ASTM C20-00(2022)

Standard Test Methods for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick and Shapes by Boiling Water

SIGNIFICANCE AND USE
3.1 Apparent porosity, water absorption, apparent specific gravity, and bulk density are primary properties of burned refractory brick and shapes. These properties are widely used in the evaluation and comparison of product quality and as part of the criteria for selection and use of refractory products in a variety of industrial applications. These test methods are used for determining any or all of these properties.  
3.2 These test methods are primary standard methods which are suitable for use in quality control, research and development, establishing criteria for and evaluating compliance with specifications, and providing data for design purposes.  
3.3 Fundamental assumptions inherent in these test methods are that the test specimens are not attacked by water, the test specimens conform to the requirements for size, configuration, and original faces, the open pores of the test specimens are fully impregnated with water during the boiling treatment, and the blotting of the saturated test specimens is performed as specified in a consistent and uniform manner to avoid withdrawing water from the pores. Deviation from any of these assumptions adversely affects the test results.  
3.4 In laboratory studies involving castable specimens, a bias was noted between formed 2 by 2 by 2 in. (50 by 50 by 50 mm) and specimens that were quartered from larger 9 by 4.5 by 2.5 (228 by 114 by 64 mm) cast specimens. Additionally, an error in the apparent porosity determination on castables was found whenever the specimens were heated to 1500 °F (816 °C) and then exposed to water as a saturation media (Test Methods C830). The error was attributed to reactivity of cement with water and subsequent re-hydration of cement phases. The higher the cement level of the castable, the greater the error noted. It was concluded that an error in porosity values could occur for refractory materials having a potential to form hydrated species with water.3  
3.5 Certain precautions must be exe...
SCOPE
1.1 These test methods cover the determination of the following properties of burned refractory brick:  
1.1.1 Apparent porosity,  
1.1.2 Water absorption,  
1.1.3 Apparent specific gravity, and  
1.1.4 Bulk density.  
1.2 These test methods are not applicable to refractories attacked by water.  
1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.  
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-Jan-2022
• ICS: 81.080 - Refractories
• Technical Committee: C08 - Refractories
• Drafting Committee: C08.03 - Physical Properties

Relations

• 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 E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011
• Refers: ASTM C830-00(2011) - Standard Test Methods for Apparent Porosity, Liquid Absorption, Apparent Specific Gravity, and Bulk Density of Refractory Shapes by Vacuum Pressure
• Effective Date: 01-Jul-2011
• Refers: ASTM C134-95(2010) - Standard Test Methods for Size, Dimensional Measurements, and Bulk Density of Refractory Brick and Insulating Firebrick
• Effective Date: 01-Apr-2010
• Refers: ASTM E691-08 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Oct-2008
• Refers: ASTM C830-00(2006) - Standard Test Methods for Apparent Porosity, Liquid Absorption, Apparent Specific Gravity, and Bulk Density of Refractory Shapes by Vacuum Pressure
• Effective Date: 01-Jun-2006
• Refers: ASTM C134-95(2005) - Standard Test Methods for Size, Dimensional Measurements, and Bulk Density of Refractory Brick and Insulating Firebrick
• Effective Date: 01-Dec-2005
• Refers: ASTM E691-05 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2005
• Refers: ASTM C830-00 - Standard Test Methods for Apparent Porosity, Liquid Absorption, Apparent Specific Gravity, and Bulk Density of Refractory Shapes by Vacuum Pressure
• Effective Date: 10-Apr-2000
• Refers: ASTM E691-99 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 10-May-1999
• Refers: ASTM C134-95(1999) - Standard Test Methods for Size, Dimensional Measurements, and Bulk Density of Refractory Brick and Insulating Firebrick
• Effective Date: 01-Jan-1999

Overview

ASTM C20-00(2022) is the internationally recognized standard for determining key physical properties of burned refractory bricks and shapes, specifically through boiling water methods. Developed by ASTM Committee C08, this standard outlines reliable test methods to assess apparent porosity, water absorption, apparent specific gravity, and bulk density. Accurate evaluation of these properties is essential for quality control, product comparison, specification compliance, and research and development of refractory materials used in high-temperature industrial applications.

