High-Performance Fibers for UHPC: Types, Functions & Dosage Guide

Suitable for architectural engineers, structural engineers, flooring contractors, precast component manufacturers, and technicians.

Ultra-High-Performance Concrete (UHPC) delivers exceptional compressive strength, density, and long-term durability. These advanced properties are achieved not only through low water-binder ratios and optimized particle packing but also through a critical component—high-performance fibers.

In modern UHPC formulations, fibers are essential for achieving ductility, post-crack energy absorption, and long-term crack resistance. This article provides a technical comparison of fiber types, dosage guidelines, hybrid systems, and real applications using PIONEER® HPM® High-Performance Fibers.

What Makes UHPC Different from Conventional Concrete

UHPC differs fundamentally from standard concrete in terms of microstructure, mechanical properties, and failure behavior.

Strength, Density & Durability

UHPC typically reaches compressive strengths of 120–200 MPa, far beyond normal concrete. Its dense microstructure—achieved through silica fume, ultra-fine powders, and optimized gradation—delivers:

• High tensile strength

• Low porosity & permeability

• Superior freeze–thaw resistance

• Long-term durability in aggressive environments

Why UHPC Requires Dispersed Micro-Reinforcement

Even with exceptional matrix strength, UHPC is brittle without fibers. High-performance fibers provide:

• Crack bridging at micro- and nano-scales

• Ductility and flexural toughness

• Controlled crack width (<0.1 mm)

• Impact and fatigue resistance

• Post-crack load-bearing capacity

This is why UHPC always incorporates a fiber system—typically PVA, PAN, basalt, carbon, or steel fibers.

Types of High-Performance Fibers for UHPC

PIONEER® HPM® fibers are engineered for high-strength cementitious composites. Each fiber contributes unique mechanical and durability benefits.

PVA Fibers for UHPC (HPM® PVA)

PVA fibers offer exceptional bonding due to their hydrophilic surface.

Key features:

• High tensile strength (800–1600 MPa)

• Excellent crack control

• Strong chemical resistance

• Ideal for architectural UHPC, panels, overlays, repair mortars

PAN Fibers for UHPC (HPM® PAN)

PAN (polyacrylonitrile) fibers improve both tensile and flexural performance.

Benefits include:

• High modulus and chemical stability

• Enhanced early-age cracking resistance

• Suitable for industrial UHPC, tunnel linings, and marine structures

Basalt Fibers for UHPC (HPM® Basalt)

Basalt fibers provide natural high-temperature and corrosion resistance.

Advantages:

• High thermal stability

• Good toughness improvement

• Suitable for bridge decks, precast segments, and infrastructure

Carbon Fibers for UHPC (HPM® Carbon)

Carbon fibers deliver the highest strength and stiffness among synthetic fibers.

Key benefits:

• Ultra-high tensile strength

• Superior fatigue and impact resistance

• Lightweight reinforcement

• Used in high-performance structures, precast UHPC components

Fiber Dosage Recommendations for UHPC Mix Design

Typical UHPC formulations use 1–3% fiber volume fraction, depending on the mechanical requirements.

Fiber Type	Recommended Dosage (kg/m³)
PVA	10–20 kg/m³
PAN	6–12 kg/m³
Basalt	10–25 kg/m³
Carbon	4–10 kg/m³

Notes:

• Higher dosages increase toughness but may affect workability.

• UHPC with higher aspect-ratio fibers may require superplasticizer adjustment.

When to Use Hybrid Fiber Systems

Hybrid reinforcement combines micro and macro functions:

• Microfiber (PVA/PAN): controls early-age microcracks

• Basalt or Carbon fibers: increase flexural strength and post-crack toughness

Hybrid systems are recommended for:

• UHPC overlays

• Structural retrofitting

• Prefab UHPC panels

• High-impact industrial flooring

Real UHPC Applications Using HP Fibers

High-performance fibers are widely used in UHPC projects:

• Bridge deck panels strengthened with carbon fibers

• UHPC façade cladding using PVA fibers for enhanced ductility

• Tunnel segments reinforced with PAN/basalt fibers to resist thermal and chemical attack

• Marine structures requiring anti-corrosion UHPC mixes

PIONEER® HPM® High-Performance Fibers are used in major infrastructure, including highways, marine structures, and precast UHPC components around the world.