When the outer skin of concrete surface is removed, an exposed aggregate concrete surface is visible. The action of removing the outer skin of the concrete surface is also referred as the decorative process of exposing aggregate. An exposed aggregate finish is most suitable for flat surfaces such as driveways, sidewalks and, pool decks. Exposed aggregate is widely used due to its numerous advantages. There are so many factors you need to consider when choosing aggregate, including hardness, size, durability, exposure method, cost and color. Exposed aggregates have a wide range color selection and are similar to polished granite or marbles.
Aggregate Concrete Exposure Methods
Once the surface has been covered with concrete paste, the aggregate can be exposed to make the surface more attractive and decorative. Exposure methods depend on the desired look and magnitude of the project. In every exposure method, only the top surface is exposed and the rest of the section stays embedded in the concrete. Below are the most common aggregate concrete exposure methods:
- Bushing and Washing: This is one of the easiest methods to create exposed aggregate concrete This method doesn’t require any unique equipment or chemical retarders. Here, you just need to wash the topmost layer of the surface using water. Wash and scrub the surface simultaneously until the aggregate is revealed. Continue washing and scrubbing till you reach the desired depth. In this method, the timing is highly important. You should start the aggregate exposing process as soon as the mortar is ready to be removed. Since you are manually handling the entire process, this method is ideal for a small area.
- Using a Surface Retarder: Unlike the brushing and washing method, contractors here spray a chemical retarder on the concrete surface. This makes the surface to retain flexibility for a day or two. So if you need exposed aggregate concrete on a large surface, you get enough time to complete the job.
- Abrasive Blasting: In this method, aggregate is exposed after concrete has been set and hardened. The only problem here is that aggregate might get dislodged and its appearance will be impacted. So this method is not ideal if you desire to maintain the shape and color intensity of the aggregate.
Benefits of Exposed Aggregate Concrete Surface
- Durable: One of the main benefits of exposed aggregate concrete is durability since aggregate concrete can last for more than four or five decades. It can tolerate heavy traffic and extreme weather conditions. It has a rugged surface, because of which it can easily handle harsh elements. Due to its durability, it is ideal for driveways and walkways.
- Decorative Look: Exposed aggregate concrete has a beautiful and attractive effect on its surroundings. It has a wide range of color, shape, texture, and design variations and you can customize aggregate installations according to your desire. Aggregate concrete need not only be black or grey, and you can choose from a wide variety of colors to make it visually more attractive and pleasing.
- Skid and Slip Resistance: Wet surfaces are prone to skids and slips. Sometimes, slipping may cause serious bodily injuries and fractures. So, to avoid such situations, exposed aggregate is a great option since a rough surface prevents skids and slips.
- Low Maintenance: Exposed aggregate concrete surface does not require any special maintenance and only requires occasional surface cleaning with water. If the surface still looks dull, then you can just reseal the surface to give it a glossy appearance. Usually, aggregate concrete requires resealing every 3 to 5 years.
All things considered, along with several benefits, aggregated surfaces contrast well with their surroundings. This makes it the most versatile and ideal option for exterior concrete.