AR CC Concrete Contractor Exam
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. What is the primary purpose of reinforcing steel (rebar) in concrete?
A) To improve color
B) To prevent cracking
C) To increase tensile strength
D) To make concrete lighter
C) To increase tensile strength
Rationale: Concrete is strong in compression but weak in tension. Rebar
provides tensile strength.
2. What is the typical water-cement ratio range for structural concrete?
A) 0.1–0.2
B) 0.3–0.5
C) 0.6–0.8
D) 0.9–1.0
B) 0.3–0.5
Rationale: A water-cement ratio of 0.3–0.5 ensures proper hydration while
maintaining strength.
3. Which type of cement is commonly used for general-purpose concrete?
A) Type I
B) Type II
C) Type III
D) Type IV
,A) Type I
Rationale: Type I cement is standard for general construction with normal
strength and setting time.
4. What is slump in concrete testing?
A) Strength measurement
B) Workability measurement
C) Water content measurement
D) Density measurement
B) Workability measurement
Rationale: Slump test measures the consistency or workability of fresh
concrete.
5. What is the recommended curing period for most concrete to reach
adequate strength?
A) 1 day
B) 3 days
C) 7 days
D) 28 days
D) 28 days
Rationale: Concrete continues to gain strength over time; 28 days is
standard for design strength.
6. Which aggregate size is generally used in concrete for reinforced
structural elements?
A) 5–10 mm
B) 10–20 mm
C) 20–40 mm
D) 50–70 mm
B) 10–20 mm
Rationale: Moderate aggregate size ensures proper bonding with rebar and
workability.
7. What is the function of admixtures in concrete?
A) Only to color concrete
, B) Modify properties such as workability, setting time, or durability
C) Replace cement completely
D) Reduce aggregate size
B) Modify properties such as workability, setting time, or durability
Rationale: Admixtures adjust specific concrete characteristics without
replacing cement.
8. Which type of concrete is designed to resist freezing and thawing
cycles?
A) Lightweight concrete
B) Air-entrained concrete
C) High-density concrete
D) Rapid-set concrete
B) Air-entrained concrete
Rationale: Entrained air improves resistance to freeze-thaw damage.
9. What is the primary cause of plastic shrinkage cracks?
A) Excess water
B) Rapid surface drying
C) Poor aggregate
D) Low cement content
B) Rapid surface drying
Rationale: Fast moisture loss before setting causes plastic shrinkage
cracks.
10. Which test is used to measure hardened concrete strength?
A) Slump test
B) Compression test
C) Flow table test
D) Penetration test
B) Compression test
Rationale: Compressive strength is the standard measure for hardened
concrete quality.
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. What is the primary purpose of reinforcing steel (rebar) in concrete?
A) To improve color
B) To prevent cracking
C) To increase tensile strength
D) To make concrete lighter
C) To increase tensile strength
Rationale: Concrete is strong in compression but weak in tension. Rebar
provides tensile strength.
2. What is the typical water-cement ratio range for structural concrete?
A) 0.1–0.2
B) 0.3–0.5
C) 0.6–0.8
D) 0.9–1.0
B) 0.3–0.5
Rationale: A water-cement ratio of 0.3–0.5 ensures proper hydration while
maintaining strength.
3. Which type of cement is commonly used for general-purpose concrete?
A) Type I
B) Type II
C) Type III
D) Type IV
,A) Type I
Rationale: Type I cement is standard for general construction with normal
strength and setting time.
4. What is slump in concrete testing?
A) Strength measurement
B) Workability measurement
C) Water content measurement
D) Density measurement
B) Workability measurement
Rationale: Slump test measures the consistency or workability of fresh
concrete.
5. What is the recommended curing period for most concrete to reach
adequate strength?
A) 1 day
B) 3 days
C) 7 days
D) 28 days
D) 28 days
Rationale: Concrete continues to gain strength over time; 28 days is
standard for design strength.
6. Which aggregate size is generally used in concrete for reinforced
structural elements?
A) 5–10 mm
B) 10–20 mm
C) 20–40 mm
D) 50–70 mm
B) 10–20 mm
Rationale: Moderate aggregate size ensures proper bonding with rebar and
workability.
7. What is the function of admixtures in concrete?
A) Only to color concrete
, B) Modify properties such as workability, setting time, or durability
C) Replace cement completely
D) Reduce aggregate size
B) Modify properties such as workability, setting time, or durability
Rationale: Admixtures adjust specific concrete characteristics without
replacing cement.
8. Which type of concrete is designed to resist freezing and thawing
cycles?
A) Lightweight concrete
B) Air-entrained concrete
C) High-density concrete
D) Rapid-set concrete
B) Air-entrained concrete
Rationale: Entrained air improves resistance to freeze-thaw damage.
9. What is the primary cause of plastic shrinkage cracks?
A) Excess water
B) Rapid surface drying
C) Poor aggregate
D) Low cement content
B) Rapid surface drying
Rationale: Fast moisture loss before setting causes plastic shrinkage
cracks.
10. Which test is used to measure hardened concrete strength?
A) Slump test
B) Compression test
C) Flow table test
D) Penetration test
B) Compression test
Rationale: Compressive strength is the standard measure for hardened
concrete quality.
