Which term refers to the measure of water content in compacted soil that affects pliability?

Which term refers to the measure of water content in compacted soil that affects pliability?

• A. Crystalline
• B. Plasticity index
• C. Riprap
• D. Backhauling

Answer: (B)

Plasticity index describes how water content affects a soil’s ability to be molded, i.e., its pliability. It’s found by taking the difference between the liquid limit (water content at which soil acts like a liquid) and the plastic limit (water content at which soil begins to crumble and becomes brittle). The larger this difference, the more plastic the soil is, meaning it can be molded more easily within that moisture range. In compacted soil, a higher plasticity index indicates greater pliability under typical moisture conditions, but also greater sensitivity to changes in water content. The other terms don’t relate to moisture-driven pliability: crystalline refers to mineral structure, riprap is large rock used for erosion control, and backhauling is hauling material back to a destination.

Plasticity index describes how water content affects a soil’s ability to be molded, i.e., its pliability. It’s found by taking the difference between the liquid limit (water content at which soil acts like a liquid) and the plastic limit (water content at which soil begins to crumble and becomes brittle). The larger this difference, the more plastic the soil is, meaning it can be molded more easily within that moisture range. In compacted soil, a higher plasticity index indicates greater pliability under typical moisture conditions, but also greater sensitivity to changes in water content. The other terms don’t relate to moisture-driven pliability: crystalline refers to mineral structure, riprap is large rock used for erosion control, and backhauling is hauling material back to a destination.