Fiber Reinforced Polymer
(GFRP/CFRP Rebar — ASTM D7205)

Mechanical testing of glass and carbon fibre reinforced polymer (GFRP/CFRP) composite bars for concrete reinforcement — determining tensile strength, elastic modulus and rupture strain per ASTM D7205.

Overview

What is the Fiber Reinforced Polymer (FRP) Bar Testing?

Fiber Reinforced Polymer (FRP) Bars — particularly Glass FRP (GFRP) and Carbon FRP (CFRP) — are corrosion-resistant, non-magnetic, lightweight alternatives to conventional steel rebar for concrete reinforcement in aggressive environments. FRP bars have high tensile strength but lower elastic modulus than steel and fail in a linear-elastic brittle manner.

At Global Lab, FRP bar testing is conducted as per ASTM D7205 covering tensile strength, elongation at break and elastic modulus. These properties are the primary design inputs for FRP-reinforced concrete structures per ACI 440.1R. Our NABL-calibrated 1000kN UTM with extensometer provides accurate FRP tensile characterisation.

ASTM D7205 Compliant

Tensile strength, elastic modulus and rupture strain per ASTM D7205.

All FRP Types

GFRP, CFRP and AFRP (aramid) bars of all diameters tested.

Guaranteed Ultimate Tensile Strength

ffu* and design tensile strength (ffu) calculated per ACI 440.1R.

Linear-Elastic Behaviour Verified

Full stress-strain curve confirms linear-elastic brittle failure mode.

NABL Certified Reports

All results on NABL-accredited letterhead per ASTM D7205.

Batch Acceptance Testing

Minimum 5 specimens per ASTM D7205 for statistically valid batch acceptance.

Test in Action

Fiber Reinforced Polymer (FRP) Bar Testing — Site Images

FRP Machine

FRP

Brittle Rupture Failure at Ultimate Load

FRP TMT

Test Procedure

How the Fiber Reinforced Polymer (FRP) Bar Testing is Conducted

1

End Anchor Preparation

Steel pipe anchors filled with expanding cement grout applied to both ends of FRP bar to prevent gripping failure.
2

Gauge Length Marking

50× diameter gauge length marked on FRP bar per ASTM D7205.
3

Extensometer Attachment

Clip-on extensometer attached at gauge length for accurate strain measurement.
4

Tensile Test Execution

Load applied at 0.5–2% strain/min until bar rupture. Force and strain recorded continuously.
5

ACI 440 Design Properties

ffu* = average tensile strength − 3σ. Ef = elastic modulus. NABL report issued within 3 days.

Standards & Specifications

Applicable Test Standards

Standard	Title	Scope	Type
ASTM D7205	Standard Test Method for Tensile Properties of Fiber Reinforced Polymer Matrix Composite Bars	FRP Tensile Test	ASTM
ACI 440.1R	Guide for the Design and Construction of Structural Concrete Reinforced with FRP Bars	FRP Design	ACI
ISIS Canada	Reinforcing Concrete Structures with FRP — Design Manual No. 3	FRP Design	ISIS
ASTM D7337	Standard Test Method for Tensile Creep Rupture of FRP Composite Bars	Creep Rupture	ASTM

Applications

Where is the CAPO Test Used?

Marine and coastal concrete structures — bridge decks, piers and seawalls

MRI suite and sensitive electronics building concrete slabs (non-magnetic)

Chemical plant and industrial floor concrete in corrosive environments

Precast tunnel segments and underground structures exposed to chlorides

Bridge deck overlays and parking structure rehabilitation with GFRP

Research and structural acceptance testing for FRP reinforced structures

Why Choose Global Lab

Our Advantages

NABL Accredited ReportsLegally valid ASTM D7205 certificates for FRP material acceptance.

ACI 440 Design PropertiesGuaranteed UTS (ffu*) calculated per ACI 440.1R for structural design.

All Diameters & TypesGFRP, CFRP, AFRP from 6mm to 32mm diameter tested.

Fast 3-Day TurnaroundComplete FRP tensile test report within 3 working days.

Autovity Digital ReportsStress-strain curves and material certificates accessible digitally.

Pan-India CoverageFRP testing at all 7 NABL lab locations.

Fiber Reinforced Polymer(GFRP/CFRP Rebar — ASTM D7205)