4. Construction
Construction 3D printing offers various technologies that use 3D printing as the main way of fabricating buildings or construction components.
3D printing applications that are used in construction include extrusion (concrete/cement, wax, foam, and polymers), powder bonding (polymer bond, reactive bond, sintering) and additive welding. 3D printing in construction has a wide array of applications in the private, commercial, industrial and public sectors. Advantages of these technologies include allowing more complexity and accuracy, faster construction, lower labor costs, greater functional integration, and less waste.
The first fully completed residential building was constructed in Yaroslavl, Russia in 2017. 600 elements of the walls were printed in a shop and assembled on site, followed by completion of the roof structure and interior decoration for a total area of 298.5 sq meters (3213 sq ft). The project represents the first time in the world the entire technological cycle had passed building requirements, from design, building permit, registration, to connection of all engineering systems. The building was not built just for presentation, today a real, normal family lives in it.
Concrete 3D printing has been in development since the 1990s, as a faster and less expensive way of constructing buildings and other structures. Large-scale 3D printers designed specifically for printing concrete can pour foundations and build walls onsite. They can also be used for printing modular concrete sections that are later assembled on the job site.
In 2016, the first pedestrian bridge was 3D printed in Alcobendas, Madrid, Spain. It was printed in micro-reinforced concrete at a length of 12 meters (39 ft) and width of 1.75 meters (5.7 ft). The bridge illustrates the complexities in the forms of nature and was developed by both parametric (using a set of rules, values, and relationships that guide the design) and computational design, allowing the optimal distribution of materials while maximizing structural performance.
It was a milestone in the international construction industry, being the first large-scale application of 3D printing technology in the field of civil engineering in a public space.
3D printing is used to produce architectural scale models, enabling a faster turnaround of the scale model and increasing the overall speed and complexity of the objects produced.
As a futuristic concept, 3D printing is being studied as a technology for constructing extraterrestrial habitats, such as habitats on the Moon or Mars. It has been proposed, using building-construction 3D printer technology, fabricating lunar building structures with enclosed inflatable habitats for housing human occupants inside the hardshell lunar structures. These habitats would need only ten percent of the structure to be transported from Earth, using local raw lunar materials for the other 90 percent of the structure.
