ASTM D7957/D7957M-22

Standard Specification for Solid Round Glass Fiber Reinforced Polymer Bars for Concrete Reinforcement

ABSTRACT
This specification covers glass fiber reinforced polymer (GFRP) bars, provided in cut lengths and bent shapes and having an external surface enhancement for concrete reinforcement. It specifies the property limits and test methods for qualification, quality control and certification of GFRP bars, the geometric and mechanical property requirements, and minimum inside bend diameter of bent bars. Physical properties include fiber mass content, glass transition temperature, degree of cure, and bar sizes), whereas mechanical properties include ultimate tensile force, tensile modulus of elasticity, ultimate tensile strain, transverse shear strength, and bond strength.
This specification also covers the manufacturing process for constituent materials, namely, reinforcing fibers and matrix resins; durability properties (moisture absorption, resistance to alkaline environment); sampling (product qualification, quality control and certification); product certification; and markings and traceability.
SCOPE
1.1 This specification covers glass fiber reinforced polymer (GFRP) bars, provided in cut lengths and bent shapes and having an external surface enhancement for concrete reinforcement. Bars covered by this specification shall meet the requirements for geometric, material, mechanical, and physical properties described herein.  
1.2 Bars produced according to this standard are qualified using the test methods and must meet the requirements given by Table 1. Quality control and certification of production lots of bars are completed using the test methods and must meet the requirements given in Table 2.    
1.3 The text of this specification references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables) shall not be considered as requirements of the specification.  
1.4 The following FRP materials are not covered by this specification:  
1.4.1 Bars made of more than one load-bearing fiber type (that is, hybrid FRP).  
1.4.2 Bars having no external surface enhancement (that is, plain or smooth bars, or dowels).  
1.4.3 Bars with geometries other than solid, round cross sections.  
1.4.4 Pre-manufactured grids and gratings made with FRP materials.  
1.5 This specification is applicable for either SI (as Specification D7957M) or inch-pound units (as Specification D7957).  
1.6 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Jan-2022
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: D30 - Composite Materials
• Drafting Committee: D30.10 - Composites for Civil Structures

Relations

• Refers: ASTM D7913/D7913M-14(2020) - Standard Test Method for Bond Strength of Fiber-Reinforced Polymer Matrix Composite Bars to Concrete by Pullout Testing
• Effective Date: 01-Feb-2020

