ASTM C1928/C1928M-23

Standard Test Method for Compressive Strength of Alkali Activated Cementitious Material Mortars (Using 2-in. [50 mm] Cube Specimens)

SIGNIFICANCE AND USE
5.1 This test method provides a means of determining the compressive strength of alkali-activated cementitious material mortars and results may be used to determine compliance with specifications.
SCOPE
1.1 This test method covers determination of the compressive strength of alkali activated cementitious material mortars, using 2-in. [50 mm] cube specimens.  
1.2 This test method references 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 test method.  
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. If required results obtained from another standard are not reported in the same system of units as used by this standard, it is permitted to convert those results using the conversion factors found in the SI Quick Reference Guide.  
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: 14-Feb-2023
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: C01 - Cement
• Drafting Committee: C01.14 - Non-hydraulic Cements

Relations

• Refers: ASTM C219-24 - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Apr-2024
• Refers: ASTM C109/C109M-23 - Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 50 mm [2 in.] Cube Specimens)
• Effective Date: 15-Dec-2023
• Refers: ASTM C219-20a - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Aug-2020
• Refers: ASTM C305-20 - Standard Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency
• Effective Date: 15-Jul-2020
• Refers: ASTM C219-20 - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Apr-2020
• Refers: ASTM C219-19a - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 15-Nov-2019
• Refers: ASTM C219-19 - Standard Terminology Relating to Hydraulic Cement
• Effective Date: 01-Jun-2019
• Refers: ASTM C1005-18 - Standard Specification for Reference Masses and Devices for Determining Mass and Volume for Use in the Physical Testing of Hydraulic Cements
• Effective Date: 01-May-2018
• Refers: ASTM C1005-17 - Standard Specification for Reference Masses and Devices for Determining Mass and Volume for Use in the Physical Testing of Hydraulic Cements
• Effective Date: 15-Mar-2017
• Refers: ASTM C1433-16b - Standard Specification for Precast Reinforced Concrete Monolithic Box Sections for Culverts, Storm Drains, and Sewers
• Effective Date: 01-Nov-2016
• Refers: ASTM C1433-16a - Standard Specification for Precast Reinforced Concrete Monolithic Box Sections for Culverts, Storm Drains, and Sewers
• Effective Date: 01-Feb-2016
• Refers: ASTM C1433-16 - Standard Specification for Precast Reinforced Concrete Monolithic Box Sections for Culverts, Storm Drains, and Sewers
• Effective Date: 15-Jan-2016
• Refers: ASTM C1433-15 - Standard Specification for Precast Reinforced Concrete Monolithic Box Sections for Culverts, Storm Drains, and Sewers
• Effective Date: 01-Apr-2015
• Refers: ASTM C230/C230M-14 - Standard Specification for Flow Table for Use in Tests of Hydraulic Cement
• Effective Date: 01-Oct-2014
• Refers: ASTM C219-14 - Standard Terminology Relating to Hydraulic Cement
• Effective Date: 01-Jul-2014

Overview

ASTM C1928/C1928M-23: Standard Test Method for Compressive Strength of Alkali Activated Cementitious Material Mortars (Using 2-in. [50 mm] Cube Specimens) establishes procedures for determining the compressive strength of mortars made with alkali activated cementitious materials (AACM). These materials, which may also be referred to as alkali-activated binders or geopolymer cements, are increasingly utilized in sustainable construction. The standard outlines the preparation, curing, and testing procedures using 2-in. (50 mm) cube specimens to ensure quality and compliance with relevant specifications.

Key Topics

• Compressive Strength Measurement:
  The standard provides a unified method for assessing the compressive strength of AACM mortars, a critical parameter for structural performance.

• Specimen Preparation:

  • Use of standardized 2-in. [50 mm] cube molds
  • Following manufacturer-recommended mixing protocols
  • Proper handling and consolidation of mortar

• Curing Conditions:

  • Options for room temperature or elevated temperature curing
  • Procedures to prevent moisture loss and ensure accurate results

• Reporting Requirements:
  Reports generated under this standard include details on:

  • Composition of precursor materials and alkali activators
  • Dosage rates and mixing protocols
  • Curing methods
  • Measured compressive strengths, including averages and specimen ages

• Unit Consistency:
  The standard emphasizes the importance of using either SI or inch-pound units exclusively, avoiding conversion between systems to maintain accuracy.

• Safety Considerations:
  Users are cautioned about the caustic nature of fresh AACM mixtures and are responsible for implementing safety, health, and environmental practices.

