3D Printed Bridges: The Why, How and Real-Life Structures

The urban architecture industry has seen the rise of structures like 3D-printed bridges and walkways in recent years. Countries all over the world have even taken to using additive manufacturing to build these connecting structures.

It’s safe to say that the construction industry values the use of 3D printing or additive manufacturing because it saves a lot of production costs on material waste and allows for the use of recycled materials among other great benefits.

Note that the 3D printed bridge to be discussed in this article is not the same as a Bridge in the 3D printing process. Read on to find out how 3D printed bridges are made and the benefits of this method!

The Benefits of Additive Manufacturing in the Field of Construction

The 3D printing technology has no doubt been a great asset in the construction field. Ever since its invention, we have seen impressive structures and urban features built all around the world at faster and cheaper rates than with other traditional methods.

The possibility of real-life 3D printed bridges — from concrete to steel bridges — has been made real through 3D printing materials and printers. If you are wondering why many construction companies are now embracing the additive manufacturing method, here are some of the reasons:

• It Reduces Costs: The use of additive manufacturing or 3D printing ensures that you only use the exact amount of material needed for the production of your structures. This way, there is a reduction of excess material as well as costs. It even helps reduce labor costs since all you need for the building job is a 3D machine.
• It Helps You Build Faster: Before the invention of 3D printing technology, building architectural features was a time-consuming process. However, with additive manufacturing, there’s the possibility for a faster process. Rather than spend a few months on construction, you can spend mere hours to even get a real 3D printed bridge or 3D printed house. The process is even faster and easier when you need to make prototypes or miniatures. All you have to do is just keep at it until you have achieved your final desired shape and quality product.
• It Allows Room for Experimentation: Additive manufacturing allows you to explore new possibilities and make as many experiments as you can instead of being limited to certain techniques. Even researchers and engineers are making various experiments with this technology; finding out what larger structures are constructible, the different materials that can be used in the 3D printing process, etc. Unlike the traditional method which doesn’t give much room to explore, 3D printing allows you to do architectural experimentations and find new techniques.
• It Offers Great Custom Design Possibilities: You might want to modify your project in a way that suits your taste or enhances the project itself, and 3D printing helps you do just that. With 3D modeling software, you are given a wide berth of freedom to design and create simple or complex geometries. Also, since new 3D printing materials are being developed every day, you can branch out from concrete bridges to using steel and plastics as well.
• Risk Reduction: Unfortunately, injuries have been sustained during traditional methods of construction, and lives have also been lost. However, with additive manufacturing, health and safety risks can be reduced and this could lead to lives no longer being endangered.

How are Large-Scale and Strong Structures like 3D Printed Bridges Made?

Making large-scale structures with 3D printing has now been made possible by making use of a large-scale 3D printer. New technologies and more efficient 3D printers are being developed every day to make printing these large-scale structures in just one part reality.

The 3D printing machines possess a crane and automated arms so they are enabled to print any big project on the spot. Be it metal 3D printing, concrete 3D printing, or large-scale printers, all possibilities to create urban architecture are already being developed.

For strong structures like bridges, depending on the materials you use, the construction has to get a lot of layers and be reinforced from time to time. You also have to take the exact purpose of your project into consideration.

For example, a pedestrian bridge has to be strong and support a substantial weight; hence the need to print it with reinforced concrete or stainless steel. However, a decorative bridge can be printed with whatever material you want e.g. plastic, as long as you have the technology for it.

You can print your bridge in different parts and proceed to assemble them. Or, you can build it at once and on the spot with big 3D machines with robotic arms that enable these kinds of infrastructural constructions, from concrete to metal bridges.

Researchers of the MX3D team have even developed a robotic 3D printer that can be placed directly on the bridge they’re also working on to print it. As soon as the first part has been printed, it can be placed on the first 3D printed part of the bridge, and it will continue to build the rest of the bridge.

Real-Life Examples of 3D Printed Bridges

With the many benefits 3D printing technology offers, especially as it uses fewer materials to reduce environmental impact, it is no wonder countries and companies have been inspired to try this method.

There have been great developments as the 3D printing industry continues to soar and quite a few 3D printed bridges have been created all across the world.

• Eindhoven University of Technology’s 3D Printed Bridge (Netherlands): With roughly three months to construct, this bridge was installed in 2018 and is said to be able to handle the weight of 40 trucks. The 26-foot bridge which integrated 800 layers of concrete to attain its quality and solidity with steel wires was designed by the Eindhoven University of Technology. It is said that the steel cable is the equivalent of the reinforcement mesh used in conventional concrete. It also handles the tensile stress because concrete cannot adequately deal with it. The bridge is known to serve primarily cyclists and pedestrians.
• Tsinghua University School of Architecture’s 3D Printed Bridge (Beijing): Built 86 feet long and installed in Shanghai, this bridge is the world's longest 3D printed bridge. It was produced by an architectural team in 2019 at the University in 450 hours, using two robotic arms. While it is the longest, the bridge is not fully 3D printed like the structure underneath the concrete is metal.
• U.S Marines’ 3D Printed Bridge: Right from January 2019, the U.S Marines have aimed at 3D printing functional concrete footbridges to reduce work time. With the combination of gravel and other heavy materials, the reduction of work from six people to eventually one person will be made possible. They also plan to expand these 3D printing strategies with their investments in 3D printers.
• The Institute of Advanced Architecture of Catalonia’s 3D Printed Pedestrian Bridge (Madrid): This 12-meter-long bridge, printed in micro-refined concrete and reinforced with thermoplastic polypropylene was built in Madrid, Spain. It's a sustainable bridge with an organic design made of eight parts, its main purpose being the preservation of the natural aspect of the park.
• School of Architecture and Urban Planning of Shangai’s Tongji University’s 3D Printed Bridges (China): Two different bridges beside the entrance of the school were printed by the University. While one is a little and flat bridge (4 meters long), the other is slightly bigger with some steps (11 meters long) but both were made with 3D printed plastic. With their nice and complex structures showcasing the design possibilities offered by additive manufacturing, they were created in 360 hours with the help of 3D printing modules, robots, and drones. At the moment these bridges are only for display.
• MX3D’s 3D Printed Bridge (Amsterdam):  This 3D printed steel bridge is the largest 3D printed metal structure in the world and it was completed in October 2018. Not only does it collect data on the strain, vibration, and displacement of the structure when in use, but combined with temperature and environment, these factors can indicate the bridge's health. The bridge can also be monitored via these factors to know when it may need further inspection. The goal of this project is to expand the applications of multi-axis 3D printing, giving it a chance to re-engineer bridge building in the future. The bridge is often used by pedestrians and cyclists to cross the Oudezijds Achterburgwal canal in central Amsterdam.

Additive manufacturing/3D printing technology in the construction field has the ability to change the building process in upcoming years with its usefulness in several situations.

Thanks to the stainless steel or reinforced concrete bridges being created, 3D printing should become more common in the future.

Conclusion

The era of 3D printing technology in the field of construction and urban architecture is here and it is being embraced by the world at large. The many benefits 3D printing offers cannot be ignored and this has paved the way for even more future possibilities and opportunities for the industry. Don’t hesitate to let us know if you have questions or require more information!