Key Topics

ASTM C20-00(2022) focuses on the following primary aspects:

• Apparent Porosity: Measures the percentage of open pores in burned refractory brick that can be filled with water during boiling treatment.
• Water Absorption: Quantifies the amount of water absorbed by the refractory brick relative to its dry weight.
• Apparent Specific Gravity: Refers to the density of the solid portion of the brick, excluding its open pores, as determined through weighing methods.
• Bulk Density: Represents the mass per unit volume of the test specimen, including both solids and open pores.

The standard provides detailed procedures for preparing specimens, conducting boiling water saturation, and calculating results. It emphasizes that proper specimen selection and handling are critical to avoid errors, especially since the four properties are highly interrelated. Deviations from prescribed methods can adversely impact the reliability of test results.

Applications

The practical value of ASTM C20-00(2022) spans multiple areas within the refractory and ceramics industry:

• Quality Control: Manufacturers and suppliers use these test methods to monitor product consistency and meet client specifications.
• Compliance: The measurements serve as criteria for compliance with national and international requirements for refractory products.
• Product Development: Material scientists and engineers rely on these standardized methods for research and to optimize new high-temperature materials.
• Industrial Selection: End-users in steel, cement, glass, and petrochemical industries utilize the test results for selecting suitable refractory bricks based on specific service conditions.
• Design Validation: Engineers use property data in the design and safety assessment of furnaces, kilns, and thermal process equipment.

It is important to note that these test methods are not suitable for materials attacked by water, or where chemical reactivity with water may influence the measured properties, particularly in some cement-based refractory castables.

Related Standards

For complementary testing and additional guidance, consider the following related ASTM standards:

• ASTM C830: Test Methods for Apparent Porosity, Liquid Absorption, Apparent Specific Gravity, and Bulk Density of Refractory Shapes by Vacuum Pressure.
• ASTM C134: Test Methods for Size, Dimensional Measurements, and Bulk Density of Refractory Brick and Insulating Firebrick.
• ASTM E691: Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method.

These referenced standards provide alternate techniques and broader contexts for quality evaluation within ceramics and refractory industries.

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Keywords: ASTM C20, apparent porosity, water absorption, bulk density, apparent specific gravity, burned refractory brick, refractory shapes, quality control, industrial refractories test methods.

