ASTM D4260-23

Standard Practice for Liquid and Gelled Acid Etching of Concrete

SIGNIFICANCE AND USE
5.1 This practice is used to prepare concrete for coatings where optimum bond is desired for service conditions such as continuous or intermittent immersion, temperature cycling, or mechanical loading.
SCOPE
1.1 This practice covers surface preparation of concrete to prepare the surface prior to the application of coatings.  
1.2 This practice is intended to alter the surface profile of the concrete and to remove foreign materials and weak surface laitance.  
1.3 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. For specific hazard statements, see Section 6.  
1.4 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-Mar-2023
• ICS: 91.080.40 - Concrete structures
• Technical Committee: D33 - Protective Coating and Lining Work for Power Generation Facilities
• Drafting Committee: D33.05 - Application and Surface Preparation

Relations

• Refers: ASTM D4259-18 - Standard Practice for Preparation of Concrete by Abrasion Prior to Coating Application
• Effective Date: 15-Dec-2018
• Refers: ASTM D4262-05(2018) - Standard Test Method for pH of Chemically Cleaned or Etched Concrete Surfaces
• Effective Date: 01-Aug-2018
• Refers: ASTM D4263-83(2018) - Standard Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method
• Effective Date: 01-Aug-2018
• Refers: ASTM D4263-83(2012) - Standard Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method
• Effective Date: 01-May-2012
• Refers: ASTM D4259-88(2012) - Standard Practice for Abrading Concrete
• Effective Date: 01-May-2012
• Refers: ASTM D4262-05(2012) - Standard Test Method for pH of Chemically Cleaned or Etched Concrete Surfaces
• Effective Date: 01-May-2012
• Refers: ASTM D4258-05(2012) - Standard Practice for Surface Cleaning Concrete for Coating
• Effective Date: 01-May-2012
• Refers: ASTM D4541-09 - Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers
• Effective Date: 01-Feb-2009
• Refers: ASTM D4259-88(2006) - Standard Practice for Abrading Concrete
• Effective Date: 01-Dec-2006
• Refers: ASTM D4263-83(2005) - Standard Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method
• Effective Date: 01-Sep-2005
• Refers: ASTM D4258-05 - Standard Practice for Surface Cleaning Concrete for Coating
• Effective Date: 01-Sep-2005
• Refers: ASTM D4262-05 - Standard Test Method for pH of Chemically Cleaned or Etched Concrete Surfaces
• Effective Date: 01-Mar-2005
• Refers: ASTM D4541-02 - Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers
• Effective Date: 10-Feb-2002
• Refers: ASTM D4541-95e1 - Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers
• Effective Date: 10-Feb-2002
• Refers: ASTM D4263-83(1999) - Standard Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method
• Effective Date: 10-Feb-1999

Overview

ASTM D4260-23: Standard Practice for Liquid and Gelled Acid Etching of Concrete outlines best practices for the surface preparation of concrete prior to the application of protective coatings. This standard, developed by ASTM International, details procedures for using both liquid and gelled acid etching methods to achieve optimal coating adhesion under demanding service conditions, such as immersion, temperature cycling, or mechanical loading. By establishing thorough requirements, ASTM D4260-23 ensures the removal of surface contaminants, weak laitance, and establishes a uniform surface profile, ready for subsequent coating applications.

Key Topics

• Surface Preparation Methods: Covers procedures for both liquid acid and gelled acid etching to clean and roughen concrete surfaces.
• Surface Conditions: Specifies requirements for removing laitance, form release agents, curing compounds, oils, grease, and other contaminants.
• Etching Procedures: Differentiates methods aimed at horizontal (liquid acid) vs. horizontal, vertical, or overhead surfaces (gelled acid).
• Curing and Pre-Cleaning: Emphasizes proper concrete curing as per ACI-308 and initial cleaning (ASTM D4258) for optimal etching.
• Inspection and Acceptance: Details visual and physical inspection criteria after etching, including pH and roughness.
• Safety and Compliance: Highlights the responsibility to follow safety, health, environmental, and regulatory practices when using acid solutions.

Applications

ASTM D4260-23 provides significant value in concrete construction and maintenance, especially in environments or projects requiring high-performance coatings with durable adhesion:

• Coating Preparation: Ensures surfaces are adequately roughened and free of contaminants to support protective coatings in water and wastewater facilities, power plants, and industrial settings.
• Surface Profile Control: Enables contractors to achieve a specific texture and cleanliness, important for coatings subjected to harsh service, such as mechanical loading, immersion, or thermal cycling.
• Versatile Use Cases: The standard covers both new and existing concrete, as well as various applications-from floors and containment areas to vertical walls and overhead structures.
• Inspection Support: Establishes a framework for verifying surface readiness, minimizing coating failures due to poor substrate preparation.
• Quality Assurance: Helps facility owners, specifiers, and contractors achieve consistent, reproducible surface conditions for reliable coating performance.

