Exposed aggregate decorative concrete is an alternative to the plain smooth textured concrete that has commonly been used for driveways throughout Australia. Decorative exposed aggregate concrete is a way of dressing up your driveway, giving it texture, colour variation and life.
Decorative concrete uses a mixture of natural stone and rock that is crushed into varying sized pebbles that get mixed with other stone variations to achieve a desired colour combination and size spread. For example the mixture of light and dark stones with an array of shades between, mixed together to achieve a custom shade as defined by you. The exposed aggregate mix used within the concrete to achieve a decorative finish is highly customizable and gives you the opportunity to mix your own colour variations and have it matched by the supplier for a unique finish. From earthy reds to your light quartz colours and bluestone finishes, they can all be done separately or mixed at varying quantities, different sizes and at varying levels of exposure.
The colour of the concrete that provides the base layer for the aggregate finish can also be varied and chosen specifically to order too. The use of a light concrete with dark aggregate or dark concrete with light aggregate allows for many different finishes. Matching the concrete colour to the aggregate colour increases the subtlety of the textured surface whilst a contrasting base colour really makes the aggregate stand out.
The stones that are used within the aggregate are referred to as pebbles, these are usually sized from 3 - 6 millimeters however larger pebbles ranging up to 10 millimeters and beyond are mixed with the smaller aggregate to create variation within the spread of pebbles for added effect. The size of the aggregate used within the decorative concrete finish is dictated by the function of the area being covered. If the area is a driveway that is likely to be used by barefoot traffic or high heel shoes then the aggregate needs to be more refined to ensure it is not too textured causing it to be painful at touch or difficult to negotiate. Coarser finishes can be used to allow for increased water dispersion or drainage to prevent the surface from becoming slippery and dangerous.
The surface texture of the exposed aggregate heavily impacts the skid and slip resistance of the finished surface. This is a factor that needs to be considered heavily and a question you should be asking the provider of the mixture. Quickly telling them the purpose of the area being covered, its main use and what kind of traffic it will most likely see. This will allow them to sell you the sufficient grade of aggregate can be and will ensure you are happy with the finish.
Exposed aggregate decorative driveways are very durable and if chosen and installed properly they will be very resistant to abrasion. The pebbles within the decorative aggregate finish will not lift and the original finish can be maintained for years. In all a decorative exposed aggregate concrete driveway can add aesthetic quality to any driveway.
Mike Baxter, Epping VIC