A future-proof railway system with 100% circular railway sleepers!
THIOTRACK® sleepers made of sulphur concrete give you as a railway manager greater peace of mind. Not only do these sleepers meet all the functional and technical requirements as described in the European standards and technical specifications. But the sulphur concrete also has a very low impact on both the climate and the environment.
Why choose a THIOTRACK® railway ?
A SUSTAINABLE CHOICE
100% circular
Sulphur concrete can be brought back to its liquid form by simply melting it at 135°C. This implies that the sulphur concrete of THIOTRACK® sleeper can easily be separated from its embedded components like steel. As so the concrete and all the integrated components can be endlessly reused in an identical or new concrete applications, without any loss of value or quality.
Even with the use of only primary and high-quality raw materials, we guarantee 100% circularity.
No water usage
In sulphur concrete, water and cement are replaced by sulphur. And not even a drop of water is consumed during the production process. Neither as raw material nor as process water during production (e.g. for cooling). Not insignificant, since water is becoming increasingly scarce and precious.
Long lifespan
As the sleepers do not absorb water, due to its hydrophobic characteristic, the physical, mechanical and chemical properties of the product are 100% preserved. Long lifespan is consequently guaranteed.
Low CO2-emission
The CO2 emissions of the THIOCRETE® production process are exceptionally low compared to conventional cement concrete and other commonly used materials such as steel, ceramics and plastic. There is a 50-80% reduction in emissions due to the avoidance of cement and the low-energy production process.
Harmless to the environment
Sulphur concrete contains no toxic substances and does not leach out. The various forms of elemental sulphur are also insoluble in cold and hot water. Due to its hydrophobic behaviour, sulphur is even able to bind polluting raw materials and prevent their leaching.
Find out more about our THIOTRACK® range here.
A TECHNOLOGICAL WONDER
High Strength
Vibration resistance
Hydrophobic
Thermal resistance
Combustibility
Waterproof
High strength
Sulphur concrete is a high-strength concrete that belongs to the highest strength classes on the market. It is highly resistant to alternating loads (‘fatigue’).
THIOTRACK®
This is shown by some dynamic tests carried out at the SNCF (National Railway Company of France) test centre. There, it was tested how a test piece made of sulphur concrete reacts under varying loads between 10 and 126 kN, at 5 Hz and this for 3,106 cycles. The mechanical properties remained the same after the test.
Research centre: SNCF Centre d’expertise et d’Essais PSIGT.LVE.T4 de Saint-Ouen (FR)
Tested according to: EN 13230-1/2; EN 13481-2; CT IGEV 003 E
Hydrophobic
Sulphur concrete is hydrophobic and therefore water-repellent. Water absorption fluctuates between 0.2% and 0.5%.
This is very low compared to standard cement concrete where these values are between 3 and 8%. This very low water absorption rate protects the material against the penetration of all kinds of liquids and the degradation processes that can result, such as during thaw/frost cycles. In applications where water absorption is not allowed, this material therefore comes in very handy (e.g. in counterweights for overhead lines of railway tracks).
Research centre: SGS Intron (NL)
Tested according to: NEN EN 12350-2 : 2000 (water absorption); NEN EN 1339 (thaw/frost cycles)
What is the water absorption difference between sulphur concrete and conventional concrete?
Thermal resistance
Sulphur concrete was tested for both compressive and tensile strength, dynamic e-modulus and creep (1 year), within a temperature range of 20 to 80°C. This was to check its performance when used in hot environments and contact with liquids at high temperatures, etc.
The tests show that sulphur concrete, with prolonged exposure or peak discharges up to 80°C, still retains 95% of its initial strength. Above 80°C, mechanical properties begin to decline with repeated temperature fluctuations. Occasional higher temperatures are permissible if they are short or transient in nature.
Research centre: SGS Intron (NL)
Tested according to: NEN-EN 12390-3, NEN-EN 12390-6, NEN-EN 1992-1-1
A succession of significant temperature fluctuations does not accelerate material performance degradation. This is shown by tests carried out during cycles of 150 days at temperatures between -20°C and 60°C , combined with relatively high humidity.
