Analytical Evaluation of Effect of Bond Properties on Behavior of FRP-Strengthened Reinforced Concrete Girders

Externally bonded carbon fiber reinforced polymer (CFRP) laminates are a feasible and economical alternative to traditional methods for strengthening and stiffening deficient reinforced and prestressed concrete bridge girders. The behavior of bond between FRP and concrete is the key factor controlling the behavior of these structures. Several experiments showed that debonding failure occurs frequently before FRP rupture and therefore the FRP strength can not be fully utilized. For design accuracy, the FRP strength must be reduced. This paper analyzes the effect of the bond properties on the response and failure modes of FRP-strengthened RC beams. A nonlinear RC beam element model with bond-slip between the concrete and the FRP laminates is used to analyze several test specimens and to investigate the corresponding failure mode, and whether it is due to FRP rupture, debonding, or concrete crushing. The model was also used to study the reduction factor of FRP tensile strength of simply supported strengthened RC girders due to debonding failure. This reduction factor is directly affected by the bond strength between FRP and concrete interface. It is also affected by different parameters, such as concrete strength, thickness of FRP, modulus of FRP, width of FRP laminate and FRP bond area. A large number of beam specimens were analyzed in order to conduct a thorough evaluation of current bond design specifications for RC bridge beams strengthened with FRP laminates. Based on these studies, new equations for the limitation set on the strength of FRP sheets in order to prevent debonding failure have been proposed.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 26p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01046003
  • Record Type: Publication
  • Report/Paper Numbers: 07-2223
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 6:54PM