Construction 3D printing
Construction 3D printing refers to various technologies that use 3D printing as a core method to fabricate buildings or construction components. Current machines are being integrated into automated and semi automated production lines and, because of the scale of construction, will feature elements of additive, subtractive and formative manufacturing processes, to handle material deposition at one scale and finishing at another. Because of the cost, 3D printing at construction scales demands clever design and can respond to the demands of architects and engineers for high value, high performance building components. Potential advantages of these technologies include faster construction, lower labor costs, increased complexity and/or accuracy, greater integration of function and less waste produced. There are a variety of 3D printing methods used at construction scale, these include the following main methods: extrusion (concrete/cement, wax, foam, polymers), powder bonding (polymer bond, reactive bond, sintering) and additive welding. 3D printing at a construction scale will have a wide variety of applications within the private, commercial, industrial and public sectors. Development has been slow and sporadic, since its development in the mid 1990's, where initially it was explored as a scaled version of mainstream 3D printing, having both novelty value and early research funding in both the US and Europe. The term 'Construction 3D Printing' was first coined by James B Gardiner in 2011 
A number of different approaches have been demonstrated to date which include on-site and off-site fabrication of buildings and construction components, using industrial robots, gantry systems and tethered autonomous vehicles. Demonstrations of construction 3D printing technologies to date have included fabrication of housing, construction components (cladding and structural panels and columns), bridges, artificial reefs, follies and sculptures. Current efforts focus on integrating the advantages of digital fabrication within factory based construction manufacturing. Stand alone and on-site machines are in planning and research, ranging from modified autonomous concrete/gypsum/mineral paste pumping/spraying, composite fiber spinning and ultimately swarm construction agents, where construction 3D printing merges with robotics and AI systems. Pilot studies have demonstrated that construction 3D printing may be well suited for construction of extraterrestrial structures on the Moon or other planets, where environmental conditions are less conducive to human labor-intensive building practices.
- 1 History
- 2 See also
- 3 References
- 4 External links
Seeding technologies 1950 - 1995
Robotic bricklaying was conceptualized and explored in the 1950's and related technology development around automated construction began in the 1960s, with pumped concrete and isocyanate foams. Development of automated fabrication of entire buildings using slip forming techniques and robotic assembly of components, akin to 3D printing, were pioneered in Japan to address the dangers of building high rise buildings by Shimizu and Hitachi in the 1980s and 1990s. Many of these early approaches to on-site automation foundered because of the construction 'bubble', their inability to respond to novel architectures and the problem of feeding and preparing materials to the site in built up areas.
Early developments 1995 - 2000
Early construction 3D printing development and research have been under way since 1995. Two methods were invented, one by Joseph Pegna  which was focused on a sand/cement forming technique which utilized steam to selectively bond the material in layers or solid parts: this technique was never demonstrated. The second technique, Contour Crafting by Behrohk Khoshnevis, initially began as a novel ceramic extrusion and shaping method, as an alternative to the emerging polymer and metal 3D printing techniques, and was patented in 1995. Khoshnevis realized that this technique could exceed these techniques where "current methods are limited to fabrication of part dimensions that are generally less than one meter is each dimension". Around 2000, Khoshnevis's team at USC Vertibi began to focus on construction scale 3D printing of cementitious and ceramic pastes, encompassing and exploring automated integration of modular reinforcement, built-in plumbing and electrical services, within one continuous build process. This technology has only been tested at lab scale to date and controversially and allegedly formed the basis for recent efforts in China.
First Generation 2000 - 2010
In 2003, Rupert Soar secured funding and formed the freeform construction group at Loughborough University, UK, to explore the potential for up-scaling existing 3D printing techniques for construction applications. Early work identified the challenge of reaching any realistic break-even for the technology at the scale of construction and highlighted that there could be ways into the application by massively increasing the value proposition of integrated design (many functions, one component). In 2005, the group secured funding to build a large-scale construction 3D printing machine using 'off the shelf' components (concrete pumping, spray concrete, gantry system) to explore how complex such components could be and realistically meet the demands for construction.
In 2005 Enrico Dini, Italy, patented the Monolite/D-Shape technique, employing a massively scaled powder jetting/bonding technique over an an area approximately 5m x 5m x 2.5m. This technique although originally developed with epoxy resin bonding system was later adapted to use inorganic bonding agents. This technology has been used commercially for a range of projects in construction and other sectors including for [artificial reefs].
