Overview
Problem 1
A reinforced concrete beam has a rectangular cross-section as shown in Figure 1.
a) Calculate the steel reinforcement area.
b) Calculate the steel reinforcement ratio.
Given:
· Compressive strength, f’c= 5,000 psi
· Rebar yield strength, fy= 60 ksi
· Rebars: 3 No. 10
Parameters:
· b= 12 in
· d= 19 in
· clear cover, cc= 3 in
Problem 2
For the beam cross-section in Problem 1, determine:
a) The minimum steel reinforcement area required by code.
b) The minimum steel reinforcement ratio required by code.
c) Does the provided reinforcement meet the code requirements?
Problem3
For the beam cross-section in Problem 1, determine:
a) Whether the section is tension-controlled, or compression controlled.
b) Strength reduction factor for bending.
Problem 4
A single-span reinforced concrete beam with simple supports is uniformly
loaded as shown in Figure 1. Verify if the section is adequate for the
applied loads.
Given:
· Distributed superimposed dead load, qSDL= 400 lbf/ft
· Distributed live load, qLL= 500 lbf/ft
· Weight of concrete, sw= 150 lbs/ft3 (normal weight)
Parameters:
· L= 40 ft (span)
Hint:
1. Calculate the self-weight of the beam (lbs/ft) and add to super superimposed dead load to obtain the DL distributed
load.
2. Use Tabulated Moments and Deflections for Beams provided in the lecture notes 3.
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Problem 5
A concrete hanger and a concrete beam are shown in Figure 3.
Which one of these members must be designed with tension
reinforcement? Please explain your answer.
Problem 6
A concrete wall is supported at the base (Figure 4) and loaded at the top.
a) Does the wall need tension reinforcement? Please explain your answer.
b) Where would the replacement need to be placed, close to side A or B?