Combustibility
Testing performed at fire safety specialist WRF in Ghent, Belgium, shows that sulphur concrete qualifies under fire class A2. This means that the material is practically fireproof. It melts only on the surface. The underlying aggregates do not allow the hot pressure points to penetrate deeper.
Research centre: SGS Intron (NL)
Tested according to: SQD (according to Dutch Building Materials Decree)
What is the impact of a heated (280°C, 405°C and 625°C) metal object weighing 1 kg on a sulphur concrete element?
Waterproof
Sulphur concrete is hydrophobic and therefore has a very low water absorption rate (< 0.2%). This protects the material against the penetration of all kinds of liquids and the degradation processes that can result from this, such as during thawing and frost cycles. In applications where water absorption is not permitted, this is ideal (e.g. in counterweights for railway track catenaries).
Vibration resistance
Perfect resistance to vibrations
THIOCRETE® is a high-strength concrete that is highly resistant to alternating loads (‘fatigue’). This is proven by extensive tests with alternating loads on THIOTRACK® sleepers.
The SNCF test centre carried out dynamic tests to check the resistance of the sulphur concrete to changing constraints of between 10 and 126 kN, at 5 Hz and over 3,106 cycles. No deterioration in the mechanical characteristics was observed at the end of these tests.
Research centre: SNCF Centre d’Expertise et d’Essais PSIGT.LVE.T4 de Saint-Ouen (Fr)
Tested in accordance with standards: EN 13230-1/2, EN 13481-2 and CT IGEV 003 E
Frequently Asked Questions
• What’s the CO2 emission of a THIOTRACK® railway sleeper?
Due to low energy production process and the replacement of cement
by sulphur as a binding agent, the CO2 emissions of a THIOTRACK® sleeper are more than 50% lower compared to a traditional cement sleeper.
Although the energy consumption is higher in the production process of sulphur concrete, THIOCRETE® still has a significantly lower CO2 footprint due to the elimination of cement.
• How strong is a a THIOTRACK® sleeper?
THIOTRACK® fully aligns with the material characteristic requirements for railway sleepers, outlined in governmental scopes of building materials THIOTRACK® is a chemically stable sleeper, which has been exposed to various European accreditation tests from railway infrastructure managers. Through these tests, THIOTRACK® has demonstrated its outstanding performance.
• What do we mean with 100% circular?
THIOTRACK® is designed as a 100% circular material, implying that these sleepers can be fully recycled, whereas cement concrete sleepers can only be downcycled. The circularity of THIOTRACK® implies that, after a melting process, the sulphur concrete and all the integrated components can be reused into identical or new concrete elements. A sulfur concrete sleeper contains all the raw materials for the next concrete sleeper.
- Video from De Bonte Innovation
• Is THIOTRACK® a solution against the scarcity of raw materials in the future?
Yes. During its lifetime, the THIOTRACK® sleeper ensures its primary functionality but also allows storage of raw materials for the second-generation sleeper. The production process is a physical transition, allowing the process to be completely reversed through a heating process.
• Have accreditations already been obtained for THIOTRACK®?
THIOTRACK®received the technical accreditation from Infrabel in 2019 and from SNCF Réseau in 2022. In 2020, THIOTRACK® received its first orders (€13m contract Infrabel 2021-2026).
• Which products have already been developed in THIOCRETE®?
Railway sleepers and counterweights are the products that are marketed today for railway infrastructure. Also sewerage pipes in sulphur concrete ( THIOTUBE®) are developed and marketed.
We are in research and development for a multitude of other applications.
• Which types of THIOTRACK® sleepers are available?
The range of THIOTRACK® sleepers includes all different types of monobloc sleepers, twin-bloc sleepers, tramway and craneway sleepers as elements for switches. Specialties such as sleepers with under sleeper pads (called “USP’s) and sleeper with anti-friction system can be provided as so can all types of fastening systems be integrated.
• Do you want to produce THIOCRETE® yourself?
Ask us for more information about the licensing agreement. Bonte Group engineering services will guide you by transferring innovative technology worldwide.
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