In a major underground mining project in northern Europe, engineers faced a persistent challenge: traditional steel friction bolts were corroding rapidly in the highly acidic groundwater, leading to premature support failure and costly rehabilitation. The solution came from SupAnchor, a global leader in geotechnical reinforcement systems, which deployed its newly patented SupFRP® GFRP friction bolt. This world-first innovation offers a lightweight, corrosion-resistant, and non-conductive alternative to steel friction bolts, setting a new benchmark for underground support in aggressive environments.
The SupFRP® GFRP friction bolt is engineered to complement SupAnchor’s broader portfolio, including the self drilling anchor system and hollow bar anchor solutions, providing a complete drill-and-grout bolt package for challenging ground conditions. As infrastructure projects worldwide demand longer service life and lower maintenance, this GFRP-based product marks a significant step forward in geotechnical safety and efficiency.
At the heart of the GFRP friction bolt’s performance is its unique material composition. Unlike conventional steel friction bolts, which are prone to corrosion and spark generation, the SupFRP® bolt uses glass fiber reinforced polymer (GFRP) to deliver exceptional durability and safety. During installation, the bolt is driven into a slightly smaller borehole, creating a frictional grip along its entire length that provides immediate support to the surrounding rock mass. This process requires no resin or cement grout, making it fast and efficient for tunnelling and mining crews.
Key technical advantages of the SupFRP® GFRP friction bolt include:
The table below compares critical properties of steel and GFRP friction bolts, highlighting the performance leap achieved by SupAnchor’s innovation.
| Property | Steel Friction Bolt | GFRP Friction Bolt |
|---|---|---|
| Corrosion resistance | Low | High |
| Density (g/cm³) | 7.8 | 2.0 |
| Coefficient of heat conductivity at 20℃ (w/m) | 64 | 0.75 |
| Electroconductibility | Yes | No |
| Tensile elongation (GPa) | 200 | 55 |
| Tensile strength (N/mm²) | 390 | 1000 |
| Working temperature | < 1000 ℃ | -50 ℃ - 100 ℃ |
The FB-48 model, one of the standard configurations, has an outside diameter of 50 mm, an ultimate load capacity of 350 kN, an end load of 70 kN, and weighs only 1.7 kg/m. These specifications ensure that the bolt can withstand high ground pressures while remaining easy to handle.
| Parameter | Value |
|---|---|
| Outside Diameter | 50 mm |
| Bolt Ultimate load | 350 kN |
| End Load | 70 kN |
| Weight | 1.7 kg/m |
The high tensile strength of 1000 N/mm²—more than double that of typical steel bolts—combined with excellent corrosion resistance, makes the SupFRP® GFRP friction bolt an ideal choice for long-term support in aggressive environments. Its low thermal conductivity (0.75 w/m vs 64 w/m for steel) also prevents heat transfer, which can be critical in temperature-sensitive underground spaces. 
The SupFRP® GFRP friction bolt is designed for a wide range of underground and surface applications. In mining, it proves invaluable in ore passes, drawpoints, and development headings where corrosion and ore contamination are major concerns. Because the bolt can be easily cut and crushed, it does not damage crushers or conveyors, and its low density allows simple separation during beneficiation. This reduces downtime and prevents costly equipment repairs, making it a favorite among mining engineers.
In tunnelling and civil engineering, the bolt excels in projects with high groundwater salinity, such as subsea tunnels or coastal infrastructure. Its non-conductive nature eliminates the risk of stray current corrosion, which can rapidly degrade steel support systems near electrified railways or utilities. Furthermore, the bolt’s light weight reduces manual handling strain and speeds up installation, which is particularly beneficial in confined spaces or remote sites with limited lifting equipment.
The GFRP friction bolt also integrates seamlessly with SupAnchor’s self drilling anchor bolt and drill-and-grout bolt technologies. Where ground conditions are fractured or unstable, contractors can use a self drilling anchor system to create the borehole and install a hollow bar anchor for immediate grouting, followed by the GFRP friction bolt for supplementary frictional support. This combined approach provides a complete geotechnical reinforcement system tailored to the most demanding rock mass conditions.
However, the working temperature range of -50℃ to 100℃ limits its use in high-temperature applications such as deep geothermal wells or areas with extremely high ambient heat, where steel may still be preferred. Nonetheless, for the vast majority of underground mining and civil projects, the GFRP friction bolt offers unmatched performance.
Global investment in underground infrastructure continues to grow, driven by urbanization, mining expansion, and renewable energy storage projects. According to industry analysts, the demand for advanced ground support products is expected to rise significantly over the next decade. In this context, the SupFRP® GFRP friction bolt addresses a critical gap: the need for durable, low-maintenance support systems that reduce lifecycle costs and improve safety.
Traditional steel friction bolts often require replacement or supplementary support after 5–10 years in corrosive environments, leading to high maintenance costs and operational disruptions. The GFRP friction bolt, with its inherent corrosion resistance, can extend the service life of ground support by several decades, translating into substantial savings for mine operators and infrastructure owners. Moreover, the bolt’s non-sparking and non-conductive properties align with stricter safety regulations in mining and tunnelling, reducing liability and insurance costs.
SupAnchor’s commitment to innovation is evident in its robust R&D pipeline and adherence to international quality standards. The company’s manufacturing facilities are certified to ISO 9001 and other relevant standards, ensuring consistent product quality and traceability. With a global distribution network, SupAnchor has supplied its geotechnical reinforcement systems—including self drilling anchor system, hollow bar anchor, and drill-and-grout bolt products—to major projects across Europe, North America, South America, and Asia-Pacific. The introduction of the GFRP friction bolt further solidifies SupAnchor’s position as a professional, innovative, and collaborative partner in ground engineering.
As the industry moves toward more sustainable and resilient construction practices, materials like GFRP are poised to become the new standard. SupAnchor’s SupFRP® GFRP friction bolt is not just a product; it is a testament to the company’s forward-thinking approach to solving the toughest geotechnical challenges. With this launch, SupAnchor reinforces its brand promise of delivering reliable, high-performance support solutions that meet the evolving needs of modern engineering.
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