For the past few decades, 3D printing also known as Additive Manufacturing has been the trend talk at the Construction and Manufacturing industries of international forums. Dating back to the birth of this technology, no one had a clue that this automation is yet to revolutionize the construction domain. The boom started, when Betroth Khoshnevis patented his Contour Crafting technology in 1995. 3D printers adopt different technologies based on the required scope for a domain. It includes Stereolithography, Selective Laser Sintering, Electron Beam Melting, and Fused Deposition Modeling(FDM). Till now, the Majority of 3D printed construction projects have been implemented with an adapted version of FDM 3D printers, where the concrete is extruded instead of any other filament.
These FDM printers are classified as Cartesian, Delta, Polar, and FDM with Robotic arms, based on the characteristics of their extruding arm. Robotic arm FDM processed by Contour Crafting is the most widely used 3D printing technology in the Construction industry, due to its overwhelming advantages over other types.
These printers receive the computer-based 3D model as STL file format and further process it as layer-by-layer data and print the output 3D object. In the case of 3D printed buildings, walls and other components of the building are printed layer by layer upon extruding of concrete by the robotic arm, this eliminates many additional works which were needed in conventional construction and it also reduces time much effectively.
Concrete used here differs from conventional concrete by, getting hardened within few minutes of exposure to the atmosphere and has unique composition and properties. China’s Win Sun has been a forerunner in 3D printed buildings with 10 full-sized single-story houses built in 24 hrs.
The same firm proved its efficacy once again when it completed the world’s first apartment building in China. Many other firms started to rise as trailblazers, where ACCIONA(a Spanish firm), IAAC inaugurated the world’s first 3D printed pedestrian bridge in Madrid, and CAZZA, a Dubai-based firm has announced on world’s first 3D printed skyscraper. As the trend in 3d printing increases linearly with time, many technologies are being invented by private firms, examples of which, include FreeFAB Wax, D-shape technology.
Although new initiatives are being established, one of the bottleneck aspects in this field is the reinforcement provided for concrete in the conventional methods cannot be incorporated in the 3D printing method, which stops this technology from the large-scale application.
This specific area is still under study, whereas alternatives such as Ferrocement, Textile reinforcement meshes, Spatial meshes as concrete formwork are still under suggestion. However, the rate at which the R&D, Digitalization increases in today’s world, the scope of 3d printing will be humongous, clearing all of the current discrepancies. Also, it would have the potential to revitalize and revolutionize the residential and building sector which has never seen huge innovation in the past years.
WHY 3D PRINTING IN CONSTRUCTION:-
Firstly, 3D printing concrete saves a lot of time. In particular, using these technologies potentially reduces a 2-week job to just 3-4 days. Moreover, this reduces the risks of injury at work. BENOIT FURET at the University of Nantes explains “the reduction of the hardship and the risks is a reality, we realized rays of 3.8m of height without any scaffolding. In addition, the construction site is very quiet.”
His team managed to print in 3D a 95m² house, and the first 3D printed social housing in the city. Benoit says their BatiPrint technology has also made it easier to create curved shapes at a lower cost. Moreover, as 3D printers don’t need to eat or sleep, they don’t stop working until the project is finished. This greatly reduces waiting times.
Fig 2:- Model of 3d printing house3D printing in space:-
While coming to 3d printing in space the additive manufacturing could also be a way for humanity to explore space. NASA has launched the ‘3D Printed Habitat Challenge‘ examining technologies used to build homes in space, such as on the Moon or on Mars. Although ambitious, it is too early to tell if 3D printing is a viable solution. We can tell, however, that 3D printing in construction is to become a very real global force. SmarTech Publishing recently published a report predicting global revenues in the sector to be $40bn in 2027. To go from a few million dollars to $40bn in 10 years is astonishing. Therefore, we will have to see how the world reacts to this tech in the future.
Fig 3:- Russian company Apis Cor built this house in just 24 hours using their concrete 3d printer.
CONTOUR CRAFTING TECHNOLOGY:-
The Contour Crafting technology demonstrated all the qualities needed to use additive manufacturing on construction sites: reduction in costs and waste, faster construction speed, reduction of accidents, complex architectural shapes, and more. His discovery marked the beginning of 3D printing in construction. However, it remains much less used than certain sectors such as aeronautics or medical.
Construction giants are quickly realizing the potential of 3D technologies and their impact on the future of construction. The concrete 3D printing market is expected to reach $56.4m in 2021, and with good reason. More and more companies are starting up in the sector to create new, innovative projects. Some are more futuristic, some are very real in the present, such as Apis Cor’s 3D printed house in 24 hours. 3D concrete printing is developing rapidly and relies on different technologies and materials, offering many benefits to its users. The tech is still in its infancy however and is bound by current limitations.
Fig:-5 large-scale industrial concrete printers can create house structures automatically.
Fig:6 future opportunities in 3d printing construction market
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