Background Knowledge - Strengthening Design of Reinforced Concrete with FRP - page 19

f y

60

Higher than Grade 60
Steel

Grade 60 Steel

Steel Strain

0.00207

0.0035

FIGURE 2.10 Typical stress-strain response of reinforcing steel.

Example 2.1: Analysis

For the reinforced concrete beam section shown in Figure 2.11, determine the
ultimate moment capacity by neglecting the compression reinforcement.

f
f

=
=

4ksi
60 ksi

c

y

Solution:

First, calculate the effective depth and area of tensile reinforcement using Table A-1
of Appendix A.

4
8

1
2

dd ==−−−× = 18 1.5 0.75 15.625 in.

t

40.441.76in. 2 A =× = s

ε cu =0.003 0.85 f c

a /2

2#3 a

c

C

#4
Stirrups

18"

1.5"

4#6

d t

T = A s f y

ε s

10"

FIGURE 2.11 Cross-section details, strain, and force profile for Example 2.1.