Published by pultrx, the export trading company of Henan Zhongsheng. This is a buyer planning guide; the manufacturer confirms project specifications in writing.
The short answer
Use GFRP rebar where corrosion of steel reinforcement would control the service life of the structure, or where the concrete must be free of metal. Keep steel rebar where the member must yield and absorb energy, where a fire resistance rating is required, where the structure resists seismic forces, or where bars have to be bent and adjusted on site. Many projects use both, with GFRP in the exposed deck, wall face or splash zone and steel in the protected core, as long as the governing code allows the arrangement.
GFRP rebar is a strong candidate
- Bridge decks, barriers and approach slabs exposed to deicing salts
- Seawalls, piers, docks and other concrete in seawater or splash zones
- Parking structures, wastewater tanks and chemical containment
- MRI rooms, substations, transformer bases and other members that must be nonmagnetic
- Tunnel soft eyes and temporary walls that a boring machine must cut through
Steel rebar usually stays
- Members of a seismic-force-resisting system
- Elements that need a fire resistance rating
- Prestressed concrete, lightweight concrete and deep beams under ACI 440.11-22
- Details that rely on field bending or on-site adjustment of bent bars
- Anchoring to concrete and diaphragms, which the 2022 code does not address
GFRP rebar vs steel rebar: key differences
| Property | GFRP rebar | Steel rebar |
|---|---|---|
| Corrosion in chlorides | Does not corrode | Corrodes unless coated, galvanized or stainless |
| Modulus of elasticity | 44.8 GPa minimum (ASTM D7957, 2017) | 200 GPa |
| Behavior at failure | Linear elastic to rupture, no yield point | Yields, then strain hardens |
| Tensile strength | Higher than the yield strength of common steel grades | Set by the bar grade |
| Strength at a bend | Lower than in the straight bar | Bent to standard bend diameters |
| Bending | Bends made in the factory only | Bent in the shop or on site |
| Weight | About one quarter of steel | Reference |
| Magnetic and electrical | Nonmagnetic, nonconductive | Magnetic, conductive |
| Fire | Resin softens; susceptible to fire and smoke production | Retains strength to higher temperatures |
| Thermal expansion across the bar | High | Similar to concrete |
Design: why the bar schedule changes
ACI CODE-440.11-22 follows the chapter numbering of ACI 318-19, so engineers find the same topics in the same places. The design rules differ. Because GFRP has a lower modulus, the neutral axis depth and the concrete compression zone are smaller, cracks are wider and deflections larger. Shear design changes too: GFRP gives less dowel action and the concrete contribution is calculated differently. The code ignores GFRP bars in compression, and for columns it sets a tensile strain limit of 1 % in the bars.
Because the bar does not yield, a GFRP-reinforced member gives less warning before failure than a ductile steel-reinforced one. The code compensates with its own strength reduction factors and failure-mode checks. The practical consequence for a buyer is simple: a GFRP bar schedule is not the steel schedule with the material name changed. Expect different bar sizes, spacings and covers, and expect the engineer to ask for the guaranteed properties of the bar you intend to buy.
Code limits: ACI 440.11 and the 2024 IBC
- Scope: nonprestressed concrete reinforced with solid round GFRP bars conforming to ASTM D7957. Hybrid members with mixed reinforcement types are outside the scope.
- Not covered in the 2022 edition: diaphragms, plain concrete, anchoring to concrete, earthquake-resistant structures, strut-and-tie models, lightweight concrete, prestressed concrete, deep beams and shotcrete.
- Seismic: GFRP-reinforced members may not form part of the seismic-force-resisting system in seismic design categories B and C, and no GFRP-reinforced member is permitted in structures assigned to categories D, E and F.
- 2024 IBC section 1901.2.1 permits cast-in-place structural concrete reinforced with ASTM D7957 GFRP bars and designed to ACI 440.11 where fire resistance ratings are not required, and only for seismic design category A.
- Outside the US, bridge owners and national agencies publish their own GFRP bar specifications and approval routes. Name the one that governs your project in the RFQ.
Corrosion, service life and where cost is compared
Chloride-induced corrosion of steel reinforcement is a main reason concrete bridge decks, marine structures and parking decks need repair. GFRP removes that mechanism, which is why the PCI review lists it as an alternative to epoxy-coated, galvanized and stainless steel bars rather than to plain black bar. Compare GFRP against the protected steel system the project would otherwise use, and include cover, sealers, cathodic protection, inspection and repair cycles where they apply. pultrx does not publish a rebar price per meter; the quotation for your bar schedule, qualification tests and delivery terms is the price that applies.
Bends, cutting and site handling
GFRP bars are made with a thermoset resin that is cured in the factory, so they cannot be bent in the field. Stirrups, hooks, L bars and other shapes are produced bent and are listed separately on the schedule, with bend radius and leg lengths. A bent bar has lower tensile strength around the bend than in its straight length, and many owner specifications do not allow bent bars to be cut on site. Where a detail cannot be formed, the usual alternative is a lap splice with straight bars, sized by the engineer.
