Additive manufacturing of cantilever - From masonry to concrete 3D printing.

3d printing of cementitious material is a relatively new additive manufacturing process whose growing interest and fast development is mainly due to the digitalised manufacturing, allowing the disposition of material where it pleases. Yet, due to the properties of the fresh material and the difficulty to generate paths for the robots, the printed geometries have remained simple. In this regard, this papers longs to broaden the range of printable shapes by proposing a process-aware exploration of the 3d printing design space. This is done by looking at historic strategies that have been developed to build cantilevers, vaults and domes in masonry - a more ancient additive manufacturing process. Similarities and main differences between the two processes are pointed out, at the scale of the component, the layer and the global structure. From that a classification of masonry strategies to build cantilevers is proposed, facilitating the identification of parameters for 3d printing that will allow to reproduce such structures. Later, some guidelines for the design of printable geometries and the generation of robotic toolpaths are given, in the light of previous findings. • Stability during 3d printing must be verified at the scale of the lace section, the layer and the global structure • Cantilevers in additive manufacturing can be done by creating local corbels or by inclining the layers • For a similar global cantilever, inclining layers will create less stress in the material than a local corbel • A structure printability depends on the material used but also on the printing set-up - pump capacity and the maximum speed of the robot. [ABSTRACT FROM AUTHOR]