ASTM G180-23

Standard Test Method for Corrosion Inhibiting Admixtures for Steel in Concrete by Polarization Resistance in Cementitious Slurries

SIGNIFICANCE AND USE
4.1 This test method provides a means for assessing corrosion-inhibiting concrete admixtures.  
4.2 This test method is useful for development of admixtures intended to reduce corrosion of reinforcing steel in concrete.  
4.3 This test method is useful in determining the corrosivity of admixtures toward steel reinforcing if the admixture sample is compared to a control without admixtures.  
4.4 Good performance, a reduction in corrosion rate versus chloride alone by at least one order of magnitude in this test, is a strong indication that an admixture is a corrosion inhibitor. However, poor performance requires additional testing to determine if the admixture improves corrosion resistance.  
4.5 This test method shall not be used to predict performance in the field.  
4.6 The filtering process makes this test not suitable for the evaluation of emulsions.
SCOPE
1.1 This test method covers a procedure for determining the effects of chemical admixtures on the corrosion of metals in concrete. This test method can be used to evaluate materials intended to inhibit chloride-induced corrosion of steel in concrete. It can also be used to evaluate the corrosivity of admixtures by themselves or in a chloride environment. This test is not applicable for emulsions.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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.  
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-May-2023
• ICS: 77.140.15 - Steels for reinforcement of concrete
• Technical Committee: G01 - Corrosion of Metals
• Drafting Committee: G01.14 - Corrosion of Metals in Construction Materials

Relations

• Refers: ASTM C670-24a - Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
• Effective Date: 01-Feb-2024
• Refers: ASTM C670-24 - Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM G3-14(2019) - Standard Practice for Conventions Applicable to Electrochemical Measurements in Corrosion Testing
• Effective Date: 01-May-2019
• Refers: ASTM C150/C150M-19 - Standard Specification for Portland Cement
• Effective Date: 01-Apr-2019
• Refers: ASTM C595/C595M-17 - Standard Specification for Blended Hydraulic Cements
• Effective Date: 01-Apr-2017
• Refers: ASTM C150/C150M-16 - Standard Specification for Portland Cement
• Effective Date: 15-Mar-2016
• Refers: ASTM C595/C595M-15 - Standard Specification for Blended Hydraulic Cements
• Effective Date: 01-Jul-2015
• Refers: ASTM C150/C150M-15 - Standard Specification for Portland Cement
• Effective Date: 01-Jul-2015
• Refers: ASTM G3-14 - Standard Practice for Conventions Applicable to Electrochemical Measurements in Corrosion Testing
• Effective Date: 15-Dec-2014
• Refers: ASTM G5-14 - Standard Reference Test Method for Making Potentiodynamic Anodic Polarization Measurements
• Effective Date: 01-Nov-2014
• Refers: ASTM C595/C595M-14 - Standard Specification for Blended Hydraulic Cements
• Effective Date: 01-May-2014
• Refers: ASTM G3-13 - Standard Practice for Conventions Applicable to Electrochemical Measurements in Corrosion Testing
• Effective Date: 01-Dec-2013
• Refers: ASTM C670-13 - Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
• Effective Date: 01-Jul-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM C595/C595M-13 - Standard Specification for Blended Hydraulic Cements
• Effective Date: 01-Mar-2013

Overview

ASTM G180-23: Standard Test Method for Corrosion Inhibiting Admixtures for Steel in Concrete by Polarization Resistance in Cementitious Slurries provides a reliable lab-based method for assessing the effectiveness of chemical admixtures designed to inhibit corrosion of reinforcing steel in concrete. Developed by ASTM International, this standard outlines a procedure using polarization resistance measurements in cementitious slurries to gauge how admixtures impact steel corrosion rates, especially in chloride-rich environments. ASTM G180-23 is a critical tool for researchers, admixture manufacturers, and construction professionals aiming to enhance the long-term durability of reinforced concrete structures.

