1、Designation: C880/C880M 15Standard Test Method forFlexural Strength of Dimension Stone1This standard is issued under the fixed designation C880/C880M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A num
2、ber in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the procedure for determiningthe flexural strength of stone by use of a simple beam usingquarter-point loading.1.2
3、 Stone tests shall be made when pertinent for the situa-tion when the load is perpendicular to the bedding plane andwhen the load is parallel to the bedding plane.1.3 As required, the flexural tests shall also be conductedunder wet conditions.1.4 The values stated in either SI units or inch-pound un
4、itsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 This standard does not purport to addres
5、s all of thesafety concerns, if any, associated with its use. It is theresponsibility 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:2E4 Practices for
6、 Force Verification of Testing MachinesC119 Terminology Relating to Dimension StoneC1799 Guide to Dimension Stone Test Specimen Samplingand Preparation3. Terminology3.1 DefinitionsAll definitions are in accordance with Ter-minology C119.4. Significance and Use4.1 This test method is useful in indica
7、ting the differences inflexural strength between the various dimension stones. Thistest method also provides one element in comparing stones ofthe same type.5. Apparatus5.1 Testing Machine (Fig. 1), conforming to the require-ments of the applicable sections of Practices E4. The quarter-point loading
8、 method shall be used in making flexure tests ofstone employing bearing blocks which will ensure that forcesapplied to the beam will be vertical only and applied withouteccentricity. The apparatus should be capable of maintainingthe span length and distances between load-applying blocksand support b
9、locks constant within 60.05 in. 61 mm. Theload should be capable of being applied at a uniform rate andin such a manner as to avoid shock.6. Sampling6.1 Select the sample to represent a true average of the typeor grade of stone under consideration and of the qualitysupplied to the market under the t
10、ype designation to be tested.The sample may be selected by the purchaser or his authorizedrepresentative from the quarried stone or taken from the naturalledge and shall be of adequate size to permit the preparation ofthe desired number of test specimens. When perceptiblevariations occur, the purcha
11、ser may select as many samples asare necessary for determining the variations in flexuralstrength.NOTE 1Refer to Guide C1799 for additional information on selecting,preparing, and conditioning test specimens.7. Test Specimen7.1 The test specimens shall measure 4 in. 100 mm wideby 1.25 in. 30 mm thic
12、k by 15 in. 350 mm long, with a spanas tested of 12.5 in. 300 mm. The sides of the specimen shallbe at right angles with the top and bottom. The specimens shallhave a fine abrasive finish on the planes perpendicular to theload and a fine saw finish on the other four planes. Thedimensions of the spec
13、imen shall be measured and recorded tothe nearest 0.01 in. 0.1 mm. A minimum of five specimensshall be tested for each condition of test. The average value ofthe test results is reported as the flexural strength of the stone.1This test method is under the jurisdiction of ASTM Committee C18 onDimensi
14、on Stone and is the direct responsibility of Subcommittee C18.01 on TestMethods.Current edition approved May 1, 2015. Published July 2015. Originally approvedin 1978. Last previous edition approved in 2009 as C88009. DOI: 10.1520/C0880_C0880M-15.2For referenced ASTM standards, visit the ASTM website
15、, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17
16、.2 Where this test method is specified in the physicalrequirements of an ASTM C18 Standard Specification for adimension stone, the test specimens shall meet the require-ments under 7.1.7.3 Where the job thickness has been set (for example, thethickness of the stone panels for the project has beenest
17、ablished), it is often requested to perform flexure tests at thejob thickness. The following shall govern the specimen sizewhere it is requested to test at the job thickness and the jobthickness is other than 1.25 in. 30 mm. The span as testedshall be 10 times the thickness. The specimen lengths sha
18、ll benot less than 2 in. 50 mm and not more than 4 in. 100 mmgreater than the span as tested. Where the thickness is less than2.67 in. 70 mm, the width of the specimen shall be 4 in. 100mm. Where the thickness is greater than 2.67 in. 70 mm thewidth shall be 1.5 times the thickness. Where the thickn
19、ess isother than 1.25 in. 30 mm and the specimen size is inaccordance with the job thickness criteria noted in theforegoing, the average value of the test results shall be reportedas the flexural strength of the stone at the job thickness. Allother requirements shall be in accordance with 7.1.7.4 Wh
20、ere the job surface finish has been set (for example,the architectural finish on the panels for the project has beenestablished), it is often requested to perform flexure tests onspecimens with the finish the same as on the job. The followingshall govern when it is requested to test at the job surfa
21、cefinish. The specimens shall have a finish on one planeperpendicular to the load in accordance with the finish speci-fied for the job. Unless there is data to the contrary, thepositioning of the specimen should be with the finished face inflexural tension. The average value of the test results shal
22、l bereported as the flexural strength of the stone at the job surfacefinish. All other requirements shall be in accordance with 7.1and 7.3.7.5 Where the specimens conform to the requirements of 7.3and 7.4, the average value of the test results shall be reportedas the flexural strength of the stone a
23、t the job thickness andsurface finish.7.6 Test results obtained by this test method are those offlexural strength properties. In specific applications, test speci-mens of different geometry may give useful results in terms ofa modulus of rupture value.8. Conditioning8.1 Before testing the specimens
24、in a dry condition, drythem for 48 h at 140 6 4F 60 6 2C. At the 46th, 47th and48th hour, weigh the specimens to ensure that the weight is thesame. If the weight continues to drop, continue to dry thespecimens until there are three successive hourly readings withthe same weight. After removing the s
25、pecimens from the oven,cool them to room temperature in a desiccator before testingthem.8.2 Before testing the specimens in a wet condition, im-merse them in water for 48 h at 72 6 4F 22 6 2C. Testthem immediately upon removal from the bath, wiping thespecimens free of surface water.9. Procedure9.1
26、Assemble the apparatus and place the specimen on thespan supports and adjust the quarter point loading blocks intocontact with the specimen.9.2 Apply the load at a uniform stress rate of 600 psi/min4 MPa to failure.10. Calculation10.1 Calculate the flexural strength, as follows: 53WL4bd2(1)where: =
27、flexural strength, psi MPa,W = maximum load, lbf N,L = span, in. mm,L =10d,b = width of specimen, in. mm, b 1.5d, andd = depth of specimen, in. mm.11. Report11.1 The report shall include the following:11.1.1 Stone type.11.1.2 Sizes of the specimens used.11.1.3 Preconditioning procedure used.11.1.4 I
28、ndividual test results for each specimen.11.1.5 Average value of the test results for each group usingthe following relation:NOTE 1Apparatus may be used inverted.FIG. 1 Diagrammatic View of a Suitable Apparatus for Flexure Test of StoneC880/C880M 152 5sum of observed valuesnumber of tests11.1.6 Stan
29、dard deviation, s, of the test results for eachgroup using the following relation:s 5sum ofobserved value 2 !2number of tests 2 111.1.7 Any variations from the above procedural tech-niques.11.2 The following additional information shall also bereported: identification of the sample, including name a
30、ndlocation of the quarry, name and position of the ledge, datewhen sample was taken, and trade name or grade of the slate.12. Precision and Bias12.1 Individual variations in a natural product may result indeviation from accepted values. A precision section will beadded when sufficient data are avail
31、able to indicate acceptabletolerances in repeatability and reproducibility.13. Keywords13.1 dimension stone; flexural strength; flexure; stone; testASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users
32、of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every fi
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35、A 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 153
