1、Designation: D1856 09 (Reapproved 2015)Standard Test Method forRecovery of Asphalt From Solution by Abson Method1This standard is issued under the fixed designation D1856; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 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. Scope1.1 This test method covers the recovery by the Absonmethod of asphalt from a solution from a previously conductedextract
3、ion. The asphalt is recovered with properties substan-tially the same as those it possessed in the bituminous mixtureand in quantities sufficient for further testing.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are provided forinformation only.
4、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 practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced D
5、ocuments2.1 ASTM Standards:2C670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsD2172 Test Methods for Quantitative Extraction of BitumenFrom Bituminous Paving MixturesD2939 Test Methods for Emulsified Bitumens Used asProtective Coatings (Withdrawn 201
6、2)3D4080 Specification for Trichloroethylene, Technical andVapor-Degreasing GradeD6368 Specification for Vapor-Degreasing Solvents Basedon normal-Propyl Bromide and Technical Grade normal-Propyl BromideE1 Specification for ASTM Liquid-in-Glass Thermometers3. Summary of Test Method3.1 The solution of
7、 solvent and asphalt from an asphalt mixextraction is distilled under prescribed conditions to a pointwhere most of the solvent has been distilled, at which timecarbon dioxide gas is introduced into the distillation process toremove all traces of the extraction solvent. The recoveredasphalt (distill
8、ation residue) can then be subjected to furthertesting as required.4. Significance and Use4.1 The asphalt should be extracted from the aggregate-asphalt mixture in accordance with Method A of Test MethodsD2172 (centrifuge method) as there is some experimentalevidence that the recovered asphalt may h
9、ave slightly lowerpenetration values when recovered from solutions obtainedfrom hot extraction methods.5. Apparatus5.1 Centrifuge, batch unit capable of exerting a minimumcentrifugal force of 770 times gravity or continuous unitcapable of exerting a minimum force of 3000 times gravity.5.2 Centrifuge
10、 TubesA supply of wide-mouth bottles orcentrifuge tubes may be used for the batch unit. A tube asillustrated in Fig. 1 has been found satisfactory for thecontinuous unit.5.3 Distillation Assembly, as shown in Fig. 2, and consistingof the following items:5.3.1 Extraction FlasksTwo 250-ml, wide-mouth,
11、 heat-resistant flasks, one for distillation and the other for thereceiver.5.3.2 Glass TubingHeat-resistant glass tubing, having10-mm inside diameter and gooseneck shaped (as shown inFig. 2) for connecting the flask to the condenser.5.3.3 Inlet Aeration Tube,4at least 180 mm in length, havinga 6-mm
12、outside diameter with a 10-mm bulb carrying sixstaggered side holes approximately 1.5 mm in diameter.5.3.4 Electric Heating Mantle, with variable transformer, oilbath, or fluidized sand bath, to fit a 250-ml flask.5.3.5 Water-Jacketed Condenser, Allihn type, with 200-mmminimum jacket length or equiv
13、alent.1This method is under the jurisdiction of ASTM Committee D04 on Road andPaving Materials and is the direct responsibility of Subcommittee D04.25 onAnalysis of Asphalt Mixtures.Current edition approved Jan. 1, 2015. Published February 2015. Originallyapproved in 1961. Last previous edition appr
14、oved in 2009 as D1856 09. DOI:10.1520/D1856-09R15.2For 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 website.3The last a
15、pproved version of this historical standard is referenced onwww.astm.org.4The sole source of supply of the apparatus known to the committee at this timeis Inlet Aeration Tube, Part No. 226, available from Wm. A. Sales, Ltd., 419Harvester Court, Wheeling, Ill. 60090; request Part No. 226. If you are
16、aware ofalternative 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohoc
17、ken, PA 19428-2959. United States1FIG. 1 Centrifuge Tube ExampleFIG. 2 Distillation Assembly for Bitumen RecoveryD1856 09 (2015)25.3.6 ThermometerAnASTM Low Distillation Thermom-eter 7E or 7F, as specified, having a range from 2 to 300C or30 to 580F, respectively, and conforming to the requirementsi
18、n Specification E1.5.3.7 Gas Flowmeter,5as shown in Fig. 2, or any flowmetercapable of indicating a gas flow of up to 1000 ml/min.5.3.8 Corks, No. 20, drilled as shown in Fig. 2.5.3.9 Flexible Elastomeric Tubing, resistant to chlorinatedsolvents having sufficient length and size to connect theaerati
