All concrete aggregates work in similar ways. These mixes combine concrete and other materials, such as stones, glass, or gravel, to create surfaces with extra features. For example, you could use a glass aggregate to create a decorative path or an exposed gravel mix to create a path with more traction.
If you want to use this kind of mix, then you don't just have to decide which aggregate to use. You also have to choose how the mix is put together. While you can mix the aggregate straight into your concrete, techniques such as topping sometimes work better.
How does topping work? Why should you consider using it?
What Is a Topping Aggregate?
A topped aggregate looks much the same as a fully-mixed product. However, you add the aggregate to the concrete in a different way.
If you use a fully-mixed technique, then your aggregate goes straight into the concrete when it is mixed. All of the concrete you lay on your surface contains some aggregate.
If you use a topping technique, then your aggregate doesn't run through the whole surface. It sits on the top layer. Here, your contractor puts down a base of pure concrete. This layer doesn't contain any aggregate. They then mix more concrete with your chosen aggregate material and pour this mix on top of the base layer.
The depth of your top layer depends on the size of the material you put in the mix. Tiny stones might only need a thin topping layer; larger pebbles will need a thicker layer.
Why Use a Topping Aggregate?
If you want to create a fast uniform effect or to add some grip to a surface, then a topping aggregate mix is a good solution. It is easier to control how an aggregate will lie if you pour it as a thinner layer of concrete. The underlying base also gives your topping layer a stable foundation.
Topping aggregates are also typically cheaper than full mixes. If you have to mix aggregate into all the concrete that you lay, then your material costs increase. You have to buy more aggregate.
If you top your concrete, then your costs reduce. You only need to buy enough materials to get coverage in the top layer of concrete. You don't need aggregate in lower layers. So, your project will be more cost-effective.
For more advice, contact your concrete aggregates supplier. They can help you build the right mix for your needs.