ACI Concrete Field Testing Technician- Grade I Version 1 Actual Exam Newest With Complete
Questions And Correct Detailed Answers| Brand New Version!
Question 1
According to ASTM C1064, the sensor of the temperature measuring device must be submerged
a minimum of how many inches into the freshly mixed concrete?
A) 1 in. [25 mm]
B) 2 in. [50 mm]
C) 3 in. [75 mm]
D) 4 in. [100 mm]
E) 6 in. [150 mm]
Correct Answer: C) 3 in. [75 mm]
Rationale: ASTM C1064 requires a minimum of 3 inches [75 mm] of cover in all directions
around the sensor to ensure that the ambient air temperature does not influence the
reading of the concrete's internal temperature.
Question 2
What is the required accuracy for a temperature measuring device used to test freshly mixed
concrete?
A) ± 0.1° F [± 0.05° C]
B) ± 0.5° F [± 0.2° C]
C) ± 1.0° F [± 0.5° C]
D) ± 2.0° F [± 1.0° C]
E) ± 5.0° F [± 2.5° C]
Correct Answer: C) ± 1° F [± 0.5° C]
Rationale: The temperature measuring device must be capable of measuring the
temperature of the concrete with an accuracy of ± 1° F [± 0.5° C] throughout the range of
30° F to 120° F [0° C to 50° C].
Question 3
How often must the temperature measuring device be calibrated?
A) Monthly
B) Semi-annually
C) Annually
D) Every two years
E) Only when the battery is changed
Correct Answer: C) Annually
Rationale: ASTM C1064 specifies that the device must be calibrated annually or whenever
there is a question of accuracy to ensure the reliability of the field data.
Question 4
In which of the following containers or locations is it acceptable to measure the temperature of
freshly mixed concrete?
, 2
A) A wheelbarrow
B) A wall form
C) The discharge stream of a mixer
D) A concrete bucket
E) All of the above
Correct Answer: E) All of the above
Rationale: The temperature can be measured in any container or location as long as there is
at least 3 inches of concrete cover in all directions around the sensor and the sample is
representative.
Question 5
Is a composite sample of concrete required by ASTM C172 if the only purpose for obtaining the
sample is to determine the temperature?
A) Yes, a composite sample is always required for any test.
B) No, a composite sample is not required for temperature tests.
C) Yes, but only if the concrete contains air-entraining admixtures.
D) No, unless the concrete has a slump greater than 4 inches.
E) Yes, but only if the temperature is above 90° F.
Correct Answer: B) No, a composite sample is not required for temperature tests.
Rationale: ASTM C1064 allows for the temperature to be taken from a single portion of the
batch, provided the sensor has adequate cover; a full composite sample per ASTM C172 is
not mandatory for temperature alone.
Question 6
What preparation must be performed on the sample container prior to sampling the concrete for a
temperature test?
A) It must be bone dry.
B) It must be heated to the expected concrete temperature.
C) It must be dampened with water.
D) It must be coated with a release agent.
E) No preparation is required.
Correct Answer: C) Dampen (with water)
Rationale: The container should be dampened to prevent it from absorbing moisture from
the concrete sample, which could affect the properties and the temperature reading.
Question 7
After submerging the temperature measuring device in the concrete, what action should the
technician take regarding the concrete surrounding the device?
A) Rod the concrete 25 times.
B) Tap the sides of the container with a mallet.
C) Gently press the concrete around the device at the surface.
, 3
D) Vibrate the concrete for 5 seconds.
E) Stir the concrete with the sensor.
Correct Answer: C) Gently press the concrete around the temperature measuring device at
the surface of the concrete
Rationale: Gently pressing the concrete around the sensor ensures that the ambient air
temperature does not affect the sensor and that there is full contact between the concrete
and the measuring device.
Question 8
What is the required duration for the temperature measuring device to remain in the freshly
mixed concrete?
A) Exactly 1 minute
B) At least 2 minutes but not more than 5 minutes
C) At least 5 minutes
D) Until the reading stabilizes for 30 seconds
E) Exactly 10 minutes
Correct Answer: B) At least 2 minutes but not more than 5 minutes
Rationale: The device must remain in the concrete for a minimum of 2 minutes to allow for
stabilization, but not more than 5 minutes to avoid temperature changes caused by
hydration or ambient conditions.
Question 9
The temperature of the concrete must be reported to the nearest _________ degrees.
