The work is being carried out as part of Hanson Contracting’s pavement framework agreement with National Highways.

It is the first time Hanson has trialled its CarbonLock asphalt containing polymer-modified bitumen (PMB) bio-binders on the strategic road network.

Two trials are being carried out. The first trial includes Nynas’s biogenic binder Nypol RE and the second trial uses the same asphalt mixture but includes Shell’s new bio-component binder Cariphalte CarbonSink.

Both asphalts were produced at Hanson’s Hingston Down plant. Each trial comprised a 40mm thickness surface course with 53 PSV aggregates for around 500m of both lanes of the eastbound carriageway.

Natural biogenic material absorbs and stores carbon dioxide, which is then ‘locked’ into the bio-binders and not released back into the atmosphere, even when the asphalt is recycled.

Also the PMB binder used in both trials is expected to enhance durability and further extend the life of the asphalt.

Umesh Parajuli of the pavements team in the Safety Engineering and Standards Division, National Highways, said: “These trials are part of our feasibility study and whole-life benefits analysis of emerging low carbon technologies.

“National Highways, in partnership with Atkins, will monitor the performance of both sections and use the results of extensive laboratory testing carried out at Nottingham University to review whole-life carbon reduction with asphalt surfacing.” 

“We hope this trial containing PMB bio-binders will help to bring innovative technology into our specification.”