Which clay type is most likely to experience significant volume changes?

High plasticity clay is the type most likely to experience significant volume changes due to its composition and properties. High plasticity clays, often referred to as expansive or shrink-swell clays, contain a high proportion of minerals such as montmorillonite, which allow them to absorb water and swell significantly when wet. Conversely, when these clays dry out, they shrink in volume.

This characteristic of high plasticity clay poses challenges in construction and engineering projects, as the resulting movement can lead to structural damage if not properly accounted for in design and materials selection. In contrast, low plasticity clays have less tendency to swell and shrink, making them more stable under varying moisture conditions. Sands and silts do not experience the same degree of volume change as clay, mainly because of their granular nature and inability to hold moisture in a manner that affects their volume significantly. Thus, high plasticity clay is recognized as particularly problematic in terms of volume changes, leading to the conclusion that it is the correct answer.