Introduction
Spayed concrete is the term used for the high pressure spraying of concrete or mortar onto existing surfaces. It is extremely versatile as it can be sprayed over any shape or profile and in vertical as well as overhead situations.
There are two methods, the dry mix method referred to as Shotcrete and the wet mix method known generally as Gunnite.
Because the material is pneumatically forced through the nozzle at high pressure when the concrete hits the surface it is both placed and compacted.
For strengthening works, new reinforcement anchor bars are fitted and steel mesh sections wire tied or welded into position. The steel gives the structure the additional reinforcement but also give the sprayed material something to grip and adhere to.