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New Railway Track Sleeper Made from Recycled Materials with Improved Mechanical and Acoustic Properties
New Railway Track Sleeper Made from Recycled Materials with Improved Mechanical and Acoustic Properties
Development of the CIRTRACK Railway Track Structure: Enhancing Mechanical and Acoustic Performance through the Reuse of Recycled Materials in Line with Circular Economy Principles
As part of the LIAISON project under the Horizon Europe programme, co-funded by the European Union, a test section was established near the Divača railway station to evaluate the performance of the newly developed CIRTRACK railway track structure. The solution incorporates a novel ballast element manufactured from reused materials, designed to reduce noise and vibrations.
The LIAISON project develops knowledge and technological solutions aimed at reducing the environmental impacts of transport infrastructure throughout its entire life cycle—from construction and operation to decommissioning. The project's objectives include reducing material and energy consumption, lowering emissions and carbon footprint, optimizing energy management, and decreasing the life-cycle costs of transport infrastructure. One of the solutions developed within the project is the improved railway track structure featuring a new ballast element, which has been tested on the demonstration section near Divača.
Prometni institut Ljubljana Ltd. participated in the project by documenting and testing the new railway track structure and by facilitating access to the railway infrastructure required for the implementation of the DEMO 3 test site. The project was also supported by the Slovenian Infrastructure Agency.
CIRTRACK
Project partner ZAG developed the innovative CIRTRACK railway track structure, which incorporates ballast containing recycled rubber from end-of-life tyres and lateral concrete retaining elements connected by a geogrid.
The solution is designed to reduce vibrations and noise while improving the durability of railway infrastructure through the use of circular materials. Prior to the construction of the test section, extensive laboratory investigations were carried out to determine the optimal composition of the track structure and to verify the physical and mechanical properties of the new solution.
Testing of the Improved CIRTRACK Railway Track Structure
DEMO 3 represents a test section established to evaluate the performance of the innovative railway track structure incorporating ballast enhanced with recycled rubber particles, together with lateral concrete elements and a geogrid.
Prometni institut Ljubljana participated in the selection of the test location and carried out the contractor selection procedure for the construction of the 60-metre-long test track. One half of the track was constructed using the CIRTRACK system, while the other half was built as a conventional railway track structure to enable comparative measurements. Following construction, measurements of stresses, vibrations, and displacements were carried out during the passage of a two-way rail vehicle.
The test section consists of two interconnected 30-metre segments. The first segment incorporates reused ballast with recycled rubber additives and lateral concrete elements, while the second serves as a reference section featuring a conventional railway track structure. The same base ballast material was used in both sections to ensure comparable testing conditions.
The test section was constructed in May 2026 on the abandoned railway line between Divača and Rodik. Monitoring of settlement, displacements, and vibrations was carried out on 25 May 2026 in cooperation with ZAG. During multiple passages of a two-way rail vehicle, the measurement system collected data on the performance of both railway track structures.
Although the test section was not intended for regular railway traffic, it represents the first implementation of the CIRTRACK solution in a real-world environment.
Findings
The purpose of the test section was to compare stresses, vibrations, and displacements in the newly developed CIRTRACK railway track structure with those observed in a standard railway track structure. The results of laboratory and field measurements confirmed the advantages of using recycled rubber, a geogrid, and lateral concrete elements.
The optimal composition was found to be a mixture containing 5% rubber aggregate from end-of-life tyres. This composition improves the mechanical properties of the track structure, enhances vibration damping, and extends the service life of the ballast. The environmental impacts are negligible, and the addition of rubber does not compromise fire safety. Measurements showed an approximately 50% reduction in vibrations, as well as reduced ballast wear and breakage, enabling up to 30% lower maintenance costs.
A significant effect was also demonstrated by the system of lateral concrete elements combined with a geogrid, which limits the lateral spreading of the track structure, reduces deformation, and improves its stability under traffic loads. Compared with a conventional railway track structure, the system resulted in approximately 50% lower permanent deformation and improved resistance to vertical and horizontal loads.
The results confirm that the combination of reused ballast, recycled rubber, a geogrid, and concrete elements effectively enhances vibration damping and structural stability. The test section demonstrated that the key objectives of the CIRTRACK solution were achieved: at least 80% reuse of materials, a 50% reduction in ground vibrations, and improved mechanical properties of the railway track structure. The obtained results provide an important basis for further development and future implementation of this solution in railway infrastructure.