The LIAISON project is helping to make Europe’s transport systems more sustainable. A new study by project partner Slovenian National Building and Civil Engineering Institute shows how giving railway tracks a “rubber boost” could make them last longer and reduce waste.
Railway ballast – the layer of crushed stones beneath the tracks – plays a vital role in keeping trains running smoothly and safely. Over time, ballast breaks down under the heavy loads of passing trains, which means it needs to be replaced. The research looked at whether adding small amounts of recycled tire material could make reused ballast stronger and more durable.
Small change, big potential
The study, Deformation Properties and Performance Evaluation of Reused Ballast with Waste Tire-Derived Aggregates, investigated how material from end-of-life tires can be used to strengthen reused ballast. The findings suggest a practical solution that could extend track life and reduce maintenance costs for rail operators.
The team tested ballast mixes containing 0%, 5% and 10% of tire-derived aggregates (TDA) – basically shredded pieces of old tires. They then measured how each mix performed under conditions similar to those railways face in real life.
What they found:
- Strength: Adding 5% TDA made almost no difference to strength compared with standard ballast. But adding 10% led to a bigger drop in strength.
- Resilience: With 5% TDA, the ballast was better at absorbing and withstanding the pressure of passing trains.
- Durability: The ballast with 5% TDA broke down less and showed lower wear and tear, making it likely to last longer.
The conclusion? 5% recycled tire content is the “sweet spot” – giving ballast better performance without weakening it.
Read the full results in the open access paper
Why this matters for the transport sector
- Cutting waste: Old tires that often end up in landfills could be reused in railway construction.
- Saving money and resources: Stronger ballast means tracks need less frequent maintenance and replacement.
- Ready to apply: The tests used practical materials and methods, making this approach realistic for future railway projects.
Next steps
The next stage of the LIAISON project will look at testing this method on real railway tracks, along with studying costs and regulations. If successful, this simple idea could make railways both greener and more reliable.
By reusing waste and improving infrastructure at the same time, LIAISON partners are showing how small changes can deliver big benefits for Europe’s transport future.
