ASTM D7234-21

Standard Test Method for Pull-Off Adhesion Strength of Coatings on Concrete Using Portable Pull-Off Adhesion Testers

SIGNIFICANCE AND USE
5.1 The pull-off adhesion strength and mode of failure of a coating from a concrete substrate are important performance properties that are used in specifications. This test method serves as a means for uniformly preparing and testing coated surfaces, and evaluating and reporting the results.  
5.2 Variations in strength results obtained using different instruments, different substrates, or different loading fixtures with the same coating are possible. Therefore, it is recommended that the specific test instrument and loading fixture be mutually agreed upon between the interested parties.  
5.3 It is recommended that the coating be sufficiently cured to ensure cohesive strength and adhesion. This required minimum cure time before testing should be provided by the coating manufacturer, and may require an extension due to atmospheric conditions on site (for example, low temperature, and low or high humidity).  
5.4 This test method may be adapted to determine surface strength of uncoated concrete (see X2.1). Test Method C1583 is also suitable for that determination.  
5.5 The objective of this method is to determine the adhesion of a coating to concrete (or adapted for surface strength as stated in 5.4) and will result in failure in the coating or near the substrate surface. If evaluating the cohesive strength of the substrate or cementitious surfacers is the purpose of the testing, or if the substrate or cementitious surfacers have low strength, then Test Method C1583 may be more suitable.
SCOPE
1.1 This test method covers procedures for evaluating the pull-off adhesion strength of a coating on concrete. The test determines the greatest perpendicular force (in tension) that a surface area can bear before a plug of material is detached. Failure will occur along the weakest plane within the system comprised of the loading fixture, glue, coating system, and substrate, and will be exposed by the fracture surface.  
1.2 This test method uses a class of apparatus known as portable pull-off adhesion testers.2 They are capable of applying a concentric load and counter load to a single surface so that coatings can be tested even though only one side is accessible. Measurements are limited by the strength of adhesion bonds between the loading fixture, coating system and the substrate or the cohesive strengths of the glue, coating layers, and substrate.  
1.3 This test method is suitable for both laboratory and field testing.  
1.4 Pull-off adhesion strength measurements depend upon both material and instrumental parameters. There are different instruments used that comply with this test method. The specific instrument used should be identified when reporting results. This test is destructive and spot repairs may be necessary.  
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.6 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.  
1.7 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: Historical
• Publication Date: 30-Jun-2021
• ICS: 91.080.40 - Concrete structures
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.46 - Industrial Protective Coatings

