3.3.10 Cape Seal
Cape seals were developed and first used in the Cape Province of South Africa. They are constructed by applying a single/single seal to the pavement (usually using a size 14 or 20 mm aggregate) followed by a slurry (or microsurfacing) that can either partially fill the void space between the bitumen and the top of the aggregate (Figure 3.13), or completely cover the top of the aggregate. This is achieved by either a single or double application of slurry.
This type of treatment provides a very robust surfacing and the surface characteristics are substantially those of slurry. It has been used in rural areas to provide a surfacing with high shear resistance, comparable to that of asphalt, but in areas where asphalt is not economically viable.