Colas is paving its way in low-carbon asphalt. In Reignier-Ésery (Haute-Savoie), the company specializing in public works made a clean sweep of the past by demolishing its Macamix coating site which had become obsolete, 35 years after it was commissioned. Instead, the subsidiary of the Bouygues group built, after almost a year of work, a brand new factory, inaugurated last July. Amount of investment for this cutting-edge coating station? Eight million euros.
Upon arrival, one observation is immediately obvious: no noise or dust. The ground has in fact been covered with bitumen and cladding covers the entire building. Objective: limit nuisance in order to increase the social acceptability of the 13,000 square meter site among local residents. The production capacity (80,000 tonnes per year) remains identical. “But we manufacture differently”explains to L’Usine Nouvelle Nicolas Briche, industry manager for Colas in the sector. Already, the process aims to be more virtuous in terms of energy and environment. The aggregate storage area was covered to reduce humidity and thus avoid overheating.
Also, the new calibration of the installation makes it possible to introduce up to 70% of recycled materials into the coatings compared to barely 30% previously – even if, in fact, the current average production is more around 45% taking into account restrictive criteria in the specifications of the principals. The installation also includes a recycling platform for recoverable materials, intended for both individuals and local businesses.
Diversification towards low-carbon coatings
In a large column adjoining the building, storage space with a capacity of 450 tonnes has been added. The coating produced can be kept there for a day. This avoids having to constantly produce just in time and therefore allows a wider delivery range. Finally, the site is experimenting with a closed circuit system for recovering waste heat. A first in France. “This allows us to reduce our natural gas consumption by around 10%”estimates Nicolas Briche. Beyond this less energy-intensive process, the new site also and above all makes it possible to diversify production, with ranges of asphalt with the lowest carbon impact. The old station could only produce the traditional black coating.
Macamix is now able to supply two new Colas products. The first, Urbalith, is a permeable coating which can be installed “cold”, even in Natura 2000 classified areas. The second, Vegecol, is a clear coating, in order to limit the heat island phenomenon in urban areas. , intended for pedestrian paths, cycle paths or schoolyards. Thanks to its vegetable binder and its lowered manufacturing temperature, it has a carbon footprint reduced by at least 70% compared to a traditional equivalent. “There was a real demand for this type of product but we did not know how to respond to it until now”attests Olivier Florimond, agency director at Colas. The closest factory that manufactured them was… in Saint-Étienne, more than 200 kilometers away! Enough to reduce supply circuits for construction sites in the region and further improve the environmental impact.
Source: www.usinenouvelle.com
