6-Inch 450GSM Carbon Fiber — ASTM-Tested Laminated Properties for Engineered Structural Repair
The Specification-Grade Choice. Full ASTM Laminated Test Data for Flexural Strength, Shear Strength, and Tensile Modulus.
Full ASTM laminated composite data — D3039, D7264 (flexural), D2344 (shear)
5,800 MPa dry tensile strength — highest in the lineup
255 GPa tensile elastic modulus — stiffest fiber in the range
4,840 MPa laminated tensile strength (ASTM D3039) — documented composite performance
921 MPa flexural strength (ASTM D7264) for bending load resistance
96 MPa interlaminar shear strength (ASTM D2344)
For poured concrete walls with a sound substrate requiring documented test data
900ml of Startech structural epoxy included per 10 ft ordered
Unidirectional Grade 1 — 164 ft (50 m) maximum roll length
10 ft minimum order — 150 ft for volume discount
Grinding equipment required to prepare surface before application
Free Technical Support — 1-866-445-3984
Ships USA & Canada
Why the 450GSM Exists — The Role of Laminated Test Data
All carbon fiber reinforcement products are tested in two states: as dry fiber, and as a cured composite laminate (fiber plus cured epoxy matrix). Dry fiber tensile data tells you how strong the fiber is before installation. Laminated composite data tells you how the finished, installed repair actually performs — it accounts for the epoxy contribution, fiber-matrix interaction, void content, and the failure modes specific to the bonded composite system.
For most residential and light commercial repairs, dry fiber data is sufficient to select the right product. For structural engineering assessments — cases where a structural engineer must sign off on a repair specification, where building permit documentation is required, or where the repaired element is load-bearing in a way that affects life safety — the engineer needs laminated composite test data. Specifically, they need the values that appear in ASTM D3039 (tensile), ASTM D7264 (flexural), and ASTM D2344 (interlaminar shear). These are the properties that appear in structural calculation sheets and repair specifications.
The 450GSM product is the fiber in the NextStar lineup carries a complete set of these laminated composite test results. It is supplied to contractors and specifying engineers who need to reference a product with documented composite performance — not just raw fiber tensile numbers.
Performance in Context — How 450GSM Compares to 300GSM and 600GSM
The 450GSM sits between 300GSM and 600GSM in fiber density, but it is not simply a midpoint in performance. Its elastic modulus of 255 GPa is the highest in the NextStar carbon fiber range — stiffer than the 600GSM at 240 GPa and stiffer than the 300GSM products. Higher modulus means less elastic deflection under the same applied load. For a wall that is being held against active soil pressure, a higher modulus strap deflects less before equilibrium — which means less wall movement occurs before the strap is fully engaged.
Its 1.95% elongation at break under laminated test conditions (ASTM D3039) is also the highest in the lineup — giving it more ductility before failure than the 300GSM (1.6%) or 600GSM (1.5%). This is not a weakness; in structural engineering, controlled ductility before failure is a desirable property that prevents sudden catastrophic rupture and gives warning before the repair is overloaded.
What Is Included Per Order
6-Inch 450GSM Unidirectional Carbon Fiber (by the foot, minimum 10 ft):
Supplied uncut. Grade 1 unidirectional. Maximum roll 164 ft (50 m).
Startech Hi-Modulus Fiber Matrix Structural Epoxy — 900ml per 10 ft ordered:
100% solids, solvent-free, moisture-insensitive. 2:1 mix ratio. Cures as low as 40°F (4°C).
Consumables (scaled to order volume):
Roller tray, roller head, square trowel, mixing bucket, nitrile gloves and instructions.
450GSM Carbon Fiber Technical Specifications
| Property |
Dry Value |
Laminated Value |
Standard |
| Weave |
Unidirectional |
— |
— |
| Width |
6 in (15.24 cm) |
— |
— |
| Basis Weight |
450 GSM |
— |
— |
| Max Roll Length |
164 ft (50 m) |
— |
— |
| Tensile Strength |
5,800 MPa |
4,840 MPa |
ASTM D3039 |
| Tensile Elastic Modulus |
255.53 GPa |
255.53 GPa |
ASTM D3039 |
| Elongation at Break |
1.6% |
1.95% |
ASTM D3039 |
| Flexural Strength |
— |
921 MPa |
ASTM D7264 |
| Interlaminar Shear Strength |
— |
96 MPa |
ASTM D2344 |
| Density |
1.8 g/cm³ |
— |
— |
Installation — 6-Inch 450GSM on Poured Concrete
Watch the installation video →
Before starting: repair any active cracks with epoxy injection and allow full cure.
- Plan strap locations. Vertical straps at maximum 4 ft on center. For documented engineering repairs, follow the spacing specified in your structural report — the ASTM data for this product is provided to support structural calculations.
- Prepare the wall surface. Grind the full strap contact area to bare concrete with a diamond cup wheel. Remove all paint, contamination, loose aggregate, and surface laitance. Vacuum thoroughly. Surface quality directly affects the composite bond strength — a poorly prepared surface defeats the purpose of using a specification-grade fiber.
