When you're having concrete installed at your home, you may want to go for exposed aggregate. An aggregate is made of rock, polished glass or another similar material and is added to the top layer of concrete. This gives it texture and makes the concrete more visually appealing. Note a few tips for choosing the right aggregate for a concrete surface.
Colour
One thing to remember about the colour of an aggregate is that it will look bolder and richer when it's spread out over a large surface, such as a driveway or walkway. Trying to determine the right aggregate colour by a small photo in a catalogue is like trying to determine the right wall colour from a small paint chip; it can be better to ask for photos of the aggregate on a large, finished surface so you can see how it looks when spread over a similar space.
It's also helpful to compare the colour of the aggregate to the colour of your home itself; bring photos of your home to an installer's showroom, or take a catalogue or brochure outside and hold it up against the home so you can more easily see how the colours compare when side by side.
Shape
Glass or pebbles will be rounded and smooth, whereas some gravel varieties come in a variety of bumpy shapes. The bumpier shapes can be good for controlling water runoff and will provide more traction on a driveway, but they may be uncomfortable underfoot. For a concrete surface around a pool or for a patio or walkway, choose the rounded and smooth glass or pebbles instead.
Note, too, that flat pieces of aggregate are more likely to come loose over time, as they are not as nestled into the concrete as other shapes. They may not be the best choice for driveways, as the pull of car tyres will increase the risk of them coming loose.
Source
Note from where the aggregate is sourced; local and easily harvested materials are often more affordable and will be easier to find when you need to replace any dislodged aggregate. Speciality glass and other such materials may mean higher replacement costs over time. Local materials that are easy to harvest also means less blasting and other damaging methods needed to harvest these materials, and fewer fumes and emissions created with transport and shipping. This makes them a more eco-friendly choice.