KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
권호 표지
DOI QR코드

DOI QR Code

Long-term Durability Characteristics of Fly ash Concrete Containing Lightly Burnt MgO Powder

저온 소성한 MgO 분말을 함유한 플라이애시 콘크리트의 장기재령에서의 내구특성

  • 장봉석 (한국수자원공사 K-water연구원) ;
  • 최슬우 (성균관대학교 건설환경시스템공학과) ;
  • 이광명 (성균관대학교 건설환경시스템공학과)
  • Received : 2013.01.23
  • Accepted : 2013.03.07
  • Published : 2013.05.30
Download PDF
⟨ Previous Next ⟩

Abstract

Concrete containing lightly burnt MgO has long term expansibility. It also could compensate for the thermal shrinkage of mass concrete, because the hydration of MgO proceeds at a slow pace to long-term age. Thus, lightly burnt MgO has been applied to the construction of mass concrete such as dams. Recently, the expansion characteristics of MgO concrete with fly ash that could be applied to mass concrete for the reduction of hydration heat have been studied and however, limited studies on its durability. This study investigates the long-term durability characteristics of fly ash concrete with lightly burnt MgO. The durability tests on carbonation, freezing-thawing, diffusion of chloride, and resistance to sulfate attack were carried out for MgO concrete with curing for 360 days in submerged condition with different temperature of 20 and $50^{\circ}C$. The results reveal that MgO concrete shows a greater resistance of carbonation, diffusion of chloride, and resistance to sulfate attack. On the other hand the resistance of freezing-thawing was little influenced by MgO powder.

저온에서 소성된 산화마그네슘 분말을 치환한 MgO 콘크리트는 장기적인 팽창성을 가진다. 또한 MgO의 수화반응이 느린 속도로 장기재령까지 일어나기 때문에 매스콘크리트의 온도수축을 효과적으로 보상할 수 있다. 따라서 저온 소성한 MgO는 매스콘크리트 구조물인 댐에 주로 적용되었다. 최근 수화열 저감을 위해 매스콘크리트에 많이 사용되는 플라이애시를 사용한 MgO 콘크리트의 팽창특성에 대한 연구가 진행되어 왔지만 이러한 콘크리트의 내구성에 관한 연구는 부족한 실정이다. 이 연구에서는 플라이애시 콘크리트에 저온 소성한 MgO 분말을 치환하여 MgO 분말 치환에 따른 장기재령에서의 내구특성을 확인하였다. 재령 360일까지 20, $50^{\circ}C$에서 수중 양생을 실시한 후 탄산화, 동결융해 및 염화물 확산, 황산염 침투 저항성을 평가하였다. 실험결과, MgO 분말을 치환한 시편에서 탄산화 저항성 및 염해 저항성, 황산염 침투 저항성이 다소 향상되는 것을 확인하였다. 반면 동결융해 저항성은 MgO 분말 치환에 거의 영향을 받지 않았다.

