shotcrete

thumb|Early cement gun, Sydney 1914 thumb|A building worker spraying shotcrete on welded wire mesh thumb|Shotcrete nozzle with 75 Millimetre|mm concrete hose from line pump and 20 mm [[compressed air line]] thumb|Shotcrete swimming pool under construction in [[Northern Australia]] thumb|A 76 mm borehole in fibre-reinforced shotcrete on a tunnel wall thumb|A shotcrete curvelinear wall at the Museum of the History of Polish Jews in [[Warsaw, Poland]] right|thumb|Shotcrete-stabilized cliff above a [[motorway in New Zealand]] Shotcrete, gunite (), or sprayed concrete is concrete or mortar conveyed through a hose and pneumatically projected at high velocity onto a surface. This construction technique was invented by Carl Akeley and first used in 1907. The concrete is typically reinforced by conventional steel rods, steel mesh, or fibers.

The concrete or mortar is formulated to be sticky and resist flowing when at rest to allow use on walls and ceilings, but exhibit sufficient shear thinning to be easily plumbable through hoses.