Analysis and Design of T Beams and Doubly Reinforced Beams - Design of Reinforced Concrete - page 138

Properties of the Reinforcing Steel
f y = 60000 psi
E s = 29000000 psi
Yield strain = 0.00207 in/in
Specified Dimensions
b = 15.00 in.
d = 20.00 in.
d 1 = 4.000 in.
h = 23.00 in.
Computed design data for the bending moment specified
Required A s =
Required A s =
C = 7.500 in
Steel strain = 0.00500 in/in
Compression steel strain = 0.00140 in/in
Compression steel stress = 40600.00000 psi

7.558 sq. in.

3.162 sq. in.

PROBLEMS

5.1 What is the effective width of a T beam? What does it
represent?
5.2 What factors affect the selection of the dimensions of
T beam stems?
5.3 If additional reinforcing bars are placed only in the
compression side of a reinforced concrete beam, will they
add significantly to the beam's flexural strength? Explain
your answer.
5.4 Why is compression reinforcing particularly impor-
tant in reinforced concrete flexual members located in
earthquake-prone areas?

5.6 Repeat Problem 5.5 if four #10 bars are used.

5.7 Repeat Problem 5.5 if ten #7 bars are used. ( Ans.
721.4 ft-k)

Problem 5.8

effective width = 36"

Analysis of T Beams
In Problems 5.5 to 5.15 determine the design moment
strengths of the sections shown. Use f y

3"

60,000 psi and

c c

f 4000 psi, except for Problem 5.9 where f 5000

32"

psi. Check each section to see if it is ductile.
Problem 5.5 ( Ans. 369.1 ft-k)

6 #10

effective width = 40"

3"

14"

28"

c

5.9 Repeat Problem 5.8 if f 5000 psi. ( Ans. 1042 ft-k)

3 #9

14"

5.10 Repeat Problem 5.8 if eight #9 bars are used.