3D printing with concrete in architecture becomes more and more popular. We have seen examples of a bridge and even entire houses (here and here). The French company XtreeE used the technique to make a truss-style supporting column for a preschool playground in Aix-en-Provence. Instead of 3D printing the column itself, the company 3D printed a hollow formwork, or outer layer, for the complex concrete column, which was then filled with concrete.

After the final geometry of the outer structure was designed by topological optimisation, it was divided into four parts for fabrication. The company used a special mixture of concrete to form the envelope, which took 15-and-a-half hours to print.

When the formwork was done, it was filled with LafargeHolcim concrete, creating a solid instead of a hollow column. After the concrete had set, the formwork was removed and the remaining structure of the complex concrete column was assembled. The 4 metre (13 feet) high column was placed on site, filed to remove the appearance of each printed layer, creating a smooth surface. Thanks to the filing, the seams are nearly invisible.

The result reminds a little of a fabric formwork column, also made from concrete, made by a group of students from the Technical University Eindhoven (NL).

The project for the building was designed by Marc Dalibard, but XtreeE executed the final design and the production of the concrete column.

Photos: Lisa Riciotti / XtreeE (via Archdaily)