ASTM C133-1997(2008) Standard Test Methods for Cold Crushing Strength and Modulus of Rupture of Refractories.pdf

1、Designation: C 133 97 (Reapproved 2008)Standard Test Methods forCold Crushing Strength and Modulus of Rupture ofRefractories1This standard is issued under the fixed designation C 133; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,

2、 the year of last revision. A number 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 Department of Defense.1. Scope1.1 These test methods cover

3、 the determination of the coldcrushing strength and the modulus of rupture (MOR) of driedor fired refractory shapes of all types.1.2 The test methods appear in the following sections:Test Method SectionsCold Crushing Strength 4 to 9Modulus of Rupture 10 to 151.3 The values stated in inch-pound units

4、 are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibil

5、ity of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 862 Practice for Preparing Refractory Concrete Speci-mens by CastingC 1054 Practice for Pressing

6、 and Drying Refractory Plasticand Ramming Mix SpecimensE4 Practices for Force Verification of Testing Machines3. Significance and Use3.1 The cold strength of a refractory material is an indica-tion of its suitability for use in refractory construction. (It is nota measure of performance at elevated

7、temperatures.)3.2 These test methods are for determining the room tem-perature flexural strength in 3-point bending (cold modulus ofrupture) or compressive strength (cold crushing strength), orboth, for all refractory products.3.3 Considerable care must be used to compare the resultsof different det

8、erminations of the cold crushing strength ormodulus of rupture. The specimen size and shape, the nature ofthe specimen faces (that is, as-formed, sawed, or ground), theorientation of those faces during testing, the loading geometry,and the rate of load application, may all significantly affect thenu

9、merical results obtained. Comparisons of the results betweendifferent determinations should not be made if one or more ofthese parameters differ between the two determinations.3.4 The relative ratio of the largest grain size to the smallestspecimen dimension may significantly affect the numericalres

10、ults. For example, smaller, cut specimens containing largegrains may present different results than the bricks from whichthey were cut. Under no circumstances should 6- by 1- by 1-in.(152- by 25- by 25-mm) specimens be prepared and tested formaterials containing grains with a maximum grain dimension

11、exceeding 0.25 in. (6.4 mm).3.5 This test method is useful for research and development,engineering application and design, manufacturing processcontrol, and for developing purchasing specifications.COLD CRUSHING STRENGTH4. Apparatus4.1 Testing MachineAny form of standard mechanical orhydraulic comp

12、ression testing machine conforming to therequirements of Practices E4may be used.1These test methods are under the jurisdiction of ASTM Committee C08 onRefractories and are the direct responsibility of Subcommittee C08.01 on Strength.Current edition approved Aug. 1, 2008. Published September 2008. O

13、riginallyapproved in 1937. Last previous edition approved in 2003 as C 133 97 (2003).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary

14、page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 1For low-strength materials (such as insulating bricks orcastables), a sensitivity of 20 lbf (67 kN) or less is required. The use of ahydraulic testing mach

15、ine is also preferred over the mechanical type forthese materials.4.2 Spherical Bearing BlockThe plane surface of thespherical bearing block (see Fig. 1) shall have an area which isequal to or greater than the cross section of the test specimen.5. Test Specimens5.1 Brick and Shapes (bulk density gre

16、ater than 100 lb/ft3(1.60 g/cm3)The test specimens shall be 2-in. (51-mm)cubes or cylinders, 2 in. (51 mm) in diameter by 2 in. (51 mm)high. The height should be parallel to the original direction ofpressing of the brick or shape. In the case of special shapes,only one specimen shall be cut from a s

17、ingle shape and asmany of the original surfaces as possible shall be preserved. Inpreparing specimens from irregular or large refractory shapes,any method involving the use of abrasives, such as a high-speed abrasion wheel, core drill, or rubbing bed, that willproduce a specimen with approximately p

18、lane and parallelsides without weakening the structure of the specimen may beused.5.2 Insulating Brick or Shapes (typical bulk density of 100lb/ft3(1.60 g/cm3), or greater than 45 % total porosity, orboth)The test specimens shall be 412 by 412 by 212 or 3 in.(114 by 114 by 64 or 76 mm), each taken f

19、rom a different brick.It is permissible to prepare these specimens from the half-brickresulting from the modulus of rupture test (see Sections 10-15).The selected compression test section shall be free of cracks,chipped surfaces, and other obvious defects. The test surfacesshall be approximately par

20、allel planes.5.3 Castable RefractoriesThe test specimens shall be 2-by 2- by 2-in. (51- by 51- by 51-mm) cubes or cylinders 2 in.(51 mm) in diameter by 2 in. (51 mm) high, prepared bycasting or gunning. It is permissible to prepare one specimenfrom each 9- by 2- by 2-in. (230- by 51- by 51-mm) bar a

