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Sieve Analysis & Gradation 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. According to ASTM C136, the minimum sample mass for sieve analysis of a coarse aggregate with a nominal maximum size of 1½ in. (37.5 mm) is approximately:

    Answer: 15 kg (33 lb)

    ASTM C136 Table 2 requires approximately 15 kg for nominal maximum size of 37.5 mm (1½ in.) to ensure a representative sample.

  2. On a gradation chart, a well-graded aggregate will appear as:

    Answer: A relatively smooth S-shaped curve spanning a wide range of sizes

    A well-graded aggregate has particles distributed across a wide range of sizes, producing a smooth S-shaped curve on a percent-passing gradation chart.

  3. When combining two aggregate stockpiles to achieve a desired gradation, the method used to calculate the blend proportions is called:

    Answer: The diagonal method or trial-and-error blending

    Aggregate blending typically uses the diagonal method (graphical) or trial-and-error calculations to determine proportions that meet specification gradation limits.

  4. The percent retained on a given sieve is calculated by dividing the mass retained on that sieve by:

    Answer: The total original dry sample mass

    Percent retained = (mass retained on sieve / total original dry sample mass) × 100, using the total original sample as the denominator.

  5. ASTM C33 specifies gradation requirements for concrete aggregates. For coarse aggregate Size No. 57, the nominal size range is:

    Answer: 1 in. to No. 4 (25.0 mm to 4.75 mm)

    ASTM C33 Size No. 57 coarse aggregate has a nominal size range of 1 in. to No. 4 (25.0 mm to 4.75 mm).

  6. During a mechanical sieve shaker operation per ASTM C136, the recommended shaking duration is:

    Answer: Until no further separation is observed, typically verified manually

    ASTM C136 requires sieving until no more than 1% of the residue on any sieve passes during 1 minute of hand sieving, regardless of shaker time used.

  7. If the cumulative percent passing values sum to exactly 100% at each sieve from top to bottom, this indicates:

    Answer: Normal results — cumulative percent passing always totals 100% at the finest sieve

    In a correctly computed sieve analysis, 100% of the sample passes through the top (largest) sieve conceptually, and the cumulative percent passing the finest sieve should equal 100% minus the percent retained on the pan.