On the E39 at Lyngdal, the foundations for future road construction are now being laid.

Every year, the production of refined manganese alloys for the global steel industry results in 220,000 tonnes of by-products at Eramet AS in Kvinesdal. Now the by-product Silica Green Stone (SIGs), which has previously been used as a filler in various contexts, is given new life as an asset in the construction of the new E39 at Lyngdal in Agder in the summer of 2024. This will potentially set a whole new standard for sustainable road construction in Norway.

“1,500 tonnes of SIGs will be used as reinforcement layers under the asphalt at a 200-metre test site,” says Øyvind Karstein Kjørkleiv, technical business developer at Eramet.

Using the large volumes of by-products from Eramet's production locally is both good for the environment and can create new business opportunities.

“It replaces crushed rock in the road body, which causes many positive ripple effects for the environment. It also saves potentially large transport costs and potentially increases value creation for Eramet,” he continues.

The reinforcement layer is now laid on a highly trafficked highway, where the bottom layers of the road construction are expected to have a lifespan of 50 to 100 years.

“We now have the opportunity to test the use of the material in practice. We have good documentation in the project that makes us confident in the result,” says Marit Flatvad, researcher at SINTEF.

“If it works here, it will work all over the place,” says Helen Roth, general manager of VIA - the transport infrastructure industry cluster. VIA has the role of project manager for the project “Sustainable value chain and material use in road construction”, of which the pilot is part.

Towards 100% circular road

This is the first time in Norway by-products from the process industry have been piloted as road material on a highly trafficked road. In order to achieve this, the Norwegian Public Roads Administration has granted waivers from some of its requirements for road construction materials. This summer, a new revision of the N200 Road Construction, a regulatory framework aimed at all those who plan, design and build roads, will be announced. Here, among other things, it opens up for more use of recycled materials and slag.

“This project is not covered by the current regulations, and it is very nice that Statens Vegvesen sees the potential in being able to test reusable materials in road construction. We should not compromise on quality, and it must have at least as long a service life as the materials used today,” says Roth of VIA.

This pilot is the first of several to test more environmentally friendly and circular materials in different parts of the roadbody.

“Through the project, new reuse materials will be tested in all parts of the road construction, including concrete and asphalt,” says Flatvad of SINTEF.

About Green Platform — Norway's largest transformation project

The pilots are part of the Green Platform project Sustainable value chain and material use in road construction. The project will develop more climate-friendly and environmentally friendly roads in Norway, and has a cost frame of NOK 123.8 million. The main goal is to help Nye Veier achieve the goal of reducing greenhouse gas emissions in road construction by 50% by 2030. The project will test innovative solutions and bring them to market.

Project partners are New Roads (project owner), Bertelsen & Garpestad, Eramet Norway, Foamrox, Future Materials Catapultsenter, Norconsult, NTNU, Roxel Infra, Rygene-Smith & Thommesen, Saferock, SINTEF, Skanska Norge, Statens vevesen, Universitetet i Agder, Velde Industri, Velde Industri and VIA — the food cluster for transport infrastructure (project manager).

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