21、fterthe modulus of rupture test (see Sections 10-15). The selectedcompression test section shall be free of cracks, chippedsurfaces, and other obvious defects. The loaded surfaces shallbe approximately parallel planes. All samples must be dried at220 to 230F (105 to 110C) for 18 h (overnight). Uponr

22、emoval from the oven, allow the sample to cool naturally untilcool to the touch. Complete testing within2hofremoval fromthe drying oven. (See Practices C 862 and C 1054.)6. Procedure6.1 At least five specimens from an equivalent number ofrefractory shapes compose a sample.NOTE 2For relatively weak s

23、pecimens like insulating castables orinsulating firebricks, a minimum sample size of ten specimens is pre-ferred.6.2 Brick and ShapesPlace a cellulose fiber wall board(for example, Masonite3) 0.25 in. (6.4 mm) in thickness andextending 0.5 in. (12.7 mm) or more beyond the edges of theloaded faces of

24、 the specimen. Apply the load parallel to thedirection in which the brick was originally pressed.6.3 Regular and High Strength CastablesPlace a cellulosefiber wall board 0.25 in. (6.4 mm) in thickness and extending0.5 in. (12.7 mm) or more beyond the edges of the loaded facesof the specimen. Apply t

25、he load on the 2- by 2-in. (51- by51-mm) or 2-in. (51-mm) diameter face and perpendicular tothe depth of the specimen as originally cast or gunned.6.4 Insulating Brick or ShapesApply the load directly tothe 412-by412-in. (114- by 114-mm) surface of the testspecimen.6.5 Insulating Castables (typical

26、bulk density of 100 lb/ft3(1.60 g/cm3), or greater than 45 % total porosity, or both)Apply the load directly to the 2- by 2-in. (51- by 51-mm) faceand perpendicular to the depth of the specimen as originallycast or gunned.6.6 Use the bearing block on top of the test specimen, andposition it so that

27、the center of the sphere is in alignment withthe vertical axis of the specimen (see Fig. 1). Keep thespherical bearing block thoroughly lubricated to ensure accu-rate adjustment which may be made by hand under a smallinitial load for each specimen.NOTE 3The spherical bearing block may not be necessa

28、ry on testmachines having mechanical linkages which ensure that the stress appliedis colinear with the axis of the specimen.6.7 For dense refractories with sufficient strength to requiregreater than about 3 min per test, initial loading to one-half ofthe anticipated failure load may be accomplished

29、at anyconvenient rate exceeding the specified rate. Subsequently,each specimen shall be crushed with a compressive loadapplied at the standard rates specified in Table 1. The rates shallnot vary by more than 610 % of the specified rate for the typeof refractory being tested.6.8 When using a mechanic

30、al testing machine, keep thebalance beam in a constantly floating position.6.9 Specimens are loaded, as specified, to failure. Failure isdefined as the collapse of the specimen (failure to support theload), or the reduction of the specimen height to 90 % of itsoriginal value. The maximum applied loa

31、d is recorded.7. Calculation7.1 Calculate the cold crushing strength using Eq 1:3Masonite has been found satisfactory for this purpose.FIG. 1 Recommended Design for Crushing Test Assembly,Including Bearing BlockC 133 97 (2008)2S 5 W/A (1)where:S = cold crushing strength, lbf/in.2(MPa),W = total maxi

32、mum load indicated by the testing machine,lbf (N), andA = average of the areas of the top and bottom of thespecimen perpendicular to the line of application ofthe load, in.2(mm2).8. Report8.1 Report the following:8.1.1 Designation of the materials tested (that is, manufac-turer, brand, description,

33、lot number, etc.);8.1.2 Specimen configuration, including size, shape, loca-tion in the original brick or shape, the character of the faces(that is, cut, drilled, as-pressed, as-cast, etc.), and the specimenorientation during testing;8.1.3 Pretreatment, if any, given to the test pieces (forexample,

34、curing, firing, coking, etc.);8.1.4 Number of specimens in a sample;8.1.5 Individual specimen dimensions, the maximum ap-plied load, and the calculated cold crushing strength for eachspecimen (see 7.1);8.1.6 Mean cold crushing strength and standard deviationfor each sample.9. Precision and Bias9.1 P

35、recisionThe precision of this test method is currentlybeing investigated.9.2 BiasNo justifiable statement can be made on the biasof the test method for measuring the cold crushing strength ofrefractories, because the value of cold crushing strength can bedefined only in terms of a test method.MODULU

36、S OF RUPTURE10. Apparatus10.1 Testing MachineAny form of standard mechanical orhydraulic compression testing machine conforming to therequirements of Practices E4may be used.NOTE 4Properly calibrated portable apparatus may be used.10.2 Bearing Surfaces, that shall have a radius of curvatureof58 in.

