Practice Test Geeks(ATT) ACI Aggregate Testing Technician Practice Test
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ATT Deleterious Materials & Clay Content Flashcards

6 cards from real ATT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

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  1. Which ASTM standard covers the test method for clay lumps and friable particles in aggregates?

    Answer: ASTM C142

    ASTM C142 is the standard test method for clay lumps and friable particles in aggregates.

  2. In the clay lumps and friable particles test (ASTM C142), the sample is soaked in water for a period of:

    Answer: 24 ± 4 hours

    ASTM C142 requires soaking the sample in water for 24 ± 4 hours before attempting to break particles with the fingers.

  3. After soaking in ASTM C142, how are clay lumps and friable particles identified?

    Answer: By attempting to crumble them between thumb and forefinger

    Particles that can be broken down by rubbing between the thumb and forefinger after soaking are classified as clay lumps or friable particles.

  4. According to ASTM C33, the maximum allowable clay lumps and friable particles in fine aggregate for concrete is:

    Answer: 3.0%

    ASTM C33 limits clay lumps and friable particles in fine aggregate to a maximum of 3.0% by mass.

  5. What sieve size is used to separate the material retained for the clay lumps test in coarse aggregate per ASTM C142?

    Answer: No. 4 (4.75 mm)

    For coarse aggregate, ASTM C142 testing uses material retained on the No. 4 (4.75 mm) sieve.

  6. Which deleterious substance in aggregate is most likely to cause unsightly staining and pop-outs in hardened concrete?

    Answer: Coal and lignite particles

    Coal and lignite particles can expand, cause pop-outs, and produce dark staining on the surface of hardened concrete.

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