19、on tube to flowmeter, and equipped with a pinch clamp orstopcock to close aeration tube prior to introducing carbondioxide.5.3.10 Separatory Funnel,6(Alternative Procedure, see9.3.1) 125-ml capacity.6. Reagents and Materials6.1 Carbon Dioxide GasA pressurized tank, withpressure-reducing valve or oth
20、er convenient source.6.2 Solvents6.2.1 The solvent for extracting the asphalt from mixturesmay be trichloroethylene, conforming with SpecificationD4080.76.2.2 The solvent for extracting the asphalt from mixturesmay be Normal Propyl Bromides (nPB). This solvent shouldconform to Specification D6368.86
21、.2.3 The solvent for extracting the asphalt from mixturesmay be reagent grade Methylene Chloride.87. Precautions7.1 WarningThe solvent listed in 6.2 should be used onlyunder a hood or with an effective surface exhaust system in awell-ventilated area, since they are toxic to various degrees.Consult t
22、he current Threshold Limit Concentration Committeeof the American Conference of Governmental Industrial Hy-gienists for the current threshold limit values.7.2 These solvents in the presence of heat and moisture maybe hydrolyzed to form acids that are extremely corrosive tocertain metals, particularl
23、y when subject to contact overlengthy periods of time. Proper precautions should be taken tonot allow these solvents to remain in small quantities in theeffluent tanks of aluminum vacuum extractors.7.3 Exposure of these solvents or their vapors to hightemperatures such as contact with flames, hot gl
24、owing surfaces,or electric arcs can produce decomposition products such ashydrogen chloride. Steel drums containing these solventsshould be stored in a cool, dry location, kept tightly sealed, andopened as infrequently as possible. The hydrogen chloride indecomposed solvent may harden an asphalt dur
25、ing the extrac-tion and recovery test.8. Sample8.1 The sample shall consist of the solution from a previousextraction by Method A of Test Methods D2172 of asphalt-aggregate mixture of sufficient quantity to result in 75 to 100 gof recovered bitumen. More or less quantities of bitumen maybe recovered
26、; however, the properties of the recovered bitumenmay not be in agreement with those recovered of the afore-mentioned quantities, and in case of a disagreement, 75 to 100g should be recovered.8.2 During the extraction process, it is important that all ofthe asphalt in the mixture be extracted as the
27、re could be someselective solvency of the asphalt and the harder, more viscouscomponents of the asphalt might be left in the mixture ifextraction is not carried to completion.8.3 Since heavy petroleum distillates such as mineral spiritsor kerosine will affect the properties of the recovered asphalt,
28、it is important to avoid the use of such solvents in cleaning theextraction and recovery apparatus and use only trichloroethyl-ene for cleaning. Residues of heavy petroleum solvents on theequipment may contaminate the recovered asphalt and affect itstest properties. It is also necessary to use new f
29、ilter rings, cleanfelt pads, or other uncontaminated filtering media in theextraction process to avoid contamination from a previousextraction.8.4 Generally, the bitumen in mixtures will progressivelyharden when exposed to air, particularly if the mixtures are ina loose condition. Therefore, it is i
30、mportant to protect bitumi-nous mixtures from exposure to air and preferably to storethem in airtight containers at a temperature below 0C (32F)until they can be tested. When samples of bituminous mixtureare warmed for preparing representative proportions for extrac-tion tests in accordance with Met
31、hod A of Test MethodsD2172, they should be placed in an oven in covered containersand heated to a maximum temperature of 110C (230F) for theminimum time to obtain workability, but no longer than 30min. If the samples have been stored at a low temperature, theyshould be allowed to reach room temperat
32、ure before placingthem in the oven.9. Procedure9.1 The entire procedure, from the start of the extraction tothe final recovery, must be completed within 8 h.9.2 Centrifuge the solution from the previous extraction fora minimum of 30 min at 770 times gravity in either bottles orcentrifuge tubes in th
33、e specified batch apparatus. If a continu-ous centrifuge is used, the extract solution shall be charged ata rate not to exceed 150 ml/min, while the unit is operating at5The sole source of supply of the apparatus known to the committee at this timeis The Monostat Corp. “Flowmeter” No. 9144. If you a
34、re aware of alternativesuppliers, please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.6The sole source of supply of the apparatus known to the committee at this ti
