ASTM D61-1975(2010) Standard Test Method for Softening Point of Pitches (Cube-in-Water Method)《硬沥青的软化点的标准试验方法(水中方块试验法)》.pdf

1、Designation: D61 75 (Reapproved 2010)Standard Test Method forSoftening Point of Pitches (Cube-in-Water Method)1This standard is issued under the fixed designation D61; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of las

2、t revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the soft-ening point of pitches below 176F (80C). Pitches of highersoftening poi

3、nt should be tested by Test Method D2319 or TestMethod D3104.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does n

4、ot 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 use.2. Referenced Documents2.1 ASTM Standar

5、ds:2D140 Practice for Sampling Bituminous MaterialsD2319 Test Method for Softening Point of Pitch (Cube-in-Air Method)D3104 Test Method for Softening Point of Pitches (MettlerSoftening Point Method)E1 Specification for ASTM Liquid-in-Glass Thermometers3. Summary of Test Method3.1 Two cubes of pitch,

6、 supported on wire hooks, are heatedat a controlled rate in water in a glass container. The softeningpoint is defined as the mean of the temperatures at which thecubes sag downwards a distance of 25 mm.4. Significance and Use4.1 Pitch does not go through a solid-liquid phase changewhen heated, and t

7、herefore it does not have a true meltingpoint. As the temperature rises, pitch softens and becomes lessviscous. The softening point is arbitrarily defined and shall beestablished by a closely controlled method which shall becarefully followed if test results are to be reproducible.4.2 This test is u

8、seful in determining the consistency ofpitch as one element in establishing the uniformity of ship-ments or sources of supply.5. Apparatus5.1 MoldA mold suitable for forming two12-in. (12.7-mm) cubes of pitch, having cylindrical core pins 12 gauge(2.05 mm) in diameter located in the base plate of th

9、e assemblyto produce accurately centered suspension holes in the cubes.(See Fig. 1.)5.2 HooksTwo L-shaped hooks, made of 12-gauge (2.05-mm) copper wire. The foot of the hook shall be 1-in. (25-mm)long and at a right angle to the upright portion for insertion intothe center hole of the pitch cube.5.3

10、 ContainerA glass vessel that can be heated, not lessthan 85 mm in diameter and 105 mm deep. (A standard600-mL low-form beaker meets these requirements).5.4 ThermometerAn ASTM Low Softening Point Ther-mometer having a range from 30 to 180F (2 to 80C) andconforming to the requirements for Thermometer

11、 15F (15C) asdescribed in Specification E1.5.5 Heat Source:5.5.1 Electric HeaterA hot plate or immersion heaterprovided with a variable transformer or other device suitablefor regulating the temperature of the heating element.5.5.2 Gas HeaterA bunsen-type burner, fitted with achimney.6. Sampling6.1

12、Samples from shipments shall be taken in accordancewith Practice D140 and shall be free of foreign substances.Thoroughly mix the sample before removing a representativeportion for the determination or for dehydration.6.2 If the presence of water is indicated by surface foam onheating, maintain the s

13、ample at a temperature of about 260F(125C) in an open container until the surface is free of foam.Take care not to overheat, and remove from the heat source assoon as the foam has subsided.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is th

14、e direct responsibility of SubcommitteeD02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved Feb. 15, 2010. Published March 2010. Originallyapproved in 1919. Last previous edition approved in 2004 as D6175(2004). DOI:10.1520/D0061-75R10.2For referenced ASTM stand

15、ards, 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, P

16、A 19428-2959, United States.7. Test Specimens7.1 Coat the inner surfaces and core pins of the mold verylightly with silicone oil or silicone grease. Form the pitch intotruly shaped cubes either by pressing (7.2) or by pouring (7.4),the latter being preceded by melting (7.3) if the sample is solid.Us

17、e an excess of pitch in either case. Cool until firm andremove the surplus material by drawing the heated blade of aputty knife or spatula across the surface of the mold so that thecubes are pressed into the cavities. Then open the mold andremove the cubes carefully to avoid distortion. Inspect each

