A clay-like soil that swells with an increase in moisture is referred to as a(n) ________.

A clay-like soil that swells with an increase in moisture is referred to as a(n) ________.

• A. Expansive soil
• B. Plastic soil
• C. Swelling clay
• D. Reactive soil

Answer: (A)

Expansive soils are clay-rich soils that increase in volume when they absorb water. This swelling occurs because expandable clay minerals (such as montmorillonite) take up water between their layers, causing the soil to expand. In earthmoving and construction, this behavior matters a lot because moisture changes can lead to heave, cracking, and movement of fills and foundations. That’s why the term for a clay-like soil that swells with moisture is expansive soil. While terms like swelling clay describe the behavior, and plastic or reactive soil are less precise in this context, expansive soil is the standard label.

Expansive soils are clay-rich soils that increase in volume when they absorb water. This swelling occurs because expandable clay minerals (such as montmorillonite) take up water between their layers, causing the soil to expand. In earthmoving and construction, this behavior matters a lot because moisture changes can lead to heave, cracking, and movement of fills and foundations. That’s why the term for a clay-like soil that swells with moisture is expansive soil. While terms like swelling clay describe the behavior, and plastic or reactive soil are less precise in this context, expansive soil is the standard label.