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Probabilistic Analysis of Repairing Cost Considering Random Variables of Durability Design Parameters for Chloride Attack

염해-내구성 설계 변수에 변동성에 따른 확률론적 보수비용 산정 분석

  • 이한승 (한양대학교 건축공학과) ;
  • 권성준 (한남대학교 건설시스템 공학과)
  • Received : 2017.05.31
  • Accepted : 2017.10.31
  • Published : 2018.01.01

Abstract

Repairing timing and the extended service life with repairing are very important for cost estimation during operation. Conventionally used model for repair cost shows a step-shaped cost elevation without consideration of variability of extended service life due to repairing. In the work, RC(Reinforced Concrete) Column is considered for probabilistic evaluation of repairing number and cost. Two mix proportions are prepared and chloride behavior is evaluated with quantitative exterior conditions. The repairing frequency and cost are investigated with varying service life and the extended service life with repairing which were derived from the chloride behavior analysis. The effect of COV(Coefficient of Variation) on repairing frequency is small but the 1st repairing timing is shown to be major parameter. The probabilistic model for repairing cost is capable of reducing the number of repairing with changing the intended service life unlike deterministic model of repairing cost since it can provide continuous repair cost with time.

염해에 따라 발생하는 보수시기와 보수로 유지되는 내구수명은 보수비용 평가에 매우 중요한 요소이다. 일반적으로 사용하는 결정론적 보수비용 평가는 사용기간의 연장에 따라 계단식으로 증가하게 되며, 보수로 인해 변동되는 내구수명의 변화를 고려하지 못한다. 본 연구에서는 확률론적인 보수시기 및 비용을 평가하기 위해, 염해에 노출된 콘크리트 교각을 선정하였다. 두 가지 배합과 염화물에 노출된 외부 환경조건을 고려하여 염화물 거동을 평가하였으며, 도출된 내구수명과 수명에 대한 확률변수를 변화시키면서 보수시기 및 비용 변화를 분석하였다. 변동계수의 변화에 따른 보수회수는 큰 차이가 발생하지 않았으나, 초기의 내구수명 연장이 구조물의 보수시기 및 비용에 큰 영향을 미치고 있었다. 또한 확률론적 보수비용 산정 모델은 결정론적 모델과 다르게 연속적인 보수비용이 평가되므로 목표내구수명에 따라 보수회수를 감소시킬 수 있는 효과적인 기법임을 규명되었다.