In 2008 3D Concrete Printing began at Loughborough University, UK, headed by Richard Buswell and colleagues to extend the groups prior research and look to commercial applications moving from a gantry based technique  to an industrial robot, which they succeeded in licensing the technology to Skanska in 2014.
Voxeljet is a powder printing technique that was scaled up to have the capability to produce construction components.
Mineraljet was a proposal for construction 3D printing technology using high density gypsum. This technology has yet to be demonstrated.
Second Generation 2010 - present
Winsun (Shanghai WinSun Decoration Design Engineering Co) launched their concrete printer on April fools day 2014 with an article on 3ders. The company claimed to have printed 10 houses in a day each 200m2, however visual scaling from the photographs does not support the claim for the buildings size. The demonstration of a large number of 3D printed buildings however was the first of its kind and indicates the capability of the construction 3D printer developed.
On January 18, 2015 the company gained further press coverage with the unveiling of 2 further buildings, a mansion style villa and a 5 storey tower, using 3D printed components. Detailed photographic inspection indicates that the buildings were fabricated with both precast and 3D printed components. The buildings stand as the first complete structures of their kind fabricated using construction 3D printing technologies. In May 2016 a new 'office building' was opened in Dubai. The 250-square-metre space (2,700 square foot) is what Dubai's Museum of the Future project is calling the world's first 3D-printed office building.Although Winsun claim to have been working on 3D printing for many years, no publicly available information has been found to support the claim.
FreeFAB Wax™, invented by James B Gardiner and Steven Janssen at Laing O'Rourke (construction company). The patented technology has been in development since March 2013. The technique uses construction scale 3D printing to print high volumes of engineered wax (up to 400L/hr) to fabricate a 'fast and dirty' 3D printed mould for precast concrete, glass fibre reinforced concrete (GRC) and other sprayable/cast-able materials. The mould casting surface is then 5 axis milled removing approximately 5mm of wax to create a high quality mould (approximately 20 micron surface roughness). After the component has cured, the mould is then either crushed or melted-off and the wax filtered and re-used, significantly reducing waste compared to conventional mould technologies. The benefits of the technology are fast mould fabrication speeds, increased production efficiencies, reduced labour and virtual elimination of waste by re-use of materials for bespoke moulds compared to conventional mould technologies.
The system was originally demonstrated in 2014 using an industrial robot. The system was later adapted to integrate with a 5 axis high speed gantry to achieve the high speed and surface milling tolerances required for the system. The first industrialised system is installed at a Laing O'Rourke factory in the United Kingdom and is due to start industrial production for Crossrail's London underground stations in late 2016.
MX3D Metal (information required)
Design for construction 3D printing
Dutch architect Janjaap Ruijssenaars's performative architecture 3D-printed building was planned to be built by a partnership of Dutch companies.[needs update]  The house was planned to be built in the end of 2014, but this deadline wasn't met. The companies said that they are still 100% sure the house will be printed.
Various approaches to building printing are being researched. Two of these are Contour crafting and D-Shape. Other approaches involve direct sintering of inorganic raw materials to build composite ceramic building structures, similar to the approach used with metals in direct metal laser sintering.
3D printed residential buildings
In the Netherlands, DUS Architects is 3D printing a 3D Printed Canal House, together with an international team of partners. The 3D Print Canal House links science, design, construction and community at an open building site in the heart of Amsterdam. Their aim is to demonstrate how 3D printing could revolutionize construction by increasing efficiency and reducing pollution and waste, and offer new tailor made housing solutions worldwide. 3D printing could also play a significant role in the quick build of low-cost housing in impoverished areas and those affected by disasters. The 3D Print Canal House is currently under construction at a canal-side plot in Amsterdam – an open ‘expo-site’ that it is proving to be a popular visitor attraction for the public. At the heart of the site, is the Kamermaker, or Room Builder – which is essentially a scaled-up version of a table-top 3D printer. The Kamermaker prints building blocks from molten bio-plastic. This is currently a mix of 80% plant oil reinforced with microfibers, although this formula is still under development with the project’s materials partner Henkel. For reinforcement, the blocks have an internal honeycombed centre that can be back-filled with Eco concrete. It also provides space for pipes, wiring and data cables to be installed internally.
