Journal of the Korea Concrete Institute (콘크리트학회논문집)

Korea Concrete Institute (한국콘크리트학회)
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Recommendations of Environmental Reduction Factor of FRP Rebar for Durability Design of Concrete Structure

콘크리트 보강용 FRP 보강근의 내구성 설계를 위한 환경영향계수의 제안

  • Park Chan-Gi (Dept. of Civil and Environmental System Engineering, Konkuk University) ;
  • Won Jong-Pil (Dept. of Civil and Environmental System Engineering, Konkuk University) ;
  • Kang Joo-Won (School of Architecture, Yeungnam University)
  • 박찬기 (건국대학교 사회환경시스템공학과) ;
  • 원종필 (건국대학교 사회환경시스템공학과) ;
  • 강주원 (영남대학교 건축학부)
  • Published : 2004.08.01
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Abstract

The corrosion of steel rebars has been the major cause of reinforced concrete deterioration. FRP(Fiber-reinforced polymer) rebar has emerged as one of the most promising and affordable solutions to the corrosion problems of steel reinforcement in structural concrete. However, FRP rebar is prone to deteriorate due to other degradation mechanisms than those for steel. The high alkalinity of concrete, for instance, is a possible degradation source. Therefore, the USA, Japan, Canada, UK. etc are using environmental reduction factor. Although difference design guidelines were drawn in many, including USA, Japan, Canada, UK etc, recommendations and coefficients that could take into account the long-term behavior of FRP reinforcement were not well defined. This study focuses on recommendation of environmental reduction factor of FRP rebar. Environment reduction factor were decided using durability test result. FRP rebars were subjected to twelve type of exposure conditions including alkaline solution, acid solution, salt solution and deionized water etc. The water absorption behavior was observed by means of simple gravimetric measurements and durability properties were investigated by performing tensile, compressive and short beam tests. Based on the experimental result, environmental reduction factor of hybrid FRP rebar(A), and (C) and CFRP rebar was decided as 0.85. Also, hybrid FRP rebar(B) and GFRP rebar were decided as 0.7 for the environmental reduction factor

철근콘크리트 구조물의 주요 파괴 원인은 철근의 부식에 의한 것으로 철근의 부식에 대한 문제점을 해결할 가능성이 있는 재료 중 FRP 보강근은 그 가능성이 높다. 그렇지만 이와 같은 FRP 보강근은 보강철근과 다른 파괴 메카니즘에 의하여 현저하게 성능이 저하될 가능성을 가지고 있다. 이와 같은 환경에는 알칼리 환경 등이 있다. 따라서 미국, 일본 캐나다 등 많은 나라에서는 환경영향계수를 사용하고 있다. 그렇지만 환경영향계수는 각 나라마다 다르게 적용되고 있는데 이는 FRP 보강근에 대한 장기거동에 대하여 명확한 기준이 제시되어 있지 않기 때문이다. 본 연구에서는 FRP 보강근의 환경영향계수를 제안하는데 그 목표를 두고 있다. 환경영향계수는 내구성 시험결과를 기본으로 하여 결정하였다. FRP 보강근은 알칼리 산 염해 등을 포함한 환경조건에 노출하였다. FRP 보강근은 간단한 질량변화를 측정하여 수분흡수 거동을 평가하였으며 역학적 특성의 변화는 인장, 압축 및 전단시험을 통하여 평가하였다. 시험결과를 기본으로하여 하이브리드 FRP 보강근(A)와 (C) 및 CFRP 보강근은 환경영향계수를 0.85로 결정하였고 하이브리드 FRP 보강근(B) 및 GFRP 보강근은 0.70으로 결정하였다.

Keywords

References

  1. ACI Report 440R, 'Stote-of-the-art report on fiber reinforced plastic reinforcement for concrete structure,' Reported by ACI Committee 440, Detroit, MI, USA, 1996, pp.1~36
  2. ACI, 'Guide for the Design and Construction of Concrete Reinforced with FRP bars,' Ameriam Concrete Institute Commiittee 440, Detroit, MI, USA, 2000, pp.1~78
  3. ASTM, 'American Society for Testingand Materials,' ASTM D 4475 Standard Test Method for Apparent Horizontal Shear Strength of Pultruted Reinforced Plastic Rods By The Short Beam Method, USA, 1998
  4. Castro, P.E. and Carino, N.J., 'Tensile and Non Destructive Testing of FRP bars,' J. Comp. Constr., Vol. 2, No.1, February, 1998, pp.17~27 https://doi.org/10.1061/(ASCE)1090-0268(1998)2:1(17)
  5. Chin J.W., Aouadi K., and Nguyen T., 'Effects of Environmental Exposure on Fiber-Reinforced Plastic (FRP) Materials Used in Construction,' Journal of Composites and Technology Research, Vol.19, No.4, 1997, pp.205~213 https://doi.org/10.1520/CTR10120J
  6. Canadian Standards Association, 'Canadian Highways Bridge Design Code,' Section 16, Fiber Reinforced Structures, 1996, 28pp
  7. Thvalapura, R.K., Gauchel, J.V., Greenwood, M.E., Hankin, A, and Humphrey, T., 'Long-Term Durability of GFRP Composites in Alkaline Environments,' Proc. 3rd Non-Metallic (FRP) Reinforcement for Concrete Structures, International Symposium, Sapporo, Japan, October 14-16th , Vol.2, 1997, pp.83~90
  8. Jarm Society of Civil Engineers (JSCE), 'Rronmrrlation for Design and Construction of Concrete Structures Using Continuous Fiber Reinforcing Materials,' Concrete Engineering Series, No.23, 1997, 325pp
  9. Katsuki F and Uomto T, 'Prediction of Deterioration of FRP Rcxls Due to Alkali Attack;' Non-Metallic (FRP) Reinforcement for Concrete Stroctures, 1995, pp.82~69
  10. Litherland, K.L., Oakley, D.R., and Proctor, B.A., 'The Use of Accelerated Ageing Procedures to Predict the Long Term Strength of GRC Composites,' Cement and Comrete Research, Vol.11, 1981, pp.455~466 https://doi.org/10.1016/0008-8846(81)90117-4
  11. Nanni, A. and Francesco, M., 'Mechanical properties and durability of FRP rods,' CIES 00-22, Darpartment of Civil Engineering, University of Missouri-Rolla, U.S.A., 2001
  12. Salah U. Al-Dulaijan, Mesfer M. Al-Zahrani, Antonio Nammi, Charles E. Bakis, and Thomas E. Boothy, 'Effect of Environmental Pre-conditioning on Bond of FRP Reinfocement to Concrete,' Journal of Reinforced Plastics and Composites, Dec. 1999, pp.1~25
  13. Sheard, P., Clarke, J., Dill, M, Hammersley, G., and Richardson, D., 'Eurocrete-Taking Account of Durability for Design of FRP Reinforced Concrete Structures,' Non-Metallic (FRP) Reinforcement for Concrete Stroctures: Proceedings of the Third International Symposium, Vol.2, Sapporo, Oct. 1997, pp.75~82
  14. Ssadatmznesh H and Tannous F, 'Durability of FRP Rebar and Tendon,' Non-Metallic (FRP) Reinforcementfor Concrete Structures: Proceedings of ther Third International Symposium, Vol.2, Sapporo, 1997, pp.107~114
  15. Vijay P.V., 'Aging and Design of Concrete Members Reinforced with CFRP Bars,' PhD. thesis, Thpartment of Civil Engineering West Virginia University, Morgantown, West Verginia, USA, 1999

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