ACI Concrete Field-Testing

ACI Concrete Field-Testing Technician Grade I Certification Exam (Latest Update 2025 / 2026) Questions & Answers | Grade A | 100% Correct

Question:

Vibration of the concrete sample is not allowed when the slump of the concrete exceeds ___.

Answer:

• in. (75 mm)

Question:

In rodding the sample, how deep should the rod penetrate each layer?

Answer:

Rod bottom layer to full depth; rod second and final layer penetrating the previous layer about 1 in. (25 mm)

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Question:

After rodding each layer, what should be done to the measure before adding another layer of concrete?

Answer:

Tap the sides of the measure smartly 10-15 times with the mallet

Question:

When consolidating the concrete by vibration, how many times should the vibrator be inserted into each layer?

Answer:

3

Question:

What tools may be used to strike off the top surface of the concrete following consolidation of the final layer?

Answer:

A strike-off bar; a metal, glass, or acrylic plate

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Question:

What must be done if there is a slight deficiency in the quantity of concrete in the measure following consolidation of the final layer?

Answer:

Add a quantity of representative concrete before strike off

Question:

What must be done if there is an excessive amount of concrete in the measure following consolidation of the final layer?

Answer:

Remove a representative portion of the excess concrete with a trowel or scoop before strike off

Question:

The volumetric method of determining air content of concrete can be used on concrete containing what types of aggregate?

Answer:

All types of aggregate

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Question:

What are the requirements for the tamping rod used in this test method?

Answer:

Round, straight 5/8 in. (16 mm) +- 1/16 in. (2 mm) diameter rod at least 4 in.(102 mm) greater in length than the depth of the bowl being used, with the tamping end rounded to a hemispherical tip of the same diameter, made of steel, high-density polyethylene, or other plastic of equal or greater abrasion resistance.

Question:

What are the requirements for the strike-off bar used in this test method?

Answer:

Flat, straight steel bar at least 1/8 by 3/4 by 12 in. (3 by 20 by 300 mm) or a flat, straight high-density polyethylene bar, or other plastic of equal or greater abrasion resistance, at least 1/4 by 3/4 by 12 in. (6 by 20 by 300 mm)

Question:

What is the approximate volume of the measuring cup used to add water to the air meter, in relation to the volume of the air meter bowl?

Answer:

1.00% +- 0.04%

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