ACI- Concrete Field-Testing Technician -
Grade 1 Requires a working knowledge of
seven basic field tests on freshly mixed
concrete. ASTM test methods and practices
updated
Q1. Start molding specimens for strength tests within 30 minutes after fabricating the composite sample.
II! II! II! II! II! II! II! II! II! II! II! II! II! II!
A. True II!
B. False - Correct Answers B. False
II! II! II! II! II! II! II! II! II! II! II!
II! ASTM C172 -Para (4.1.2) - Start molding.
II! II! II! II! II! II!
specimens for strength tests within 15 min after fabricating the II! II! II! II! II! II! II! II! II!
composite sample. II!
II! Q2. The maximum allowable time between obtaining the first and last portions of the composite sample
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
II! may not exceed 5 minutes.
II! II! II! II!
A. True II!
B. False - Correct Answers B. False
II! II! II! II! II! II! II! II! II! II! II!
ASTM C172 - Para (4.1)- The elapsed time shall not exceed 15 min. between obtaining the first and final
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
portions of the composite sample.
II! II! II! II! II!
II! Q3. The composite concrete sample must be protected from sun, wind, contamination and rapid
II! II! II! II! II! II! II! II! II! II! II! II! II!
II! evaporation.
,A. True II!
B. False - Correct Answers A. True
II! II! II! II! II! II! II! II! II! II! II!
ASTM C172 - Para (4.1.2) II! II! II! II!
II! Q4. If the concrete contains aggregates larger than those that are appropriate for a size of mold or
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
II! equipment used, the sample should be wet sieved before making the test.
II! II! II! II! II! II! II! II! II! II! II!
A. True II!
B. False - Correct Answers A. True
II! II! II! II! II! II! II! II! II! II!
ASTM C172- Para (6.1) II! II! II!
II! Q5. The composite sample should not be remixed before beginning any tests.
II! II! II! II! II! II! II! II! II! II! II!
A. True II!
B. False - Correct Answers B. False
II! II! II! II! II! II! II! II! II! II!
ASTM C172-Para (4.1.1) -The sample shall be combined and remixed with a shovel the minimum amount
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
necessary to ensure uniformity and compliance with the maximum time limits
II! II! II! II! II! II! II! II! II! II! II!
II! Q6. Sampling should normally be performed, as the concrete is discharged from the mixer.
II! II! II! II! II! II! II! II! II! II! II! II! II!
A. True II!
B. False - Correct Answers B. False
II! II! II! II! II! II! II! II! II! II!
II! ASTM C172-Para (5). NOTE 2—Sampling should normally be performed as the concrete is delivered from
II! II! II! II! II! II! II! II! II! II! II! II! II! II!
II! the mixer.II! II!
To the conveying vehicle used to transport the
II! II! II! II! II! II! II!
,concrete to the forms; however, specifications may require other points of sampling, such as the
II! II! II! II! II! II! II! II! II! II! II! II! II! II!
discharge of a concrete pump.
II! II! II! II! II!
II! Q7. ASTM Method C172 includes sampling from stationary mixers, paving mixers, truck mixers, agitators,
II! II! II! II! II! II! II! II! II! II! II! II! II!
II! and non-agitating equipment.
II! II!
A. True II!
B. False - Correct Answers A. True
II! II! II! II! II! II! II! II! II! II! II!
ASTM C172- Para (1.1) II! II! II!
II! Q8. After sampling is completed, start the tests for slump and air content within:
II! II! II! II! II! II! II! II! II! II! II! II! II!
A. 2 ½ minutes
II! II! II!
B. 10 minutes
II! II!
C. 15 minutes
II! II!
D. None of the above - Correct Answers D. None of the above
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
ASTM C172- Para (4.1.2) Start tests for slump, temperature, and air content within 5 min after obtaining
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
the final portion of the composite sample.
II! II! II! II! II! II! II!
II! Q9. In any case, do not obtain samples until:
II! II! II! II! II! II! II! II!
A. All the water and admixtures have been added to the concrete
II! II! II! II! II! II! II! II! II! II! II!
B. 200 revolutions of the drum have been obtained
II! II! II! II! II! II! II! II!
C. ½ of the water has been added
II! II! II! II! II! II! II!
D. None of the above - Correct Answers A. All the water and admixtures have been added to the
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
concrete.
II!
, ASTM C172- Para (5.2.3). In any case do not obtain samples until after all of the water has been added to
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
the mixer.
II! II!
II! Q10. No samples shall be taken before_________ or after_________ of the batch has been discharged.
II! II! II! II! II! II! II! II! II! II! II! II! II! II!
A. 10% or after 90%
II! II! II! II!
B. 20% or after 90%
II! II! II! II!
C. 20% or after 80%
II! II! II! II!
D. None of the above - Correct Answers A. 10% or after 90%
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
ASTM C172- Para (5.2.1). II! II! II!
NOTE 3—No samples should be taken before 10 % or after 90 % of the batch has been discharged.
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
Due to the difficulty of determining the actual quantity of concrete discharged, the intent is to provide
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
samples that are representative of widely separated portions, but not the beginning and the end of the
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
load.
II!
II! Q11. When strength tests are to be made, the minimum size of the composite sample shall be:
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
A. ¼ cubic foot
II! II! II!
B. 1 cubic foot
II! II! II!
C. Any convenient size
II! II! II!
D. 1 Wheelbarrow - Correct Answers B. 1 cubic foot
II! II! II! II! II! II! II! II! II! II! II! II! II!
ASTM C172- Para (5.1). II! II! II!
Make the samples to be used for strength tests a minimum of 28 L (1 ft3).
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
II! Q12. Sample the concrete from the chute of a truck mixer by:
II! II! II! II! II! II! II! II! II! II! II!
