Carbon Fiber Structural Reinforcement Fabric vs. Ordinary Carbon Fiber Fabric

Carbon fiber fabric has been used in building structure reinforcement for over thirty years, forming a specialized product category—carbon fiber building reinforcement fabric (also known as carbon fiber strengthening fabric or carbon fiber sheet). Although its raw material is also carbon fiber, it differs significantly from ordinary industrial or sports equipment carbon fiber fabric in product standards, performance requirements, and application positioning.

Basic Definition and Application Differences

Carbon Fiber Building Reinforcement Fabric

Specifically designed for reinforcing and strengthening building structures, this carbon fiber fabric is combined with matching resin to form a carbon fiber reinforced polymer (CFRP) system. It is bonded to the surface of concrete, masonry, wood, and other structures to bear additional loads.

Main Applications:

Bend reinforcement of beams and slabs; shear reinforcement of columns and shear walls; seismic reinforcement of columns (confined concrete); crack repair and load-bearing capacity enhancement; reinforcement when the structural function changes.

Ordinary Carbon Fiber Fabric

Refers to carbon fiber fabric used in general composite material products, such as sports equipment, automotive parts, industrial components, and decorative parts.

Main Applications:

Bicycle frames, rackets, fishing rods; automotive modification parts; wind turbine blades; industrial pipes, storage tanks; exterior decorative parts

Specific Differences in Mechanical Properties

1. Tensile Strength

Building reinforcing fabric: Grade I ≥ 3400 MPa, Grade II ≥ 3000 MPa (per GB 50728). High strength assurance, strict factory testing. Strength tested with resin (composite performance).

General-purpose fabric: T300: 3500–4000 MPa; T700: 4500–5000 MPa. Batch variability. Usually tested dry, without resin.

2. Tensile Modulus

Building reinforcing fabric: Standard modulus ≥ 240 GPa, high modulus ≥ 300 GPa. Modulus is key for design.

General-purpose fabric: T300: 230 GPa; T700: 240 GPa; M40: 377 GPa. No mandatory grades; selected by stiffness needs.

3. Elongation

Building reinforcing fabric: ≥ 1.6% (Grade I) or ≥ 1.5% (Grade II). Ensures ductility, prevents brittle failure.

General-purpose fabric: T700: 1.8%–2.1%; M40: 0.6%–0.8%. No minimum requirement; varies by type.

Selection Principles

For structural strengthening projects, specialized structural reinforcement fabrics must be used.

When structural safety is involved, it is mandatory to use construction-specific fabrics that are accompanied by test reports and comply with national standards.

Standard carbon fiber fabrics cannot provide the guaranteed strength and long-term performance required by structural designs.

Select Grade Based on Strength Requirements

General Strengthening: Primarily Grade I fabric (3400 MPa).

Secondary Components or Temporary Strengthening: Grade II fabric (3000 MPa).

Select Modulus Based on Stiffness Requirements

Strengthening of Standard Beams and Slabs: Standard Modulus (240 GPa).

Strict Deflection Control: High Modulus (300 GPa or higher).

Select Areal Weight Based on Number of Layers

The thickness of a single layer is determined by its areal weight; 200g, 300g, and 600g weights correspond to different design thicknesses.

When applying multiple layers, the required overlap length must be taken into account.

Mandatory System Compatibility

The carbon fabric, primer, impregnating resin, and leveling putty must all belong to the same product system to ensure full compatibility.

Summary

While both use the same raw material, structural reinforcement fabrics and standard carbon fiber fabrics serve different purposes. Reinforcement fabrics prioritize structural safety—requiring guaranteed strength, modulus grades, long-term durability, and resin compatibility. Standard fabrics focus on processability, appearance, and cost. For building strengthening, always use certified reinforcement fabrics and follow construction codes to ensure safety and effectiveness.