ASTM C133-97

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

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 Modulus of Rupture 10 to 15
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Dec-1996
• Technical Committee: C08 - Refractories
• Drafting Committee: C08.01 - Strength

Relations

• Replaced By: ASTM C133-97(2003) - Standard Test Methods for Cold Crushing Strength and Modulus of Rupture of Refractories
• Effective Date: 10-Apr-2003
• Referred By: ASTM C607-88(2016) - Standard Practice for Coking Large Shapes of Carbon-Bearing Materials
• Effective Date: 01-Jan-1997
• Referred By: ASTM C401-12(2022) - Standard Classification of Alumina and Alumina-Silicate Castable Refractories
• Effective Date: 01-Jan-1997
• Referred By: ASTM C1685-15(2021) - Standard Specification for Pneumatically Applied High-Temperature Fiber Thermal Insulation for Industrial Applications
• Effective Date: 01-Jan-1997
• Referred By: ASTM F1097-17(2022) - Standard Specification for Mortar, Refractory (High-Temperature, Air-Setting)
• Effective Date: 01-Jan-1997
• Referred By: ASTM C416-97(2022) - Standard Classification of Silica Refractory Brick
• Effective Date: 01-Jan-1997
• Referred By: ASTM F1312-19(2023) - Standard Specification for Brick, Insulating, High Temperature, Fire Clay
• Effective Date: 01-Jan-1997
• Referred By: ASTM C1190-18(2022) - Standard Practice for Location of Test Specimens from Magnesia-Carbon and Impregnated Burned Basic Brick
• Effective Date: 01-Jan-1997
• Referred By: ASTM C203-22 - Standard Test Methods for Breaking Load and Flexural Properties of Block-Type Thermal Insulation
• Effective Date: 01-Jan-1997
• Referred By: ASTM C198-09(2019) - Standard Test Method for Cold Bonding Strength of Refractory Mortar
• Effective Date: 01-Jan-1997
• Referred By: ASTM C27-98(2022) - Standard Classification of Fireclay and High-Alumina Refractory Brick
• Effective Date: 01-Jan-1997
• 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-Jan-1997
• Referred By: ASTM C862-16(2020) - Standard Practice for Preparing Refractory Concrete Specimens by Casting
• Effective Date: 01-Jan-1997

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: C 133 – 97
Standard Test Methods for
Cold Crushing Strength and Modulus of Rupture of
Refractories
This standard is issued under the fixed designation C 133; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
e NOTE—Approved actions inadvertently omitted were added editorially January 22, 1997.
1. Scope 3.3 Considerable care must be used to compare the results
of different determinations of the cold crushing strength or
1.1 These test methods cover the determination of the cold
modulus of rupture. The specimen size and shape, the nature of
crushing strength and the modulus of rupture (MOR) of dried
the specimen faces (that is, as-formed, sawed, or ground), the
or fired refractory shapes of all types.
orientation of those faces during testing, the loading geometry,
1.2 The test methods appear in the following sections:
and the rate of load application, may all significantly affect the
Test Method Sections
numerical results obtained. Comparisons of the results between
Cold Crushing Strength 4 to 9
different determinations should not be made if one or more of
Modulus of Rupture 10 to 15
these parameters differ between the two determinations.
1.3 The values stated in inch-pound units are to be regarded 3.4 The relative ratio of the largest grain size to the smallest
as the standard. The values given in parentheses are for
specimen dimension may significantly affect the numerical
information only.
results. For example, smaller, cut specimens containing large
1.4 This standard does not purport to address all of the grains may present different results than the bricks from which
safety concerns, if any, associated with its use. It is the
they were cut. Under no circumstances should 6- by 1- by 1-in.
responsibility of the user of this standard to establish appro- (152- by 25- by 25-mm) specimens be prepared and tested for
priate safety and health practices and determine the applica-
materials containing grains with a maximum grain dimension
bility of regulatory limitations prior to use. exceeding 0.25 in. (6.4 mm).
