Indiana Concrete Contractor Exam
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. What is the primary purpose of reinforcement (rebar) in concrete?
A. Reduce cost
B. Increase tensile strength
C. Speed up curing
D. Improve color
Rebar increases the tensile strength because concrete is strong in
compression but weak in tension.
2. Which test measures concrete workability?
A. Compressive strength
B. Slump test
C. pH test
D. Permeability test
The slump test assesses consistency and workability of fresh
concrete.
3. Proper formwork should be designed to:
A. Absorb water
B. Support concrete until it gains strength
C. Act as permanent finish
D. Increase slump
Formwork must hold the concrete shape until it cures sufficiently.
4. Concrete’s typical 28-day compressive strength is measured in:
A. ft-lbs
B. psi
, C. pounds per square inch (psi)
D. gallons
Concrete strength is specified in psi at 28 days.
5. Which admixture accelerates setting?
A. Water-reducing
B. Retarder
C. Accelerator
D. Air-entraining
Accelerators reduce setting time.
6. A typical slump range for slabs is:
A. 0-1 in
B. 3-5 in
C. 6-8 in
D. 9-10 in
3-5 inches balances workability and strength.
7. What does a higher water-cement ratio generally cause?
A. Faster setting
B. Increased strength
C. Lower strength
D. Better durability
More water weakens the concrete matrix.
8. Air-entraining admixtures are used to:
A. Increase strength
B. Improve freeze-thaw durability
C. Reduce cost
D. Decrease slump
Entrained air improves freeze-thaw resistance.
9. Steel reinforcement must be free of:
A. Paint only
B. Concrete
C. Excessive rust
D. Water
Heavy rust can reduce bond with concrete.
10. Concrete should be cured to:
A. Speed cracking
, B. Maintain moisture for strength gain
C. Reduce strength
D. Increase water evaporation
Curing retains moisture so concrete gains strength.
11. What tool measures concrete depth?
A. Hammer
B. Chisel
C. Depth gauge
D. Tape only
Depth gauges are designed for measuring concrete thickness.
12. Which aggregate size affects workability?
A. Maximum aggregate size
B. Reinforcement bar size
C. Slump cone height
D. Formwork gap
Aggregate size influences concrete workability.
13. Concrete placed in cold weather may require:
A. Less cement
B. Protection against freezing
C. Hot aggregate removal
D. Less curing
Cold conditions can hinder hydration, requiring protection.
14. What is the purpose of control joints?
A. Decorative only
B. Direct where cracking occurs
C. Increase strength
D. Reduce weight
Control joints encourage cracking along planned lines.
15. Which finish gives a non-slip surface outdoors?
A. Smooth trowel
B. Broom finish
C. Brush finish
D. Polished finish
Broom finishes improve traction.
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. What is the primary purpose of reinforcement (rebar) in concrete?
A. Reduce cost
B. Increase tensile strength
C. Speed up curing
D. Improve color
Rebar increases the tensile strength because concrete is strong in
compression but weak in tension.
2. Which test measures concrete workability?
A. Compressive strength
B. Slump test
C. pH test
D. Permeability test
The slump test assesses consistency and workability of fresh
concrete.
3. Proper formwork should be designed to:
A. Absorb water
B. Support concrete until it gains strength
C. Act as permanent finish
D. Increase slump
Formwork must hold the concrete shape until it cures sufficiently.
4. Concrete’s typical 28-day compressive strength is measured in:
A. ft-lbs
B. psi
, C. pounds per square inch (psi)
D. gallons
Concrete strength is specified in psi at 28 days.
5. Which admixture accelerates setting?
A. Water-reducing
B. Retarder
C. Accelerator
D. Air-entraining
Accelerators reduce setting time.
6. A typical slump range for slabs is:
A. 0-1 in
B. 3-5 in
C. 6-8 in
D. 9-10 in
3-5 inches balances workability and strength.
7. What does a higher water-cement ratio generally cause?
A. Faster setting
B. Increased strength
C. Lower strength
D. Better durability
More water weakens the concrete matrix.
8. Air-entraining admixtures are used to:
A. Increase strength
B. Improve freeze-thaw durability
C. Reduce cost
D. Decrease slump
Entrained air improves freeze-thaw resistance.
9. Steel reinforcement must be free of:
A. Paint only
B. Concrete
C. Excessive rust
D. Water
Heavy rust can reduce bond with concrete.
10. Concrete should be cured to:
A. Speed cracking
, B. Maintain moisture for strength gain
C. Reduce strength
D. Increase water evaporation
Curing retains moisture so concrete gains strength.
11. What tool measures concrete depth?
A. Hammer
B. Chisel
C. Depth gauge
D. Tape only
Depth gauges are designed for measuring concrete thickness.
12. Which aggregate size affects workability?
A. Maximum aggregate size
B. Reinforcement bar size
C. Slump cone height
D. Formwork gap
Aggregate size influences concrete workability.
13. Concrete placed in cold weather may require:
A. Less cement
B. Protection against freezing
C. Hot aggregate removal
D. Less curing
Cold conditions can hinder hydration, requiring protection.
14. What is the purpose of control joints?
A. Decorative only
B. Direct where cracking occurs
C. Increase strength
D. Reduce weight
Control joints encourage cracking along planned lines.
15. Which finish gives a non-slip surface outdoors?
A. Smooth trowel
B. Broom finish
C. Brush finish
D. Polished finish
Broom finishes improve traction.
