Researchers at the University of Cambridge, UK, developed the first 3D printed piece of concrete infrastructure used on a National Highways project.

The structure is a type of retaining wall known as a headwall and has been installed on the A30 in Cornwall. These types of walls are normally made in limited shapes from precast concrete, requiring formwork and extensive steel reinforcement.

However, by using 3D printing, the researchers could more freely design the shape and constructed a hollow wall with no formwork or steel reinforcement. The wall gets its strength from its geometry instead. It measures two metres by three and a half metres and took one hour to print.

In the concrete, sensors are embedded. These provide up-to-date measurements including temperature, strain and pressure, which could help spot and correct faults before they occur. The wall functions as a laboratory, generating data over its lifespan and helping to understand how 3D printing can be used and tailored in infrastructure projects.

Photo: University of Cambridge