Applications

ASTM C1928/C1928M-23 is widely applicable in research, quality control, and specification compliance for construction projects that utilize alkali activated cementitious materials. Key applications include:

• Material Performance Evaluation:
  Enables manufacturers, researchers, and quality assurance teams to assess the strength development of AACM mortars, supporting product development and improvement.

• Compliance Testing:
  Construction projects and regulatory bodies can use this test method to determine if AACM products meet required performance standards.

• Comparative Analysis:
  Facilitates comparison between traditional Portland cement mortars and alkali activated alternatives in terms of compressive strength, supporting sustainable material selection.

• Specification Development:
  Assists architects, engineers, and specifiers in defining compressive strength requirements for Alkali-Activated Cementitious Material mortar used in sustainable and high-performance construction projects.

Related Standards

Several references and related ASTM standards help ensure consistency and reliability in the testing process:

• ASTM C109/C109M - Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or [50 mm] Cube Specimens)
• ASTM C305 - Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency
• ASTM C778 - Specification for Standard Sand
• ASTM C219 - Terminology Relating to Hydraulic and Other Inorganic Cements
• ASTM C511 - Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic Cements and Concretes
• ASTM C1437 - Test Method for Flow of Hydraulic Cement Mortar
• SI 10 - American National Standard for Metric Practice

Practical Value

Adhering to ASTM C1928/C1928M-23 ensures consistent, accurate, and reproducible compressive strength results for AACM mortars. This fosters confidence in innovative, sustainable cementitious materials as reliable alternatives to traditional products, facilitating greater adoption in construction practices worldwide. The standard supports sustainability goals by providing clear guidance for testing and specifying high-performance, environmentally-friendly binders.

