As stamped concrete has become increasingly popular, one older concrete technique has become less common — though it’s as beautiful and useful as ever. 

Exposed Aggregate Sidewalk Detail

While stained and stamped concrete are excellent options for many applications, exposed aggregate is a beautiful style with many benefits, both in design and function. 

Let’s take a look. 

What is exposed aggregate?

All concrete contains just three essential components: water, Portland cement and aggregate. The aggregate are the chunks of rock, sand or gravel that make up the bulk of the concrete, held together by the water/cement mixture. 

Exposed aggregate concrete requires removing the outer layer, or skin, of the concrete paste, revealing the aggregate beneath. This is done after the concrete is laid in place, usually by scrubbing or pressure washing. 

What are the benefits of exposed aggregate?

A stained patio with an exposed aggregate border.

Durability: One benefit of this technique is that it obviates spalling, which is the eventual flaking away of the surface of the concrete. 

“All concrete wears down over time to this type of finish due to erosion or high traffic,” concrete contractor Ryan Diehl said in an interview with Concrete Network. “Exposed aggregate is less likely to undergo this spalling effect because the cement paste is already removed, and done so in an even manner.”

Beauty: Evoking images of cobbled streets or old, weather-worn walkways, exposed aggregate has a timeless beauty. The style also can be combined with other concrete finishing techniques to create gorgeous patterns in driveways or walkways. Exposed aggregate can be combined with pervious concrete, for example, to create a stylish driveway that allows for water drainage.

Another common technique for patios and driveways is to use colored concrete bands amid fields of exposed aggregate. Exposed aggregate also works well for retaining walls and provides excellent slip resistance on stairs and inclined paths.  

Exposed Aggregate with pervious concrete insert built in patio drainage (r)
An exposed aggregate driveway with a pervious concrete ribbon for improved drainage.

Because the look of the exposed aggregate depends on the rocks or pebbles used in the mix, your options are almost endless, and the end results can be more natural looking than stamped or stained concrete. 

If you’re interested in the benefits of exposed aggregate concrete for your own project, give Custom Concrete Contracting a call. Our trained and experienced concrete flatwork finishers would love to help.