1、Designation: C 458 98 (Reapproved 2006)Standard Test Method forOrganic Fiber Content of Asbestos-Cement Products1This standard is issued under the fixed designation C 458; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 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 covers the determination of the organicfiber content of asbestos-cement products.1.2 The values sta
3、ted in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 WarningBreathing of asbestos dust is hazardous.Asbestos and asbestos products present demonstrated healthrisks for users and for those with whom they come into contact.In addition to other
4、precautions, when working with asbestos-cement products, minimize the dust that results. For informa-tion on the safe use of chrysotile asbestos, refer to “Safe Use ofChrysotile: A Manual on Preventive and Control Measures.”21.4 This standard does not purport to address all of thesafety concerns, if
5、 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:3C114 Test Methods for Chemical Analysis of Hydr
6、aulicCementD 2946 Terminology for Asbestos and AsbestosCementProductsE11 Specification for Wire Cloth and Sieves for TestingPurposesE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated Materials2.2 BNQ Standard:4P2639-230 Asbestos-Cement
7、 Sheets: Methods of Test andControl3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 organic fiber contentthe percentage of organic mat-ter expressed as the equivalent percentage of cellulose in adried sample.3.1.2 For additional definitions refer to TerminologyD 2946.4. Apparat
8、us4.1 SieveA150-m (No. 100) sieve, conforming to Speci-fication E11.4.2 Drying Oven, ventilated, capable of being maintained at100 to 105C (212 to 220F).4.3 Apparatus for Determination of Total Carbon by DirectCombustionApparatus No. 1 of Practices E50.5. Reagent5.1 Hydrochloric Acid (1 + 17)Dilute
9、1 part by volume ofconcentrated hydrochloric acid (HCl, sp gr 1.19) with 17 partsof water.6. Procedure6.1 Grind a 100 6 10-g sample of the asbestos-cement topass a 150-m (No. 100) sieve.Avoid excessive, or high energygrinding that may cause partial thermal decomposition oforganic matter. Dry1goftheg
10、round sample to constant massin a ventilated oven at a temperature of 212 or 220F (100 to104.4C) and cool to room temperature in a desiccator.Determine the mass of the dried sample to the nearest 0.001 g.(WarningSee 1.3.)6.2 Transfer the dried sample to a 100-cm3beaker, add 50cm3of HCl (1 + 17), and
11、 digest on a steam bath for 20 min.After this treatment, filter the sample on a washed and ignitedGooch crucible pad and dry at a temperature of 100 to 105C(212 to 220F).6.3 Transfer the sample and crucible pad to a combustionboat and burn in a current of oxygen in a combustion furnace.Absorb the re
12、sultant carbon dioxide (CO2) by the proceduredescribed in 9.3.3 and 9.3.4 of BNQ Methods P2639-230.1This test method is under the jurisdiction of ASTM Committee C17 onFiber-Reinforced Cement Products and is the direct responsibility of SubcommitteeC17.03 on Asbestos-Cement Sheet Products and Accesso
13、ries.Current edition approved June 1, 2006. Published June 2006. Originallyapproved in 1960. Last previous edition approved in 2002 as C 458 98 (2002)e1.2Available from The Asbestos Institute, http:/ referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
14、serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from Bureau de Normalisation du Qubec, Dpartment of Industryand Commerce, 50 St-Joseph Street East, Qubec, QC, Canada G1K 3A5.1Copyright ASTM International
15、, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Make a blank determination, following the same procedure andusing the same amounts of all materials except the sample.7. Calculation7.1 Calculate the organic fiber content, in mass percent, asfollows (Note 1):Organ
16、ic fiber cellulose!,%5 A 2 B! 3 0.614/C 3 100where:A = mass of CO2,g,B = correction for CO2in blank, g,C = mass of dry sample, g, and0.614 = gravimetric factor (C6H10O5/6CO2) for convertingCO2absorbed to cellulose.NOTE 1Asbestos-cement products may include water-repellent sub-stances that would prod
17、uce CO2in this test method for organic fiber. Suchwater-repellent substances are usually soluble in chloroform. In case ofdispute, the chloroform-soluble organic substance shall be determined asdescribed in Sections 69 to 72 of Test Methods C114. A40.0-g sample ofthe ground, oven-dried material shal
18、l be used for this test method.Water-repellent substances contain a higher percentage of carbon thancellulose. To correct for this, 1.8 times the percentage of chloroform-soluble organic substance, so determined, shall be subtracted from thecalculated percentage of organic fiber (cellulose).NOTE 2Th
19、is test method does not provide a correction for organicpigments, which would likewise produce CO2in this test method fororganic fiber.8. Precision and Bias8.1 RepeatabilityThe intra-laboratory single apparatus,operator and specimen repeatability of the mass of organicfiber content determined is as
20、follows:Concentration Mean, gStandardDeviation, gRelative StandardDeviation, %LowHigh0.005710.062020.000810.0014915.92.48.2 BiasBias has not yet been established in accordancewith the requirements of ASTM.9. Keywords9.1 asbestos; asbestos-cement; organic fiberASTM International takes no position res
21、pecting 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.This
22、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 Intern
23、ational 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 shown be
24、low.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 458 98 (2006)2
