Aggregates are materials used in construction and civil engineering, primarily consisting of sand, gravel, crushed stone, and recycled concrete. They serve as a key component in concrete and asphalt, providing strength and stability to structures like roads, bridges, and buildings. The properties of aggregates, such as size, shape, and texture, can significantly affect the performance of the final product. For example, concrete made with well-graded aggregates tends to have better workability and durability. Proper selection and testing of aggregates are essential to ensure the quality and longevity of construction projects.