1、Designation: C 1144 89 (Reapproved 2004)Standard Test Method forSplitting Tensile Strength for Brittle Nuclear Waste Forms1This standard is issued under the fixed designation C 1144; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is used to measure the static splittingtensile strength of cylindrical specimens of brit
3、tle nuclearwaste forms. It provides splitting tensile-strength data that canbe used to compare the strength of waste forms when tests aredone on one size of specimen.1.2 The test method is applicable to glass, ceramic, andconcrete waste forms that are sufficiently homogeneous (Note1) but not to coat
4、ed-particle, metal-matrix, bituminous, orplastic waste forms, or concretes with large-scale heterogene-ities. Cementitious waste forms with heterogeneities 1 to 2mm and 60 HRC are required. Any permanent indentation of thebearing block invalidates the test. Suitable materials are toolsteels hardened
5、 from 60 to 65 HRC by conventional heattreatments and ground to obtain a smooth loading surface. Thesurfaces of the bearing blocks in contact with the pads shall beflat to within 60.03 mm, parallel within 60.03 mm/mm (1.7)measured on each of two perpendicular directions, and perpen-dicular to the lo
6、ading axis within 60.03 mm/mm (1.7).6.4 Pad MaterialsThe choice of pad material depends onthe strength and elastic modulus of the material tested. Asuitable pad material is one that prevents contact between thetest specimen and the bearing blocks but is soft enough todistribute the load over a small
7、 area. If the specimen andbearing block contact during the test (determined by visualinspection of the pad after testing), the test result is invalid. Ingeneral, balsa wood is a suitable pad material for testing glassand other materials with splitting tensile strengths less thanapproximately 100 MPa
8、. The grain of the wood shall bealigned perpendicular to the line of contact between specimenand bearing block with the grain parallel to the bearing block.The thickness of the balsa wood shall be 1.6 6 0.2 mm (Note3). Fully annealed OFHC copper foil 0.13 by 0.01-mm thick(Note 3) is suitable for hig
9、her strength waste forms.NOTE 3Deviations in pad material sizes of this magnitude will notaffect test results.6.5 Load-Measurement SystemUse a strip-chart or x-yrecorder to obtain a record of the loading force versus time.The recorder must be capable of responding to sudden changesin load (response
10、time 1 mm.Uncharacteristic minor chips or surface flaws (6 mm away from the loading points andonly if fracture does not initiate at these locations. If fractureoccurs at these locations, discard the results and repeat the test.Flaws as large as 1 mm are permitted on the flat surfaces onlyif they are
11、 at least 4 mm from the vertical diameter. Only flawssmaller than 0.1 mm are permitted within 4 mm of the verticaldiameter.9. Calibration and Standardization9.1 To ensure accuracy of stress calculations, the calibrationof the load-measurement system and specimen dimensionsmust be traceable to NIST s
12、tandards. Enter and maintainrecords of calibrations and dates of calibrations in laboratorynotebooks. A summary of applicable references is given inTable 2.10. Procedure10.1 Quality Assurance Requirements This proceduremust conform to all applicable quality assurance requirementsof the laboratory pe
13、rforming the test.10.2 Testing an Individual Specimen:10.2.1 Record the room temperature.10.2.2 Record the specimen thickness and diameter to thenearest 0.01 mm and verify that each specimen is withinspecified dimensional tolerances (Section 8). Examine speci-men surface for flaws or chips 0.1 mm.10
14、.2.3 Verify that bearing blocks are properly aligned (see6.3).10.2.4 Check load-measurement system with standardweights or an electrical method before testing using PracticeE 4. Choose the full-scale load indication of the recorder sothat the fracture load is indicated at a position that is 20 % off
15、ull scale.10.2.5 Position new pads for each test between the specimenand bearing blocks. Position the specimen on the lower padwith the flat surfaces parallel to the load axis. If flaws or chipsexist, position the specimens accordingly (see Section 8).Apply a light load (0.1 mm.11.3.2 Test Condition
16、sTabulate the dates of tests. Identifytest material, test temperature, pad material, and the rationalefor its selection, test machine, and crosshead speed (mm/s).11.3.3 CalibrationDocument the date and procedure forcalibrations of the load cell, load-measurement system, andcaliper micrometer. Descri
17、be procedures used to determine thatspecimens and bearing blocks conformed to specified toler-ances, flatness, and parallelisms.11.4 Fracture Strength Data:11.4.1 Test Specimen ResultsTabulate thickness and di-ameter (mm) for each specimen, fracture load ( N) for each test,and calculate fracture str
18、ength (MPa) for each test. Reportaverage strength, standard deviation, and relative standarddeviation for results of five or more tests.11.5 Description of Fracture:11.5.1 Describe the fracture for each specimen. If thefracture is similar in all specimens, one photograph of 33610 % magnification is
19、adequate; otherwise, include a photo-graph of each fracture type.11.5.2 Report whether the pads between the specimen andbearing blocks prevented contact of specimen and bearingblock.12. Precision and Bias12.1 No between-laboratory precision data are available.Based on available within-laboratory res
20、ults, the relative stan-dard deviation of the sample mean of the splitting tensilestrength is expected to be less than the maximum allowable(Table 1) for most waste forms.12.2 No data on bias are available; no standards are knownto exist for splitting tensile strength.ASTM International takes no pos
21、ition 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 responsibil
22、ity.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 AS
23、TM International 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
24、 shown 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 1144 89 (2004)5
