Improper curing can lead to delays in builds being completed and can even make structures prone to damage and collapsing.
Enter the concrete-printing robot. Mechanical arms swing back and forth, programmed not to collide, mixing and pouring concrete into large-scale structures. The robot’s optimisation means that the mix is blended evenly to ensure consistency and for a faster curing time, speeding up the strengthening process.
In 2018, a team of researchers at Nanyang Technological University (NTU) in Singapore, led by Pham Quang Cuong, an associate professor at the School of Mechanical and Aerospace Engineering, achieved just this.
Using two robotic arms, the NTU researchers were able to print a concrete structure measuring 1.86m by 0.46m by 0.13m in just eight minutes. The structure took two days to harden and a full week to reach its full strength – in standard industrial cases, concrete can take up to 28 days to achieve its maximum strength, although this isn’t a hard-and-fast rule.
According to Pham, the ability to use 3D-printing dexterous robots could give architecture and construction companies the option to pour more complex designs.
The NTU team haven’t been the only people innovating in this area – Netherlands-based CyBe and Swiss firm Sika are specialists in 3D concrete printing. But the NTU’s invention is smaller and lighter, which would make it easier to transport if the technology were ever to be scaled up.
“We imagine it could be used in a situation where the robots are transported to a construction site, deployed to print the concrete structure that is needed and then they’re transported onto the next site,” said Pham, who is also the founder of an NTU spin-out, Eureka Robotics.
The construction industry is notoriously slow when it comes to embracing and implementing innovations. The reason being, said Andreas Velling, a mechanical engineer at sheet-metal fabrication company Fractory, is that construction sites are full of people, moving objects and heavy machinery, which makes testing technology tricky.
“Any new technology usually requires a controlled environment. A construction site is pretty much as far from this definition as you can go,” added Velling.
The industry has also long been seen as one of the slowest to adopt digitisation, preferring instead to rely on paper-based processes and work off paper-based blueprints.
One study, by KPMG, found that two-thirds of 200-plus construction and engineering executives surveyed don’t use advanced data analytics to inform their decision-making. Only one in five said they were actively thinking about implementing new technologies into their business.
If the construction industry is to benefit from advances in robotics, then the change arguably needs to start at the top. “It all comes down to the potential cost savings,” said Velling. “Companies also need to be able to implement any technologies in working conditions without having to shut down heavy machinery or ask builders to slow down so robots can work around them.”
In time, Velling expects that robots will become commonplace on construction sites, just like autonomous processes have in factories – they will be relied on to carry out tasks such as bricklaying and other masonry work. He adds that the construction sector can look to the manufacturing sector as an example of how robotic technology can help to improve productivity and efficiency.
The ultimate question is whether robots could be used to print houses on a commercial and wide scale. Technically it’s possible, and has been demonstrated before, but it’ll only catch on if prototypes prove that construction companies will be able to lower building costs without compromising the integrity or design of a structure, argued Velling.
One area where printed concrete houses may become extremely beneficial is in providing accommodation for people left homeless following a humanitarian crisis or natural disaster. A current relief shelter is typically either a tent or hut made from wood and corrugated iron.
Construction start-up Icon, of Austin, Texas, has developed a method for printing a single-storey concrete house, measuring 60m2, in the space of 12 to 24 hours. Its ambition is to make housing more accessible and it unveiled its first community of printed houses, in Tabasco, Mexico, last year.
Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.