Sustainable Approaches to Asphalt: Life Cycle Analysis and Innovation Opportunities in the Asphalt Industry in Norway

The construction industry is a major consumer of virgin materials that is slowly being forced to adapt as environmental regulations tighten. The asphalt industry faces urgent challenges in reducing its ecological footprint as they are a major consumer of bitumen and stone materials for road construction. Alternative materials that reduce the environmental impact and resource demand for asphalt are therefore critical for future road projects. This study explores the environmental performance of three alternative asphalt production techniques focusing on bio-based and waste materials, through a life cycle assessment (LCA) methodology. The study highlights key environmental impacts of novel asphalt materials. Mixtures incorporating 50% Silica Green Stone (SiGS), a byproduct of silicon manganese production, exhibits the highest greenhouse gas (GHG) emissions among the innovative compositions tested, primarily due to transportation distances. In contrast, asphalt using tall oil as a bio-based binder and asphalt incorporating recycled asphalt (RAP) show reductions in GHG emissions, although the latter is constrained by material availability. The findings underline the potential of combining bio-based binders, recycled content, and slag aggregates to achieve environmental benefits, such as reduced GHG emissions and virgin resource demand, provided logistical challenges are addressed.