H. El-Chabib, PhD, P. Eng.
PENN STATE UNIVERSITY
Department of Civil and Environmental Engineering
Design of Reinforced Concrete Structures
Exam #1
Name: ……………………………………….
ID #: ……………….................……….
Time: 130 minutes
Instructions:
1. ONLY use of ACI code and lecture notes (excluding worked-out problems) IS PERMITTED.
2. CELL PHONES are permitted to use CamScanner Only.
3. CONNECTION TO THE INTERNET ARE NOT PERMITTED EXCEPT TO ACCESS
CANVAS.
4. Provide an organized, neat, and legible solution on engineering papers and in pencil.
5. Write all final answers in three significant figures in the space provided and/or circle them in your
solution.
6. Scan your solution with the exam papers on top (if applicable) in a single pdf file and upload to
canvas
7. Mark and estimated time for each question are shown.
Question No. 1 (15 minutes):
[10 %]
A simply supported beam with the inverted T cross section
shown supports a moment of 65 k-ft. If the compressive
strength of concrete is f’c = 4000 psi,
Ȳ = 18.43 in
Determine the cracking moment in k-ft. (the moment at
which the concrete starts to crack) and check if the
concrete will crack under the applied moment.
cr
=
Note that the location of the neutral axis is given, Ȳ = 18.43 in. from the top of the section.
Exam #1
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H. El-Chabib, PhD, P. Eng.
Question No. 2 (10 minutes):
[10 %]
The cross section shown is reinforced with 6 #9 tension steel and 2 #9
compression steel. If the tension force in the tension steel T = 360 k and the
2#9
compression force in the concrete Cc = 260 k, Determine the strain in the
compression steel, ε’s
's
6#9
=
Question No. 3 (50 minutes):
[40 %]
The cantilever beam shown in the figure bellow supports a uniform service (unfactored) dead load
of 1 kip/ft plus its own weight and a concentrated service (unfactored) live load of 12 kips, as
shown. The concrete is normal-weight with f’c = 4500 psi and the steel is Grade 60. The beam is
reinforced with 6 #8 steel bars as shown.
1- Determine the Maximum ultimate moment, Mu
Mu
=
kip-ft
2- Determine 

=
3- Determine min according to ACI 318
min
=
4- Determine the strain in the steel bars
s
=
5- Compute Mn
ɸMn
=
kip-ft
6- Is the beam safe and meet ACI requirements? explain
Exam #1
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H. El-Chabib, PhD, P. Eng.
Question No. 4 (45 minutes):
[40 %]
A simply supported beam of 30 feet span with the cross section shown supports a service uniform
deal load, WD = 1.05 kips/ft in addition to the beam’s self-weight (Ws) and a service point live
load at mid-span, PL. If the depth of the neutral axis from the top of the section is 6.4 in., h =
36.0 in., the space between steel layers is 2.0 in (c/c), all steel bars are #9, and Using f’c = 4000
psi and fy = 60000 psi,
1- Plot the strain diagram, stress diagram, and force diagram with details and numbers.
2- Check If the compression steel yields and determine the stress in the compression steel
f's
=
3- Check if the section is tension-controlled and calculate the design moment capacity of the
section.
ɸMn
Exam #1
=
kip-ft
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