How do coarse aggregates differ from fine aggregates?

Coarse aggregates are defined as those materials that have a particle size larger than 4.75 mm. This classification is crucial in construction and materials engineering, as it significantly affects the strength, durability, and overall performance of concrete and other composite materials. Coarse aggregates, which typically include gravel and crushed stone, provide bulk and structural framework for concrete, while also facilitating drainage and reducing the amount of cement required.

In contrast, fine aggregates, which consist of particles smaller than 4.75 mm—such as sand—play a different role in the concrete mix. They help fill the voids between coarse aggregates, enhance workability, and contribute to a smoother surface finish.

Understanding this size distinction is foundational for engineers and inspectors, as it informs decisions on material selection based on the requirements of specific construction projects.