ASTM C1293/C1293M-23a

Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction

SIGNIFICANCE AND USE
4.1 Alkali-silica reaction is a chemical interaction between some siliceous constituents of concrete aggregates and hydroxyl ions (1).5 The concentration of hydroxyl ion within the concrete is predominantly controlled by the concentration of sodium and potassium (2).  
4.2 This test method is intended to evaluate the potential of an aggregate or combination of an aggregate with pozzolan or slag to expand deleteriously due to any form of alkali-silica reactivity (3, 4).  
4.3 If testing an aggregate with pozzolan or slag, the results are used to establish minimum amounts of the specific pozzolan or slag needed to prevent deleterious expansion. Pozzolan or slag from a specific source can be tested individually or in combination with pozzolan or slag from other sources.  
4.4 When selecting a sample or deciding on the number of samples for test, it is important to recognize the variability in lithology of material from a given source, whether a deposit of sand, gravel, or a rock formation of any origin. For specific advice, see Guide C295/C295M.  
4.5 This test method is intended for evaluating the behavior of aggregates in concrete with an alkali (alkali metal oxide) content of 5.25 kg/m3 [8.85 lb/yd3] or in concrete containing pozzolan or slag with an alkali content proportionally reduced from 5.25 kg/m3 [8.85 lb/yd3] Na2O equivalent by the amount of pozzolan or slag replacing portland cement or portland-limestone cement. This test method assesses the potential for deleterious expansion of concrete caused by alkali-silica reaction, of either coarse or fine aggregates, from tests performed under prescribed laboratory curing conditions that will probably differ from field conditions. Thus, actual field performance will not be duplicated due to differences in concrete alkali content, wetting and drying, temperature, other factors, or combinations of these (5).  
4.6 Results of tests conducted on an aggregate as described herein should form a part of the basis for a...
SCOPE
1.1 This test method covers the determination of the susceptibility of an aggregate or combination of an aggregate with pozzolan or slag for participation in expansive alkali-silica reaction by measurement of length change of concrete prisms.  
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as the 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.
Note 1: Sieve size is identified by its standard designation in Specification E11. The alternative designation given in parentheses is for information only and does not represent a different standard sieve size.  
1.3 The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.  
1.4 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. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure.2)  
1.5 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: 30-Nov-2023
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.50 - Aggregate Reactions in Concrete

Relations

• Replaces: ASTM C1293/C1293M-23 - Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction
• Effective Date: 01-Dec-2023
• Refers: ASTM C989/C989M-24 - Standard Specification for Slag Cement for Use in Concrete and Mortars
• Effective Date: 01-Feb-2024
• Refers: ASTM C1260-22 - Standard Test Method for Potential Alkali Reactivity of Aggregates (Mortar-Bar Method)
• Effective Date: 01-Nov-2022
• Refers: ASTM C989/C989M-22 - Standard Specification for Slag Cement for Use in Concrete and Mortars
• Effective Date: 01-Jul-2022
• Referred By: ASTM C1778-23 - Standard Guide for Reducing the Risk of Deleterious Alkali-Aggregate Reaction in Concrete
• Effective Date: 01-Dec-2023

Overview

ASTM C1293/C1293M-23a: Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction, published by ASTM International, provides a comprehensive procedure to evaluate the susceptibility of concrete aggregates to alkali-silica reaction (ASR). ASR is a deleterious chemical reaction between alkalis in cement and certain reactive silica-bearing aggregates, which can cause harmful expansion and cracking in concrete structures.

The method involves the measurement of length change in concrete prisms made with the aggregate under investigation. The primary goal is to assess the potential for expansion due to ASR and guide decisions on the suitability of aggregates or mitigation when using supplementary cementitious materials like pozzolans or slag.

Key Topics

• Alkali-Silica Reaction (ASR): A chemical process between alkali hydroxides in cement and reactive silica in aggregates that can cause expansion and cracking in concrete.
• Aggregate Evaluation: The standard establishes a method for testing both coarse and fine aggregates, individually or in combination with pozzolans or slag, to determine their susceptibility to ASR.
• Mitigation Assessment: Results from the test method are used to determine the minimum quantity of pozzolan or slag needed to prevent detrimental expansion in concrete.
• Sampling and Variability: The procedure emphasizes careful sample selection to account for lithological variability in aggregate sources, referencing supporting guides such as ASTM C295/C295M.
• Testing Conditions: Concrete prisms are cured under controlled humid and thermal conditions that accelerate any potential ASR effects, with monitoring at scheduled intervals over extended periods.