Keywords

References

  1. Amaral, L. F., Oliveira, I. R., Salomao, R., Frollini, E., Randolfelli, V. C. (2010). "Temperature and common-ion effect on magnesium oxide (MgO) hydration." Ceramics International, Vol. 36, No. 3, pp. 1047-1054. https://doi.org/10.1016/j.ceramint.2009.12.009
  2. Bae, S. H., Park, J. I., Lee, K. M. (2010). "Influence of mineral admixture on the resistance to sulfuric acid and sulfate attack in concrete." Journal of the Korea Concrete Institute, Vol. 22, No. 2, pp. 219-228 (in Korean). https://doi.org/10.4334/JKCI.2010.22.2.219
  3. Choi, S., Lee, K. M., Jung, S. H., Kim, J. H. (2009). "A study on the carbonation characteristics of fly ash concrete by accelerated carbonation test." Journal of the Korea Concrete Institute, Vol. 21, No. 4, pp. 449-455 (in Korean). https://doi.org/10.4334/JKCI.2009.21.4.449
  4. Choi, S. W., Kim, J. H., Lee, K. M., Kwon, Y. G., Jang, B. S. (2011). "Durability characteristics of concrete containing lightly burnt MgO powder." Journal of the Korea Concrete Institute, Vol. 23, No. 5, pp. 609-615 (in Korean). https://doi.org/10.4334/JKCI.2011.23.5.609
  5. Du, C. (2005). "A Review of magnesium oxide in concrete." Concrete International, Vol. 27, No. 12, pp. 45-50.
  6. Gao, P., Wu, S., Lu, X., Deng, M., Lin, P., Wu, Z., Tang, M. (2007). "Soundness evaluation of concrete with MgO." Construction and Building Materials 21, Vol. 21, No. 1, pp. 132-138. https://doi.org/10.1016/j.conbuildmat.2005.06.033
  7. Gao, P., Geng, F., Hou, J., Li, X., Lin, H., Lu, X., Shi, N. (2008). "Production of MgO-type expansive agent in dam concrete by use of industrial by-products." Building and Environment. Vol. 43, No. 4, pp. 453-457. https://doi.org/10.1016/j.buildenv.2007.01.037
  8. Jang, B. S., Kwon, Y. G., Choi, S. W., Lee. K. M. (2011). "Fundermental peoperties of cement composites containing lightly burnt MgO powders." Journal of the Korea Concrete Institute, Vol. 23, No. 2, pp. 225-233 (in Korean). https://doi.org/10.4334/JKCI.2011.23.2.225
  9. Kim, J. K., Moon, Y. H., Eo, S. H., Choi, E. K. (1998). "The effect of different curing time and temperature on compressive strength of concrete." Journal of the Korea Concrete Institute, Vol. 10, No.3, pp. 143-152 (in Korean).
  10. Kim, J. K., Park, Y. D., Sung, K. Y. (1991). "The long-term strength and the workability of high-strength fly ash concrete." Journal of the Korea Concrete Institute, Vol. 3, No. 4, pp. 107-115 (in Korean).
  11. Kim, N. W., Yeo, D. G., Song, J. J., Bae, J. S. (2007). "A study on the characteristic of capillary pore and chloride diffusivity by electrical difference of high-strength concrete using metakaolin." Journal of the Korea Concrete Institute, Vol. 19, No. 4, pp. 499- 506 (in Korean). https://doi.org/10.4334/JKCI.2007.19.4.499
  12. Lee, C. Y., Choi, S. H., Kang, S. H., Lee, K. M. (1999). "Influence of fly ash content with respect to the fresh and mechanical properties in concrete." Journal of the Korea Concrete Institute, Vol. 11, No. 6, pp. 25-33 (in Korean).
  13. Li, C. M. (1997). "Effect of fly ashes on deformation and mechanic properties of MgO concrete." Study on Hydroelectric Engineering, pp. 1-9 (in Chinese).
  14. Li, C.M. (1998). "Long-term self-volume deformation of concrete with MgO." Hydro power Generation, pp. 53-57 (in Chinese).
  15. Lingling, X., Deng, M. (2005) "Dolomite used as raw material to produce MgO-based expansive agent." Cement and Concrete Research, Vol. 35, No. 8, pp. 1480-1485. https://doi.org/10.1016/j.cemconres.2004.09.026
  16. Liu Z., Cui X., Tang M. (1991). "MgO-type delayed expansive cement." Cement and Concrete Research, Vol. 21, No. 6, pp. 1049-1057. https://doi.org/10.1016/0008-8846(91)90065-P
  17. Mo, L., Deng, M., Tang, M. (2010). "Effects of calcination condition on expansion property of MgO-type expansive agent used in cement-based materials." Cement and Concrete Research, Vol. 40, No. 3, pp. 437-446. https://doi.org/10.1016/j.cemconres.2009.09.025
  18. Mo, L., Panesar, D. K. (2012). "Effects of accelerated carbonation on the microstructure of Portland cement pastes containing reactive MgO." Cement and Concrete Research, Vol. 42, No. 6, pp. 769-777. https://doi.org/10.1016/j.cemconres.2012.02.017
  19. Naik, T. R., Singh, S. S., Hossain, M. M. (1994). "Permeability of concrete containing large amount of fly ash." Cement and concrete research, Vol. 24, No. 5, 1994, pp. 913-922. https://doi.org/10.1016/0008-8846(94)90011-6
  20. Oh, B. H., Jung, S. H., Lee, M. K. (2003). "Influence of porosity on the CO2 diffusion characteristic in concrete." Journal of the Korea Concrete Institute, Vol. 15, No. 3, pp. 443-453 (in Korean). https://doi.org/10.4334/JKCI.2003.15.3.443
  21. Salomao, R., Bittencourt L. R. M., Pandolfelli, V. C. (2007). "A novel approach for magnesia hydration assessment in refractory castables." Ceramics International, Vol. 33, No. 5, pp. 803-810. https://doi.org/10.1016/j.ceramint.2006.01.004
  22. Yoon, E.S., Lee, T. W., Park, S. B. (2005). "Analysis of correlation between compressive strength, void ratio and chloride diffusion coefficient of concrete using various kinds of cement." Journal of the Korea Concrete Institute, Vol. 17, No. 5, pp. 735-742 (in Korean). https://doi.org/10.4334/JKCI.2005.17.5.735