ANALYSIS OF R/C BEAMS EXTERNALLY STRENGTHENED WITH CARBON FIBRE SHEETS

The use of CFRP sheets for the strengthening of reinforced concrete beams has demonstrated a feasible way to increase the load carrying capacity and stiffness of existing structures. It is very simple, easy and quick to install, requiring essentially unskilled labour although it is necessary an appropriate site supervision to ensure its quality. The thin CFRP sheets allow very little cross-sectional increases while providing the concrete element significant increases in strength and stiffness. The ultimate load increases were signficant although these values tend to a limit determined by the CFRP sheet debonding. Peeling off is found to be a typical failure mode. It is associated with high shear stress concentration at the ends of the CFRP sheets. Stiffness increases are evident. At a given load, rebar stresses and deflections were found to be smaller when compared to rebar stresses and deflections of control beams. Ultimate load capacities for the strengthened beams can be predicted with reasonable accuracy by conventional beam-bending theory (in accordance with the Brazilian code for concrete - NBR6118). The purely linear elastic behaviour of the CFRP sheets presents the use of the composite's full tensile strength. According to the experimental results, the maximum strain at the CFRP sheet was 10.6% ie 28% less than its full strain potential. (A) For the covering abstract see ITRD E106406.

Language

  • English

Media Info

  • Features: References;
  • Pagination: p. 492-9

Subject/Index Terms

Filing Info

  • Accession Number: 00801576
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0-7277-2854-7
  • Files: ITRD
  • Created Date: Nov 8 2000 12:00AM