Key Topics

• Corrosion Inhibition Assessment: The test offers a comparative analysis of corrosion rates for reinforcing steel in the presence and absence of admixtures, particularly in the context of chloride-induced corrosion.

• Development and Screening: The method supports the development and initial screening of admixtures meant to reduce corrosion of steel reinforcement in concrete.

• Testing Scope and Limitations:

  • Suitable for admixtures in cement slurries but not appropriate for emulsions due to incompatibility with filtration steps.
  • The method is designed for laboratory evaluation and should not be used to predict in-field performance of admixtures.
  • Requires comparison to a control sample to determine relative corrosivity or corrosion-inhibiting properties.

• Result Interpretation:

  • A significant reduction in corrosion rate (by at least one order of magnitude versus chloride-only) is considered strong evidence of corrosion inhibition.
  • Subpar results warrant further testing with other methods to determine the admixture’s efficacy.

Applications

ASTM G180-23 is widely applicable to:

• Admixture Development: Manufacturers can screen new products for corrosion inhibition effectiveness in a controlled laboratory environment before moving to more comprehensive field trials or broader commercial use.
• Quality Control: The method helps admixture suppliers validate claims regarding corrosion inhibition and assure clients of material performance.
• Materials Characterization: Research and development teams use this test to compare the corrosivity of new admixtures or optimize existing formulations for improved protective properties.
• Academic Research: Universities and research institutions rely on standardized testing for publishing results and comparing data across different studies.

Typical users include:

• Concrete admixture manufacturers
• Construction material testing laboratories
• Structural engineers and consultants
• Academic researchers in civil engineering and materials science

Related Standards

Several other ASTM standards are referenced or used in conjunction with ASTM G180-23, supporting broader corrosion testing and cement materials analysis:

• ASTM C150/C150M: Specification for Portland Cement
• ASTM C595/C595M: Specification for Blended Hydraulic Cements
• ASTM D632: Specification for Sodium Chloride
• ASTM G5: Reference Test Method for Making Potentiodynamic Anodic Polarization Measurements
• ASTM G59: Test Method for Conducting Potentiodynamic Polarization Resistance Measurements
• ASTM G3 and G193: Practice for Conventions and Terminology Related to Corrosion

ASTM G180-23 aligns with international principles by following the WTO Technical Barriers to Trade (TBT) Committee recommendations, ensuring global relevance and industry acceptance.

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By specifying a consistent, reproducible laboratory protocol for measuring corrosion inhibition in cementitious slurries, ASTM G180-23 helps drive innovation, quality, and durability in reinforced concrete construction, supporting infrastructure longevity worldwide.