The building blocks are then used to form component parts that can be slotted together like Lego to create a 4-storey, 13-room structure modelled on a traditional Dutch canal house. One of the most distinct design features of the Canal House is its geometrically faceted plastic façade. 3D Print House Building BlocksThis gives a contemporary 3D print twist to the traditional canal house silhouette. The ability to print ornamental detailing on demand is a key design benefit of 3D modelling and printing in the building industry. With costly labour-intensive work reduced, custom-designed homes would become more accessible. So what are the main benefits of printing a house? Waste materials are a big problem for the building industry, but with 3D printing only the necessary raw materials are produced for each project. An added bonus is that 3D printer ‘ink’ can be made from recycled plastic waste. If printing on site, transport costs and CO2 emissions are greatly reduced – as are dust and noise levels. And when the building is no longer needed, it can be shredded and recycled. Another key driver for developing this technology within the construction industry is the growing need for rapidly produced housing. In this respect, 3D printing has the potential to reshape the way in which we build our cities – especially as Megacities are on the increase around the globe. The 3D Print Canal House was the first full-scale construction project of its kind to get off the ground. In just a short space of time, the Kamermaker has been further developed to increase its production speed by 300%. However, progress has not been swift enough to claim the title of ‘World’s First 3D Printed House’.
Dutch and Chinese demonstration projects are slowly constructing 3D-printed buildings, using the effort to educate the public to the possibilities of the new plant-based building technology and to spur greater innovation in 3D printing of residential buildings.
Claims have been made by Behrokh Khoshnevis since 2006 for 3D printing a house in a day, with further claims to notionally complete the building in approximately 20 hours of "printer" time. By January 2013, working versions of 3D-printing building technology were printing 2 metres (6 ft 7 in) of building material per hour, with a follow-on generation of printers proposed to be capable of 3.5 metres (11 ft) per hour, sufficient to complete a building in a week. The Chinese company WinSun has built several houses using large 3D printers using a mixture of quick drying cement and recycled raw materials. Ten demo houses were built in 24 hours, each costing US$5000. However, construction 3D printing pioneer Dr. Behrokh Khoshnevis claims this was faked and that WinSun stole his intellectual property.
Extraterrestrial printed structures
As of 2013[update], the European Space Agency was working with London-based Foster + Partners to examine the potential of printing lunar bases using regular 3D printing technology. The architectural firm proposed a building-construction 3D-printer technology in January 2013 that would use lunar regolith raw materials to produce lunar building structures while using enclosed inflatable habitats for housing the human occupants inside the hardshell printed lunar structures. Overall, these habitats would require only ten percent of the structure mass to be transported from Earth, while using local lunar materials for the other 90 percent of the structure mass.
The dome-shaped structures would be a weight-bearing catenary form, with structural support provided by a closed-cell structure, reminiscent of bird bones. In this conception, "printed" lunar soil will provide both "radiation and temperature insulation" for the Lunar occupants. The building technology mixes lunar material with magnesium oxide which will turn the "moonstuff into a pulp that can be sprayed to form the block" when a binding salt is applied that "converts [this] material into a stone-like solid." A type of sulfur concrete is also envisioned.
Tests of 3D printing of an architectural structure with simulated lunar material have been completed, using a large vacuum chamber in a terrestrial lab. The technique involves injecting the binding liquid under the surface of the regolith with a 3D printer nozzle, which in tests trapped 2 millimetres (0.079 in)-scale droplets under the surface via capillary forces. The printer used was the D-shape.
In early 2014, NASA funded a small study at the University of Southern California to further develop the Contour Crafting 3D printing technique. Potential applications of this technology include constructing lunar structures of a material that could consist of up to 90-percent lunar material with only ten percent of the material requiring transport from Earth.
NASA is also looking at a different technique that would involve the sintering of lunar dust using low-power (1500 watt) microwave energy. The lunar material would be bound by heating to 1,200 to 1,500 °C (2,190 to 2,730 °F), somewhat below the melting point, in order to fuse the nanoparticle dust into a solid block that is ceramic-like, and would not require the transport of a binder material from Earth as required by the Foster+Partners, Contour Crafting, and D-shape approaches to extraterrestrial building printing. One specific proposed plan for building a lunar base using this technique would be called SinterHab, and would utilize the JPL six-legged ATHLETE robot to autonomously or telerobotically build lunar structures.
- J.B.Gardiner  PhD Thesis - Exploring the Emerging Design Territory of Construction 3D Printing (p42), 2011
- Papanek (1971). Design for the Real World. ISBN 978-0897331531.