37、16 mm) or be cylindrical pieces 114-in. (32-mm) indiameter. For 6- by 1- by 1-in. (152- by 25- by 25-mm)specimens, the radius of curvature shall be316 in. (5 mm) orcylindrical pieces38 in. (10 mm) in diameter. All such bearingsurfaces shall be straight and of a length at least equal to thewidth of

38、the test specimen. The supporting members for thelower bearing surfaces shall be constructed so as to provide ameans for the alignment of the bearing surfaces with the undersurface of the test specimen because the test brick may have alongitudinal twist. Apparatus of the design shown in Fig. 2 isrec

39、ommended, although other types may be used, providedthey conform to these requirements. A satisfactory alternativedesign is shown in Fig. 3.11. Test Specimens11.1 Brick and Shapes (bulk density greater than 100 lb/ft3(1.60 g/cm3)The preferred test specimens shall be standard9- by 412-by212- or 3-in.

40、 (228- by 114- by 64- or 76-mm)bricks, or specimens of equivalent size ground or cut fromrefractory shapes. In the case of special shapes, only onespecimen shall be cut from a single shape. As many originalsurfaces as possible shall be preserved. Where brick sizes areimpossible or impracticable, alt

41、ernative specimen sizes of 9 by2 by 2 in. (228 by 51 by 51 mm) or 6 by 1 by 1 in. (152 by 25by 25 mm) may be prepared. In preparing specimens fromirregular or larger shapes, any method involving the use ofabrasives, such as a high-speed abrasion wheel or rubbing bed,TABLE 1 Standard Loading Rates fo

42、r Cold Crushing StrengthRefractory Type Size, in. (mm)Loaded CrossSection, in. (mm)Loaded Area, in.2mm2)Stress Rate,lbf/in.2/min(MPa/min)Loading Rate,lbf/min (kN/min)Strain Rate,Ain./min (mm/min)Refractory Brick and ShapesDensity 100 lb/ft3(1.60 gm/cm3), or45 % true porosity, or both4.5 3 4.5 3 2.5C

43、D(114 3 114 3 64)4.5 3 4.5(114 3 114)20.25(13 064)435(3)8809(39)0.05(1.3)(Includes dried, unfired plastic or rammedrefractories)4.5 3 4.5 3 3C,D(114 3 114 3 76)4.5 3 4.5(114 3 114)20.25(13 064)435(3)8809(39)0.05(1.3)2 3 2 3 2D,E(51 3 51 3 51)2 3 2(51 3 51)4(2601)435(3)1740(7.80)0.05(1.3)2 diameter

44、3 2E2, diameter 3.14 435 1367 0.05(51 diameter 3 51) (51, diameter) (2027) (3) (6.08) (1.3)AWhere possible, loading at a constant stress rate is preferable to constant strain rate loading.BFor dense refractory brick and shapes requiring more than a 3-min test duration, specimens may be loaded to one

45、 half of the anticipated fracture strength at anyconvenient rate exceeding that specified.CThese sizes are preferred for insulating firebricks.DThese pieces may be cut from broken halves of MOR specimens.EThese sizes are preferred for insulating castables.C 133 97 (2008)3that will produce a specimen

46、 with approximately plane andparallel sides without weakening the structure may be used.11.2 Insulating Brick or Shapes (typical bulk density of 100lb/ft3(1.60 g/cm3), or total porosity greater than 45 %, orboth)The test specimens shall be whole brick measuring 9 by412 by 212 or 3 in. (228 by 114 by

47、 64 or 76 mm), or specimensof equivalent size cut from larger shapes.11.3 Castable RefractoriesThe test specimens shall be 9-by 2- by 2-in. (228- by 51- by 51-mm) bars prepared by castingor gunning. The top and bottom, and the side faces, respec-tively, shall be approximately parallel planes.All sam

48、ples mustbe dried at 220 to 230F (105 to 110C) for 18 h (overnight).Upon removal from the oven, allow the sample to coolnaturally until cool to the touch. Complete testing within2hofremoval from the drying oven. (See Practices C 862 andC 1054.)12. Procedure12.1 At least five specimens from an equiva

49、lent number ofrefractory shapes compose a sample.NOTE 5For relatively weak specimens like insulating refractories, aminimum sample size of ten specimens is preferred.12.2 Place a test specimen flat on the bearing cylinders witha span as specified in Table 2 and with the load applied atmid-span. Whenever possible, use an original, unbrandedsurface of a brick or shape as the tension face, that is, the facein contact with the two bottom bearing cylinders. For castablepieces, the depth dimension of the specimen as originally castor gunned is horiz