Journal of the Korea institute for structural maintenance and inspection (한국구조물진단유지관리공학회 논문집)

Korea Institute for Structural Maintenance Inspection (한국구조물진단유지관리공학회)
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Flexural Behavior of RC Beam Repaired with Polymer Mortar

폴리머 모르타르로 보수된 철근콘크리트 보의 휨 거동

  • Received : 2016.09.23
  • Accepted : 2016.11.17
  • Published : 2017.01.01
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Abstract

The purpose of this paper is to evaluate the flexural performance of reinforced concrete (RC) beams repaired with polymer mortar. The repaired and non-repaired 13th beams which was fabricated by considering repair position, repair depth, and curing age of polymer mortar as test variables were tested under three point loading. All specimens repaired in compressive and tensile zone did not fail due to interfacial failure between polymer mortar and concrete but failed when the strain of repaired mortar exceeded the ultimate tensile strain of polymer mortar. Maximum load of specimens repaired in compressive zone was similar to that of non-repaired specimen, reference specimen. Additionally, their ductility index was higher than that of reference specimen. On the other hand, specimens repaired in tensile zone failed very brittlely and have a lower ductility index than reference specimen. Nonlinear analysis by using OpenSees was performed to predict the behavior of RC beam repaired with polymer mortar. Two dimension frame element was used to simplify an analysis model and fiber model was applied to consider the material non-linearity. It was confirmed from the analysis results that nonlinear analysis properly predicts the behavior of specimens repaired in compressive zone and overestimates the behavior of specimens repaired in tensile zone.

본 논문은 폴리머 모르타르로 보수된 철근콘크리트 보의 휨거동을 실험적 해석적으로 분석한 결과를 제시한다. 실험적 연구에서는 보수위치, 모르타르 재령을 실험변수로 고려하여 제작된 13개의 보에 대한 3점 휨실험이 실시되었다. 인장측 및 압축측을 보수한 실험체들의 파괴는 모르타르와 콘크리트의 계면에서 발생하지 않았으며, 폴리머 모르타르의 인장변형률이 극한변형률을 초과하는 순간 발생하였다. 압축측을 보강한 실험체들은 기준실험체의 최대하중과 유사하였다. 그들의 연성지수는 기준실험체보다 훨씬 컸다. 인장측을 보수한 실험체는 매우 취성적으로 파괴되었으며, 연성지수가 크게 감소하였다. 폴리머 모르타르로 보수된 철근콘크리트의 보의 휨거동을 예측하기 위해 Opensees을 사용한 재료비선형 해석을 진행하였다. 해석 모델을 단순화하기 위해 2차원 골조요소를 적용하였으며, 재료 비선형성을 고려하기 위해 파이버 모델을 적용하였다. 해석결과는 비선형 구조해석은 압축측 보수 실험체의 휨거동을 적절하게 예측하나, 인장측 휨거동는 다소 과대 평가하는 것으로 나타났다.

Keywords

References

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