At the foot of Mont Blanc, in the Arve valley, in France, a first stone was laid on Friday 18 September. For the first time in the world, the company Eiffage Route and the company that manages the motorways and the Mont Blanc tunnel (Atmb) have laid an innovative asphalt that has been presented as "carbon neutral", meaning neutral in terms of greenhouse gas emissions.

Autoroutes et Tunnel du Mont Blanc @ATMBinfo

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En direct des Houches sur la #rn205 pour la pose des chaussées à empreinte carbone neutre #innovation #Environnement @eiffage @XavierRoseren

♥ 10 18 set 2020 · Apri su X →

The "green" asphalt laid on an experimental stretch of 260 metres

This is, of course, an experiment, which will need to be analysed before it can be considered a viable alternative for use anywhere. The new "green" asphalt has in fact been laid on a small section – 260 metres long and 10 metres wide – of the route nationale (national road) 205, in the direction of the well-known tourist destination Chamonix, in Haute-Savoie.

The operation was carried out as part of a road resurfacing project covering a total of 1.4 kilometres. The new asphalt features components that contain recycled materials up to 40 per cent. Meanwhile, the binder is of plant origin, based on resin, and replaces traditional bitumen, which is derived from petroleum.

Furthermore, the material does not need to be laid at particularly high temperatures, as is the case with traditional asphalt (above 100 degrees Celsius). Here it is sufficient to heat the compound to 40 degrees, which makes it possible to significantly limit energy consumption.

The material uses resin as a binder and does not require high temperatures to be laid

The "green" asphalt had already been tested for small "patches" on provincial roads, but as Eiffel Route specified in a press release, "it is the first time it has been done on a two-lane road, on which the speed limit is 90 kilometres per hour and on which 10,000 vehicles pass per day, 11 per cent of which are heavy goods vehicles. All of this, moreover, at an altitude of 930 metres above sea level, which exposes the stretch to significant temperature variations, with almost 100 days a year below zero degrees Celsius".

A monitoring programme for the new asphalt's performance is now planned, to be carried out over a period of five years. If it proves sufficiently resistant to weather conditions and traffic, it is expected to be used on other roads managed by Atmb as well.