Journal of the Korea Concrete Institute (콘크리트학회논문집)

Korea Concrete Institute (한국콘크리트학회)
권호 표지
DOI QR코드

DOI QR Code

The Combined Effect of Concrete Environment and High Temperature on Interlaminar Shear Strength of FRP Reinforcement

콘크리트 환경과 고온의 복합환경이 FRP 보강근의 계면전단성능에 미치는 영향

  • Moon, Do-Young (Dept. of Civil Engineering, Kyungsung University) ;
  • Oh, Hong-Seob (Dept. of Civil Engineering, Gyeongnam National Univ. of Sci. and Tech.)
  • 문도영 (경성대학교 토목공학과) ;
  • 오홍섭 (경남과학기술대학교 토목공학과)
  • Received : 2011.07.11
  • Accepted : 2011.11.16
  • Published : 2011.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Most experimental studies on durability of FRP reinforcements subjected to high temperature have focused on the effect of high temperature only on tensile properties. But FRP reinforcement used in newly constructed concrete structure is first degraded by moisture and alkaline environment of concrete. When the structure is subjected to fire, the degraded FRP reinforcement is exposed to high temperature. Therefore, the effects of concrete environment and high temperature should be simultaneously considered for evaluation of FRP reinforcement damaged by fire. In this study, FRP reinforcements submerged in simulated solutions of pH 12.3 and 7 for extended period of time were subjected to temperatures of $60^{\circ}C$, $100^{\circ}C$, $150^{\circ}C$, and $300^{\circ}C$ to be examined. In order to investigate the effect of the high temperature, interlaminar shear strengths were measured and compared to those of control ones. The experimental results demonstrated that the combined effect of concrete environment and high temperature on properties of FRP reinforcement was more significant than the effect of high temperature or concrete environment solely.

FRP 보강근의 화재 노출시 내구성능에 대한 연구들은 고온 노출이 인장성능에 미치는 영향에 대한 분석이 대부분을 차지한다. 그러나, 신설 구조물에 삽입된 FRP 보강근은 먼저 콘크리트 내에서 습윤환경 및 알칼리에 의한 성능저하가 발생하며, 이와 같은 FRP 보강 콘크리트 구조물에 화재가 발생하면, 보강근은 고온에 노출된다. 그러므로 화재에 의해 손상 받은 FRP 보강근의 평가시에는 콘크리트 환경과 고온에 의한 영향을 동시에 고려하여야 한다. 이 연구에서는 장기간동안 용액에 노출된 FRP 보강근에 $60^{\circ}C$, $100^{\circ}C$, $150^{\circ}C$ 및 $300^{\circ}C$의 온도를 가하고, 계면전단강도를 측정, 비교 하였다. 실험 결과에 따르면, 환경과 고온의 복합영향이 FRP 보강근의 역학적 특성에 미치는 영향이 환경만의 영향 또는 고온만의 영향 보다 큰 것으로 나타났다.

Keywords

References

  1. Wang, Y. C. and Kodur, V. K. R., "Variation of Strength and Stiffness of Fibre Reinforced Polymer Reinforcing Bars with Temperature," Cement & Concrete Composites, Vol. 27, Issues 9-10, 2005, pp. 864-874. https://doi.org/10.1016/j.cemconcomp.2005.03.012
  2. Blontrock, H., Taerwe, L., and Matthys, S., "Properties of Fiber Reinforced Plastics at Elevated Temperatures with Regards to Fire Resistance of Reinforced Concrete Members," In: Fourth International Symposium on Non-Metallic (FRP) Reinforcement for Concrete Structures, Baltimore, American Concrete Institute, 1999, pp. 43-54.
  3. Katz, A., Berman, N., and Bank, L. C., "Effect of High Temperature on Bond Strength of FRP Rebars," Composites for Construction, Vol. 3, No. 2, 1999, pp. 73-81. https://doi.org/10.1061/(ASCE)1090-0268(1999)3:2(73)
  4. Gentry, T. and Husain, M., "Thermal Compatibility of Concrete and Composite Reinforcements," Composites for Construction, Vol. 3, No. 2, 1999, pp. 82-86. https://doi.org/10.1061/(ASCE)1090-0268(1999)3:2(82)
  5. Saafi, M., "Effect of Fire on FRP Reinforced Concrete Members," Composite Structures, Vol. 58, Issue 1, 2002, pp. 11-20. https://doi.org/10.1016/S0263-8223(02)00045-4
  6. Aiello, M. A., Focacci, F., Huang, P. C., and Nanni, A., "Cracking of Concrete Cover in FRP Reinforced Concrete Elements under Thermal Loads," Selected Presentation Proc., 4 International Symposium on FRP for Reinforcement of Concrete Structures (FRPRCS4), Baltimore, USA, 1999, pp. 233-243.
  7. Galati, N., Nanni, A., Dharani, L. R., Focacci, F., and Aiello, M. A., "Thermal Effects on Bond between FRP Rebars and Concrete," Composites: Part A, Vol. 37, Issue 8, 2006, pp. 1223-1230. https://doi.org/10.1016/j.compositesa.2005.05.043
  8. Bisby, L. A. and Kodur, V. K. R., "Evaluating the Fire Endurance of Concrete Slabs Reinforced with FRP Bar: Considerations for a Holistic Approach," Composites : Part B, Vol. 38, Issues, 5-6, 2007, pp. 547-558. https://doi.org/10.1016/j.compositesb.2006.07.013
  9. Elbadry, M. and Elzaroug, O., "Control of Cracking due to Temperature in Structural Concrete Reinforced with CFRP Bars," Composite Structures, Vol. 64, Issue 1, 2004, pp. 37-45. https://doi.org/10.1016/S0263-8223(03)00211-3
  10. Elbdry, M. M., Abdalla, H., and Ghali, A., "Effects of Temperature on the Behaviour of Fiber Reinforced Polymer Reinforced Concrete Members: Experimental Studies," Canadian Journal of Civil Engineering, Vol. 27, 2000, pp. 993-1004. https://doi.org/10.1139/l00-013
  11. Robert, M. and Benmokrane, B., "Effect of Aging on Bond of GFRP Bars Embedded in Concrete," Cement & Concrete Composites, Vol. 32, Issue 6, 2010, pp. 461-467. https://doi.org/10.1016/j.cemconcomp.2010.02.010
  12. Masmoudi, R., Masmoudi, A., Ouezdou, M. B., and Daoud, A., "Long-Term Bond Performance of GFRP Bars in Concrete under Temperature Ranging from 20 to 80," Construction and Building Materials, Vol. 25, Issue 2, 2011, pp. 486-493. https://doi.org/10.1016/j.conbuildmat.2009.12.040
  13. Abbasi, A. and Hogg, P. J., "Temperature and Environmental Effects on Glass Fibre Rebar: Modulus, Strength and Interfacial Bond Strength with Concrete," Composites: Part B, Vol. 36, Issue 5, 2005, pp. 394-404. https://doi.org/10.1016/j.compositesb.2005.01.006
  14. 문도영, 오홍섭, "알칼리저항 초단유리섬유를 리브에 사용한 유리섬유보강근의 내구성능," 구조물진단학회지, 15권, 1호, 2011, pp. 281-287.

Cited by

  1. Prediction of Long-term Residual Inter-laminar Shear Strength of Thermally Damaged GFRP Rebar vol.18, pp.3, 2014, https://doi.org/10.11112/jksmi.2014.18.3.108
  2. Critical Temperature for Inter-Laminar Shear Strength and Effect of Exposure Time of FRP Rebars vol.25, pp.1, 2013, https://doi.org/10.4334/JKCI.2013.25.1.045