Abstract: The present relates to an apparatus for manufacturing 3-dimensional concrete structures comprising a projection head (1) for spraying concrete material, wherein the projection head (1) comprises a projection nozzle (11) for spraying the concrete material and at least two guiding surfaces (12) provided on both sides of the projection nozzle (11) and defining a volume in between, such that the projection nozzle (11) is adapted to spray the concrete material into said volume, and wherein the projection head (1) is repeatedly moved along a predefined path by a control means and is configured to adjust the position of the two guiding surfaces (12) during the movement of the projection nozzle (11) so as to create a 3-dimensional concrete structure made of a plurality of projected concrete layers.