Page 1 of 173
CMEC ACI 1 Concrete Field Testing LATEST
VERSION WITH 300 QUESTIONS AND CORRECT
RATIONALIZED SOLUTIONS JUST RELEASED
THIS YEAR
CMEC ACI 1 Concrete Field Testing Exam — 300 Randomized Practice Questions
Question 1
A field technician arrives at a ready-mix plant to sample concrete from a stationary mixer.
According to ASTM C172, how many portions must be taken to form a representative composite
sample?
A) One portion from the center of the discharge
B) At least two regularly spaced portions from the middle of the discharge
C) Exactly five portions evenly distributed
D) One portion from the start and one from the end
Answer: B
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ASTM C172 requires at least two regularly spaced portions taken during the middle portion of
the discharge, never from the very first or last part, to obtain a representative sample.
Question 2
According to ASTM C172, what is the maximum elapsed time allowed between obtaining the
first and final portions of a composite concrete sample?
A) 5 minutes
B) 10 minutes
C) 15 minutes
D) 20 minutes
Answer: C
The elapsed time between first and final portions must not exceed 15 minutes, as specified in
ASTM C172/C172M.
Question 3
Per ASTM C172, after obtaining the final portion of a composite sample, within how many
minutes must testing for slump, air content, and temperature begin?
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A) 2 minutes
B) 5 minutes
C) 10 minutes
D) 15 minutes
Answer: B
All tests for slump, air content, and temperature must commence within 5 minutes of obtaining
the final portion of the composite sample.
Question 4
According to ASTM C172, what is the minimum size of a composite sample required for strength
tests of freshly mixed concrete?
A) 0.5 ft³ (14 L)
B) 1.0 ft³ (28 L)
C) 2.0 ft³ (56 L)
D) 3.0 ft³ (85 L)
Answer: B
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ASTM C172 specifies a minimum composite sample size of 1.0 ft³ (28 L) for concrete strength
tests.
Question 5
When sampling from a revolving drum truck mixer per ASTM C172, from which portion of the
discharge should samples be taken?
A) The very first discharge
B) The very last discharge
C) The middle portion of the discharge
D) Only the first 10% of the discharge
Answer: C
Samples must be taken from the middle portion of the discharge, avoiding the very beginning
and end to ensure representativeness.
Question 6
A technician has collected a composite sample and needs to transport it to the testing location.
According to ASTM C172, what must be done to the sample before any testing begins?
4
SUCCESS!
CMEC ACI 1 Concrete Field Testing LATEST
VERSION WITH 300 QUESTIONS AND CORRECT
RATIONALIZED SOLUTIONS JUST RELEASED
THIS YEAR
CMEC ACI 1 Concrete Field Testing Exam — 300 Randomized Practice Questions
Question 1
A field technician arrives at a ready-mix plant to sample concrete from a stationary mixer.
According to ASTM C172, how many portions must be taken to form a representative composite
sample?
A) One portion from the center of the discharge
B) At least two regularly spaced portions from the middle of the discharge
C) Exactly five portions evenly distributed
D) One portion from the start and one from the end
Answer: B
1
SUCCESS!
,Page 2 of 173
ASTM C172 requires at least two regularly spaced portions taken during the middle portion of
the discharge, never from the very first or last part, to obtain a representative sample.
Question 2
According to ASTM C172, what is the maximum elapsed time allowed between obtaining the
first and final portions of a composite concrete sample?
A) 5 minutes
B) 10 minutes
C) 15 minutes
D) 20 minutes
Answer: C
The elapsed time between first and final portions must not exceed 15 minutes, as specified in
ASTM C172/C172M.
Question 3
Per ASTM C172, after obtaining the final portion of a composite sample, within how many
minutes must testing for slump, air content, and temperature begin?
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A) 2 minutes
B) 5 minutes
C) 10 minutes
D) 15 minutes
Answer: B
All tests for slump, air content, and temperature must commence within 5 minutes of obtaining
the final portion of the composite sample.
Question 4
According to ASTM C172, what is the minimum size of a composite sample required for strength
tests of freshly mixed concrete?
A) 0.5 ft³ (14 L)
B) 1.0 ft³ (28 L)
C) 2.0 ft³ (56 L)
D) 3.0 ft³ (85 L)
Answer: B
3
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, Page 4 of 173
ASTM C172 specifies a minimum composite sample size of 1.0 ft³ (28 L) for concrete strength
tests.
Question 5
When sampling from a revolving drum truck mixer per ASTM C172, from which portion of the
discharge should samples be taken?
A) The very first discharge
B) The very last discharge
C) The middle portion of the discharge
D) Only the first 10% of the discharge
Answer: C
Samples must be taken from the middle portion of the discharge, avoiding the very beginning
and end to ensure representativeness.
Question 6
A technician has collected a composite sample and needs to transport it to the testing location.
According to ASTM C172, what must be done to the sample before any testing begins?
4
SUCCESS!
