ACI Concrete Field Testing Technician
ACI CONCRETE FIELD -TESTING TECHNICIAN COMPLETE EXAM
QUESTIONS AND 100% VERIFIED ANSWERS (2026/2027) PASS
GUARANTEE
Q1. According to ASTM C172, the minimum size of a composite
sample of fresh concrete should be at least:
A. 1 ft³ (28 L) B. 1.5 ft³ (42 L)
C. ½ ft³ (14 L) D. 2 ft³ (57 L)
Answer: A | ASTM C172 requires the composite sample to be at least
1 ft³ (28 L) to ensure it is representative.
Q2. When sampling from a revolving drum truck mixer, samples
should be taken at how many regularly spaced intervals during
discharge?
A. At least 2 B. At least 3
C. At least 5 D. Just once at midpoint
Answer: A | ASTM C172 requires at least two portions taken at
regularly spaced intervals during the middle portion of the load.
Q3. Sampling of concrete from a truck mixer should NOT be done
from:
A. The middle portion of the batch B. The very first or last tenth of
the load
C. The 30th percentile of discharge D. After adding water on site
Answer: B | The first and last tenth of the load are not representative
and should be discarded per ASTM C172.
Q4. After obtaining a composite sample, all testing should begin
within:
A. 5 minutes B. 10 minutes
C. 15 minutes D. 30 minutes
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, ACI Concrete Field Testing Technician
Answer: A | All tests should begin within 5 minutes of obtaining the
composite sample per ASTM C172.
Q5. Which ASTM standard covers sampling freshly mixed concrete?
A. ASTM C31 B. ASTM C138
C. ASTM C172 D. ASTM C143
Answer: C | ASTM C172 is the standard practice for sampling freshly
mixed concrete.
Q6. The composite sample should be remixed with a shovel for at
least how many strokes before testing?
A. 3 B. 5
C. 10 D. 15
Answer: A | The sample should be remixed at the sampling location
with at least 3 shovel strokes before being placed in containers for
testing.
Q7. Samples taken from a stationary mixer should be obtained from
at least:
A. One location B. Two or more regularly spaced
portions
C. Three consecutive loads D. The middle and end only
Answer: B | ASTM C172 requires representative samples from two or
more regularly spaced intervals during discharge.
Q8. The maximum time allowed between obtaining the first and final
portions of a composite sample is:
A. 5 minutes B. 10 minutes
C. 15 minutes D. 20 minutes
Answer: C | The entire composite sample must be obtained within 15
minutes (ASTM C172).
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, ACI Concrete Field Testing Technician
Q9. When sampling concrete from a conveyor belt, the sample is
best collected using a:
A. Bucket B. Sample pan across the full
width
C. Trowel D. Pipe tube
Answer: B | A pan that spans the full width of the belt is used so the
entire cross-section is captured.
Q10. Concrete should NOT be sampled from:
A. A transit mixer B. An open-top truck
C. A pump discharge D. The beginning 10% of the load
Answer: D | The first and last 10% of any batch should not be sampled
as they are not representative (ASTM C172).
Q11. Which of the following is NOT a valid sampling location per
ASTM C172?
A. Stationary mixer B. Agitating truck
C. Pump discharge line D. Wheelbarrow after 60 min
Answer: D | Concrete that has sat for 60 minutes may be outside
acceptable time limits and is not a valid sampling location.
Q12. How should the sample be protected after collection?
A. Left uncovered in shade B. Covered to prevent
evaporation and kept out of direct
sun
C. Stored in refrigerator D. Mixed continuously
Answer: B | The sample must be protected from direct sun and wind to
prevent evaporation and premature stiffening.
Q13. The sampling receptacle should be:
A. Absorbent wood B. Non-absorbent, clean, and
damp
C. Dry metal D. Paper lined
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, ACI Concrete Field Testing Technician
Answer: B | The container must be non-absorbent, clean, and slightly
damp to avoid removing moisture from the sample.
Q14. Who is responsible for ensuring the concrete sample is
properly obtained at the job site?
A. The truck driver B. The ACI-certified field testing
technician
C. The general contractor D. The mix design engineer
Answer: B | The ACI-certified field testing technician is responsible for
proper sampling and testing on site.
Q15. When sampling from a pump discharge, where should the
sample be taken?
A. At the pump inlet B. At the hose end (point of
discharge)
C. From the hopper D. From the return line
Answer: B | For pumped concrete, the sample is taken at the point of
discharge from the hose.
Q16. The composite sample must be transported and testing must
start within:
A. 2 minutes B. 5 minutes
C. 10 minutes D. 20 minutes
Answer: B | Testing must begin within 5 minutes after obtaining the
composite sample (ASTM C172).
Q17. ASTM C172 sampling is applicable to concrete with a
maximum aggregate size up to:
A. 1 inch (25 mm) B. 1½ inch (37.5 mm)
C. 2 inch (50 mm) D. 3 inch (75 mm)
Answer: B | ASTM C172 is generally applicable to concrete with
aggregates up to 1½ in (37.5 mm) nominal maximum size.
