1、Designation: D6307 16Standard Test Method forAsphalt Content of Asphalt Mixture by Ignition Method1This standard is issued under the fixed designation D6307; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. 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 determination of asphaltcontent of asphalt mixture and asphalt pavement samples byremoving the asphalt
3、cement in an ignition furnace. The meansof sample heating may be the convection method or directirradiation method.NOTE 1Aggregate obtained by this test method may be used for sieveanalysis. Particle size degradation may occur with some aggregates.1.2 The values stated in SI units are to be regarded
4、 asstandard. No other units of measurement are included in thisstandard.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 t
5、he applica-bility of regulatory limitation prior to use.2. Referenced Documents2.1 ASTM Standards:2C670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsC702 Practice for Reducing Samples ofAggregate to TestingSizeD75 Practice for Sampling AggregatesD140
6、 Practice for Sampling Bituminous MaterialsD979 Practice for Sampling Bituminous Paving MixturesD1461 Test Method for Moisture or Volatile Distillates inBituminous Paving MixturesD4753 Guide for Evaluating, Selecting, and Specifying Bal-ances and Standard Masses for Use in Soil, Rock, andConstructio
7、n Materials TestingD5444 Test Method for Mechanical Size Analysis of Ex-tracted Aggregate2.2 AASHTO Standards:3R47 Standard Practice for Reducing Samples of Hot MixAsphalt (HMA) to Testing Size3. Summary of Test Methods3.1 The asphalt cement in the paving mixture is ignitedusing the furnace equipmen
8、t applicable to the particularmethod. The asphalt content is calculated by difference fromthe mass of the residual aggregate and moisture content. Theasphalt content is expressed as mass percent of moisture-freemixtures. Test Method A is intended for furnaces with aninternal, automated weighing syst
9、em. Test Method B is in-tended for furnaces without an internal weighing system.4. Significance and Use4.1 This test method can be used for quantitative determi-nation of asphalt content in asphalt mixture and pavementsamples for quality control, specification acceptance, andmixture evaluation studi
10、es. This test method does not requirethe use of solvents. Aggregate obtained by this test methodmay be used for gradation analysis according to Test MethodD5444.5. Apparatus5.1 Balance, readable to 0.1 g, and capable of measuring themass of sample, sample trays, and catch pan. The balance shallbe in
11、 accordance with Guide D4753, Class GP2.5.2 Sample Tray(s), of appropriate size that allows thesamples to be spread thinly and allows air to flow up throughand around the sample particles. The sample shall be enclosedcompletely with screen mesh, perforated stainless steel plate,or other suitable mat
12、erial.NOTE 2Screen mesh or other suitable material with maximum andminimum openings of 3.35 mm and 600 m, respectively, has been foundto perform well.5.3 Catch Pan, of appropriate size to hold the sample traysso that aggregate particles and melting asphalt binder fallingthrough the screen mesh are c
13、aught.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.25 onAnalysis of Asphalt Mixtures.Current edition approved May 1, 2016. Published July 2016. Originally approvedin 1998. Last previous edition appr
14、oved in 2010 as D6307 10. DOI: 10.1520/D6307-16.2For 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.3Available fr
15、om American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.4 Catch Pan/Sample T
16、ray(s) Handling Apparatus, suitablefor inserting catch pan and sample tray(s) into furnace andremoving hot catch pan and sample tray(s) from furnace.5.5 Assorted Spatulas, Pans, Bowls, and Wire Brushes, forpreparing asphalt mixtures and removing aggregate fromsample tray(s) and catch pan.5.6 Protect
17、ive Gloves, well insulated and capable of with-standing 580C.5.7 OvensMechanical ovens, convection or forced draft,shall be provided for drying aggregates and asphalt mixtures,and for preheating asphalt mixtures prior to ignition testing.5.8 Ignition Furnace, as described in 8.1.1 or 11.1.1.6. Hazar
18、ds6.1 The temperature of the furnace, sample, sample tray(s),and catch pan after removal from the furnace is extremely high.Caution, therefore, must be exercised at all times whenhandling these items as failure to do so could result in seriousinjury, severe burns, or fire. The sample, sample tray(s)
19、, andcatch pan should be placed inside a safety cage and should notbe allowed to cool near any materials that are subject toignition at the high temperatures used in this procedure. Thefurnace manufacturers instruction manual must be followed totake all necessary precautions.7. Sampling7.1 Obtain sa
