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Evaluation of Reinforced Concrete T-Beams Retrofitted in Shear with Mechanically Anchored Dry Carbon Fiber Sheets

Abstract

Externally bonded fiber-reinforced polymer (FRP) composites are commonly used to retrofit concrete beams in shear. However, debonding failure limits the effectiveness of such a system. Mechanically anchored systems eliminate the debonding mode of failure, which maximizes the effectiveness of the retrofit system. This study investigates the effectiveness of using a modified mechanical anchor to strengthen concrete T-beams in shear. The fabrication and design details of this system are discussed. Three reinforced concrete (RC) T-beams were tested up to failure under a four-point bending test to assess the effectiveness of the proposed retrofit system. One beam was tested as a control beam, while two beams were strengthened in shear using mechanically anchored dry carbon fiber (CF) sheets. The tested beams were instrumented with conventional instruments to monitor the load, strain, displacement, and acoustic sensors to monitor the damage initiation, progression, and location. The modified mechanical anchor retrofit system increased the shear capacity by up to 22 %. The acoustic emissions (AE) monitoring of the tested T-beams was able to detect the locations of the cracks that caused the failure of the beams.

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Acknowledgements

The authors would like to acknowledge the financial support from the Natural Sciences and Engineering Research Council of Canada (NSERC). The Acoustic Emission analysis would not have been possible without the collaboration of TISEC Inc.; their equipment, efforts, and technical contributions are acknowledged. The authors would like to extend their acknowledgments to Juan Mejia and Thomas Bird for their technical support in the acoustic emission setup.

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Correspondence to K. Galal.

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El-Tahan, M., Hassanein, A., Megid, W.A. et al. Evaluation of Reinforced Concrete T-Beams Retrofitted in Shear with Mechanically Anchored Dry Carbon Fiber Sheets. Exp Tech (2021). https://doi.org/10.1007/s40799-021-00497-7

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Keywords

  • Dry carbon fibre sheets
  • Retrofitting
  • Reinforced concrete
  • T-beams
  • Acoustic Emission monitoring
  • Structural evaluation.