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ACI CONCRETE FIELD -TESTING TECHNICIAN COMPLETE EXAM
QUESTIONS AND 100% VERIFIED ANSWERS (2026/2027) PASS
GUARANTEE
Q1. According to ASTM C172, the minimum size of a composite
sample of fresh concrete should be at least:
A. 1 ft³ (28 L) B. 1.5 ft³ (42 L)
C. ½ ft³ (14 L) D. 2 ft³ (57 L)
Answer: A | ASTM C172 requires the composite sample to be at least
1 ft³ (28 L) to ensure it is representative.
Q2. When sampling from a revolving drum truck mixer, samples
should be taken at how many regularly spaced intervals during
discharge?
A. At least 2 B. At least 3
C. At least 5 D. Just once at midpoint
Answer: A | ASTM C172 requires at least two portions taken at
regularly spaced intervals during the middle portion of the load.
Q3. Sampling of concrete from a truck mixer should NOT be done
from:
A. The middle portion of the batch B. The very first or last tenth of
the load
C. The 30th percentile of discharge D. After adding water on site
Answer: B | The first and last tenth of the load are not representative
and should be discarded per ASTM C172.
Q4. After obtaining a composite sample, all testing should begin
within:
A. 5 minutes B. 10 minutes
C. 15 minutes D. 30 minutes
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, ACI Concrete Field Testing Technician
Answer: A | All tests should begin within 5 minutes of obtaining the
composite sample per ASTM C172.
Q5. Which ASTM standard covers sampling freshly mixed concrete?
A. ASTM C31 B. ASTM C138
C. ASTM C172 D. ASTM C143
Answer: C | ASTM C172 is the standard practice for sampling freshly
mixed concrete.
Q6. The composite sample should be remixed with a shovel for at
least how many strokes before testing?
A. 3 B. 5
C. 10 D. 15
Answer: A | The sample should be remixed at the sampling location
with at least 3 shovel strokes before being placed in containers for
testing.
Q7. Samples taken from a stationary mixer should be obtained from
at least:
A. One location B. Two or more regularly spaced
portions
C. Three consecutive loads D. The middle and end only
Answer: B | ASTM C172 requires representative samples from two or
more regularly spaced intervals during discharge.
Q8. The maximum time allowed between obtaining the first and final
portions of a composite sample is:
A. 5 minutes B. 10 minutes
C. 15 minutes D. 20 minutes
Answer: C | The entire composite sample must be obtained within 15
minutes (ASTM C172).
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, ACI Concrete Field Testing Technician
Q9. When sampling concrete from a conveyor belt, the sample is
best collected using a:
A. Bucket B. Sample pan across the full
width
C. Trowel D. Pipe tube
Answer: B | A pan that spans the full width of the belt is used so the
entire cross-section is captured.
Q10. Concrete should NOT be sampled from:
A. A transit mixer B. An open-top truck
C. A pump discharge D. The beginning 10% of the load
Answer: D | The first and last 10% of any batch should not be sampled
as they are not representative (ASTM C172).
Q11. Which of the following is NOT a valid sampling location per
ASTM C172?
A. Stationary mixer B. Agitating truck
C. Pump discharge line D. Wheelbarrow after 60 min
Answer: D | Concrete that has sat for 60 minutes may be outside
acceptable time limits and is not a valid sampling location.
Q12. How should the sample be protected after collection?
A. Left uncovered in shade B. Covered to prevent
evaporation and kept out of direct
sun
C. Stored in refrigerator D. Mixed continuously
Answer: B | The sample must be protected from direct sun and wind to
prevent evaporation and premature stiffening.
Q13. The sampling receptacle should be:
A. Absorbent wood B. Non-absorbent, clean, and
damp
C. Dry metal D. Paper lined
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, ACI Concrete Field Testing Technician
Answer: B | The container must be non-absorbent, clean, and slightly
damp to avoid removing moisture from the sample.
Q14. Who is responsible for ensuring the concrete sample is
properly obtained at the job site?
A. The truck driver B. The ACI-certified field testing
technician
C. The general contractor D. The mix design engineer
Answer: B | The ACI-certified field testing technician is responsible for
proper sampling and testing on site.
Q15. When sampling from a pump discharge, where should the
sample be taken?
A. At the pump inlet B. At the hose end (point of
discharge)
C. From the hopper D. From the return line
Answer: B | For pumped concrete, the sample is taken at the point of
discharge from the hose.
Q16. The composite sample must be transported and testing must
start within:
A. 2 minutes B. 5 minutes
C. 10 minutes D. 20 minutes
Answer: B | Testing must begin within 5 minutes after obtaining the
composite sample (ASTM C172).
Q17. ASTM C172 sampling is applicable to concrete with a
maximum aggregate size up to:
A. 1 inch (25 mm) B. 1½ inch (37.5 mm)
C. 2 inch (50 mm) D. 3 inch (75 mm)
Answer: B | ASTM C172 is generally applicable to concrete with
aggregates up to 1½ in (37.5 mm) nominal maximum size.
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