A first low-carbon reinforced concrete solution is tested on national highways M42 junction 6 improvement scheme.
The £282m project – designed to ease congestion for motorists at a well-known bottleneck in the Midlands – is testing the use of low-carbon concrete and basalt fiber reinforcement on a road temporary transport for construction vehicles.
The trial, conducted by Skanska, in partnership with the National Composites Center and funded by National Highways (NH), compares traditional steel-reinforced concrete to low-carbon concrete reinforced with basalt fibers.
The production of cement, a key ingredient in concrete, currently accounts for around 7% of global CO2 emissions. In the UK, this figure is below 1.5% thanks to innovation and industry investment in efficient plant, fuel switching and the use of low carbon cement substitutes which are by-products of other industries.
Tarmac, a member of the project’s supply chain, provided two types of concrete for the trial: a mix comprising a conventional blended cementitious material and an alternative low-carbon mix incorporating an alkali-activated cementitious material ( AACM) instead of cement.
Robert Gossling, Commercial Engineering Manager for Tarmac, said: “Tarmac has developed a new low carbon concrete technology and this trial is a great opportunity to work with industry leading project partners to test its performance thanks to an ideal and real application.
“Made in a conventional concrete plant located near the project and installed in exactly the same way as traditional materials, this new sustainable product offers a carbon footprint that is up to 80% lower than that of standard CEM I concrete. We hope this demonstration will help accelerate the development of innovative low-carbon materials.
Malcolm Newton, director of Basalt Technologies, explains why their basalt fiber reinforcement is being tested as an alternative to steel: “Basalt is a lightweight composite material that consumes 62% less CO2 equivalent than steel during its manufacture. . It includes an inert non-metallic material that does not corrode, making it more durable than steel. Basalt fiber reinforcement is also 4-5 times lighter than steel, making it safer to handle, repair and transport with fewer truck movements.
Glennan Blackmore, Operations Manager (Highways), Skanska UK, said: “With support and funding from client National Highways, we have been able to bring together the knowledge, skills and innovative thinking of expert teams within Skanska, the National Composites Center and supply chain partners Basalt Technologies and Tarmac to carry out this exciting trial.
“By using a unique combination of materials, we are not only working to reduce carbon, but also aim to improve the structural performance of reinforced concrete and improve productivity, safety and costs.
“This is a great example of how, working collaboratively, we can innovate to fight climate change, working towards zero carbon solutions and deliver long-term benefits to industry.
“We are delighted with the progress made to date and we are very pleased to see the results.
“The combination of low-carbon concrete and replacing steel with lightweight composite reinforcement dramatically reduces the carbon footprint by more than 50 percent.”