Exposing Concrete Aggregates
Aggregates serve a twofold purpose in concrete, they make it stronger and they can make it decorative. Let’s leave the science of concrete strength to the contractors and take a look at how aggregates beautify concrete.
All concrete has some kind of aggregate in it. Would you believe that under that solid surface their could be an array of aggregates of varying shapes and sizes? Sometimes contractors expose this aggregate by grinding or polishing the concrete’s surface. This type of concrete finish is called an exposed concrete aggregate.
Aggregate Materials
This sink top by Ornamental Concrete incorporates a white vein with a red glass aggregate.
There are several different kinds of aggregate that can be used for decorative purposes. The most popular being various stone or glass material. When requesting specific materials to act as an aggregate in the concrete you may receive an answer that the material cannot or should not be used. It is probably because the material, is too soft and could lose its shape or color in the mix, has chemical components that would react with the concrete, or is quite expensive to prepare for use in the concrete. There are still many suitable options that can achieve an asthetic you desire.
Aggregate Applications
There are two ways of applying aggregates. It can be mixed into the concrete prior to pouring, this is called batching. This allows for an even spread of the aggregate in the finished product. Batching aggregate is usually used for large surfaces such as driveways and pool decks. It provides a surface that is rugged, nonskid, and resistant to heavy traffic and weather extremes.
This beautiful aggregate drive was created by IConcrete WA, Exposed and Honed Aggregate Specialists.
The Concrete Countertop Institute demonstrates seeding a form with glass aggregate. Remember the bottom of the form will actually be the top of the concrete surface.
Another method is called seeding and is used for more decorative purposes with smaller surfaces such as concrete countertops. Seeding involves laying the aggregate onto the surface of a form prior to pouring concrete. It can be placed in specific designs or specific areas of the product. Seeding also allows for more expensive aggregates to be used since lesser amounts are necessary.
Aggregate Designs
The fun thing about aggregates is that other concrete applications can be incorporated alongside them. Sections of exposed aggregate can be interlaced with stamped concrete borders or you can have multiple levels of grinding and polishing to add variation. Different aggregates can be mixed together or flow into one another in the products for unique designs. The concrete can be colored so you’re not just dealing with a gray finish.
Concrete Decor says that when staining an exposed aggregate floor, the aggregate color remains the same because the stain only affects the concrete matrix.
Stamped Artistry put together this gorgeous white counter space with a colored glass/stone aggregate.
Even if you choose not to expose the aggregate, it is still an essential part of concrete and a good thing to keep in mind when considering your options.