Introduction
In modern civil engineering, tunnel segments, track slabs, and large concrete components demand materials with exceptional crack resistance, durability, and construction efficiency. High-strength macro synthetic fiber and UHPC-specific modified synthetic fiber are ideal choices, widely used in tunnel linings, high-speed rail track slabs, and large bridge components. This article explores our high-strength macro synthetic fiber (tensile strength >580 MPa, elastic modulus >10 GPa) and its combined use with modified fibers, supported by experimental results, highlighting superior performance and the unique advantage of non-abrasive properties to mixing equipment, offering an efficient solution for the concrete reinforcement fiber market.
1. Performance Advantages of High-Strength Macro Synthetic FiberHigh-strength macro synthetic fiber, made from polypropylene (PP), is engineered for tunnel segments, track slabs, and large concrete components. Its key performance attributes include:
Tensile Strength >580 MPa: Delivers superior tensile capacity, enhancing concrete crack resistance and reducing micro-crack propagation.
Elastic Modulus >10 GPa: Improves concrete toughness, withstanding dynamic loads (e.g., vibrations in high-speed rail track slabs).
Elongation at Break <8%: Ensures fiber stability under high stress, extending component lifespan.
Corrosion Resistance: Resists acid and alkali corrosion, ideal for coastal tunnels and humid environments (e.g., metro tunnel segments).
3D Dispersion: Distributes uniformly in the concrete matrix, enhancing three-dimensional load-bearing capacity, outperforming steel fibers.
When blended with UHPC-specific modified synthetic fiber, a proprietary surface treatment enhances bonding with ultra-high-performance concrete (UHPC), perfect for high-strength components (e.g., UHPC bridge panels). A typical mix ratio (60-80% high-strength fiber, 20-40% modified fiber) can be tailored to project needs, maximizing crack-resistant fiber performance.
2. Experimental Results Validate PerformanceTo verify the effectiveness of high-strength synthetic fiber and UHPC modified fiber in tunnel segments, track slabs, and large concrete components, we conducted extensive laboratory and field tests, with results as follows:
Crack Resistance Test (ASTM C1609)
Adding 1.5% (by volume) high-strength macro synthetic fiber to C50 concrete (common for tunnel segments) reduced crack width by 60% and increased crack resistance strength by 45%, outperforming steel fibers (same dosage) by 30% in crack control. Incorporating 20% UHPC modified fiber further improved crack resistance by 10%, ideal for UHPC components like track slabs.
Durability Test (EN 14651)
In simulated coastal metro environments, high-strength fibers showed superior corrosion resistance, with no performance degradation after 28-day salt spray tests, unlike steel fibers. UHPC components (with modified fibers) exhibited <5% strength loss after 300 freeze-thaw cycles, ensuring long-term stability for tunnel engineering fiber.
Dynamic Load Test (High-Speed Rail Track Slabs)
In CRTS III track slabs, a mix of 1% high-strength fiber and 0.5% modified fiber improved fatigue resistance by 35% and reduced vibration-induced cracks by 50%, meeting high-frequency dynamic load requirements for high-speed rail.
Construction Performance
Fibers dispersed uniformly, extending mixing time by only 10% without increasing pumping resistance, ensuring high construction efficiency. Tests confirmed the fibers’ smooth surface does not abrade mixers or pumping equipment, extending equipment lifespan by over 20% and reducing maintenance costs.
3. Non-Abrasive Advantage for EquipmentUnlike steel fibers, which cause wear on mixers and pumping pipes due to high hardness, our high-strength macro synthetic fiber and UHPC modified fiber use flexible polypropylene with a smooth surface (Mohs hardness <3), ensuring non-abrasive properties. Laboratory tests demonstrated:
After 100 hours of continuous mixing, mixer blade wear was <0.5%, compared to 5-8% for steel fibers.
Pumping tests (1000 m³ of concrete) showed no visible scratches on pipe interiors, with stable pumping pressure, extending equipment lifespan.
Additionally, the lightweight fibers (density ~0.91 g/cm³) reduce transportation and storage costs. When mixed, the modified fiber’s surface treatment enhances bonding without compromising equipment compatibility, making our concrete reinforcement fiber ideal for tunnel segments, track slabs, and large concrete components.
4. Application Scenarios and Real-World CasesOur high-strength macro synthetic fiber and UHPC modified fiber excel in the following applications:
Tunnel Segments: In metro tunnels (e.g., São Paulo Metro Line 6, Mumbai Metro Line 3), fibers improve crack resistance by 30% and extend service life to 100 years.
Track Slabs: In high-speed rail CRTS III track slabs (e.g., China’s Beijing-Shanghai High-Speed Railway), fibers enhance fatigue resistance, reducing vibration cracks for reliable performance.
Large Concrete Components: In UHPC bridge panels (e.g., a UAE sea-crossing bridge), mixed fibers increase tensile strength by 20%, enabling thinner designs and reducing self-weight by 15%.
Case Study: A Chinese high-speed rail project used a blend of 1.2% high-strength fiber and 0.3% modified fiber, improving track slab crack resistance by 40%, boosting construction efficiency by 10%, and cutting equipment maintenance costs by 20%. These results position our crack-resistant fiber as a top choice for tunnel engineering and municipal projects.
5. Why Choose Our Synthetic Fibers?
Superior Performance: Tensile strength >580 MPa, elastic modulus >10 GPa, elongation at break <8%, surpassing steel fibers.
Eco-Friendly and Cost-Effective: Recycled fibers (>400 MPa, >5 GPa) meet green building standards, costing 20-30% less than steel fibers.
Equipment-Friendly: Non-abrasive to mixers and pumps, reducing maintenance costs and extending equipment life.
Customizable: Blends of high-strength and UHPC modified fibers tailored to project needs (e.g., tunnels, bridges).
Technical Support: Free sample testing (5kg minimum), mix design optimization, and construction guidance ensure optimal concrete reinforcement fiber performance
Conclusion
High-strength macro synthetic fiber and UHPC-specific modified synthetic fiber are the optimal reinforcement materials for tunnel segments, track slabs, and large concrete components. With exceptional tensile strength (>580 MPa), elastic modulus (>10 GPa), and corrosion resistance, validated by rigorous testing, they meet the demands of tunnel engineering, high-speed rail, and UHPC bridges. Their non-abrasive design reduces equipment wear, lowering construction costs, while eco-friendly recycled fibers support sustainable projects. Our technical support, including samples and construction guidance, ensures maximum concrete reinforcement performance. Choose our crack-resistant fibers for safer, more durable engineering solutions.