The Expanding Role of 3D Printing in Construction
The very first 3D printer was invented in 1984 by Charles Hull in 1984 and it was based on a vat photopolymerization technique called stereolithography. Ever since its invention, it has gone thru several transformations and has been used by several industries like automotive, aerospace, dental, biotech, fashion and design, and the AEC or construction Industry.
3D printing in construction is also called Additive Manufacturing (AM). This involved the computer controlled chronological layering of materials so that a three-dimensional shape can be created. 3D printing in construction exploded ever since Professor Behrokh Khoshnevis from the University of South Carolina tried to print the first 3D wall using an FDM 3D printer that was mounted on a robotic arm that pumps out layers of concrete instead of the plastic that was used by 3 printers at that time.
This was quickly picked up by the construction industry because 3D printing was cheaper, was greener because it produced less waste, it made construction faster, and it allowed for unique architectural shapes to be made. And beuase of this, 3D printing became one of the technologies, in addition to construction project management, and drawing management that the construction expressed a strong intent to use.
Types of 3D Printing in Construction
Ever since Professor Khoshnevis first attempt at printing a wall, there were people who followed in his footsteps and improved on his design. Here are a few ways on how 3D printing or AM is done in the construction industry.
Enrico Dini and His D- Shape Printer
Enrico Dini is an Italian architect who is known as the man who prints 3D houses. He also demonstrated a 3D printing process using his D Shape 3D printer which is 4 x 4 meter in size.
Several coatings of sand are first dropped according to whatever thickness is needed. After that, a print head discharges droplets which contain what is called the binder to solidify the sand. This machine makes it possible to solidify a layer of material with a binder material and can create structures up to 6 cubic meters in size.
3D Printing with A Robotic Arm
This type of method is commonly known as the contour crafting method. In this method, building materials suited for 3D printing are printed and large scale 3D models are created with a smooth surface finish. To be able to do this, rails are installed in the area where the printing will take place. The rails act as a support to direct the robotic arm which then moves back and forth to pump out the building material.
Mx3D and Metal Printing
A Dutch company under the name of MX3D developed a construction 3d printing method called WAAM Wire Arc Additive Manufacturing which allows the printing of 3d metal structures with the help of 6-axis robot. This kind of metal printing can be compared to a very big soldering iron.
The robot was the result of the collaboration between Air Liquide and ArcelorMittal. This 3d printer is capable of welding metal layer by layer thru the use of a welder and a nozzle. This printer can use different kinds of metal such as bronze, aluminum, and Inconel.
3D Printing in the Real World
3D construction has literally moved from the realm to impossibility to the possible. Here are some examples of the object that have been printed via 3D printing:
The First, 3D Printed Metal Bridge
Dutch company MX3D has successfully printed out a 12 m long steel bridge for pedestrians which is going to be installed in Oudezijds Achterburgwal, in Amsterdam’s infamous red light district sometime this 2019. A Robotic arm was used to print the 4-meter-wide bridge made from molten steel. Currently, the bridge is undergoing full load tests which are conducted by Arup, the lead structural engineer. The steel bridge is also equipped with sensors to gather data which will be used to create a what they term as a digital twin which will be the basis for the new design language that will run the new technique.
Europe’s First 3D House
A team in Nantes France headed by French contractor Bouygues and the University of Nantes successfully printed the first 3D house which is named the Yhnova house. The house took 54 hours to print using a patented 3D printing method called BatiPrint3D, and another 4 months for contractors to install windows, doors, and roof.
The house is equipped with sensors to monitor the quality of the air, humidity, and temperature as well as equipment to assess its thermal properties.
First 3D-printed Office in Dubai
In 2016, the first 3-D printed office was installed in the grounds of the Emirates Towers. The office was 250 sq meters in size and was made in about 17 days with the help of about only 18 people. The office was printed layer by layer using a mixture of cement and other materials. The main structure cost about £95,000 to print not including the interior and exterior design elements which were added when the structure was finished.
These are just the beginning of what 3D printing is capable of doing. And, with new materials constantly being developed, it won’t be long before we will be living and working, and maybe driving across 3D printed houses, offices, and bridges,