HS2 to employ innovative 3D printing process

HS2 Ltd said the development represented “a major step forward in construction technology”. Called ‘Printfrastructure’, the process is scheduled for first deployment in 2022 by HS2 Ltd’s London tunnels contractor SCS JV (Skanska Costain Strabag Joint Venture). At first it will be used to build sections of retaining wall for the mainline out of Euston station as well as for materials stores on the project. But it could later be applied to bridge parapets, staircases, walls, columns and station platform segments.

The computer-controlled printing creates reinforced concrete structures with a strengthening internal lattice structure said to significantly reduce the quantity of concrete used and to cut waste. The Printfrastructure process combines 3D concrete printing with graphene – one atom thick, the thinnest material known to man and around 200 times stronger than steel. Concrete is reinforced not with steel but with microscopic strands of the material to help drive improved site safety, greater construction flexibility, shorter build time and a smaller carbon footprint.

Furthermore, printing concrete with the five-tonne computer-operated robots will enable SCS JV to create structures on site, instead of transporting them by road as pre-cast sections, and having to assemble and lower them into place by large cranes. Therefore fewer trucks on the road and fewer cranes will be needed.

The technique is suited for use in confined working areas, avoiding the need, it is claimed, to develop complicated and potentially expensive logistical plans. Beside a live railway, the robot can print the reinforced concrete but still allow construction to continue and importantly, for trains to run without disruption.

Changemaker 3D – SCS JV’s Worcestershire-based partner – developed the technology in association with UK advanced materials specialist Versarien.