PROCESS FOR PICKLING OR DESCALING A CONCRETE SURFACE

摘要

A process for pickling or descaling a concrete surface via the use of at leat one jet of liquid nitrogen at a cryogenic temperature of less than -100°C at a pressure of at least 500 bar, distributed via the outlet orifice (2) of at least one nozzle (1) for distributing a jet of liquid nitrogen. At least one part of the distribution nozzle (1) is protected by a resistant material having a hardness of at least 7 Mohs. Preferably, the resistant material is deposited externally onto at least one part of the wall (3) of the nozzle (1). Advantageously, the material is chosen from tungsten carbide, boron carbide, titanium carbide, silicon carbide, cubic boron nitride, alumina and corundum.