1、Designation: C458/C458M 98 (Reapproved 2011)1Standard Test Method forOrganic Fiber Content of Asbestos-Cement Products1This standard is issued under the fixed designation C458/C458M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision,
2、the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEUnits information was editorially corrected in January 2012.1. Scope1.1 This test method covers the determination
3、 of the organicfiber content of asbestos-cement products.1.2 The values stated in either SI units or inch-pound unitsare 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. Combiningvalue
4、s from the two systems may result in non-conformancewith the standard.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 precautions, when working with asbest
5、os-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 any, associated with its use. It is
6、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 HydraulicCementD2946 Terminology for Asbe
7、stos and AsbestosCementProductsE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated Materials2.2 BNQ Standard:4P2639-230 Asbestos-Cement Sheets: Methods of Test andControl3.
8、 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 Terminology D2946.4. Apparatus4.1 SieveA150-m (No. 100) sieve, co
9、nforming 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 1 part by volume ofconcentrated hydroch
10、loric 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. Dry1goftheground sample to constant massin a venti
11、lated 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 digest on a steam bath for 20 min.After
12、this treatment, filter the sample on a washed and ignitedGooch crucible pad and dry at a temperature of 100 to 105C212 to 220F.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 - Cem
13、ent Sheet Products and Accessories.Current edition approved Nov. 1, 2011. Published January 2012. Originallyapproved in 1960. Last previous edition approved in 2006 as C458 98 (2006).DOI: 10.1520/C0458_C0458M-98R11E01.2Available from The Asbestos Institute, http:/ referenced ASTM standards, visit th
14、e 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 page onthe ASTM website.4Available from Bureau de Normalisation du Qubec, Dpartment of Industryand Commerce, 50 St-Joseph Str
15、eet East, Qubec, QC, Canada G1K 3A5.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.3 Transfer the sample and crucible pad to a combustionboat and burn in a current of oxygen in a combustion furnace.Absorb the resultant carbon diox
16、ide (CO2) by the proceduredescribed in 9.3.3 and 9.3.4 of BNQ Methods P2639-230.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):Organic fib
17、er 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 produce CO
18、2in 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 shall be u
19、sed 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 2This tes
20、t 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 follow
21、s: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 respectin
22、g 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 standa
23、rd 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 Internationa
24、l 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 below.Th
25、is 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).C458/C458M 98 (2011)12
