When Selecting Fibers for UHPC: How to Choose Between Metallic and Non-Metallic Fibers — A Comprehensive Consideration of Performance, Cost, and Application Scenarios

Amid the wave of innovation in building materials, ultra-high performance concrete (UHPC), with its outstanding mechanical properties and durability, is becoming the “star material” for landmark buildings and high-end venues. As a key reinforcing component of UHPC, the choice of fiber directly affects material performance, engineering costs, and service life. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group will analyze the scientific trade-offs between metallic and non-metallic fibers for designers and owners from three dimensions—performance matching, cost optimization, and scenario adaptation—helping projects achieve a triple balance of “technology, economy, and aesthetics.”

1. Performance Trade-offs: The Strength Advantages of Metallic Fibers and the Functional Properties of Non-metallic Fibers

Metallic fibers (such as steel fibers and stainless steel fibers), with their high elastic modulus and excellent interfacial bonding, have become the “core players” in enhancing the compressive and flexural strength of UHPC. In scenarios with stringent mechanical requirements, such as bridge structures and heavy-load floors, metallic fibers can increase the flexural toughness of UHPC by 3-5 times and extend fatigue life to more than 10 times that of ordinary concrete. The General Technical Conditions for Non-Load-Bearing Ultra-High Performance Concrete (UHPC) Components, whose development Qinglong Group participated in, clearly states that in components subjected to dynamic loads, the incorporation of metallic fibers can effectively inhibit crack propagation.

Non-metallic fibers (such as polypropylene fibers and basalt fibers) open up differentiated application space with their lightweight, corrosion-resistant, and alkali-resistant properties. The high-temperature resistance of basalt fibers makes them suitable for building components in high-temperature environments, while the low elastic modulus of polypropylene fibers provides early-age crack resistance in concrete—especially in the thin-walled forms of GRC decorative components, reducing surface cracking caused by drying shrinkage. In the Nanjing East Road Century Plaza renovation project, Qinglong successfully achieved unsupported 30-meter-span installation of translucent UHPC components by incorporating modified polypropylene fibers.

2. Cost Balance: Economic Considerations of Short-term Investment vs. Full Life-Cycle Costs

The material cost of metallic fibers is typically 3-5 times that of non-metallic fibers, but their dosage per unit volume is only 1/10 that of non-metallic fibers, narrowing the overall cost difference to 1.5-2 times. For large municipal projects such as metro utility tunnels and airport runways, metallic fiber UHPC, with its longer service life (over 100 years), actually has lower full life-cycle costs. In a bridge project in Malaysia, Qinglong used stainless steel fiber UHPC to replace traditional reinforced concrete; although the initial cost increased by 15%, maintenance costs dropped by 60%, saving nearly 30% in total cost over a 20-year period.

Non-metallic fibers are better suited for cost-sensitive commercial decoration projects. Taking GRG ceilings as an example, incorporating glass fibers can reduce material costs by 20% while meeting interior decoration requirements for fire protection (Class A non-combustible) and sound insulation (NRC≥0.8). For the custom GRC facade panels Qinglong produced for the Dongguan Women and Children's Activity Center, optimizing the basalt fiber dosage achieved a 12% reduction in cost per unit volume while ensuring flexural strength of ≥15MPa.

3. Scenario Adaptation: Precise Matching from Engineering Requirements to Aesthetic Expression

In structural load-bearing applications, metallic fibers remain the first choice. In a river-crossing bridge UHPC deck project Qinglong helped build, ultra-fine steel fibers with a diameter of 0.2mm were used, reducing component thickness by 40% and self-weight by 35%, while meeting the requirement of 3 million cycles of fatigue load testing. In decorative components, non-metallic fibers demonstrate unique advantages: GRP daylighting canopies reinforced with glass fibers can achieve curved forms with light transmittance above 85%; UHPC art sculptures incorporating colored carbon fibers ensure strength while presenting delicate textural qualities.

For overseas projects, environmental adaptability becomes a key consideration. In a high-temperature, high-salinity project in Saudi Arabia, Qinglong used alkali-resistant glass fiber reinforced UHPC, whose chloride ion penetration coefficient is 2 orders of magnitude lower than that of ordinary steel fibers, ensuring 20 years of maintenance-free service. In cold Nordic regions, the low-temperature impact resistance of basalt fibers is more advantageous, with impact toughness at -40℃ 25% higher than that of steel fibers.

There is no absolute “optimal solution” in fiber selection, only the “most suitable solution.” As a national Specialized, Refined, Distinctive, and Innovative enterprise and a participant in industry standard development, Qinglong Group consistently relies on its full-chain service capabilities (detailed design-production and manufacturing-construction and installation-after-sales maintenance) to provide customers with integrated solutions from material selection to project implementation. Whether for bridge projects pursuing ultimate strength or landmark buildings shaping artistic forms, Qinglong leverages 28 years of technical expertise to precisely match UHPC's performance potential with project requirements, ultimately fulfilling its brand mission of “creating beautiful architecture.” Choosing Qinglong means choosing not just materials, but a commitment to engineering quality and long-term value.