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Concrete Temperature History and Micropore by using Insulation Gang-Form in -20℃ Cold Weather Conditions

-20℃ 혹한기 조건에서 단열갱폼 사용에 따른 콘크리트 온도이력 및 미세공극 특성

  • Received : 2015.09.23
  • Accepted : 2016.01.19
  • Published : 2016.01.30

Abstract

This paper is about a test performed to concrete form work in $-20^{\circ}C$ cold weather conditions on climate change by global warming Furthermore, this paper examines limitations in application insulation gang form and analysis temperature history, strength development and characteristic of micropore of concrete placed in abnormal winter weather. According to the test result, concrete temperature dropped below $0^{\circ}C$ in the case of general gang form 12 hours after concrete placement. However, we could find excellent insulating effect rather than general gang form in the case of insulation gang form because temperature of outer surface and core of concrete has not dropped below $7^{\circ}C$ and highest temperatures was recorded $8{\sim}10^{\circ}C$ within 12 hours despite drastic ambient temperature conditions after concrete placing. In comparison of temperature record of surface portion of insulation gang form and that with or without wales by temperature record of insulation weak point, with wales is not as good as that on surface portion of insulation gang form. The reason for this is thought to be the decline in hydration reaction of concrete due to the decreases of ambient temperature and lack of insulation effect by wale protection made of pvc. As concrete got aged, the number of micropores less than $1{\mu}m$ has increased and it of the large voids has decreased. Also, more small pore were observed in concrete placed with insulation gang form than with general gang form.

Keywords

Acknowledgement

Supported by : 중소기업청

References

  1. Han, C. G., & Han, M. C. (2000). Determination of the Protecting Periods of Frost Damage at Early Age in Cold Weather Concreting, Journal of the Concrete Institute of Korea, 12(3), 47-55.
  2. Jung, S. J., Nam, K. Y., Kang, I. S., Lee, J. K., Lee, Y. D., & Won, J. Y. (2011). Characteristics of Temperature Record in Concrete According to the use of Gang Form with Application of Polyurethane Form to Cold Climate, Journal of the Architectural Institute of Korea, Structure & Construction, 27(10), 189-196.
  3. Kim, K. M., Won, C., Lee, H. J., Oh, S. K., & Han, C. G. (2001). A Fundamental Study on the Development of Insulating Forms for Cold Weather Concreting, Spring proceedings of the Architectural Institute of Korea in Structure & Construction Section, 21(1), 293-296.
  4. Korea Concrete Institute. (2009). Concrete Standard Specification.
  5. Kim, K. M., Son, S. U., Kim, G. C., Oh, S. K., & Han, C. G. (2002). A Fundamental Study on the Efficiency of Cold Weather Concreting Using Insulating Form(Focused on the Joint), Spring proceedings of the Architectural Institute of Korea in Structure & Construction Section, 22(1), 301-304.
  6. Nam, K. Y., Ha, J. S., Won, J. Y., Paik, M. S., Lim, N. G., & Jung, S. J. (2011a). A Study on the Evaluation of the Applicability of the Insulation Gang Form for Winter Construction, Spring proceedings of the Architectural Institute of Korea in Structure & Construction Section, 32(1), 141-142.
  7. Nam, K. Y., Choi, W. I., Seo, Y. A., Kim, S. D., Won, J. Y., & Jung, S. J. (2011b). An Experimental Study on the Temperature and Strength Development of the Concrete Using Insulation Gang Form, Spring proceedings of the Concrete Institute of Korea, 23(2), 763-764.
  8. Nam, K. Y., Won, J. Y., Chun, J. Y., & Jung, S. J. (2012). Temperature Record and Strength Development from Using Gang Form Adhered to Polyisocyanurate Board, Journal of the Architectural Institute of Korea, Structure & Construction, 28(7), 117-124. https://doi.org/10.5659/JAIK_SC.2012.28.7.117
  9. Nam, K. Y., Won, J. Y., Kang, I. S., Jeon, P. K., Lee, Y. D., & Jung, S. J. (2011c). A Study on Thermal Properties of Concrete Using Gang Form Coates with Polyurethane, Spring proceedings of the Korea Institute of Building Construction, 11(1), 11-12.
  10. Mehta, P. K. (1973). Concrete, structure, properties and materials, Prentice Hall, 25.
  11. Roh, D. S. (2008). Apartment formwork Guide, LH.
  12. Won, J. Y. (2012). Study on Concrete Curing Performance of Insulation Gang Form Applied Urethane Foam, Dankook University, Dissertation.