This
paper presents the effect of the number and configuration of CFRP sheets on the
flexural strength and ductility
of RC beams and provides useful relationships
that can be effectively utilized to determine the required number of CFRP
sheets for a certain necessary increase in the beam flexural strength without a
major loss in its ductility. The reinforced concrete beams are identical in the
geometric and reinforcement details. The variables in this paper are the number
and configuration of CFRP sheets. The RC beams were modeled and analyzed using
the
nonlinear finite element ANSYS (Version 9) software package. The FEA
results were validated with the experimental test results of identical RC
beams. The validation of the FEA results with the experimental test results
concludes that the nonlinear FEA modeling could predict accurately the ultimate
load capacity, deflections, concrete strains, steel strains, and CFRP strains
of the CFRP
strengthened slabs. Analysis of the FEA shows that the normalized flexural
moment capacity (M/Mo)
of the beams strengthened with 1 layer (t/d = 0.00081) and 5 layers (t/d =
0.00406) of the U-wrap scheme were 1.7 and 2.7 times that of the control beam,
respectively. For the corresponding beams strengthened with the tension face
scheme, the M/Mo was
1.25 and 1.8 times that of the control beam, respectively. Approximately 5
layers of the tension face scheme are equivalent to 1 layer of the U-wrap
scheme. In both schemes, it was confirmed that after a certain t/d value, there
would be no further noticeable increase in the flexural strength of the beam,
while significant reduction in its ductility continues to occur.