Exposed concrete

When an even non-slip surface is desired, exposed aggregate concrete is one of your best choices. The great advantage of concrete is that you can shape it to your personal specific needs. It is probably the most versatile and affordable paving material available.

An exposed-aggregate surface is obtained by placing concrete and then stripping away the plain, boring cement surface to reveal the natural beauty of the coarse aggregate lying beneath. (The coarse aggregate is either batched into the concrete mix or applied onto the surface). Exposed aggregate concrete is suitable for sidewalks, driveways, patios, paths, plazas and pool surrounds, because of its durability and non-slip surface. RG Paving in Hermanus are professionals who will do an excellent exposed aggregate concrete paving job for you.

An exposed aggregate finish has many advantages. It combines the durability, strength and affordability of concrete with the natural decorative beauty of aggregates. A great variety of different looks and textures can be created by using pebbles and crushed stones of different colours and sizes. You can achieve impressive results even without expensive aggregates.

Sometimes it is the only type of paving that can be used on very steep slopes (Normal brick pavers might “pop up” or give way if the materials in the sub base of a steep slope get water soaked, causing it to lose its shear strength. You can still use brick paving if the pavers are laid on a solid concrete base). 

It can be used in tricky situations where unusual or sharp curves are required (Curves that are too sharp don’t work so well with square paving bricks, because the corners may stick out). It has the added advantage that ducts for services can be cast into it. Exposed aggregate concrete will also give a very neat finish around any objects that protrude through it (like services, columns and lamp poles). 

There are some cons of concrete slabs that you should be aware of when choosing between pavers or a slab: Pavers can handle four times as much weight on them before they would crack. Concrete slabs are not as easy to repair as segmental paving. If you repair a patch it will never look exactly the same as the existing slab.

Another type of exposed aggregate concrete is permeable concrete, also known as “no fines concrete”. It is concrete made only with coarse aggregate, and no sand. (It must be laid on a bedding layer of crushed stone, in order to prevent any runoff cement slush from sealing the underside of the slab). It is completely permeable. Colours are limited to the colours of oxide that is added to the concrete mix. (The cement layer covering the coarse aggregate unfortunately cannot be stripped away from the top, because it will weaken the adhesion of the aggregate to the slab). 

This can be used around trees (those with no roots protruding the surface), because water can still reach the roots through the permeable paving. (If a tree has a shallow root system, then loose crushed stone, similar or contrasting to the exposed aggregate paving, can be placed around it and levelled).  

Cons of permeable paving: Sediment can clog the paving, and it can be difficult to remove. It is not as strong as normal exposed aggregate concrete, and therefore not recommended for vehicular traffic.