C-5 CONCRETE CONTRACTOR EXAM – QUESTIONS AND ANSWERS |
VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES |
GUARANTEED PASS | LATEST EXAM UPDATE
Core Domains
Scope of Work and Licensing Regulations
Formwork Design and Construction
Reinforcement Placement and Standards
Concrete Mix Design and Testing
Placement, Finishing, and Curing Procedures
Job Site Safety and OSHA Compliance (29 CFR 1926 Subpart Q)
Estimating, Plan Reading, and Project Management
Introduction
This examination is designed to assess the competency of candidates seeking
licensure as C-5 Concrete Contractors. It evaluates the knowledge, skills, and
judgment required to safely and legally perform concrete construction activities,
including formwork, reinforcement, placement, finishing, and cutting. The exam
utilizes multiple-choice and scenario-based questions to simulate real-world
challenges encountered on the job site. Emphasis is placed on practical
application, adherence to regulatory standards, and critical decision-making to
ensure structural integrity, worker safety, and compliance with trade-specific
codes and ethics.
SECTION ONE: QUESTIONS 1–50
1. According to the scope of work for a C-5 license, which of the following
activities is authorized without additional specialty classification?
A. Installing electrical conduit within a concrete slab
,B. Applying concrete sealants and waterproofing products
C. Structural welding of steel beams
D. Plumbing rough-in beneath a slab-on-grade
🟢 Correct Answer: B. Applying concrete sealants and other waterproofing
products
🔴 Rationale: The C-5 classification explicitly authorizes the application of
sealants and waterproofing products as an integral part of concrete
construction, whereas electrical, structural steel, and plumbing work fall under
separate trades.
2. When constructing formwork for a elevated slab, what is the primary
purpose of installing shoring equipment?
A. To provide a walking surface for workers
B. To support the vertical and lateral loads until the concrete gains sufficient
strength
C. To permanently reinforce the concrete slab
D. To prevent the loss of cement paste
🟢 Correct Answer: B. To support the vertical and lateral loads until the
concrete gains sufficient strength
🔴 Rationale: Shoring is a temporary structural support system designed to
carry the weight of the fresh concrete, formwork, and construction loads until
the concrete can support itself.
3. A contractor is preparing to place concrete during hot weather. Which
action is most critical to prevent plastic shrinkage cracking?
A. Adding extra water to the mix to increase workability
B. Using ice to cool the concrete and monitoring evaporation rates
C. Increasing the cement content to accelerate set time
D. Placing the concrete in direct sunlight to speed curing
🟢 Correct Answer: B. Using ice to cool the concrete and monitoring
,evaporation rates
🔴 Rationale: Hot weather accelerates moisture loss from the surface, leading
to plastic shrinkage. Cooling the mix and mitigating evaporation are standard
preventative measures.
4. What is the standard requirement for the minimum concrete cover over
reinforcing steel when the concrete is cast against and permanently exposed
to earth?
A. 1 inch
B. 1.5 inches
C. 3 inches
D. 4 inches
🟢 Correct Answer: C. 3 inches
🔴 Rationale: ACI 318 requires a minimum cover of 3 inches for concrete cast
against and permanently exposed to earth to protect the reinforcement from
corrosion and physical damage.
5. Which type of joint is intentionally created to control the location of
cracking due to shrinkage and temperature changes?
A. Construction joint
B. Expansion joint
C. Control joint
D. Isolation joint
🟢 Correct Answer: C. Control joint
🔴 Rationale: Control joints provide a weakened plane in the concrete slab,
forcing cracks to occur at a predetermined, straight line rather than randomly
across the surface.
6. Under OSHA regulations (29 CFR 1926 Subpart Q), what is required for
protruding reinforcing steel that could create an impalement hazard?
A. It must be painted a bright color
, B. It must be bent over immediately
C. It must be guarded to eliminate the hazard
D. It must be removed before the end of the shift
🟢 Correct Answer: C. It must be guarded to eliminate the hazard
🔴 Rationale: OSHA mandates that all protruding reinforcing steel, onto which
employees could fall, must be guarded to eliminate the impalement hazard.
7. What does the term "slump" measure in a concrete mix?
A. The compressive strength of the concrete
B. The consistency and workability of fresh concrete
C. The amount of entrained air in the mix
D. The rate of hydration
🟢 Correct Answer: B. The consistency and workability of fresh concrete
🔴 Rationale: The slump test (ASTM C143) is a standard field test used to
determine the consistency and workability of a concrete mixture.
8. When placing concrete in a deep wall form, what is the primary risk of
allowing the concrete to free-fall from a significant height?
A. Segregation of the coarse aggregate from the mortar
B. Excessive air entrainment
C. Accelerated curing
D. Increased form pressure
🟢 Correct Answer: A. Segregation of the coarse aggregate from the mortar
🔴 Rationale: Dropping concrete from excessive heights causes the heavier
aggregate particles to separate from the cement paste, leading to segregation
and honeycombing.
9. Which ASTM standard specification covers deformed and plain carbon-
steel bars for concrete reinforcement?
