Dutch officials in the city of Gemert recently opened what is being called the world's first 3D-printed concrete bridge. Although it is intended primarily to be used by cyclists, the 26’ bridge has been tested to bear loads of up to five tons.
Although the bridge, which connects two roads over a flooded gully, is not very long or wide, the composition and the means by which it was constructed makes it unique. Construction took about three months to complete with the laying out of over 800 layers of printed, pre-stressed, reinforced concrete.
Officials feel the most significant advantage was that very little material was wasted in forming the bridge, and the lack of construction equipment meant fewer emissions were released into the environment. As opposed to manually dumping concrete into pre-made forms, the printer directly deposited the material where it was needed as it followed the overall design. The result was a bicycle bridge with sufficient strength to handle the weight of 40 trucks but using less concrete used than would have been previously demanded.
The Netherlands is among the leaders in global 3D printing adoption. One Dutch start-up called MX3D has even begun printing a stainless-steel bridge. It is about one-third of the way constructed with an opening scheduled for next June.