ACI Exam Prep Free practice test →

Free ACI Practice Questions

10 free, exam-style ACI Concrete Field Testing Technician Grade I (ACI) practice questions with answers and explanations. No signup required. Work through them below, then take the full free ACI practice test to study every exam domain.

Question 1

Concrete made with lightweight aggregate requires an air content test. Which test method MUST be used?

  1. ASTM C231 - the pressure method using a Type B meter
  2. ASTM C138 - the gravimetric method based on density
  3. ASTM C173 - the volumetric method
  4. Any standardized air content method may be used regardless of aggregate type
Show answer & explanation

Correct answer: C - ASTM C173 - the volumetric method

Question 2

During the slump test per ASTM C143, should the sides of the slump cone be tapped with a mallet after each layer?

  1. Yes - tap the sides 10 to 15 times with a rubber mallet after rodding each layer
  2. No - do NOT tap the sides of the slump cone at any point during the test
  3. Yes - lightly tap the sides 5 times after completing all three layers
  4. Yes - tap the sides only when the expected slump is less than 3 inches
Show answer & explanation

Correct answer: B - No - do NOT tap the sides of the slump cone at any point during the test

Question 3

A technician obtains the final composite portion at 2:30 PM. Temperature is measured at 2:31 PM. Slump test begins at 2:33 PM. Air content test begins at 2:34 PM. Cylinder molding begins at 2:48 PM. Which ASTM C172 time limit was violated?

  1. The 5-minute limit for starting the slump test was exceeded by 3 minutes
  2. The 5-minute limit for starting the air content test was exceeded by 4 minutes
  3. No time limits were violated - all testing activities are within C172 requirements
  4. The 15-minute limit for starting to mold strength specimens was exceeded
Show answer & explanation

Correct answer: D - The 15-minute limit for starting to mold strength specimens was exceeded

Question 4

Concrete has a measured slump of 3/4 inch. A technician decides to rod the density measure per ASTM C138. This decision is:

  1. Not acceptable - slump below 1 inch must be vibrated
  2. Acceptable - rodding is the default consolidation method for all slump ranges
  3. Acceptable - but the technician must increase to 50 rod strokes per layer
  4. Not acceptable - concrete with slump below 1 inch does not require consolidation
Show answer & explanation

Correct answer: A - Not acceptable - slump below 1 inch must be vibrated

Question 5

The theoretical (air-free) density of a concrete mix is 150.0 lb/ft³. The measured density per ASTM C138 is 144.0 lb/ft³. What is the gravimetric air content?

  1. 2.0%
  2. 4.0%
  3. 6.0%
  4. 8.0%
Show answer & explanation

Correct answer: B - 4.0%

Question 6

Per ASTM C31, the correct rodding parameters (layers / strokes per layer) for each cylinder size are:

  1. 4×8: 2 layers, 25 strokes | 6×12: 3 layers, 25 strokes | 9×18: 4 layers, 50 strokes
  2. 4×8: 3 layers, 25 strokes | 6×12: 3 layers, 25 strokes | 9×18: 3 layers, 50 strokes
  3. 4×8: 2 layers, 25 strokes | 6×12: 2 layers, 25 strokes | 9×18: 2 layers, 50 strokes
  4. 4×8: 2 layers, 50 strokes | 6×12: 3 layers, 50 strokes | 9×18: 4 layers, 50 strokes
Show answer & explanation

Correct answer: A - 4×8: 2 layers, 25 strokes | 6×12: 3 layers, 25 strokes | 9×18: 4 layers, 50 strokes

Question 7

A technician uses a 5/8-inch (16 mm) diameter tamping rod to consolidate a 4×8 inch test cylinder. Per ASTM C31, this is:

  1. Correct - the 5/8-inch rod is the standard tamping rod for all cylinder mold sizes
  2. Correct - rod diameter has no significant effect on consolidation of small specimens
  3. Incorrect - a 4-inch diameter mold requires a 3/4-inch (19 mm) diameter tamping rod
  4. Incorrect - a 4-inch diameter mold requires the 3/8-inch (10 mm) rod
Show answer & explanation

Correct answer: D - Incorrect - a 4-inch diameter mold requires the 3/8-inch (10 mm) rod

Question 8

How does the initial curing temperature requirement for high-strength concrete (≥ 6,000 psi) differ from standard concrete (< 6,000 psi) per ASTM C31?

  1. High-strength requires a higher range of 80-100°F to accelerate early strength gain
  2. High-strength requires a narrower range: 68-78°F versus 60-80°F for standard
  3. There is no difference - both use the same 60-80°F initial curing temperature range
  4. High-strength requires a wider range of 50-90°F to accommodate specialty admixtures
Show answer & explanation

Correct answer: B - High-strength requires a narrower range: 68-78°F versus 60-80°F for standard

Question 9

After completing the ASTM C173 volumetric air content test, the technician removes the top section and finds undisturbed portions of concrete remaining in the bowl. The test result is:

  1. Valid - undisturbed concrete at the bottom of the bowl does not affect accuracy
  2. Valid - but the technician should adjust the reading upward by 0.5% to compensate
  3. Invalid - undisturbed concrete means not all air was displaced; must retest
  4. Valid - record the reading as-is with a notation about the remaining concrete
Show answer & explanation

Correct answer: C - Invalid - undisturbed concrete means not all air was displaced; must retest

Question 10

To pass the ACI Concrete Field Testing Technician - Grade I written examination, a candidate must achieve:

  1. At least 60% on each ASTM section AND at least 70% overall
  2. A minimum overall score of 70% with no individual section requirement
  3. A minimum overall score of 80% across all 55 questions combined
  4. At least 50% on each ASTM section AND at least 60% overall
Show answer & explanation

Correct answer: A - At least 60% on each ASTM section AND at least 70% overall

Ready for the real thing?

Practice hundreds more ACI questions with instant scoring, weak-area drills, and full exam simulations.

Start the free practice test See pricing