Practice Test Geeks(ATT) ACI Aggregate Testing Technician Practice Test
← All ATT Flashcard Decks

Bulk Density, Voids & Organic Impurities 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.

Read the first 7 Bulk Density, Voids & Organic Impurities flashcards as text

  1. Which ASTM standard governs the Organic Impurities in Fine Aggregates for Concrete test?

    Answer: ASTM C40

    ASTM C40 is the standard test method for organic impurities in fine aggregates for concrete.

  2. In the ASTM C29 jigging method, how many times is each side of the measure raised and dropped per layer?

    Answer: 50 times

    The jigging method requires each side of the measure to be raised approximately 50 mm (2 in) and dropped 50 times per layer.

  3. If the liquid color in an ASTM C40 test is lighter than the reference standard, what does this indicate?

    Answer: The aggregate likely has acceptable organic impurity levels

    A color lighter than Organic Plate No. 3 indicates the fine aggregate likely does not contain harmful levels of organic impurities.

  4. The reference color in the ASTM C40 organic impurities test is equivalent to Gardner Color Standard No.:

    Answer: 11

    Organic Plate No. 3 (the reference standard for ASTM C40) is equivalent to Gardner Color Standard No. 11.

  5. What is the diameter of the tamping rod specified in ASTM C29?

    Answer: 16 mm (5/8 in)

    ASTM C29 specifies a smooth, straight steel tamping rod 16 mm (5/8 in) in diameter and approximately 600 mm (24 in) in length.

  6. The jigging method in ASTM C29 is appropriate for aggregates with maximum particle sizes between:

    Answer: 1-1/2 in (37.5 mm) and 3 in (75 mm)

    The jigging method is used for aggregates with maximum particle sizes greater than 37.5 mm (1-1/2 in) and up to 75 mm (3 in).

  7. What shape is the working end of the tamping rod specified in ASTM C29?

    Answer: Hemispherical

    ASTM C29 requires one end of the tamping rod to be hemispherical in shape to prevent breaking aggregate particles during compaction.