German companies Putzmeister and Züblin produced a warehouse with complete and supporting concrete walls from a 3D concrete printer for what they say is the first time.

Called STRABAG BMTI (STRABAG Baumaschinentechnik International), the warehouse was printed layer by layer using a mobile concrete printer, KARLOS. The building is made using new technology that is based on a truck-mounted concrete pump. An automatically controlled boom with a reach of 26 metres applies concrete in several layers using a special pressure head based on a predefined digital construction plan. In this way, storey-high, supporting concrete walls are produced that are room-sealing, thus preventing the spread of flames and smoke in the event of a fire.

Until now, concrete 3D printing had limited scalability for large-scale projects. The printing has primarily been carried out by so-called gantry printers, which are limited to the production of smaller buildings. Compared to other concrete printing processes, according to Züblin, “KARLOS has greater flexibility and range as a mobile construction machine and therefore also offers the potential for scalability for large-scale projects.”

The production method includes complete elimination of formwork, the production of solid wall cross-sections in a single operation and the use of CO2-reduced concretes. The project was made using only green electricity.

Photo: Züblin