- Cut straps to length. Cut on a clean, flat surface. The 450GSM is a denser fabric than 300GSM — use a sharp blade and cut cleanly to avoid fraying the fiber ends, which can affect appearance on a finished structural repair.
- Mix the epoxy. Mix Startech Fiber Matrix Epoxy 2:1 by volume until fully uniform. The 450GSM fiber density requires complete wet-out for the laminated properties to be achieved — mix only as much as you can apply within the pot life.
- Apply epoxy bed to wall. Apply a consistent epoxy bed to the prepared wall surface using trowel and roller. For a specification repair, apply to the full strap width uniformly — inconsistent bed thickness affects composite property consistency.
- Saturate the strap. Coat the strap bonding face with epoxy. Ensure the epoxy is worked into the fiber, not just surface-applied.
- Place and consolidate. Position strap against wall, roll firmly from center outward. Apply firm, even pressure across the full 6-inch width.
- Trowel to full saturation. Work epoxy through the fabric depth with the flat trowel. The 450GSM density requires thorough troweling to drive epoxy through the full fiber cross-section. Full saturation is required for the laminated test values to be achievable in the installed repair.
- Final roll and cure. Re-roll the surface smooth. Allow full 24-hour cure at 40°F or above before any coating, loading, or assessment.
Tips & Notes
1. Sound poured concrete substrate required. Like the 600GSM, the 450GSM requires a substrate strong enough to transfer high interface loads. It is not suitable for block walls or deteriorated concrete. Use the 12-inch 300GSM for those applications.
2. Full epoxy saturation is the quality gate. The ASTM laminated properties this product is specified for are achieved only when the installed composite is fully saturated with no dry fiber zones. Partial saturation produces a composite with unpredictable and lower properties.
3. Specifying engineers. If you are preparing a structural specification and need the full ASTM test data sheet for this product, call 1-866-445-3984 — we can provide the laboratory test reports directly.
4. Comparing 450GSM vs 600GSM. The 600GSM has higher raw tensile strength (4,500 MPa) and the 450GSM has the highest elastic modulus (255 GPa) and the only complete ASTM laminated data set. For projects where a structural engineer needs documented test values, 450GSM is the specification product.
5. Volume orders. See the bulk carbon fiber page for contractor pricing across all widths and GSM options.
Common Questions — 6-Inch 450GSM Carbon Fiber
What makes the 450GSM a specification-grade product?
The 450GSM has a documented set of ASTM laminated composite test results — tensile (D3039), flexural (D7264), and interlaminar shear (D2344) — tested on the actual cured fiber-epoxy composite, not just the dry fiber. These are the values that structural engineers reference when writing repair specifications and submitting permit documentation. The other products in the lineup provide dry fiber tensile data, which is sufficient for most residential repairs but may not meet the documentation requirements of an engineered structural report.
Why does the 450GSM have the highest elastic modulus in the lineup?
At 255.53 GPa, the 450GSM has a higher elastic modulus than the 600GSM (240 GPa) or any of the 300GSM products. Elastic modulus determines how much a material deflects under load — higher modulus means less deflection before equilibrium. For a wall being held against active soil pressure, a higher modulus strap reaches its design load at a smaller amount of wall movement. This is the stiffest strap in the NextStar range for a given strap width.
What does ASTM D7264 flexural strength measure and why does it matter?
ASTM D7264 tests the resistance of the cured composite to bending loads — the point at which the laminate fails when loaded transversely across its surface. This is relevant for carbon fiber straps on walls because the strap is not loaded purely in tension along its length — there is also a peeling or bending component at the bonded ends where the strap terminates. At 921 MPa, the 450GSM has substantially greater resistance to this type of loading than a product with no laminated flexural data.
What is interlaminar shear strength and when does it matter?
Interlaminar shear strength (ASTM D2344) measures resistance to sliding failure between fiber layers within the composite — the force required to cause the laminate to delaminate internally rather than fail at the fiber-concrete bond. At 96 MPa, the 450GSM has high resistance to this failure mode. It is particularly relevant in applications where the strap is under combined tensile and shear loading — such as diagonal straps on a wall experiencing both lateral and settlement movement.
Is the 450GSM suitable for residential DIY repairs or is it primarily a contractor product?
The installation process is identical to the other carbon fiber products — no additional skills or tools are required. The difference is documentation, not difficulty. A homeowner who needs to provide a structural engineer's sign-off for a sale, a permit, or insurance purposes may specifically require a product with ASTM laminated test data. In those cases, the 450GSM provides the data the engineer needs. For straightforward residential repairs without documentation requirements, the 8-inch 300GSM is the standard choice.
Can I get the full ASTM lab test reports for this product?
Yes. Call 1-866-445-3984 or contact us by email. We provide the laboratory test reports to specifying engineers, contractors, and permit applicants who need the full ASTM test documentation for the 450GSM laminated composite.
Need the ASTM test data for a structural specification? Call 1-866-445-3984.
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