Applications

The ASTM C1293/C1293M-23a standard test method is widely applied in:

• Concrete Mixture Qualification: Determining if aggregates meet requirements for use in concrete where durability and long service life are essential, such as infrastructure and structural projects.
• New Aggregate Source Approval: Assessing new quarries or sources of aggregates for potential expansion caused by ASR, prior to their acceptance in concrete production.
• Evaluation of Mitigation Strategies: Verifying the effectiveness of supplementary cementing materials such as pozzolans or slag in controlling expansion from ASR in concrete mixtures.
• Material Specifications and Quality Control: Ensuring compliance with project specifications that require the use of non-expansive aggregates or specific mitigation approaches for ASR.
• Research and Development: Supporting the development of new materials and concrete mix designs through controlled laboratory assessments of aggregate reactivity.

Using this standard helps prevent costly failures related to ASR such as cracking, loss of integrity, and shortened lifespan of concrete structures.

Related Standards

Several ASTM and international standards support or are referenced by ASTM C1293/C1293M-23a, including:

• ASTM C295/C295M: Guide for Petrographic Examination of Aggregates for Concrete
• ASTM C1260: Test Method for Potential Alkali Reactivity of Aggregates (Mortar-Bar Method)
• ASTM C1778: Guide for Reducing the Risk of Deleterious Alkali-Aggregate Reaction in Concrete
• ASTM C33/C33M: Specification for Concrete Aggregates
• ASTM C618: Specification for Coal Ash and Raw or Calcined Natural Pozzolan for Use in Concrete
• ASTM C989/C989M: Specification for Slag Cement for Use in Concrete and Mortars
• CSA A23.2-14A: Potential Expansivity of Aggregates (Procedure for Length Change due to Alkali-Aggregate Reaction in Concrete Prisms)
• ASTM C150/C150M and C595/C595M: Specifications for Portland and Blended Hydraulic Cements

By following ASTM C1293/C1293M-23a and related standards, organizations can improve the long-term quality and reliability of concrete infrastructure by identifying and mitigating risks associated with alkali-silica reaction. This is essential for ensuring good construction practices and durability in concrete applications.

