HS2 London tunnels contractor Skanska Costain Strabag JV (SCS JV) is to pioneer the on-site of 3D printing of graphene-reinforced concrete. The technology, called ‘Printfrastructure’, promises to bring big environmental benefits and cost savings, if deployed more widely.
First proof of concept trials are scheduled to begin in the spring, using 5 tonne computer-operated robots. These will initially be used to build part of the retaining walls for the mainline out of Euston station as well as materials stores on the project.
Reinforced concrete structures will be printed with internal lattice strengthening, significantly reducing the quantity of concrete required as well as cutting waste.
In a further big advance, steel reinforcement will be replaced by microscopic strands of graphene running through it like stripes in a stick of rock.
Replacing rebar should help to improved site safety, offer greater construction flexibility and shorter build time.
By removing steel and simplifying the construction process, which will no longer require cranes and fewer delivery trucks, the carbon reduction could be significant.
SCS JV estimates that the process it is developing with ChangeMaker 3D and materials specialist Versarien will reduce concrete used and contribute toward reducing carbon by up to 50%.
If trials are successful, 3D printing could be used for multiple structures including bridge parapets, staircases, walls, columns and station platform segments.
SCS JV Temporary Works Manager, Andrew Duck, said: Automation enabled by Printfrastructure’s 3D reinforced concrete printing creates a factory-like environmental that delivers a high-quality product that both increases efficient use of materials, and reduces our carbon footprint. It is important that we give technologies such as Printfrastructure the opportunity to flourish because of the possibilities it offers the industry to make a step change in how projects are delivered.