Concrete's internal beauty shows through with an Exposed Aggregate Concrete Finish.
Exposed Aggregate Concrete is a commonly used method of creating a designer, decorative and classic finish around a pool deck, on driveways, patios and walkways.
There are a few different ways of creating an exposed aggregate finish in concrete. The 3 most common ways are:
Seeding your preferred aggregate into the surface of the concrete.
The monolithic technique where the aggregate chosen to be exposed is mixed into the batch of concrete
The topping slab method where a topping slab of concrete is used to create an exposed aggregate finish.
This is a simpkle how to and the prefered method of producing the common exposed aggregate concrete finish.
The 1st thing to do is to place the concrete with the chosen aggregate or pebble stone mixed in, Then you go about finishing the concrete slab as you would any concrete slab.
After placing and finishing the concrete slab and while it is still wet, the surface is sprayed with a concrete retarder. Retarder's are designed to slow or stop the curing process of the concrete to which they are applied. The retarder is sprayed consistently across the entire surface of the concrete slab. Only the areas sprayed with the retarder will keep from setting up and the cement paste around the aggregate looking to be exposed, will remains soft.
For The 3rd step is to clean off the uncured cement paste from around the aggregate, exposing the stone but not cleaning and scrubbing it hard enough to pop out the stone pebble or aggregate from the hardened concrete slab below.
As an added step and for additional protection, it is often recommended that you seal the newly finished exposed aggregate concrete to protected from staining and in helping the curing process for the concrete slab below to help prevent cracks and shrinkage.