A cycle path has been built in Birmingham using a new type of low-carbon asphalt.
Jackson Civil Engineering brought together two suppliers, one with a carbon negative aggregate and one with a cold foamed bitumen asphalt, to generate CO2 savings of up to 90% compared with a traditional hot AC20 asphalt mix.
The mix was used in the construction of a new cycle path being built for Birmingham City Council as part of the Bromford flood alleviation scheme. Andy Lusher, Jackson supply chain manager said: “The cycle path provided an opportunity to look at the original design and ask ourselves how we could do this in a more carbon-friendly way. We brought our supply chain together to use their expertise and came up with a solution that was truly innovative”.
Partners in the trial scheme include OCO Technology, which has developed a carbon negative aggregate made from waste material for the treatment of flue gases from waste incinerators. OCO technical director, Stephen Roscoe said: “With Zero Carbon being a global target, the construction industry must source alternative, more sustainable products, to not only reduce the carbon footprint but to preserve the finite reserves of national aggregate in the UK.
Surfacing specialist Toppesfield was also central to the project. Its team took the eco product and mixed it with ToppFoam, its own cold foamed bitumen asphalt that incorporates recycled aggregates.
Paul Phillips, Toppesfield technical director said: “Working on the Bromford project has given us an opportunity to look at where we can further reduce carbon in our operations. Our strength and resilience tests show the new cold foam mix is fit for purpose and as we strive towards Net Zero, we expect it to become the surface mix of choice for future path and light road construction projects”.
Phase 1 of the 2.5km cycle path has been built and work on the remainder is expected to start in April. It is projected that up to 70 tonnes of CO2 could be saved on its entire construction.
A further 30 tonnes of CO2 was saved using Cemfree concrete to bed and surround the kerb stones along the path. This product was developed by DB Group and produced by Accumix Concrete.
Tony Sheridan, DB Group commercial manager, said: “This project is another example of the market-driven demand for real world applications of sustainable construction products as the general public’s concerns over carbon emission and climate change are felt”.
Andy Lusher said that this trial had given Jackson confidence to specify low-carbon concrete and asphalt in future projects. “We’ve learnt lessons from this trial and we no we can do something that pushes the boundaries, but only with the full support and buy-in from our supply chain partners”.