ASTM A944-22

Standard Test Method for Comparing Bond Strength of Steel Reinforcing Bars to Concrete Using Beam-End Specimens

ABSTRACT
This test method deals with the standard procedures for establishing the relative bond strength of steel reinforcing bars in concrete using beam-end specimens. This test method shall determine the effects of surface preparation or condition (such as bar coatings) on the bond strength of deformed steel reinforcing bars to concrete. The bond strengths obtained using this test method shall not be directly applicable to the design of reinforced concrete members. The beam-end test specimen shall be fabricated by casting, and conditioned by curing prior to tensile load test. The test system shall consist of the loading system, compression reaction plate, and bar displacement measurement device.
SCOPE
1.1 This test method describes procedures to establish the relative bond strength of steel reinforcing bars in concrete.  
1.2 This test method is intended to determine the effects of surface preparation or condition (such as bar coatings) on the bond strength of deformed steel reinforcing bars (of sizes ranging from No. 3 to No. 11 [No. 10 to No. 36]) to concrete.  
1.3 The bond strengths obtained using this test method are not directly applicable to the design of reinforced concrete members.
Note 1: The bond strengths obtained using this test method are generally higher than obtained in development or splice tests using beams with the same embedment lengths. The results obtained using this test method should only be used for comparisons with results for other reinforcing bars tested using this method.  
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in brackets are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.5 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.  
1.6 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-Aug-2022
• ICS: 91.080.13 - Steel structures
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.05 - Steel Reinforcement

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: A944 − 22
Standard Test Method for
Comparing Bond Strength of Steel Reinforcing Bars to
1
Concrete Using Beam-End Specimens
This standard is issued under the fixed designation A944; 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* 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 This test method describes procedures to establish the
C192/C192M Practice for Making and Curing Concrete Test
relative bond strength of steel reinforcing bars in concrete.
Specimens in the Laboratory
1.2 This test method is intended to determine the effects of
E4 Practices for Force Calibration and Verification of Test-
surface preparation or condition (such as bar coatings) on the
ing Machines
bond strength of deformed steel reinforcing bars (of sizes
E575 Practice for Reporting Data from Structural Tests of
ranging from No. 3 to No. 11 [No. 10 to No. 36]) to concrete. Building Constructions, Elements, Connections, and As-
semblies
1.3 The bond strengths obtained using this test method are
not directly applicable to the design of reinforced concrete
3. Terminology
members.
3.1 Definitions of Terms Specific to This Standard:
3.1.1 bond strength, n—maximum measured load in a ten-
NOTE 1—The bond strengths obtained using this test method are
sile bond test of a steel reinforcing bar.
generally higher than obtained in development or splice tests using beams
with the same embedment lengths. The results obtained using this test
3.1.2 bonded length, n—the length of the test bar that is in
method should only be used for comparisons with results for other
contact with concrete.
reinforcing bars tested using this method.
3.1.3 concrete cover, n—minimum distance between the
1.4 The values stated in inch-pound units are to be regarded
surface of the test bar and the top or bottom of the test
as standard. The values given in brackets are mathematical
specimen.
conversions to SI units that are provided for information only
3.1.4 embedment length, n—the distance from the surface of
and are not considered standard.
the concrete test specimen to the installed end of the steel
1.5 This standard does not purport to address all of the reinforcing bar. This equals the sum of the lead length and the
safety concerns, if any, associated with its use. It is the bonded length.
responsibility of the user of this standard to establish appro-
3.1.5 lead length, n—the length of the test bar that is not in
priate safety, health, and environmental practices and deter-
contact with concrete but is between the surface of the concrete
mine the applicability of regulatory limitations prior to use.
test specimen and the bonded length.
1.6 This international standard was developed in accor-
3.1.6 relative rib area, n—ratio of the projected rib area
dance with internationally recognized principles on standard-
normal to bar axis to the product of the nominal bar perimeter
ization established in the Decision on Principles for the
and the center-to-center rib spacing.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1
This test method is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
2
A01.05 on Steel Reinforcement. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Sept. 1, 2022. Published November 2022. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1995. Last previous edition approved in 2015 as A944 – 10 (2015). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/A0944-22. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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A944 − 22
3.2 Symbols: 4.3 BarDisplacementMeasurements—Displacementsofthe
C = Concrete cover, in. [mm]. loaded and free ends of the steel reinforcing bar shall be
c
d = Nominal diameter of reinforcing bar, in. [mm]. measured with respect to the loaded and free surfaces,
b
ℓ = Embedment length, in. [mm]. respectively, of the concrete using suitable measurement de-
e
vices. Dial gages having the smallest division of not more than
4. App
...

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: A944 − 10 (Reapproved 2015) A944 − 22
Standard Test Method for
Comparing Bond Strength of Steel Reinforcing Bars to
1
Concrete Using Beam-End Specimens
This standard is issued under the fixed designation A944; 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 Scope*
1.1 This test method describes procedures to establish the relative bond strength of steel reinforcing bars in concrete.
1.2 This test method is intended to determine the effects of surface preparation or condition (such as bar coatings) on the bond
strength of deformed steel reinforcing bars (of sizes ranging from No. 103 to No. 3611 [No. 310 to No. 11])36]) to concrete.
1.3 The bond strengths obtained using this test method are not directly applicable to the design of reinforced concrete members.
NOTE 1—The bond strengths obtained using this test method are generally higher than obtained in development or splice tests using beams with the same
embedment lengths. The results obtained using this test method should only be used for comparisons with results for other reinforcing bars tested using
this method.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in brackets are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.5 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.6 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.
2. Referenced Documents
2
2.1 ASTM Standards:
A775/A775M Specification for Epoxy-Coated Steel Reinforcing Bars
C192/C192M Practice for Making and Curing Concrete Test Specimens in the Laboratory
E4 Practices for Force Calibration and Verification of Testing Machines
E575 Practice for Reporting Data from Structural Tests of Building Constructions, Elements, Connections, and Assemblies
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
1
This test method is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.05
on Steel Reinforcement.
Current edition approved Nov. 1, 2015Sept. 1, 2022. Published November 2015November 2022. Originally approved in 1995. Last previous edition approved in 20102015
as A944 – 10.A944 – 10 (2015). DOI: 10.1520/A0944-10R15.10.1520/A0944-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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A944 − 22
3.1.1 bond strength, n—maximum measured load in a tensile bond test of a steel reinforcing bar.
3.1.2 bonded length, n—the length of the test bar that is in contact with concrete.
3.1.3 concrete cover, n—minimum distance between the surface of the test bar and the top or bottom of the test specimen.
3.1.4 embedment length, n—the distance from the surface of the concrete test specimen to the installed end of the steel reinforcing
bar. This equals the sum of the lead length and the bonded length.
3.1.5 lead length, n—the length of the test bar that is not in contact with concrete but is between the surface of the concrete test
specimen and the bonded length.
3.1.6 relative rib area, n—ratio of the projected rib area normal to bar axis to the product of the nominal bar perimeter and the
center-to-center rib spacing.
2

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A944 − 22
3.2 Symbols:
C = Concrete cover, mm [in.].in. [mm].
bc
d = Nominal diamet
...