Certification Exam for the 2026/2027 cycle,
featuring complete exam-style questions with
accurate, up-to-date answers.
Q1. Start molding specimens for strength tests within 30
minutes after fabricating the composite sample.
A. True
B. False
B. False
ASTM C172 -Para (4.1.2) - Start molding.
specimens for strength tests within 15 min after fabricating the
composite sample.
Q2. The maximum allowable time between obtaining the first
and last portions of the composite sample may not exceed 5
minutes.
A. True
B. False
B. False
ASTM C172 - Para (4.1)- The elapsed time shall not exceed 15
min. between obtaining the first and final portions of the
composite sample.
Q3. The composite concrete sample must be protected from
sun, wind, contamination and rapid evaporation.
A. True
B. False
,A. True
ASTM C172 - Para (4.1.2)
Q4. If the concrete contains aggregates larger than those that
are appropriate for a size of mold or equipment used, the
sample should be wet sieved before making the test.
A. True
B. False
A. True
ASTM C172- Para (6.1)
Q5. The composite sample should not be remixed before
beginning any tests.
A. True
B. False
B. False
ASTM C172-Para (4.1.1) -The sample shall be combined and
remixed with a shovel the minimum amount necessary to ensure
uniformity and compliance with the maximum time limits
Q6. Sampling should normally be performed, as the concrete
is discharged from the mixer.
A. True
B. False
B. False
ASTM C172-Para (5). NOTE 2—Sampling should normally be
performed as the concrete is delivered from the mixer.
To the conveying vehicle used to transport the
concrete to the forms; however, specifications may require other
points of sampling, such as the discharge of a concrete pump.
,Q7. ASTM Method C172 includes sampling from stationary
mixers, paving mixers, truck mixers, agitators, and non-
agitating equipment.
A. True
B. False
A. True
ASTM C172- Para (1.1)
Q8. After sampling is completed, start the tests for slump
and air content within:
A. 2 ½ minutes
B. 10 minutes
C. 15 minutes
D. None of the above
D. None of the above
ASTM C172- Para (4.1.2) Start tests for slump, temperature, and
air content within 5 min after obtaining the final portion of the
composite sample.
Q9. In any case, do not obtain samples until:
A. All the water and admixtures have been added to the
concrete
B. 200 revolutions of the drum have been obtained
C. ½ of the water has been added
D. None of the above
A. All the water and admixtures have been added to the concrete.
ASTM C172- Para (5.2.3). In any case do not obtain samples until
after all of the water has been added to the mixer.
Q10. No samples shall be taken before_________ or
after_________ of the batch has been discharged.
, A. 10% or after 90%
B. 20% or after 90%
C. 20% or after 80%
D. None of the above
A. 10% or after 90%
ASTM C172- Para (5.2.1).
NOTE 3—No samples should be taken before 10 % or after 90 %
of the batch has been discharged.
Due to the difficulty of determining the actual quantity of concrete
discharged, the intent is to provide samples that are
representative of widely separated portions, but not the beginning
and the end of the load.
Q11. When strength tests are to be made, the minimum size
of the composite sample shall be:
A. ¼ cubic foot
B. 1 cubic foot
C. Any convenient size
D. 1 Wheelbarrow
B. 1 cubic foot
ASTM C172- Para (5.1).
Make the samples to be used for strength tests a minimum of 28
L (1 ft3).
Q12. Sample the concrete from the chute of a truck mixer by:
A. Raising chute to stop the flow and scoop concrete from
there into the slump cone and cylinder molds
B. Passing a receptacle completely through the discharge
steam or by completely diverting the discharge into the
sample container