A) 0.1° F [0.1° C]
B) 0.5° F [0.2° C]
C) 1° F [0.5° C]
D) 2° F [1.0° C]
E) 5° F [2.5° C]
Correct Answer: C) 1 degree F [0.5 C]
Rationale: Standard reporting for ASTM C1064 requires the temperature to be rounded
and recorded to the nearest whole degree Fahrenheit or the nearest 0.5 degree Celsius.
Question 10
According to ASTM C1064, what is the primary reason for taking the temperature of freshly
mixed concrete?
A) To determine if the concrete will reach its 28-day strength.
B) To check for the presence of fly ash.
C) To verify conformance to a specified requirement for temperature.
D) To calculate the water-cement ratio.
E) To determine the setting time of the concrete.
Correct Answer: C) Verify conformance to a specified requirement for temperature of
, 4
concrete
Rationale: Project specifications often include a maximum or minimum allowable
temperature for concrete at the time of placement; C1064 provides the standardized
method to verify this compliance.
Question 11
Does ASTM C1064 specify a maximum allowable temperature for freshly mixed concrete?
A) Yes, 90° F [32° C].
B) Yes, 100° F [38° C].
C) No, a maximum temperature is not specified in the standard itself.
D) Yes, it depends on the cement type.
E) Yes, but only for mass concrete.
Correct Answer: C) False
Rationale: ASTM C1064 is a "how-to" method for measurement. The actual temperature
limits are found in the project specifications or other codes (like ACI 301), not within
C1064.
Question 12
Is it necessary to rod the concrete sample used for temperature determination 25 times?
A) Yes, to ensure consolidation.
B) No, rodding is not required for temperature determination.
C) Yes, but only if the slump is less than 1 inch.
D) No, it should be rodded 10 times.
E) Yes, only if using a metal container.
Correct Answer: B) False
Rationale: Rodding is not a part of the ASTM C1064 procedure. Consolidating the concrete
for a temperature test is not required and could potentially change the temperature
through friction or exposure.
Question 13
ASTM C172 (Sampling) is required when tests are being made to determine _________ with
specification requirements.
A) Profitability
B) Compliance
C) Aesthetic quality
D) Worker efficiency
E) Soil stability
Correct Answer: B) Compliance
Rationale: The standard practice for sampling is intended to ensure that the sample used for
testing is truly representative of the batch, allowing for an accurate determination of
compliance with project specifications.
Questions And Correct Detailed Answers| Brand New Version!
Question 1
According to ASTM C1064, the sensor of the temperature measuring device must be submerged
a minimum of how many inches into the freshly mixed concrete?
A) 1 in. [25 mm]
B) 2 in. [50 mm]
C) 3 in. [75 mm]
D) 4 in. [100 mm]
E) 6 in. [150 mm]
Correct Answer: C) 3 in. [75 mm]
Rationale: ASTM C1064 requires a minimum of 3 inches [75 mm] of cover in all directions
around the sensor to ensure that the ambient air temperature does not influence the
reading of the concrete's internal temperature.
Question 2
What is the required accuracy for a temperature measuring device used to test freshly mixed
concrete?
A) ± 0.1° F [± 0.05° C]
B) ± 0.5° F [± 0.2° C]
C) ± 1.0° F [± 0.5° C]
D) ± 2.0° F [± 1.0° C]
E) ± 5.0° F [± 2.5° C]
Correct Answer: C) ± 1° F [± 0.5° C]
Rationale: The temperature measuring device must be capable of measuring the
temperature of the concrete with an accuracy of ± 1° F [± 0.5° C] throughout the range of
30° F to 120° F [0° C to 50° C].
Question 3
How often must the temperature measuring device be calibrated?
A) Monthly
B) Semi-annually
C) Annually
D) Every two years
E) Only when the battery is changed
Correct Answer: C) Annually
Rationale: ASTM C1064 specifies that the device must be calibrated annually or whenever
there is a question of accuracy to ensure the reliability of the field data.
Question 4
In which of the following containers or locations is it acceptable to measure the temperature of
freshly mixed concrete?
, 2
A) A wheelbarrow
B) A wall form
C) The discharge stream of a mixer
D) A concrete bucket
E) All of the above
Correct Answer: E) All of the above
Rationale: The temperature can be measured in any container or location as long as there is
at least 3 inches of concrete cover in all directions around the sensor and the sample is
representative.
Question 5
Is a composite sample of concrete required by ASTM C172 if the only purpose for obtaining the
sample is to determine the temperature?
A) Yes, a composite sample is always required for any test.
B) No, a composite sample is not required for temperature tests.
