What best describes "aggregate base" in construction?

Aggregate base is best described as a layer made of crushed stone or gravel that provides structural support under pavements. This material is crucial in construction because it helps distribute load and provides a stable foundation for the pavement layers above. The properties of the aggregate, including size, shape, and material type, contribute to the strength and durability of the pavement structure.

In the context of other choices, the option describing soft soil would not provide the necessary support needed for pavements, making it unsuitable as a foundational material. A decorative layer on road surfaces does not align with the functional requirements of an aggregate base, as it typically emphasizes aesthetics rather than structural integrity. Lastly, while landscaping material serves its own purpose, it does not play a role in pavement support, further illustrating why the correct identification of aggregate base is essential for understanding pavement construction.