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:C20 −00 (Reapproved 2022)
Standard Test Methods for
Apparent Porosity, Water Absorption, Apparent Specific
Gravity, and Bulk Density of Burned Refractory Brick and
Shapes by Boiling Water
This standard is issued under the fixed designation C20; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
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 C830 Test Methods for Apparent Porosity, Liquid
Absorption, Apparent Specific Gravity, and Bulk Density
1.1 These test methods cover the determination of the
of Refractory Shapes by Vacuum Pressure
following properties of burned refractory brick:
E691 Practice for Conducting an Interlaboratory Study to
1.1.1 Apparent porosity,
Determine the Precision of a Test Method
1.1.2 Water absorption,
1.1.3 Apparent specific gravity, and
3. Significance and Use
1.1.4 Bulk density.
3.1 Apparent porosity, water absorption, apparent specific
1.2 These test methods are not applicable to refractories
gravity, and bulk density are primary properties of burned
attacked by water.
refractory brick and shapes. These properties are widely used
1.3 The values stated in inch-pound units are to be regarded
in the evaluation and comparison of product quality and as part
as the standard. The values given in parentheses are for
of the criteria for selection and use of refractory products in a
information only.
variety of industrial applications. These test methods are used
for determining any or all of these properties.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.2 These test methods are primary standard methods which
responsibility of the user of this standard to establish appro-
are suitable for use in quality control, research and
priate safety, health, and environmental practices and deter-
development, establishing criteria for and evaluating compli-
mine the applicability of regulatory limitations prior to use.
ance with specifications, and providing data for design pur-
1.5 This international standard was developed in accor-
poses.
dance with internationally recognized principles on standard-
3.3 Fundamental assumptions inherent in these test methods
ization established in the Decision on Principles for the
are that the test specimens are not attacked by water, the test
Development of International Standards, Guides and Recom-
specimens conform to the requirements for size, configuration,
mendations issued by the World Trade Organization Technical
and original faces, the open pores of the test specimens are
Barriers to Trade (TBT) Committee.
fully impregnated with water during the boiling treatment, and
the blotting of the saturated test specimens is performed as
2. Referenced Documents
specified in a consistent and uniform manner to avoid with-
2.1 ASTM Standards:
drawing water from the pores. Deviation from any of these
C134 Test Methods for Size, Dimensional Measurements,
assumptions adversely affects the test results.
and Bulk Density of Refractory Brick and Insulating
3.4 In laboratory studies involving castable specimens, a
Firebrick
bias was noted between formed 2 by 2 by 2 in. (50 by 50 by 50
mm)andspecimensthatwerequarteredfromlarger9by4.5by
These test methods are under the jurisdiction of ASTM Committee C08 on
2.5 (228 by 114 by 64 mm) cast specimens. Additionally, an
Refractories and are the direct responsibility of Subcommittee C08.03 on Physical
error in the apparent porosity determination on castables was
Properties.
found whenever the specimens were heated to 1500 °F
Current edition approved Feb. 1, 2022. Published February 2022. Originally
(816 °C) and then exposed to water as a saturation media (Test
approved in 1918. Last previous edition approved in 2015 as C20 – 00 (2015). DOI:
10.1520/C0020-00R22.
Methods C830). The error was attributed to reactivity of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
cement with water and subsequent re-hydration of cement
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
phases. The higher the cement level of the castable, the greater
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. the error noted. It was concluded that an error in porosity
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C20−00 (2022)
valuescouldoccurforrefractorymaterialshavingapotentialto 5.2.2 After the boiling period, cool the test specimens to
form hydrated species with water. room temperature while still completely covered with water.
After boiling keep the specimens immersed in water for a
3.5 Certain precautions must be exercised in interpreting
minimum of 12 h before weighing.
and using results from these test methods. All four property
values are interrelated by at least two of the three base data
5.3 Suspended Weight, S:
values generated during testing.Thus, an error in any base data
5.3.1 Determine the weight, S, of each test specimen after
value will cause an error in at least three of the property values
boiling and while suspended in water in grams to the nearest
for a given test specimen. Certain of the properties, that is,
0.1 g.
apparent specific gravity and bulk density, are functions of
5.3.2 This weighing is usually accomplished by suspending
other factors such as product composition, compositional
the specimen in a loop or halter ofAWG gauge 22 (0.643-mm)
variability within the same product, impervious porosity, and
copper wire hung from one arm of the balance. The balance
total porosity. Generalizations on or comparisons of property
shall be previously counter-balanced with the wire in place and
values should only be judiciously made between like products
immersed in water to the same depth as is used when the
tested by these test methods or with full recognition of
refractory specimens are in place.
potentially inherent differences between the products being
5.4 Saturated Weight, W—After determining the suspended
compared or the test method used.
weight, blot each specimen lightly with a moistened smooth
linen or cotton cloth to remove all drops of water from the
4. Test Specimens
surface and determine the saturated weight, W, in grams by
4.1 When testing 9-in. (228-mm) straight brick, use a
weighing in air to the nearest 0.1 g. Perform the blotting
quarter-brick specimen by halving the brick along a plane
operation by rolling the specimen lightly on the wet cloth,
parallel to the 9 by 2 ⁄2 or 3-in. (228 by 64 or 76-mm) face and
which has previously been saturated with water, and then press
1 1
along a plane parallel to the 4 ⁄2 by 2 ⁄2 or 3-in. (114 by 64 or
only enough to remove such water as will drip from the cloth.
76-mm) face. Four of the surfaces of the resultant quarter-brick
Excessive blotting will induce error by withdrawing water
specimen include part of the original molded faces.
from the pores of the specimen.
4.2 When testing other refractory shapes, cut, drill, or break
from each shape a specimen having volume of approximately
6. C
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