3D Concrete House Printer

April 21, 2014.

While society is still wondering if we are ready for 3D printing in construction, a new era of 3D architecture has already begun. Originating from the RepRap project, this 3D House Cement Printer is built to print medium-sized homes. The printer’s design is based on the harsh realities of the construction world, taking into consideration environmental factors such as temperature variability and strong winds.

The main task while developing this technology is to minimize the number of operations and reduce the amount of material required to construct a building. The blueprint is centered on simplicity, easy maintenance, and parts replacement, and since the transportation of large structures over long distances is problematic and expensive, the printer’s complicated knots are simplified so they can be taken apart, shipped, and then put together at any time.

3D printing in construction will not wholly replace previous techniques, and materials such as brick will continue to be utilized. Rather, 3D printing will significantly supplement the manual work. The technology aims to considerably lower production cost, provide a safer and more comfortable building process, and allow for much more architectural flexibility. In place of an entire group of construction workers, two people will facilitate the 3D printing process: one with appropriate computer skills in charge of the programming, and one working with the materials (e.g. sand and cement), placing reinforcing steel bars inside the forms, and maintaining the machine at the end of the day and so forth.

The project video shows a finished prototype of the 3D Cement Printer at work. The current model fits inside a 2-car garage and is able to vertically raise walls from cement for a shape defined by g-code. The goal is to print the cement formwork in a configuration of any complexity and fill the formwork with poured concrete or other insulating material. After a series of experiments, I believe I have resolved several basic problems that stumped my colleagues regarding insulation, wall reinforcement, wiring, and pipes.  Proper insulating materials should add a sufficient strength to the structural concrete wall.

A 3D house made out of insulating concrete forms will be warm and durable, as well as less susceptible to damage from earthquakes, floods, hurricanes, fires, and other natural disasters.  Plumbing and electrical and communication wiring can be placed inside the forms. It is also important to find out if this project will work at low temperatures. A printing experiment conducted in winter temperatures (slightly above 32 °F or 0 °C) is captured in the video. In reality, cement printing will be performed in standard weather conditions, i.e. spring – summer. However, it was confirmed that printing at zero degrees may take longer than printing during a warm temperature but attains equally good result.

Presently, the 3D House Printer is at stable operating conditions and capable of printing layers of different configurations. While other teams are also working on respectable projects in 3D printing construction technology, I have developed a product that is ready for actual-size construction rather than miniature prototypes. My next step is to print a real two-story house, currently planned to have dimensions of 10 m x 15 m. It will require a fair amount of effort, resources and time, and I will post updates on the progress.

Andrey Rudenko,