Exposed Aggregate Concrete Construction
Exposed aggregate is a concrete finishing technique used to reveal the constituent stone or gravel in the concrete. It can be used on vertical and horizontal surfaces, but it is especially common on flatwork (see Architectural for options on vertical & structural). Exposing the aggregate offers a clean, elegant look with design options such as type of stone, shape, and colour of the background concrete. It can be used almost anywhere concrete is used. CementWright can provide well designed and executed exposed aggregate concrete that will last.
Layout, prep and forming
Key to any concrete project lasting is prep; this is if anything more important with exposed aggregate because of the visual attention it receives. An overlooked part of prep is the layout and forming of the concrete. Done well, this sets off an exposed aggregate slab and gives it a quiet elegance, but if this is missed, the slab will never feel quite right. Our reusable modular forming system for flatwork allows us more flexibility with curves and other design elements. We have good artistic sense and are careful to provide the concrete forming the attention it deserves.
Exposing the concrete aggregate
Exposing the gravel in the concrete is usually done with water while the concrete is still curing, though wet or dry sandblasting can also be used on cured concrete. Water is exposure is most common, as it uses the least equipment and doesn’t abrade the aggregate. To do a water exposure, the concrete is placed and allowed to set a certain amount, and then the top “cream” layer of cement paste and sand is scrubbed off with water and a broom. A non-toxic surface retarder keeps the top layer plastic while the remainder cures, which allows an even, well controlled exposure. Exposing the aggregate can be done using homemade sugar water or even no retarder, but these methods can be unreliable. Placing the concrete for an aggregate exposure requires experience and care. Any careless tool marks or footprints will push the aggregate down into the slab and leave a mark once the concrete is washed.
Care of exposed concrete
We provide cleanup of the slab and a coat of high gloss decorative sealer to protect the concrete and keep it looking new. Regular maintenance is important to all concrete’s longevity, but is especially necessary for decorative concrete. We can offer regular maintenance packages which include extended warranty if your time is limited; if you need help knowing what to do so you can do most of it yourself, we’ll help with that too.
CementWright’s artistic design and technical skill with concrete allows us to create beautiful exposed aggregate sidewalks, driveways and patios. We can provide the entire project, or just portions, as required. Our specialty is well designed and executed concrete. Contact us to start and we’ll work with you to come up with ideas for your project.