3.5 This test method is useful for research and development,
2. Referenced Documents
engineering application and design, manufacturing process
2.1 ASTM Standards:
control, and for developing purchasing specifications.
C 862 Practice for Preparing Refractory Concrete Speci-
COLD CRUSHING STRENGTH
mens by Casting
C 1054 Practice for Pressing and Drying Refractory Plastic
4. Apparatus
and Ramming Mix Specimens
4.1 Testing Machine—Any form of standard mechanical or
E 4 Practices for Force Verification of Testing Machines
hydraulic compression testing machine conforming to the
3. Significance and Use requirements of Practices E 4 may be used.
3.1 The cold strength of a refractory material is an indica-
NOTE 1—For low-strength materials (such as insulating bricks or
tion of its suitability for use in refractory construction. (It is not
castables), a sensitivity of 20 lbf (67 kN) or less is required. The use of a
a measure of performance at elevated temperatures.) hydraulic testing machine is also preferred over the mechanical type for
these materials.
3.2 These test methods are for determining the room tem-
perature flexural strength in 3-point bending (cold modulus of
4.2 Spherical Bearing Block—The plane surface of the
rupture) or compressive strength (cold crushing strength), or
spherical bearing block (see Fig. 1) shall have an area which is
both, for all refractory products.
equal to or greater than the cross section of the test specimen.
5. Test Specimens
These test methods are under the jurisdiction of ASTM Committee C-8 on
5.1 Brick and Shapes (bulk density greater than 100 lb/ft
Refractories and are the direct responsibility of Subcommittee C08.01 on Strength.
Current edition approved Jan. 22, 1997. Published March 1997. Originally
(1.60 g/cm ))—The test specimens shall be 2-in. (51-mm)
published as C 133 – 37 T. Last previous edition C 133 – 96.
cubes or cylinders, 2 in. (51 mm) in diameter by 2 in. (51 mm)
Annual Book of ASTM Standards, Vol 15.01.
3 high. The height should be parallel to the original direction of
Annual Book of ASTM Standards, Vol 03.01.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
C 133–97
NOTE 2—For relatively weak specimens like insulating castables or
insulating firebricks, a minimum sample size of ten specimens is pre-
ferred.
6.2 Brick and Shapes—Place a cellulose fiber wall board
(for example, Masonite ) 0.25 in. (6.4 mm) in thickness and
extending 0.5 in. (12.7 mm) or more beyond the edges of the
loaded faces of the specimen. Apply the load parallel to the
direction in which the brick was originally pressed.
6.3 Regular and High Strength Castables—Place a cellulose
fiber wall board 0.25 in. (6.4 mm) in thickness and extending
0.5 in. (12.7 mm) or more beyond the edges of the loaded faces
of the specimen. Apply the load on the 2- by 2-in. (51- by
51-mm) or 2-in. (51-mm) diameter face and perpendicular to
the depth of the specimen as originally cast or gunned.
6.4 Insulating Brick or Shapes—Apply the load directly to
1 1
the 4 ⁄2-by4 ⁄2-in. (114- by 114-mm) surface of the test
FIG. 1 Recommended Design for Crushing Test Assembly,
specimen.
Including Bearing Block
6.5 Insulating Castables (typical bulk density of 100 lb/ft
(1.60 g/cm ), or greater than 45 % total porosity, or both)—
pressing of the brick or shape. In the case of special shapes,
Apply the load directly to the 2- by 2-in. (51- by 51-mm) face
only one specimen shall be cut from a single shape and as
and perpendicular to the depth of the specimen as originally
many of the original surfaces as possible shall be preserved. In
cast or gunned.
preparing specimens from irregular or large refractory shapes,
6.6 Use the bearing block on top of the test specimen, and
any method involving the use of abrasives, such as a high-
position it so that the center of the sphere is in alignment with
speed abrasion wheel, core drill, or rubbing bed, that will
the vertical axis of the specimen (see Fig. 1). Keep the
produce a specimen with approximately plane and parallel
spherical bearing block thoroughly lubricated to ensure accu-
sides without weakening the structure of the specimen may be
rate adjustment which may be made by hand under a small
used.
initial load for each specimen.
