What is it?
Aggregate is a mixture of stones, pebbles, small rocks, etc. added to concrete to increase its strength. Exposed aggregate is a method of allowing one to see these aggregates or exposing them to view. This is used more and more in decorative concrete to some fantastic results.
Some of the Exposed Aggregate used are basalts, granite, quartz, or limestone in all sorts of natural colours. You can use this decorative aggregate anyplace you would use plain concrete--driveways, entrances, steps, paths, patios, to name a few.
There are a few different methods that are used to expose the aggregate. These are:
MONOLITHIC: The aggregates are mixed into the concrete at the start and just poured.
SEEDED: Seeding is when you place or "seed" the aggregate on the surface of the concrete after it is poured. It is then floated (smoothed out) by hand.
OVERLAY: Overlaying is used to give an older concrete installation which is in pretty good shape a face-lift. The aggregate is mixed into a topcoat material and applied to the existing concrete.