3D printing is now common in industries from medicine to manufacturing, but so far, it’s been difficult to scale up 3D printing systems to meet the needs of the construction industry.
Current 3D printing systems are mostly geared for small-scale product prototyping, but there is a demand for the technology to build houses, cyclist bridges, prefabricated portions of buildings, and other construction projects.
“3D printing in construction offers a significant potential to increase efficiency in the building sector by decreasing the time to market, reducing waste, and allowing for more design freedom,” said Abdulrahman Albar, a doctoral student in electronic and computer engineering at Brunel University London. But to achieve that potential, new 3D printers must be larger, more reliable, and capable of accurately controlling the flow of materials used to make concrete.
To meet this challenge, Albar and a research team from Brunel developed a new 3D printer featuring an extruder that conveys the mortar to the nozzle during the output process and a scraper that better controls the flow of materials.
Figure 1: The 3D printer’s scraper design and hopper.
To test their 3D printer, the Brunel team printed models of a variety of computer-aided designs, starting with rectangular blocks and progressing to more complex geometric shapes. For the most part, with a few adjustments, the results matched well with the designs. As further improvements to the extrusion control are made, this printing system will be able to achieve even more geometrically accurate structures, according to the study. The system can be extended to print other materials and scaled up with slight hardware modifications, the researchers said.
Figure 2: 3D printer and control system
As of now, 3D printers, including this new one, require a robotics specialist to operate them, Albar said. One of his team’s main goals going forward is to automate the printing process so more people can be trained as operators.
“The technology is still new,” Albar said. “We expect the technology to evolve with better automation.”
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