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: C1293/C1293M − 23a
Standard Test Method for
Determination of Length Change of Concrete Due to Alkali-
Silica Reaction
This standard is issued under the fixed designation C1293/C1293M; 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
2.1 ASTM Standards:
1.1 This test method covers the determination of the sus-
C29/C29M Test Method for Bulk Density (“Unit Weight”)
ceptibility of an aggregate or combination of an aggregate with
and Voids in Aggregate
pozzolan or slag for participation in expansive alkali-silica
C33/C33M Specification for Concrete Aggregates
reaction by measurement of length change of concrete prisms.
C114 Test Methods for Chemical Analysis of Hydraulic
1.2 The values stated in either SI units or inch-pound units
Cement
are to be regarded separately as the standard. The values stated
C125 Terminology Relating to Concrete and Concrete Ag-
in each system are not necessarily exact equivalents; therefore,
gregates
to ensure conformance with the standard, each system shall be
C138/C138M Test Method for Density (Unit Weight), Yield,
used independently of the other, and values from the two
and Air Content (Gravimetric) of Concrete
systems shall not be combined.
C143/C143M Test Method for Slump of Hydraulic-Cement
NOTE 1—Sieve size is identified by its standard designation in Speci-
Concrete
fication E11. The alternative designation given in parentheses is for
C150/C150M Specification for Portland Cement
information only and does not represent a different standard sieve size.
C157/C157M Test Method for Length Change of Hardened
1.3 The text of this standard refers to notes and footnotes Hydraulic-Cement Mortar and Concrete
that provide explanatory material. These notes and footnotes C192/C192M Practice for Making and Curing Concrete Test
(excluding those in tables and figures) shall not be considered Specimens in the Laboratory
as requirements of the standard. C294 Descriptive Nomenclature for Constituents of Con-
crete Aggregates
1.4 This standard does not purport to address all of the
C295/C295M Guide for Petrographic Examination of Ag-
safety concerns, if any, associated with its use. It is the
gregates for Concrete
responsibility of the user of this standard to establish appro-
C490/C490M Practice for Use of Apparatus for the Deter-
priate safety, health, and environmental practices and deter-
mination of Length Change of Hardened Cement Paste,
mine the applicability of regulatory limitations prior to use.
Mortar, and Concrete
(Warning—Fresh hydraulic cementitious mixtures are caustic
C494/C494M Specification for Chemical Admixtures for
and may cause chemical burns to skin and tissue upon
Concrete
prolonged exposure. )
C595/C595M Specification for Blended Hydraulic Cements
1.5 This international standard was developed in accor-
C618 Specification for Coal Ash and Raw or Calcined
dance with internationally recognized principles on standard-
Natural Pozzolan for Use in Concrete
ization established in the Decision on Principles for the
C702/C702M Practice for Reducing Samples of Aggregate
Development of International Standards, Guides and Recom-
to Testing Size
mendations issued by the World Trade Organization Technical
C856/C856M Practice for Petrographic Examination of
Barriers to Trade (TBT) Committee.
Hardened Concrete
C989/C989M Specification for Slag Cement for Use in
Concrete and Mortars
C1240 Specification for Silica Fume Used in Cementitious
This test method is under the jurisdiction of Committee C09 on Concrete and
Concrete Aggregates and is the direct responsibility of Subcommittee C09.50 on
Mixtures
Aggregate Reactions in Concrete.
Current edition approved Dec. 1, 2023. Published January 2024. Originally
approved in 1995. Last previous edition approved in 2023 as C1293 – 23. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/C1293_C1293M-23A. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Section on Safety Precautions, “Manual of Aggregate and Concrete Testing,” Standards volume information, refer to the standard’s Document Summary page on
Annual Book of ASTM Standards, Vol 04.02. 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
C1293/C1293M − 23a
C1260 Test Method for Potential Alkali Reactivity of Ag- formed under prescribed laboratory curing conditions that will
gregates (Mortar-Bar Method) probably differ from field conditions. Thus, actual field perfor-
C1778 Guide for Reducing the Risk of Deleterious Alkali-
mance will not be duplicated due to differences in concrete
Aggregate Reaction in Concrete
alkali content, wetting and drying, temperature, other factors,
D75/D75M Practice for Sampling Aggregates
or combinations of these (5).
E11 Specification for Woven Wire Test Sieve Cloth and Test
4.6 Results of tests conducted on an aggregate as described
Sieves
4 herein should form a part of the basis for a decision as to
2.2 CSA Standards:
whether precautions should be taken against excessive expan-
CSA A23.2-14A Potential Expansivity of Aggregates (Pro-
sion due to alkali-silica reaction. For interpretation of test
cedure for Length Change due to Alkali-Aggregate Reac-
results, refer to Guide C1778.
tion in Concrete Prisms at 38 °C)
CSA A23.2-27A Standard Practice to Identify Degree of