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: G180 − 23
Standard Test Method for
Corrosion Inhibiting Admixtures for Steel in Concrete by
Polarization Resistance in Cementitious Slurries
This standard is issued under the fixed designation G180; 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 G3 Practice for Conventions Applicable to Electrochemical
Measurements in Corrosion Testing
1.1 This test method covers a procedure for determining the
G5 Reference Test Method for Making Potentiodynamic
effects of chemical admixtures on the corrosion of metals in
Anodic Polarization Measurements
concrete. This test method can be used to evaluate materials
G59 Test Method for Conducting Potentiodynamic Polariza-
intended to inhibit chloride-induced corrosion of steel in
tion Resistance Measurements
concrete. It can also be used to evaluate the corrosivity of
G193 Terminology and Acronyms Relating to Corrosion
admixtures by themselves or in a chloride environment. This
test is not applicable for emulsions.
3. Terminology
1.2 The values stated in SI units are to be regarded as
3.1 Definitions—For definitions of terms used in this prac-
standard. No other units of measurement are included in this
tice see Terminology G193.
standard.
4. Significance and Use
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4.1 This test method provides a means for assessing
responsibility of the user of this standard to establish appro-
corrosion-inhibiting concrete admixtures.
priate safety, health, and environmental practices and deter-
4.2 This test method is useful for development of admix-
mine the applicability of regulatory limitations prior to use.
tures intended to reduce corrosion of reinforcing steel in
1.4 This international standard was developed in accor-
concrete.
dance with internationally recognized principles on standard-
4.3 This test method is useful in determining the corrosivity
ization established in the Decision on Principles for the
of admixtures toward steel reinforcing if the admixture sample
Development of International Standards, Guides and Recom-
is compared to a control without admixtures.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4.4 Good performance, a reduction in corrosion rate versus
chloride alone by at least one order of magnitude in this test, is
2. Referenced Documents
a strong indication that an admixture is a corrosion inhibitor.
2.1 ASTM Standards: However, poor performance requires additional testing to
C150/C150M Specification for Portland Cement determine if the admixture improves corrosion resistance.
C595/C595M Specification for Blended Hydraulic Cements
4.5 This test method shall not be used to predict perfor-
C670 Practice for Preparing Precision and Bias Statements
mance in the field.
for Test Methods for Construction Materials
4.6 The filtering process makes this test not suitable for the
D632 Specification for Sodium Chloride
evaluation of emulsions.
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
5. Apparatus
5.1 The test cell as described in Reference Test Method G5.
This test method is under the jurisdiction of ASTM Committee G01 on
5.2 Potentiostat, as described in Reference Test Method G5,
Corrosion of Metals and is the direct responsibility of Subcommittee G01.14 on
capable of varying potential at a constant scan rate and
Corrosion of Metals in Construction Materials.
Current edition approved June 1, 2023. Published June 2023. Originally measuring the resulting current.
approved in 2004. Last previous edition approved in 2021 as G180 – 21. DOI:
5.3 A method of recording the varying potential and result-
10.1520/G0180-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or ing current is needed.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
