Eiffage has developed a plant-based asphalt composed of a bio-sourced binder (derived from by-products of the forestry and paper industry) and recycled road-surfacing materials. The use of this mix significantly reduces CO2 emissions linked to road construction activities.
Replace traditional mixes made from bitumen binders by a mix that uses a plant-based binder and recycled road-surfacing materials.
Eiffage Route, the road subsidiary of the Eiffage Group’s Infrastructures division, attaches strategic importance to respect for the environment.
At a time when the use of fossil fuels and fossil resources must be reduced, 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 substituting plant-based materials for bitumen and in regenerating recycled materials using plant-based binders that are not derived from oil.
They have developed several eco-responsible mixes. Biophalt® is one of these. It is a high-performance plant-based mix with a resistance that makes it suitable for all types of traffic, including heavy motorway. Carrying the Bio-sourced label, Biophalt® is a winner of the Routes & Rues 2019 call for innovation projects (CIRR) issued by IDRRIM and the French Ministry of Ecological Transition and Solidarity (MTES).
Biophalt® is a warm asphalt mix with high-performance mechanical and environmental properties.
It is formulated using a new generation of plant-based binder derived from by-products of the French forestry industry.
While maintaining the performance of a conventional mix, Biophalt® is an optimum low-carbon mix thanks to a combination of several innovations:
- a high rate of recovery (≥ 30%) of aggregates planed from the existing surface, offering the same level of resistance and durability as surfaces made with a conventional mix,
- the use of a plant-based binder offering a high level of regeneration, as a 100% substitute for conventional bitumen binder (the use of bio-sourced materials does not compete with the food industry, the constituents of Biophalt® being by-products of the pine and paper industries),
- energy savings thanks to a lower production temperature: the mix is produced at a 20°C to 30°C lower temperature than conventional mixes.
Biophalt® is produced in a conventional asphalt plant using a warm, energy-efficient process. It has the same range of application as a conventional mix. It is formulated in the laboratory in compliance with the performance standards in force.
Biophalt® can be used as a base, as a binder or as a surface coating, with no limits in terms of traffic and for a range of granular sizes.
Biophalt® is 100% recyclable.
The Biophalt® formula and the manufacturing process are protected by a patent. The components are derived from the pine industry and in particular from pitch, a residue from the distillation of tall oil, which is not widely used in industry today.
Production and application
The production of Biophalt® binder uses a mixing process similar to that of polymer bitumen.
Biophalt® can be used as a classic binder without the need to adapt industrial equipment. The minimum coating and spreading temperatures are however slightly lower (130°C and 115°C respectively) Eiffage Route is carrying out the first Biophalt ® trials on a motorway surface - in this case, a section of the A40 motorway between Mâcon (Saône-et-Loire) and Bourg-en-Bresse (Ain).
Direct emissions generated by the company's activity.
Indirect emissions associated with the company's electricity and heat consumption.
Emissions induced (upstream or downstream) by the company's activities, products and/or services in its value chain.
Carbon sinks creation, (BECCS, CCU/S, …)
Emissions avoided by the activities, products and/or services in charge of the project, or by the financing of emission reduction projects.
- Production: +35.5 tCO2eq.
- Freight entering the site: +10.4 tCO2eq.
- Application: +16.8 tCO2eq.
- Freight leaving the site: +10.3 tCO2eq.
= total scope 1:73 tCO2eq.
- Extraction of materials: -80.4 tCO2eq.
- Transport Upstream: 2.5 tCO2eq
Emission removal - The bio-sourced binder stores carbon during the growth phase of the material (pine trees) it is composed of
- -87 teq CO2
The construction of 1 linear kilometre of motorway lanes using conventional asphalt requires 1021 tonnes of asphalt.
For 1021 tonnes of conventional asphalt, the following is required:
- 44 tonnes of bitumen
- 597 167 MJ of gaz for heating (170°C)
- 817 tonnes of non-recycled road-surfacing materials (representing 80% of total requirements, the rest from recycling)
For more information, download the complete project sheet
The A40 project enabled APRR, Eiffage Route and the Epsilon design office to join forces around a common goal. The synergies provided by each of these different stakeholders have made this project an effective low-carbon and sustainable motorway demonstrator.
The Biophalt® binder eliminates bitumen fumes and therefore improves air quality around work sites for residents and site workers alike. In addition, the use of a warm asphalt mix, with a temperature 20°C to 30°C lower than a hot mix, reduces discomfort for workers on construction sites, who are subjected to high temperatures during the asphalt application process.
Biophalt® helps to develop French wood industry sectors, since the by-products generated by the paper industry, the manufacture of kraft paper pulp in particular, used to manufacture the binder of this plant-based mix come from French forests.
Environmental preservation / enhancement
The use of bio-sourced products in the road industry contributes to limiting global warming because they allow carbon storage during photosynthesis.
Consequently, a project promoting the use of bio-sourced materials contributes to limiting global warming by creating carbon sinks. In addition, the forests from which the wood for the production of Biophalt® is obtained are sustainably managed, which promotes the preservation of biodiversity.
Therefore, the use of renewable resources and energy savings are the major advantages of Biophalt® asphalt mixes.
Biophalt® has been submitted for the approval of an independent research institute to test its resilience: tests carried out by the Gustave Eiffel University at the Nantes fatigue carousel in 2017, established that Biophalt® was equally or even more durable over time than a conventional asphalt.
Responsible use of resources
The use of the Biophalt® binder allows a reduction in pressure on natural resources in several ways:
– the use of bio-sourced materials that do not compete with the food industry, the constituents of Biophalt® being by-products of the pine and paper industry,
– the use of warm mixes allowing a reduction in fuel consumption,
– 40% recycling in the section of aggregates from the existing road surface. This performance allows a significant quantity of natural resources (aggregates and binder) to be preserved.
The project is intended to be reproduced for several similar operations, the interest project owners are showing in low-carbon solutions will enable Biophalt® to be industrialised on a larger scale. In addition, this binder can be used for a variety of road types – ranging from light to heavy traffic.
Studies on the binder’s resilience and low-carbon advantages were carried out jointly by Eiffage Route and the University of Nottingham as part of the BioRepavation project.
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