What Is Exposed Aggregate?

Despite being around for decades, exposed aggregate remains an incredibly popular concrete finish. Drive through the average Aussie suburb and you’ll likely come across exposed aggregate driveways, pathways, outdoor entertainment areas and pool surrounds. This isn’t surprising considering how versatile, hard-wearing and low maintenance exposed aggregate is, even when exposed to harsh or variable climates.

But what is exposed aggregate? How is this concrete finish achieved? Are there different types of exposed aggregate available? And just how durable is exposed aggregate?

What is aggregate in concrete?

Aggregate is the name for a large number of gravel-like crushed stone materials used in construction. But the exposed aggregate in concrete is often coarser and more decorative than your average construction aggregate. To create an exposed aggregate finish, the stone is either mixed into the concrete or applied in a thin layer over the surface of the concrete slab. The top layer of cement is then removed, leaving behind the decorative exposed aggregate. Creating an exposed aggregate finish can be likened to polishing a gemstone – the dull outer layers are stripped back and the decorative interior is polished into a brilliant finish.  

Are There Different Types of Exposed Aggregate Available?

There is a lot of variety when it comes to exposed aggregate finishes for concrete. Not only can you choose from a selection of colours for both the aggregate and the concrete, but there are also variations in the size, density and even the type of aggregate used. Naturally sourced aggregate can originate in riverbeds, construction sites, quarries and even off the seafloor, which is why there is such an impressive range of exposed aggregate to choose from. This makes it easier to find an exposed aggregate to suit a wide range of tastes and budgets.

How Durable is Exposed Aggregate in Concrete?

Exposed aggregate in concrete is an exceptionally durable finish, capable of lasting over 40 years without cracking. This is one of the reasons for its enduring popularity in Australia, particularly for use in areas that are highly visible and that receive a lot of traffic (such as footpaths, alfresco areas and driveways). Not only is exposed aggregate in concrete more durable than many natural stone surfaces, but it can also survive well in the many extreme weather conditions experienced throughout Australia. 

What are the Benefits of Exposed Aggregate in Concrete?

In addition to looking fantastic and wearing well, exposed aggregate is also:

• A low maintenance finish: Exposed aggregate requires minimal maintenance, generally needing little more than the occasional sweep. Routine pressure washing will help to keep the exposed aggregate clean from contaminants, while the occasional resealing will protect the surface from staining.
• Simple to install: Exposed aggregate may look ornate, but it is actually quite simple for experienced concreters to install a driveway, path or patio with an exposed aggregate finish. This makes it a more affordable finish than many people may think.
• Slip-resistant: Unlike plain concrete or many stone pavers, the irregular finish of exposed aggregate provides excellent grip. This means that an exposed aggregate finish remains slip-resistant, even in wet weather or on steep gradients.

To find out more about exposed aggregate in concrete, or to obtain a free quote, contact the friendly professionals at Seamless Concrete.