Beneficiated Concrete Finishes
New in South Africa and exclusive to Bosun. Bosun offers concrete pavers with various beneficiated finishes or surface textures, which are new in South Africa and exclusive to Bosun. These finishes are achieved by means of technical processes with specialised machinery and equipment as shown below in these highly simplified graphic representations.
Ground Pavers
The Grinding of concrete involves cutting the surface or “face” of the concrete with a series of diamond tipped blades creating a fairly smooth texture. The smoothness of the surface texture is dependent on the use and application of the amount of cutting blades being used.
The desired outcome of this process is to expose stones with interesting natural colours on the surface of the pavers.
The difference between Grinding and Washed and Shot Blast is that stones on the surface of Ground pavers are perfectly flat and smooth whereas stones exposed by means of Washing or Shot Blasting will still have a naturally rounded shape.
Grinding is an expensive process due to blade costs.
Shot Blast Pavers
The Shot Blasting process involves peppering pavers or kerbs with “Shot” or small beads of steel which are fired at high velocity by means of compressed air. The Shot actually dents the surface of the product bit by bit thereby dislodging small particles of concrete which then fall away. This exposes small stones and other aggregates in the topping.
In a sense the result is similar to that of washed pavers as described opposite but a Shot Blast texture is slightly smoother although more irregular than a Washed texture.
Washed or Exposed Aggregate Pavers
In the washing process fine cement particles are removed from the paver’s surface with a special water spraying technique which exposes beautiful small stones in various colour schemes, creating interesting and hard-wearing surface textures.
Chamfered Pavers
Chamfering is a process where an angled edge is cut on the paver. This could be done on any one, or all of the edges.
Calibrated Pavers
Calibration is a process whereby the bottom of a paver is cut with a diamond tipped blade in order to create a thickness which is dimensionally accurate and consistent.
It is almost impossible to manufacture large pavers and maintain accurate and consistent heights. The SANS height variance specification on large pavers is ±5mm. This could result in a 10mm variance between two adjacent pavers which are however still within the specified range.
All large paving stones should be calibrated prior to resale.