3D printers are revolutionizing many fields, using a variety of materials. In the construction sector, they’re gaining traction as a fast and cheap way to build a house. WINSUN, a Chinese company, built a house in less than 24 hours, and the technology has great potential for further development.
Even if you don’t know much about 3D printers, there aren’t many people who haven’t heard of them. 3D printers have been widely publicized and talked about in the press and various media outlets recently. While traditional printers produce 2D results on paper, 3D printers produce 3D results layer-by-layer. Mathematically speaking, traditional printers only move along the x and y axes, while 3D printers move up and down in addition to the z axis.
In fact, 3D printers have been commercialized since 1988, but it wasn’t until February 2013, when President Obama spoke about the enormous potential of 3D printers, that they became widely known to the general public through the media and gained a lot of attention. Today, 3D printers are widely used in a variety of fields, and are even being used to make food and clothes.
The main reason why 3D printers are so widely used is that what you can create depends on what materials you put into the 3D printer. Materials like plastic can be used to create all kinds of models, and hyperelastic bone can be used to create medical devices that can be implanted into human bones to help them regenerate and synthesize faster. But if you can put concrete in a 3D printer, can you build a house? One company has found the answer to that question. WINSUN is a Chinese construction company. The company has made a name for itself by rapidly creating a variety of buildings using 3D printers in construction, and even participated in the construction of a “3D printed office” as part of Dubai’s Museum of the Future project.
Considering that most of the things we make are 3D, you can imagine how many things can be made with a 3D printer. They’re used in consumer goods, electronics, dentistry, aviation, automotive, and more, and the list goes on. Compared to the aforementioned sectors, construction is a relatively recent adopter of 3D printing technology. There are many reasons for this, but one of the main ones is that homes are directly related to human safety, and buildings are not easy to print on a 3D printer due to their large scale.
The application of 3D printers in construction was popularized by the Chinese construction company WINSUN. The 3D printer construction technology was first introduced by Professor Behrokh at USC University in the United States, but WINSUN was the first to take advantage of it and put it into practice. In January 2015, WINSUN built 10 houses in 24 hours using 3D printers, which was reported by the media and made a big splash. The fact that 10 houses were built in such a short time came as a shock to many people, as 24 hours is barely enough time to raise one floor of a building under construction. The shock didn’t stop there. They were also shocked to learn that each house cost only $5,000. WINSUN even used an eco-friendly material for the 3D printer, which is a mixture of cement and construction waste.
Although the 3D printed houses weren’t ready for human habitation, they were a great example of how quickly a 3D printer can build a house, and how quickly it can be built. How did WINSUN manage to build so many structures in such a short time? WINSUN modularized the buildings to be built, printed them on a 3D printer before they arrived on site, and assembled them on site. In other words, the chunks were made in advance and then glued together on site. There is also a conventional construction method called “precast construction,” which involves the assembly of prefabricated building components on site. However, unlike 3D printing, this method is time-consuming compared to 3D printing because it requires additional time to build a mold to pour concrete into, time to pour concrete into the mold, and time for the concrete to set. On a typical construction site, after concrete is poured, it goes through a process called “curing,” which protects it from impact and allows it to harden so that it can perform at its best. The curing process varies depending on the temperature and humidity, but typically takes between four and 12 days. In order for the concrete to develop high strength, it’s best to cure it while it’s still wet, which is why the concrete is covered with plastic during the curing process. Once the curing process is complete, the formwork holding the vinyl and concrete together must be removed, which also takes some time. The advantage of using a 3D printer is that it saves a lot of time in this area.
While 3D printing is a great way to build a house quickly, it also has its drawbacks. Most skyscrapers in existence are reinforced concrete structures, which are a combination of rebar and concrete. Rebar is strong in tension (pulling force) but weak in compression (pushing force), and concrete is weak in tension but strong in compression. This means that the combination of rebar and concrete can perform well in both tension and compression. Reinforced concrete structures are almost mandatory for high-rise buildings that are subjected to heavy loads, but there are challenges to using 3D printers to create them. Not only is it difficult to 3D print steel and use it immediately, but it is also difficult to ensure a good bond between the steel and concrete, even if the concrete is poured over the existing steel. As a result, buildings built with 3D printers to date are only about 10 stories tall at most.
First pioneered by Professor Behrokh at USC University in the United States, 3D printing construction technology was brought to life by the Chinese construction company WINSUN, and it made waves. Their unique technology has been successfully applied in many parts of the world, proving the feasibility of the technology. For example, Contour Crafting has been used to build low-cost housing and emergency shelters, making it particularly useful in disaster recovery situations. It has also been used by a real estate developer in Taiwan for the mass production of luxury villas. This is a great example of the ability to build large numbers of buildings quickly, which is a hallmark of architectural 3D printing technology. Due to this feature, architectural 3D printing technology is also being touted as a fast recovery tool for disaster-stricken areas.
WINSUN is not the only company to apply 3D printing technology to construction. There are efforts around the world to apply 3D printing technology to construction. Prof. Behrokh’s research team at USC is working on a system that continuously prints entire structures directly on site, and Prof. Buswell’s research team at Loughborough University in the UK is studying the formulation of printing materials for high-performance printed concrete. Advances in architectural 3D printing will also help to create unstructured buildings, such as the Sydney Opera House, which has no set shape or form.
Compared to its share of global industry, construction accounts for only about 4% of 3D printers, and there are not many patent applications related to architectural 3D printing technology. These facts suggest that architectural 3D printing has a lot of room for improvement and is an exciting technology to watch.