- Cut straight bars with a diamond or abrasive blade; do not shear them. Plan dust control.
- Tie with coated wire or nonmetallic ties as the specification requires.
- Bars are light and float in wet concrete more easily than steel: tie them down to chairs and secure the cage before the pour.
- Store bars off the ground, supported along their length, and covered from sunlight for long storage.
- Do not walk or drive equipment over bars in a way that crushes the surface deformations or sand coating.
How to order GFRP rebar and mesh
Henan Zhongsheng, our factory in Xinxiang, makes GFRP reinforcing bars and GFRP mesh. pultrx, the factory's directly affiliated export trading company in Shanghai, quotes and exports the bars. The factory's catalogue lists bar styles and customizable diameter, length, color, winding method and surface treatment. A catalogue listing does not establish conformity with ASTM D7957 or any other specification; qualification is agreed per order and backed by test reports traceable to the production lot.
| Send | Why it matters |
|---|---|
| Engineer-approved bar schedule: sizes, lengths, quantities, bar marks | GFRP bars are produced to length; there is no cutting from stock on site |
| Bent shapes with bend radius, leg lengths and bending schedule | Bends are factory-made and cannot be corrected on site |
| Governing specification and edition (for example ASTM D7957, an owner specification) | Defines property limits, test methods and lot certification |
| Required guaranteed tensile strength and modulus by bar size | Engineers design with guaranteed values, not catalogue averages |
| Surface form: sand coating, helical wrap, ribs | Bond to concrete depends on the surface the design assumed |
| Qualification and lot tests, witness and third-party requirements | Tests and sampling are quoted and scheduled before production |
| Mesh: bar size, spacing, panel size, joint type | Mesh is produced on a separate line and quoted as its own item |
| Delivery sequence, bundle size, labeling and destination | Lets bundles match the pour sequence and site storage |
- 01
Schedule and specification
Buyer or project engineer
Send the bar schedule, bent shapes, governing specification and test requirements.
- 02
Technical review
Factory engineering
The factory confirms bar sizes, surface form, bend shapes and the tests it can report for the ordered bar.
- 03
Quotation
pultrx Shanghai export office
Price, qualification tests, lot certification, packing, Incoterm and lead time are stated in writing.
- 04
Production and lot records
Factory + pultrx
Bars are produced, tested and labeled by lot; records are released with the shipment as agreed.
See the bar and mesh forms, what the quotation includes and the acceptance checks for a GFRP rebar order. GFRP rebar: bar schedules and qualification
Planning your own production? Submit the bar requirements for feasibility review. The current Haoli listings do not establish rebar or mesh production capability. Equipment selection and feasibility review
Sources and further reading
- PCI Journal: New ACI 440.11 code adopted for design of concrete reinforced with GFRP bars (Myers, Gremel, Ericson, Van Kampen, March-April 2023)
Scope and exclusions of ACI CODE-440.11-22, key differences from steel reinforcement, the role of ASTM D7957 and the text of 2024 IBC section 1901.2.1.
- ASTM D7957/D7957M-22 (store page): Standard specification for solid round glass fiber reinforced polymer bars for concrete reinforcement
Material specification referenced by ACI 440.11. The 2017 edition sets a minimum tensile modulus of 44.8 GPa (6,500 ksi); check the edition named in your project specification.
- ACI CODE-440.11-22: Building code requirements for structural concrete reinforced with GFRP bars
Preview of the code. Design questions belong to the project engineer working from the full code text.
Questions buyers ask
- Is GFRP rebar stronger than steel rebar?
- GFRP bars have higher tensile strength than the yield strength of common steel grades, but about a quarter of the stiffness and no yield point. Members reinforced with GFRP crack wider and deflect more, so the design usually needs different bar sizes or spacing.
- Can GFRP rebar be bent on site?
- No. The resin is cured in the factory, so hooks, stirrups and other bent shapes must be ordered bent. Bent bars have lower strength at the bend than in the straight length.
- Is GFRP rebar allowed by the building code?
- In the US, ACI CODE-440.11-22 covers design with solid round GFRP bars conforming to ASTM D7957, and the 2024 IBC permits it for cast-in-place structural concrete where no fire resistance rating is required and only in seismic design category A. Other jurisdictions and bridge owners have their own rules.
- Can GFRP and steel rebar be used in the same structure?
- Projects often use GFRP in the corrosion-exposed elements and steel elsewhere. ACI 440.11-22 does not cover hybrid members that mix reinforcement types, so the engineer decides where each bar type is used and how the interfaces are designed.
- Does your GFRP rebar conform to ASTM D7957?
- Conformity is confirmed per order, not by the catalogue. Name the specification and edition in the RFQ; the quotation states the tests and lot certification supplied with the bars.
Ready to move from reading to a scoped quotation?
Send a GFRP rebar schedule