ASTM C1096-1991(2004)e1 Standard Test Method for Determination of Wood Fiber in Asbestos Cement《石棉水泥中木纤维含量的测定方法》.pdf

1、Designation: C 1096 91 (Reapproved 2004)e1Standard Test Method forDetermination of Wood Fiber in Asbestos Cement1This standard is issued under the fixed designation C 1096; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o

2、f 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.e1NOTEAsbestos warning was moved from 7.1 to 1.4 in September 2004.1. Scope1.1 This test method covers the determination of the

3、 cellu-lose content of asbestos-cement products. Refer to Note 1 andNote 2.1.2 Before this test method can be used for the determina-tion of other organic substances in asbestos-cement, it must beascertained that accurate results can be obtained by correlationtrials with known concentrations of the

4、organic substances inquestion present in samples of asbestos-cement.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 WarningBreathing of asbestos dust is hazardous.Asbestos and asbestos products present demonstrated heal

5、thrisks for users and for those with whom they come into contact.In addition to other precautions, when working with asbestos-cement products, minimize the dust that results. For informa-tion on the safe use of chrysoltile asbestos, refer to “Safe Useof Chrysotile Asbestos: A Manual on Preventive an

6、d ControlMeasures.”21.5 This standard does not purport 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

7、 use. See 1.4 for aspecific safety warning.2. Referenced Documents2.1 ASTM Standards:3C 114 Test Methods for Chemical Analysis of HydraulicCementD 1193 Specification for Reagent WaterE 11 Specification for Wire Cloth Sieves for Testing Pur-posesE 50 Practices for Apparatus, Reagents, and Safety Prec

8、au-tions for Chemical Analysis of Metals2.2 ACS Standard:Reagent Chemicals, American Chemical Society Specifica-tions43. Significance and Use3.1 The determination of wood fiber in asbestos-cementproducts is necessary because such fibers may be added whenmulti-wall paper bags containing the asbestos

9、are included inthe batch formulations, or cellulose may be added as aprocessing aid during the manufacture of the products.3.2 Although moderate concentrations of wood fiber usuallyhave a negligible effect on product durability and performance,higher concentrations can have deleterious effects on pr

10、oductsexposed to moisture and thermal shocks.4. Interferences4.1 The presence of organic compounds such as surface-active processing aids and water-repellent substances thatwould produce CO2during the digestion steps of the procedurewould probably affect results. Refer to Note 1.4.2 The presence of

11、organic pigments and organic poly-meric fibers other than cellulose could also interfere and impairaccuracy (Note 2).5. Apparatus5.1 Sieve, a 149 m (No. 100), sieve conforming to Speci-fication E 11.5.2 Drying oven, ventilated, capable of maintaining 100 to105C (212 to 220F).5.3 Apparatus for determ

12、ination of total carbon by directcombustion. Apparatus No. 1 of Practices E 50.6. Reagents6.1 Type III Reagent water conforming to SpecificationD 1193.1This test method is under the jurisdiction of ASTM Committee C17 onFiber-Reinforced Cement Products and is the direct responsibility of Subcommittee

13、C17.03 on AsbestosCement Sheet Products and Accessories.Current edition approved June 2004. Published July 2004. Originally approved in1988. Last previous edition approved in 1999 as C 1096 91 (1999).2Available from The Asbestos Institute, http:/ referenced ASTM standards, visit the ASTM website, ww

14、w.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 American Chemical Society, 1155 16th St., NW, Washington,DC.1Copyright ASTM International, 100 Barr Har

15、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Hydrochloric AcidDilute one part of concentratedhydrochloric acid (HCl, sp gr 1.19 conforming to the ACSspecifications) with 17 parts of reagent water.6.3 Chromic Acid For each digestion dissolve 30 g ofchromium trioxide cry

16、stals conforming to the ACS specifica-tions (see 2.2) with 60 cm3of reagent water.7. Hazards7.1 Warning see 1.4.8. Sampling, Test Specimens, and Test Units8.1 For each replicate analysis desired take sufficient sampleto yield two specimens each with a mass of 0.15 g per unitpercentage of wood fiber

17、expected in the product underanalysis. If no estimate of the wood fiber concentration isavailable take a 3-g sample. If the inorganic carbonate contentis known to yield 1 % CO2or more when digested, a 1-gsample will suffice.8.2 Grind the sample to entirely pass the 149 m (No. 100)sieve (see 1.4).8.3

18、 Dry the sample to constant weight in the oven at 100 to105C (212 to 220F) and cool to room temperature in adesiccator.8.4 Weigh out two specimens to the nearest 0.001 g.9. Procedure9.1 Transfer one specimen to the digestion flask of theapparatus and connect this to the carbon dioxide absorptionsyst

19、em.9.2 Determine the mass of the carbon dioxide absorptiontube.9.3 Pour the chromic acid into the addition funnel.9.4 Apply vacuum to the absorption system and introducethe chromic acid slowly.9.5 When the acid is completely added, rinse the chromicacid from the funnel with small amounts of reagent

20、water.9.6 Slowly heat the digestion flask to boiling and maintainboiling for 30 min.9.7 Obtain the total mass of carbon dioxide evolved byreweighing the carbon dioxide absorption tube and subtractingthe initial mass determined in 9.2.9.8 Determine the evolved carbon dioxide of inorganicorigin (prese

