1、Designation: D6307 10Standard Test Method forAsphalt Content of Hot-Mix Asphalt 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 hot-mix asphalt (HMA) paving mixtures and pave-ment samples by remov
3、ing the asphalt cement in an ignitionfurnace. The means of sample heating may be the convectionmethod or direct irradiation 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 ar
4、e to be regarded 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
5、 and determine the 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 of Aggregate to Test-ing SizeD75 Practice for Samp
6、ling AggregatesD140 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 SpecifyingBalances and Standard Masses for Use in Soil, Roc
7、k, andConstruction Materials TestingD5444 Test Method for Mechanical Size Analysis of Ex-tracted Aggregate3. Summary of Test Methods3.1 The asphalt cement in the paving mixture is ignitedusing the furnace equipment applicable to the particularmethod. The asphalt content is calculated by difference f
8、romthe 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 system. Test Method B is in-tended for furnaces without an internal weighing system.4. Sign
9、ificance and Use4.1 This test method can be used for quantitative determi-nation of asphalt content in HMA paving mixtures and pave-ment samples for quality control, specification acceptance, andmixture evaluation studies. This test method does not requirethe use of solvents. Aggregate obtained by t
10、his 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 accordance with Guide D4753, Class GP2.5.2 Sample Tray(s), of appropriate size t
11、hat 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 material.NOTE 2Screen mesh or other suitable material with maximum andminimum openin
12、gs 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 caught.5.4 Catch Pan/Sample Tray(s) Handling Apparatus, suitablefor inserting catc
13、h pan and sample tray(s) into furnace andremoving hot catch pan and sample tray(s) from furnace.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 Bituminous Mixtures.Current edition appr
14、oved Dec. 1, 2010. Published March 2011. Originallyapproved in 1998. Last previous edition approved in 2005 as D6307 05. DOI:10.1520/D6307-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vol
15、ume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.5 Assorted Spatulas, Pans, Bowls, and Wire Brushes, forpreparing HMAmixtures and removing aggregate fr
16、om sampletray(s) and catch pan.5.6 Protective Gloves, well insulated and capable of with-standing 580C.5.7 OvensMechanical ovens, convection or forced draft,shall be provided for drying aggregates and HMA mixtures,and for preheating HMA mixtures prior to ignition testing.5.8 Ignition Furnace, as des
17、cribed in 8.1.1 or 11.1.1.6. Hazards6.1 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, o
18、r fire. The sample, sample tray(s), 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 pr
19、ecautions.7. Sampling7.1 Obtain samples of aggregate in accordance with PracticeD75.7.2 Obtain samples of HMA in accordance with PracticeD979.7.3 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 anove
20、n set at 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
21、the mass 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 we
22、ighted 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 furn
23、ace thatheats 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 chambershal
24、l be of 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 consecutivemea
25、sured mass 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 a
26、hood or 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 do
27、orcannot 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
28、also may beaffected by the presence of additives and modifiers in the HMAsample. Accordingly, to optimize accuracy, a calibration factorshall be established by testing three calibration samples foreach mix type. The calibration shall be performed on aprepared sample of asphalt mixture, which also sh
29、all includeadditives and modifiers, if any, to be used.9.2 Obtain samples of blended aggregate to be used in HMAin accordance with 7.1. The sample should be approximatelythe same mass and gradation as that to be used for the HMAtest sample (10.1).9.3 Obtain samples of asphalt cement to be used in HM
30、A inaccordance 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 burnprofile to the DEFAULT mode.9.5 Heat the aggregates
31、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.Remove and discard the “butter” mix from the bowl byscraping, leaving a uniform co
32、ating of asphalt mix residue.NOTE 4The “butter” mix prevents calibration samples from beingbiased by residual 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.TABLE 1 Size of
33、SampleNominal Maximum Aggregate SizeStandard, mm Minimum Mass of Sample, kg4.75 0.59.5 112.5 1.519.0 225.0 337.5 4D6307 1029.8 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 the sample tray(s).9.10 Determine the mass of the s
34、ample, 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 mode until the change in mass of thesample during t
35、hree 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 ordisplay.9.13 Calculate the calibration factor (CF
36、) as follows:CF5SMI MLMI3 100D 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 mix expressed as a percentage.9.14 Repeat steps 9.8 th
37、rough 9.13 for two additionalcalibration samples. Calculate the average calibration factor(CF) by averaging the three CFvalues.9.15 Calibration Temperature Adjustments9.15.1 For the convection-type furnace, if the calibrationfactor exceeds 1.0 %, lower the test temperature to 482 6 5Cand repeat step
38、s 9.2 through 9.14. Use the calibration factorobtained at 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 the burn cycle. OPTION 1 is designe
39、d 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 HMAsamples in 10.3 shall be the same temperature or burn profileselected for testing mixture ca
40、libration samples.10. Procedure10.1 Obtain an HMA sample in accordance with Section 7.The sample mass should be approximately the same as thatused for calibration (9.2).10.2 Oven dry the HMA sample to constant mass at atemperature of 110 6 5C or determine the moisture content ofsamples in accordance
41、 with Test Method D1461, so that themeasured 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 temperatures, since the furnace will quicklyheat to the desired temperature
42、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 the sample in the sample tray(s).10.6 Determine the mass of the sample,
43、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 loss does not exceed 0.01 % of the sample mass (MB) forthree consecutive
44、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 ignition to the nearest 0.1 g. The mass shall be obtainedimmediately upon co
45、mpletion 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:% AC 5SMB MAMB3 100D CF(2)where:AC = measured asphalt content percent by
46、mass of theoven-dry HMA sample,MA= total mass of aggregate remaining after ignition,MB= total mass of the HMA sample prior to ignition, andCF= calibration factor obtained in Section 9 and enteredinto the furnaces data collection system.TEST METHOD B11. Apparatus11.1 In addition to the apparatus list
47、ed 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 expedite the test and to reduce escape ofsmoke into the laboratory. The furnace chamber shall be o
48、fsufficient 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
49、 into thelaboratory. The furnace shall be equipped so that the doorcannot be opened during the ignition test.11.1.2 Filters, if required, of the type specified by thefurnace manufacturer.12. Calibration12.1 The results of this test method may be affected by thetype of aggregate in the mixture because different aggregateslose mass on ignition to varying degrees. The results also maybe affected by the presence of additives and modifiers in theHMA sample. Accordingly, to optimize accuracy, a calibrationfactor shall be established by testing three calibration
