Journal of the Korean Society of Hazard Mitigation (한국방재학회 논문집)

Korean Society of Hazard Mitigation (한국방재학회)
권호 표지
DOI QR코드

DOI QR Code

Prediction of Service Life for Marine Concrete Structures by Exposure Experiments

폭로실험에 의한 해양콘크리트 구조물의 내구적 수명예측

  • 이창수 (서울시립대학교 토목공학과) ;
  • 김명원 (한국농어촌공사 농어촌연구원)
  • Received : 2014.03.27
  • Accepted : 2014.04.23
  • Published : 2014.06.30
⟨ Previous Next ⟩

Abstract

In this study, based on the theory, a basic model for predicting salt damage was made in the laboratory experiment, and a maintenance simulation system was developed by constructing a numerical model using the basic model. The basic model was modified through data trends by periodically analyzing the specimens, which were exposed to marine environment for a long period of time, following the experimental plan. The chloride content distribution of 6 marine concrete structures, which were completed about 30 years ago, was analyzed to test the model. In the basic model equation for predicting chloride, the surface chloride content was modified to be ${\alpha}$ times the surface chloride concentration, reflecting the research which suggested that the chloride concentration in concrete could gradually increase under dry-wet cycling due to the effect of evapotranspiration within the pores. The data predicted from the modified model was compared with the field data, and by estimating the timing of threshold chloride content (i.e., repair time), it was suggested that the model and maintenance system proposed in this paper can be used to predict the service life.

연구는 실내실험에서 이와 같은 이론을 토대로 염해예측 기본모델을 만들고 해양환경에 장기간 폭로된 실험체를 실험계획에 따라 주기적으로 분석하여 데이터 추이를 통해 기본모델을 수정하였다. 모델 검증을 위해 준공 후 약 30년 경과된 6개의 해양콘크리트 구조물의 염화물함량 분포를 분석하였다. 염화물 예측 기본 모델식에서 표면염화물함량은 콘크리트 내의 염화물 농도가 건습이 반복 될수록 공극내 증발산의 영향으로 점차 높아 질수 있음을 제시한 연구사례를 반영하여 표면염화물 농도의 ${\alpha}$ 배로 수정하였다. 수정된 모델을 통하여 예측한 데이터와 현장데이터를 비교하였으며, 임계염화물함량 도출시점, 즉 보수시점을 추정함으로써 내구수명 예측에 이용될 수 있도록 하였다.

Keywords

Acknowledgement

Supported by : 서울시립대학교

References

  1. Bae Y.J. (2012) A Study on the Application of Marine Concrete using Ternary Blended Cement considering Chloride Attack and Hydration Heat, Civil Engineering, Ph.D Study, Chungnam National University, Daejeon, Korea pp. 21.
  2. Bamforth, P.B. and Price, W.F. (1997) An International Review of Chloride Ingress into Structural Concrete, Report no 303/969092, Taywood Engineering LTD. Technology Division.
  3. Kwon, S.J. Park, S.S., and Na, U.J. (2007) Service Life Prediction based on Stochastic Approach for Cracked Concrete Structures exposed to Chloride attack, Journal of KSCE, Vol. 27, No. 6A, pp. 881-890. (in korean)
  4. Lee, C.S. and Kim, M.W. (2013) Development of Maintenance Simulation System and Prediction of Chloride Ion Permeationfor Marine Concrete Structures, Journal of KSMI, Vol. 17, No. 1, pp. 64-75. (in korean)
  5. Magne Maage, Steinar Helland and Jan Erik Carlsen (1995) Practical Non-Steady State Chloride Transport as a Part of a Model for Predicting the Initiation Period, Proceeding Interational RILEM Workshop: Chloride Penetration into Concrete, Oct. 15-18, Saintremy-Les-Chevreuse, pp. 398-406.
  6. Magne Maage, Steinar Helland, Ervin Poulsen, Oystein Ven-nesland and Jan Erik Carlsen (1996) Service Life Prediction of Existing Concrete Structures Exposed to Marine Environment, ACI Materials Journal, Vol. 93, No. 6, pp. 602-608.
  7. Takeda, N., Sogo, S. Sakoda, S., and Idemitu, T. (1998) An Experimental Study on Penetration of Chloride Ions into Concrete and Corrosion of Reinforcing Bars in Various Marine Environments, Journal of JSCE, Vol. 40, No. 599, pp. 91-104.
  8. Zhang, Y. and Jin, W.-L. (2011) Distribution of Chloride Accumulation in Marine Tidal Zone along Altitude. ACI Materials Journal, Vol. 108, No. 5, pp. 1-9.