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A Study on the Determination of Setting Time of Concrete in the Determination of Slip-up Speed for Slip-Form System

슬립폼 시스템 상승속도 결정에 요구되는 콘크리트에서의 초기경화시간 결정을 위한 연구

  • 김희석 (한국건설기술연구원 구조교량연구실) ;
  • 김영진 (한국건설기술연구원) ;
  • 진원종 (한국건설기술연구원 구조교량연구실)
  • Received : 2011.01.06
  • Accepted : 2011.04.29
  • Published : 2011.08.31

Abstract

The setting time which is the important element for the determination of slip-up speed of Slip-Form system is the hardening time of early-age concrete when the in place concrete has minimum compressive strength before the concrete appears out of Slip-Form system. But it is very difficult to predict the setting time because it depends on not only the composition ratio of concrete but also various conditions of construction fields. Thus, the technique to estimate accurately and continuously the hardening time of early-age in place concrete during operating Slip-Form system is necessary to guarantee the safety of Slip-Form system and the maintenance of the shape of concrete. Ultrasonic wave-based nondestructive testing methods have the advantages which are accurate and continuous in estimating concrete compressive strength. Of such methods, the method using surface wave which propagates along the surface of material is effective for thick member such as a pylon. Thus, in this paper a study on the determination of slip-up speed for Slip-Form system using surface wave velocity is performed. The relation between the slip-up speed of Slip-Form system and the setting time is formulated, and the surface wave velocity is estimated from continuous wavelet transform of the numerical results for surface wave propagation. Finally, the accuracy of this method according to the distance between the wave source and receivers and the relation between the estimated surface wave velocity and the elastic modulus are investigated.

Acknowledgement

Grant : 콘크리트 고주탑 가설장비 및 공법개발

References

  1. 건설교통부(2006) 가설공사표준시방서, 건설교통부
  2. 국토해양부(2009) 콘크리트표준시방서, 국토해양부
  3. 김희석, 이종세(2007) 파진행 문제를 위한 Paraxial 경계조건의 유한요소해석, 한국전산구조공학회논문집, 한국전산구조공학회, 제20권 제3호, pp. 303-309.
  4. 이회근, 이광명(2002) 초음파 속도 모니터링에 의한 고강도 콘크 리트의 응결 평가, Journal of the Korea Concrete Institute, Vol. 14, No. 6, pp. 973-981. https://doi.org/10.4334/JKCI.2002.14.6.973
  5. 천재원, 이영철(1997) 서해대교현장 슬립폼공법 시험시공(Mockup Test), 대림기술정보, '97 여름, pp. 99-107.
  6. 최병선(2005) Wavelet해석, 세경사.
  7. 한국콘크리트학회(2002) 콘크리트 건설 제요령, 한국콘크리트학회.
  8. ACI Commitee 318 (2004) Building Code Requirements for Structural Concrete and Commentary, ACI 318.
  9. Bedford, A. and Drumheller, D.S. (1996) Elastic wave propagation, John Wiley & Sons Ltd. New York.
  10. Graff, K.F. (1975) Wave motion in elastic solids, Ohio State University Press.
  11. Hurd, M.K. (2005) Formwork for Concrete, ACI 347.
  12. Pauw, A. (1960) Static modulus of elasticity of concrete as affected by density, Proceedings, ACI Journal, Vol. 57, No. 6, pp. 679-687.
  13. Reddy, J.N. (2006) An introduction to the finite element method, McGraw-Hill, New York.
  14. Shin, S.W., Yun, C.B., opovics, J.S., and Kim, J.H. (2007) Improved Rayleigh wave velocity measurement for nondestructive earlyage concrete monitoring, Research in Nondestructive Evaluation, American Society for Nondestructive Testing, 18, pp. 45-68.
  15. Viktorov, I.A. (1967) Rayleigh and Lamb waves, Physical theory and applications, Plenum Press, New York.
  16. Woods, R.D. (1968) Screening of surface waves in soils, J. Soil Mech. Founds Div., ASCE, July 94, pp. 951-79.