Related Standards

ASTM D4260-23 references and complements several other standards relevant to concrete surface preparation and treatment:

• ASTM D4258: Practice for Surface Cleaning Concrete for Coating - addresses preliminary cleaning of oil, grease, and contaminants.
• ASTM D4259: Practice for Preparation of Concrete by Abrasion Prior to Coating Application - describes mechanical and abrasive cleaning methods.
• ASTM D4262: Test Method for pH of Chemically Cleaned or Etched Concrete Surfaces - used for confirming neutralization after acid etching.
• ASTM D4263: Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method - assists in ensuring surfaces are suitably dry before coating.
• ASTM D4541: Test Method for Pull-Off Strength of Coatings - verifies bond strength where specified.
• ACI-308: Guide to Curing Concrete - referenced for proper curing practices before etching.

By following ASTM D4260-23, stakeholders in concrete surface preparation can achieve a consistent, high-quality foundation for coating systems, optimizing the performance and life expectancy of protective treatments in industrial and commercial environments.

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: D4260 − 23
Standard Practice for
Liquid and Gelled Acid Etching of Concrete
This standard is issued under the fixed designation D4260; 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 3. Terminology
1.1 This practice covers surface preparation of concrete to 3.1 Definitions of Terms Specific to This Standard:
prepare the surface prior to the application of coatings. 3.1.1 gelled acid, n—acid solution primarily intended for
use on horizontal, vertical, and overhead surfaces.
1.2 This practice is intended to alter the surface profile of
3.1.2 liquid acid, n—acid solution primarily intended for
the concrete and to remove foreign materials and weak surface
use on horizontal surfaces.
laitance.
1.3 This standard does not purport to address all of the
4. Summary of Practice
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 4.1 This practice is intended to provide a clean,
priate safety, health, and environmental practices and deter- contamination-free, and roughened surface.
mine the applicability of regulatory limitations prior to use.
4.2 Acceptable surfaces shall be free of laitance, form
For specific hazard statements, see Section 6.
release agents, curing agents, oil, grease, and other penetrating
1.4 This international standard was developed in accor-
contaminants. The surface shall be free of fins, projections, and
dance with internationally recognized principles on standard-
loosely adhering concrete, dirt, and dust particles.
ization established in the Decision on Principles for the
4.3 For some applications, a minimum concrete surface
Development of International Standards, Guides and Recom-
strength may be required for proper coating performance.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
5. Significance and Use
2. Referenced Documents
5.1 This practice is used to prepare concrete for coatings
where optimum bond is desired for service conditions such as
2.1 ASTM Standards:
continuous or intermittent immersion, temperature cycling, or
D4258 Practice for Surface Cleaning Concrete for Coating
mechanical loading.
D4259 Practice for Preparation of Concrete by Abrasion
Prior to Coating Application
6. Hazards
D4262 Test Method for pH of Chemically Cleaned or Etched
Concrete Surfaces
6.1 Use and disposal of materials should conform to estab-
D4263 Test Method for Indicating Moisture in Concrete by
lished federal, state, local, and project requirements.
the Plastic Sheet Method
METHOD A
D4541 Test Method for Pull-Off Strength of Coatings Using
Portable Adhesion Testers
7. Liquid Acid Etching Procedure
2.2 Other Standard:
ACI-308 Guide to Curing Concrete
7.1 Pre-Surface Preparation:
7.1.1 New concrete shall be cured in accordance with
ACI-308.
This practice is under the jurisdiction of ASTM Committee D33 on Protective
7.1.2 Remove grease, oil, and other penetrating contami-
Coating and Lining Work for Power Generation Facilities and is the direct
responsibility of Subcommittee D33.05 on Application and Surface Preparation.
nants (see Practice D4258).
Current edition approved April 1, 2023. Published April 2023. Originally
7.1.3 Remove fins and protruding surface irregularities by
approved in 1983. Last previous edition approved in 2017 as D4260 – 05 (2017).
mechanical means.
DOI: 10.1520/D4260-23.
7.1.4 Surfaces shall be free of standing water.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
7.1.5 Some curing compounds may not be removed by
Standards volume information, refer to the standard’s Document Summary page on
liquid acid etching and will require preparation by mechanical
the ASTM website.
abrading, abrasive blasting, or water blasting in accordance
Available from American Concrete Institute (ACI), P.O. Box 9094, Farmington
Hills, MI 48333-9094, http://www.concrete.org. with Practice D4259.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4260 − 23
7.1.6 When using liquid acid, proper cross ventilation and 8.2 Suitable Surfaces:
chemical respirators shall be provided. 8.2.1 This method is suited for use on horizontal, vertical,
and overhead surfaces.
7.2 Suitable Surfaces:
8.2.2 Other means of preparation may be more suitable for
7.2.1 This method is primarily suited for use on horizontal
rough concrete surfaces.
surfaces.
7.2.2 Other methods of preparation may be more suitable 8.3 Gelled Acid Etching Solutions:
for rough concrete surfaces and walls or overhead surfaces.
8.3.1 Typical solutions covered by this method are muriatic
(hydrochloric), sulfamic, phosphoric and citric acids. Hydro-
7.3 Liquid Acid Etching Solutions:
chloric acid shall not be used where chlorides are prohibited.
7.3.1 Typical solutions covered by this method are muriatic
8.3.2 The gelled acid concentrations of etching solutions
(hydrochloric), sulfamic, phosphoric and citric acids. Hydro-
may vary depending on the concrete texture and the degree of
chloric acid shall not be used where chlorides are prohibited.
etching required.
7.3.2 The liquid acid concentrations of etching solutions
8.3.3 The concrete surface can be pre-wetted with water
may vary, depending on the concrete texture and degree of
prior to applying etching solutions. Free-standing water shall
etching required.
be removed. Uniformly apply the etching solution to the wet
7.3.3 The concrete surface shall be pre-wett
...

