Flexural Strengthening of Beams and Slabs - Strengthening Design of Reinforced Concrete with FRP - page 148

Problem 5.12
Al-Tamimi et al. (2011) have designed, built, strengthened, and tested the beam
shown in Figure 5.P.8 (B70PW). It has a CFRP plate extending 1352 mm along the
span of the beam covering 70% of the shear span. ReCon Plate CFL Grade CF210,
100-mm wide by 1.4-mm thick, was used to strengthen the beam ( f * fu = 2500 MPa,
E f = 215 GPa). The average measured compressive strength of the concrete was 54
MPa. The modulus of elasticity and yield strength for the tensile steel reinforcement
were 202 GPa and 611 MPa, respectively. Determine the capacity of the beam using
the ACI440.2R-08 model for plate debonding. Compare the ultimate load predicted
to the experimental ultimate load at plate debonding of 67.7 kN and conclude.

P

110 mm

a = 561.5 mm
d

a = 561.5 mm

567 mm

d = 155 mm

180 mm

d

200 mm 200 mm

1352 mm

100 mm
Section d-d

FIGURE 5.P.8

Problem 5.13
Wuertz (2013) designed, built, strengthened, and tested rectangular reinforced con-
crete beams having the section geometry shown in Figure 5.P.9:

1"

2-#3

10"

12"

2-#5

# 3 stirrups
@ 5 in. o.c.

1"

4"

6"

FIGURE 5.P.9

f = 9.4 ksi(64.9 MPa), f = 71ksi (490 MPa), ε= 0

c y bi

t = 0.05"(1.27 mm), E = 3030 ksi(20.9 GPa), f = 66.72 ksi(460.3 MPa)

f f fu

Wuertz used V-WRAP EG50 GFRP for strengthening in addition to two NSM
steel bars. The two NSM bars were installed in grooves in the concrete cover. The
GFRP was applied as one layer only and was wrapped 5” (127 mm) up the sides from
the soffit. Use the same strengthening design to determine the strengthened beam