Innovation centre Kamp C took just three weeks to print the envelope for a two storey house using Cobod’s giant 3D printer
Belgium’s reputation for delicious chocolate could soon be surpassed by its expertise in another gooey substance of the less palatable variety – 3D printed concrete.
In what’s thought to be a world first, the construction innovation centre Kamp C used a giant on-site printer to spit out the structure for an entire two-storey home in one monolithic chunk.
Created at the firm’s facility in Westerlo, the 90m2 building features walls three times stronger than conventional brick, which were extruded in layers using Europe’s largest fixed 3D printer, the prototype BOD2 made by Denmark’s Cobod.
The house was built as part of Antwerp province’s C3PO project (Co-creation: 3D printing with companies), established to promote innovation in 3D printing, using finance from the European Regional Development Fund.
It is the absence of any prefabrication that makes the project so innovative, says Marijke Aerts, project manager at Kamp C: ‘Most printers prefabricate parts ready for assembly on-site. Ours was positioned on the site and printed the entire building envelope in one piece, including the foundations.’
BOD2 operates in a similar fashion to office-style plastic 3D printers: a gantry supports an extrusion head that’s able to move in three different directions with a print range of 10m by 10m by 10m. A concrete pump pushes custom made mortar through hoses to the extrusion head.
‘Layer time’ – the time it took the printer to extrude one layer of concrete over the entire circumference of the house – was about eight minutes, and the entire envelope was completed in around three weeks.
The technology reduced the need for wire-mesh reinforcement and eliminated formwork. The concrete mix contains metal fibres that prevent shrinkage and the risk of cracking during curing.
To avoid thermal bridges, some walls in the structure are designed with hollow interiors into which insulation was blown, while others had thermal insulation applied to the outside. Although the machine is capable of printing floor slabs, prefabricated slabs were used on this occasion.
M&E services were not installed during printing, but this would be possible, says Aerts, if the printer was instructed to include the necessary spaces in walls.
According to Kamp C, the project saved an estimated 60% on material, time, and budget, compared to traditional construction, and with further refinements an entire house could be printed in just under two days.
‘This technology is ready to scale up, we hope that our project can contribute to the commercialisation of 3D concrete printing on site,’ Aerts concludes.