In the field of road construction materials, the research inspired by green chemistry focuses on two cornerstones.
The first is recycling.
As part of a circular economy approach, Colas reuses increasing quantities of reclaimed asphalt pavement in its asphalt mixes, thus reducing the need to use new materials, be it the aggregates used in the asphalt mix or the binder. Other recycled raw materials are also used locally depending on availability and performance.
The second area of research focuses on the use of bio-based raw materials.
Bio-based raw materials come mainly from the "wood" and "oleaginous" sectors. Through photosynthesis, CO2 carbon is stored throughout the product's life cycle, achieving the goal of carbon neutrality.
Plant chemistry is also a source of innovation and contributes to generating added value in terms of performance. Worthy of note are:
- EKOFLUX® and VEGEFLUX® bioflux agents, with very good solvent and fluidizing characteristics that make it possible to replace petroleum fluxes;
- COLQUICK storable cold mix, whose binder is partially bio-based, is reactive with water and provides very quick coalescing on contact with it; this product has a better resistance to traffic than existing solutions;
- aesthetic plant-based binders which are transparent, thus making it possible to enhance the natural color of the aggregates, or obtain brightly colored coatings by adding pigments. These binders are particularly suitable for architectural or ornamental environments, where aesthetics is a priority. Their use is also recommended for making light-colored mixes that contribute to the fight against urban heat islands.
It should be noted that Colas was the first to introduce a mix using a bio-based binder called VEGECOL® in 2003.