ACI Concrete Field-Testing Technician Grade I Certification Exam CP-1 (12) (Latest Update 2025 / 2026) Questions & Answers | Grade A | 100% Correct
ASTM C138
Standard Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
Question:
The diameter of the tamping rod used in this test method is _____ .
Answer:
⅝ in. [16 mm]
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Question:
What is the required shape of the tamping end of the rod?
Answer:
Rounded to a hemispherical tip
Question:
What is the required minimum frequency of the vibrator used in this test method?
Answer:
7000 vibrations per minute
Question:
The outside diameter or side dimension of the vibrating element must be at least _____ but not greater than _____ .
Answer:
0.75 in. [19 mm], 1.50 in. [38 mm]
Question:
A plastic container can be used for the measure in this method. True or False?
Answer:
False, measure must be steel or other suitable metal 2 / 4
Question:
What is the minimum thickness of a metal strike-off plate?
Answer:
¼ in. [6 mm]
Question:
What is the minimum thickness for a glass or acrylic strike-off plate?
Answer:
½ in. [12 mm]
Question:
What is the specified weight of the mallet used on measures that are 0.5 ft3 [14 L] or smaller?
Answer:
1.25 ± 0.50 lb. [600 ± 200 g]
Question:
Measures other than air meter bowls used for this test must conform to ASTM
_____.
Answer:
C29 3 / 4
Question:
Air meter bowls used for this test must conform to ASTM _____ and be calibrated for volume according to ASTM _____.
Answer:
C231, C29
Question:
The concrete sample must be obtained in accordance with what ASTM method?
Answer:
C172
Question:
What method of consolidation must be used when the slump is greater than 3 in. [75 mm]?
Answer:
Rodding
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