4.7 If the expansions in this test method are greater than the
Alkali-Reactivity of Aggregates and to Identify Measures
limit shown in Guide C1778, the aggregate or combination of
to Avoid Deleterious Expansion in Concrete
aggregate with the tested amount of pozzolan or slag is
CSA A23.2-28A Standard Practice for Laboratory Testing to
potentially alkali-reactive. Supplemental information should be
Demonstrate the Effectiveness of Supplementary Cement-
developed to confirm that the expansion is actually due to
ing Materials and Lithium-Based Admixtures to Prevent
alkali-silica reaction. Petrographic examination of the concrete
Alkali-Silica Reaction in Concrete
prisms should be conducted after the test using Practice
C856/C856M to confirm that known reactive constituents are
3. Terminology
present and to identify the products of alkali-silica reactivity.
3.1 Terminology used in this standard is as given in Termi-
Confirmation of alkali-silica reaction is also derived from the
nology C125 or Descriptive Nomenclature C294.
results of the test methods this procedure supplements (see
Guide C1778).
4. Significance and Use
4.1 Alkali-silica reaction is a chemical interaction between 4.8 This test method does not address the general suitability
some siliceous constituents of concrete aggregates and hy- of pozzolans or slag for use in concrete. These materials should
droxyl ions (1). The concentration of hydroxyl ion within the
comply with Specification C618, Specification C989/C989M,
concrete is predominantly controlled by the concentration of
or Specification C1240.
sodium and potassium (2).
5. Apparatus
4.2 This test method is intended to evaluate the potential of
an aggregate or combination of an aggregate with pozzolan or
5.1 The molds, the associated items for molding test
slag to expand deleteriously due to any form of alkali-silica
specimens, and the length comparator for measuring length
reactivity (3, 4).
change shall conform to the applicable requirements of Test
4.3 If testing an aggregate with pozzolan or slag, the results
Method C157/C157M and Practice C490/C490M, and the
are used to establish minimum amounts of the specific pozzo-
molds shall have nominal 75 mm [3 in.] square cross sections.
lan or slag needed to prevent deleterious expansion. Pozzolan
5.2 The storage container options required to maintain the
or slag from a specific source can be tested individually or in
prisms at a high relative humidity are described in 5.2.1.
combination with pozzolan or slag from other sources.
5.2.1 Recommended Container—The recommended con-
4.4 When selecting a sample or deciding on the number of
tainers are 19 L to 22 L [5 gal to 6 gal] polyethylene pails with
samples for test, it is important to recognize the variability in
airtight lids and approximate dimensions of 250 mm to
lithology of material from a given source, whether a deposit of
3 3
270 mm [9 ⁄4 in. to 10 ⁄4 in.] diameter at bottom, 290 mm to
sand, gravel, or a rock formation of any origin. For specific
1 1
310 mm [11 ⁄4 in. to 12 ⁄4 in.] at top, by 355 mm to 480 mm
advice, see Guide C295/C295M.
[14 in. to 19 in.] high. Prevent significant loss of enclosed
4.5 This test method is intended for evaluating the behavior
moisture due to evaporation with airtight lid seal. Place a
of aggregates in concrete with an alkali (alkali metal oxide)
perforated rack in the bottom of the storage container so that
3 3
content of 5.25 kg/m [8.85 lb/yd ] or in concrete containing
1 5
the prisms are 30 mm to 40 mm [1 ⁄8 in. to 1 ⁄8 in.] above the
pozzolan or slag with an alkali content proportionally reduced
bottom. Fill the container with water to a depth of 20 mm 6 5
3 3
from 5.25 kg/m [8.85 lb/yd ] Na O equivalent by the amount
3 1
mm [ ⁄4 in. 6 ⁄4 in.] above the bottom. A significant moisture
of pozzolan or slag replacing portland cement or portland-
loss is defined as a loss greater than 3 % of the original amount
limestone cement. This test method assesses the potential for
of water placed at the bottom of the pail. Place a wick of
deleterious expansion of concrete caused by alkali-silica
absorbent material around the inside wall of the container from
reaction, of either coarse or fine aggregates, from tests per-
the top so that the bottom of the wick extends into the water
(see Note 2).
Available from Canadian Standards Association (CSA), 5060 Spectrum Way,
5.2.2 Alternative Containers—Alternative storage contain-
Mississauga, ON L4W 5N6, Canada, http://www.csa.ca.
5 ers may be used. Confirm the efficiency of the alternative
The boldface numbers in parentheses refer to a list of references at the end of
this standard. storage container with an alkali-reactive aggregate of known
C1293/C1293M − 23a
expansion characteristics. The expansion efficiency is con- 6.2 Water:
firmed when expansions at one year obtained using the 6.2.1 Use potable tap water for mixing and storage.
alternative container are within 10 % of those obtained using
7. Materials
the recommended container. Alternative storage containers
must contain the required depth of water. When reporting
7.1 Cement—Use a cement meeting the requirements for a
results, note the use of an alternative container, if one is used,
Type I portland cement as specified in Specification C150/
together with documentation proving compliance with the