21、nt as carbonates) by repeating steps 9.1-9.7 usingthe hydrochloric acid with the second specimen.NOTE 1Asbestos-cement products may include surface-active pro-cessing aids and water-repellent substances that would produce carbondioxide during the chromic acid digestion step of this test method. Such

22、substances are usually soluble in chloroform. In case of dispute, thechloroform-soluble organic substance shall be determined as described inSections 69 to 72 of Test Methods C 114. A 40.0-g sample of thepulverized, oven-dried material shall be used for this correction procedure.Water-repellent subs

23、tances 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 wood fiber.NOTE 2This test method does not provide a correction for organicpigments o

24、r polymeric fibers that decompose during chromic aciddigestion and which could produce carbon dioxide and thereby interferewith the results obtained by this test method.10. Calculation10.1 Calculate the carbon dioxide evolved from wood as thedifference between the total carbon dioxide evolved as ob-

25、tained in 9.7, and the carbon dioxide evolved from inorganiccarbonates as obtained in 9.8.10.2 Calculate the carbon that corresponds to the carbondioxide evolved from wood as obtained in 10.1 by multiplyingby the ratio of carbon to carbon dioxide = 12/44.10.3 Calculate the concentration of wood on t

26、he as-receivedbasis by dividing the percentage carbon evolved as obtained in10.2 by the percent carbon in the wood. If that value is notknown, assume the nominal value of 45.1 % carbon.10.4 Calculate the concentration of wood present in the dryfurnish (solid ingredients of the asbestos-cement) by di

27、vidingthe concentration of the wood on the as-received basis asobtained in 10.3 by100 2 A 2 B! % (1)where:A = Percent CO2originating from the hydration reaction(carbonation) of the cement and calculated from theresults obtained with a blank sample prepared similarlyand containing no wood. Alternativ

28、ely, use the arbi-trary value of 5.6 %.B = Percent CO2of inorganic origin obtained in 9.8.10.5 Sample Calculation:10.5.1 For the case where the following analytical resultswere obtained:10.5.1.1 Wa= 2.0602 g mass of specimen digested in thechromic acid.10.5.1.2 W1= 249.0113 g mass of absorption tube

29、 beforechromic acid digestion.10.5.1.3 W2= 249.3499 g mass of absorption tube afterchromic acid digestion.10.5.1.4 Wb= 1.9398 g mass of specimen digested in thehydrochloric acid.10.5.1.5 W3= 249.0236 g mass of absorption tube beforehydrochloric acid digestion.10.5.1.6 W4= 249.0643 g mass of absorpti

30、on tube afterhydrochloric acid digestion.10.5.1.7 Carbon content of wood assumed to be 45.1 %.10.5.1.8 Carbon dioxide originating from hydration of ce-ment; 5.6 % assumed. Total carbon dioxide evolved W2W1 = 249.3499 g 249.0113 g = 0.3386 g (W2W1)/Wa= 0.3386/2.0602 = 0.165 = 16.5 % CO2.10.5.2 The ca

31、rbon dioxide evolved from wood is:10.5.2.1 Carbon dioxide evolved from inorganiccarbonates = WaW3= 249.0643g 249.0236g = 0.0407g(W4W3)/Wb= 0.0407/1.9398 = 0.021 = 2.1 % CO2.10.5.2.2 Net value of carbon dioxide evolved fromwood = 16.5 2.1 = 14.4 % CO2.10.5.2.3 Carbon dioxide evolved from the inorgani

32、c carbon-ates (from 10.5.1.5 and 10.5.1.6)= 249.0643 249.0236 = 0.0407 g.10.5.2.4 Percentage carbon dioxide evolved from inorganiccarbonates (from 10.5.1.4) = 0.0407 3 100/1.9398 = 2.1 %.10.5.2.5 Carbon dioxide evolved from wood= 16.5 2.1 = 14.4 %.C 1096 91 (2004)e1210.5.3 The carbon that correspond

33、s to the carbon dioxideevolved from wood (from 10.5.2.5)= 14.4 % 3 12/44 = 3.9 %.10.5.4 The concentration of wood on the as-received basis(from 10.5.1.7 and 10.5.3) = 3.9 % 3 100/45.1 = 8.7 % (where45.1 denotes Cstdnominal).10.5.5 The concentration of wood present in the dry furnish(from 10.5.4) = 8

34、.7/(100 AB)%,where:A = 5.6 % (from 10.5.1.8), andB = 2.1 % (from 10.5.2.4).Therefore, the nominal concentration of wood present in thedry furnish = 8.7 3 100 (100 5.6 2.1) % = 9.5 %.11. Precision and Bias11.1 PrecisionThe intra-laboratory single apparatus, op-erator and specimen repeatability of the

35、 percent of wood fiberin the dry furnish determined is as follows:Mean, % = 9.6 %,Standard Deviation, % = 0.082 %,Relative standard deviation, % = 0.85 %.11.2 BiasResults obtained average 4.2 % lower than thetrue value of the wood fiber concentration in the dry furnish.12. Keywords12.1 asbestos; asb

36、estos-cement; cellulose; cellulose fibercontent; determination; wood; wood fiber contentASTM International takes no position 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

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39、nts have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address 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 1096 91 (2004)e13