Exposed Aggregate Concrete
The most commonly know method of exposed aggregate is done by washing away the surface of the freshly poured concrete to expose the pea gravel in the mix. This method uses the native aggregate to the local concrete redi-mix plant. Normally the aggregate used is pea gravel and about 3/8” in diameter. The concrete company delivers a specially designed, exposed aggregate mix which is poured and finished. After the concrete has taken it’s initial set a special retardant is applied to etch away the surface of the concrete, After the retardant has done it’s job the surface is then carefully washed away to expose the aggregate of the mix. This method of exposing aggregate is limited to the aggregate used by the concrete company nearest your project.
More expensive special colored and uniformly sized aggregates can also be used. These finishes are unique and use aggregates that can be imported from anywhere in the world. These special aggregates are the cast uniformly over the surface of the fresh concrete and require much more attention from the installer. The aggregate is very carefully worked into the surface to ensure a uniform coverage of surface. At the proper time a special retardant is sprayed over the surface then later washed away. This method is known as “hand seeded aggregate”.
These types of finishes are unique in nature and require much more training to be properly installed. There are many beautifully colored, river tumbled aggregates to choose from and sizes vary from 1/8’ in diameter to 1”. The beauty of these natural aggregates in landscape design is unsurpassed and offers a very hard long lasting surface for any project.