C150M or a Type IL portland-limestone cement as specified in
above. Specification C595/C595M. The cement must have a total
alkali content of 0.9 6 0.1 % Na O equivalent (Na O equiva-
2 2
NOTE 2—Polypropylene geotextile fabric or blotting paper are suitable
lent is calculated as percent Na O + 0.658 × percent K O).
materials for use as the wick. 2 2
Determine the total alkali content of the cement either by
5.3 The storage environment necessary to maintain the 38.0
analysis or by obtaining a mill run certificate from the cement
°C [100.5 °F] reaction accelerating storage temperature con-
manufacturer. Add NaOH to the concrete mixing water so as to
sistently and homogeneously is described in 5.3.1.
increase the alkali content of the mixture, expressed as Na O
5.3.1 Recommended Environment—The recommended stor-
equivalent, to 1.25 % by mass of cement (see Note 4).
age environment is a sealed space insulated so as to minimize
heat loss. Provide a fan for air circulation so the maximum NOTE 4—The value of 1.25 % Na O equivalent by mass of cement has
been chosen to accelerate the process of expansion rather than to
variation in temperature measured within 250 mm [10 in.] of
3 3
reproduce field conditions. At the 420 kg/m [710 lb ⁄yd ] cement content,
the top and bottom of the space does not exceed 2.0 °C
3 3
this corresponds to an alkali level of 5.25 kg/m [8.85 lb ⁄yd ].
[3.5 °F]. Provide an insulated entry door with adequate seals so
NOTE 5—The equivalent alkali content of the cement can be requested
as to minimize heat loss. Racks for storing containers within
from the supplier if it is not reported on the mill test report or can be
determined independently on a sample of the cement according to Test
the space are not to be closer than 30 mm [1 ⁄4 in.] to the sides
Methods C114.
of the enclosure and are to be perforated so as to provide air
flow. Provide an automatically controlled heat source to 7.2 Aggregates:
maintain the temperature at 38.0 °C 6 2.0 °C [100.5 °F 6
7.2.1 To evaluate the reactivity of a coarse aggregate, use a
3.5 °F] (see Note 3). Record the ambient temperature and its nonreactive fine aggregate. A nonreactive fine aggregate is
variation within the space to ensure compliance. defined as an aggregate that develops an expansion in the
accelerated mortar bar, (see Test Method C1260) of less than
NOTE 3—It has been found to be good practice to monitor the efficiency
0.10 % at 14 days (see Guide C1778 for interpretation of
of the storage environment by placing thermocouples inside dummy
expansion data). Use a fine aggregate meeting Specification
concrete specimens inside a dummy container within the storage area.
C33/C33M with a fineness modulus of 2.7 6 0.2.
5.3.2 Alternative Storage Environment—Use of an alterna-
7.2.2 To evaluate the reactivity of a fine aggregate, use a
tive storage environment is permitted. Confirm the efficiency
nonreactive coarse aggregate. Prepare the nonreactive coarse
of the alternative storage container with an alkali-reactive
aggregate according to 7.2.3. A nonreactive coarse aggregate
aggregate of known expansion characteristics. The expansion
is defined as an aggregate that develops an expansion in the
efficiency is confirmed when expansions at one year obtained
accelerated mortar bar (see Test Method C1260) of less than
using the alternative storage environment are within 10 % of
0.10 % at 14 days (see Guide C1778 for interpretation of
those obtained using the recommended environment. When
expansion data). Use a coarse aggregate meeting Specification
reporting the results, note the use of an alternative storage
C33/C33M. Test the fine aggregate using the grading as
environment, if one is utilized, together with documentation
delivered to the laboratory.
proving compliance with the above.
7.2.3 Sieve the coarse aggregate and recombine in accor-
6. Reagents
dance with the requirements in Table 1. Select the Table 1
grading based on the as-received grading of the sample. Coarse
6.1 Sodium Hydroxide (NaOH)—USP or technical grade
aggregate fractions larger than 19.0 mm ( ⁄4 in.) sieve are not to
may be used. (Warning—Before using NaOH, review: (1) the
be tested as such. If petrographic examination using Guide
safety precautions for using NaOH; (2) first aid for burns; and
C295/C295M reveals that the material making up the size
(3) the emergency response to spills as described in the
fraction larger than the 19.0 mm ( ⁄4 in.) sieve is of such a
manufacturers Material Safety Data Sheet or other reliable
composition and lithology that no difference should be ex-
safety literature. NaOH can cause severe burns and injury to
pected compared with the smaller size material, then no further
unprotected skin and eyes. Always use suitable personal
attention need be paid to the larger sizes. If petrographic
protective equipment including: full-face shields, rubber
aprons, and gloves impervious to NaOH. (Check periodically
TABLE 1 Grading Requirement
for pinholes.))
Sieve Size Mass Fraction
Passing Retained Coarse Intermediate
The sole source of supply of non-reactive aggregates and alkali-silica reactive
1 1
19.0 mm 12.5 mm ( ⁄2 in.) ⁄3 . . .
aggregates of known expansion characteristics (6) known to the committee at this 3
( ⁄4 in.)
time is
...

