Apparatus for wet spraying of concrete

An apparatus for the wet spraying of concrete, comprising a mixer embodying a mixing container incorporating means for closing such in a gastight fashion, a compressed air source connected with the mixing container, said mixing container incorporating a closable concrete outlet opening defined by a connection pipe, a substantially cylindrical concrete containing conduit of substantially constant diameter detachably introduced at one inner end through the connection pipe and in a position substantially flush with the inner wall of the mixing container, and a number of supplementary air infeed conduits located near the mixer and opening into the concrete containing conduit at locations spaced circumferentially about the periphery thereof for the infeed therein of compressed air to suppress the formation of concrete slugs, the infed compressed air flowing towards the central lengthwise extending axis of the concrete containing conduit to break-up any possibly formed concrete slugs.