In this blog post, we will look at whether the technology of building a house with a 3D printer is actually possible, how it is implemented, and what its limitations and possibilities are.
Even if you don’t know much about 3D printers, there are probably not many people who haven’t heard of them. 3D printers have recently been widely reported in the media and various other outlets, and have become a hot topic. While conventional printers show 2D results on paper, 3D printers create 3D results through a layer-by-layer method. Mathematically, conventional printers move only along the x- and y-axes to create results, while 3D printers move up and down along the z-axis to create results.
In fact, 3D printers have been commercialized since 1988, but they began to be widely known to the public in February 2013 after President Obama mentioned the enormous potential of 3D printers. This led to 3D printers being widely publicized to the general public through the media and receiving a lot of attention. 3D printers are now widely used in various fields, and they 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 material is put into the 3D printer. If you use a material like plastic, you can make various models, and if you use hyperelastic bone, you can make medical supplies that can be implanted into human bones to help them regenerate and synthesize quickly. So, is it possible to build a house by putting concrete in a 3D printer? There is a company that has provided the answer to this question. It is the Chinese construction company WINSUN. This company has attracted the attention of the world by using 3D printers in construction to quickly create various buildings, and has also participated in the construction of the “3D printer-made office,” one of the “Future Museum” projects in Dubai.
Considering that most of the things that humans make are 3D, it can be inferred that a lot of things can be made with 3D printers. It is being used in various fields, including consumer goods, electronics, dentistry, aviation, and automobiles, and its scope is gradually expanding. Compared to the aforementioned fields, the construction industry has been relatively late in adopting 3D printing technology. 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 it difficult to print them with 3D printers.
The fact that 3D printers can also be applied to the construction sector 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 used it and applied it in practice. In January 2015, WINSUN built 10 houses in 24 hours using a 3D printer, which was reported in the media and became a hot topic. It is difficult to build one floor of a building in 24 hours, and the fact that 10 houses were built in that time came as a shock to many people. People’s shock did not stop there. I was shocked to learn that the price of a single house was only $5,000. WINSUN even used an eco-friendly material that is a mixture of cement and construction waste as the material for the 3D printer.
Although the houses built with 3D printers at this time were not yet ready for human habitation, they were a good example of how quickly houses can be built with 3D printers. What was the secret behind WINSUN’s ability to build so many buildings in such a short time? WINSUN modularized the buildings to be built and printed them out in advance using a 3D printer before coming to the site, and assembled them on site. Simply put, they made the chunks in advance and just glued them together on site. In the conventional construction method, there was also a method called the “precast method” in which construction members made in the factory were assembled on site. However, this method takes much longer than 3D printing because it requires additional time to make the formwork for pouring concrete, pour concrete into the formwork, and allow the concrete to harden. After concrete is poured at a regular construction site, it undergoes a process called “curing” to protect it from impact and allow it to harden properly so that it can perform to its full potential. The curing process varies depending on the temperature and humidity, but generally takes about 4 to 12 days. In order for concrete to have high strength, it is better to cure it in a wet state, and for this purpose, the concrete is covered with plastic during the curing process. After the curing process is complete, the plastic and the formwork that held the concrete must also be removed, which also takes some time. Using a 3D printer has the advantage of greatly reducing the time spent on these parts.
Although 3D printers have the great advantage of being able to build houses quickly, they also have disadvantages. Most existing high-rise buildings are reinforced concrete structures that use a combination of steel and concrete. Reinforcing steel is strong in tensile force (pulling force) but weak in compressive force (pushing force), while concrete is weak in tensile force but strong in compressive force. In other words, using reinforcing steel and concrete together can achieve good performance in both tensile and compressive forces. High-rise buildings that receive a lot of load almost always use reinforced concrete structures, but there are difficulties in using 3D printers to create reinforced concrete structures. This is because it is not easy to use steel pulled out by a 3D printer immediately, and even if the existing steel bars are covered with concrete, it is difficult to ensure good adhesion between the steel bars and the concrete. Because of this, the number of buildings built with 3D printers has been limited to a maximum of 10 floors.
The 3D printing architecture technology, first introduced by Professor Behrokh of the University of Southern California (USC), was directly applied to real life by Chinese construction company WINSUN and caused a huge sensation. Their unique technology has been successfully applied in many parts of the world, proving its viability. For example, Contour Crafting is being used to build low-cost housing and emergency shelters, making it particularly useful in disaster recovery situations. A large number of luxury villas were also supplied by a real estate development company in Taiwan. This is a good example of how 3D printing technology for buildings can be used to quickly build a large number of buildings. Because of this feature, 3D printing technology for buildings is attracting attention as a way to quickly restore areas affected by disasters.
WINSUN is not the only company to apply 3D printing technology to the construction sector. Efforts are ongoing around the world to apply 3D printing technology to the construction sector. Professor Behrokh’s research team at the University of Southern California (USC) is researching a system that prints entire structures directly on site, while Professor Buswell’s research team at Loughborough University in the UK is researching the formulation of printing materials for high-performance printing concrete. Some buildings are atypical, such as the Sydney Opera House, which has no fixed shape or form. As 3D printing technology for buildings advances, it will be of great help in building atypical buildings.
Compared to the share of the construction industry in the global industry, the share of the construction sector in 3D printers is only about 4%. In addition, there are not many patent applications related to 3D printing technology for buildings. Based on these facts, 3D printing technology for buildings has a lot of room for development and is a technology that is expected to make progress in the future.
