Practice Test Geeks(NETTCP) New England Transportation Technician Certification Program Practice Test
← All NETTCP Flashcard Decks

Soils and Aggregates Flashcards

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

Read the first 7 Soils and Aggregates flashcards as text

  1. What does the term 'well-graded' mean when describing aggregate gradation?

    Answer: Particle sizes are distributed across a wide range with few gaps

    Well-graded aggregate has a continuous distribution of particle sizes that allows smaller particles to fill voids between larger ones, improving density and stability.

  2. In New England transportation projects, frost depth considerations are critical because:

    Answer: Freeze-thaw cycles cause heave and subgrade weakening during spring thaw

    In New England's cold climate, frost penetrates deep into pavement structures, and spring thaw weakens saturated subgrades causing pavement heave and failure.

  3. Which field test provides a quick assessment of subgrade bearing capacity during construction?

    Answer: Dynamic Cone Penetrometer (DCP) test

    The Dynamic Cone Penetrometer provides a rapid in-situ measure of subgrade strength by tracking penetration rate per blow, correlating to CBR values.

  4. Organic soils are generally considered poor subgrade materials primarily because:

    Answer: They compress significantly under load and have low shear strength

    Organic soils compress significantly under load due to decomposable material, resulting in excessive long-term settlement and insufficient bearing capacity.

  5. The purpose of a geotextile fabric placed between subgrade and base course is to:

    Answer: Provide separation, filtration, and prevent subgrade intrusion into base

    Geotextile fabric separates weak subgrade from the aggregate base, prevents intermixing, and allows drainage while maintaining structural integrity.

  6. When aggregate is described as having 'angular' particles, this shape characteristic typically:

    Answer: Increases interlocking and shear strength compared to rounded particles

    Angular aggregate particles interlock mechanically, increasing internal friction angle and shear strength, which is beneficial for base and surface course stability.

  7. A soil with a liquid limit of 55 and a plasticity index of 30 would be classified under AASHTO as:

    Answer: A-7-6 (plastic clay)

    With LL > 41 and PI > 11, and PI exceeding LL minus 30, the soil plots as A-7-6, indicating highly plastic clay.