ACI Concrete Field-Testing

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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