What is gravel in the context of construction materials?

Gravel is recognized as a coarse aggregate in construction, primarily derived from the natural disintegration and abrasion of rocks. This natural process results in angular or rounded particles that vary in size, typically ranging from 4.75 mm to 75 mm in diameter. In concrete mixtures, gravel serves as a vital component, providing strength and stability to the resulting material.

In the context of construction, gravel is favored for its excellent drainage capabilities and its ability to support structural loads when used in foundations, sub-bases, and other applications. The use of gravel as a coarse aggregate is essential in achieving the desired properties of concrete, including workability, durability, and resistance to freeze-thaw cycles.

Other options do not accurately define gravel in this context. The type of cement used in concrete refers to a completely different material that binds aggregates together, while chemical additives involve substances that enhance specific properties of concrete. Lightweight insulation material represents a different category of construction materials altogether, further distinguishing gravel's unique role as a coarse aggregate derived from rock.