LATEST ACI CONCRETE FIELD TESTING
TECHNICIAN – GRADE I CERTIFICATION
EXAM | Q&A WITH RATIONALES
1. What is the primary purpose of the slump test
according to ASTM C143?
A) To determine the compressive strength of
concrete
B) To measure the water‑cement ratio of the mix
C) To assess the consistency or workability of fresh
concrete
D) To calculate the air content of the concrete
Correct answer: C
Rationale: The slump test measures the consistency
of fresh concrete, providing an indication of its
workability under field conditions.
2. According to ASTM C172, how often should
concrete be sampled from a revolving drum truck
mixer?
A) Only from the first portion of the discharge
,B) At two or more regularly spaced intervals during
discharge of the middle portion of the batch
C) Only from the last portion of the discharge
D) At the beginning and end of the discharge only
Correct answer: B
Rationale: ASTM C172 requires sampling at two or
more regularly spaced intervals during discharge of
the middle portion of the batch to ensure a
representative sample.
3. What is the minimum immersion depth for a
temperature measuring device in freshly mixed
concrete per ASTM C1064?
A) 1 in. (25 mm)
B) 2 in. (50 mm)
C) 3 in. (75 mm)
D) 4 in. (100 mm)
Correct answer: C
Rationale: The sensor of the temperature measuring
device must be submerged a minimum of 3 inches
(75 mm) into the freshly mixed concrete to ensure
accurate temperature measurement.
,4. How long must a temperature measuring device
remain in freshly mixed concrete before a reading is
taken?
A) At least 30 seconds but not more than 1 minute
B) At least 1 minute but not more than 2 minutes
C) At least 2 minutes but not more than 5 minutes
D) At least 5 minutes but not more than 10 minutes
Correct answer: C
Rationale: ASTM C1064 specifies that the
temperature measuring device must be left in the
concrete for at least 2 minutes but not more than 5
minutes to allow the temperature to stabilize.
5. According to ACI, how often must a temperature
measuring device be calibrated?
A) Monthly
B) Quarterly
C) Annually
D) Every five years
Correct answer: C
, Rationale: The temperature measuring device shall
be calibrated annually, or whenever there is a
question of accuracy.
6. A composite sample of concrete is always
required, even if the only purpose is to determine
temperature.
A) True
B) False
C) Only if the temperature exceeds 90°F
D) Only if multiple samples are being taken
Correct answer: B
Rationale: A composite sample is not required when
the only test to be performed is the temperature
test; a single grab sample is acceptable.
7. Which of the following materials is acceptable as a
container for a concrete sample?
A) A dry wooden wheelbarrow
B) A dampened metal sampling container
C) A plastic bucket with standing water
D) A cardboard box
TECHNICIAN – GRADE I CERTIFICATION
EXAM | Q&A WITH RATIONALES
1. What is the primary purpose of the slump test
according to ASTM C143?
A) To determine the compressive strength of
concrete
B) To measure the water‑cement ratio of the mix
C) To assess the consistency or workability of fresh
concrete
D) To calculate the air content of the concrete
Correct answer: C
Rationale: The slump test measures the consistency
of fresh concrete, providing an indication of its
workability under field conditions.
2. According to ASTM C172, how often should
concrete be sampled from a revolving drum truck
mixer?
A) Only from the first portion of the discharge
,B) At two or more regularly spaced intervals during
discharge of the middle portion of the batch
C) Only from the last portion of the discharge
D) At the beginning and end of the discharge only
Correct answer: B
Rationale: ASTM C172 requires sampling at two or
more regularly spaced intervals during discharge of
the middle portion of the batch to ensure a
representative sample.
3. What is the minimum immersion depth for a
temperature measuring device in freshly mixed
concrete per ASTM C1064?
A) 1 in. (25 mm)
B) 2 in. (50 mm)
C) 3 in. (75 mm)
D) 4 in. (100 mm)
Correct answer: C
Rationale: The sensor of the temperature measuring
device must be submerged a minimum of 3 inches
(75 mm) into the freshly mixed concrete to ensure
accurate temperature measurement.
,4. How long must a temperature measuring device
remain in freshly mixed concrete before a reading is
taken?
A) At least 30 seconds but not more than 1 minute
B) At least 1 minute but not more than 2 minutes
C) At least 2 minutes but not more than 5 minutes
D) At least 5 minutes but not more than 10 minutes
Correct answer: C
Rationale: ASTM C1064 specifies that the
temperature measuring device must be left in the
concrete for at least 2 minutes but not more than 5
minutes to allow the temperature to stabilize.
5. According to ACI, how often must a temperature
measuring device be calibrated?
A) Monthly
B) Quarterly
C) Annually
D) Every five years
Correct answer: C
, Rationale: The temperature measuring device shall
be calibrated annually, or whenever there is a
question of accuracy.
6. A composite sample of concrete is always
required, even if the only purpose is to determine
temperature.
A) True
B) False
C) Only if the temperature exceeds 90°F
D) Only if multiple samples are being taken
Correct answer: B
Rationale: A composite sample is not required when
the only test to be performed is the temperature
test; a single grab sample is acceptable.
7. Which of the following materials is acceptable as a
container for a concrete sample?
A) A dry wooden wheelbarrow
B) A dampened metal sampling container
C) A plastic bucket with standing water
D) A cardboard box
