Non-Destructive Testing of GFRP-Wrapped Reinforced-Concrete Slabs

Externally bonded fiber-reinforced polymer (FRP) composite systems have been increasingly used to rehabilitate concrete structures. These systems are critical to enhance the durability and capacity of the strengthened structures. There is a need to effectively evaluate the potential for debonding and deterioration of the rehabilitated system components. Non-destructive testing techniques appear to be a good solution to assess these rehabilitated structures. This paper presents an investigation on using ground-penetrating radar (GPR) and infrared tomography (IRT) methods to evaluate reinforced-concrete (RC) slabs externally bonded with glass fiber-reinforced polymer (GFRP). Four GFRP-wrapped RC slab specimens were experimentally tested. Artificial vertical cracks, voids, and debondings were made on the top surface of the RC slabs. Test parameters include the size of embedded steel rebars, depths of the vertical cracks, sizes and depths of the voids, and dimensions and thickness of the debonding. GPR image reconstruction method was established based on the modified synthetic aperture focusing technique (SAFT). An in-house developed software using this image reconstruction technique can provide sharp and high-resolution images of the FRP-strengthened RC slabs in comparison to those obtained by the device’s original software. The results reveal that the GPR technique can accurately determine locations and sizes of the embedded steel rebars and artificial voids. The pilot study of the IRT camera indicates the promising applications of the IRT technique for detecting and locating near-surface defects. This study suggests that the combinations of the GPR and IRT techniques can be an effective means for imaging internal defects of concrete structures.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; References; Tables;
  • Pagination: 16p

Subject/Index Terms

Filing Info

  • Accession Number: 01763405
  • Record Type: Publication
  • Report/Paper Numbers: TRBAM-21-03354
  • Files: TRIS, TRB, ATRI
  • Created Date: Feb 4 2021 10:54AM