Guncrete
Building Construction in Johannesburg

Founded in 1934, guncrete is today South Africa's most experienced sprayed concrete specialist. guncrete is a member of the International Sprayed Concrete Association in the U.K. Specialising in sprayed concrete repair for almost any application, guncrete has an enviable record established over more than half a century of successfully completed projects.

The technology of sprayed concrete has long been used in the maintenance and repair of buildings and structures of all types. Developed in 1895 by Dr Carlton Akeley, the technology of concrete spraying has evolved continuously over the ensuing hundred years. Today, it is regarded as the optimum solution for a wide range of repair and maintenance applications. The application of sprayed concrete is not restricted by shuttering of formwork, which makes it possible to apply a protective layer of concrete to almost any shape, or surface, regardless of location and orientation. The use of sprayed concrete in the mining sector has evolved from underground tunnel support to other fields such as lateral support and rock-stabilisation to surface declines and box cuts, as well as erosion protection to earth embankments. Further use of sprayed concrete is being utilised in the lining and protection of existing concrete structures such as Ore Silos and Tippler Bins, in some cases for the rehabilitation of these structures in order to extend their mine life at a relatively low cost compared with that of replacement, not to mention the reduced downtime of the mine's production is another benefit. We have also expanded our expertise to provide more intricate types of support to suit all mining conditions, such as rockbolting, meshing and lacing. From a company perspective, at guncrete we believe that every repair project is different and should be handled individually. Liaison, planning, design, preparation and application play equally vital roles, alongside the provision of a one-stop service to industrial users and engineers alike. By using skills acquired over decades alongside the most advanced sprayed concreted technologies, a guncrete project is started sooner and finished earlier; saving both time and money. When repair work is required, almost all maintenance projects can be undertaken using sprayed concrete. Specific application data and technical guidance is available to guncrete clients on request. Sprayed concrete is a dense, small-aggregate concrete pneumatically projected at high velocity against a surface. The force of the impact compacts the concrete to such an extent that for most applications the material has zero slump. As a result, sprayed concrete significantly outperforms traditional concrete in terms of both strength and durability. A mixture of cement and aggregate is combined with a measured amount of water, sufficient to hydrate the mix. The strength of sprayed concrete will depend on application specifics, but is generally applied in a range between 30 Mpa and 50 Mpa; adequate for all but the most complex and challenging of maintenance projects. In normal applications, sprayed concrete is based on ordinary portland cement, which is able to withstand the rigours of most industrial repairs. For situations where heat, corrosion, impact and rapid repairs are a prime consideration, calcium aluminate cement is preferred, for both longevity and effectiveness. These benefits contribute in no small way to making sprayed concrete a superior maintenance solution.