Practice Test Geeks(ATT) ACI Aggregate Testing Technician Practice Test
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Soundness & Durability Testing Flashcards

7 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. The Los Angeles abrasion test (ASTM C131/C535) measures aggregate resistance to:

    Answer: Degradation by abrasion and impact

    The LA abrasion test measures an aggregate's resistance to degradation by abrasion and impact using steel balls in a rotating drum.

  2. In the Los Angeles abrasion test, after rotation the aggregate is washed over which sieve to determine percent loss?

    Answer: No. 12 (1.70 mm)

    Material passing the No. 12 (1.70 mm) sieve after washing is considered loss in the LA abrasion test.

  3. ASTM C131 applies to coarse aggregate with particles predominantly retained on which sieve?

    Answer: 9.5 mm (⅜ in.)

    ASTM C131 covers smaller coarse aggregates predominantly retained on the 9.5 mm (⅜ in.) sieve, while C535 covers larger aggregates.

  4. In the Micro-Deval test (ASTM D6928), what abrasive medium is used with the aggregate sample?

    Answer: Steel balls and water

    The Micro-Deval test uses steel balls and water in a rotating drum to determine aggregate wear resistance.

  5. Which LA abrasion percent loss value represents BETTER aggregate quality?

    Answer: 25%

    A lower LA abrasion percent loss indicates a harder, more wear-resistant aggregate; 25% represents better quality than higher values.

  6. What is the typical maximum LA abrasion loss specified for coarse aggregate used in concrete pavement?

    Answer: 40%

    Most pavement specifications limit LA abrasion loss to 40% or less for coarse aggregate in concrete pavement applications.

  7. How does the Micro-Deval test differ from the LA abrasion test in terms of the degradation mechanism it emphasizes?

    Answer: Micro-Deval emphasizes wet abrasion/attrition while LA abrasion includes significant impact

    The Micro-Deval test emphasizes wet abrasion and attrition at lower energy, while the LA abrasion test includes significant impact from the steel balls and the shelf inside the drum.