ACI Certification Field Testing Technician 2 — Questions and Answers
Question 1: Per ASTM C143, the height of the standard slump cone is:
- 8 inches
- 10 inches
- 12 inches (Correct answer)
- 14 inches
Correct answer: 12 inches
The standard slump cone is 12 inches (305 mm) tall per ASTM C143.
Question 2: When performing the slump test per ASTM C143, the concrete is placed in the mold in:
- 1 layer
- 2 layers
- 3 layers (Correct answer)
- 4 layers
Correct answer: 3 layers
ASTM C143 requires filling the cone in 3 equal layers, each rodded 25 times with a tamping rod.
Question 3: The entire slump test procedure from start of filling the mold to removal of the cone must be completed within:
- 1 minute
- 2 minutes and 30 seconds (Correct answer)
- 5 minutes
- 10 minutes
Correct answer: 2 minutes and 30 seconds
ASTM C143 requires the complete procedure from start of filling to cone removal to be done within 2 minutes and 30 seconds.
Question 4: The tamping rod specified in ASTM C143 for the slump test is:
- 3/8 inch diameter, 18 inches long, bullet-pointed
- 5/8 inch diameter, 24 inches long, hemispherical end (Correct answer)
- 1/2 inch diameter, 12 inches long, flat end
- 5/8 inch diameter, 18 inches long, flat end
Correct answer: 5/8 inch diameter, 24 inches long, hemispherical end
ASTM C143 specifies a 5/8-inch (16 mm) diameter, 24-inch (600 mm) long rod with a rounded hemispherical tip.
Question 5: Per ASTM C143, the slump measurement is recorded to the nearest:
- 1/8 inch
- 1/4 inch (Correct answer)
- 1/2 inch
- 1 inch
Correct answer: 1/4 inch
ASTM C143 requires reporting the slump to the nearest 1/4 inch (5 mm).
Question 6: If concrete produces a shear slump (falls to one side) on the first test attempt per ASTM C143, the technician should:
- Record it as a failed slump test
- Repeat the test using a new sample from the same batch (Correct answer)
- Average the partial slump result with zero
- Add water to increase workability and retest
Correct answer: Repeat the test using a new sample from the same batch
A shear slump on the first attempt requires repeating the test; if it shears again on the second try, the concrete lacks the plasticity needed for a valid slump result.
Question 7: Per ASTM C1064, a temperature-measuring device must remain immersed in fresh concrete for a minimum of:
- 30 seconds
- 1 minute
- 2 minutes (Correct answer)
- 5 minutes
Correct answer: 2 minutes
ASTM C1064 requires the thermometer to remain inserted in the concrete for at least 2 minutes before reading the temperature.
ACI Certification Field Testing Technician 2
Per ASTM C143, the height of the standard slump cone is: