Additive construction

Additive construction is the application of additive manufacturing to buildings and building components, forming them layer by layer from a digital model instead of casting them in formwork.

Updated

Additive construction is the application of additive manufacturing to buildings and building components, in which material is deposited layer by layer under numerical control instead of being cast into formwork. The term covers several process families: extrusion of cementitious mortar or earth, shotcrete-based printing, binder jetting of granular beds, and robotic placement of discrete elements. ISO/ASTM 52900 provides the general additive manufacturing vocabulary that construction work usually borrows from.

In practice

Most built demonstrations to date use material extrusion, because the equipment is comparatively simple and the mortars are close to conventional mixes. The geometry comes from a digital model that is sliced into layers and converted into machine instructions, so the printer never reproduces anything the slicer did not resolve. Additive construction is not a single standardised method, and design codes such as Eurocode 2 do not yet cover printed elements directly, so structural work is normally justified case by case with testing. Printed walls are also anisotropic: strength across the layer interfaces is generally lower than within a layer, which has to be accounted for in design.

Related terms

  • Digital fabrication — the wider field of machine-driven production from digital models.
  • Formwork-free construction — building without moulds, the main geometric argument for additive construction.
  • 3D concrete printing — the cement-based branch of additive construction.

Related

3D Concrete Printing3D concrete printing builds elements layer by layer without formwork. How extrusion, particle-bed and shotcrete methods work, and where the limits are.ExtrusionExtrusion is the process of forcing fresh mortar through a nozzle to form a continuous filament, the dominant deposition method in concrete printing.Formwork-free constructionFormwork-free construction is the shaping of concrete elements without moulds, with geometry produced directly by a printer or a similar process.Digital fabricationDigital fabrication is the production of physical elements directly from digital models by computer-controlled machines, with no manually made moulds.