The injection system creates a reactive aerosol that is injected centrally into the continuous flow of dry gunning mix material. A liquid binder can be added to the pre-wetted dry material via a conventional nozzle system at the end of the deliver hose.
Pre-wetting of the dry gunning mix offers several advantages, such as reduced dust generation at the gunning nozzle, less material rebound – particularly during overhead work – plus enhanced bonding to refractory surfaces.
Moreover, the concrete's cold crushing strength and cold modulus of rupture are increased, porosity is reduced, and a denser concrete structure is obtained.
The process has been optimized for cement-free shotcretes of the REFRAJET® Nanobond type, but it can also be used for many other concretes from Refratechnik's product range.