- Architectural Design (2008). "Versatility and Vicissitude". ISBN 9780470516874.
- J.B.Gardiner  PhD Thesis - Exploring the Emerging Design Territory of Construction 3D Printing (p80), 2011
- Khoshnevis,  Original Contour Crafting Patent US5529471 A,
- Patent by Dini et. al,  "Method and Device for Building Automatically Conglomerate Structures. Patent number US20080148683 A1" ] web cited 2016-07-18
- J.B.Gardiner PhD thesis  "Exploring the Emerging Design Territory of Construction 3D Printing, 2011 (p89) web cited 2016-07-18
- J.B.Gardiner PhD thesis  "Exploring the Emerging Design Territory of Construction 3D Printing, 2011" (p337) web cited 2016-07-18
- J.B.Gardiner PhD thesis  "Exploring the Emerging Design Territory of Construction 3D Printing, 2011 (p81) web cited 2016-07-18
- "http://www.3ders.org/articles/20140401-10-completely-3d-printed-houses-appears-in-shanghai-built-in-a-day.html" web cited 2016-09-14
- "https://3dprint.com/38144/3d-printed-apartment-building/" web cited 2016-09-14
- "https://3dprint.com/126426/3d-printed-museum-office/" web cited 2016-09-14
- "http://link.springer.com/chapter/10.1007/978-3-319-04663-1_9" RobArch 2014 conference proceedings, Springer web cited September 14, 2016
-  "Freefab: Development of a construction-scale robotic formwork 3D printer", Vimeo 2014]
- "http://www.iaarc.org/publications/fulltext/ISARC2016-Paper095.pdf, ISARC 2016"
- "FreeFAB Technology", Youtube 2014-10-09
- "Linkedin profile James B Gardiner", Linkedin cited 2016-07-20
- 3D printed Landscape House
- "The World's First 3D-Printed Building Will Arrive In 2014". TechCrunch. 2012-01-20. Retrieved 2013-02-08.
- Video summary of Landscape house forum and workshop Sept 3rd 2014
- "NASA's plan to build homes on the Moon: Space agency backs 3D print technology which could build base". TechFlesh. 2014-01-15. Retrieved 2014-01-16.
- Edwards, Lin (19 April 2010). "3D printer could build moon bases". Phys.org. Retrieved 21 October 2013.
- Cesaretti, Giovanni; Enrico Dini; Xavier de Kestelier; Valentina Colla; Laurent Pambaguian (January 2014). "Building components for an outpost on the Lunar soil by means of a novel 3D printing technology". Acta Astronautica. 93: 430–450. doi:10.1016/j.actaastro.2013.07.034. Retrieved 4 November 2013.
- Steadman, Ian. "Giant Nasa spider robots could 3D print lunar base using microwaves (Wired UK)". Wired.co.uk. Retrieved 2014-03-13.
- "How Dutch team is 3D-printing a full-sized house". BBC. 2014-05-03. Retrieved 2014-06-10.
- The plan to print actual houses shows off the best and worst of 3D printing (2014-06-26), James Robinson, PandoDaily
- "Contour Crafting". YouTube. 2006-04-27. Retrieved 2016-07-18.
- "3D printer can build a house in 20 hours". YouTube. 2012-08-13. Retrieved 2014-03-13.
- Diaz, Jesus (2013-01-31). "This Is What the First Lunar Base Could Really Look Like". Gizmodo. Retrieved 2013-02-01.
- "China's Building 3D Printed Houses". Investing.com. Retrieved 2014-08-23.
- "China: Firm 3D prints 10 full-sized houses in a day". www.bbc.com. Retrieved 2014-04-28.
- Giant 3D printer creates 10 full-sized houses in a DAY: Bungalows built from layers of waste materials cost less than £3,000 each, Daily Mail, 28 April 2014, accessed 16 May 2014.
- "Building a lunar base with 3D printing / Technology / Our Activities / ESA". Esa.int. 2013-01-31. Retrieved 2014-03-13.
- "3D Printing of a lunar base using lunar soil will print buildings 3.5 meters per hour". Newt Big Future. 2013-09-19. Retrieved 2013-09-23.
- "3D printed moon building designs revealed". BBC News. 2013-02-01. Retrieved 2013-02-08.
- "NASA - 3D Printing In Zero-G Technology Demonstration". Nasa.gov. 2014-03-04. Retrieved 2014-03-13.