Journal of the Korean Recycled Construction Resources Institute (한국건설순환자원학회논문집)

Korean Recycled Construction Resources Institute (한국건설순환자원학회)
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Simulation on Optimum Repairing Number of Carbonated RC Structure Based on Probabilistic Approach

확률론을 고려한 탄산화된 RC 구조물의 최적 보수시기 해석

  • 권성준 (한남대학교 건설시스템공학과)
  • Received : 2017.06.19
  • Accepted : 2017.08.22
  • Published : 2017.09.30
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Abstract

Carbonation is a representative deterioration for underground structure, which causes additional repair for service life. This study proposes a simplified equation for optimum repair timing without complicated probability calculation, considering initial and repair conditions For the work, initial service life, extended service life through repair, and their COVs(Coefficient of Variation) are considered, and the periods which can reduce number of repair are evaluated. Assuming the two service lives to be independent, the repair timings are derived from 10 to 50 years based on the probabilistic method, and the regression analysis technique for optimum repairing timing is proposed. Decreasing COV has insignificant effect on reducing repairing number but shows a governing effect on changes in probability near the critical repairing stage. The extension of service life through repairing is evaluated to be a critical parameter for reducing repairing number. The proposed technique can be efficiently used for maintenance strategy with actual COV of initial and additional service life due to repairing.

탄산화는 지하구조물에서 발생하는 대표적인 열화현상으로 내구성 문제를 야기하며, 이는 보수를 통하여 사용성능을 확보해야 한다. 본 연구는 확률론적인 방법을 고려하여 최적의 보수시기를 도출하며 초기 및 보수조건을 고려하여 복잡한 확률 해석 없이 최적의 보수시기 도출식을 제안하는 것이다. 이를 위해 초기시공에 따른 내구수명, 보수를 통해 연장된 내구수명, 그리고 각각의 변동성을 고려하여 보수횟수를 감소시킬 수 있는 기간을 평가하였다. 각각의 기간을 독립적으로 가정하여 10~50년간의 해석을 수행하였으며, 최적의 보수시기를 평가할 수 있는 식을 회귀분석을 통해 제안하였다. 변동계수의 변화는 보수횟수를 줄이는 데 큰 영향을 주지 못하지만 임계시점에서의 확률변화에 큰 영향을 주었다. 또한 보수재를 통한 내구수명의 증가는 보수횟수를 줄이는 데 큰 역할을 하였다. 제안된 식은 정량적인 수명의 변동성을 정의한다면 효과적인 유지관리 기법으로 사용될 수 있다.

Keywords

References

  1. CEB. (1997). New Approach to Durability Design, CEB Bulletin 238, 96-102.
  2. CEN. (2004). EN-1992-1-1: Eurocode 2: Design of Concrete Structure, European Committee for Standardization, Brussels, Belgium.
  3. Ishida, T., Chaube, R.P., Kishi, T., Maekawa, K. (1998). Modeling of pore content in concrete under generic drying wetting conditions, Concrete Library of JSCE, 31(564), 275-287.
  4. Izumi, I., Kita, D., Maeda, H. (1986). Carbonation, Kibodang Publication, Japan, 35-88.
  5. JSCE. (2007). Standard Specifications and Guidelines.
  6. Kwon, S.J. (2017). Probabilistic analysis of repairing cost considering random variables of durability design parameters for chloride attack, Korea Institute for Structural Maintenance and Inspection, Submitted.
  7. Kwon, S.J., Lee, B.J., Kim, Y.Y. (2014). Concrete mix design for service life of RC structures under carbonation using genetic algorithm, Advances in Materials Science and Engineering, 2014(653753), 1-13.
  8. Kwon, S.J., Na, U.J. (2011). Prediction of durability for RC columns 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
  9. Mulubrhan, F., Mokhtar, A.A., 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
  10. Nasir, M., Chong, H.Y., Osman, S. (2015). Probabilistic life cycle cost model for repairable system, IOP Conference series: Materials Science and Engineering, 78(2015), 1-8.
  11. Papadakis, V.G., Vayenas, C.G., Fardis, M.N. (1991). Physical and chemical characteristics affecting the durability of concrete, ACI Materials Journal, 88(2), 186-196.
  12. Rahman, S., 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.
  13. Salem, O., Abourizk, S., 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)
  14. Song, H.W., Kwon, S.J. (2007). Permeability characteristics of carbonated concrete considering capillary pore structure, Cement and Concrete Research, 37(6), 909-915. https://doi.org/10.1016/j.cemconres.2007.03.011
  15. Stewart, M.G., Mullard, J.A. (2007). Spatial time-dependent reliability analysis of corrosion damage and the timing of first repair for RC structures, Engineering Structure, 29(7), 1457-1464. https://doi.org/10.1016/j.engstruct.2006.09.004
  16. TOTAL-LCC. (2010), Technical Manual ver.1.1.
  17. Vesikari, E. (1988). Service Life of Concrete Structures with regard to Corrosion of Reinforcement, Technical Reports 533, Technical Report Center of Finland, Finland, 29-128.