18、specimen for possible cracks or bubbles and reject any whichare not perfect.7.2 Pitches with softening points up to about 140F (60C)can usually be pressed into the mold by hand at, or slightlyabove, room temperature. If too soft, they may be pressedunder water at about 40F (5C).7.3 To melt a dry pit

19、ch sample, add the material to acontainer having a height equal to or exceeding its width anda volume of not less than 50 mL, until it is about half full. Placethe container on a hot plate, or in an oven or bath. Do not usean open flame for melting pitch. After melting is complete, stirgently but th

20、oroughly, avoiding the incorporation of airbubbles. The maximum temperature should not exceed theexpected softening point by more than 90F (50C). Any foamthat forms shall be skimmed off.7.4 Pour a slight excess of the liquid pitch into the moldwith the lip of the container close to the surface so as

21、 tominimize the entrainment of air bubbles. Underpouring pastFIG. 1 Apparatus for Cube-in-Water MethodD61 75 (2010)2the blade of a spatula is helpful in this respect. Even smallbubbles markedly affect the weight of the cube and theobserved softening point. Cool the specimens in the mold untilfirm, u

22、nder cold water if necessary; then trim and inspect thecubes as directed in 7.1.8. Procedure8.1 Pitches Having Softening Points Between 110 and176F (43 and 80C):8.1.1 Assemble the apparatus as shown in Fig. 1. Fill thecontainer to a depth of about 100 mm with freshly boileddistilled water cooled to

23、60F (15C) (Notes 1 and 2). Placetwo cubes of pitch on hooks as shown in Fig. 1, warming thehooks slightly before inserting them in the center holes ifnecessary. Suspend the specimens in the bath so that the loweredges are 1 in. (25 mm) above the bottom of the container.Position the thermometer so th

24、at the bulb is between the cubesand within 6 mm, but not touching either cube. The bottom ofthe bulb should be level with the bottom of the cubes. Allowthe specimens to remain in the bath at 60F (15C) for 15 minbefore applying heat.NOTE 1The use of freshly boiled water is essential to prevent thefor

25、mation of air bubbles on its surface which may retard the sinking of thecube.NOTE 2A sheet of filter paper that will sink when wet may be placedon the bottom of the container to prevent the pitch from sticking to theglass.8.1.2 Apply heat in such a manner that the temperature ofthe water is raised 9

26、F (5C)/min. The rate shall be uniformand shall not be averaged over the period of the test. Themaximum permissible variation for any 1-min period, after thefirst three, shall be 61F (0.5C). Reject all tests in which therate of rise is outside these limits.8.1.3 The softening point is the average of

27、the temperaturesat which the two cubes touch the bottom of the container.Estimate individual readings to the nearest 0.5F (0.2C).Repeat the determination if the individual values differ by morethan 2F (1C).8.2 Pitches Having Softening Points Below 110F (43C)Follow the procedures described in 8.1, bu

28、t cool the water bathto 40F (5C). After immersing the specimens in the bath,maintain the temperature for at least 15 min before applyingheat.9. Report9.1 Report the average value found in 8.1.3, rounded to thenearest 1F (0.5C) as the softening point (cube-in-water).10. Precision and Bias10.1 The fol

29、lowing criteria shall be used for judging theacceptability of the results (95 % confidence level):10.1.1 RepeatabilityDuplicate values by the same opera-tor shall not be considered suspect unless they differ by morethan 3F (1.5C).10.1.2 ReproducibilityThe values reported by each of twolaboratories s

30、hall not be considered suspect unless they differby more than 5F (3C).10.1.3 BiasThe procedure in Test Method D61 for soft-ening point has no bias because the value of softening point isdefined only in the terms of this test method.11. Keywords11.1 cube-in-water; pitch; softening pointASTM Internati

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34、s, 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D61 75 (2010)3