5.4 Electrode holder such as described in Fig. 3 of Refer-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. ence Test Method G5.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G180 − 23
NOTE 3—This process removes machine oils and inhibitors that might
5.5 Electrodes:
be on the surface due to packaging.
5.5.1 Working electrode, prepared from a 12.7 mm length of
9.5 mm diameter rod stock. Carbon steel C1215 should be 7.5 While purging the cell with carbon dioxide free air,
used. precondition the electrode in the solution for 24 h.
7.5.1 Add NaCl to the solution obtained in 7.3 (having been
NOTE 1—If specimen forms are used other than those called for by this
purged for 24 h with CO -free air), to obtain a 0.5M or a 1M
test method, for example flat sheet specimens, care should be taken not to
solution, and continue to stir and purge for a further 4 h. After
introduce crevices which can lead to erroneous results.
4 h, stop stirring and continue purging for another 20 h.
5.6 Auxiliary Electrodes—Two graphite rods or platinized-
niobium or platinum mesh.
NOTE 4—The multi-laboratory test was run at the two different chloride
levels to develop the precision statement. The higher chloride level would
5.7 Reference Electrodes—A saturated calomel electrode
be representative of a more severe exposure.
with a controlled rate of leakage (about 3 μL/h) is recom-
7.5.2 Measure the open circuit potential.
mended.
7.5.3 Measure the polarization resistance (R ) by recording
p
6. Reagents and Materials the potentiodynamic polarization curve at a scan rate of
0.167 mV ⁄s, from –20 mV to +20 mV versus open circuit
6.1 Type I/II cement (C3A content between 6 % and 10 %),
potential.
according to Specification C150/C150M, or a Type 1L cement
7.5.4 Plot the polarization resistance curve as a linear
(portland-limestone cement) according to Specification C595/
potential-current density plot as shown in Practice G3.
C595M.
7.5.5 Determine the polarization resistance R , as the tan-
p
6.2 Filter paper with 1.1 μm retention.
gent of the curve at i = 0, as described in Test Method G59. The
corrosion rate is expressed as 1/R in μS/cm .
6.3 PTFE stir bars.
p
6.4 Carbon steel C1215 samples, cylindrical in shape, with NOTE 5—An example of a polarization resistance curve is given in Fig.
2 3
X1.4.
5.1 cm exposed area.
6.5 Sodium chloride, reagent grade, according to Specifica-
8. Interpretation of Results
tion D632.
8.1 An admixture is behaving as a corrosion inhibitor in this
6.6 Calcium hydroxide, reagent grade.
test method if the average log (1/R ) value is 1.0 or less than
10 p
that of the chloride only average.
6.7 Admixtures to be tested.
8.2 If the admixture does not reduce average 1/R by an
6.8 Carbon-dioxide-free compressed air.
p
order of magnitude another test method is needed to determine
7. Experimental Procedure
if it is an inhibitor.
7.1 Prepare a cement slurry consisting of 1000 g of water
8.3 An admixture that increases average 1/R by an order of
p
and 200 g cement. Mix thoroughly, stir for 60 min, and filter.
magnitude over a slurry without chloride or inhibitor is
NOTE 2—An admixture should be added at a quantity consistent with its
corrosive.
addition rate in concrete. Water measured at 35 mL to 965 mL is
NOTE 6—The change in log (1/R ) by 1.0 is an order of magnitude
10 p
equivalent to 5 L/m in concrete. If other dosages are desired, proportion
change in 1/R . Log values are useful in comparing corrosion rates since
p
them based on this ratio.
rates from different specimens or conditions can differ by orders of
magnitude making a linear scale less useful.
7.2 Filter, and add 4 g/L calcium hydroxide and stir a further
30 min.
9. Report
7.3 Set up a standard electrochemical cell according to
9.1 Report the following information:
Referen
...

