1、Designation: C 1096 07Standard 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 of last revision. A n
2、umber 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 cellu-lose content of asbestos-cement products. Refer to Note 1 andNote 2.1.2 Before t
3、his 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 organic substances inquestion present in samples of asbestos-cement.1.3 The values stat
4、ed 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 healthrisks for users and for those with whom they come into contact.In addition to other p
5、recautions, 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 and ControlMeasures.”21.5 This standard does not purport to address all of thesafety conc
6、erns, 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. See 1.4 for aspecific safety warning.2. Referenced Documents2.1 ASTM Standards:3C
7、114 Test Methods for Chemical Analysis of HydraulicCementD 1193 Specification for Reagent WaterE11 Specification for Wire Cloth and Sieves for TestingPurposes2.2 ACS Standard:Reagent Chemicals, American Chemical Society Specifica-tions43. Significance and Use3.1 The determination of wood fiber in as
8、bestos-cementproducts is necessary because such fibers may be added whenmulti-wall paper bags containing the asbestos 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 usuallyh
9、ave a negligible effect on product durability and performance,higher concentrations can have deleterious effects on productsexposed to moisture and thermal shocks.4. Interferences4.1 The presence of organic compounds such as surface-active processing aids and water-repellent substances thatwould pro
10、duce CO2during the digestion steps of the procedurewould probably affect results. Refer to Note 1.4.2 The presence of 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 Spe
11、ci-fication E11.5.2 Drying oven, ventilated, capable of maintaining 100 to105C (212 to 220F).5.3 Apparatus for determination of total carbon by directcombustion. The several types of commercially availableapparatus are generally suitable. A typical combustion trainmay include the following sequence
12、of components:5.3.1 Source of oxygen under pressure,5.3.2 Pressure reducing valve,5.3.3 Rubber tubing,5.3.4 Scrubber for removing traces of carbon dioxide andmoisture in the oxygen,5.3.5 Manometer,5.3.6 Combustion tube,5.3.7 Electric furnace,1This test method is under the jurisdiction of ASTM Commit
13、tee C17 onFiber-Reinforced Cement Products and is the direct responsibility of SubcommitteeC17.03 on Asbestos - Cement Sheet Products and Accessories.Current edition approved Nov. 1, 2007. Published December 2007. Originallyapproved in 1988. Last previous edition approved in 2004 as C 1096 91 (2004)
14、e1.2Available from The Asbestos Institute, http:/ referenced ASTM standards, visit the 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
15、American Chemical Society, 1155 16th St., NW, Washington,DC.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.3.8 Filter packed with absorbent cotton for the removal ofsolid particles,5.3.9 U-tube containing anhydrous Mg (ClO4)2,5.3.
16、10 Absorbing bulb containing 20 to 30 mesh inert baseimpregnated with NaOH absorbing the CC, and5.3.11 Bottle containing 112SO4(sp. gr 1.84) to protect thedischarge end.6. Reagents6.1 Type III Reagent water conforming to SpecificationD 1193.6.2 Hydrochloric AcidDilute one part of concentratedhydroch
17、loric acid (HCl, sp gr 1.19 conforming to the ACSspecifications) with 17 parts of reagent water.6.3 Chromic AcidFor each digestion dissolve 30 g ofchromium trioxide crystals conforming to the ACS specifica-tions (see 2.2) with 60 cm3of reagent water.7. Hazards7.1 Warningsee 1.4.8. Sampling, Test Spe
18、cimens, 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 expected in the product underanalysis. If no estimate of the wood fiber concentration isavailable take a 3-g sample. If the inorganic
19、 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 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
20、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 absorptionsystem.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
21、 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 water.9.6 Slowly heat the digestion flask to boiling and maintainboiling for 30 min.9.7 Obtain the total mass of carbon dioxide evolv
22、ed byreweighing the carbon dioxide absorption tube and subtractingthe initial mass determined in 9.2.9.8 Determine the evolved carbon dioxide of inorganicorigin (present as carbonates) by repeating steps 9.1-9.7 usingthe hydrochloric acid with the second specimen.NOTE 1Asbestos-cement products may i
23、nclude surface-active pro-cessing aids and water-repellent substances that would produce carbondioxide during the chromic acid digestion step of this test method. Suchsubstances are usually soluble in chloroform. In case of dispute, thechloroform-soluble organic substance shall be determined as desc
24、ribed inSections 69 to 72 of Test Methods C114. A 40.0-g sample of thepulverized, oven-dried material shall be used for this correction procedure.Water-repellent substances contain a higher percentage of carbon thancellulose. To correct for this, 1.8 times the percentage of chloroform-soluble organi
25、c substance, so determined, shall be subtracted from thecalculated percentage of wood fiber.NOTE 2This test method does not provide a correction for organicpigments or polymeric fibers that decompose during chromic aciddigestion and which could produce carbon dioxide and thereby interferewith the re
26、sults 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-tained in 9.7, and the carbon dioxide evolved from inorganiccarbonates as obtained in 9.8.10.2 Calculate the carbon that corresponds t
27、o 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 the as-receivedbasis by dividing the percentage carbon evolved as obtained in10.2 by the percent carbon in the wood. If that value is n
28、otknown, 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 dividingthe concentration of the wood on the as-received basis asobtained in 10.3 by100 2 A 2 B! % (1)where:A = Percent CO2originating f
29、rom the hydration reaction(carbonation) of the cement and calculated from theresults obtained with a blank sample prepared similarlyand containing no wood. Alternatively, 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
30、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 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 o
31、f 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 absorption 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
32、 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 carbon dioxide evolved from wood is:C109607210.5.2.1 Carbon dioxide evolved from inorganiccarbonates = WaW3= 249.0643g 249.0236g = 0.040
33、7g(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 inorganic 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 inorg
34、aniccarbonates (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 %.10.5.3 The carbon that corresponds 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 1
35、0.5.1.7 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) = 8.7/(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
36、 = 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 percent of wood fiberin the dry furnish determined is as follows:Mean, % = 9.6 %,Standard Deviation, % = 0.082 %,Relative standard deviation, %
37、= 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; asbestos-cement; cellulose; cellulose fibercontent; determination; wood; wood fiber contentASTM International takes no position respecting the valid
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