Grade 1 Requires a working knowledge of
seven basic field tests on freshly mixed
concrete. ASTM test methods and practices
updated
Q1. Start molding specimens for strength tests within 30 minutes after fabricating the composite sample.
II! II! II! II! II! II! II! II! II! II! II! II! II! II!
A. True II!
B. False - Correct Answers B. False
II! II! II! II! II! II! II! II! II! II! II!
II! ASTM C172 -Para (4.1.2) - Start molding.
II! II! II! II! II! II!
specimens for strength tests within 15 min after fabricating the II! II! II! II! II! II! II! II! II!
composite sample. II!
II! Q2. The maximum allowable time between obtaining the first and last portions of the composite sample
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
II! may not exceed 5 minutes.
II! II! II! II!
A. True II!
B. False - Correct Answers B. False
II! II! II! II! II! II! II! II! II! II! II!
ASTM C172 - Para (4.1)- The elapsed time shall not exceed 15 min. between obtaining the first and final
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
portions of the composite sample.
II! II! II! II! II!
II! Q3. The composite concrete sample must be protected from sun, wind, contamination and rapid
II! II! II! II! II! II! II! II! II! II! II! II! II!
II! evaporation.
,A. True II!
B. False - Correct Answers A. True
II! II! II! II! II! II! II! II! II! II! II!
ASTM C172 - Para (4.1.2) II! II! II! II!
II! Q4. If the concrete contains aggregates larger than those that are appropriate for a size of mold or
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
II! equipment used, the sample should be wet sieved before making the test.
II! II! II! II! II! II! II! II! II! II! II!
A. True II!
B. False - Correct Answers A. True
II! II! II! II! II! II! II! II! II! II!
ASTM C172- Para (6.1) II! II! II!
II! Q5. The composite sample should not be remixed before beginning any tests.
II! II! II! II! II! II! II! II! II! II! II!
A. True II!
B. False - Correct Answers B. False
II! II! II! II! II! II! II! II! II! II!
ASTM C172-Para (4.1.1) -The sample shall be combined and remixed with a shovel the minimum amount
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
necessary to ensure uniformity and compliance with the maximum time limits
II! II! II! II! II! II! II! II! II! II! II!
II! Q6. Sampling should normally be performed, as the concrete is discharged from the mixer.
II! II! II! II! II! II! II! II! II! II! II! II! II!
A. True II!
B. False - Correct Answers B. False
II! II! II! II! II! II! II! II! II! II!
II! ASTM C172-Para (5). NOTE 2—Sampling should normally be performed as the concrete is delivered from
II! II! II! II! II! II! II! II! II! II! II! II! II! II!
II! the mixer.II! II!
To the conveying vehicle used to transport the
II! II! II! II! II! II! II!
,concrete to the forms; however, specifications may require other points of sampling, such as the
II! II! II! II! II! II! II! II! II! II! II! II! II! II!
discharge of a concrete pump.
II! II! II! II! II!
II! Q7. ASTM Method C172 includes sampling from stationary mixers, paving mixers, truck mixers, agitators,
II! II! II! II! II! II! II! II! II! II! II! II! II!
II! and non-agitating equipment.
II! II!
A. True II!
B. False - Correct Answers A. True
II! II! II! II! II! II! II! II! II! II! II!
ASTM C172- Para (1.1) II! II! II!
II! Q8. After sampling is completed, start the tests for slump and air content within:
II! II! II! II! II! II! II! II! II! II! II! II! II!
A. 2 ½ minutes
II! II! II!
B. 10 minutes
II! II!
C. 15 minutes
II! II!
D. None of the above - Correct Answers D. None of the above
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
ASTM C172- Para (4.1.2) Start tests for slump, temperature, and air content within 5 min after obtaining
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
the final portion of the composite sample.
II! II! II! II! II! II! II!
II! Q9. In any case, do not obtain samples until:
II! II! II! II! II! II! II! II!
A. All the water and admixtures have been added to the concrete
II! II! II! II! II! II! II! II! II! II! II!
B. 200 revolutions of the drum have been obtained
II! II! II! II! II! II! II! II!
C. ½ of the water has been added
II! II! II! II! II! II! II!
D. None of the above - Correct Answers A. All the water and admixtures have been added to the
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
concrete.
II!
, ASTM C172- Para (5.2.3). In any case do not obtain samples until after all of the water has been added to
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
the mixer.
II! II!
II! Q10. No samples shall be taken before_________ or after_________ of the batch has been discharged.
II! II! II! II! II! II! II! II! II! II! II! II! II! II!
A. 10% or after 90%
II! II! II! II!
B. 20% or after 90%
II! II! II! II!
C. 20% or after 80%
II! II! II! II!
D. None of the above - Correct Answers A. 10% or after 90%
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
ASTM C172- Para (5.2.1). II! II! II!
NOTE 3—No samples should be taken before 10 % or after 90 % of the batch has been discharged.
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
Due to the difficulty of determining the actual quantity of concrete discharged, the intent is to provide
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
samples that are representative of widely separated portions, but not the beginning and the end of the
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
load.
II!
II! Q11. When strength tests are to be made, the minimum size of the composite sample shall be:
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
A. ¼ cubic foot
II! II! II!
B. 1 cubic foot
II! II! II!
C. Any convenient size
II! II! II!
D. 1 Wheelbarrow - Correct Answers B. 1 cubic foot
II! II! II! II! II! II! II! II! II! II! II! II! II!
ASTM C172- Para (5.1). II! II! II!
Make the samples to be used for strength tests a minimum of 28 L (1 ft3).
II! II! II! II! II! II! II! II! II! II! II! II! II! II! II!
II! Q12. Sample the concrete from the chute of a truck mixer by:
II! II! II! II! II! II! II! II! II! II! II!
