835 https://doi.org/10.1016/S0008-8846(00)00441-5
  20. Ostertag, C. P. and Yi, C. K., 'Quasi-Brittle Behavior of Cementitious Matrix Composites', Mater. Sci. Eng. A, Vol.278, 2000, pp.95-98
  21. Powers, T. C. and Steinmour, H. H., 'Part I-The Chemical Reactions and Mechanisms of Expansion', ACI J., Vol.26, 1955, pp.497-515
  22. Bleszynski, R. F. and Thomas, M. D. A., 'Microstructural Studies of Alkali-Silica Reaction in Fly Ash Concrete Immersed in Alkaline Solution', Adv. Cem. Based Mater., Vol.7, 1998, pp.66-78 https://doi.org/10.1016/S1065-7355(97)00030-8
  23. Durand, B., Berard, J., and Roux, R., Soles, J. A. 'Alkali-Silica Reaction: the Relation between Pore Solution Characteristics and Expansion Test Results', Cem. Concr. Res., Vol.20, 1990, pp.419-328 https://doi.org/10.1016/0008-8846(90)90032-S
  24. Sposito, G., The Surface Chemistry of Soils, Oxford University Press, New York, 1984
  25. Prezzi, M., Monteiro, P. J. M., and Sposito, G., 'The Alkali-Silica Reaction, Part I: Use of the Double-Layer Theory to Explain the Behavior of Reaction-Product Gels', ACI Mat. J., Vol.94, No.1, 1997, pp.10-17