AK Concrete Contractor Exam Questions
and Correct Answers (Verified Answers)
Plus Rationale 2027 Q&A| Instant
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1. Which property of fresh concrete primarily describes its ability to
be placed, consolidated, and finished without excessive
segregation?
a. Density
b. Strength
c. Workability
d. Permeability
Rationale: Workability describes how easily fresh concrete can be
mixed, transported, placed, consolidated, and finished. Proper
workability helps achieve uniform concrete without unnecessary
segregation or excessive water.
, 2. What is the primary purpose of Portland cement in a concrete
mixture?
a. To provide coarse aggregate
b. To reduce aggregate size
c. To bind the aggregates together
d. To prevent all cracking
Rationale: Portland cement reacts chemically with water through
hydration and forms cementitious products that bind the fine and
coarse aggregates into a hardened concrete mass.
3. Which material generally makes up the largest volume of a
conventional concrete mixture?
a. Cement
b. Water
c. Admixtures
d. Aggregate
Rationale: Aggregates commonly constitute the largest portion of
concrete by volume. Their size, grading, shape, and cleanliness
strongly affect workability, strength, durability, and economy.
4. What is the main purpose of a concrete slump test?
,a. To determine compressive strength
b. To determine cement content
c. To measure the consistency of fresh concrete
d. To determine aggregate absorption
Rationale: The slump test provides an indication of the consistency
and relative workability of freshly mixed concrete. It does not directly
measure compressive strength.
5. Adding excessive water to concrete at the jobsite generally has
what effect after the concrete hardens?
a. Increases strength
b. Eliminates shrinkage
c. Reduces strength and durability
d. Eliminates the need for curing
Rationale: Excess water increases the water-cement ratio. After
evaporation, additional capillary voids remain in the hardened
concrete, which can reduce strength and increase permeability.
6. What does the water-cement ratio primarily influence?
a. Form color
b. Reinforcing-bar diameter
, c. Concrete strength and durability
d. Aggregate mineral composition
Rationale: The water-cement ratio is a major factor controlling the
paste structure of concrete. Lower ratios, when properly proportioned
and consolidated, generally produce stronger and less permeable
concrete.
7. Which aggregate is classified as fine aggregate?
a. Gravel
b. Crushed stone retained on a 1-inch sieve
c. Sand
d. Large cobbles
Rationale: Fine aggregate generally consists of sand-sized particles
that pass the appropriate coarse/fine aggregate separation sieve.
Coarse aggregate consists of larger particles such as gravel or crushed
stone.
8. Why should reinforcing steel be supported properly before
concrete placement?
a. To make concrete dry faster
b. To reduce cement hydration
c. To maintain the specified reinforcement position and concrete
and Correct Answers (Verified Answers)
Plus Rationale 2027 Q&A| Instant
Download Pdf
1. Which property of fresh concrete primarily describes its ability to
be placed, consolidated, and finished without excessive
segregation?
a. Density
b. Strength
c. Workability
d. Permeability
Rationale: Workability describes how easily fresh concrete can be
mixed, transported, placed, consolidated, and finished. Proper
workability helps achieve uniform concrete without unnecessary
segregation or excessive water.
, 2. What is the primary purpose of Portland cement in a concrete
mixture?
a. To provide coarse aggregate
b. To reduce aggregate size
c. To bind the aggregates together
d. To prevent all cracking
Rationale: Portland cement reacts chemically with water through
hydration and forms cementitious products that bind the fine and
coarse aggregates into a hardened concrete mass.
3. Which material generally makes up the largest volume of a
conventional concrete mixture?
a. Cement
b. Water
c. Admixtures
d. Aggregate
Rationale: Aggregates commonly constitute the largest portion of
concrete by volume. Their size, grading, shape, and cleanliness
strongly affect workability, strength, durability, and economy.
4. What is the main purpose of a concrete slump test?
,a. To determine compressive strength
b. To determine cement content
c. To measure the consistency of fresh concrete
d. To determine aggregate absorption
Rationale: The slump test provides an indication of the consistency
and relative workability of freshly mixed concrete. It does not directly
measure compressive strength.
5. Adding excessive water to concrete at the jobsite generally has
what effect after the concrete hardens?
a. Increases strength
b. Eliminates shrinkage
c. Reduces strength and durability
d. Eliminates the need for curing
Rationale: Excess water increases the water-cement ratio. After
evaporation, additional capillary voids remain in the hardened
concrete, which can reduce strength and increase permeability.
6. What does the water-cement ratio primarily influence?
a. Form color
b. Reinforcing-bar diameter
, c. Concrete strength and durability
d. Aggregate mineral composition
Rationale: The water-cement ratio is a major factor controlling the
paste structure of concrete. Lower ratios, when properly proportioned
and consolidated, generally produce stronger and less permeable
concrete.
7. Which aggregate is classified as fine aggregate?
a. Gravel
b. Crushed stone retained on a 1-inch sieve
c. Sand
d. Large cobbles
Rationale: Fine aggregate generally consists of sand-sized particles
that pass the appropriate coarse/fine aggregate separation sieve.
Coarse aggregate consists of larger particles such as gravel or crushed
stone.
8. Why should reinforcing steel be supported properly before
concrete placement?
a. To make concrete dry faster
b. To reduce cement hydration
c. To maintain the specified reinforcement position and concrete
