Nevada C-5 Concrete Contractor Exam
2026/2027 | NSCB & PSI Trade Exam Study
Guide | Practice Questions, Correct Answers
& Detailed Rationales | Just Released PDF
NEVADA C-5 CONCRETE CONTRACTOR EXAM 2026/2027
PRACTICE QUESTIONS, CORRECT ANSWERS & DETAILED RATIONALES
====================================================================
============
DOCUMENT OVERVIEW & STUDY GUIDANCE:
• This comprehensive study guide contains 200 practice questions with verified
correct answers and detailed rationales designed to simulate the actual Nevada C-5
Concrete Contractor Exam format—use this material to identify knowledge gaps
and build confidence across all tested domains.
• Study strategically by working through questions systematically, reviewing
rationales for both correct and incorrect answers to understand the reasoning, and
repeating challenging sections to reinforce mastery before test day.
====================================================================
============
SECTION 1: CONCRETE MATERIALS & PROPERTIES
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============
1. Which of the following is the primary binding agent in Portland cement
concrete?
A) Sand
B) Aggregate
C) Portland cement
D) Water
E) Air
✓ CORRECT ANSWER: C) Portland cement
,Rationale: Portland cement acts as the binding agent that, when mixed with water,
creates a paste that binds aggregate particles together. This hydration process is
fundamental to concrete formation. While water, aggregate, and sand are essential
components, they do not serve as the primary binder. Air is typically an unintended
void or intentionally entrained for durability.
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============
2. What is the typical water-to-cement ratio range for most standard concrete
mixes?
A) 0.2 to 0.4
B) 0.4 to 0.65
C) 0.8 to 1.0
D) 1.2 to 1.5
E) 1.8 to 2.2
✓ CORRECT ANSWER: B) 0.4 to 0.65
Rationale: The typical water-to-cement (w/c) ratio for standard concrete mixtures
ranges from 0.4 to 0.65. Ratios below 0.4 can result in difficult workability and
incomplete hydration, while ratios above 0.65 tend to produce weaker concrete
with higher permeability. The specific ratio selected depends on the desired
compressive strength, durability, and workability requirements.
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============
3. Which aggregate size is classified as coarse aggregate in concrete?
A) Particles passing the #4 sieve
B) Particles retained on the #4 sieve
C) All particles smaller than 1/4 inch
D) All particles smaller than sand
E) Particles passing the #8 sieve
✓ CORRECT ANSWER: B) Particles retained on the #4 sieve
,Rationale: According to ASTM C33 (Standard Specification for Concrete Aggregates),
coarse aggregate consists of particles larger than or retained on the #4 sieve
(approximately 4.75 mm). Fine aggregate (sand) passes the #4 sieve but is retained
on the #200 sieve. This distinction is critical for mix design and quality control.
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============
4. What is the primary purpose of air entrainment in concrete?
A) To increase compressive strength
B) To improve freeze-thaw resistance and workability
C) To reduce water demand
D) To increase density
E) To accelerate setting time
✓ CORRECT ANSWER: B) To improve freeze-thaw resistance and workability
Rationale: Air entrainment introduces small, stable air bubbles (typically 4-8% by
volume) into concrete. These microscopic air voids provide relief for water pressure
during freeze-thaw cycles, significantly improving durability in cold climates. While
air entrainment also improves workability, it actually reduces compressive strength
slightly and decreases density. It does not reduce water demand or accelerate
setting.
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============
5. Which of the following best describes the hydration process in Portland
cement?
A) A physical process where cement particles dissolve in water
B) A chemical reaction where cement compounds combine with water to form gel
C) Evaporation of water from the concrete mixture
D) Crystallization of sand particles
E) Decomposition of cement at high temperatures
✓ CORRECT ANSWER: B) A chemical reaction where cement compounds
combine with water to form gel
, Rationale: Cement hydration is a complex chemical process where Portland cement
compounds (C3S, C2S, C3A, C4AF) react with water to form calcium silicate hydrate
(C-S-H) gel and other products. This exothermic reaction is what gives concrete its
strength and durability. It is not a simple dissolution or physical process.
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============
6. What does a high slump value indicate about freshly mixed concrete?
A) High water content and increased workability
B) Low water content and decreased workability
C) High cement content and reduced flowability
D) Improved durability and strength
E) Rapid setting and early strength gain
✓ CORRECT ANSWER: A) High water content and increased workability
Rationale: Slump measures the horizontal and vertical spread of a concrete sample
after the form is lifted. A higher slump (typically 4-8 inches for standard concrete)
indicates a wetter mix with better flowability and workability. However, excessive
slump may compromise strength and durability. Low slump (stiff concrete)
indicates drier mixtures with reduced workability.
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============
7. Which type of Portland cement is recommended for use in marine
environments?