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: D4260 − 05 (Reapproved 2017) D4260 − 23
Standard Practice for
Liquid and Gelled Acid Etching of Concrete
This standard is issued under the fixed designation D4260; 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 practice covers surface preparation of concrete to prepare the surface prior to the application of coatings.
1.2 This practice is intended to alter the surface profile of the concrete and to remove foreign materials and weak surface laitance.
1.3 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. For specific hazard statements, see Section 6.
1.4 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
2.1 ASTM Standards:
D4258 Practice for Surface Cleaning Concrete for Coating
D4259 Practice for Preparation of Concrete by Abrasion Prior to Coating Application
D4262 Test Method for pH of Chemically Cleaned or Etched Concrete Surfaces
D4263 Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method
D4541 Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers
2.2 Other Standard:
ACI-308 Guide to Curing Concrete
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 gelled acid, n—acid solution primarily intended for use on horizontal, vertical, and overhead surfaces.
3.1.2 liquid acid, n—acid solution primarily intended for use on horizontal surfaces.
4. Summary of Practice
4.1 This practice is intended to provide a clean, contamination-free, and roughened surface.
This practice is under the jurisdiction of ASTM Committee D33 on Protective Coating and Lining Work for Power Generation Facilities and is the direct responsibility
of Subcommittee D33.05 on Application and Surface Preparation.
Current edition approved Sept. 1, 2017April 1, 2023. Published September 2017April 2023. Originally approved in 1983. Last previous edition approved in 20122017 as
D4260 – 05 (2012).(2017). DOI: 10.1520/D4260-05R17.10.1520/D4260-23.
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.
Available from American Concrete Institute (ACI), P.O. Box 9094, Farmington Hills, MI 48333-9094, http://www.concrete.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4260 − 23
4.2 Acceptable surfaces shall be free of laitance, form release agents, curing agents, oil, grease, and other penetrating
contaminants. The surface shall be free of fins, projections, and loosely adhering concrete, dirt, and dust particles.
4.3 For some applications, a minimum concrete surface strength may be required for proper coating performance.
5. Significance and Use
5.1 This practice is used to prepare concrete for coatings where optimum bond is desired for service conditions such as continuous
or intermittent immersion, temperature cycling, or mechanical loading.
6. Hazards
6.1 New concrete shall be cured in accordance with ACI-308.
6.2 Concrete cure compounds, form release materials, or concrete hardeners may require abrading, in accordance with Practice
D4259, as acid etching may not be effective.
6.3 All oil and grease shall be removed in accordance with Practice D4258 prior to mechanical abrading, abrasive blast cleaning,
water blasting, or acid etching.
6.1 Use and disposal of materials should conform to established federal, state, local, and project requirements.
METHOD A
7. Liquid Acid Etching Procedure
7.1 Pre-Surface Preparation:
7.1.1 New concrete shall be cured in accordance with ACI-308.
7.1.2 Remove grease, oil, and other penetrating contaminants (see Practice D4258).
7.1.3 Remove fins and protruding surface irregularities by mechanical means.
7.1.4 Surfaces shall be free of standing water.
7.1.5 Some curing compounds may not be removed by liquid acid etching and will require preparation by mechanical abrading,
abrasive blasting, or water blasting in accordance with Practice D4259.
7.1.6 When using liquid acid, proper cross ventilation and chemical respirators shall be provided.
7.2 Suitable Surfaces:
7.2.1 This method is primarily suited for use on horizontal surfaces.
7.2.2 Other methods of preparation may be more suitable for rough concrete surfaces and walls or overhead surfaces.
7.3 Liquid Acid Etching Solutions:
7.3.1 Typical solutions covered by this method are muriatic (hydrochloric), sulfamic, phosphoric and citric acids. Hydrochloric
acid shall not be used where chlorides are prohibited.
7.3.2 The liquid acid concentrations of etching solutions may vary, depending on the concrete texture and degree of etching
required.
D4260 − 23
7.3.3 The concrete surface shall be pre-wetted with water prior to applying etching solutions. Free-standing water shall be
removed. Uniformly apply the etching solution to the wet surface. Polyethylene sprinkling cans are suitable for applying liquid
acid solutions. Bubbling should be uniformly evident. If not, this indicates the presence of grease or oil contamination, or both,
curing compounds or sealers, or a need to increas
...