LATEST ACI AGGREGATE TESTING
TECHNICIAN (LEVELS 1 AND 2)
CERTIFICATION EXAM | Q&A WITH
RATIONALES
1. Which of the following is the primary reference for
obtaining a representative sample of aggregates in
the field?
A) ASTM C136
B) ASTM D75
C) ASTM C702
D) ASTM C117
Correct answer: B
Rationale: ASTM D75 (or AASHTO R 90) is the
standard practice for sampling aggregates from
various sources, including stockpiles, conveyors,
and trucks, to obtain a representative sample for
testing.
**2. According to ASTM D75, when sampling from a
stockpile, where should the sample be taken from?**
A) The top surface of the pile
,B) The sides of the pile only
C) The bottom of the pile only
D) Several locations around the pile, after removing
the surface layer
Correct answer: D
Rationale: ASTM D75 requires that the outer layer be
removed to avoid segregated surface material, and
samples be taken from several locations around the
pile to ensure representativeness.
**3. The primary purpose of ASTM C702 is to:**
A) Wash aggregate to remove fines
B) Reduce a field sample to a test‑sized sample
C) Determine the moisture content of aggregate
D) Measure the specific gravity of aggregate
Correct answer: B
Rationale: ASTM C702 covers the reduction of a
large aggregate sample to a smaller, test‑sized
sample using methods such as mechanical splitting
or quartering, while maintaining representativeness.
,**4. What is the minimum size of a representative
sample for coarse aggregate (maximum size 37.5
mm) when performing sieve analysis according to
ASTM C136?**
A) 1 kg
B) 5 kg
C) 10 kg
D) 25 kg
Correct answer: B
Rationale: ASTM C136 provides tables for minimum
sample mass based on nominal maximum aggregate
size. For 37.5 mm (1‑1/2 in), the minimum sample
mass is approximately 10 kg, but for many
procedures 5 kg may be sufficient; however, typical
practice is 10 kg.
**5. Which of the following best describes the
purpose of ASTM C117?**
A) To determine the particle size distribution of
aggregates by sieving
B) To determine the amount of material finer than a
No. 200 (75‑µm) sieve in aggregate by washing
, C) To determine the specific gravity of coarse
aggregate
D) To determine the organic impurities in fine
aggregate
Correct answer: B
Rationale: ASTM C117 (or AASHTO T 11) is used to
wash aggregate to separate and quantify the
amount of material that passes a No. 200 (75‑µm)
sieve.
**6. In ASTM C136, the sample for sieve analysis
must be oven‑dried to a constant mass at a
temperature of:**
A) 60 ± 5°C
B) 110 ± 5°C
C) 150 ± 5°C
D) 200 ± 5°C
Correct answer: B
Rationale: ASTM C136 specifies that the aggregate
sample shall be dried to constant mass at a
temperature of 110 ± 5°C (230 ± 9°F) before sieving.
TECHNICIAN (LEVELS 1 AND 2)
CERTIFICATION EXAM | Q&A WITH
RATIONALES
1. Which of the following is the primary reference for
obtaining a representative sample of aggregates in
the field?
A) ASTM C136
B) ASTM D75
C) ASTM C702
D) ASTM C117
Correct answer: B
Rationale: ASTM D75 (or AASHTO R 90) is the
standard practice for sampling aggregates from
various sources, including stockpiles, conveyors,
and trucks, to obtain a representative sample for
testing.
**2. According to ASTM D75, when sampling from a
stockpile, where should the sample be taken from?**
A) The top surface of the pile
,B) The sides of the pile only
C) The bottom of the pile only
D) Several locations around the pile, after removing
the surface layer
Correct answer: D
Rationale: ASTM D75 requires that the outer layer be
removed to avoid segregated surface material, and
samples be taken from several locations around the
pile to ensure representativeness.
**3. The primary purpose of ASTM C702 is to:**
A) Wash aggregate to remove fines
B) Reduce a field sample to a test‑sized sample
C) Determine the moisture content of aggregate
D) Measure the specific gravity of aggregate
Correct answer: B
Rationale: ASTM C702 covers the reduction of a
large aggregate sample to a smaller, test‑sized
sample using methods such as mechanical splitting
or quartering, while maintaining representativeness.
,**4. What is the minimum size of a representative
sample for coarse aggregate (maximum size 37.5
mm) when performing sieve analysis according to
ASTM C136?**
A) 1 kg
B) 5 kg
C) 10 kg
D) 25 kg
Correct answer: B
Rationale: ASTM C136 provides tables for minimum
sample mass based on nominal maximum aggregate
size. For 37.5 mm (1‑1/2 in), the minimum sample
mass is approximately 10 kg, but for many
procedures 5 kg may be sufficient; however, typical
practice is 10 kg.
**5. Which of the following best describes the
purpose of ASTM C117?**
A) To determine the particle size distribution of
aggregates by sieving
B) To determine the amount of material finer than a
No. 200 (75‑µm) sieve in aggregate by washing
, C) To determine the specific gravity of coarse
aggregate
D) To determine the organic impurities in fine
aggregate
Correct answer: B
Rationale: ASTM C117 (or AASHTO T 11) is used to
wash aggregate to separate and quantify the
amount of material that passes a No. 200 (75‑µm)
sieve.
**6. In ASTM C136, the sample for sieve analysis
must be oven‑dried to a constant mass at a
temperature of:**
A) 60 ± 5°C
B) 110 ± 5°C
C) 150 ± 5°C
D) 200 ± 5°C
Correct answer: B
Rationale: ASTM C136 specifies that the aggregate
sample shall be dried to constant mass at a
temperature of 110 ± 5°C (230 ± 9°F) before sieving.