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: C1293/C1293M − 23 C1293/C1293M − 23a
Standard Test Method for
Determination of Length Change of Concrete Due to Alkali-
Silica Reaction
This standard is issued under the fixed designation C1293/C1293M; 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 the determination of the susceptibility of an aggregate or combination of an aggregate with pozzolan
or slag for participation in expansive alkali-silica reaction by measurement of length change of concrete prisms.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as the 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.
NOTE 1—Sieve size is identified by its standard designation in Specification E11. The alternative designation given in parentheses is for information only
and does not represent a different standard sieve size.
1.3 The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding
those in tables and figures) shall not be considered as requirements of the standard.
1.4 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. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns
to skin and tissue upon prolonged exposure. )
1.5 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:
C29/C29M Test Method for Bulk Density (“Unit Weight”) and Voids in Aggregate
C33/C33M Specification for Concrete Aggregates
C114 Test Methods for Chemical Analysis of Hydraulic Cement
C125 Terminology Relating to Concrete and Concrete Aggregates
C138/C138M Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
C143/C143M Test Method for Slump of Hydraulic-Cement Concrete
This test method is under the jurisdiction of Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.50 on Aggregate
Reactions in Concrete.
Current edition approved Nov. 1, 2023Dec. 1, 2023. Published November 2023January 2024. Originally approved in 1995. Last previous edition approved in 20202023
as C1293 – 20a.C1293 – 23. DOI: 10.1520/C1293_C1293M-23.10.1520/C1293_C1293M-23A.
Section on Safety Precautions, “Manual of Aggregate and Concrete Testing,” Annual Book of ASTM Standards, Vol 04.02.
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
C1293/C1293M − 23a
C150/C150M Specification for Portland Cement
C157/C157M Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete
C192/C192M Practice for Making and Curing Concrete Test Specimens in the Laboratory
C294 Descriptive Nomenclature for Constituents of Concrete Aggregates
C295/C295M Guide for Petrographic Examination of Aggregates for Concrete
C490/C490M Practice for Use of Apparatus for the Determination of Length Change of Hardened Cement Paste, Mortar, and
Concrete
C494/C494M Specification for Chemical Admixtures for Concrete
C595/C595M Specification for Blended Hydraulic Cements
C618 Specification for Coal Ash and Raw or Calcined Natural Pozzolan for Use in Concrete
C702/C702M Practice for Reducing Samples of Aggregate to Testing Size
C856/C856M Practice for Petrographic Examination of Hardened Concrete
C989/C989M Specification for Slag Cement for Use in Concrete and Mortars
C1240 Specification for Silica Fume Used in Cementitious Mixtures
C1260 Test Method for Potential Alkali Reactivity of Aggregates (Mortar-Bar Method)
C1778 Guide for Reducing the Risk of Deleterious Alkali-Aggregate Reaction in Concrete
D75/D75M Practice for Sampling Aggregates
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
2.2 CSA Standards:
CSA A23.2-14A Potential Expansivity of Aggregates (Procedure for Length Change due to Alkali-Aggregate Reaction in
Concrete Prisms at 38 °C)
CSA A23.2-27A Standard Practice to Identify Degree of Alkali-Reactivity of Aggregates and to Identify Measures to Avoid
Deleterious Expansion in Concrete
CSA A23.2-28A Standard Practice for Laboratory Testing to Demonstrate the Effectiveness of Supplementary Cementing
Materials and Lithium-Based Admixtures to Prevent Alkali-Silica Reaction in Concrete
3. Terminology
3.1 Terminology used in this standard is as given in Terminology C125 or Descriptive Nomenclature C294.
4. Significance and Use
4.1 Alkali-silica reaction is a chemical interaction between some siliceous constituents of concrete aggregates and hydroxyl ions
(1). The concentration of hydroxyl ion within the concrete is predominantly controlled by the concentration of sodium and
potassium (2).
4.2 This test method is intended to evaluate the potential of an aggregate or combination of an aggregate with pozzolan or slag
to expand deleteriously due to any form of alkali-silica reactivity (3, 4).
4.3 If testing an aggregate with pozzolan or slag, the results are used to establish minimum amounts of the specific pozzolan or
slag needed to prevent deleterious expansion. Pozzolan or slag from a specific source can be tested individually or in combination
with pozzolan or slag from other sources.
