When Selecting Fibers for UHPC, How to Choose Between Metallic and Non-Metallic Fibers? Reinforcement Mechanisms and Qinglong Group Fiber Selection Guide

Selecting fibers for UHPC requires comprehensive consideration of strength requirements, durability needs, cost factors, and the application environment. Metal fibers (mainly steel fibers) and non-metal fibers (PVA, PP, basalt fibers, etc.) each have their own advantages. Based on 28 years of research in fiber reinforcement technology, Qinglong Group has summarized the selection principles: for structural components with extremely high strength requirements, steel fibers are preferred; for scenarios requiring corrosion resistance and electromagnetic insulation, non-metal fibers are chosen. In the Wuhan Hanxiu Theater project, we used copper-plated steel fibers (tensile strength ≥2500MPa), achieving a UHPC flexural strength of 22MPa; in the coastal environment of the Hainan Convention and Exhibition Center, PVA fibers were selected, improving corrosion resistance by more than 30%.

Steel fibers provide optimal mechanical reinforcement. Their elastic modulus (200GPa) matches concrete well, and their significant bridging effect can raise UHPC flexural strength to over 25MPa. We prefer hooked-end steel fibers with a diameter of 0.2mm and a length of 13mm, with bond strength to the matrix of ≥8MPa. However, steel fibers have a high density (7.8g/cm³) and are prone to rusting, so durability needs to be improved through copper plating or stainless steel materials.

Non-metal fibers perform excellently in special environments. PVA fibers have an elastic modulus of 25-40GPa and strong alkali resistance, making them suitable for coastal projects; PP fibers resist chemical corrosion but have a lower modulus (3-5GPa); basalt fibers offer good temperature resistance but at a higher price. Through fiber hybrid technology, such as combining steel fibers with PVA fibers, Qinglong Group achieves a balance between strength and toughness.

Fiber selection should be based on specific needs. For load-bearing structures, we recommend steel fibers as the primary choice; for decorative components, non-metal fibers can be selected to reduce weight; for electromagnetic-sensitive locations, non-metal fibers are essential. Scientific fiber selection is the key to unleashing UHPC performance.