SGL Carbon’s fibres strengthen an awarded German bridge

The German Steel Construction Engineering Award, given every 2 years by the bauforumstahl e.V., rewards outstanding structures and innovative bridge constructions. The road bridge BW 399c, located along the A3 highway near Nuremberg, Germany, has been awarded by this prestigious prize. The 64-metre-long road bridge is made with carbon reinforcement based on 50k Sigrafil^® carbon fibres developed by SGL Carbon. Designed by Leonhardt, Andrä und Partner, it stands out because it is the first road bridge in Europe to add carbon reinforcement to a composite roadway slab which is orthotropic, i.e. whose material properties differ along 3 orthogonal axes. This innovation has enabled less concrete to be used in its construction.

The pioneering use of carbon fibre-reinforcement

One of the main advantages of this innovative bridge is its sustainability. If we compare its CO₂ balance with that of conventional steel composite structures, the building of the BW 399c road bridge saved more than 60 t of CO₂ thanks to the mix of concrete with carbon fibre.

As well as reducing emissions, the use of carbon reduced the weight of the bridge: the roadway slab weighed 55% less, or 450 kg/m². This lightness did not make the bridge any less solid; carbon is in fact a highly corrosion-resistant material, which also makes the bridge more durable.

What is more, the way the bridge was built created less inconvenience to local residents: the reduced weight and prefabrication of the bridge segments enabled it to be installed overnight.

“This project combines several innovative approaches and demonstrates impressively how the use of modern materials such as carbon reinforcement can revolutionise bridge construction in the long term,” concludes Tobias Mansperger, project manager and authorised signatory at the engineering company Leonhardt Andrä und Partner, which designed the bridge.

Could this pioneering use of carbon fibre contribute to an increase in demand for this composite material? Indeed, the 9 months of fiscal year 2024 show a decline in SGL Carbon’s sales due to the weak demand for carbon fibres.

A weak demand in the wind and automotive industries

According to preliminary figures, SGL Carbon’s group sales for the first 9 months of the fiscal year 2024 decreased by 4.8% year on year to €781.9 million (US$841.2 million), compared with €821.7 million (US$884.0 million) over the same period in 2023. This is due to the current weakness in demand for carbon and textile fibre products, which affected the carbon fibre business unit and, combined with the early termination of a customer contract in the composite solutions business unit, caused the decrease of the group’s sales.

SGL Carbon’s carbon fibres business unit manufactures carbon and textile fibres for the wind and automotive industries as well as for a variety of industrial applications. However, demand for carbon fibres in these sectors is weak, increasing competition and pressure on prices.

 The group does not expect demand and prices for these materials to increase over the coming year and is therefore revising its medium-term planning for carbon fibres.

An event-driven impairment test currently carried out for this business unit indicates that a non-cash impairment charge of €60–80 million (US$64.5 million-86.1 million) will be recorded in the fourth quarter of 2024. SGL Carbon’s equity ratio after the impairment is estimated at 40%.

However, the other business units are performing well. As a result, the preliminary adjusted EBITDA remained at a comparable level to the prior-year period, at €127.6 million (US$137.4 million), compared with €130 million (US$139.9 million) over the same period in 2023, while the adjusted EBITDA margin improved to 16.3% after 9 months in 2024 (9M 2023: 15.8%).

Cover photo: Road bridge BW 399c with Sigrafil^® fibre from SGL Carbon