1、Designation: C 880/C 880M 09Standard Test Method forFlexural Strength of Dimension Stone1This standard is issued under the fixed designation C 880/C 880M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A
2、 number 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
3、.1.2 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 UnitsThe values stated in either SI units or inch
4、-pound units are to be regarded separately as standard. Thevalues stated in each system may not be exact equivalents;therefore, each system shall be used independently of the other.Combining values from the two systems may result in non-conformance with the standard.1.5 This standard does not purpor
5、t to address 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 Pr
6、actices for Force Verification of Testing MachinesC119 Terminology Relating to Dimension Stone3. Terminology3.1 DefinitionsAll definitions are in accordance with Ter-minology C119.4. Significance and Use4.1 This test method is useful in indicating the differences inflexural strength between the vari
7、ous 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 method shall be used in making flexure tests ofstone emp
8、loying 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 blocks constant within 60.05 in. 61 mm. Theload should be
9、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 type designation to be tested.The sample may be selected b
10、y 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 purchaser may select as many samples asare necessary for determ
11、ining the variations in flexuralstrength.7. Test Specimen7.1 The test specimens shall measure 4 in. 100 mm wideby 1.25 in. 30 mm thick 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
12、fine abrasive finish on the planes perpendicular to theload and a fine saw finish on the other four planes. Thedimensions of the specimen 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
13、results is reported as the flexural strength of the stone.7.2 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, t
14、hethickness of the stone panels for the project has been estab-lished), it is often requested to perform flexure tests at the jobthickness. The following shall govern the specimen size where1This test method is under the jurisdiction of ASTM Committee C18 onDimension Stone and is the direct responsi
15、bility of Subcommittee C18.01 on TestMethods.Current edition approved April 1, 2009. Published April 2009. Originallyapproved in 1978. Last previous edition approved in 2006 as C 88006.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceast
16、m.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.it is requested to test at the job thickness and the job thic
17、knessis other than 1.25 in. 30 mm. The span as tested shall be 10times the thickness. The specimen lengths shall be not less than2 in. 50 mm and not more than 4 in. 100 mm greater thanthe span as tested. Where the thickness is less than 2.67 in.70 mm, the width of the specimen shall be 4 in. 100 mm.
18、Where the thickness is greater than 2.67 in. 70 mm the widthshall be 1.5 times the thickness. Where the thickness is otherthan 1.25 in. 30 mm and the specimen size is in accordancewith the job thickness criteria noted in the foregoing, theaverage value of the test results shall be reported as the fl
19、exuralstrength of the stone at the job thickness. All other require-ments shall be in accordance with 7.1.7.4 Where 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
20、 with the finish the same as on the job. The followingshall govern when it is requested to test at the job surfacefinish. 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
21、 of the specimen should be with the finished face inflexural tension. The average value of the test results shall 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 requiremen
22、ts of 7.3and 7.4, the average value of the test results shall be reportedas the flexural strength of the stone at 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 geometr
23、y may give useful results in terms ofa modulus of rupture value.8. Conditioning8.1 Before testing the specimens 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, continu
24、e to dry thespecimens until there are three successive hourly readings withthe same weight. After removing the specimens 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
25、 2C. Testthem immediately upon removal from the bath, wiping thespecimens free of surface water.9. Procedure9.1 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 6
26、00 psi/min4 MPa to failure.10. Calculation10.1 Calculate the flexural strength, s as follows:s53WL4bd2(1)where:s = 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 incl
27、ude the following:11.1.1 Stone type.11.1.2 Sizes of the specimens used.11.1.3 Preconditioning procedure used.11.1.4 Individual test results for each specimen.11.1.5 Average value of the test results for each group usingthe following relation:s5sum of observed valuesnumber of tests11.1.6 Standard dev
28、iation, s, of the test results for eachgroup using the following relation:s 5sum of observed value 2 s!2number of tests2111.1.7 Any variations from the above procedural tech-niques.11.2 The following additional information shall also bereported: identification of the sample, including name andNOTEAp
29、paratus may be used inverted.FIG. 1 Diagrammatic View of a Suitable Apparatus for Flexure Test of StoneC 880/C 880M 092location 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
30、 product may result indeviation from accepted values. A precision section will beadded when sufficient data are available to indicate acceptabletolerances in repeatability and reproducibility.13. Keywords13.1 dimension stone; flexural strength; flexure; stone; testASTM International takes no positio
31、n respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users 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.
32、This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM I
33、nternational Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address sho
34、wn below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 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).C 880/C 880M 093
