Experimental Study on the Performance Properties of Bio-based Polymer Modified Binder in Surface Course Materials on the A30

In recent years, a number of innovative bio-binders have been made available in the UK, which incorporate biogenic components. These biogenic components partially replace traditional petroleum-refined bitumen in asphalt production. The introduction of these bio-binders has significant potential to decarbonise asphalt production and support the achievement of Net Zero targets within the sector. National Highways (NH) has set out an ambitious plan to achieve net zero carbon for construction and maintenance activities in its road network. As part of this plan, a surface course trial containing polymer modified (PMB) bio-binders was undertaken on the A30 on Strategic Road Network (SRN) in England. This represented the first surface course installation of PMB bio-binders on the SRN. Two Thin Surface Course Systems were installed each incorporating a different commercially available PMB bio-binder. In addition, a control section incorporating a conventional PMB was installed to enable the performance and carbon footprint to be compared. All trial sections were successfully installed in February 2023. Laboratory assessment demonstrates the trial sections with bio-binders achieve the end performance requirements for a Thin Surface Course System in the UK. The initial results indicate that the incorporation of the bio-binder has significant potential to reduce the carbon footprint of bituminous surface courses.