The numbers behind carbon in asphalt
These figures are indicative estimates that vary by scope and year.
Where carbon fits in asphalt
In-scope carbons have a modest but growing presence in asphalt modification. Graphene nanoplatelets and graphene oxide are added to bitumen binders to raise stiffness, reduce rutting and delay fatigue cracking. Lab studies report a 20 to 40 percent improvement in complex shear modulus at graphene loadings of just 0.1 to 1 percent by weight.
Biochar is being evaluated as a bitumen modifier and partial aggregate substitute, pairing performance benefits with carbon-sequestration credentials. Pilot roads in Europe and North America have run since 2023, with Verde BioAsphalt among the first commercial projects. Carbon nanotubes improve binder cohesion and fatigue life at loadings below 1 percent by weight.
The dominant carbon additive in asphalt by volume is carbon black, used as a UV stabiliser in modified bitumen membranes, which sits outside ACC's scope. ACC tracks where the in-scope materials are being trialled, the producers behind them and the evidence base, so members can see where adoption is real and where it remains early.
Key carbons used in asphalt
Drawn from materials ACC has linked to asphalt coverage and producers. Each links to its full material profile.
