LATEST ACI CONCRETE FLATWORK
FINISHER CERTIFICATION EXAM | Q&A
WITH RATIONALES
1. Which type of Portland cement is most commonly
used for residential slab-on-grade work because of
its moderate heat of hydration?
A) Type I
B) Type II
C) Type III
D) Type V
Correct answer: A
Rationale: Type I cement is the standard "general-
purpose" cement with a normal heat of hydration,
making it suitable for most residential flatwork. Type
II is used where moderate sulfate resistance is
required, Type III is high-early-strength, and Type V
is high sulfate resistant.
2. The water-cement ratio primarily controls which
property of hardened concrete?
A) Workability
,B) Compressive strength
C) Air content
D) Color
Correct answer: B
Rationale: A lower w/c ratio yields higher
compressive strength, while a higher ratio reduces
strength and durability.
3. Which aggregate size is typically limited to ¾-inch
(19 mm) maximum for interior flatwork?
A) Fine aggregate
B) Coarse aggregate
C) Recycled aggregate
D) Lightweight aggregate
Correct answer: B
Rationale: Coarse aggregate for interior flatwork is
limited to ¾-inch to ensure proper finishability and
reduce surface voids.
4. The primary purpose of an air-entraining
admixture in concrete for cold climates is to:
,A) Increase early strength
B) Reduce water demand
C) Provide freeze-thaw resistance
D) Accelerate setting time
Correct answer: C
Rationale: Air-entraining admixtures create
microscopic air bubbles that relieve internal
pressure during freeze-thaw cycles, preventing
scaling and cracking.
5. A concrete mixture has a target slump of 4 inches.
If the measured slump is 2 inches, what should the
finisher anticipate?
A) The concrete will be easier to finish
B) The concrete will be more difficult to place and
finish, and may require additional water or a
superplasticizer
C) The concrete will have higher strength
D) The concrete will set faster
Correct answer: B
Rationale: Low slump concrete is stiffer and harder
to work with, requiring more effort to place,
, consolidate, and finish. Additional water should not
be added without approval as it will reduce strength.
6. The recommended maximum time between adding
water at the plant and completing discharge of the
concrete at the jobsite is:
A) 30 minutes
B) 1 hour
C) 1.5 hours
D) 2 hours
Correct answer: C
Rationale: ACI and many specifications require that
concrete be discharged within 1.5 hours (90
minutes) after water is added to prevent loss of
workability and setting issues.
7. When concrete will be discharged directly from
the truck chute into forms, truck arrivals should
typically be spaced about how many minutes apart?
A) 5 minutes
B) 10 minutes
C) 15 minutes
FINISHER CERTIFICATION EXAM | Q&A
WITH RATIONALES
1. Which type of Portland cement is most commonly
used for residential slab-on-grade work because of
its moderate heat of hydration?
A) Type I
B) Type II
C) Type III
D) Type V
Correct answer: A
Rationale: Type I cement is the standard "general-
purpose" cement with a normal heat of hydration,
making it suitable for most residential flatwork. Type
II is used where moderate sulfate resistance is
required, Type III is high-early-strength, and Type V
is high sulfate resistant.
2. The water-cement ratio primarily controls which
property of hardened concrete?
A) Workability
,B) Compressive strength
C) Air content
D) Color
Correct answer: B
Rationale: A lower w/c ratio yields higher
compressive strength, while a higher ratio reduces
strength and durability.
3. Which aggregate size is typically limited to ¾-inch
(19 mm) maximum for interior flatwork?
A) Fine aggregate
B) Coarse aggregate
C) Recycled aggregate
D) Lightweight aggregate
Correct answer: B
Rationale: Coarse aggregate for interior flatwork is
limited to ¾-inch to ensure proper finishability and
reduce surface voids.
4. The primary purpose of an air-entraining
admixture in concrete for cold climates is to:
,A) Increase early strength
B) Reduce water demand
C) Provide freeze-thaw resistance
D) Accelerate setting time
Correct answer: C
Rationale: Air-entraining admixtures create
microscopic air bubbles that relieve internal
pressure during freeze-thaw cycles, preventing
scaling and cracking.
5. A concrete mixture has a target slump of 4 inches.
If the measured slump is 2 inches, what should the
finisher anticipate?
A) The concrete will be easier to finish
B) The concrete will be more difficult to place and
finish, and may require additional water or a
superplasticizer
C) The concrete will have higher strength
D) The concrete will set faster
Correct answer: B
Rationale: Low slump concrete is stiffer and harder
to work with, requiring more effort to place,
, consolidate, and finish. Additional water should not
be added without approval as it will reduce strength.
6. The recommended maximum time between adding
water at the plant and completing discharge of the
concrete at the jobsite is:
A) 30 minutes
B) 1 hour
C) 1.5 hours
D) 2 hours
Correct answer: C
Rationale: ACI and many specifications require that
concrete be discharged within 1.5 hours (90
minutes) after water is added to prevent loss of
workability and setting issues.
7. When concrete will be discharged directly from
the truck chute into forms, truck arrivals should
typically be spaced about how many minutes apart?
A) 5 minutes
B) 10 minutes
C) 15 minutes
