In this blog post, we will examine whether the technology to build houses with 3D printers is actually possible, how it can be implemented, and what its limitations and possibilities are.
Even if you don’t know much about 3D printers, you’ve probably heard of them. 3D printers have been widely reported in the media and have become a hot topic. While conventional printers produce 2D results on paper, 3D printers produce 3D results through a layer-by-layer process. Mathematically speaking, conventional printers move only along the x and y axes to produce results, but 3D printers add the z axis to move up and down to produce results.
In fact, 3D printers have been commercially available since 1988, but they only became widely known to the general public in February 2013, after President Obama mentioned the enormous potential of 3D printers.
As a result, 3D printers became widely known to the general public through the media and attracted a lot of attention. Currently, 3D printers are widely used in various fields and are even used to make food and clothes. The biggest reason why 3D printers can be widely used in various fields is that what can be made depends on what materials are put into the 3D printer.
Plastic can be used to make various models, and hyperelastic bone can be used to make medical devices that can be implanted into human bones to accelerate bone regeneration and synthesis. So, is it possible to build a house by putting concrete into a 3D printer? There is a company that has provided the answer to this question. That company is WINSUN, a Chinese construction company. This company has attracted attention by quickly constructing various buildings using 3D printers, and has also participated in the construction of an office building made with a 3D printer, which is one of Dubai’s “Future Museum” projects.
Considering that most of the things made by humans are 3D, it is easy to imagine that a lot can be made with a 3D printer. They are used in various fields such as consumer goods, electronics, dentistry, aviation, and automobiles, and their scope is gradually expanding. Compared to the fields mentioned above, 3D printing technology has been applied to the construction field relatively recently. There are many reasons for this, but the main reason is that houses are directly related to human safety, and buildings are large in scale, making them difficult to print with a 3D printer.
The fact that 3D printers can be applied to the construction field became widely known through the Chinese construction company WINSUN. 3D printer construction technology was first introduced by Professor Behrokh of the University of Southern California, but WINSUN actively utilized it and applied it in practice. In January 2015, WINSUN built 10 houses in 24 hours using 3D printers, which was reported in the media and became a hot topic. It is difficult to even build one floor of a building under construction in 24 hours, so the fact that 10 houses were built in that time came as a shock to many people. But that wasn’t the only thing that shocked people. They were also shocked to learn that each house cost only $5,000. WINSUN even used an eco-friendly material made from a mixture of cement and construction waste as the material for the 3D printer.
Although the houses built with 3D printers at that time were not yet ready for people to live in, it was a good example of how 3D printers can be used to build houses very quickly. What was the secret behind WINSUN’s ability to build so many buildings in such a short period of time? WINSUN modularized the buildings to be constructed, printed them in advance using a 3D printer before arriving at the site, and assembled them on site. In other words, they made the pieces in advance and simply attached them on site. In conventional construction methods, there was already a method called “precast construction,” in which construction components were manufactured in advance at a factory and then assembled on site. However, unlike 3D printing, this method requires additional time to make the formwork for pouring concrete, pour the concrete into the formwork, and allow the concrete to harden, which takes much longer than 3D printing. In general construction sites, after pouring concrete, it undergoes a process called “curing” to protect it from impact and allow it to harden properly so that it can perform at its best. The curing process varies depending on the temperature and humidity, but generally takes about 4 to 12 days. In order for concrete to achieve high strength, it is best to cure it in a moist state, and for this purpose, the concrete is covered with plastic during the curing process. Once the curing process is complete, the vinyl and formwork used to hold the concrete in place must be removed, which also takes some time. Using a 3D printer has the advantage of significantly reducing the time required for this process.
Although 3D printers have the great advantage of being able to build houses quickly, they also have some disadvantages. Most existing high-rise buildings are reinforced concrete structures that use both steel bars and concrete. Steel bars are strong against tensile force (pulling force) but weak against compressive force (pushing force), while concrete is weak against tensile force but strong against compressive force. In other words, using steel bars and concrete together can achieve good performance in both tensile and compressive forces. High-rise buildings that bear heavy loads almost always use reinforced concrete structures, but there are difficulties in creating reinforced concrete structures using 3D printers. Not only is it difficult to print iron with a 3D printer and use it immediately, but even if concrete is poured over existing steel bars, it is difficult to achieve good adhesion between the steel and the concrete.
Due to these issues, buildings constructed with 3D printers are currently limited to a maximum of 10 stories. 3D printing construction technology, first introduced by Professor Behrokh of the University of Southern California, was applied to real life by Chinese construction company WINSUN, causing a huge sensation. Their unique technology has been successfully applied in various parts of the world, proving the feasibility of this technology.
For example, Contour Crafting is used to build low-cost houses and emergency shelters, which is particularly useful in disaster recovery situations. A real estate developer in Taiwan has also built a large number of luxury villas using this technology. This is a good example of the ability to build large numbers of buildings quickly, which is a feature of 3D printing technology for buildings. Due to this feature, 3D printing technology for buildings is attracting attention for its potential to enable rapid recovery in areas affected by disasters.
WINSUN is not the only company applying 3D printing technology to the construction industry. Efforts to apply 3D printing technology to the construction industry are continuing around the world. Professor Behrokh’s research team at the University of Southern California is researching a system for continuously printing entire structures directly on site, while Professor Buswell’s research team at Loughborough University in the UK is researching the composition of printing materials for high-performance printed concrete. Some buildings, such as the Sydney Opera House, have no fixed shape or form. Advances in 3D printing technology for buildings will greatly facilitate the construction of such buildings.
Compared to the percentage of the global industry accounted for by the construction industry, the construction sector accounts for only about 4% of the 3D printer market. In addition, there are still not many patent applications related to 3D printing technology for buildings. Based on these facts, it can be said that 3D printing technology for buildings has much room for development and is a technology with a promising future.
