한국구조물진단유지관리공학회 논문집 (Journal of the Korea institute for structural maintenance and inspection)

  • 제23권7호
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  • Pages.72-79
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  • 2019
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  • 2234-6937(pISSN)
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  • 2287-6979(eISSN)
한국구조물진단유지관리공학회 (Korea Institute for Structural Maintenance Inspection)
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알파형 반수석고를 활용한 콘크리트의 역학적 특성

Mechanical Properties of Concrete using Alpha-Calcium Sulfate Hemihydrate

  • 투고 : 2019.10.25
  • 심사 : 2019.11.14
  • 발행 : 2019.12.01
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초록

콘크리트는 경화 중의 온도변화나 수축에 의한 체적변화, 외부 힘의 작용, 시공불량 등에 의해 균열이 발생할 가능성이 높다. 특히, 전력구 구조물에 시공되는 콘크리트는 다양한 요인에 의해 균열이 발생되고 있어 지속적인 유지관리가 필요한 실정이다. 이에 본 연구에서는 산업부산물로서 팽창성능이 있는 알파형 반수석고를 활용한 콘크리트의 역학적 특성에 대해 검토하였다. 기존 연구결과를 바탕으로 알파형 반수석고를 치환시 압축강도가 감소하는 점을 보완하기 위하여 시멘트의 사용량은 동일하게 고정한 후 알파형 반수석고를 9% 첨가하고, 혼화제의 사용량을 조절한 후 콘크리트의 역학적 특성을 평가하였다. 실험 결과, 콘크리트의 압축강도가 OPC와 동등이상의 수준으로 나타났으며, 알파형 반수석고를 9% 첨가시 OPC 대비 약 30% 이상의 수축이 저감되어 콘크리트의 균열 저감에 효과가 있을 것으로 판단된다.

Concrete is vulnerable to cracks due to volume changes caused by temperature changes, shrinkage during curing, external forces, or poor construction. In particular, concrete placed in electric power tunnel structures can generate cracks by a variety of factors. As a result, these tunnel structures require continuous maintenance. In this study, we investigated the mechanical properties of electric power tunnel concrete using alpha-calcium sulfate hemihydrate, which is an industrial byproduct that has excellent expansion performance. To compensate for the decrease in compressive strength when substituting alpha-calcium sulfate hemihydrate, based on previous research, we added 9% alpha-calcium sulfate hemihydrate and adjusted the amount of admixture while using the same amount of cement. We then evaluated the mechanical properties of the concrete. The results showed that the compressive strength of the concrete was higher than that of ordinary Portland cement (OPC), and the shrinkage of concrete was reduced by more than 30% compared to that of OPC. Therefore, adding 9% of alpha-calcium sulfate hemihydrate is expected to have a significant effect in reducing concrete cracks.

키워드

참고문헌

  1. Lee, D. G., Han, S. H., Jeong Y. K. (2016), Chemical admixture technology for reducing shrinkage of concrete, Magazine of the Korea Concrete Institute, 28(6), 31-36.
  2. Woo, S. K., Kim, K. J., Lee, Y. (2016), Reduction of drying shrinkage cracking of box culvert for power transmission with shrinkage reducing agent. Journal of the Korea Institute for Structural Maintenance and Inspection, 20(5), 102-108. https://doi.org/10.11112/jksmi.2016.20.5.102
  3. Woo, S. K., Chu, I. Y., Kim, K. J., Lee, Y. (2016), Cracking behavior of concrete box culvert for power transmission due to drying shrinkage. Journal of the Korea Institute for Structural Maintenance and Inspection, 20(1), 1-8. https://doi.org/10.11112/jksmi.2016.20.1.001
  4. Shin, K. S., Kim, G. Y., Sung, G. M., Woo, S. K., Chu, I. Y., Lee, B. K. (2019), Mechanical properties of alpha-calcium sulfate hemihydrate replaced concrete for application to box culvert power transmission, Journal of the Korea Institute of Building Construction, 19(1), 1-7. https://doi.org/10.5345/JKIBC.2019.19.1.001
  5. Chu, I. Y., Woo, S. K., Lee, B. J. (2018), Physical properties of self-healing concrete mixed with hydrogel carrier of microorganism, Journal of the Korea Institute for Structural Maintenance and Inspection, 22(6), 24-29. https://doi.org/10.11112/JKSMI.2018.22.6.024
  6. Lee, K. H., Kim, G. Y., Lee, B. K., Shin, K. S., Nam, J. S. (2017), Setting Time, compressive strength and drying shrinkage of mortar with alpha-calcium sulfate hemihydrate, Journal of the Korea Institute for Structural Maintenance and Inspection, 21(5), 117-124. https://doi.org/10.11112/jksmi.2017.21.5.117
  7. Jiang, G., Wang, H., Chen, Q., Zhang, X., Wu, Z., and Guan, B. (2016), Preparation of alpha-calcium sulfate hemihydrate from FGD gypsum in chloride-free $Ca(NO_3)_2$ solution under mild conditions, Fuel, 174,235-241. https://doi.org/10.1016/j.fuel.2016.01.073
  8. Guan, B., Yang, L., Fu, H., Kong, B., Li, T., and Yang, L. (2011), ${\alpha}$-calcium sulfate hemihydrate preparation from FGD gypsum in recycling mixed salt solutions, Chemical Engineering Journal, 174(1), 296-303. https://doi.org/10.1016/j.cej.2011.09.033
  9. Kim, T. W., Hahm, H. G. (2012), Mechanical properties of the alkali-activated slag mortar with gypsum, Journal of the Korea Institute for Structural Maintenance and Inspection, 16(3), 109-116. https://doi.org/10.11112/jksmi.2012.16.3.109
  10. Kim, T. W., Hahm, H. G. (2012), Mechanical properties of the alkali-activated slag mortar with gypsum, Journal of the Korea Institute for Structural Maintenance and Inspection, 16(3), 109-116. https://doi.org/10.11112/jksmi.2012.16.3.109
  11. Lee, B. K., Kim, G. Y., Nam, J. S., Lee, K. H., Kim, G. T., Lee, S. K., Shin, K. S., Koyama, T. (2019), Influence of ${\alpha}$-calcium sulfate hemihydrate on setting, compressive strength, and shrinkage strain of cement mortar, Materials, 12(1), 163. https://doi.org/10.3390/ma12010163
  12. Lee, S. H., Kim, H. J., Lim, Y. J., Kim, D. H., Park, B. S. (2019), Effect of $Na_2SO_4$ on autogenous healing in initial cracking of blast furnace slag cement paste, Journal of the Korea Concrete Institute, 31(3), 261-267. https://doi.org/10.4334/JKCI.2019.31.3.261
  13. Lee, S. H., Lee, G. H., Yoo, D. W., Ha, J. H., Cho, Y. G. (2015), Hydration and insulation characteristics of a ground granulated blast furnace slag based non-sintered cement using circulating fluidized bed combustion ash as a activator, Journal of the Korea Concrete Institute, 27(3), 244-251.