1、Designation: D3461 14D3461 18Standard Test Method forSoftening Point of Asphalt and Pitch (Mettler Cup-and-BallMethod)1This standard is issued under the fixed designation D3461; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of the softening point of asphalt and pitch in the range from 50 C t
3、o 180 C bythe cup-and-ball apparatus, and gives results comparable to those obtained by Test Method D36.NOTE 1If the softening point of asphalt by this Mettler cup-and-ball method fails to meet specified requirements, tests may be rerun using the TestMethod D36 (ring-and-ball) softening point appara
4、tus as a referee method.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of
5、regulatory limitations prior to use.1.3 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade O
6、rganization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A314 Specification for Stainless Steel Billets and Bars for ForgingD36 Test Method for Softening Point of Bitumen (Ring-and-Ball Apparatus)D140 Practice for Sampling Asphalt MaterialsD4296 Practice for
7、 Sampling Pitch3. Summary of Test Method3.1 In this test method the softening point is defined as the temperature at which the specimen, suspended in a cylindrical cupwith a 6.5 mm hole in the bottom and with a lead ball, 8 mm in diameter, centered on top of the sample in the cup, flows downwarda di
8、stance of 19 mm to interrupt a light beam, as the sample is heated at a linear rate in air.4. Significance and Use4.1 Asphalt and pitch do not go through a solid-liquid phase change when heated, and therefore do not have true melting points.As the temperature is raised, they gradually soften or beco
9、me less viscous. For this reason, the determination of the softening pointmust be made by an arbitrary, but closely defined, method if the test values are to be reproducible.4.2 This test method is useful in determining the consistency as one element in establishing the uniformity of shipments orsou
10、rces of supply.5. Apparatus5.1 A METTLER TOLEDO dropping point cell3 can be used to determine softening points by this test method. Thesecommercially available instruments consist of a control unit with a digital temperature indicator with furnace built in or attached,1 This test method is under the
11、 jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved Oct. 1, 2014Dec. 1, 2018. Published November 2014January 2019. Originally
12、approved in 1976. Last previous edition approved in 20122014as D3461 97D3461 14. (2012). DOI: 10.1520/D3461-14.10.1520/D3461-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information
13、, refer to the standards Document Summary page on the ASTM website.3 The sole source of supply of the apparatus known to the committee at this time is available from Mettler-Toledo, LLC., 1900 Polaris Pkwy, Columbus, OH 43240,. If you are aware of alternative suppliers, please provide this informati
14、on toASTM International Headquarters.Your comments will receive careful considerationat a meeting of the responsible technical committee,1 which you may attend.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been m
15、ade to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A
16、 Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1sample cartridges, and accessories. The control unit automatically regulates the heating rate of the furnace. The softening
17、 point isindicated on the readout, and the heating program stopped, when the sample flow triggers the softening point detection. A generalview of the components of the METTLER TOLEDO softening point instrument is shown in Fig. 1 (old instrument) and Fig. 2 (newinstrument).5.1.1 Integrated or Separat
18、e Control UnitThe control unit shall provide a continuous, linear temperature increase from 25 Cto 250 C at a rate of 2 C/min. A digital readout shall indicate the temperature to 0.1 C throughout.5.1.2 Integrated or Separate Furnace UnitThe furnace unit shall be capable of heating one or two sample
19、cup assemblies, asdescribed in 5.1.3, at a linear rate of 2 C 6 0.3 Cmin. It shall include a sensing system capable of detecting the softening pointwith a precision of 0.1 C.5.1.3 Sample Cup AssemblyA cup of chromium-plated brass, or of aluminum, or of stainless steel conforming to therequirements f
20、or Type 303 (UNS S30300) stainless steel as prescribed in Specification A314, with the dimensions shown in Fig.3. It shall be placed in the assembly so that the pitch sample softening point will be detected when it has flowed down a distanceof 19 mm.FIG. 1 General View of the METTLER TOLEDO FP90 Con
