ACI CONCRETE FIELD TESTING
TECHNICIAN ACTUAL EXAM COMPLETE
QUESTIONS AND DETAILED SOLUTIONS
LATEST UPDATE THIS YEAR JUST
RELEASED
1.
A technician arrives on site and is instructed to test
concrete from a ready-mix truck. The discharge has
already begun. According to ASTM requirements, the
sample should be taken:
A. From the first portion of discharge
B. From the last portion of discharge
C. From the middle portion of discharge
D. From any convenient location
Answer: C
Rationale: ASTM C172 requires composite sampling taken
from the middle portion of discharge to ensure the sample
represents the entire batch and avoids segregation or
early/late discharge variations.
2.
,When obtaining a composite sample from a truck mixer,
how many portions are typically required?
A. One
B. Two
C. At least two or more
D. Exactly five
Answer: C
Rationale: ASTM C172 requires multiple portions taken
throughout discharge to form a composite sample,
ensuring representativeness.
3.
While performing a slump test, the technician fails to
moisten the slump cone. What is the potential effect?
A. Increased slump
B. Decreased slump
C. Cone sticking or inaccurate measurement
D. Faster setting time
Answer: C
Rationale: The cone must be clean and damp to prevent
friction or adhesion that could distort the slump
measurement.
,4.
During slump testing, each layer must be consolidated by
rodding:
A. 10 times
B. 15 times
C. 20 times
D. 25 times
Answer: D
Rationale: ASTM C143 specifies 25 roddings per layer to
ensure proper consolidation and eliminate voids.
5.
The slump cone must be lifted in:
A. Less than 1 second
B. 3–7 seconds with steady upward motion
C. 10–15 seconds
D. A jerking motion
Answer: B
Rationale: Controlled removal within 3–7 seconds prevents
disturbance of the concrete mass and ensures accurate
slump measurement.
6.
, If concrete completely collapses after cone removal, this
result should be:
A. Ignored
B. Recorded as zero
C. Reported as collapse
D. Retested automatically
Answer: C
Rationale: Collapse indicates extremely high workability
and must be documented as such under ASTM C143.
7.
Concrete temperature testing is governed by which ASTM
standard?
A. C31
B. C1064
C. C172
D. C138
Answer: B
Rationale: ASTM C1064 specifies procedures for measuring
temperature of freshly mixed concrete.
8.
TECHNICIAN ACTUAL EXAM COMPLETE
QUESTIONS AND DETAILED SOLUTIONS
LATEST UPDATE THIS YEAR JUST
RELEASED
1.
A technician arrives on site and is instructed to test
concrete from a ready-mix truck. The discharge has
already begun. According to ASTM requirements, the
sample should be taken:
A. From the first portion of discharge
B. From the last portion of discharge
C. From the middle portion of discharge
D. From any convenient location
Answer: C
Rationale: ASTM C172 requires composite sampling taken
from the middle portion of discharge to ensure the sample
represents the entire batch and avoids segregation or
early/late discharge variations.
2.
,When obtaining a composite sample from a truck mixer,
how many portions are typically required?
A. One
B. Two
C. At least two or more
D. Exactly five
Answer: C
Rationale: ASTM C172 requires multiple portions taken
throughout discharge to form a composite sample,
ensuring representativeness.
3.
While performing a slump test, the technician fails to
moisten the slump cone. What is the potential effect?
A. Increased slump
B. Decreased slump
C. Cone sticking or inaccurate measurement
D. Faster setting time
Answer: C
Rationale: The cone must be clean and damp to prevent
friction or adhesion that could distort the slump
measurement.
,4.
During slump testing, each layer must be consolidated by
rodding:
A. 10 times
B. 15 times
C. 20 times
D. 25 times
Answer: D
Rationale: ASTM C143 specifies 25 roddings per layer to
ensure proper consolidation and eliminate voids.
5.
The slump cone must be lifted in:
A. Less than 1 second
B. 3–7 seconds with steady upward motion
C. 10–15 seconds
D. A jerking motion
Answer: B
Rationale: Controlled removal within 3–7 seconds prevents
disturbance of the concrete mass and ensures accurate
slump measurement.
6.
, If concrete completely collapses after cone removal, this
result should be:
A. Ignored
B. Recorded as zero
C. Reported as collapse
D. Retested automatically
Answer: C
Rationale: Collapse indicates extremely high workability
and must be documented as such under ASTM C143.
7.
Concrete temperature testing is governed by which ASTM
standard?
A. C31
B. C1064
C. C172
D. C138
Answer: B
Rationale: ASTM C1064 specifies procedures for measuring
temperature of freshly mixed concrete.
8.