5.2 Insulating Brick or Shapes (typical bulk density of 100
3 3
NOTE 3—The spherical bearing block may not be necessary on test
lb/ft (1.60 g/cm ), or greater than 45 % total porosity, or
machines having mechanical linkages which ensure that the stress applied
1 1 1
both)—The test specimens shall be 4 ⁄2 by 4 ⁄2 by 2 ⁄2 or 3 in.
is colinear with the axis of the specimen.
(114 by 114 by 64 or 76 mm), each taken from a different brick.
6.7 For dense refractories with sufficient strength to require
It is permissible to prepare these specimens from the half-brick
greater than about 3 min per test, initial loading to one-half of
resulting from the modulus of rupture test (see Sections 10-15).
the anticipated failure load may be accomplished at any
The selected compression test section shall be free of cracks,
convenient rate exceeding the specified rate. Subsequently,
chipped surfaces, and other obvious defects. The test surfaces
each specimen shall be crushed with a compressive load
shall be approximately parallel planes.
applied at the standard rates specified in Table 1. The rates shall
5.3 Castable Refractories—The test specimens shall be 2-
not vary by more than 610 % of the specified rate for the type
by 2- by 2-in. (51- by 51- by 51-mm) cubes or cylinders 2 in.
of refractory being tested.
(51 mm) in diameter by 2 in. (51 mm) high, prepared by
6.8 When using a mechanical testing machine, keep the
casting or gunning. It is permissible to prepare one specimen
balance beam in a constantly floating position.
from each 9- by 2- by 2-in. (230- by 51- by 51-mm) bar after
6.9 Specimens are loaded, as specified, to failure. Failure is
the modulus of rupture test (see Sections 10-15). The selected
defined as the collapse of the specimen (failure to support the
compression test section shall be free of cracks, chipped
load), or the reduction of the specimen height to 90 % of its
surfaces, and other obvious defects. The loaded surfaces shall
original value. The maximum applied load is recorded.
be approximately parallel planes. All samples must be dried at
220 to 230°F (105 to 110°C) for 18 h (overnight). Upon
7. Calculation
removal from the oven, allow the sample to cool naturally until
7.1 Calculate the cold crushing strength using Eq 1:
cool to the touch. Complete testing within2hof removal from
the drying oven. (See Practices C 862 and C 1054.) S 5 W/A (1)
6. Procedure
6.1 At least five specimens from an equivalent number of
refractory shapes compose a sample. Masonite has been found satisfactory for this purpose.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
C 133–97
TABLE 1 Standard Loading Rates for Cold Crushing Strength
Stress Rate,
2 A
Loaded Cross Loaded Area, in. Loading Rate, Strain Rate,
Refractory Type Size, in. (mm) lbf/in. /min
Section, in. (mm) mm ) lbf/min (kN/min) in./min (mm/min)
(MPa/min)
Refractory Brick and Shapes
3 3 B B B
Density >100 lb/ft (>1.60 gm/cm ), or 2 3 2 3 2 2 3 2 4 1750 7000 0.05
<45 % true porosity, or both (51 3 51 3 51) (51 3 51) (2601) (12) (31.2) (1.3)
B B B
(Includes regular or high strength castables 2 diameter 3 2 2, diameter 3.14 1750 5500 0.05
and fired plastic or rammed refractories) (51 diameter 3 51) (51, diameter) (2027) (12) (24.3) (1.3)
Insulating Refractories
3 3 C,D
Density <100 lb/ft (<1.60 gm/cm ), or 4.5 3 4.5 3 2.5 4.5 3 4.5 20.25 435 8809 0.05
>45 % true porosity, or both (114 3 114 3 64) (114 3 114) (13 064) (3) (39) (1.3)
CD
(Includes dried, unfired plastic or rammed 4.5 3 4.5 3 3 4.5 3 4.5 20.25 435 8809 0.05
refractories) (114 3 114 3 76) (114 3 114) (13 064) (3) (39) (1.3)
D,E
2 3 2 3 2 2 3 2 4 435 1740 0.05
(51 3 51 3 51) (51 3 51) (2601) (3) (7.80) (1.3)
E
2 diameter 3 2 2, diameter 3.14 435 1367 0.05
(51 diameter 3 51) (51, diameter) (2027) (3) (6.08) (1.3)
A
Where possible, loading at a constant stress rate is preferable to constant strain rate loading.