21、trol Unit with Heater FP83HTD3461 182FIG. 2 General View of the METTLER TOLEDO DP70FIG. 3 Specimen CupD3461 1835.1.4 Lead BallA lead ball weighing 3.20 g 6 0.10 g. between 3.00 g and 3.30 g. A 32-caliber lead shot is suitable for thispurpose.6. Reagents6.1 Xylene, industrial grade.7. Calibration of
22、METTLER TOLEDO Apparatus7.1 This step, required only occasionally, is designed to establish that the temperature indicated by the instrument is inagreement with a known standard.Aspecial cup with a bottom orifice of 2.8 mm is used instead of the one prescribed for the testingof pitch.7.2 ReagentUse
23、either analytical reagent or primary standard grade benzoic acid for the calibration. As this material ishygroscopic it must be stored in a tightly sealed container, and replaced with fresh material from a newly opened supply ifhydration or other contamination is suspected.D3461 1847.3 ProcedureOld
24、Instruments:7.3.1 Filling the Sample CupPlace the cup on a clean, flat surface. Add a small amount of benzoic acid crystals and pressdown with a rod (approximately 4.5 mm in diameter). Check that the bottom orifice is completely filled. Refill and repeat thepressing step until the cup is filled with
25、 benzoic acid. Remove any crystals from the exterior of the cup.7.3.2 HeatingPreheat the Mettler furnace to 121 C, and maintain it at that temperature. Place the cartridge assemblycontaining the benzoic acid in position in the furnace, taking care that the slits for the light beam are properly posit
26、ioned. Waitfor temperature equilibration, that is, the furnace and the sample are in equilibrium at the preset temperature, but not less than the30 s after inserting the cartridge, start the automatic heating cycle at 0.2 C/min. The temperature will rise steadily at the correctrate until the drop po
27、int is reached, and then remain steady on the readout.7.3.3 CleaningImmediately remove the cartridge assembly. Check to determine that the sample has passed through the lightbeam and no pre-triggering has occurred. If a malfunction is suspected, the entire procedure must be repeated. Inspect the app
28、aratuscarefully to ensure that no residue remains. Use a spatula shaped to the contour of the cup to remove most of the remaining acidfrom the cup and from the bottom of the cartridge. Wash the cup and cartridge in xylene, or other suitable solvent, to remove thelast traces of the residue.7.4 Interp
29、retationSee 7.6.7.5 ProcedureNew Instruments:7.5.1 Filling the Sample CupPlace the cup on a clean, flat surface. Optionally, the sample preparation tool may be used. SeeFig. 2. Add a small amount of benzoic acid crystals and press down with a rod (approximately 4.5 mm in diameter). Check thatthe bot
30、tom orifice is completely filled. Refill and repeat the pressing step until the cup is filled with benzoic acid. Remove anycrystals from the exterior of the cup. Place a glass collector below the cup and a cup cap on top, and place in the sample carrier.Two cup assemblies may be placed in the sample
31、 carrier.7.5.2 HeatingPreheat the furnace to 121 C and maintain it at that temperature. Place the sample carrier containing thebenzoic acid in position in the furnace. Wait for temperature equilibration, that is, the furnace and the sample are in equilibriumat the preset temperature, but not less th
32、an 30 s after inserting the cartridge, start the automatic heating cycle at 0.2 C/min. Thetemperature will rise steadily at the correct rate until the drop point is reached, and then remain steady on the readout. If there aretwo samples, heating will continue until both have dropped.7.5.3 CleaningIm
33、mediately remove the cartridge assembly. Check to determine that the sample has dropped and nopre-triggering has occurred. The video may be viewed to make sure the drop was detected correctly. If a malfunction is suspected,the entire procedure must be repeated. Inspect the apparatus carefully to ens
34、ure that no residue remains. Use a spatula shaped tothe contour of the cup to remove most of the remaining acid from the cup. Wash the cup and glass collector in xylene, or othersuitable solvent, to remove the last traces of the residue. Glass collectors may be treated as disposable items.Aluminum c
35、ups maybe used which may also be considered to be disposable.7.6 InterpretationIf the result is not 123.5 C 6 0.5 C, repeat the test. If the second value is 0.6 C above or below 123.5C, measure the dropping point of a fresh sample of benzoic acid. If the deviation exceeds 0.6 C, the instrument requi
