ASTM C133-24

Standard Test Methods for Cold Crushing Strength and Modulus of Rupture of Refractories

SIGNIFICANCE AND USE
3.1 The cold strength of a refractory material is an indication of its suitability for use in refractory construction. (It is not a measure of performance at elevated temperatures.)  
3.2 These test methods are for determining the room temperature flexural strength in three-point bending (cold modulus of rupture) or compressive strength (cold crushing strength), or both, for all refractory products.  
3.3 Considerable care must be used to compare the results of different determinations of the cold crushing strength or modulus of rupture. The specimen size and shape, the nature of the specimen faces (that is, as-formed, sawed, or ground), the orientation of those faces during testing, the loading geometry, and the rate of load application may all significantly affect the numerical results obtained. Comparisons of the results between different determinations should not be made if one or more of these parameters differ between the two determinations.  
3.4 The relative ratio of the largest grain size to the smallest specimen dimension may significantly affect the numerical results. For example, smaller cut specimens containing large grains may present different results than the bricks from which they were cut. Under no circumstances should 6 in. by 1 in. by 1 in. (152 mm by 25 mm by 25 mm) specimens be prepared and tested for materials containing grains with a maximum grain dimension exceeding 0.25 in. (6.4 mm).  
3.5 This test method is useful for research and development, engineering application and design, manufacturing process control, and for developing purchasing specifications.
SCOPE
1.1 These test methods cover the determination of the cold crushing strength and the modulus of rupture (MOR) of dried or fired refractory shapes of all types.  
1.2 The test methods appear in the following sections:    
Test Method  
Sections    
Cold Crushing Strength  
4 to 8  
Modulus of Rupture  
9 to 13  
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered 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.  
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: 31-Mar-2024
• ICS: 81.080 - Refractories
• Technical Committee: C08 - Refractories
• Drafting Committee: C08.01 - Strength

Relations

• Replaces: ASTM C133-97(2021) - Standard Test Methods for Cold Crushing Strength and Modulus of Rupture of Refractories
• Effective Date: 01-Apr-2024
• Referred By: ASTM C862-16(2020) - Standard Practice for Preparing Refractory Concrete Specimens by Casting
• Effective Date: 01-Apr-2024
• Referred By: ASTM C1190-18(2022) - Standard Practice for Location of Test Specimens from Magnesia-Carbon and Impregnated Burned Basic Brick
• Effective Date: 01-Apr-2024
• Referred By: ASTM C203-22 - Standard Test Methods for Breaking Load and Flexural Properties of Block-Type Thermal Insulation
• Effective Date: 01-Apr-2024
• Referred By: ASTM C27-98(2022) - Standard Classification of Fireclay and High-Alumina Refractory Brick
• Effective Date: 01-Apr-2024
• Referred By: ASTM C198-09(2019) - Standard Test Method for Cold Bonding Strength of Refractory Mortar
• Effective Date: 01-Apr-2024
• Referred By: ASTM C401-12(2022) - Standard Classification of Alumina and Alumina-Silicate Castable Refractories
• Effective Date: 01-Apr-2024
• Referred By: ASTM C416-97(2022) - Standard Classification of Silica Refractory Brick
• Effective Date: 01-Apr-2024
• Referred By: ASTM F1097-17(2022) - Standard Specification for Mortar, Refractory (High-Temperature, Air-Setting)
• Effective Date: 01-Apr-2024
• Referred By: ASTM F1312-19(2023) - Standard Specification for Brick, Insulating, High Temperature, Fire Clay
• Effective Date: 01-Apr-2024
• Referred By: ASTM C607-88(2016) - Standard Practice for Coking Large Shapes of Carbon-Bearing Materials
• Effective Date: 01-Apr-2024
• Referred By: ASTM C1685-15(2021) - Standard Specification for Pneumatically Applied High-Temperature Fiber Thermal Insulation for Industrial Applications
• Effective Date: 01-Apr-2024
• Referred By: ASTM C1171-16(2022) - Standard Test Method for Quantitatively Measuring the Effect of Thermal Shock and Thermal Cycling on Refractories
• Effective Date: 01-Apr-2024