20、mples of aggregate in accordance with PracticeD75.7.2 Obtain samples of asphalt mixture in accordance withPractice D979 and AASHTO R47.7.3 Preparation of Test Specimens:7.3.1 If the mixture is not soft enough to separate with aspatula or trowel, place it in a large, flat pan and warm in anoven set a
21、t 110 6 5C until it can be separated or mixed. Splitor quarter the material in accordance with Practice C702 untilthe mass of material required for the test is obtained.7.3.2 The size of the test sample shall be governed by thenominal maximum aggregate size of the mixture and shallconform to the mas
22、s requirement shown in Table 1 (see Note3).NOTE 3When the mass of the test specimen exceeds the capacity ofthe equipment used (for a particular method), the test specimen may bedivided into suitable increments, tested, and the results combined forcalculation of asphalt content based on the weighted
23、average of the massesused in the increments.7.4 Obtain samples of asphalt cement in accordance withPractice D140.TEST METHOD A8. Apparatus8.1 In addition to the apparatus listed in Section 5, thefollowing apparatus is required for Test Method A.8.1.1 Ignition FurnaceA forced air ignition furnace tha
24、theats the sample by either convection method or direct-irradiation method. The convection-type furnace must have aminimum temperature capability of 580C. The furnace shallhave an internal weighing system capable of measuring themass of sample sizes of at least 2500 g. The furnace chambershall be of
25、 sufficient size to accommodate sample sizes of atleast 2500 g. A data collection system also shall be included sothat the sample mass loss can be determined automatically toan accuracy of 0.1 g and displayed during a test. The test isdeemed complete when the difference between consecutivemeasured m
26、ass loss does not exceed 0.01 % of the sample massfor three consecutive 1-min intervals. The equipment shallprovide a printout of the test results. A system capable ofreducing furnace emissions to an acceptable level also shall beincorporated in the furnace. The furnace shall be vented into ahood or
27、 to the outside and when set up properly will have nonoticeable odors escaping into the laboratory. The furnace willhave a fan with the capability to pull air through the furnace toexpedite the test and to reduce escape of smoke into thelaboratory. The furnace shall be equipped so that the doorcanno
28、t be opened during the ignition test.8.1.2 Filters, if required, of the type specified by the furnacemanufacturer.9. Calibration9.1 The type of aggregate in the mixture may affect theresults of this test method because different aggregates losemass on ignition to varying degrees. The results also ma
29、y beaffected by the presence of additives and modifiers in theasphalt mixture sample. Accordingly, to optimize accuracy, acalibration factor shall be established by testing three calibra-tion samples for each mix type. The calibration shall beperformed on a prepared sample of asphalt mixture, which
30、alsoshall include additives and modifiers, if any, to be used.9.2 Obtain samples of blended aggregate to be used in theasphalt mixture in accordance with 7.1. The sample should beapproximately the same mass and gradation as that to be usedfor the asphalt mixture test sample (10.1).9.3 Obtain samples
31、 of asphalt cement to be used in theasphalt mixture in accordance with 7.4.9.4 Oven-dry the aggregate samples to a constant mass.9.4.1 For the convection-type furnace, set the furnace tem-perature to 540 6 5C for calibration using mixtures.9.4.2 For the direct-irradiation-type furnace, set the burnp
32、rofile to the DEFAULT mode.9.5 Heat the aggregates and asphalt cement to approxi-mately 150C. Heat all mixing bowls and tools to approxi-mately 150C.9.6 Prior to the mixing of calibration samples, an initial or“butter” mix is required to condition the mixing equipment.TABLE 1 Size of SampleNominal M
33、aximum Aggregate SizeStandard, mm Minimum Mass of Sample, kg4.75 0.59.5 112.5 1.519.0 225.0 337.5 4D6307 162Remove and discard the “butter” mix from the bowl byscraping, leaving a uniform coating of asphalt mix residue.NOTE 4The “butter” mix prevents calibration samples from beingbiased by residual
34、asphalt mix retained in the mixing bowl.9.7 Prepare three calibration samples at the design asphaltcement content (P). Incorporate additives and modifiers, if any,to be used.9.8 Determine and record the mass of the sample tray(s) andcatch pan to the nearest 0.1 g.9.9 Evenly distribute the sample in