4.4 When selecting a sample or deciding on the number of samples for test, it is important to recognize the variability in lithology
of material from a given source, whether a deposit of sand, gravel, or a rock formation of any origin. For specific advice, see Guide
C295/C295M.
4.5 This test method is intended for evaluating the behavior of aggregates portland cement in concrete with an alkali (alkali metal
3 3
oxide) content of 5.25 kg/m [8.85 lblb/yd⁄yd ] or in concrete containing pozzolan or slag with an alkali content proportionally
3 3
reduced from 5.25 kg/m [8.85 lb/yd ] Na O equivalent by the amount of pozzolan or slag replacing portland cement or
portland-limestone cement. This test method assesses the potential for deleterious expansion of concrete caused by alkali-silica
reaction, of either coarse or fine aggregates, from tests performed under prescribed laboratory curing conditions that will probably
differ from field conditions. Thus, actual field performance will not be duplicated due to differences in concrete alkali content,
wetting and drying, temperature, other factors, or combinations of these (5).
Available from Canadian Standards Association (CSA), 5060 Spectrum Way, Mississauga, ON L4W 5N6, Canada, http://www.csa.ca.
The boldface numbers in parentheses refer to a list of references at the end of this standard.
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4.6 Results of tests conducted on an aggregate as described herein should form a part of the basis for a decision as to whether
precautions should be taken against excessive expansion due to alkali-silica reaction. For interpretation of test results, refer to
Guide C1778.
4.7 If the expansions in this test method are greater than the limit shown in Guide C1778, the aggregate or combination of
aggregate with the tested amount of pozzolan or slag is potentially alkali-reactive. Supplemental information should be developed
to confirm that the expansion is actually due to alkali-silica reaction. Petrographic examination of the concrete prisms should be
conducted after the test using Practice C856/C856M to confirm that known reactive constituents are present and to identify the
products of alkali-silica reactivity. Confirmation of alkali-silica reaction is also derived from the results of the test methods this
procedure supplements (see Guide C1778).
4.8 This test method does not address the general suitability of pozzolans or slag for use in concrete. These materials should
comply with Specification C618, Specification C989/C989M, or Specification C1240.
5. Apparatus
5.1 The molds, the associated items for molding test specimens, and the length comparator for measuring length change shall
conform to the applicable requirements of Test Method C157/C157M and Practice C490/C490M, and the molds shall have nominal
75 mm [3 in.] square cross sections.
5.2 The storage container options required to maintain the prisms at a high relative humidity are described in 5.2.1.
5.2.1 Recommended Container—The recommended containers are 19 L to 22 L [5 gal to 6 gal] polyethylene pails with airtight lids
3 3 1
and approximate dimensions of 250 mm to 270 mm [9 ⁄4 in. to 10 ⁄4 in.] diameter at bottom, 290 mm to 310 mm [11 ⁄4 in. to
12 ⁄4 in.] at top, by 355 mm to 480 mm [14 in. to 19 in.] high. Prevent significant loss of enclosed moisture due to evaporation with
airtight lid seal. Place a perforated rack in the bottom of the storage container so that the prisms are 30 mm to 40 mm [1 ⁄8 in. to
5 3 1
1 ⁄8 in.] above the bottom. Fill the container with water to a depth of 20 mm 6 5 mm [ ⁄4 in. 6 ⁄4 in.] above the bottom. A
significant moisture loss is defined as a loss greater than 3 % of the original amount of water placed at the bottom of the pail. Place
a wick of absorbent material around the inside wall of the container from the top so that the bottom of the wick extends into the
water (see Note 2).
5.2.2 Alternative Containers—Alternative storage containers may be used. Confirm the efficiency of the alternative storage
container with an alkali-reactive aggregate of known expansion characteristics. The expansion efficiency is confirmed when
expansions at one year obtained using the alternative container are within 10 % of those obtained using the recommended
container. Alternative storage containers must contain the required depth of water. When reporting results, note the use of an
alternative container, if one is used, together with documentation proving compliance with the above.
NOTE 2—Polypropylene geotextile fabric or blotting paper are suitable materials for use as the wick.
5.3 The storage environment necessary to maintain the 38.0 °C [100.5 °F] reaction accelerating storage temperature consistently
and homogeneously is described in 5.3.1.
5.3.1 Recommended Environment—The recommended storage environment is a sealed space insulated so as to minimize heat loss.
