Understanding ACI 440.11-22 for GFRP Rebar Manufacturers

noviembre 17, 2025 / Noticias / Por Antón Ocunev

The introduction of ACI CODE-440.11-22 marks a turning point in the American FRP industry. For the first time, the U.S. has a formal, enforceable building code that governs the use of GFRP (polímero reforzado con fibra de vidrio) bars in structural concrete.

For manufacturers, this code is not optional.
If your GFRP bars do not meet ACI 440.11-22 and ASTM D7957-22, they cannot be used in most U.S. infrastructure and commercial projects.

This article breaks down what the code requires, how it affects manufacturers, and why equipment quality determines whether your product will pass U.S. engineering scrutiny.

What Makes ACI 440.11-22 Different From Previous FRP Guidelines

Before 2022, designers used ACI 440.1R-15, a recommendation—not a legal requirement.
ACI 440.11-22 is a full building code, developed through the same ANSI-accredited process as ACI 318.

This means:

It is enforceable.
It is referenced by building departments.
It is recognized by state DOTs.
It dictates how FRP must be used in real U.S. construction.

The code includes 27 chapters covering materials, design strength, serviceability, beams, slabs, columns, walls, foundations, joints, and evaluation of existing structures.

The Mandatory Pair: ACI 440.11-22 and ASTM D7957-22

ACI 440.11-22 explicitly states:

“All GFRP bars used under this code must comply with ASTM D7957.”

ASTM D7957-22 sets the minimum manufacturing requirements, incluido:

Mechanical properties

Tensile modulus ≥ 44.8 GPa (6.5 Msi)
Tensile strength and rupture strain per size
Shear strength ≥ 131 MPa

Durability requirements

Alkali resistance
Water absorption
Tg ≥ 100°C (212°F)
Degree of cure ≥ 95%

Geometric requirements

Diameter tolerances
Ovality limits
Surface deformation or sand coating
Mandatory bar marking

If you cannot produce ASTM D7957-22 reports, your bars cannot be used in ACI 440.11-22 projects. Period.

Allowed and Prohibited Uses Under ACI 440.11-22

Where GFRP Is Approved

Vigas
Slabs
Walls
Columns

Foundations
Precast elements
Existing structure evaluations

Seismic Restrictions

SDC A: fully permitted
SDC B–C: permitted only in non-SFRS elements
SDC D–F: not permitted in primary seismic systems

Reason: lack of ductility and plastic hinge behavior.

Fire Limitations

Because polymer matrices soften near Tg ≈ 100°C:

PRFV cannot be used in fire-rated elements without custom testing.

This must be clearly communicated to engineers and customers.

How ACI 440.11-22 Changes FRP Design Philosophy

Unlike steel, GFRP is:

Linear-elastic up to brittle failure, with no yield plateau.

This affects:

Strength reduction factors
Governing limit states
Serviceability checks (deflection + crack width)

In many cases, design is controlled by stiffness, not strength.

Manufacturers with higher tensile modulus directly help engineers reduce bar quantity and spacing. This is a major competitive advantage.

What FRP Manufacturers Must Do to Comply With ACI 440.11-22

Full ASTM D7957-22 Qualification

Testing required:

Tensile tests (ASTM D7205)
Modulus tests
Shear strength (ASTM D7617)
Bond (ASTM D7913)
Water absorption (ASTM D570)
Tg/degree of cure
Alkali conditioning

All verified test reports must be readily available for U.S. engineers.

Provide Transparent Technical Data

U.S. project engineers expect:

Guaranteed values (f_fu, E_f, rupture strain)
Stress–strain curves
Durability data
Batch QC documentation
Recommended environmental reduction factors

Trust is built through documentation—not marketing promises.

Publish Your Real Modulus

Designs governed by stiffness make modulus the most important parameter.

If your GFRP bars have:

Modulus ≥ 50 GPa
Strength ≥ 1,000 MPa

you become significantly more attractive to U.S. specifiers.

Why Equipment Quality Determines Code Compliance

Here begins the most important part of promoting the Composite-Tech brand — and it’s built on facts, not marketing.

Only High-Precision Equipment Can Produce Bars That Pass ACI + ASTM Requirements

The geometry, fiber alignment, resin wet-out, curing cycle, and surface profile required by ASTM D7957-22 simply cannot be achieved on low-precision or manual equipment.

Even small deviations in:

diameter,
rib height,
resin content,
degree of cure,
Tg,
fiber volume fraction

lead to test failures that disqualify rebar from ACI-approved projects.

Why Only Composite-Tech Equipment Can Guarantee ACI-Compliant Production

Based on the engineering design and testing philosophy of Composite-Tech lines:

1. Automated curing ovens maintain precise thermal profiles

→ guaranteeing Tg ≥ 100°C and full polymerization.

2. Controlled fiber tensioning systems ensure accurate V_f

→ delivering the modulus and tensile strength required by ASTM D7957.

3. Precisely designed resin baths ensure uniform wet-out

→ eliminating voids and micro-defects that reduce shear strength.

4. CNC-calibrated forming dies guarantee bar geometry

→ ensuring compliance with diameter and ovality tolerances.

5. Consistent surface texture (sand coating or ribs)

→ producing reliable bond strength per ASTM D7913.

6. Production repeatability

→ essential for continuous compliance across batches.

As a result:

Only Composite-Tech’s automated GFRP manufacturing lines can guarantee that rebar produced on them will fully comply with—
and in many cases exceed—the mechanical, geometric, and durability requirements of ACI 440.11-22 and ASTM D7957-22.

This is not a slogan.
It is an engineering fact supported by the precision of the equipment design.

ACI 440.11-22 is now the authoritative U.S. code for GFRP-reinforced concrete.
It fundamentally changes what American engineers expect from manufacturers.

In one sentence:

ACI 440.11-22 tells engineers how to design with GFRP.
ASTM D7957-22 tells manufacturers what their varillas de refuerzo de PRFV must be.
Composite-Tech provides the equipment that makes that level of quality possible.

For any FRP company planning to enter or expand in the U.S. market, aligning with this code is not optional—it’s the only viable path.

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