Keywords

References

  1. Al-Amoudi, O. S. B., Al-Kutti, W. A., Ahmad, S., and Maslehuddin, M. (2009), Correlation between compressive strength and certain durability indices of plain and blended cement concretes, Cement and Concrete Composites, 31(9), 672-676. https://doi.org/10.1016/j.cemconcomp.2009.05.005
  2. Alonso, C., Castellote, M., and Andrade, C. (2002), Chloride Threshold Dependence of Pitting Potential of Reinforcements, Electrochemica Acta, 47(21), 3469-3481. https://doi.org/10.1016/S0013-4686(02)00283-9
  3. Barringer, H. P. and Weber, D. P. (1997), Life cycle cost & reliability for process equipment, 8th Annual Energy Week Conference and Exhibition, American Petroleum Institute, Houston, Texas, 1-22.
  4. Bian, J., Sun, X., Wang, M., Zheng, H., and Xing, H. (2014), Probabilistic Analysis of Life Cycle Cost for Power Transformer, Journal of Power and Energy Engineering, 2(4), 489-494. https://doi.org/10.4236/jpee.2014.24066
  5. Broomfield, J. P. (1997), Corrosion of Steel in Concrete: Understanding, Investigation and Repair, E&FN, London, 1-15.
  6. Chan, A., Keoleian, G., and Gabler, E. (2008), Evaluation of Life-Cycle Cost Analysis Practices Used by the Michigan Department of Transportation, Journal of Transportation Engineering, 134(6), 236-245. https://doi.org/10.1061/(ASCE)0733-947X(2008)134:6(236)
  7. EN 1911 (2000), Eurocode 1 - Basis of Design and Actions on Structures.
  8. Flintsch, G. W. and Chen, C. (2004), Soft computing applications in infrastructure management, Journal of Infrastructure Systems, 10(4), 157-166. https://doi.org/10.1061/(ASCE)1076-0342(2004)10:4(157)
  9. JSCE (2007), Standard Specification and Guidelines, Japan Society of Civil Engineers.
  10. KCI (2012), Concrete Standard Specification -Durability Part, Korea Concrete Institute.
  11. Kim, S.-J., Kim, Y.-J., and Kwon, S.-J. (2014), $CO_2$ Evaluation of Reinforced Concrete Column Exposed to Chloride Attack Considering Repair Timing, Journal of Korean Recycled Construction Resources Institute, 2(1), 1-9. https://doi.org/10.14190/JRCR.2014.2.1.001
  12. Kwon, S.-J. and Na, U. J. (2011), Prediction of curability for RC column with crack and joint under carbonation based on probabilistic approach, International Journal of Concrete Structures and Materials, 5(1), 11-18. https://doi.org/10.4334/IJCSM.2011.5.1.011
  13. Kwon, S.-J., Na, U. J., Park, S. S., and Jung, S. H. (2009), Service life prediction of concrete wharves with early-aged crack: Probabilistic approach for chloride diffusion, Structural Safety, 31(1), 75-83. https://doi.org/10.1016/j.strusafe.2008.03.004
  14. Lee, S. H. and Kwon, S. J. (2012), Experimental study on the relationship between time-dependent chloride diffusion coefficient and compressive strength, Journal of the Korea Concrete Institute, 24(6), 715-726. https://doi.org/10.4334/JKCI.2012.24.6.715
  15. Martinez, L. H. (2001), A neuro-fuzzy decision support system for risk analysis of revenue-dependent infrastructure projects, Ph.D. dissertation, West Lafayette, Purdue University, Department of Civil Engineering.
  16. Mulubrhan, F., Mokhtar, A. A., and Muhammad, M. (2014), Integrating Reliability Analysis in Life Cycle Cost Estimation of Heat Exchanger and Pump, Advanced Materials Research, 903, 408-413. https://doi.org/10.4028/www.scientific.net/AMR.903.408
  17. Nasir, M., Chong, H. Y., and Osman, S. (2015), Probabilistic Life Cycle Cost Model for Repairable System, IOP Conference series: Materials Science and Engineering, 78(2015), 1-8.
  18. Rahman, S. and Vanier, D. J. (2004), Life cycle cost analysis as a decision support tool for managing municipal infrastructure, Proceedings of the CIB triennial, CIB 2005 Triennial Congress, Toronto, Canada, 1-11.
  19. Salem, O., Abourizk, S., and Ariaratnam, S. (2003), Risk -Based Life-Cycle Costing of Infrastructure Rehabilitation and Construction Alternatives, Journal of Infrastructure Systems, 9(1), 6-15. https://doi.org/10.1061/(ASCE)1076-0342(2003)9:1(6)
  20. Song, H. W., Pack, S. W., Lee, C. H., and Kwon, S. J. (2006), Service life prediction of concrete structures under marine environment considering coupled deterioration, Journal of Restoration Building and Monuments, 12(4), 265-284.
  21. Swei, O., Gregory, J., and Kricahin, R. (2013), Probabilistic Characterization of Uncertain Inputs in the Life-Cycle Cost Analysis of Pavements, Transportation Research Record: Journal of the Transportation Research Board, 2366, 71-77.
  22. Thomas, M. D. A. and Bamforth, P. B. (1999). Modeling chloride diffusion in concrete: effect of fly ash and slag, Cement and Concrete Research, 29(4), 487-495. https://doi.org/10.1016/S0008-8846(98)00192-6
  23. Thomas, M. D. A. and Bentz, E. C. (2002), Life-365TM Service Life Prediction ModelTM and Computer program for Predicting the Service Life and Life-cycle Costs of Reinforced Concrete Exposed to Chlorides, SFA, 2-28.
  24. TOTAL-LCC (2010), Technical Manual, ver.1.1.