Provide a fan for air circulation so the maximum variation in temperature measured within 250 mm [10 in.] of the top and bottom
of the space does not exceed 2.0 °C [3.5 °F]. Provide an insulated entry door with adequate seals so as to minimize heat loss. Racks
for storing containers within the space are not to be closer than 30 mm [1 ⁄4 in.] to the sides of the enclosure and are to be perforated
so as to provide air flow. Provide an automatically controlled heat source to maintain the temperature at 38.0 °C 6 2.0 °C [100.5 °F
6 3.5 °F] (see Note 3). Record the ambient temperature and its variation within the space to ensure compliance.
NOTE 3—It has been found to be good practice to monitor the efficiency of the storage environment by placing thermocouples inside dummy concrete
specimens inside a dummy container within the storage area.
The sole source of supply of non-reactive aggregates and alkali-silica reactive aggregates of known expansion characteristics (6) known to the committee at this time
is The Petrographer, Engineering Materials Office, Ministry of Transportation, 1201 Wilson Ave., Downsview, Ontario, Canada, M3M1J8. 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.
C1293/C1293M − 23a
5.3.2 Alternative Storage Environment—Use of an alternative storage environment is permitted. Confirm the efficiency of the
alternative storage container with an alkali-reactive aggregate of known expansion characteristics. The expansion efficiency is
confirmed when expansions at one year obtained using the alternative storage environment are within 10 % of those obtained using
the recommended environment. When reporting the results, note the use of an alternative storage environment, if one is utilized,
together with documentation proving compliance with the above.
6. Reagents
6.1 Sodium Hydroxide (NaOH)—USP or technical grade may be used. (Warning—Before using NaOH, review: (1) the safety
precautions for using NaOH; (2) first aid for burns; and (3) the emergency response to spills as described in the manufacturers
Material Safety Data Sheet or other reliable safety literature. NaOH can cause severe burns and injury to unprotected skin and eyes.
Always use suitable personal protective equipment including: full-face shields, rubber aprons, and gloves impervious to NaOH.
(Check periodically for pinholes.))
6.2 Water:
6.2.1 Use potable tap water for mixing and storage.
7. Materials
7.1 Cement—Use a cement meeting the requirements for a Type I Portlandportland cement as specified in Specification
C150/C150M or a Type IL portland-limestone cement as specified in Specification C595/C595M. The cement must have a total
alkali content of 0.9 6 0.1 % Na O equivalent (Na O equivalent is calculated as percent Na O + 0.658 × percent K O). Determine
2 2 2 2
the total alkali content of the cement either by analysis or by obtaining a mill run certificate from the cement manufacturer. Add
NaOH to the concrete mixing water so as to increase the alkali content of the mixture, expressed as Na O equivalent, to 1.25 %
by mass of cement (see Note 4).
NOTE 4—The value of 1.25 % Na O equivalent by mass of cement has been chosen to accelerate the process of expansion rather than to reproduce field
3 3 3 3
conditions. At the 420 kg/m [710 lb ⁄yd ] cement content, this corresponds to an alkali level of 5.25 kg/m [8.85 lb ⁄yd ].
NOTE 5—The equivalent alkali content of the cement can be requested from the supplier if it is not reported on the mill test report or can be determined
independently on a sample of the cement according to Test Methods C114.
7.2 Aggregates:
7.2.1 To evaluate the reactivity of a coarse aggregate, use a nonreactive fine aggregate. A nonreactive fine aggregate is defined as
an aggregate that develops an expansion in the accelerated mortar bar, (see Test Method C1260) of less than 0.10 % at 14 days
(see Guide C1778 for interpretation of expansion data). Use a fine aggregate meeting Specification C33/C33M with a fineness
modulus of 2.7 6 0.2.
7.2.2 To evaluate the reactivity of a fine aggregate, use a nonreactive coarse aggregate. Prepare the nonreactive coarse aggregate
according to 7.2.3. A nonreactive coarse aggregate is defined as an aggregate that develops an expansion in the accelerated mortar
bar (see Test Method C1260) of less than 0.10 % at 14 days (see Guide C1778 for interpretation of expansion data). Use a coarse
aggregate meeting Specification C33/C33M. Test the fine aggregate using the grading as delivered to the laboratory.
7.2.3 Sieve the coarse aggregate and recombine in accordance with the requirements in Table 1. Select the Table 1 grading based
on the as-received grading of the sample. Coarse aggregate fractions larger than 19.0 mm ( ⁄4 in.) sieve are not to be tested as such.
If petrographic examination using Guide C295/C295M reveals that t
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