UHPC Fiber Selection Guide: Trade-off Logic and Application Scenarios of Metallic and Non-Metallic Fibers

Fibers are the "sinews and bones" of UHPC, and the precision of fiber selection directly determines the material's toughness, durability, and application value. In the mix design of UHPC, fiber selection is one of the core decision-making steps. Based on 28 years of practical experience in architectural decorative materials, combined with application feedback from thousands of projects, Qinglong Group has developed a scientific logic for fiber selection, providing professional reference for designers and owners.

Metal fibers and non-metallic fibers (mainly polypropylene fibers, basalt fibers, etc.) are the two mainstream fiber types for UHPC. Each has its own focus in performance characteristics and applicable scenarios, and the core of the choice lies in the project's performance priorities, service environment, and cost budget. Metal fibers are dominated by steel fibers, whose greatest advantage is excellent mechanical performance—high tensile strength and good bonding with the concrete matrix—which can significantly improve the flexural strength and impact toughness of UHPC. In the public art project of the Shanghai Astronomy Museum, Qinglong selected hooked-end steel fibers to give large UHPC sculptures over 3 meters sufficient structural toughness to resist external impact and thermal stress. In addition, metal fibers offer outstanding high-temperature resistance and can retain a certain level of strength under extreme conditions such as fire, making them suitable for public buildings, industrial plants, and other projects with high fire-resistance requirements.

The core advantages of non-metallic fibers lie in corrosion resistance, lightweight properties, and construction adaptability. Polypropylene fibers are chemically stable, resistant to acids and alkalis, and anti-aging, performing better in corrosive environments such as seaside areas and chemical plants. In the UHPC supporting project of the Hainan International Convention and Exhibition Center, Qinglong selected modified polypropylene fibers to effectively resist chloride ion erosion from the marine environment, ensuring long-term stable material performance. As an inorganic non-metallic fiber, basalt fiber combines high strength with high-temperature resistance while being environmentally friendly and pollution-free, making it suitable for projects with green building material requirements. In addition, non-metallic fibers have low density, which reduces the self-weight of UHPC components and structural loads in large-span and high-rise installation projects. They also disperse better, avoiding the uneven performance caused by metal fiber agglomeration, and offer greater advantages in producing components with complex shapes. For example, the super-large translucent panels at Century Plaza on Nanjing East Road of Shanghai New World adopted non-metallic fibers to ensure the uniformity of the material's interior and its light-transmitting effect.

Fiber selection also needs to balance cost and construction technology. Metal fibers have relatively high raw material and processing costs, and their high density increases the transportation and installation costs of components. If a project does not have extreme requirements for mechanical performance, non-metallic fibers are a more cost-effective choice. From a construction perspective, metal fibers are hard and cause greater wear on mixing equipment and molds, while non-metallic fibers are soft in texture, easier to mix and disperse, and can improve production efficiency. When batch-producing standard UHPC exterior wall panels, Qinglong often uses polypropylene fibers to optimize the production process. However, in projects with strict requirements for strength and toughness, such as bridge load-bearing components and large sculptures, metal fibers remain the first choice. In the UHPC supporting project of the Shenzhen Pingshan High-tech Zone Comprehensive Service Center, Qinglong met the high flexural strength requirements of the components through precise steel fiber proportioning.

Qinglong Group's fiber selection experience stems from precise demand matching in its full-chain service. During the detailed design stage, the technical team develops a customized fiber selection plan based on the project's service environment, structural requirements, shape complexity, and cost budget; during the manufacturing stage, advanced mixing technology and quality inspection ensure that fibers are evenly dispersed in the material; during the construction and installation stage, the installation process is adjusted according to the fiber type to ensure that component performance is fully realized. As an enterprise that has participated in formulating UHPC industry standards, Qinglong will continue to track the development of fiber technology and integrate new fiber materials and application technologies into project practice.

There is no absolute answer to the choice of UHPC fibers—only the choice that best suits the project. With the mission of "creating beautiful architecture," Qinglong Group leverages 28 years of industry accumulation and professional expertise to provide scientific fiber selection recommendations for every customized project, precisely matching material performance with project needs, ensuring both the safety and durability of buildings and a balance between design creativity and cost control, and continuously setting a selection benchmark for the new architectural decorative materials industry.