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: G180 − 21 G180 − 23
Standard Test Method for
Corrosion Inhibiting Admixtures for Steel in Concrete by
Polarization Resistance in Cementitious Slurries
This standard is issued under the fixed designation G180; 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 a procedure for determining the effects of chemical admixtures on the corrosion of metals in concrete.
This test method can be used to evaluate materials intended to inhibit chloride-induced corrosion of steel in concrete. It can also
be used to evaluate the corrosivity of admixtures by themselves or in a chloride environment. This test is not applicable for
emulsions.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.
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:
C150/C150M Specification for Portland Cement
C595/C595M Specification for Blended Hydraulic Cements
C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
D632 Specification for Sodium Chloride
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
G3 Practice for Conventions Applicable to Electrochemical Measurements in Corrosion Testing
G5 Reference Test Method for Making Potentiodynamic Anodic Polarization Measurements
G59 Test Method for Conducting Potentiodynamic Polarization Resistance Measurements
G193 Terminology and Acronyms Relating to Corrosion
3. Terminology
3.1 Definitions—For definitions of terms used in this practice see Terminology G193.
This test method is under the jurisdiction of ASTM Committee G01 on Corrosion of Metals and is the direct responsibility of Subcommittee G01.14 on Corrosion of
Metals in Construction Materials.
Current edition approved April 1, 2021June 1, 2023. Published April 2021June 2023. Originally approved in 2004. Last previous edition approved in 20192021 as
G180 – 13 (2019).G180 – 21. DOI: 10.1520/G0180-21.10.1520/G0180-23.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G180 − 23
4. Significance and Use
4.1 This test method provides a means for assessing corrosion-inhibiting concrete admixtures.
4.2 This test method is useful for development of admixtures intended to reduce corrosion of reinforcing steel in concrete.
4.3 This test method is useful in determining the corrosivity of admixtures toward steel reinforcing if the admixture sample is
compared to a control without admixtures.
4.4 Good performance, a reduction in corrosion rate versus chloride alone by at least one order of magnitude in this test, is a strong
indication that an admixture is a corrosion inhibitor. However, poor performance requires additional testing to determine if the
admixture improves corrosion resistance.
4.5 This test method shall not be used to predict performance in the field.
4.6 The filtering process makes this test not suitable for the evaluation of emulsions.
5. Apparatus
5.1 The test cell as described in Reference Test Method G5.
5.2 Potentiostat, as described in Reference Test Method G5, capable of varying potential at a constant scan rate and measuring
the resulting current.
5.3 A method of recording the varying potential and resulting current is needed.
5.4 Electrode holder such as described in Fig. 3 of Reference Test Method G5.
5.5 Electrodes:
5.5.1 Working electrode, prepared from a 12.7 mm length of 9.5 mm diameter rod stock. Carbon steel C1215 should be used.
NOTE 1—If specimen forms are used other than those called for by this test method, for example flat sheet specimens, care should be taken not to introduce
crevices which can lead to erroneous results.
5.6 Auxiliary Electrodes—Two graphite rods or platinized-niobium or platinum mesh.
5.7 Reference Electrodes—A saturated calomel electrode with a controlled rate of leakage (about 3 μL/h) is recommended.
6. Reagents and Materials
6.1 Type I/II cement (C3A content between 6 % and 10 %), according to Specification C150/C150M, or a Type 1L cement
(portland-limestone cement) according to Specification C595/C595M.
6.2 Filter paper with 1.1 μm retention.
6.3 PTFE stir bars.
2 3
6.4 Carbon steel C1215 samples, cylindrical in shape, with 5.1 cm exposed area.
The sole source of supply of the apparatus known to the committee at this time is Metal Samples, AL, sample type P/N410. If you are aware of alternative suppliers,
please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee,
which you may attend.
G180 − 23
6.5 Sodium chloride, reagent grade, according to Specification D632.
6.6 Calcium hydroxide, reagent grade.
6.7 Admixtures to be tested.
6.8 Carbon dioxide free Carbon-dioxide-free compressed air.
7. Experimental Procedure
7.1 Prepare a cement slurry consisting of 1000 g of water and 200 g cement. Mix thoroughly, stir for 60 min, and filter.
NOTE 2—An admixture should be added at a quantity consistent with its addition rate in concrete. Water measured at 35 mL to 965 mL is equivalent to
5 L/m in concrete. If other dosages are desired, proportion them based on this ratio.
7.2 Filter, and add 4 g/L calcium hydroxide and stir a further 30 min.
7.3 Setup Set up a standard electrochemical cell according to Reference Test Method G5 and fill it with 900 mL of filtered slurry
solution. Purge the cell with carbon dioxide free air. Air flow carbon-dioxide-free air. Airflow rate should be at least 300 cc/min.
7.4 Specimen Preparation before Testing:
7.4.1 Degrease the metal sample by cleaning ultrasonically in hexane for 2 min. If an ultrasonic bath is not available, soak the
samples in hexane and wipe dry.
7.4.2 Wet abrade the specimen with 600 grit paper and rinse with deionized water.
7.4.3 Repeat 7.4.1. Make sure the sample is thoroughly dried before mounting it on the electrode holder.
NOTE 3—This process removes machine oils and inhibitors that might be on the surface due to packaging.
7.5 While purging the cell with carbon dioxide free air, precondition the electrode in the solution for 24 h.
7.5.1 Add NaCl to the solution obtained in 7.3 (having been purged for 24 h with CO -free air), to obtain a 0.50.5M or a 1M
solution, and continue to stir and purge for a further 4 h. After 4 h, stop stirring and continue purging for a another 20 h.
NOTE 4—The multi-laboratory test was run at the two different chloride levels to develop the precision statement. The higher chloride level would be
representative of a more severe exposure.
7.5.2 Measure the open circuit potential.
7.5.3 Measure the polarization resistance (R ) by recording the potentiodynamic polarization curve at a scan rate of 0.167 mV ⁄s,
p
from –20 mV to +20 mV versus open circuit potential.
7.5.4 Plot the polarization resistance curve as a linear potential-current density plot as shown in Practice G3.
7.
...