Reinforcing Steel Contractor Exam (C-
50) Questions and Correct Answers
(Verified Answers) Plus Rationales 2025
Q&A | Instant Download PDF
Question 1
What is the primary purpose of reinforcing steel in concrete?
A. To make concrete lighter
B. To resist tensile forces
C. To waterproof concrete
D. To reduce concrete curing time
Correct Answer: B
Rationale:
Concrete is very strong in compression but relatively weak in tension. Reinforcing
steel (rebar) provides tensile strength, allowing reinforced concrete to resist
cracking and bending loads. It does not make concrete lighter, waterproof it, or
shorten curing time.
Question 2
What is the common name for reinforcing steel bars used in concrete
construction?
A. Studs
B. Rebar
C. Joists
D. Channels
Correct Answer: B
,Rationale:
Reinforcing steel bars are commonly called rebar. Studs, joists, and channels are
structural framing components, not reinforcing bars.
Question 3
What is the primary purpose of the deformations (ribs) on reinforcing bars?
A. Reduce bar weight
B. Improve bond with concrete
C. Prevent corrosion
D. Increase flexibility
Correct Answer: B
Rationale:
The ribs on reinforcing bars improve the mechanical bond between steel and
concrete, helping prevent slippage. They do not reduce weight, stop corrosion, or
make the bar more flexible.
Question 4
Which tool is commonly used to tie reinforcing steel?
A. Pipe wrench
B. Tie wire twister
C. Mason's trowel
D. Framing hammer
Correct Answer: B
Rationale:
A tie wire twister or tying tool is specifically designed for fastening reinforcing
bars together using tie wire. The other tools serve different construction
purposes.
Question 5
,Tie wire is primarily used to:
A. Weld reinforcing bars together
B. Hold reinforcing bars in position
C. Increase concrete strength
D. Replace reinforcing bars
Correct Answer: B
Rationale:
Tie wire keeps reinforcing bars in the correct position until concrete is placed. It is
not intended to provide structural strength or replace welding where required.
Question 6
Before concrete is placed, reinforcing steel should be:
A. Properly positioned
B. Painted
C. Heated
D. Lubricated
Correct Answer: A
Rationale:
Correct placement is essential to ensure the reinforcement performs as designed.
Painting, heating, or lubricating reinforcement is generally unnecessary and may
interfere with bonding.
Question 7
What does the bar size number generally indicate?
A. Bar color
B. Approximate diameter
C. Bar length
D. Steel grade
Correct Answer: B
, Rationale:
The bar size number identifies the approximate nominal diameter of the
reinforcing bar. It does not indicate the length, color, or grade.
Question 8
Which material is most commonly used to support reinforcing bars above the
formwork?
A. Chairs
B. Nails
C. Bricks
D. Lumber blocks
Correct Answer: A
Rationale:
Rebar chairs support reinforcement at the correct height to maintain required
concrete cover. Nails, bricks, and lumber are not proper supports.
Question 9
Concrete cover refers to the:
A. Thickness of reinforcing steel
B. Distance from concrete surface to reinforcing steel
C. Width of the footing
D. Depth of excavation
Correct Answer: B
Rationale:
Concrete cover is the protective thickness of concrete between the outer surface
and the reinforcement. Proper cover helps protect against corrosion and fire.
Question 10
50) Questions and Correct Answers
(Verified Answers) Plus Rationales 2025
Q&A | Instant Download PDF
Question 1
What is the primary purpose of reinforcing steel in concrete?
A. To make concrete lighter
B. To resist tensile forces
C. To waterproof concrete
D. To reduce concrete curing time
Correct Answer: B
Rationale:
Concrete is very strong in compression but relatively weak in tension. Reinforcing
steel (rebar) provides tensile strength, allowing reinforced concrete to resist
cracking and bending loads. It does not make concrete lighter, waterproof it, or
shorten curing time.
Question 2
What is the common name for reinforcing steel bars used in concrete
construction?
A. Studs
B. Rebar
C. Joists
D. Channels
Correct Answer: B
,Rationale:
Reinforcing steel bars are commonly called rebar. Studs, joists, and channels are
structural framing components, not reinforcing bars.
Question 3
What is the primary purpose of the deformations (ribs) on reinforcing bars?
A. Reduce bar weight
B. Improve bond with concrete
C. Prevent corrosion
D. Increase flexibility
Correct Answer: B
Rationale:
The ribs on reinforcing bars improve the mechanical bond between steel and
concrete, helping prevent slippage. They do not reduce weight, stop corrosion, or
make the bar more flexible.
Question 4
Which tool is commonly used to tie reinforcing steel?
A. Pipe wrench
B. Tie wire twister
C. Mason's trowel
D. Framing hammer
Correct Answer: B
Rationale:
A tie wire twister or tying tool is specifically designed for fastening reinforcing
bars together using tie wire. The other tools serve different construction
purposes.
Question 5
,Tie wire is primarily used to:
A. Weld reinforcing bars together
B. Hold reinforcing bars in position
C. Increase concrete strength
D. Replace reinforcing bars
Correct Answer: B
Rationale:
Tie wire keeps reinforcing bars in the correct position until concrete is placed. It is
not intended to provide structural strength or replace welding where required.
Question 6
Before concrete is placed, reinforcing steel should be:
A. Properly positioned
B. Painted
C. Heated
D. Lubricated
Correct Answer: A
Rationale:
Correct placement is essential to ensure the reinforcement performs as designed.
Painting, heating, or lubricating reinforcement is generally unnecessary and may
interfere with bonding.
Question 7
What does the bar size number generally indicate?
A. Bar color
B. Approximate diameter
C. Bar length
D. Steel grade
Correct Answer: B
, Rationale:
The bar size number identifies the approximate nominal diameter of the
reinforcing bar. It does not indicate the length, color, or grade.
Question 8
Which material is most commonly used to support reinforcing bars above the
formwork?
A. Chairs
B. Nails
C. Bricks
D. Lumber blocks
Correct Answer: A
Rationale:
Rebar chairs support reinforcement at the correct height to maintain required
concrete cover. Nails, bricks, and lumber are not proper supports.
Question 9
Concrete cover refers to the:
A. Thickness of reinforcing steel
B. Distance from concrete surface to reinforcing steel
C. Width of the footing
D. Depth of excavation
Correct Answer: B
Rationale:
Concrete cover is the protective thickness of concrete between the outer surface
and the reinforcement. Proper cover helps protect against corrosion and fire.
Question 10
