Bloom, a 3D-printed, powder-based cement structure, may prove a viable option for architecture in the future.
Exploring the use of 3D printing technology in architecture and construction, a research team at the University of California, Berkeley, has constructed the largest powder-based, 3D-printed cement structure to date. The freestanding temple-like pavilion, entitled Bloom, was unveiled early in March this year.
Standing almost 2,75m tall and spanning a surface area of about 3,66m wide, it is built out of 840 customised blocks, each one numbered to designate its exact position in the structure. Rather than a set of blueprints, a spreadsheet showing the position of every block was used to assemble the building.
Each block has been uniquely designed with a mottled pattern that lets varying amounts of light and shade through to the interior. Assembled, the blocks create a decorative flower pattern on the outer surface that together with the curved cross shape of the building, reminds of the traditional Tiébélé mud houses in Burkino Faso and Ghana.
The pavilion functions as a load-bearing enclosure and doesn’t require any additional structural support since each block contains a printed structural grid. The curved shape also adds rigidity to the thin, lightweight structure.
The blocks were printed by eleven powder 3D printers, which can produce approximately 30 blocks a day. A cement polymer formulation that comprises iron oxide-free Portland cement and a UV-resistant polymer was used. Since iron oxide gives cement its grey colour, its removal makes this print much lighter. The polymer was ecologically derived and reduces the greenhouse gas emissions from the production of resins by 50% over conventional petroleum-based epoxies that use plant-based materials.
The experimental 3D-printed cement polymer structure was designed by an associate professor of architecture, Ronald Rael, who led the year-long research project. The Bloom venture overcame many of the previous limitations associated with 3D-printed architecture, such as the speed and cost of production, as well as aesthetics and practicality.
Rael explains that while most other experiments involve wet cement being extruded through a nozzle to produce rough panels, in this case mixing polymers with cement and fibres to produce strong, lightweight, high-resolution parts on readily available equipment proved to be a very precise and economical technique. 3D-printed cement requires no formwork, produces no waste and the support material can be reused to produce more blocks, which makes it a potentially marketable option.
Full thanks and acknowledgement are given to UC Berkeley, Emerging Objects and Architectural Record for the information given to write this article.