Challenge

Road construction demands significant quantities of raw materials and energy, creating GHG emissions from extraction through manufacturing, use, maintenance, and end of life. In Europe, where 20.5 million tons of bitumen are consumed annually, with 85% allocated to paving, bitumen represents a major driver of embodied asphalt emissions despite making up a small percentage of total mix mass. Updated lifecycle datasets have heightened transparency around these upstream impacts: Eurobitumen’s lifecycle assessments (LCA) 4.0 reports a global warming potential (GWP) of 530 kg CO₂e per ton of refined bitumen, up from 216 kg CO₂e/t in earlier models, largely due to better accounting of methane emissions in crude oil supply chains. Concurrently, evolving environmental regulations and standards (such as ISO 21930 and EN 15804+A2) require lifecycle-based assessments, accelerating market demand for bio-based binders that lower carbon intensity.

Innovation

Tall oil pitch (TOP) PN (pitch, neutral) is derived from crude tall oil refining and acts as a bio-based extender to replace a portion of petroleum bitumen in paving and roofing formulations. By incorporating TOP PN, manufacturers can reduce the cradle-to-gate product carbon footprint of the binder, particularly when biogenic carbon accounting is applied.  

Beyond carbon reductions, TOP PN can enhance functional performance, particularly low-temperature cracking resistance. When optimized for specific application demands,
substitution rates of up to 20% can achieve performance comparable to traditional paving formulations. This drop-in approach enables gradual adoption of bio-based solutions
within existing paving applications while supporting long-term decarbonization goals. 

Key Findings

Laboratory evaluations indicate that optimized TOP PN blends can maintain standard paving performance while enhancing low-temperature cracking resistance. These findings are supported by European pilot road sections, which demonstrate that properly formulated bio-extended binders can perform under real-world traffic loading and climate conditions. Adoption is also being encouraged through procurement programs, including Norwegian public road tenders that prioritize lower-carbon asphalt solutions. At the same time, national research initiatives such as CIRCUROAD in the Netherlands and ADEPT Live Labs 2 in the United Kingdom continue evaluating bio-based binders for broader infrastructure applications.