A. ASTM C150
B. ASTM A615
VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES |
GUARANTEED PASS | LATEST EXAM UPDATE
Core Domains
Scope of Work and Licensing Regulations
Formwork Design and Construction
Reinforcement Placement and Standards
Concrete Mix Design and Testing
Placement, Finishing, and Curing Procedures
Job Site Safety and OSHA Compliance (29 CFR 1926 Subpart Q)
Estimating, Plan Reading, and Project Management
Introduction
This examination is designed to assess the competency of candidates seeking
licensure as C-5 Concrete Contractors. It evaluates the knowledge, skills, and
judgment required to safely and legally perform concrete construction activities,
including formwork, reinforcement, placement, finishing, and cutting. The exam
utilizes multiple-choice and scenario-based questions to simulate real-world
challenges encountered on the job site. Emphasis is placed on practical
application, adherence to regulatory standards, and critical decision-making to
ensure structural integrity, worker safety, and compliance with trade-specific
codes and ethics.
SECTION ONE: QUESTIONS 1–50
1. According to the scope of work for a C-5 license, which of the following
activities is authorized without additional specialty classification?
A. Installing electrical conduit within a concrete slab
,B. Applying concrete sealants and waterproofing products
C. Structural welding of steel beams
D. Plumbing rough-in beneath a slab-on-grade
🟢 Correct Answer: B. Applying concrete sealants and other waterproofing
products
🔴 Rationale: The C-5 classification explicitly authorizes the application of
sealants and waterproofing products as an integral part of concrete
construction, whereas electrical, structural steel, and plumbing work fall under
separate trades.
2. When constructing formwork for a elevated slab, what is the primary
purpose of installing shoring equipment?
A. To provide a walking surface for workers
B. To support the vertical and lateral loads until the concrete gains sufficient
strength
C. To permanently reinforce the concrete slab
D. To prevent the loss of cement paste
🟢 Correct Answer: B. To support the vertical and lateral loads until the
concrete gains sufficient strength
🔴 Rationale: Shoring is a temporary structural support system designed to
carry the weight of the fresh concrete, formwork, and construction loads until
the concrete can support itself.
3. A contractor is preparing to place concrete during hot weather. Which
action is most critical to prevent plastic shrinkage cracking?
A. Adding extra water to the mix to increase workability
B. Using ice to cool the concrete and monitoring evaporation rates
C. Increasing the cement content to accelerate set time
D. Placing the concrete in direct sunlight to speed curing
🟢 Correct Answer: B. Using ice to cool the concrete and monitoring
,evaporation rates
🔴 Rationale: Hot weather accelerates moisture loss from the surface, leading
to plastic shrinkage. Cooling the mix and mitigating evaporation are standard
preventative measures.
4. What is the standard requirement for the minimum concrete cover over
reinforcing steel when the concrete is cast against and permanently exposed
to earth?
A. 1 inch
B. 1.5 inches
C. 3 inches
D. 4 inches
🟢 Correct Answer: C. 3 inches
🔴 Rationale: ACI 318 requires a minimum cover of 3 inches for concrete cast
against and permanently exposed to earth to protect the reinforcement from
corrosion and physical damage.
5. Which type of joint is intentionally created to control the location of
cracking due to shrinkage and temperature changes?
A. Construction joint
B. Expansion joint
C. Control joint
D. Isolation joint
🟢 Correct Answer: C. Control joint
🔴 Rationale: Control joints provide a weakened plane in the concrete slab,
forcing cracks to occur at a predetermined, straight line rather than randomly
across the surface.
6. Under OSHA regulations (29 CFR 1926 Subpart Q), what is required for
protruding reinforcing steel that could create an impalement hazard?
A. It must be painted a bright color
, B. It must be bent over immediately
C. It must be guarded to eliminate the hazard
D. It must be removed before the end of the shift
🟢 Correct Answer: C. It must be guarded to eliminate the hazard
🔴 Rationale: OSHA mandates that all protruding reinforcing steel, onto which
employees could fall, must be guarded to eliminate the impalement hazard.
7. What does the term "slump" measure in a concrete mix?
A. The compressive strength of the concrete
B. The consistency and workability of fresh concrete
C. The amount of entrained air in the mix
D. The rate of hydration
🟢 Correct Answer: B. The consistency and workability of fresh concrete
🔴 Rationale: The slump test (ASTM C143) is a standard field test used to
determine the consistency and workability of a concrete mixture.
8. When placing concrete in a deep wall form, what is the primary risk of
allowing the concrete to free-fall from a significant height?
A. Segregation of the coarse aggregate from the mortar
B. Excessive air entrainment
C. Accelerated curing
D. Increased form pressure
🟢 Correct Answer: A. Segregation of the coarse aggregate from the mortar
🔴 Rationale: Dropping concrete from excessive heights causes the heavier
aggregate particles to separate from the cement paste, leading to segregation
and honeycombing.
9. Which ASTM standard specification covers deformed and plain carbon-
steel bars for concrete reinforcement?
A. ASTM C150
B. ASTM A615
