An article on FMS Blog in February discussed the first 3D printed bridge that was produced in Madrid, Spain. Fast forward a few months and yet more exciting news has come from the 3D printing world, only this time it is from the Netherlands.
Researchers at the Eindhoven University of Technology have begun to print the very first 3D printed bridge that is made from reinforced, pre-stressed concrete. Unlike the bridge in Madrid, which was designed for pedestrians, this bridge has been designed with cycling in mind.
It is to be part of a new section of ring road around Gemert, which has been created using special and innovative techniques by the BAM Infra construction company. 3D printing a bridge is understandably a very innovative way to construct and the new cycling bridge is sure to bring attention.
Why 3D Print A Bridge?
It may be that you query why a bridge is being 3D printed instead of using traditional methods, but as the press release from Eindhoven University notes, there are advantages to this. A 3D printed bridge uses less concrete than the conventional method that requires a mold to be filled.
It goes on to state that this is actually an advantage as CO2 is released in the production of cement and there is less needed when using printed concrete. Not only is this a positive for building, but there can also be potential environmental benefits to this. As well as this, the obvious benefit to printing cement is that you are able to print whatever shape is required with no wooden molding frames required, reducing the amount of time spent.
Researchers in the group of Theo Salet, the professor of concrete construction, have also succeeded in reducing time further by developing a way to print the steel reinforcement at the same time. This is done by laying a strip of concrete while also adding a steel cable, ensuring that the bridge is ‘pre-stressed‘. What this means is that there no tensile stress can occur; something that concrete cannot cope with properly.
Bridging The Way In Gemert
A scale model of 1:2 was created and tested to ensure it is safe in recent months, allowing the researchers to adequately prove the safety of their bridge construct. The next few months will see the concrete elements printed and glued together to form the bridge itself.
It will then be put into place in September by BAM Construction Company in Noord-Om, making yet another step forward for the innovative and practical uses of 3D printing.