1、Designation: D71 94 (Reapproved 2015)1Standard Test Method forRelative Density of Solid Pitch and Asphalt (DisplacementMethod)1This standard is issued under the fixed designation D71; the number immediately following the designation indicates the year of originaladoption or, in the case of revision,
2、 the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1NOTESI unit formatting was cor
3、rected editorially in May 2015.1. Scope1.1 This test method covers the determination of relativedensity by water displacement of hard pitches and asphaltswith softening points above 70 C.1.2 The relative density of hard pitch and asphalt shall bedetermined, whenever possible, on homogeneous natural
4、frag-ments free of cracks. The use of cast cubes is not recommendeddue to the difficulty of avoiding incorporation of air bubbles.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address
5、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 use.2. Referenced Documents2.1 ASTM Standards:2D61 Test Method fo
6、r Softening Point of Pitches (Cube-in-Water Method)D140 Practice for Sampling Bituminous MaterialsD4296 Practice for Sampling Pitch3. Terminology3.1 Definitions:3.1.1 relative densitythe ratio of a given volume ofmaterial at 25 C to the mass of an equal volume of water at thesame temperature (specif
7、ic 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 25.0 C. The relativedensity is calculated from these masses.5. Significance and Use5.1 This test method is useful in characterizing pitches andasphalts as one elemen
8、t in establishing uniformity of shipmentsand sources of supply.6. Apparatus6.1 Pan Straddle, suitable for use with an analytical bal-ance.6.2 Analytical Balance, 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 C 6 0.2 C and pro-vid
9、ed with mechanical stirring/circulation.6.4 Thermometer, capable of measuring water temperatureof 25.0 C 6 0.2 C (or other suitable temperature measuringinstrument).6.5 Nichrome Wire, 0.127 mm diameter or monofilamentnylon fishing line of about the same diameter for attachingspecimen to the balance
10、pan hook.7. Bulk Sampling7.1 Samples from shipments shall be taken in accordancewith Practice D140 or Practice D4296, and shall be free offoreign substances. Thoroughly mix the sample before remov-ing a representative portion for the determination.8. Test Specimens8.1 Select two fragments of the bul
11、k sample weighingbetween 5 g 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 material is such that specimens canbe cast without incorporation of air bubbles, follow the1This test method is under the jurisdi
12、ction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved April 1, 2015. Published May 2015. Originallyapproved in 1920. Last previous editi
13、on approved in 2009 as D71 94(2009). DOI:10.1520/D0071-94R15E01.2For 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 websi
14、te.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1preparation and casting directions in Test Method D61. Cubemolds measuring a minimum of 12.7 mm per side or larger canbe used. Assemble the cube molds so that solid cubes with noperfo
15、rations can be cast. A softening point cube mold baseplate can be inverted to provide the required flat surface onwhich to assemble the cube mold before pouring.9. Procedure9.1 Tare the balance with a piece of 0.127 mm Nichromewire or monofilament nylon line sufficiently long to reach fromthe hook o
16、n the pan support to the straddle when the latter is inposition across the pan. Attach the test specimen to the wire orline so that it is suspended 20 mm to 30 mm above the straddlewhen the other end of the wire is attached to the hook.9.2 Weigh the suspended specimen to the nearest 1 mg andrecord t
17、his mass as a. Fill a 400 mL or 600 mL beakertwo-thirds full with freshly boiled distilled water containing asmall amount of detergent (Note 1). Adjust the temperature ofthe water to 25.0 C 6 0.2 C, and maintain this temperatureduring the remainder of the test. Place the beaker with water onthe stra
18、ddle with the specimen, still suspended, fully sub-merged. When positioned correctly the beaker should notinterfere with the movement of the balance. Remove any airbubbles adhering to the specimen or wire by means of a thinwire, then weigh the immersed specimen to the nearest 1 mg.Record this mass a
19、s 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 material under testas follows:Relative Density at 25 C 5 a/a 2 b! (1)where:a = mass of the specimen in
20、air, mg, andb = mass of the specimen in water at 25.0 C, mg.11. Report11.1 Report the average of the two determinations to thethird decimal place, unless the individual values differ by morethan 0.005. In this case, repeat the determinations with twonewly selected fragments or cast specimens. Discar
21、d the lowestof the four values and report the average of the others to thethird decimal place as relative density 25 C 25 C.12. Precision12.1 The following criteria shall be used for the acceptabil-ity of results (95 % probability):12.1.1 RepeatabilityDuplicate values by the same opera-tor shall not
22、 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, shall not be considered suspect unless thereported values differ by more than 0.007.13. Keywords13.1 aspha
23、lt; density; pitch; specific gravity; water displace-mentASTM 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 the validity of any such paten
24、t 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 reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited eithe
25、r 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 technical committee, which you may attend. If you feel that your comments have not received a fair he
26、aring 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 standar
27、d 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 Copyright Clearance Center, 222Rosewood Drive, Dan
28、vers, MA 01923, Tel: (978) 646-2600; http:/ sole source of supply 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 committee,1which you may attend.D71 94 (2015)12
