For the first time in the UK, on-site 3D reinforced concrete printing is set to be used to significantly simplify the build programme on parts of the HS2 project, bringing with it environmental, cost and community benefits.
The cutting-edge ‘Printfrastructure’ technology will be deployed by HS2 Ltd’s contractor for its London tunnels, SCS JV (Skanska Costain STRABAG Joint Venture) and represents a significant step forward in UK construction technology.
The first test deployments, as part of a range of proof-of-concept trials, are planned for early 2022.
Printing concrete in this new manner, using computer-operated robots, will enable SCS JV to make structures on site, instead of transporting them as pre-cast slabs by road before being assembled and lowered into place by large cranes.
As flexible mobile technology, 3D concrete printing enables the technique to be deployed in physically restricted areas – avoiding the need to develop complicated and potentially expensive logistical plans.
In particular, where construction on HS2 is occurring alongside a live railway, it presents an opportunity to deliver works without disrupting existing services on the nearby live route.
This is possible because the technology allows a robot to print the reinforced concrete, enabling construction to continue and trains to run at the same time safely. Previously, similar work would have had to take place overnight after train services had stopped running, potentially disturbing local residents, or would have required the temporary suspension of services to ensure safe working conditions.
The use of a computer-controlled robot also enables the reinforced concrete structures to be printed with a strengthening unique internal lattice structure, which not only significantly reduces the quantity of concrete required, but also cuts waste.
Further benefitting the process, SCS JV’s Worcestershire-based partner, ChangeMaker 3D, has worked with UK advanced materials specialist, Versarien, to develop the technology and introduce into the 3D concrete printing process strands of graphene – the strongest material ever tested.
Concrete with microscopic strands of graphene, only several atoms thick, running through it in stripes replaces traditional steel to help drive improve site safety, greater construction flexibility, shorter build time and a smaller carbon footprint.
Estimates from SCS JV suggest that the new technology could reduce the concrete use and contribute toward reducing carbon across the project by up to 50%. Removing steel and simplifying the construction process, which would no longer require cranes and significantly fewer delivery trucks, could further support carbon reduction too.
HS2 innovation manager Rob Cairns said: “The project SCS JV and ChangeMaker 3D are collaborating on is a fantastic demonstration of the kind of far-reaching innovations HS2 enables. With a build programme spanning the decade and across the country, the project is creating an ideal environment to develop technologies with the potential to transform how major infrastructure is built.”
SCS JV Temporary Works Manager, Andrew Duck, added: “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.”