Illinois Concrete Contractor Licensing
Examination Practice Test Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
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Q1. What is the minimum 28-day compressive strength commonly
specified for structural concrete in commercial construction?
A. 2,000 psi
B. 2,500 psi
C. 4,000 psi
D. 6,000 psi
Rationale: 4,000 psi is the standard minimum strength for structural
applications, providing adequate load-bearing capacity.
Q2. Which test measures concrete slump in the field?
,A. Flow table test
B. ASTM C143 cone test
C. Cylinder break test
D. Schmidt hammer test
Rationale: ASTM C143 uses an Abrams cone to measure consistency and
workability of fresh concrete.
Q3. What is the primary purpose of air entrainment in concrete?
A. Increase compressive strength
B. Improve freeze-thaw durability
C. Reduce curing time
D. Make concrete more dense
Rationale: Air voids relieve internal pressures caused by freezing water,
increasing durability.
Q4. The term "ACI" stands for what?
A. American Construction Institute
B. American Concrete Institute
C. American Cement Index
D. Aggregate Control Institute
Rationale: ACI is the American Concrete Institute, establishing standards
for concrete work.
,Q5. Which aggregate size is most commonly used in concrete mixes?
A. 3"
B. 3/4"
C. 1/8"
D. 2"
Rationale: 3/4" coarse aggregate is a standard size for general
construction concrete mixes.
Q6. What effect does adding excess water have on concrete?
A. Increases strength
B. Reduces shrinkage
C. Weakens the concrete
D. Improves hardened durability
Rationale: Extra water increases porosity, lowering compressive strength
and durability.
Q7. What is the typical minimum concrete cover for reinforcement on
grade?
A. 1/2"
B. 3/4"
C. 1"
, D. 3"
Rationale: Reinforcement in contact with earth requires 3 inches of cover
y y y y y y y y y y
y to prevent corrosion.
y y
Q8. Which finish is commonly required for exterior slabs exposed to
y y y y y y y y y y
y weather?
A. Dry shake finish
y y
B. Broom + burnish y y
C. Broom finish y
D. Mirror troweled y
Rationale: A broom finish provides traction for outdoor surfaces exposed to
y y y y y y y y y y
y moisture.
Q9. What is the main purpose of rebar?
y y y y y y y
A. Add weight y
B. Reduce curing time y y
C. Resist tensile forces y y
D. Create surface texture y y
Rationale: Concrete has low tensile strength; rebar compensates by
y y y y y y y y
y providing tensile resistance. y y
Q10. What is typically used to cure concrete?
y y y y y y y
Examination Practice Test Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
Q1. What is the minimum 28-day compressive strength commonly
specified for structural concrete in commercial construction?
A. 2,000 psi
B. 2,500 psi
C. 4,000 psi
D. 6,000 psi
Rationale: 4,000 psi is the standard minimum strength for structural
applications, providing adequate load-bearing capacity.
Q2. Which test measures concrete slump in the field?
,A. Flow table test
B. ASTM C143 cone test
C. Cylinder break test
D. Schmidt hammer test
Rationale: ASTM C143 uses an Abrams cone to measure consistency and
workability of fresh concrete.
Q3. What is the primary purpose of air entrainment in concrete?
A. Increase compressive strength
B. Improve freeze-thaw durability
C. Reduce curing time
D. Make concrete more dense
Rationale: Air voids relieve internal pressures caused by freezing water,
increasing durability.
Q4. The term "ACI" stands for what?
A. American Construction Institute
B. American Concrete Institute
C. American Cement Index
D. Aggregate Control Institute
Rationale: ACI is the American Concrete Institute, establishing standards
for concrete work.
,Q5. Which aggregate size is most commonly used in concrete mixes?
A. 3"
B. 3/4"
C. 1/8"
D. 2"
Rationale: 3/4" coarse aggregate is a standard size for general
construction concrete mixes.
Q6. What effect does adding excess water have on concrete?
A. Increases strength
B. Reduces shrinkage
C. Weakens the concrete
D. Improves hardened durability
Rationale: Extra water increases porosity, lowering compressive strength
and durability.
Q7. What is the typical minimum concrete cover for reinforcement on
grade?
A. 1/2"
B. 3/4"
C. 1"
, D. 3"
Rationale: Reinforcement in contact with earth requires 3 inches of cover
y y y y y y y y y y
y to prevent corrosion.
y y
Q8. Which finish is commonly required for exterior slabs exposed to
y y y y y y y y y y
y weather?
A. Dry shake finish
y y
B. Broom + burnish y y
C. Broom finish y
D. Mirror troweled y
Rationale: A broom finish provides traction for outdoor surfaces exposed to
y y y y y y y y y y
y moisture.
Q9. What is the main purpose of rebar?
y y y y y y y
A. Add weight y
B. Reduce curing time y y
C. Resist tensile forces y y
D. Create surface texture y y
Rationale: Concrete has low tensile strength; rebar compensates by
y y y y y y y y
y providing tensile resistance. y y
Q10. What is typically used to cure concrete?
y y y y y y y
