In the outdoor space at Driebergen-Zeist, several elements in the factory were made with our concrete printer. In addition to four kidney-shaped tree planters, ranging from 30 to 80 meters long, the retaining wall of an outflow basin was also made with a 3D printer.

Because the station square is very low, runoff and rainwater are collected in an underground basin with overflow. Once the basin is full, the water is pumped through the outflow basin into a nearby ditch, keeping the water in the area. The retaining wall has a curved shape, and due to its soil-retaining function, the thickness decreases from approximately 1.20 meters at the base to approximately 0.50 meters at the top.

Stefan Bloemberg, a BAM supervisor, said: “Such an element is almost impossible to do with formwork. So, here again, the 3D printer offered a solution. The cost of the printed lost formwork was equal to that of the budgeted traditional formwork. However, the great advantage was the significant savings in labor and lead time.”