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ertification Exam (4).
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ACI Certification Exam (4).
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ACI Certification Exam2. T/F: When the concrete contains large aggregate, the testing technician should wet-sieve the
sample before making unit weight tests for use in yield computations. - ANS-False
4. T/F: Samples smaller than 28L (1 cu.ft.) are allowed on routine air content, temperature, and
slump tests. - ANS-True
7. How do you regulate the rate of discharge of the batch from the revolving truck drum mixer or
agitator? - ANS-By the rate of revolution of the drum
10. While the technician is checking the slump of the concrete, there is a decided falling away or
shearing off of the concrete from one side of the sample. What should the technician do? -
ANS-Disregard the test and retest on another portion of the sample
11. The mold is filled in three equal layers by volume, which makes the first third at _______,
and the second third at ________. - ANS-2 5/8, 6 1/8
15. What is the difference allowed by ACI when certifying an individual test using a plastic slump
cone vs. a metal slump cone? - ANS-0.5 inches
16. T/F: The sides of the slump mold should be lightly tapped to consolidate the concrete in the
mold. - ANS-False
18. T/F: ASTM C 1064 defines the maximum recommended temperature for concrete. -
ANS-False
19. The temperature test method must be complete with in _________ after obtaining the
sample. - ANS-5 minutes
20. Each temperature-measuring device should be calibrated ________, or whenever there is a
question of _________. - ANS-annually, accuracy
23. T/F: After strike off of the measure used to determine density, a small quantity of concrete
may be added to correct a deficiency? - ANS-False
26. What is the required shape at the end of the tamping rod? - ANS-rounded to a
hemispherical tip
28. How do you find the density of a concrete batch? - ANS-(mass of measure with concrete -
mass of measure) / volume of measure
, 29. How do you find the yield of a concrete batch? - ANS-(mass of all materials batched /
(density of concrete * 27))
33. T/F: Test method ASTM C231 is intended for use with all concretes and aggregates for
which an aggregate correction factor can be determined - ANS-False
34. T/F: The petcocks are closed before pumping any air into the chamber on the type B meter.
- ANS-False
36. The sample is obtained in accordance to ASTM C ___________. - ANS-172
37. If the aggregate correction factor for a given source of fine and coarse aggregate is found to
be 0.2% in a pressure air meter, and an air content value of 5.0% is read on the gauge of the
same air meter containing concrete with the same aggregate, what is the correct air content? -
ANS-4.8%
39. If the sample is vibrated the duration of vibration should last ___________. - ANS-Until the
surface concrete is smooth
40. The maximum size aggregate for this test is _________. - ANS-2''
41. If the aggregate is too large, it must be ________________. - ANS-Wet sieved over the 1
1/2" sieve
42. The minimum size of the measure is ________________________. - ANS-Dependant upon
the nominal maximum coarse aggregate size
43. At the end of the pressure method procedure, how is the pressure released from the Type B
air meter? - ANS-Opening both petcocks
46. T/F: ASTM 173 is appropriate for testing concretes containing lightweight aggregates. -
ANS-True
47. T/F: ASTM 173 specifies that at the very end of the test the tester must make sure that there
are portions undisturbed in the bottom of the bowl, if so the test is valid. - ANS-False
48. The maximum size aggregate for this test is _________. - ANS-1 1/2''
49. If the second reading after rolling and rocking differs by more than 0.25% from the first,
_______________. - ANS-Rock and roll the meter again
50. You added 2 pints of alcohol to the roll-a-meter before you started. Your final reading after
competing the test is 5.5% air. What is the recorded air reading? - ANS-5.5% air
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