Flexural Strengthening of Beams and Slabs - Strengthening Design of Reinforced Concrete with FRP - page 145

b 6 in. (152.4 mm)

h 12 in. (304.8 mm)

C t 1 in. (25.4 mm)

C b 1 in. (25.4 mm)

h s 10 in. (254 mm)

b s 4 in. (101.6 mm)

C t

2-#3

h s

h

2-#5

# 3 stirrups
@ 5 in. o.c.

C b

b s
b

FIGURE 5.P.4
See Figure 5.P.4.

f = 5.2 ksi(35.9 MPa), f = 69.64 ksi(480.2 MPa), ε= 0

c y bi

t = 0.0065"(0.165 mm), E = 33,000 ksi(227.5 GPa), f = 550 ksi(3792 MPa)

f f fu

Decker used VWRAP C100 CFRP for strengthening. Use the same material to
strengthen the beam to a 20% increase in the unstrengthened beam moment capacity.
Assume no need to strengthen the beam in shear.

Problem 5.6
Repeat Problem 5.5 with a 40% strengthening ratio increase over the bare beam.
Designate the failure mode involved. Assume no need to strengthen the beam in shear.

Problem 5.7
Repeat Problem 5.5 with a 60% strengthening ratio increase over the bare beam.
Designate the failure mode involved. Assume fire not to be a hazard in this case.
Also, assume no need to strengthen the beam in shear.

Problem 5.8
Decker (2007) designed, built, strengthened, and tested reinforced concrete T-beams
having the following properties:

b f 16 in. (406.4 mm)

h f 4 in. (101.6 mm)

b w 6 in. (152.4 mm)

h w 8 in. (203.2 mm)