35、the sample tray(s).9.10 Determine the mass of the sample, sample tray(s), andcatch pan to the nearest 0.1 g. Calculate and record the initialmass of the sample (MI).9.11 Heat the calibration sample in the convection-typefurnace at 540 6 5C; or in the direct irradiation type furnaceusing the DEFAULT
36、mode until the change in mass of thesample during three consecutive 1-min intervals does notexceed 0.01 % of the sample mass (MI).9.12 Measure and record the mass (ML) of the sample afterignition to the nearest 0.1 g. The mass can be obtainedimmediately upon completion of the test from the printout
37、ordisplay.9.13 Calculate the calibration factor (CF) as follows:CF5SMI2 MLMI3100D2 P (1)where:MI= total mass of the mixture calibration sample prior toignition,ML= total mass of the mixture calibration sample afterignition, andP = percentage of actual asphalt cement in the mix bymass of the total mi
38、x expressed as a percentage.9.14 Repeat steps 9.8 9.13 for two additional calibrationsamples. Calculate the average calibration factor (CF)byaveraging the three CFvalues.9.15 Calibration Temperature Adjustments9.15.1 For the convection-type furnace, if the calibrationfactor exceeds 1.0 %, lower the
39、test temperature to 482 6 5Cand repeat steps 9.2 9.14 . Use the calibration factor obtainedat 482C even if it exceeds 1.0 %.9.15.2 For the direct irradiation-type furnace, the DE-FAULT burn profile should be used for most materials. Theoperator may select burn profile OPTION 1 or OPTION 2 tooptimize
40、 the burn cycle. OPTION 1 is designed for aggregateswith correction factor greater than 1.0 percent. OPTION 2 isdesigned for samples that may not burn completely using theDEFAULT burn profile.9.16 The temperature or burn profile for testing asphaltmixture samples in 10.3 shall be the same temperatur
41、e or burnprofile selected for testing mixture calibration samples.10. Procedure10.1 Obtain an asphalt mixture sample in accordance withSection 7. The sample mass should be approximately the sameas that used for calibration (9.2).10.2 Oven dry the asphalt mixture sample to constant massat a temperatu
42、re of 110 6 5C or determine the moisturecontent of samples in accordance with Test Method D1461,sothat the measured mass loss can be corrected for moisture.10.3 Set the furnace temperature or burn profile in accor-dance with Section 9. Samples can be placed in the furnace atsignificantly lower tempe
43、ratures, since the furnace will quicklyheat to the desired temperature once the sample begins to burn.The furnace temperature is likely to increase during theignition phase of the test.10.4 Determine and record the mass of the sample tray(s)and catch pan to the nearest 0.1 g.10.5 Evenly distribute t
44、he sample in the sample tray(s).10.6 Determine the mass of the sample, sample tray(s), andcatch pan to the nearest 0.1 g. Calculate and record the initialmass of the sample (MB).10.7 Heat the sample in the furnace at the specified tem-perature until the difference between consecutive measuredmass lo
45、ss does not exceed 0.01 % of the sample mass (MB) forthree consecutive 1-min intervals. This point shall be deter-mined automatically by the furnaces data collection system.10.8 The furnaces data collection system shall measure andrecord automatically the aggregate mass (MA) of the sampleafter ignit
46、ion to the nearest 0.1 g. The mass shall be obtainedimmediately upon completion of tests by subtracting the massloss measured by the furnace from the initial mass of the mix(MB).10.9 The corrected asphalt content shall be calculated auto-matically by the furnaces data collection system as follows:%
47、AC 5SMB2 MAMB3100D2 CF(2)where:AC = measured asphalt content percent by mass of theoven-dry asphalt mixture sample,MA= total mass of aggregate remaining after ignition,MB= total mass of the asphalt mixture sample prior toignition, andCF= calibration factor obtained in Section 9 and enteredinto the f
48、urnaces data collection system.TEST METHOD B11. Apparatus11.1 In addition to the apparatus listed in Section 5, thefollowing apparatus is required for Test Method B.11.1.1 Furnace, having a minimum temperature capabilityof 580C and equipped with a fan capable of pulling airthrough the furnace to exp
49、edite the test and to reduce escape ofsmoke into the laboratory. The furnace chamber shall be ofsufficient size to accommodate samples sizes of at least 2500 g.A system capable of reducing furnace emissions to an accept-able level also shall be incorporated in the furnace. The furnaceshall be vented into a hood or to the outside, and when set upproperly, will have no noticeable odors escaping into theD6307 163laboratory. The furnace shall be equipped so that the doorcannot be opened during the ignition test.11.1.2 Filters, if required, of the type spec
