In the Algete workshops, north of Madrid, the remains of a crushed wind blade await their second life. For years he captured the wind in a park in Cadiz; Today it is part of an experimental concrete slab.
Spain is finding an unusual way to unite two environmental challenges: the recycling of thousands of wind blades that accumulate as waste and the urgency of reducing the carbon footprint of concrete, one of the most polluting materials on the planet.
From the blades to the ground. Acciona and Holcim have developed successfully a new sustainable concrete made from recycled wind turbine blades. The project, named Blade2Buildis part of a European innovation initiative in the circular economy.
The prototype consists of a slab of more than 120 square meters built in the Demoparque of the Acciona Technology Center, in Algete (Madrid). As the company explainsthe composition incorporates materials from wind turbine blades in fiber form as a partial replacement for natural aggregates. In other words, crushed shovels are used to replace some of the gravel or sand normally used in concrete.
The mix. The base of the new concrete is an ecological version developed by Holcima type of material designed to minimize its environmental impact. In this case, the formula includes 11% recycled components, including fibers from crushed wind blades. This technology, known as ECOCycle, allows you to reuse materials that would otherwise end up as waste, without compromising the strength or durability of the product.
A low CO₂ emission cement is also used, manufactured with less clinker —the substance obtained by heating limestone to more than 1,400 °C and which is mainly responsible for the emissions of traditional cement. According to Holcim This combination reduces the carbon footprint of the final product by almost half. In addition, the glass fibers and resins of the blades act as internal reinforcement, improving the material’s resistance to traction and fractures. The energy that once moved with the wind now settles in the earth.
The dilemma of the shovels. In the coming years, thousands of wind blades will stop spinning in Europe. Silent, gigantic, they will remain on dry land after two decades facing the wind. It is calculated which will be about 14,000an avalanche of materials—fiberglass, carbon and resins—that will add up to between 40,000 and 60,000 tons of waste. They are made to last, not to disappear. And that is the great dilemma: their resistance, the same that made them useful, now condemns them.
In the United States, the consequences of not planning the end of the cycle have already been seen: in 2020, an aerial photo of a landfill in Wyoming, taken by Bloombergshowed hundreds of half-buried wind blades. The scene went viral and served as a warning to Europe, which is now working on solutions that allow its materials to be recovered instead of burying them.
¿Does it really work? The first trials are promising. According to Holcimthe resulting concrete maintains the necessary structural properties and meets durability standards. The shredded blade fibers not only reinforce the material, but also improve its flexibility and resistance to fracture.
It is not the only case. The University of Burgos has been experimenting with its own method for several years, based on the use of TPA (Wind Turbine Blade Grinding), a material obtained by cutting and grinding the blades into tiny fragments. The Sustainable Construction Research group (Sucons) has even paved a 50-meter street on the Milanera campus with this type of concrete.
But it is not Acciona’s first project. As part of the #TurbineMade initiative, one of the blades in the Tahivilla park in Cadiz was transformed into a limited series of sports shoes manufactured together with the El Ganso brand. As explained by the companythose recycled soles symbolize their commitment to achieving 100% sustainable materials in their collections.
The paradox is unique. The same materials that once helped produce clean energy can now be used to reduce emissions from the most polluting industry. If concrete was the material of the 20th century, perhaps the material of the 21st is the one that manages to build without destroying. And in Spain, at least, they have already begun to do so. Shovel by shovel.
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