ACI CLTT-2 study guide
ACI CLTT-2 · Work through your exam, one topic at a time.
The ACI Concrete Laboratory Testing Technician – Level 2 is the second tier of the American Concrete Institute's Laboratory Concrete Testing certification track, listed by ACI alongside the Level 1 credential and the Concrete Strength Testing Technician program. ACI describes its testing programs as assessing the knowledge and ability to perform, record, and report the results of concrete field and laboratory tests, so this credential targets technicians who already handle laboratory concrete work and want a recognized qualification for the tests they run and the results they report. Certification exams and optional training courses are delivered through an international network of over 135 sponsoring groups, which means scheduling, training availability, and site logistics are handled locally rather than by a single central office. Preparation should center on the test methods you will actually perform: read each procedure end to end, practice the steps in a working laboratory with calibrated equipment, and rehearse recording and reporting results in the required format. The ACI CLTT-2 study guide has 2 sections and about 732 words.
01Laboratory Concrete Testing: Control, Conditioning, and Calculation
A concrete test result is only as good as the chain of custody behind it. Candidates must understand sampling (representative sample, more than one increment, remixing before testing), specimen preparation (mold type, number of layers and rod blows, consolidation by vibration for low-slump or stiff mixes), and curing/conditioning (standard moist curing, or job-site curing when the question asks about the structure rather than the potential of the mix).
362 words, about 2 min02Aggregate Testing: Sampling, Grading, and Physical Properties
Aggregates make up the majority of concrete volume, so their grading, shape, and absorption drive workability, water demand, and durability. Candidates must know the standard test families: sieve analysis and fineness modulus, moisture content and absorption, bulk specific gravity (oven-dry, saturated-surface-dry, and apparent), unit weight and voids, and soundness or abrasion resistance for durability screening.
370 words, about 2 min