ACI AGGREGATE TESTING TECHNICIAN — LEVEL 1
— SECTION 4 EXAM Actual Exam Complete
Questions and Answers Detailed Rationales Pass
Guaranteed - A+ Graded
══════════════════════════════════════
SECTION 1: SAMPLING AGGREGATES (ASTM D75 / AASHTO T2) Q1 – Q10
══════════════════════════════════════
Question 1 of 50
A technician is sampling coarse aggregate from a stockpile at a ready-mix concrete
plant. The aggregate is a 3/4-inch nominal maximum size crushed limestone. The
technician uses a shovel to collect material from three locations around the base of the
stockpile. What is the primary error in this sampling method?
A. The sample size is too small for 3/4-inch aggregate
B. The technician failed to use a mechanical sampling device
C. The sample was taken only from the base of the stockpile, which may not represent
the entire lot due to segregation ✓ CORRECT
D. The shovel is not an approved sampling tool per ASTM D75
Correct Answer: C
Rationale: ASTM D75 requires sampling from multiple locations and elevations across
the stockpile to obtain a representative sample, as segregation causes larger particles
to concentrate at the base and fines at the top. Option A is incorrect because sample
size is determined by nominal maximum aggregate size, not the number of locations
alone. Stockpile segregation is one of the most common sources of non-representative
samples in aggregate testing.
,Question 2 of 50
A quality control technician needs to obtain a sample of fine aggregate from a conveyor
belt at an asphalt plant. The belt is moving at 200 feet per minute and the aggregate is
AASHTO No. 10 screenings. Which sampling procedure conforms to AASHTO T2?
A. Scoop a single sample from the end of the conveyor discharge chute
B. Collect a full cross-section of material from the moving belt using an approved
sampling frame or device ✓ CORRECT
C. Take three random handfuls from the top of the aggregate pile at the end of the belt
D. Sample only during the first 10 minutes of production each day
Correct Answer: B
Rationale: AASHTO T2 specifies that conveyor belt samples must represent a full
cross-section of the material stream, obtained using an approved sampling frame or
device that captures all particle sizes equally. Option A is incorrect because discharge
chute samples may not represent the full stream cross-section and are prone to
segregation. Belt sampling is the most reliable method for continuous production
monitoring.
Question 3 of 50
A laboratory receives a 150-pound sample of coarse aggregate for testing. The
technician needs to reduce this sample to the required test size of 25 pounds for sieve
analysis. Which sample reduction method is acceptable per ASTM D75?
A. Quartering the sample on a clean, hard, level surface using a straightedge and shovel
✓ CORRECT
B. Pouring the sample through a funnel and collecting every other handful
C. Scooping material only from the center of the sample pile
D. Splitting the sample using a riffle splitter with 3/4-inch openings for fine aggregate
Correct Answer: A
,Rationale: ASTM D75 permits quartering on a clean, hard, level surface as an acceptable
sample reduction method when a mechanical splitter is unavailable or impractical for
the aggregate size. Option D is incorrect because a riffle splitter with 3/4-inch openings
is too large for fine aggregate and would not properly reduce the sample. Quartering
requires careful technique to avoid bias from segregation.
Question 4 of 50
A technician is sampling aggregate from a truckload delivery at a construction site. The
load contains approximately 25 tons of 1-inch nominal maximum size crushed gravel.
According to ASTM D75, what is the minimum number of samples that should be
obtained from this single truckload?
A. One composite sample from the top of the load only
B. Two samples, one from the front and one from the rear of the truck bed
C. One sample is sufficient for any truckload under 50 tons
D. Multiple increments from various locations within the load to form a composite
sample ✓ CORRECT
Correct Answer: D
Rationale: ASTM D75 requires multiple increments from various locations within a
truckload to form a composite sample that accounts for segregation and variability
within the load. Option A is incorrect because sampling only from the top of the load
fails to capture material from the middle and bottom where segregation may differ.
Proper truck sampling prevents acceptance of non-specification material hidden within
the load.
Question 5 of 50
A field technician collects a sample of fine aggregate from a stockpile during a
rainstorm. The sample is placed in a sealed plastic bag and transported to the
, laboratory. Upon arrival, the sample weighs 52 pounds and appears visibly wet. Which
action is required before proceeding with moisture content testing?
A. Begin testing immediately because the sealed bag preserved the original moisture
B. Air-dry the sample to a constant mass before determining moisture content
C. Record the as-received condition and test for total moisture content as delivered ✓
CORRECT
D. Discard the sample and collect a new one during dry weather
Correct Answer: C
Rationale: ASTM D75 requires documenting the as-received condition and testing for
total moisture content as delivered when samples are collected during wet conditions,
because the moisture condition at sampling represents the actual field condition.
Option B would alter the sample's moisture state and provide misleading results for
payment or mix design purposes. Rain-affected samples are valid for testing if properly
documented.
Question 6 of 50
A technician needs to obtain a sample from a flowing stream of aggregate at a sand
and gravel operation. The material is a blend of fine and coarse aggregate with a
nominal maximum size of 1-1/2 inches. Which sampling device is most appropriate per
AASHTO T2?