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D7957/D7957M −22
Standard Specification for
Solid Round Glass Fiber Reinforced Polymer Bars for
1
Concrete Reinforcement
This standard is issued under the fixed designation D7957/D7957M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope system shall be used independently of the other, and values
from the two systems shall not be combined.
1.1 This specification covers glass fiber reinforced polymer
1.7 This standard does not purport to address all of the
(GFRP) bars, provided in cut lengths and bent shapes and
safety concerns, if any, associated with its use. It is the
havinganexternalsurfaceenhancementforconcretereinforce-
responsibility of the user of this standard to establish appro-
ment. Bars covered by this specification shall meet the require-
priate safety, health, and environmental practices and deter-
ments for geometric, material, mechanical, and physical prop-
mine the applicability of regulatory limitations prior to use.
erties described herein.
1.8 This international standard was developed in accor-
1.2 Bars produced according to this standard are qualified
dance with internationally recognized principles on standard-
using the test methods and must meet the requirements given
ization established in the Decision on Principles for the
by Table 1. Quality control and certification of production lots
Development of International Standards, Guides and Recom-
ofbarsarecompletedusingthetestmethodsandmustmeetthe
mendations issued by the World Trade Organization Technical
requirements given in Table 2.
Barriers to Trade (TBT) Committee.
1.3 The text of this specification references notes and
2. Referenced Documents
footnotes which provide explanatory material. These notes and
2
footnotes (excluding those in tables) shall not be considered as
2.1 ASTM Standards:
requirements of the specification.
A615/A615M SpecificationforDeformedandPlainCarbon-
Steel Bars for Concrete Reinforcement
1.4 The following FRP materials are not covered by this
C904 Terminology Relating to Chemical-Resistant Nonme-
specification:
tallic Materials
1.4.1 Bars made of more than one load-bearing fiber type
D570 Test Method for Water Absorption of Plastics
(that is, hybrid FRP).
D792 Test Methods for Density and Specific Gravity (Rela-
1.4.2 Bars having no external surface enhancement (that is,
tive Density) of Plastics by Displacement
plain or smooth bars, or dowels).
D2584 Test Method for Ignition Loss of Cured Reinforced
1.4.3 Bars with geometries other than solid, round cross
Resins
sections.
D3171 Test Methods for Constituent Content of Composite
1.4.4 Pre-manufactured grids and gratings made with FRP
Materials
materials.
D3878 Terminology for Composite Materials
1.5 This specification is applicable for either SI (as Speci-
D7205/D7205M Test Method for Tensile Properties of Fiber
fication D7957M) or inch-pound units (as Specification
Reinforced Polymer Matrix Composite Bars
D7957).
D7617/D7617M Test Method for Transverse Shear Strength
of Fiber-reinforced Polymer Matrix Composite Bars
1.6 Units—The values stated in either SI units or inch-
D7705/D7705M Test Method for Alkali Resistance of Fiber
pound units are to be regarded separately as standard. The
Reinforced Polymer (FRP) Matrix Composite Bars used
values stated in each system are not necessarily exact equiva-
in Concrete Construction
lents; therefore, to ensure conformance with the standard, each
D7913/D7913M Test Method for Bond Strength of Fiber-
Reinforced Polymer Matrix Composite Bars to Concrete
by Pullout Testing
1
This specification is under the jurisdiction of ASTM Committee D30 on
Composite Materials and is the direct responsibility of Subcommittee D30.10 on
2
Composites for Civil Structures. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 1, 2022. Published March 2022. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2017. Last previous edition approved in 2017 as D7957/D7957M – 17. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D7957_D7957M-22. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D7957/D7957M−22
A
TABLE 1 Property Limits and Test Methods for Qualification
Property Limit Test Method
Mean Glass
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7957/D7957M − 17 D7957/D7957M − 22
Standard Specification for
Solid Round Glass Fiber Reinforced Polymer Bars for
1
Concrete Reinforcement
This standard is issued under the fixed designation D7957/D7957M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This specification covers glass fiber reinforced polymer (GFRP) bars, provided in cut lengths and bent shapes and having an
external surface enhancement for concrete reinforcement. Bars covered by this specification shall meet the requirements for
geometric, material, mechanical, and physical properties described herein.
1.2 Bars produced according to this standard are qualified using the test methods and must meet the requirements given by Table
1. Quality control and certification of production lots of bars are completed using the test methods and must meet the requirements
given in Table 2.
1.3 The text of this specification references notes and footnotes which provide explanatory material. These notes and footnotes
(excluding those in tables) shall not be considered as requirements of the specification.
1.4 The following FRP materials are not covered by this specification:
1.4.1 Bars made of more than one load-bearing fiber type (that is, hybrid FRP).
1.4.2 Bars having no external surface enhancement (that is, plain or smooth bars, or dowels).
1.4.3 Bars with geometries other than solid, round cross sections.
1.4.4 Pre-manufactured grids and gratings made with FRP materials.
1.5 This specification is applicable for either SI (as Specification D7957M) or inch-pound units (as Specification D7957).
1.6 Units—The values stated in either inch-poundSI units or SIinch-pound units are to be regarded as standard. Within the text,
the inch-pound units are shown in brackets. separately as standard. The values stated in each system are not necessarily exact
equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other.
Combiningother, and values from the two systems may result in nonconformance with the specification.shall not be combined.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1
This specification is under the jurisdiction of ASTM Committee D30 on Composite Materials and is the direct responsibility of Subcommittee D30.10 on Composites
for Civil Structures.
Current edition approved Aug. 1, 2017Feb. 1, 2022. Published August 2017March 2022. Originally approved in 2017. Last previous edition approved in 2017 as
D7957/D7957M – 17. DOI: 10.1520/D7957_D7957M-17.10.1520/D7957_D7957M-22.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D7957/D7957M − 22
A
TABLE 1 Property Limits and Test Methods for Qualification
Property Limit Test Method
Mean Glass Transition Temperature Midpoint temperature $100 °C [212 °F] ASTM E1356
Mean Degree of Cure $95 % ASTM E2160
Mean Measured Cross-Sectional Area Table 3 ASTM D7205/D7205M, subsection 11.2.5.1
B
Guaranteed Ultimate Tensile Force Table 3 ASTM D7205/D7205M
Mean Tensile Modulus of Elasticity $44,800 MPa [6 500 000 psi] ASTM D7205/D7205M
Mean Ultimate Tensile Strain $1.1 % ASTM D7205/D7205M
B
Guaranteed Transverse Shear Strength $131 MPa [19 000 psi] ASTM D7617/D7617M
B
Guaranteed Bond Strength $7.6 MPa [1100 psi] ASTM D7913/D7913M
Mean Moisture Absorption to Saturation #1.0 % to saturation at 50 °C [122 °F] ASTM D570, subsection 7.4
$80 % of initial mean ultimate tensile force following
Mean Alkaline Resistance ASTM D7705/D7705M, Procedure A
90 days at 60 °C [140 °F]
B
Guaranteed Ultimate Tensile Force of Bent Portion
$60 % of the values in Table 3 ASTM D7914/D7914M
of Bar
A
For the determination of the mean and guaranteed properties, at least 24 samples shall be obtained in groups of eight or more from three or more different production
lots. The mean and guaranteed properties shall satisfy the limits.
B
Guaranteed property is defined in 3.2.53.2.4.
A,B
TABLE 2 Property Limits and Test Methods for Qua
...