Journal of the Korea Concrete Institute (콘크리트학회논문집)

Korea Concrete Institute (한국콘크리트학회)
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Bond Strength of Near Surface-Mounted FRP Plate in RC Member

콘크리트 내에 표면매입 보강된 FRP 판의 부착강도

  • Seo, Soo-Yeon (Dept. of Architectural Engineering, Korea National University of Transportation)
  • 서수연 (한국교통대학교 건축공학과)
  • Received : 2012.02.20
  • Accepted : 2012.04.12
  • Published : 2012.08.31
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Abstract

This paper analyzed seventy eight previous test results to evaluate bond strength of Near Surface-Mounted (NSM) FRP and prediction formulas previously proposed by researchers. The results showed that the most reliable bond strength prediction was the one proposed by Seracino, who considered the shape coefficient (ratio of width-thickness) and stiffness of FRP. However, the equation tended to underestimate the bond strength, especially serious when FRP bond length was relatively short, because the equation did not consider the effect of bond length. Based on the analysis of previous test results, the relation between bond length and bond strength and the group effect due to close proximity of FRPs were determined. Based on the findings, the Seracino's formula was modified and it's applicability was evaluated. The result showed that the suggested formula can be used effectively to predict the bond strength of NSM FRP.

이 연구에서는 FRP 부재를 이용한 표면매입 보강에서, FRP의 부착강도를 평가하기 위하여 총 78개의 기존실험 결과를 분석하고, 기존 연구자들에 의해 제안된 식들을 평가하였다. 그 결과 FRP부재의 형상계수(폭-두께비)와 강성을 반영한 Seracino의 식이 부착내력을 가장 근사하게 예측하는 것으로 나타났다. 그러나 Seracino의 식은 실험 결과를 다소 과소평가하는 양상을 보이고 특히 부착길이가 작을수록 그 경향이 두드러진 것으로 나타났다. 이는 부착길이 증가에 따른 영향이 Seracino의 식에는 전혀 반영되어있지 않기 때문으로 볼 수 있다. 기존 실험 결과의 분석을 통하여 부착길이와 강도와의 상관관계를 찾고 또한 여러 개의 FRP부재를 인접하여 배치시 발생하는 무리효과를 고려하여 Seracino 식을 수정 제안하였다. 이 제시된 식을 이용하여 기존 실험체에 대한 내력을 계산하고 평가한 결과, 제안된 식으로서 표면매입 보강된 FRP의 부착강도를 매우 근사하게 예측할 수 있는 것으로 나타났다.

Keywords

References

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  2. Evaluation on the Thermal Resistance Capacity of Fire Proof Materials for Improving Fire Resistance of Near-Surface-Mounted FRP in Concrete vol.18, pp.5, 2014, https://doi.org/10.11112/jksmi.2014.18.5.051
  3. Flexural Strength of RC Beam Strengthened by Partially De-bonded Near Surface-Mounted FRP Strip vol.10, pp.2, 2016, https://doi.org/10.1007/s40069-016-0133-z
  4. Bond Strength of Near Surface-Mounted FRP Plate in Concrete Corresponding to Space and Bond Length vol.25, pp.1, 2013, https://doi.org/10.4334/JKCI.2013.25.1.037
  5. Analysis on the Interfacial Bond-Slip Relationship between ear Surface-Mounted FRP Plate and Concrete vol.26, pp.1, 2014, https://doi.org/10.4334/JKCI.2014.26.1.079