35、meis Kimball separatory funnel No. 29028. If you are aware of alternative suppliers,please provide this information to ASTM International Headquarters. Your com-ments will receive careful consideration at a meeting of the responsible technicalcommittee,1which you may attend.7The sole source of suppl
36、y of the apparatus known to the committee at this timeis American Conference of Governmental Industrial Hygienists, Inc. (ACGIH),1330 Kemper Meadow Dr., Cincinnati, OH 45240, (http:/www.acgih.org). If youare aware of alternative suppliers, please provide this information to ASTMInternational Headqua
37、rters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.8It is recommended that for each new supply of the solvent a blank should be runon an asphalt of known properties.D1856 09 (2015)3a speed calculated to produce a centrifug
38、al force of not lessthan 3000 times gravity.9.3 Concentrate the solution to about 200 ml by any primarydistillation operation using a flask large enough to hold all thesolution from the extraction. Transfer the residue from theprimary distillation flask, using several washes of solvent torinse all o
39、f the residue into the 250-ml distillation flask.Assemble the apparatus as shown in Fig. 2, except position thebottom of the aeration tube above the surface of the solution.Continue distillation until the temperature reaches 135C(275F), at which time lower the aeration tube so that the bulbis in con
40、tact with the bottom of the flask, and introduce carbondioxide gas at a low rate (approximately 100 ml/min) toprovide agitation and prevent foaming. If foaming or bumpingoccurs, introduce carbon dioxide intermittently at the begin-ning of the distillation at a rate of 100 ml/min to prevent this.When
41、 the temperature reaches 157 to 160C (315 to 320F),increase the carbon dioxide gas flow to approximately 900mL/min. Maintain this gas flow rate for 10 min while alsomaintaining the temperature of the residue in the flask at 160 to166C (320 to 330F). If, after 10 min, dripping of condensedsolvent fro
42、m the delivery tube is still occurring, maintain thegas flow and temperature until 5 min after the dripping ceasesin order to flush solvent vapors from the flask. In no case shallthe time of flow of carbon dioxide gas be less than 15 min. Atthe end of this period, discontinue gas flow and heat.9.3.1
43、 Alternative ProcedureAssemble the apparatus asshown in Fig. 2 with the separatory funnel in the thermometerhole in the cork. (It may be advantageous to insert theseparatory funnel in a separate hole drilled in the cork stopper.)Raise the aeration tube so that the bulb is above the surface ofthe sol
44、ution. Fill the separatory funnel with the centrifugedsolution and open the stopcock to fill the flask approximatelyone half full of solvent mixture.Apply low heat to the flask andstart distillation. Adjust the funnel stopcock to introduce freshsolvent at a rate that will keep the flask approximatel
45、y one halffull during distillation, adding additional solvent mixture to thefunnel until all solvent has been introduced into the distillationflask. Wash the solvent mixture container and funnel with freshsolvent to transfer all asphalt into the distillation flask. Con-tinue distillation until the t
46、emperature reaches 135C (275F),at which time lower the aeration tube so that the bulb is incontact with the bottom of the flask and introduce carbondioxide gas at a low rate (approximately 100 ml/min) toprovide agitation and prevent foaming. If foaming or bumpingoccurs, introduce carbon dioxide inte
47、rmittently at the begin-ning of the distillation at a rate of 100 ml/min to prevent this.When the temperature reaches 157 to 160C (315 to 320F),increase the carbon dioxide gas flow to approximately 900mL/min. Maintain this gas flow rate for 10 min while alsomaintaining the temperature of the residue
48、 in the flask at 160 to166C (320 to 330F). If, after 10 min, dripping of condensedsolvent from the delivery tube is still occurring, maintain thegas flow and temperature until 5 min after the dripping ceasesin order to flush solvent vapors from the flask. In no case shallthe time of flow of carbon d
49、ioxide gas be less than 15 min. Atthe end of this period, discontinue the gas flow and heat.9.4 If the residue in the flask is highly viscous at 163C(325F), so that dispersion of the carbon dioxide in the residueis restricted and the recovered asphalt is expected to have apenetration at 25C (77F) of less than 30, maintain the carbondioxide gas flow and temperature for 20 to 22 min.9.5 The recovered asphalt can be heated to reliquefy andportions taken for penetration, softening point, ductility, ashcontent, and kinematic and absolute viscosity determi
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