2. 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.Answer - False
4. T/F: Samples smaller than 28L (1 .) are allowed on routine air content, temperature, and slump tests.Answer - T...
ACI Certification Exam 2024 with 100%
correct answers
2. 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.Answer ✔✔ - False
4. T/F: Samples smaller than 28L (1 cu.ft.) are allowed on routine air content, temperature, and slump
tests.Answer ✔✔ - True
7. How do you regulate the rate of discharge of the batch from the revolving truck drum mixer or
agitator?Answer ✔✔ - 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?Answer ✔✔ -
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 ________.Answer ✔✔ - 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?Answer ✔✔ - 0.5 inches
16. T/F: The sides of the slump mold should be lightly tapped to consolidate the concrete in the
mold.Answer ✔✔ - False
18. T/F: ASTM C 1064 defines the maximum recommended temperature for concrete.Answer ✔✔ -
False
19. The temperature test method must be complete with in _________ after obtaining the
sample.Answer ✔✔ - 5 minutes
, 20. Each temperature-measuring device should be calibrated ________, or whenever there is a question
of _________.Answer ✔✔ - 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?Answer ✔✔ - False
26. What is the required shape at the end of the tamping rod?Answer ✔✔ - rounded to a hemispherical
tip
28. How do you find the density of a concrete batch?Answer ✔✔ - (mass of measure with concrete -
mass of measure) / volume of measure
29. How do you find the yield of a concrete batch?Answer ✔✔ - (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 determinedAnswer ✔✔ - False
34. T/F: The petcocks are closed before pumping any air into the chamber on the type B meter.Answer
✔✔ - False
36. The sample is obtained in accordance to ASTM C ___________.Answer ✔✔ - 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?Answer ✔✔ - 4.8%
39. If the sample is vibrated the duration of vibration should last ___________.Answer ✔✔ - Until the
surface concrete is smooth
40. The maximum size aggregate for this test is _________.Answer ✔✔ - 2''
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