In South Africa, almost all newly-constructed highways and arterial roads are surfaced with asphalt, or tar, as it's locally known. These roads are built to handle high traffic volumes and heavy loads. Kotze Construction specialises in all forms of road construction that are needed for South Africa's climate.
The type of surface material used in road construction is largely dependent on traffic volume, weight load and weather conditions. As extreme temperatures are not a factor in South Arica, the roads network features three types of road construction surfaces, with a fourth only sporadically used.
Gravel
Gravel is a practical, affordable, low maintenance surface for rural roads that have a low traffic volume, particularly of load-bearing trucks. Gravel can be brought in and applied to a freshly cut road and compacted, or the existing surface is graded to create a crown, sloped shoulders and run-off ditches.
Drains are typically added at intervals to remove rainwater, to preserve the integrity of the road.
Bituminous seals and slurries
Bituminous seals and slurries are effective surface solutions for low traffic roads with minimal weight loads. A bitumen rubber chip emulsion is sprayed onto pre-compacted aggregate and rolled into the base layer to create a hardy, sealed road surface.
It's a durable and comparatively inexpensive solution for secondary roads and is widely used in villages, towns and suburban areas of the cities.
Asphalt
In South Africa, almost all newly-constructed highways and arterial roads are surfaced with asphalt, or tar, as it's locally known. These roads are built to handle high traffic volumes and heavy loads.
They consist of several base layers of aggregate that are compacted and stabilised before a final layer of tar is laid over the surface. The application method and temperature can range from cold mix to hot mix and is dependent on the average traffic load.
Hot-mix consists of free-floating screed and is the surface of choice for highways with high traffic volumes. Conversely, Cold-mix is predominantly used on quiet secondary roads.
Concrete
Concrete road surfaces are composed of cement and other materials, such as aggregate, fly ash and chemical admixtures. The concrete is laid on a prepared surface in jointed blocks, or in a continuous layer reinforced by mesh or steel.