Oval staircases will link the floors at the SAB Bank HQ. The stair design was guided by a desire for lightness and openness. The steps smoothly emerge from a supporting wall, to create the impression that the staircase is floating.  The construction of the staircase was a technical challenge due to the complex shape and the curvature of the soffit. To replicate the geometry, Doka opted to 3d-printing the most complex part of the formwork on the basis of a detailed 3D CAD model developed and provided by ACME. Using Powder Binder Jetting Printers, the elements of the formwork were produced with a gauge of 21mm in thin layers of sand and resin. The precision printed formwork allowed assembly on the site within hours. This was the first time that 3d printing for formwork had been used at scale in a commercial project in Germany. Using this innovative process enabled the construction team to save time and to obtain a smooth and seamless concrete mould and showed ways how complex geometry can be delivered cost effectively on site.
Image credits: DOKA