Case Study: Eiffage Route Developed Biophalt, a High-Performance Plant-based Asphalt, in an Effort to Decrease CO2 Emissions in Road Construction

Eiffage has created a plant-based asphalt that is made of recycled road-surfacing components (reclaimed asphalt) and a bio-sourced binder that comes from paper and forestry sector byproducts. By using this mixture, CO2 emissions related to road construction are greatly decreased.

In a bid to revolutionise road surfacing practices, the project aimed to substitute conventional bitumen-binder mixtures with a plant-based binder and recycled resources. This innovative approach sought to not only enhance the sustainability of road construction but also reduce carbon emissions associated with traditional asphalt production.

Environmental respect is a strategic priority for Eiffage Route, the road business of the Infrastructures sector of the Eiffage Group. The R&D teams at Eiffage Route, which has its own studies and research centres in Ciry-Salsogne in the Aisne region and in Corbas near Lyon, have succeeded in replacing bitumen with plant-based materials and in recycling recycled materials using plant-based binders that are not derived from oil during a time when the use of fossil fuels and fossil resources must be reduced. They have created a number of environmentally friendly blends among which is  Biophalt® – a warm asphalt mix with high-performance mechanical and environmental properties which is appropriate for all kinds of traffic, including heavy motorway traffic.

Biophalt® is more than 91% biobased and is labelled as bio-product by Karibati (label #FR/15/07/20/91). It was the winner of the Routes & Rues 2019 call for innovative projects (CIRR), driven by IDRRIM and the French Ministry of Ecological Transition and Territories Cohesion (MTECT).

A patent protects the formula for Biophalt® and the manufacturing method. The components come from the pine industry.

Made from byproducts from the French forestry and paper mills sector, it is composed with a novel plant-based binder. Thanks to a number of innovations, Biophalt® is an excellent low-carbon mix while retaining the performance of a traditional mix. Some of its benefits include:

1- A high rate (>30%) of reclaimed asphalt pavement set up from the current surface, providing surfaces created with a conventional mix with the same resistance and durability, Because the ingredients in Biophalt® are byproducts of the paper and pine industries.

2- The use of a plant-based binder with a high degree of regeneration as a 100% replacement for conventional bitumen binder.

3- Energy savings due to a lower production temperature: compared to traditional mixes, the mix is created at a temperature that is 20–30°C lower. Warm, energy-saving procedures are used in a traditional asphalt plant to produce Biophalt®. It can be used in the same applications as a traditional mix. It is prepared in a lab setting in accordance with the current performance requirements. Biophalt® has no restrictions on traffic and can be applied to a variety of granular sizes and functions as a base, binder, or surface coating. Biophalt® can be recycled in full.

A mixing process comparable to that of polymer modified bitumen is applied in the creation of Biophalt® binder. Without modifying industrial machinery, Biophalt® can be used as a traditional binder. However, the minimum temperatures for coating and spreading are marginally lower (130°C and 115°C, respectively).

The A40 motorway, which runs between Mâcon (Saône-et-Loire) and Bourg-en-Bresse (Ain), is the area where Eiffage Route is conducting the first Biophalt ® testing on a motorway surface.

Enhancements in energy efficiency: decreased energy usage as a result of using a heated asphalt mixture.

Enhancing non-energy resource efficiency: Utilising bio-sourced materials, 40% recycling of asphalt aggregates from the current road surface—a performance that permits the preservation of a substantial portion of natural resources (aggregates and binder)

Emissions absorption: carbon sink creation, negative emissions (BECCS, CCU/S, etc.): carbon can be stored in the biomass used (wood) thanks to the use of bio-sourced materials.

Attractiveness: The A40 project made it possible for APRR and Eiffage Route to collaborate on a shared objective. Due to the collaborative efforts of all these parties, this project is a successful example of a low-carbon, sustainable motorway.

Well-being: Workers on construction sites who are exposed to high temperatures during the asphalt application process experience less discomfort when warm asphalt mix is used, which has a temperature 20°C to 30°C lower than a hot mix.

Social cohesion: Since the byproducts of the paper industry, kraft paper pulp in particular, which is used to make the binder of this plant-based mix, are mainly derived from European forests, Biophalt® contributes to the development of local wood industry sectors.

Preservation and restoration of the environment: Because bio-sourced goods allow for the storage of carbon during photosynthesis, their use in the road industry helps to mitigate global warming. Therefore, through the creation of carbon sinks, a project that encourages the use of bio-sourced materials helps to limit global warming. Furthermore, Biophalt® is produced using wood that comes from sustainably managed forests, which supports biodiversity preservation. Thus, the main benefits of Biophalt® asphalt mixtures are their utilisation of renewable resources and energy savings.

Resilience: Biophalt® has been tested for resilience and submitted for approval to an independent research institute. In 2017, tests conducted at the Nantes fatigue carousel by Gustave Eiffel University proved that Biophalt® was just as durable as conventional asphalt over an extended period of time.

Responsibly managing resources: Using the Biophalt® binder relieves the strain on natural resources in a number of ways. The components of Biophalt® are byproducts of the paper and pine industries; the product is made from biosourced ingredients that do not compete with the food business. – the use of warm mixes, which enables fuel economy; – the section’s 40% recycling of aggregates from the current road surface. This performance makes it possible to preserve a sizable amount of natural resources (binder and aggregates).

ATMB and Eiffage Route are experimenting with carbon-neutral pavements for the first time on the motorway.

2050 Materials partnered up with Eiffage, a renowned leader in construction and infrastructure development. At the heart of this collaboration lies Eiffage’s groundbreaking innovation: “Biophalt” a plant-based asphalt solution engineered with a bio-sourced binder derived from forestry and paper industry by-products, coupled with recycled road-surfacing materials. This innovative asphalt mix stands as a beacon of sustainability, offering a tangible solution to reduce CO2 emissions associated with road construction. By harnessing the power of renewable resources and promoting the circular economy through material recycling, Eiffage has demonstrated its commitment to environmental stewardship and paving the way for a greener future. Through this partnership, 2050 Materials aims to amplify the impact of this eco-friendly asphalt solution, facilitating its integration into sustainable construction practices worldwide.

Learn more about Biophalt on app.2050-materials.com here and reach out to us on info@2050-materials.com for more information.

Construction 21: https://www.construction21.org/infrastructure/fr/biophalt-a-high-performance-vegetable-asphalt-coating.html

Eiffage: https://ambition4climate.com/wp-content/uploads/2021/06/Projet-Eiffage_enrobe-vegetal-hautes-performances-Biophalt-vf-EN.pdf

2050 Materials app: https://app.2050-materials.com/product/details_designer/eiffage-biophalt-bio-sourced-asphalt/