In-situ printing

In-situ printing is 3D concrete printing carried out on the construction site itself, so that walls and other elements are built directly in their final position instead of being produced elsewhere and transported.

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In-situ printing is 3D concrete printing carried out on the construction site itself, so that walls and other elements are built directly in their final position instead of being produced elsewhere and transported. It removes the size limits imposed by road transport and lifting equipment, and it eliminates the joints that a precast solution would need between elements.

In practice

The trade is variability. A printable mortar has a narrow rheological window, and that window shifts with ambient temperature, wind, direct sun and humidity, all of which are uncontrolled outdoors. Printing usually stops in rain, in frost and in strong wind. The site also has to supply a level, load-bearing base for the machine, stable power, water, and a materials route that keeps the pump fed without interruption. Setting up and calibrating the printer is a distinct phase of the works, and on a small building it can take a meaningful share of the total time on site.

Related terms

  • Precast — the alternative approach, where elements are made in a controlled shop.
  • Gantry printer — the machine family most often used for on-site work.
  • Open time — the workable period of the mix, which shortens in hot weather on site.

Related

Precast concretePrecast elements are produced away from their final position and transported to site, which is how most 3D-printed concrete parts are delivered.Gantry printerA gantry printer is a construction 3D printer whose print head moves on a rigid frame of linear axes spanning the build area below it.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.3D Printed Wall SectionsPrinted concrete walls: single and double skin, cavities and insulation, partitions, garden and retaining walls, and the reinforcement questions.