A. A sampling thief inserted into a stationary pile
B. A sampling frame or sampling tube capable of collecting a full cross-section of the
stream ✓ CORRECT
C. A hand scoop used to grab material from the side of the conveyor
D. A quartering template placed on the ground below the discharge
Correct Answer: B
Rationale: AASHTO T2 requires a sampling frame or tube that captures a full
cross-section of the material stream for flowing aggregate, ensuring all particle sizes
— SECTION 4 EXAM Actual Exam Complete
Questions and Answers Detailed Rationales Pass
Guaranteed - A+ Graded
══════════════════════════════════════
SECTION 1: SAMPLING AGGREGATES (ASTM D75 / AASHTO T2) Q1 – Q10
══════════════════════════════════════
Question 1 of 50
A technician is sampling coarse aggregate from a stockpile at a ready-mix concrete
plant. The aggregate is a 3/4-inch nominal maximum size crushed limestone. The
technician uses a shovel to collect material from three locations around the base of the
stockpile. What is the primary error in this sampling method?
A. The sample size is too small for 3/4-inch aggregate
B. The technician failed to use a mechanical sampling device
C. The sample was taken only from the base of the stockpile, which may not represent
the entire lot due to segregation ✓ CORRECT
D. The shovel is not an approved sampling tool per ASTM D75
Correct Answer: C
Rationale: ASTM D75 requires sampling from multiple locations and elevations across
the stockpile to obtain a representative sample, as segregation causes larger particles
to concentrate at the base and fines at the top. Option A is incorrect because sample
size is determined by nominal maximum aggregate size, not the number of locations
alone. Stockpile segregation is one of the most common sources of non-representative
samples in aggregate testing.
,Question 2 of 50
A quality control technician needs to obtain a sample of fine aggregate from a conveyor
belt at an asphalt plant. The belt is moving at 200 feet per minute and the aggregate is
AASHTO No. 10 screenings. Which sampling procedure conforms to AASHTO T2?
A. Scoop a single sample from the end of the conveyor discharge chute
B. Collect a full cross-section of material from the moving belt using an approved
sampling frame or device ✓ CORRECT
C. Take three random handfuls from the top of the aggregate pile at the end of the belt
D. Sample only during the first 10 minutes of production each day
Correct Answer: B
Rationale: AASHTO T2 specifies that conveyor belt samples must represent a full
cross-section of the material stream, obtained using an approved sampling frame or
device that captures all particle sizes equally. Option A is incorrect because discharge
chute samples may not represent the full stream cross-section and are prone to
segregation. Belt sampling is the most reliable method for continuous production
monitoring.
Question 3 of 50
A laboratory receives a 150-pound sample of coarse aggregate for testing. The
technician needs to reduce this sample to the required test size of 25 pounds for sieve
analysis. Which sample reduction method is acceptable per ASTM D75?
A. Quartering the sample on a clean, hard, level surface using a straightedge and shovel
✓ CORRECT
B. Pouring the sample through a funnel and collecting every other handful
C. Scooping material only from the center of the sample pile
D. Splitting the sample using a riffle splitter with 3/4-inch openings for fine aggregate
Correct Answer: A
,Rationale: ASTM D75 permits quartering on a clean, hard, level surface as an acceptable
sample reduction method when a mechanical splitter is unavailable or impractical for
the aggregate size. Option D is incorrect because a riffle splitter with 3/4-inch openings
is too large for fine aggregate and would not properly reduce the sample. Quartering
requires careful technique to avoid bias from segregation.
Question 4 of 50
A technician is sampling aggregate from a truckload delivery at a construction site. The
load contains approximately 25 tons of 1-inch nominal maximum size crushed gravel.
According to ASTM D75, what is the minimum number of samples that should be
obtained from this single truckload?
A. One composite sample from the top of the load only
B. Two samples, one from the front and one from the rear of the truck bed
C. One sample is sufficient for any truckload under 50 tons
D. Multiple increments from various locations within the load to form a composite
sample ✓ CORRECT
Correct Answer: D
Rationale: ASTM D75 requires multiple increments from various locations within a
truckload to form a composite sample that accounts for segregation and variability
within the load. Option A is incorrect because sampling only from the top of the load
fails to capture material from the middle and bottom where segregation may differ.
Proper truck sampling prevents acceptance of non-specification material hidden within
the load.
Question 5 of 50
A field technician collects a sample of fine aggregate from a stockpile during a
rainstorm. The sample is placed in a sealed plastic bag and transported to the
, laboratory. Upon arrival, the sample weighs 52 pounds and appears visibly wet. Which
action is required before proceeding with moisture content testing?
A. Begin testing immediately because the sealed bag preserved the original moisture
B. Air-dry the sample to a constant mass before determining moisture content
C. Record the as-received condition and test for total moisture content as delivered ✓
CORRECT
D. Discard the sample and collect a new one during dry weather
Correct Answer: C
Rationale: ASTM D75 requires documenting the as-received condition and testing for
total moisture content as delivered when samples are collected during wet conditions,
because the moisture condition at sampling represents the actual field condition.
Option B would alter the sample's moisture state and provide misleading results for
payment or mix design purposes. Rain-affected samples are valid for testing if properly
documented.
Question 6 of 50
A technician needs to obtain a sample from a flowing stream of aggregate at a sand
and gravel operation. The material is a blend of fine and coarse aggregate with a
nominal maximum size of 1-1/2 inches. Which sampling device is most appropriate per
AASHTO T2?
A. A sampling thief inserted into a stationary pile
B. A sampling frame or sampling tube capable of collecting a full cross-section of the
stream ✓ CORRECT
C. A hand scoop used to grab material from the side of the conveyor
D. A quartering template placed on the ground below the discharge
Correct Answer: B
Rationale: AASHTO T2 requires a sampling frame or tube that captures a full
cross-section of the material stream for flowing aggregate, ensuring all particle sizes
