1、Designation: D 71 94 (Reapproved 2004)An American National StandardStandard Test Method forRelative Density of Solid Pitch and Asphalt (DisplacementMethod)1This standard is issued under the fixed designation D 71; the number immediately following the designation indicates the year of originaladoptio
2、n or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Sc
3、ope1.1 This test method covers the determination of relativedensity by water displacement of hard pitches and asphaltswith softening points above 70C.1.2 The relative density of hard pitch and asphalt shall bedetermined, whenever possible, on homogeneous natural frag-ments free of cracks. The use of
4、 cast cubes is not recommendeddue to the difficulty of avoiding incorporation of air bubbles.1.3 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 prac
5、tices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D61 Test Method for Softening Point of Pitches (Cube-in-Water Method)D 140 Practice for Sampling Bituminous MaterialsD 4296 Practice for Sampling Pitch3. Terminology3.1 Definition
6、:3.1.1 relative densitythe ratio of a given volume ofmaterial at 25C to the weight of an equal volume of water atthe same temperature (specific gravity).4. Summary of Test Method4.1 The sample is suspended from a thin wire and weighed,first in air, then submerged in water at 25.0C. The relativedensi
7、ty is calculated from these weights.5. Significance and Use5.1 This test method is useful in characterizing pitches andasphalts as one element in establishing uniformity of shipmentsand sources of supply.6. Apparatus6.1 Pan Straddle, suitable for use with an analytical bal-ance.6.2 Analytical Balanc
8、e, equipped with a hook above the panand capable of weighing a 20-g specimen to 1 mg.6.3 Water Bath, maintained at 25.0 6 0.2C and providedwith mechanical stirring/circulation.6.4 Thermometer, capable of measuring water temperatureof 25.0 6 0.2C (or other suitable temperature measuringinstrument).6.
9、5 Nichrome Wire, 0.127-mm (5-mL) diameter ormonofilament nylon fishing line of about the same diameter forattaching specimen to the balance pan hook.7. Bulk Sampling7.1 Samples from shipments shall be taken in accordancewith Practice D 140 or D 4296, and shall be free of foreignsubstances. Thoroughl
10、y mix the sample before removing arepresentative portion for the determination.8. Test Specimens8.1 Select two fragments of the bulk sample weighingbetween 5 and 20 g each. Inspect the fragments carefully toensure the use of specimens free of cracks and other surfacedefects.8.2 If the nature of the
11、material is such that specimens canbe cast without incorporation of air bubbles, follow thepreparation and casting directions in Test Method D61. Cubemolds measuring a minimum of 12.7 mm (12 in.) per side orlarger can be used.Assemble the cube molds so that solid cubeswith no perforations can be cas
12、t. A softening point cube moldbase plate can be inverted to provide the required flat surfaceon which to assemble the cube mold before pouring.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.05
13、on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved Nov. 1, 2004. Published November 2004. Originallyapproved in 1920. Last previous edition approved in 1999 as D 71 94 (1999).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custome
14、r Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.9. Procedure9.1 Tare the balance with
15、a piece of 0.127-mm (5-mL)Nichrome wire or monofilament nylon line sufficiently long toreach from the hook on the pan support to the straddle when thelatter is in position across the pan. Attach the test specimen tothe wire or line so that it is suspended 20 to 30 mm above thestraddle when the other
16、 end of the wire is attached to the hook.9.2 Weigh the suspended specimen to the nearest 1 mg andrecord this weight as a. Fill a 400 or 600-mL beaker two-thirdsfull with freshly boiled distilled water containing a smallamount of detergent (Note 1). Adjust the temperature of thewater to 25.0 6 0.2C,
17、and maintain this temperature duringthe remainder of the test. Place the beaker with water on thestraddle with the specimen, still suspended, fully submerged.When positioned correctly the beaker should not interfere withthe movement of the balance. Remove any air bubbles adher-ing to the specimen or
18、 wire by means of a thin wire, then weighthe immersed specimen to the nearest 1 mg. Record this weightas b.NOTE 1About 100 mg of Alconox3to 200 mL of water has beenfound satisfactory.9.3 Repeat the determination with the second test specimen.10. Calculation10.1 Calculate the relative density of the
19、material under testas follows:Relative Density at 25C 5 a/a 2 b! (1)where:a = weight of the specimen in air, mg, andb = weight of the specimen in water at 25.0C, mg.11. Report11.1 Report the average of the two determinations to thethird decimal place, unless the individual values differ by morethan
20、0.005. In this case, repeat the determinations with twonewly selected fragments or cast specimens. Discard the lowestof the four values and report the average of the others to thethird decimal place as relative density 25C/25C.12. Precision12.1 The following criteria shall be used for the acceptabil
21、-ity of results (95 % probability):12.1.1 RepeatabilityDuplicate values by the same opera-tor shall not be considered suspect unless they differ by morethan 0.005.12.1.2 ReproducibilityThe values reported by each of twolaboratories, representing the arithmetic average of duplicatedeterminations, sha
22、ll not be considered suspect unless thereported values differ by more than 0.007.13. Keywords13.1 asphalt; density; pitch; specific gravity; waterdisplacementASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standa
23、rd. 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 standard is subject to revision at any time by the responsible technical committee and must be reviewe
24、d 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 International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible
25、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.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consh
26、ohocken, 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).3The sole source of sup
27、ply of the apparatus known to the committee at this timeis Alconox, Inc, 30 Glenn St., Suite 309, White Plains, NY 10603. If you are awareof alternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee1, which you may attend.D 71 94 (2004)2
