| dc.description.abstract | Abstract
The Dutch road construction sector is seeking environmental impact reduction for asphalt and in
particularly asphalt binders. Within the CIRCUROAD project, three prototype circular and bio-based
asphalt binders were developed. In addition to laboratory and real world testing, this study aimed to
contribute by assessing the environmental impact of circular and bio-based asphalt binders compared
to conventional bitumen-based asphalt binders. The employed research method was a Life Cycle
Assessment, specifically an attributional one. The system boundaries are limited to the cradle-to-gate
boundaries with a temporal scope of 2025 – 2030. The Functional Unit is defined as follows: the
production of 1 kilogram of circular and bio-based asphalt binder for application in top layer asphalt
for the Dutch road construction sector. For eight potential asphalt binder components, coming from for
example pulp and paper industry, post-consumer waste plastic and fossil origin, Life Cycle Assessment
inventory data was modelled using the Simapro software. Inventory data was sourced both directly from
component suppliers and from scientific literature. The impact assessment was performed using impact
categories aligned with standardized methods according to the Bepalingsmethode for the Dutch
construction sector. Regarding biogenic carbon storage, the study acknowledges the lack of evidence
for long-term carbon sequestration in circular and bio-based binders, thus presenting results both with
and without consideration of biogenic carbon storage. Finally, the Environmental Cost Indicator (MKI)
scores were also calculated based on the impact assessment results.
The findings reveal that the Global Warming Potential of circular and bio-based binder
materials varies depending on their origin, with bio-based materials generally exhibiting lower
greenhouse gas emissions compared to fossil-based counterparts. The Environmental Cost Indicator
scores indicate that circular and bio-based binders generally have comparable or slightly higher
environmental impacts compared to conventional bitumen binders. However, when considering
biogenic carbon storage, the environmental impact of circular and bio-based binders can be reduced.
An additional finding is the large contribution of fossil based compatibilizers to the environmental
impact of circular and bio-based binders, identifying potential for further environmental impact
reduction.
In conclusion, the study underscores the importance of considering environmental impacts in
the selection of asphalt binder components, with circular and bio-based options showing promise for
reducing environmental burdens, especially when accounting for biogenic carbon storage. These
findings contribute valuable insights to the ongoing efforts towards sustainable road development in the
construction sector. | |
