ACI Aggregate Level 2 study guide
ACI Aggregate Level 2 · Work through your exam, one topic at a time.
The ACI Aggregate Testing Technician-Level 2 is one of the certification programs administered by the American Concrete Institute, listed on ACI's Certification Programs page under the Aggregate Testing category alongside Aggregate Testing Technician-Level 1. ACI describes its certification offerings as "designed to form a minimum qualification for personnel employed within the concrete construction industry," and examinations are delivered through an international network of sponsoring groups. This page is an independent study resource; it is not affiliated with, endorsed by, or sponsored by ACI. The credential targets technicians and laboratory personnel who already perform aggregate sampling and testing and want documented evidence of their competence. Because this is the second tier of the aggregate testing track, candidates should be comfortable with routine aggregate test procedures, careful specimen handling, and accurate recording and reporting of results before attempting it. ACI's site groups its testing programs around the ability to "perform, record, and report the results of concrete field/laboratory tests," which is a fair description of what a Level 2 candidate is expected to demonstrate. Topics on this exam: Aggregate Testing (Level 2) and Aggregate Base Testing. The ACI Aggregate Level 2 study guide has 2 sections and about 755 words.
01Aggregate Testing at Level 2: Sampling, Gradation, and Quality Tests
Level 2 aggregate testing assumes you can run routine tests and also judge whether results are valid. Core concepts: representative sampling, moisture and density relationships, sieve analysis and gradation control, and durability/quality indices. Every result is only as good as the sample. Know that samples must be taken from the full cross-section of a stockpile or stream, never from the surface, and that a sample reduced by quartering or a mechanical splitter must remain representative.
399 words, about 2 min02Aggregate Base Testing: Compaction, Strength, and Acceptance
Aggregate base testing focuses on whether the placed layer meets density, gradation, and strength requirements. Level 2 candidates should connect laboratory results to field acceptance decisions. The laboratory reference is a moisture-density curve giving maximum dry density and optimum moisture content. Field density is measured and expressed as a percentage of that maximum.
356 words, about 2 minMore study resources for ACI Aggregate Level 2
- Practice questionsAccording to standard practice, what is the nominal maximum size of aggregate defined as?
- FlashcardsFineness modulus. Sum of cumulative percent retained on the 4.75, 2.36, 1.18, 0.600, 0.300, and 0.150 mm sieves divided by 100.
- Cheat sheetSieve analysis: percent passing = (mass passing sieve / total dry mass) × 100; cumulative retained is subtracted from 100 to get percent passing.
- Key termsSieve Analysis. A test that shakes a dried aggregate sample through a stack of sieves with progressively smaller openings to determine how much material is retained on each sieve and to calculate the gradation.
- Study planDefine the scope of Aggregate Testing (Level 2) and list every test method it covers.
- Common mistakesCandidates copy the habit of rounding from field work and assume 'close enough' is acceptable, when the test method requires recording to the sensitivity of the balance used.
- Exam-day guideBring the exact ID name that matches your registration.