ACI AGGREGATE TESTING TECHNICIAN - LEVEL 1 - SAMPLE WRITTEN EXAM
2026/2027
American Concrete Institute (ACI) Aggregate Testing Technician - Level 1 Certification |
Core Domains: Aggregate Sampling & Sample Reduction, Sieve Analysis & Gradation, Specific
Gravity & Absorption Tests, Material Finer than No. 200 Sieve, Clay Lumps & Friable Particles,
Lightweight Pieces in Aggregate, Organic Impurities, and Soundness & Degradation Tests |
Construction Materials Testing Focus
Exam Structure The ACI Aggregate Testing Technician - Level 1 Sample Written Exam for the
2026/2027 certification cycle is a representative 40-question assessment covering theoretical knowledge
and practical understanding of standardized test methods for aggregates as specified by ASTM and
AASHTO.
Introduction
This ACI Aggregate Testing Technician - Level 1 Sample Exam for the 2026/2027 academic year provides
practice with the written examination component required for certification. It tests knowledge of proper
procedures, calculations, and material specifications essential for conducting quality control tests on
coarse and fine aggregates used in concrete construction.
Answer Format
All correct testing procedures, calculations, and specification requirements must be presented in bold
and green, followed by detailed rationales that reference specific ASTM/AASHTO test designations,
standard practices, and the technical principles governing each aggregate property evaluation.
Table of Contents
Section 1: Aggregate Sampling & Sample Reduction (Questions 1-8)
Section 2: Sieve Analysis & Gradation (Questions 9-16)
Section 3: Specific Gravity & Absorption Tests (Questions 17-24)
Section 4: Material Finer than No. 200 Sieve (Questions 25-28)
Section 5: Clay Lumps & Friable Particles (Questions 29-32)
Section 6: Lightweight Pieces, Organic Impurities & Soundness (Questions 33-40)
Section 1: Aggregate Sampling & Sample Reduction
, Question 1: According to ASTM D75, what is the minimum size of a field sample for coarse aggregate
with a maximum size of 1.5 inches?
A) 50 lb
B) 100 lb
C) 200 lb
D) 300 lb
Correct Answer: C) 200 lb
Explanation: ASTM D75 Table 1 specifies that for coarse aggregate with a nominal maximum size of
1.5 inches (37.5 mm), the minimum field sample mass is 200 lb (90 kg). This ensures the sample is
representative of the entire lot and contains sufficient material for all required tests.
Question 2: Which method is NOT acceptable for reducing a field sample to a test sample according to
ASTM D75?
A) Quartering
B) Use of a mechanical splitter
C) Cone and quartering with a scoop
D) Hand-picking representative pieces
Correct Answer: D) Hand-picking representative pieces
Explanation: ASTM D75 explicitly prohibits hand-picking because it introduces bias and does not
ensure a representative sample. Acceptable methods include mechanical splitting (preferred) and
quartering (cone and quarter method), which randomly divide the sample to maintain
representativeness.
Question 3: What is the primary purpose of sample reduction in aggregate testing?
A) To reduce testing costs
B) To obtain a representative test sample of appropriate size
C) To eliminate oversized particles
D) To dry the sample more quickly
Correct Answer: B) To obtain a representative test sample of appropriate size
Explanation: Sample reduction ensures that the test portion accurately represents the entire field
sample while being small enough to handle in laboratory equipment. Proper reduction maintains
the same particle size distribution as the original sample, which is critical for valid test results.
Question 4: When using a mechanical splitter for sample reduction, what is the minimum number of
chutes required?
A) 2
B) 4
2026/2027
American Concrete Institute (ACI) Aggregate Testing Technician - Level 1 Certification |
Core Domains: Aggregate Sampling & Sample Reduction, Sieve Analysis & Gradation, Specific
Gravity & Absorption Tests, Material Finer than No. 200 Sieve, Clay Lumps & Friable Particles,
Lightweight Pieces in Aggregate, Organic Impurities, and Soundness & Degradation Tests |
Construction Materials Testing Focus
Exam Structure The ACI Aggregate Testing Technician - Level 1 Sample Written Exam for the
2026/2027 certification cycle is a representative 40-question assessment covering theoretical knowledge
and practical understanding of standardized test methods for aggregates as specified by ASTM and
AASHTO.
Introduction
This ACI Aggregate Testing Technician - Level 1 Sample Exam for the 2026/2027 academic year provides
practice with the written examination component required for certification. It tests knowledge of proper
procedures, calculations, and material specifications essential for conducting quality control tests on
coarse and fine aggregates used in concrete construction.
Answer Format
All correct testing procedures, calculations, and specification requirements must be presented in bold
and green, followed by detailed rationales that reference specific ASTM/AASHTO test designations,
standard practices, and the technical principles governing each aggregate property evaluation.
Table of Contents
Section 1: Aggregate Sampling & Sample Reduction (Questions 1-8)
Section 2: Sieve Analysis & Gradation (Questions 9-16)
Section 3: Specific Gravity & Absorption Tests (Questions 17-24)
Section 4: Material Finer than No. 200 Sieve (Questions 25-28)
Section 5: Clay Lumps & Friable Particles (Questions 29-32)
Section 6: Lightweight Pieces, Organic Impurities & Soundness (Questions 33-40)
Section 1: Aggregate Sampling & Sample Reduction
, Question 1: According to ASTM D75, what is the minimum size of a field sample for coarse aggregate
with a maximum size of 1.5 inches?
A) 50 lb
B) 100 lb
C) 200 lb
D) 300 lb
Correct Answer: C) 200 lb
Explanation: ASTM D75 Table 1 specifies that for coarse aggregate with a nominal maximum size of
1.5 inches (37.5 mm), the minimum field sample mass is 200 lb (90 kg). This ensures the sample is
representative of the entire lot and contains sufficient material for all required tests.
Question 2: Which method is NOT acceptable for reducing a field sample to a test sample according to
ASTM D75?
A) Quartering
B) Use of a mechanical splitter
C) Cone and quartering with a scoop
D) Hand-picking representative pieces
Correct Answer: D) Hand-picking representative pieces
Explanation: ASTM D75 explicitly prohibits hand-picking because it introduces bias and does not
ensure a representative sample. Acceptable methods include mechanical splitting (preferred) and
quartering (cone and quarter method), which randomly divide the sample to maintain
representativeness.
Question 3: What is the primary purpose of sample reduction in aggregate testing?
A) To reduce testing costs
B) To obtain a representative test sample of appropriate size
C) To eliminate oversized particles
D) To dry the sample more quickly
Correct Answer: B) To obtain a representative test sample of appropriate size
Explanation: Sample reduction ensures that the test portion accurately represents the entire field
sample while being small enough to handle in laboratory equipment. Proper reduction maintains
the same particle size distribution as the original sample, which is critical for valid test results.
Question 4: When using a mechanical splitter for sample reduction, what is the minimum number of
chutes required?
A) 2
B) 4