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D7234 − 21
Standard Test Method for
Pull-Off Adhesion Strength of Coatings on Concrete Using
1
Portable Pull-Off Adhesion Testers
This standard is issued under the fixed designation D7234; 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 1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This test method covers procedures for evaluating the
ization established in the Decision on Principles for the
pull-off adhesion strength of a coating on concrete. The test
Development of International Standards, Guides and Recom-
determines the greatest perpendicular force (in tension) that a
mendations issued by the World Trade Organization Technical
surface area can bear before a plug of material is detached.
Barriers to Trade (TBT) Committee.
Failure will occur along the weakest plane within the system
comprised of the loading fixture, glue, coating system, and
2. Referenced Documents
substrate, and will be exposed by the fracture surface.
3
2.1 ASTM Standards:
1.2 This test method uses a class of apparatus known as
C1583 Test Method for Tensile Strength of Concrete Sur-
2
portable pull-off adhesion testers. They are capable of apply-
faces and the Bond Strength or Tensile Strength of
ing a concentric load and counter load to a single surface so
Concrete Repair and Overlay Materials by Direct Tension
that coatings can be tested even though only one side is
(Pull-off Method)
accessible. Measurements are limited by the strength of adhe-
D16 TerminologyforPaint,RelatedCoatings,Materials,and
sion bonds between the loading fixture, coating system and the
Applications
substrate or the cohesive strengths of the glue, coating layers,
D2651 GuideforPreparationofMetalSurfacesforAdhesive
and substrate.
Bonding
1.3 This test method is suitable for both laboratory and field
D3933 Guide for Preparation of Aluminum Surfaces for
testing.
Structural Adhesives Bonding (Phosphoric Acid Anodiz-
ing)
1.4 Pull-off adhesion strength measurements depend upon
D4541 Test Method for Pull-Off Strength of Coatings Using
both material and instrumental parameters. There are different
Portable Adhesion Testers
instruments used that comply with this test method. The
E177 Practice for Use of the Terms Precision and Bias in
specific instrument used should be identified when reporting
ASTM Test Methods
results. This test is destructive and spot repairs may be
E178 Practice for Dealing With Outlying Observations
necessary.
E691 Practice for Conducting an Interlaboratory Study to
1.5 The values stated in SI units are to be regarded as the
Determine the Precision of a Test Method
standard. The values given in parentheses are for information
only.
3. Terminology
1.6 This standard does not purport to address all of the
3.1 The terms and definitions in Terminology D16 apply to
safety concerns, if any, associated with its use. It is the
this test method.
responsibility of the user of this standard to establish appro-
3.2 Definitions:
priate safety, health, and environmental practices and deter-
3.2.1 concrete, n—with respect to this test method, refers to
mine the applicability of regulatory limitations prior to use.
all forms of concrete including masonry units.
3.2.2 glue, n—with respect to this test method, glue refers to
the material that bonds the bottom of the loading fixture to the
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint
top surface of the coating to be tested.
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.46 on Industrial Protective Coatings.
Current edition approved July 1, 2021. Published August 2021. Originally
3
approved in 2005. Last previous edition approved in 2019 as D7234 – 19. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/D7234-21. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
2
The term adhesion tester may be somewhat of a misnomer, but its adoption by Standards volume information, refer to the standard’s Document Summary page on
two manufacturers and at least two patents indicates continued usage. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D7234 − 21
3.2.3 loading fixture, n—(also referred to as dollies or studs) 6. Apparatus
a metal structure that is flat on one end for bonding to the
6.1 Adhesion Tester, including the components and accesso-
coa
...

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: D7234 − 19 D7234 − 21
Standard Test Method for
Pull-Off Adhesion Strength of Coatings on Concrete Using
1
Portable Pull-Off Adhesion Testers
This standard is issued under the fixed designation D7234; 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 test method covers procedures for evaluating the pull-off adhesion strength of a coating on concrete. The test determines
the greatest perpendicular force (in tension) that a surface area can bear before a plug of material is detached. Failure will occur
along the weakest plane within the system comprised of the loading fixture, glue, coating system, and substrate, and will be
exposed by the fracture surface.
2
1.2 This test method uses a class of apparatus known as portable pull-off adhesion testers. They are capable of applying a
concentric load and counter load to a single surface so that coatings can be tested even though only one side is accessible.
Measurements are limited by the strength of adhesion bonds between the loading fixture, coating system and the substrate or the
cohesive strengths of the glue, coating layers, and substrate.
1.3 This test method is suitable for both laboratory and field testing.
1.4 Pull-off adhesion strength measurements depend upon both material and instrumental parameters. There are different
instruments used that comply with this test method. The specific instrument used should be identified when reporting results. This
test is destructive and spot repairs may be necessary.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.6 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.
1.7 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
3
2.1 ASTM Standards:
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.46 on Industrial Protective Coatings.
Current edition approved Dec. 1, 2019July 1, 2021. Published January 2020August 2021. Originally approved in 2005. Last previous edition approved in 20122019 as
D7234 – 12.D7234 – 19. DOI: 10.1520/D7234-19.10.1520/D7234-21.
2
The term adhesion tester may be somewhat of a misnomer, but its adoption by two manufacturers and at least two patents indicates continued usage.
3
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D7234 − 21
C1583 Test Method for Tensile Strength of Concrete Surfaces and the Bond Strength or Tensile Strength of Concrete Repair and
Overlay Materials by Direct Tension (Pull-off Method)
D16 Terminology for Paint, Related Coatings, Materials, and Applications
D2651 Guide for Preparation of Metal Surfaces for Adhesive Bonding
D3933 Guide for Preparation of Aluminum Surfaces for Structural Adhesives Bonding (Phosphoric Acid Anodizing)
D4541 Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E178 Practice for Dealing With Outlying Observations
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 The terms and definitions in Terminology D16 apply to this test method.
3.2 Definitions:
3.2.1 concrete, n—with respect to this test method, refers to all forms of concrete including masonry units.
3.2.2 glue, n—(withwith
...