What does the term "coarse aggregate" refer to in concrete construction?

The term "coarse aggregate" in concrete construction specifically refers to aggregates that are retained on the 4.75 mm sieve. In the context of concrete, coarse aggregates typically include materials such as gravel, crushed stone, or recycled concrete. These aggregates provide strength and bulk to the concrete mixture, contributing to its overall durability and performance.

Coarse aggregates play a crucial role in the concrete mix design, as they affect the workability, strength, and shrinkage of the finished product. Understanding the distinction based on sieve size is vital for technicians and engineers to ensure proper grading and sizing are achieved for optimal results in concrete applications.

The other options describe characteristics that do not correctly define coarse aggregate. For example, aggregates that pass through the 4.75 mm sieve would be classified as fine aggregates, while aggregates smaller than sand particles would also fall within the fine aggregate category. Additionally, aggregates used solely for aesthetic purposes do not pertain to the structural role that coarse aggregates fulfill in concrete construction.