3D printing has been one of the most revolutionary technologies of the past few decades, and it’s starting to make its mark on the construction industry as well. With the ability to print complex shapes and structures in a matter of hours, 3D printing has the potential to transform the way we build our homes, offices, and even entire cities.
3D Concrete Printing
Holcim, a Swiss cement manufacturer, has showcased its ability to print ten houses in ten weeks using a COBOD printer and TectorPrint, a proprietary material. Similarly, ICON is constructing a 100-home community in Texas, using their Vulcan printer and Lavacrete. Despite these advancements, there are reservations regarding the true cost and benefits of 3D concrete printing
Now, I have some reservations about the use of 3D concrete printing in construction. Certain companies in this space have made questionable claims and misled the public on their true cost and advantages. The use of proprietary materials, expensive set up and dismantling and dubious building science claims are a few of the things I’m concerned about. But I still believe in the value and potential of automation in the construction industry. What if we are looking at the wrong type of 3d printers? Is there a technology or machine that is superior to these liquid concrete printers, but doesn’t get as much media attention?
Hadrian X Blocklaying Machine
Fast Brick Robotics introduces Hadrian X, an innovative blocklaying machine from Australia. Unlike traditional 3D concrete printing, Hadrian X builds structural walls using rectified bricks made of lightweight aggregate concrete. The robot can lay 200 bricks per hour, significantly faster than manual labor, reducing waste and improving site safety. Their blocks are 12 times larger than standard house bricks which drastically increases the speed of construction.
These bricks are transported to the job site on the back of a truck. They are fed through a huge telescopic robotic arm that can extend 25 meters or 82 feet. A special construction adhesive that is twice as strong as mortar, is applied to the ends of the brick. With the aid of a laser tracking head, the concrete blocks are placed at a precise spot on the wall.
Mortar-Free Construction
Hadrian X’s approach eliminates the need for mortar between bricks, using construction adhesive instead. The precision-cut bricks ensure a level structure without the need for leveling, simplifying the process. This adhesive dries rapidly, boosting construction speed, and can be used with various brick materials, making it adaptable to different project requirements.
Fast Brick Robotics uses rectified bricks that are cut down to exact dimensions. They don’t need to be leveled out. You can build 10 levels by just stacking these bricks with construction adhesive. Another advantage of using adhesive is that it dries in 45 minutes as opposed to conventional mortar that takes days to dry. Buildings in areas that have high wind loads, like Florida, need extra reinforcement. In those instances, the voids can be filled with rebar and concrete.
Zero Waste
Building homes with this robot generates little to no waste. There’s no cutting on site, no silica dust and no messy job sites. The robot can accept any type of brick, as long as it is within certain dimensional constraints. It can “print” homes with blocks made of concrete, geopolymers, hardened clay, and other materials. It’s important to note that the robot only builds the interior, structural walls of buildings. Humans still need to install the windows, roofs, plaster the interior and exterior walls or even build exterior brick facades.
Gantry vs Robot Arm
There are a couple of reasons why I think the Hadrian system could be superior to the 3D printed liquid concrete system we see so often. The first is the advantage of a robot arm over a gantry system. A gantry is the frame that supports a printer head as it moves along the x, y and z axes. This frame takes time to set up, it requires solid concrete footings, it needs to be perfectly level and it uses up space on the job site.
The Hadrian robot arm arrives at the job site on the back of a truck. It doesn’t require additional concrete footings or time consuming calibration and it takes up less space on the site. The long reach of the telescopic arm guarantees more flexibility and freedom of movement. At the end of the project, it can simply be driven off the job site. There’s no dismantling needed.
Building Science Risks
Concerns exist over thermal protection and water management with traditional 3D printed concrete walls. In contrast, Hadrian X focuses solely on structural core construction, separating insulation and protective layers, addressing these building science risks effectively.
Appearance
The distinct appearance of 3D printed concrete may be a consideration, as it features microfractures, uneven lines, and rough joints. Hadrian X’s technology ensures the end result resembles a traditional house, making it more adaptable to diverse cultural and geographical settings.
Cost
Both technologies are more expensive than traditional construction because they are new, still working out the kinks and trying to scale up. Both printers require precise floor slabs with only 3mm to 5mm of variation which are a little more expensive. The custom bricks that the Hadrian robot uses are also 10% more expensive than traditional CMU blocks.
Conclusion
Fast Brick Robotics is automating the mundane, repetitive and sometimes dangerous task of building structural walls. The simplicity of their idea and well thought-out execution makes their technology so powerful. I believe 3d printed liquid concrete has a role to play in the future of construction, but I’m not sure if printing houses is the answer. Like I said in my previous videos, it seems to be a solution looking for a problem. Ultimately, both technologies are trying to address the growing problem of labor scarcity, they are trying to reduce risk of injury, make job sites safer, and help us build faster, cheaper and better. I admire the passion behind both. Let me know what you think about these two 3D printers in the comments below. Also check out my entire conversation with Mike Pivac on my podcast channel.
