I: Complete Study Guide with Questions,
Answers and Rationales |Latest Update 2026
Question 1
The sensor of the temperature measuring device shall be submerged a minimum of
_____ in. [_____mm] into the freshly mixed concrete.
Answer: 3 in. [75 mm]. ✔✔
Rationale: The temperature sensor must be submerged at least 3 inches into the
concrete to ensure an accurate reading of the internal temperature, avoiding surface
temperature variations.
Question 2
The temperature measuring device shall have a capacity of measuring temperature of
freshly mixed concrete to +- _____ degrees F [+- _____ C] throughout a range of
_____.
Answer: 1 degree F [0.5 C], 30 degrees F to 120 F [0 C to 50 C]. ✔✔
Rationale: The device must be accurate to within 1°F over the range of temperatures
typically encountered in concrete production and placement.
Question 3
The temperature measuring device shall be calibrated _____, or whenever there is a
question of _____.
Answer: Annually, accuracy. ✔✔
Rationale: Regular annual calibration ensures the device maintains accuracy;
recalibration is also required whenever accuracy is in doubt.
Question 4
The temperature of concrete may be measured in a wheelbarrow. True or False?
Answer: True. ✔✔
pg. 1
,Rationale: Temperature measurement can be taken from concrete in a wheelbarrow,
provided the sample is representative and properly handled.
Question 5
The temperature of concrete may be measured in a wall form. True or False?
Answer: True. ✔✔
Rationale: Temperature can be measured directly in wall forms, though sampling from
the delivery equipment is preferred for accuracy.
Question 6
A composite sample of concrete is required even if the only purpose for obtaining the
sample is to determine temperature. True or False?
Answer: False. ✔✔
Rationale: A composite sample is not required solely for temperature determination; a
single grab sample is sufficient.
Question 7
What must be done to the sample container prior to sampling the concrete?
Answer: Dampen (with water). ✔✔
Rationale: Dampening the container prevents absorption of water from the concrete,
which could alter the water-cement ratio.
Question 8
What must be done to the concrete surrounding the temperature measuring device after
the device is submerged in the fresh concrete?
Answer: Gently press the concrete around the temperature measuring device at the
surface of the concrete. ✔✔
Rationale: Pressing the concrete around the device ensures good thermal contact and
prevents air gaps that could affect the reading.
Question 9
How long must the temperature measuring device remain in the freshly mixed concrete?
Answer: At least 2 minutes but not more than 5 minutes. ✔✔
pg. 2
, Rationale: The device must remain in the concrete long enough to stabilize but not so
long that the concrete cools or warms significantly.
Question 10
After the temperature of the concrete is read, what is required?
Answer: Reporting of temperature. ✔✔
Rationale: The temperature reading must be documented and reported as part of the
quality control record.
Question 11
The temperature of concrete is reported to the nearest _____ degrees F [_____ C].
Answer: 1 degree F [0.5 C]. ✔✔
Rationale: Reporting to the nearest 1°F provides sufficient precision for quality control
purposes.
Question 12
According to ASTM C1064, what is one reason to take the temperature of concrete?
Answer: Verify conformance to a specified requirement for temperature of concrete.
✔✔
Rationale: Temperature measurement ensures the concrete meets specification
requirements for placement temperature.
Question 13
A maximum temperature of freshly mixed concrete is specified in ASTM C1064. True or
False?
Answer: False. ✔✔
Rationale: ASTM C1064 does not specify maximum or minimum temperature limits; it
only provides the test method.
Question 14
The sample of concrete used for temperature determination must be rodded 25 times.
True or False?
Answer: False. ✔✔
pg. 3