A) Type I - General Purpose
B) Type II - Moderate Sulfate Resistance
C) Type III - High Early Strength
D) Type V - High Sulfate Resistance
E) Type IV - Low Heat
✓ CORRECT ANSWER: D) Type V - High Sulfate Resistance
Rationale: Type V Portland cement is specifically formulated to resist sulfate attack,
making it ideal for marine environments and other locations with high sulfate
2026/2027 | NSCB & PSI Trade Exam Study
Guide | Practice Questions, Correct Answers
& Detailed Rationales | Just Released PDF
NEVADA C-5 CONCRETE CONTRACTOR EXAM 2026/2027
PRACTICE QUESTIONS, CORRECT ANSWERS & DETAILED RATIONALES
====================================================================
============
DOCUMENT OVERVIEW & STUDY GUIDANCE:
• This comprehensive study guide contains 200 practice questions with verified
correct answers and detailed rationales designed to simulate the actual Nevada C-5
Concrete Contractor Exam format—use this material to identify knowledge gaps
and build confidence across all tested domains.
• Study strategically by working through questions systematically, reviewing
rationales for both correct and incorrect answers to understand the reasoning, and
repeating challenging sections to reinforce mastery before test day.
====================================================================
============
SECTION 1: CONCRETE MATERIALS & PROPERTIES
====================================================================
============
1. Which of the following is the primary binding agent in Portland cement
concrete?
A) Sand
B) Aggregate
C) Portland cement
D) Water
E) Air
✓ CORRECT ANSWER: C) Portland cement
,Rationale: Portland cement acts as the binding agent that, when mixed with water,
creates a paste that binds aggregate particles together. This hydration process is
fundamental to concrete formation. While water, aggregate, and sand are essential
components, they do not serve as the primary binder. Air is typically an unintended
void or intentionally entrained for durability.
====================================================================
============
2. What is the typical water-to-cement ratio range for most standard concrete
mixes?
A) 0.2 to 0.4
B) 0.4 to 0.65
C) 0.8 to 1.0
D) 1.2 to 1.5
E) 1.8 to 2.2
✓ CORRECT ANSWER: B) 0.4 to 0.65
Rationale: The typical water-to-cement (w/c) ratio for standard concrete mixtures
ranges from 0.4 to 0.65. Ratios below 0.4 can result in difficult workability and
incomplete hydration, while ratios above 0.65 tend to produce weaker concrete
with higher permeability. The specific ratio selected depends on the desired
compressive strength, durability, and workability requirements.
====================================================================
============
3. Which aggregate size is classified as coarse aggregate in concrete?
A) Particles passing the #4 sieve
B) Particles retained on the #4 sieve
C) All particles smaller than 1/4 inch
D) All particles smaller than sand
E) Particles passing the #8 sieve
✓ CORRECT ANSWER: B) Particles retained on the #4 sieve
,Rationale: According to ASTM C33 (Standard Specification for Concrete Aggregates),
coarse aggregate consists of particles larger than or retained on the #4 sieve
(approximately 4.75 mm). Fine aggregate (sand) passes the #4 sieve but is retained
on the #200 sieve. This distinction is critical for mix design and quality control.
====================================================================
============
4. What is the primary purpose of air entrainment in concrete?
A) To increase compressive strength
B) To improve freeze-thaw resistance and workability
C) To reduce water demand
D) To increase density
E) To accelerate setting time
✓ CORRECT ANSWER: B) To improve freeze-thaw resistance and workability
Rationale: Air entrainment introduces small, stable air bubbles (typically 4-8% by
volume) into concrete. These microscopic air voids provide relief for water pressure
during freeze-thaw cycles, significantly improving durability in cold climates. While
air entrainment also improves workability, it actually reduces compressive strength
slightly and decreases density. It does not reduce water demand or accelerate
setting.
====================================================================
============
5. Which of the following best describes the hydration process in Portland
cement?
A) A physical process where cement particles dissolve in water
B) A chemical reaction where cement compounds combine with water to form gel
C) Evaporation of water from the concrete mixture
D) Crystallization of sand particles
E) Decomposition of cement at high temperatures
✓ CORRECT ANSWER: B) A chemical reaction where cement compounds
combine with water to form gel
, Rationale: Cement hydration is a complex chemical process where Portland cement
compounds (C3S, C2S, C3A, C4AF) react with water to form calcium silicate hydrate
(C-S-H) gel and other products. This exothermic reaction is what gives concrete its
strength and durability. It is not a simple dissolution or physical process.
====================================================================
============
6. What does a high slump value indicate about freshly mixed concrete?
A) High water content and increased workability
B) Low water content and decreased workability
C) High cement content and reduced flowability
D) Improved durability and strength
E) Rapid setting and early strength gain
✓ CORRECT ANSWER: A) High water content and increased workability
Rationale: Slump measures the horizontal and vertical spread of a concrete sample
after the form is lifted. A higher slump (typically 4-8 inches for standard concrete)
indicates a wetter mix with better flowability and workability. However, excessive
slump may compromise strength and durability. Low slump (stiff concrete)
indicates drier mixtures with reduced workability.
====================================================================
============
7. Which type of Portland cement is recommended for use in marine
environments?
A) Type I - General Purpose
B) Type II - Moderate Sulfate Resistance
C) Type III - High Early Strength
D) Type V - High Sulfate Resistance
E) Type IV - Low Heat
✓ CORRECT ANSWER: D) Type V - High Sulfate Resistance
Rationale: Type V Portland cement is specifically formulated to resist sulfate attack,
making it ideal for marine environments and other locations with high sulfate