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: C1928/C1928M − 23
Standard Test Method for
Compressive Strength of Alkali Activated Cementitious
Material Mortars (Using 2-in. [50 mm] Cube Specimens)
This standard is issued under the fixed designation C1928/C1928M; 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
1.1 This test method covers determination of the compres- 2.1 ASTM Standards:
sive strength of alkali activated cementitious material mortars, C109/C109M Test Method for Compressive Strength of
using 2-in. [50 mm] cube specimens. Hydraulic Cement Mortars (Using 2-in. or [50 mm] Cube
Specimens)
1.2 This test method references notes and footnotes that
C183/C183M Practice for Sampling and the Amount of
provide explanatory material. These notes and footnotes (ex-
Testing of Hydraulic Cement
cluding those in tables and figures) shall not be considered as
C219 Terminology Relating to Hydraulic and Other Inor-
requirements of the test method.
ganic Cements
1.3 The values stated in either SI units or inch-pound units
C230/C230M Specification for Flow Table for Use in Tests
are to be regarded separately as standard. The values stated in
of Hydraulic Cement
each system may not be exact equivalents; therefore, each
C305 Practice for Mechanical Mixing of Hydraulic Cement
system shall be used independently of the other. Combining
Pastes and Mortars of Plastic Consistency
values from the two systems may result in non-conformance
C511 Specification for Mixing Rooms, Moist Cabinets,
with the standard. If required results obtained from another
Moist Rooms, and Water Storage Tanks Used in the
standard are not reported in the same system of units as used by
Testing of Hydraulic Cements and Concretes
this standard, it is permitted to convert those results using the
C778 Specification for Standard Sand
conversion factors found in the SI Quick Reference Guide.
C1005 Specification for Reference Masses and Devices for
1.4 This standard does not purport to address all of the
Determining Mass and Volume for Use in Physical Testing
safety concerns, if any, associated with its use. It is the
of Hydraulic Cements
responsibility of the user of this standard to establish appro- C1433 Specification for Precast Reinforced Concrete Mono-
priate safety, health, and environmental practices and deter-
lithic Box Sections for Culverts, Storm Drains, and
mine the applicability of regulatory limitations prior to use. Sewers
(Warning—Fresh hydraulic cementitious mixtures are caustic
C1437 Test Method for Flow of Hydraulic Cement Mortar
and may cause chemical burns to skin and tissue upon
2.2 IEEE/ASTM:
prolonged exposure. )
SI 10 American National Standard for Metric Practice
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3. Terminology
ization established in the Decision on Principles for the
3.1 Definitions:
Development of International Standards, Guides and Recom-
3.1.1 For definitions of terms used in this test method, refer
mendations issued by the World Trade Organization Technical
to Terminology C219.
Barriers to Trade (TBT) Committee.
3.2 Definitions of Terms Specific to This Standard:
1 3
This test method is under the jurisdiction of ASTM Committee C01 on Cement For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and is the direct responsibility of Subcommittee C01.14 on Non-hydraulic Cements. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Current edition approved Feb. 15, 2023. Published May 2023. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
C1928_C1928M-23. the ASTM website.
2 4
See the section on Safety, Manual of Cement Testing, Annual Book of ASTM Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),
Standards, Vol 04.01. 445 Hoes Ln., Piscataway, NJ 08854-4141, http://www.ieee.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1928/C1928M − 23
3.2.1 AACM precursor, n—substance consisting of one or 5. Significance and Use
more finely divided solids as the major constituent containing
5.1 This test method provides a means of determining the
both alumina and silica that will react and harden when mixed
compressive strength of alkali-activated cementitious material
with an alkali activator.
mortars and results may be used to determine compliance with
3.2.2 alkali activator, n—source of cations of sodium or specifications.
potassium or both and, in some cases, magnesium or calcium
or a combination thereof, as major constituents that, when
6. Apparatus
incorporated in aqueous or solid form, induces reaction,
6.1 Weights and weighing devices shall meet the require-
setting, and hardening of an AACM.
ments of Specification C1005. The weighing device shall be
3.2.2.1 Discussion—Common examples of alkali activators
evaluated for precision and bias at a total load of 2000 g.
include hydroxides, silicates, aluminates, and sulfates of so-
6.2 Glass Graduates, shall conform to the requirements of
dium or potassium.
Test Method C109/C109M.
3.2.3 alkali-activated cementitious material (AACM),
6.3 Specimen Molds, shall meet the requirements and con-
n—substance consisting of an inorganic precursor or blend of
form to the tolerances stated in Test Method C109/C109M.
such precursors that, when combined with an alkali activator,
and with water as the reaction medium, reacts to produce a
6.4 Mixer, Bowl and Paddle, with planetary and revolving
hardened monolithic material.
motion shall conform to the requirements stated in Practice
3.2.3.1 Discussion—An alkali-activated cementitious mate-
C305.
rial may also be known as an alkali-activated cementitious
6.5 Flow Table and Flow Mold, shall conform to Specifica-
binder. Some AACMs are also known as geopolymer cements.
tion C230/C230M.
3.2.4 binder solids, n—part of an AACM consisting of all
6.6 Tamper and Trowel, conforming to Test Method C109/
solids and dissolved solids.
C109M.
3.2.4.1 Discussion—Calculated by subtraction of the water
content from the overall mass of the AACM. 6.7 Testing Machine, shall meet the requirements and con-
form to the tolerances of Test Method C109/C109M.
3.2.5 major constituent, n—powder, usually
aluminosilicate, which is present in an AACM in a proportion
6.8 Oven, of sufficient size, capable of maintaining a uni-
exceeding 5 % by mass of the total material, and which is not
form temperature of 140 °F 6 5 °F [60 °C 6 2 °C].
the alkali activator.
6.9 Moist Cabinet or Room, conforming to the requirements
3.2.5.1 Discussion—An AACM may contain more than one
of Specification C511.
major constituent.
3.2.6 manufacturer, n—the producer that assembles the
7. Materials
AACM from a range of raw ingredients.
7.1 AACM Precursor.
3.2.7 mixing protocol, n—process for combining the AACM
7.2 Alkali activator.
precursor, alkali activator, aggregate, admixture and water as
defined by the manufacturer.
7.3 Graded Standard Sand:
7.3.1 The sand used for making test specimens shall be
3.2.8 mixing water, n—amount of water added during the
natural silica sand conforming to the requirements for graded
mixing of AACM.
standard sand in Specification C778.
3.2.8.1 Discussion—Mixing water does not include water
which is provided as part of the alkaline activator or as part of
NOTE 1—Segregation of Graded Sand—The graded standard sand
an admixture, if these are added as aqueous solutions.
should be handled in such a manner as to prevent segregation, since
variations in the grading of the sand cause variations in the consistency of
3.2.9 total water content, n—amount of added mixing water
the mortar. In emptying bins or sacks, care should be exercised to prevent
plus water in the liquid activators and as admixtures.
the formation of mounds of sand or craters in the sand, down the slopes
of which the coarser particles will roll. Bins should be of sufficient size to
permit these precautions. Devices for drawing the sand from bins by
4. Summary of Test Method
gravity should not be used.
4.1 The mortar consists of AACM precursor material,
AACM alkali activator, sand, and water. The ratio of binder
8. Temperature and Humidity
solids to sand is 1 to 2.75 proportioned by mass. The mixing
8.1 Temperature—The temperature of the air in the vicinity
protocol shall be applied according to the recommendations of
of the mixing slab, the dry materials, molds, base plates, and
the manufacturer of the AACM. Water content is that sufficient
mixing bowl, shall be
...