aggregate
![fine aggregate](../../images/fine_aggregate.jpg)
Fine aggregate (sand).
![coarse aggregate](../../images/coarse_aggregate.jpg)
Coarse aggregate (stone). Images: Sonag Ready Mix LLC.
Aggregate is a building material which is mixed with an adhesive such as cement to make concrete and mortar. Fine aggregate, usually sand or crushed stone, is used for smaller structural members where a smooth surface is required; coarse aggregate, such as pebbles or small angular stones, for larger members.