C) Yes, but only if the concrete contains air-entraining admixtures.
D) No, unless the concrete has a slump greater than 4 inches.
E) Yes, but only if the temperature is above 90° F.
Correct Answer: B) No, a composite sample is not required for temperature tests.
Rationale: ASTM C1064 allows for the temperature to be taken from a single portion of the
batch, provided the sensor has adequate cover; a full composite sample per ASTM C172 is
not mandatory for temperature alone.
Question 6
What preparation must be performed on the sample container prior to sampling the concrete for a
temperature test?
A) It must be bone dry.
B) It must be heated to the expected concrete temperature.
C) It must be dampened with water.
D) It must be coated with a release agent.
E) No preparation is required.
Correct Answer: C) Dampen (with water)
Rationale: The container should be dampened to prevent it from absorbing moisture from
the concrete sample, which could affect the properties and the temperature reading.
Question 7
After submerging the temperature measuring device in the concrete, what action should the
technician take regarding the concrete surrounding the device?
A) Rod the concrete 25 times.
B) Tap the sides of the container with a mallet.
C) Gently press the concrete around the device at the surface.
, 3
D) Vibrate the concrete for 5 seconds.
E) Stir the concrete with the sensor.
Correct Answer: C) Gently press the concrete around the temperature measuring device at
the surface of the concrete
Rationale: Gently pressing the concrete around the sensor ensures that the ambient air
temperature does not affect the sensor and that there is full contact between the concrete
and the measuring device.
Question 8
What is the required duration for the temperature measuring device to remain in the freshly
mixed concrete?
A) Exactly 1 minute
B) At least 2 minutes but not more than 5 minutes
C) At least 5 minutes
D) Until the reading stabilizes for 30 seconds
E) Exactly 10 minutes
Correct Answer: B) At least 2 minutes but not more than 5 minutes
Rationale: The device must remain in the concrete for a minimum of 2 minutes to allow for
stabilization, but not more than 5 minutes to avoid temperature changes caused by
hydration or ambient conditions.
Question 9
The temperature of the concrete must be reported to the nearest _________ degrees.
A) 0.1° F [0.1° C]
B) 0.5° F [0.2° C]
C) 1° F [0.5° C]
D) 2° F [1.0° C]
E) 5° F [2.5° C]
Correct Answer: C) 1 degree F [0.5 C]
Rationale: Standard reporting for ASTM C1064 requires the temperature to be rounded
and recorded to the nearest whole degree Fahrenheit or the nearest 0.5 degree Celsius.
Question 10
According to ASTM C1064, what is the primary reason for taking the temperature of freshly
mixed concrete?
A) To determine if the concrete will reach its 28-day strength.
B) To check for the presence of fly ash.
C) To verify conformance to a specified requirement for temperature.
D) To calculate the water-cement ratio.
E) To determine the setting time of the concrete.
Correct Answer: C) Verify conformance to a specified requirement for temperature of
, 4
concrete
Rationale: Project specifications often include a maximum or minimum allowable
temperature for concrete at the time of placement; C1064 provides the standardized
method to verify this compliance.
Question 11
Does ASTM C1064 specify a maximum allowable temperature for freshly mixed concrete?
A) Yes, 90° F [32° C].
B) Yes, 100° F [38° C].
C) No, a maximum temperature is not specified in the standard itself.
D) Yes, it depends on the cement type.
E) Yes, but only for mass concrete.
Correct Answer: C) False
Rationale: ASTM C1064 is a "how-to" method for measurement. The actual temperature
limits are found in the project specifications or other codes (like ACI 301), not within
C1064.
Question 12
Is it necessary to rod the concrete sample used for temperature determination 25 times?
A) Yes, to ensure consolidation.
B) No, rodding is not required for temperature determination.
C) Yes, but only if the slump is less than 1 inch.
D) No, it should be rodded 10 times.
E) Yes, only if using a metal container.
Correct Answer: B) False
Rationale: Rodding is not a part of the ASTM C1064 procedure. Consolidating the concrete
for a temperature test is not required and could potentially change the temperature
through friction or exposure.
Question 13
ASTM C172 (Sampling) is required when tests are being made to determine _________ with
specification requirements.
A) Profitability
B) Compliance
C) Aesthetic quality
D) Worker efficiency
E) Soil stability
Correct Answer: B) Compliance
Rationale: The standard practice for sampling is intended to ensure that the sample used for
testing is truly representative of the batch, allowing for an accurate determination of
compliance with project specifications.
