Macro Synthetic Fiber Reinforced Concrete (MSFRC): Definition, Benefits, Standards

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

Macro Synthetic Fiber Reinforced Concrete (MSFRC) has become a widely adopted solution in industrial flooring, precast products, shotcrete, pavements, and tunneling applications. By incorporating high-strength macro synthetic fibers—typically 30–65 mm in length—MSFRC provides enhanced toughness, impact resistance, and a safer, corrosion-free alternative to steel mesh or steel fibers. As construction demands move toward durability, resilience, and lower maintenance costs, MSFRC is now a preferred reinforcement technology for many concrete systems.

What Is MSFRC?

MSFRC is fiber-reinforced concrete that uses structural-grade macro synthetic fibers to improve post-crack load capacity and energy absorption. Compared with microfibers, which mainly control plastic shrinkage cracking, macro synthetic fibers contribute directly to the structural behavior of concrete.

Macro synthetic fibers are typically manufactured from polypropylene, polyolefin blends, or engineered copolymers, and are designed with surface embossing, twisting, or fibrillation to improve mechanical anchorage.

Key Benefits of MSFRC

• Replaces steel mesh in slabs-on-ground

• Enhances toughness and ductility

• Improves impact and fatigue resistance

• Excellent corrosion and chemical resistance

• Reduces labor and installation time

• Minimizes shrinkage-related cracking

• Safer to handle than steel fibers

• Maintains long-term durability in harsh environments

MSFRC is especially beneficial in applications requiring distributed 3D reinforcement, such as warehouses, pavements, industrial floors, tunnels, slopes, shotcrete, and precast structures.

Applicable Standards

To ensure reliable performance, MSFRC materials and concrete mixes are evaluated using internationally recognized standards.

EN 14889 (Europe)

EN 14889 defines performance criteria for synthetic fibers used in concrete.For MSFRC, relevant requirements typically include:

• Tensile strength

• Modulus of elasticity

• Anchorage performance

• Durability tests (alkali resistance)

• Fiber geometry and classification

The fibers must meet Category II (structural fibers) to be used as primary reinforcement in structural concrete and shotcrete.

ASTM C1116 (United States)

ASTM C1116 is the primary American standard covering fiber-reinforced concrete.For MSFRC, the standard outlines:

• Fiber classification and physical properties

• Required performance in fresh and hardened states

• Compliance for structural reinforcement use

• Minimum requirements for distribution and bonding

Concrete reinforced with macro synthetic fibers must demonstrate consistent performance in post-crack load capacity and energy absorption.

Performance Requirements

The engineering performance of MSFRC is typically evaluated using flexural and residual strength parameters. Standards commonly rely on test methods such as ASTM C1609, EN 14651, or ASTM C1550 (Round Panel Test).

Flexural Strength (Residual Strength)

Flexural residual strength is the primary indicator of how MSFRC behaves after cracking.Key engineering metrics include:

• fR,1: Residual strength at Serviceability Limit State

• fR,3: Residual strength at Ultimate Limit State

• Load-CMOD curve performance

• Toughness indices

High-performance macro synthetic fibers—such as twisted, embossed, or fibrillated designs—provide stable post-crack load-carrying capacity comparable to steel fibers in many applications.

Energy Absorption (Toughness)

Energy absorption is critical for shotcrete, pavements, and impact-loaded structures.

Energy absorption capacity is influenced by:

• Fiber dosage (typically 3–8 kg/m³ for structural MSFRC)

• Fiber geometry (twisted, embossed, fibrillated)

• Bonding strength between fiber and cement matrix

MSFRC provides excellent ductility, allowing concrete to deform without sudden brittle failure, enhancing overall safety and durability.