B
For dense refractory brick and shapes requiring more than a 3-min test duration, specimens may be loaded to one half of the anticipated fracture strength at any
convenient rate exceeding that specified.
C
These sizes are preferred for insulating firebricks.
D
These pieces may be cut from broken halves of MOR specimens.
E
These sizes are preferred for insulating castables.
MODULUS OF RUPTURE
where:
10. Apparatus
S = cold crushing strength, lbf/in. (MPa),
W = total maximum load indicated by the testing machine,
10.1 Testing Machine—Any form of standard mechanical or
lbf (N), and
hydraulic compression testing machine conforming to the
A = average of the areas of the top and bottom of the
requirements of Practices E 4 may be used.
specimen perpendicular to the line of application of
NOTE 4—Properly calibrated portable apparatus may be used.
2 2
the load, in. (mm ).
10.2 Bearing Surfaces, that shall have a radius of curvature
5 1
of ⁄8 in. (16 mm) or be cylindrical pieces 1 ⁄4-in. (32-mm) in
8. Report
diameter. For 6- by 1- by 1-in. (152- by 25- by 25-mm)
8.1 Report the following:
specimens, the radius of curvature shall be ⁄16 in. (5 mm) or
8.1.1 Designation of the materials tested (that is, manufac-
cylindrical pieces ⁄8 in. (10 mm) in diameter. All such bearing
turer, brand, description, lot number, etc.);
surfaces shall be straight and of a length at least equal to the
width of the test specimen. The supporting members for the
8.1.2 Specimen configuration, including size, shape, loca-
lower bearing surfaces shall be constructed so as to provide a
tion in the original brick or shape, the character of the faces
means for the alignment of the bearing surfaces with the under
(that is, cut, drilled, as-pressed, as-cast, etc.), and the specimen
surface of the test specimen because the test brick may have a
orientation during testing;
longitudinal twist. Apparatus of the design shown in Fig. 2 is
8.1.3 Pretreatment, if any, given to the test pieces (for
recommended, although other types may be used, provided
example, curing, firing, coking, etc.);
they conform to these requirements. A satisfactory alternative
8.1.4 Number of specimens in a sample;
design is shown in Fig. 3.
8.1.5 Individual specimen dimensions, the maximum ap-
11. Test Specimens
plied load, and the calculated cold crushing strength for each
specimen (see 7.1);
11.1 Brick and Shapes (bulk density greater than 100 lb/ft
(1.60 g/cm )—The preferred test specimens shall be standard
8.1.6 Mean cold crushing strength and standard deviation
1 1
9- by 4 ⁄2-by2 ⁄2- or 3-in. (228- by 114- by 64- or 76-mm)
for each sample.
bricks, or specimens of equivalent size ground or cut from
refractory shapes. In the case of special shapes, only one
9. Precision and Bias
specimen shall be cut from a single shape. As many original
9.1 Precision—The precision of this test method is currently
surfaces as possible shall be preserved. Where brick sizes are
being investigated.
impossible or impracticable, alternative specimen sizes of 9 by
9.2 Bias—No justifiable statement can be made on the bias
2 by 2 in. (228 by 51 by 51 mm) or 6 by 1 by 1 in. (152 by 25
of the test method for measuring the cold crushing strength of
by 25 mm) may be prepared. In preparing specimens from
refractories, because the value of cold crushing strength can be irregular or larger shapes, any method involving the use of
defined only in terms of a test method. abrasives, such as a high-speed abrasion wheel or rubbing bed,
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
C 133–97
NOTE 1—The dimensions appearing in Fig. 2 are in inches. See table below for metric equivalents.
Me
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