ACI Concrete Field Testing Technician
Grade- I (Grade One) Certification Practice
Exam | Complete Questions, Answers &
Detailed Rationales | 2026/2027 Edition
Question 1
For concrete with aggregates less than 3 inches, the thermometer must remain in the
fresh concrete sample a minimum of 5 minutes or until the temperature reading
stabilizes. (T or F)
Answer: False. ✔✔
Rationale: The temperature measuring device must remain in the concrete for at least
2 minutes but not more than 5 minutes, or until the temperature reading stabilizes.
Question 2
The temperature measuring device must be accurate to within 0.1°F. (T or F)
Answer: False. ✔✔
Rationale: The temperature measuring device must be accurate to within ±1°F
(±0.5°C), not 0.1°F.
Question 3
The temperature measuring device shall have a capacity of measuring temperature of
freshly mixed concrete throughout a range of ___ °F to ___ °F (___ °C to ___ °C).
Answer: 30°F to 120°F (0°C to 50°C). ✔✔
Rationale: The temperature measuring device must be capable of measuring
temperatures across the range typically encountered in concrete production and
placement.
Question 4
A composite sample is not needed if only the temperature test is being run. (T or F)
Answer: True. ✔✔
Rationale: A composite sample is not required solely for temperature determination; a
single grab sample is sufficient.
pg. 1
,Question 5
The temperature of fresh concrete in a placement must be measured by inserting a
thermometer into the top six inches of concrete. (T or F)
Answer: False. ✔✔
Rationale: The temperature sensor must be submerged a minimum of 3 inches (75
mm) into the freshly mixed concrete, not necessarily the top six inches.
Question 6
The temperature of the concrete is recorded to the nearest ___ °F (___ °C).
Answer: 1°F (0.5°C). ✔✔
Rationale: Temperature is reported to the nearest 1°F (0.5°C) for practical accuracy.
Question 7
ASTM C1064 states the container used to measure temperature of concrete must be
large enough to provide at least 5 inches of concrete around the sensor. (T or F)
Answer: False. ✔✔
Rationale: The sensor must be submerged a minimum of 3 inches (75 mm) into the
concrete, not 5 inches.
Question 8
Calibrate the temperature measuring device at least ___, or whenever there is a
question of accuracy.
Answer: Annually. ✔✔
Rationale: The temperature measuring device shall be calibrated annually, or
whenever there is a question of accuracy.
Question 9
After the thermometer is placed in the concrete:
Answer: Gently press concrete around the thermometer. ✔✔
Rationale: Pressing the concrete around the device ensures good thermal contact and
prevents air gaps that could affect the reading.
pg. 2
, Question 10
According to ASTM C1064, what is one reason to take the temperature of concrete?
Answer: Verify conformance. ✔✔
Rationale: Temperature measurement ensures the concrete meets specification
requirements for placement temperature.
Question 11
It is allowable to remove the temperature measuring devices from the freshly mixed
concrete to read the temperature if you cannot see the reading. (T or F)
Answer: False. ✔✔
Rationale: The temperature should be read while the device is still in the concrete to
maintain accurate measurement.
Question 12
The maximum allowable time between obtaining the first and last portions of the
composite sample may not exceed 5 minutes. (T or F)
Answer: False. ✔✔
Rationale: The maximum allowable time between obtaining the first and final portions
of a composite sample is 15 minutes, not 5 minutes.
Question 13
Start molding specimens for strength tests within 30 minutes after fabricating the
composite sample. (T or F)
Answer: False. ✔✔
Rationale: The molding of strength test specimens shall begin within 15 minutes after
fabricating the composite sample.
Question 14
The composite concrete sample must be protected from sun, wind, contamination and
rapid evaporation. (T or F)
Answer: True. ✔✔
Rationale: The concrete sample must be protected from contamination and rapid
evaporation to maintain its properties.
pg. 3
Grade- I (Grade One) Certification Practice
Exam | Complete Questions, Answers &
Detailed Rationales | 2026/2027 Edition
Question 1
For concrete with aggregates less than 3 inches, the thermometer must remain in the
fresh concrete sample a minimum of 5 minutes or until the temperature reading
stabilizes. (T or F)
Answer: False. ✔✔
Rationale: The temperature measuring device must remain in the concrete for at least
2 minutes but not more than 5 minutes, or until the temperature reading stabilizes.
Question 2
The temperature measuring device must be accurate to within 0.1°F. (T or F)
Answer: False. ✔✔
Rationale: The temperature measuring device must be accurate to within ±1°F
(±0.5°C), not 0.1°F.
Question 3
The temperature measuring device shall have a capacity of measuring temperature of
freshly mixed concrete throughout a range of ___ °F to ___ °F (___ °C to ___ °C).
Answer: 30°F to 120°F (0°C to 50°C). ✔✔
Rationale: The temperature measuring device must be capable of measuring
temperatures across the range typically encountered in concrete production and
placement.
Question 4
A composite sample is not needed if only the temperature test is being run. (T or F)
Answer: True. ✔✔
Rationale: A composite sample is not required solely for temperature determination; a
single grab sample is sufficient.
pg. 1
,Question 5
The temperature of fresh concrete in a placement must be measured by inserting a
thermometer into the top six inches of concrete. (T or F)
Answer: False. ✔✔
Rationale: The temperature sensor must be submerged a minimum of 3 inches (75
mm) into the freshly mixed concrete, not necessarily the top six inches.
Question 6
The temperature of the concrete is recorded to the nearest ___ °F (___ °C).
Answer: 1°F (0.5°C). ✔✔
Rationale: Temperature is reported to the nearest 1°F (0.5°C) for practical accuracy.
Question 7
ASTM C1064 states the container used to measure temperature of concrete must be
large enough to provide at least 5 inches of concrete around the sensor. (T or F)
Answer: False. ✔✔
Rationale: The sensor must be submerged a minimum of 3 inches (75 mm) into the
concrete, not 5 inches.
Question 8
Calibrate the temperature measuring device at least ___, or whenever there is a
question of accuracy.
Answer: Annually. ✔✔
Rationale: The temperature measuring device shall be calibrated annually, or
whenever there is a question of accuracy.
Question 9
After the thermometer is placed in the concrete:
Answer: Gently press concrete around the thermometer. ✔✔
Rationale: Pressing the concrete around the device ensures good thermal contact and
prevents air gaps that could affect the reading.
pg. 2
, Question 10
According to ASTM C1064, what is one reason to take the temperature of concrete?
Answer: Verify conformance. ✔✔
Rationale: Temperature measurement ensures the concrete meets specification
requirements for placement temperature.
Question 11
It is allowable to remove the temperature measuring devices from the freshly mixed
concrete to read the temperature if you cannot see the reading. (T or F)
Answer: False. ✔✔
Rationale: The temperature should be read while the device is still in the concrete to
maintain accurate measurement.
Question 12
The maximum allowable time between obtaining the first and last portions of the
composite sample may not exceed 5 minutes. (T or F)
Answer: False. ✔✔
Rationale: The maximum allowable time between obtaining the first and final portions
of a composite sample is 15 minutes, not 5 minutes.
Question 13
Start molding specimens for strength tests within 30 minutes after fabricating the
composite sample. (T or F)
Answer: False. ✔✔
Rationale: The molding of strength test specimens shall begin within 15 minutes after
fabricating the composite sample.
Question 14
The composite concrete sample must be protected from sun, wind, contamination and
rapid evaporation. (T or F)
Answer: True. ✔✔
Rationale: The concrete sample must be protected from contamination and rapid
evaporation to maintain its properties.
pg. 3
