Pioneering 3D printing helps build UK road

Costain has led the use of 3D printing in a UK road-building project for the first time. 

The A30 scheme for National Highways used the 3D printing of concrete instead of pre-casting the material offsite.  

The 3D printing technique was used to help build a structure known as a ‘headwall’ for a wildlife corridor on the A30 Chiverton to Carland scheme. 

These wildlife crossing points will support otters, badgers and reptiles making their way from one side of the A30 to the other. 

The 33 wildlife crossing points are part of a sustainable approach to widening the nine mile stretch of the A30 into a dual carriageway. 

Together with traditional Cornish Hedges, which support a variety of flora and fauna, the scheme is expected to drive a 20% net gain in biodiversity. 

The 3D printing allows shapes to be made which are difficult or impossible with traditional techniques. 

The project, supported by specialist partner Versarien, has used curved headwalls which are stronger than traditional rectangular headwalls and so don’t need steel reinforcement in the walls, allowing steel to be removed from this part of the construction.  

Bhavika Ramrakhyani, head of materials at Costain, explained: “This is a really exciting project that could transform the future of infrastructure. 3D printing has the potential to make construction cheaper, quicker and more sustainable. 

“As we push towards net zero, it’s vital that the UK makes use of these emerging technologies.” 

A headwall was chosen for the trial because of the ease of access for installation and monitoring, but the technology could be expanded to other areas once proved successful. 

Data will be gathered over a six-month period by researchers from Cambridge University to evaluate the performance of the technology and support its wider application within the construction industry.   

Joanna White, National Highways’ roads development director, said: “We’re committed to exploring sustainable and innovative ways of constructing and maintaining our roads and this marks a significant first step as part of the work carried out by the Roads Research Alliance. 

“It’s a collective effort, we’re pleased to be partnering with the university and Costain, and through our collaborative funding and research, we look forward to realising and delivering further initiatives within the highways industry. 

“Together we are developing ideas that will improve how we design, maintain, operate and build roads as well as increase safety on our network. This is the first time National Highways has formed an alliance like this to deliver research, and we look forward to seeing the exciting results.” 

Costain brought existing experience to the project, having previously used 3D printing to install the first 3D printed concrete chamber in the UK water sector. 

The wastewater chamber significantly reduced the carbon, cost and time of the project. Costain has also introduced 3D printing for some concrete elements of HS2.