36、resrecalibration or repair. Consult the manufacturers instruction manual.8. Sampling8.1 Samples from shipments shall be taken in accordance with Practice D140 for asphalt and Practice D4296 for pitch and shallbe free of foreign substances. Thoroughly mix the sample before removing a representative p
37、ortion for the determination or fordehydration.8.2 Pitch Sample Preparation:8.2.1 If a solid bulk sample contains free water, air-dry a representative portion at 60 C or below.8.2.2 If the sample is liquid, check for any surface foam which may indicate the presence of water. If foam is found, mainta
38、inthe sample at a temperature of about 125 C in an open container until the surface is free of foam. Take care not to overheat.Remove from the heat source as soon as the foam has subsided. Proceed as directed in 9.1.8.2.3 Crush air-dry lumps of pitch to a size of 6 mm to 12 mm. Add the material to a
39、 container, having a height equal to orexceeding its width, and having a volume of not less than 50 mL, until it is about half full. Place the container on a hot plate, orin an oven or a bath. Do not use an open flame for melting pitch. After melting is complete, stir gently but thoroughly, avoiding
40、incorporation of air bubbles. The maximum temperature of the molten pitch should not exceed the expected softening point bymore than 50 C. Any foam that forms must be skimmed off.8.3 Asphalt Sample Preparation:8.3.1 Heat the sample, with care to prevent local overheating, constantly stirring until i
41、t has become sufficiently fluid to pour.In no case, however, shall the temperature be raised more than 110 C (200 F) above the expected softening point for asphalt.Avoid incorporating air bubbles in the sample.8.3.2 Bring the asphalt sample to the pouring temperature in not more than 2 h.D3461 1859.
42、 Test Specimen9.1 Prepare the test specimen by slightly overfilling the specimen cup, which rests on a brass plate. Optionally, the samplepreparation tool may be used (see Fig. 2). Keep the lip of the container close to the top of the cup to minimize entrainment of airbubbles. Under-pouring past the
43、 blade of a spatula is helpful in this respect. Cool the specimen in the cup until firm, under coldwater if necessary. Trim the specimen flush with the top of the cup by pressing with a heated knife or spatula while drawing ittoward you. Support the cup with tweezers or forceps or in a wood block wi
44、th holes sized to fit the cup. Do not trim by cuttingacross the top with a forward or sideward motion as this tends to lift the specimen out of the mold, thus creating an internal voidwhich is not easily detected, and which significantly alters the result.9.2 An alternative method which avoids possi
45、ble loss of volatiles in re-melting, is to press the cold, solid specimen into thespecimen cup. Select clean, dry, dust-free lumps from the representative portion of the sample and crush to a size of less than 2mm. Place a sample cup in the mold (see Fig. 4, Fig. 5, and Fig. 6). Place the assembled
46、mold, with the knockout pin in position,on the bottom plate of a hydraulic press. Pour about 2 g of the crushed specimen into the top of the mold and insert the top ram.Compress the specimen into the cup with a total force on the ram of 22.24 kN (5000 lb). Hold this pressure for a minimum of 15s. Ex
47、cessive molding pressure can cause the specimen cup to fail by shearing. Remove the mold assembly from the press and rotatethe upper half while keeping the lower half of the mold stationary. This action causes the specimen to shear horizontally at thetop of the cup. Separate the two parts of the mol
48、d and remove the specimen cup from the bottom half. It may be necessary todislodge it by pressing against the knockout pin. A small-diameter rod mounted on the base plate may be used for this. Clean themold of all residual material to avoid misalignment or binding during subsequent use. This procedu
49、re does not work well forpitches having softening points below 80 C unless the mold is precooled below room temperature.NOTE 1Diameters are concentric. These two parts will be hardened tool steel and then ground to final dimensions.All dimensions are in millimetres.FIG. 4 Upper Half of Mold Assembly for Pressure Molding Asphalt and Pitch into a Specimen CupD3461 18610. Procedure10.1 The procedure described in this test method for measuring the softening point of asphalts and pitches using eitherMETTLER TOLEDO instrumen