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: C133 − 24
Standard Test Methods for
Cold Crushing Strength and Modulus of Rupture of
1
Refractories
This standard is issued under the fixed designation C133; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope E4 Practices for Force Calibration and Verification of Test-
ing Machines
1.1 These test methods cover the determination of the cold
crushing strength and the modulus of rupture (MOR) of dried
3. Significance and Use
or fired refractory shapes of all types.
3.1 The cold strength of a refractory material is an indica-
1.2 The test methods appear in the following sections:
tion of its suitability for use in refractory construction. (It is not
Test Method Sections
a measure of performance at elevated temperatures.)
Cold Crushing Strength 4 to 8
3.2 These test methods are for determining the room tem-
Modulus of Rupture 9 to 13
perature flexural strength in three-point bending (cold modulus
1.3 The values stated in inch-pound units are to be regarded
of rupture) or compressive strength (cold crushing strength), or
as standard. The values given in parentheses are mathematical
both, for all refractory products.
conversions to SI units that are provided for information only
3.3 Considerable care must be used to compare the results
and are not considered standard.
of different determinations of the cold crushing strength or
1.4 This standard does not purport to address all of the
modulus of rupture. The specimen size and shape, the nature of
safety concerns, if any, associated with its use. It is the
the specimen faces (that is, as-formed, sawed, or ground), the
responsibility of the user of this standard to establish appro-
orientation of those faces during testing, the loading geometry,
priate safety, health, and environmental practices and deter-
and the rate of load application may all significantly affect the
mine the applicability of regulatory limitations prior to use.
numerical results obtained. Comparisons of the results between
1.5 This international standard was developed in accor-
different determinations should not be made if one or more of
dance with internationally recognized principles on standard-
these parameters differ between the two determinations.
ization established in the Decision on Principles for the
3.4 The relative ratio of the largest grain size to the smallest
Development of International Standards, Guides and Recom-
specimen dimension may significantly affect the numerical
mendations issued by the World Trade Organization Technical
results. For example, smaller cut specimens containing large
Barriers to Trade (TBT) Committee.
grains may present different results than the bricks from which
they were cut. Under no circumstances should 6 in. by 1 in. by
2. Referenced Documents
1 in. (152 mm by 25 mm by 25 mm) specimens be prepared
2
2.1 ASTM Standards:
and tested for materials containing grains with a maximum
C862 Practice for Preparing Refractory Concrete Specimens
grain dimension exceeding 0.25 in. (6.4 mm).
by Casting
3.5 This test method is useful for research and development,
C1054 Practice for Pressing and Drying Refractory Plastic
engineering application and design, manufacturing process
and Ramming Mix Specimens
control, and for developing purchasing specifications.
COLD CRUSHING STRENGTH
1
These test methods are under the jurisdiction of ASTM Committee C08 on
4. Apparatus
Refractories and are the direct responsibility of Subcommittee C08.01 on Strength.
Current edition approved April 1, 2024. Published April 2024. Originally
4.1 Testing Machine—Any form of standard mechanical or
approved in 1937. Last previous edition approved in 2021 as C133 – 97 (2021).
hydraulic compression testing machine conforming to the
DOI: 10.1520/C0133-24.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
requirements of Practices E4 may be used.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on NOTE 1—For low-strength materials (such as insulating bricks or
the ASTM website. castables), a sensitivity of 20 lbf (67 kN) or less is required. The use of a
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------
...

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: C133 − 97 (Reapproved 2021) C133 − 24
Standard Test Methods for
Cold Crushing Strength and Modulus of Rupture of
1
Refractories
This standard is issued under the fixed designation C133; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 These test methods cover the determination of the cold crushing strength and the modulus of rupture (MOR) of dried or fired
refractory shapes of all types.
1.2 The test methods appear in the following sections:
Test Method Sections
Cold Crushing Strength 4 to 9
Cold Crushing Strength 4 to 8
Modulus of Rupture 10 to 15
Modulus of Rupture 9 to 13
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered 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.
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
2.1 ASTM Standards:
C862 Practice for Preparing Refractory Concrete Specimens by Casting
C1054 Practice for Pressing and Drying Refractory Plastic and Ramming Mix Specimens
E4 Practices for Force Calibration and Verification of Testing Machines
1
These test methods are under the jurisdiction of ASTM Committee C08 on Refractories and are the direct responsibility of Subcommittee C08.01 on Strength.
Current edition approved Feb. 1, 2021April 1, 2024. Published February 2021April 2024. Originally approved in 1937. Last previous edition approved in 20152021 as
C133 – 97 (2015).(2021). DOI: 10.1520/C0133-97R21.10.1520/C0133-24.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
C133 − 24
3. Significance and Use
3.1 The cold strength of a refractory material is an indication of its suitability for use in refractory construction. (It is not a measure
of performance at elevated temperatures.)
3.2 These test methods are for determining the room temperature flexural strength in three-point bending (cold modulus of rupture)
or compressive strength (cold crushing strength), or both, for all refractory products.
3.3 Considerable care must be used to compare the results of different determinations of the cold crushing strength or modulus
of rupture. The specimen size and shape, the nature of the specimen faces (that is, as-formed, sawed, or ground), the orientation
of those faces during testing, the loading geometry, and the rate of load application may all significantly affect the numerical results
obtained. Comparisons of the results between different determinations should not be made if one or more of these parameters differ
between the two determinations.
3.4 The relative ratio of the largest grain size to the smallest specimen dimension may significantly affect the numerical results.
For example, smaller cut specimens containing large grains may present different results than the bricks from which they were cut.
Under no circumstances should 6 by 1 by 1-in. (152 by 25 by 25-mm)6 in. by 1 in. by 1 in. (152 mm by 25 mm by 25 mm)
specimens be prepared and tested for materials containing grains with a maximum grain dimension exceeding 0.25 in. (6.4 mm).
3.5 This test method is useful for research and development, engineering application and design, manufacturing process control,
and for developing purchasing specifications.
COLD CRUSHING STRENGTH
...