Since 3D printing is being used for applications in a variety of industries, how feasible is it for the construction industry? If you ask researchers at MIT, they are likely to tell you 3D printing has immense potential for the construction industry.
MIT researchers have designed a system that can 3D print the structure of an entire building. The system consists of a tracked vehicle that carries a large, industrial robotic arm with a smaller, precision-motion robotic arm at the end. This highly controllable arm can be used to direct any conventional (or unconventional) construction nozzle, such as those used for pouring concrete or spraying insulation material.
Unlike typical 3D printing systems which use some kind of enclosed, fixed structure to support their nozzles which limits the size of the objects they build, this free-moving system can construct an object of any size. As proof of concept, the researchers used a prototype to build the walls of a 50-foot-diameter, 12-foot-high dome — a project that was completed in less than 14 hours of “printing” time.
For initial tests, the system fabricated the foam-insulation framework used to form a finished concrete structure. This construction method, in which polyurethane foam molds are filled with concrete, is similar to traditional insulated concrete formwork techniques. Following this approach for their initial work, the researchers showed that the system can be easily adapted to existing building sites and equipment. It will help meet existing building codes without requiring whole new evaluations.
Ultimately, the system is intended to be self-sufficient. It is equipped with a scoop that could be used to both prepare the building surface and acquire local materials, such as dirt for a rammed-earth building, for the construction itself. The whole system could be operated electrically, even powered by solar panels. The idea is that such systems could be deployed to remote regions (e.g., the developing world) or to areas for disaster relief after a major storm or earthquake to rapidly provide durable shelter.
The creation of this system, which the researchers call a Digital Construction Platform (DCP), was motivated by the overall vision of designing buildings without parts. Such a vision includes combining “structure and skin” along with beams and windows in a single production process. It also includes adapting multiple design and construction processes on the fly as the structure is being built.
The nozzles of the new 3D printing system can be adapted to vary the density of the material being poured and even to mix different materials as it goes along. In the version used in the initial tests, the device created an insulating foam shell that would be left in place after the concrete is poured. Interior and exterior finish materials could be applied directly to that foam surface.
The system can even create complex shapes and overhangs. The team demonstrated this by including a wide, built-in bench in their prototype dome. Any needed wiring and plumbing can be inserted into the mold before the concrete is poured, providing a finished wall structure all at once. The system can also incorporate data about the site collected during the process, using built-in sensors for temperature, light and other parameters. This data allows the system to make adjustments to the structure as it is built.
MIT is not the only organization that sees 3D printing applications in the construction industry. Cazza, a construction firm based in Dubai, has announced plans to build the world’s first 3D-printed skyscraper. The company has confirmed that it will be erected in the United Arab Emirates. It says it will use a new technique called “crane printing” to create the building.
Cazza’s chief operating officer shared that the crane printing system can be easily adopted with existing cranes so that cranes do not have to be built from scratch. Cazza is adding new features to make it adaptable to high wind speeds along with the use of a layer smoothing system that creates completely flat surfaces. Because of this, you won’t know the structure is 3D printed.
3D printing presents potential advantages and disadvantages for the construction industry. The advantages include:
- Increase in speed and accuracy
- Reduction in labor costs and the amount of waste
- Creation of a safer work environment by decreasing health and safety risks
The disadvantages for the industry are:
- Elimination of jobs
- Reduction in demand for materials from traditional manufacturing companies
- Transportation and storage costs of 3D printers
As MIT and Cazza have pointed out, 3D printing does have a potential place in the construction industry. Once MIT and Cazza use more of this technology, we will see how much potential becomes reality.
(Photo: Skyscraper, Pixabay)