1、Designation: D2726/D2726M 17Standard Test Method forBulk Specific Gravity and Density of Non-AbsorptiveCompacted Asphalt Mixtures1This standard is issued under the fixed designation D2726/D2726M; the number immediately following the designation indicates theyear of original adoption or, in the case
2、of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This t
3、est method covers the determination of bulkspecific gravity and density of specimens of compacted asphaltmixtures.1.2 This test method should not be used with samples thatcontain open or interconnecting voids or absorb more than 2 %of water by volume, or both, as determined in 11.3.1.3 The values st
4、ated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4
5、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.1.5 This internatio
6、nal standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Commit
7、tee.2. Referenced Documents2.1 ASTM Standards:2D979 Practice for Sampling Bituminous Paving MixturesD1188 Test Method for Bulk Specific Gravity and Density ofCompacted Bituminous Mixtures Using Coated SamplesD3203 Test Method for Percent Air Voids in CompactedDense and Open Bituminous Paving Mixture
8、sD3666 Specification for Minimum Requirements for Agen-cies Testing and Inspecting Road and Paving MaterialsD4753 Guide for Evaluating, Selecting, and Specifying Bal-ances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD5361 Practice for Sampling Compacted Bituminous Mix
9、-tures for Laboratory TestingD6752 Test Method for Bulk Specific Gravity and Densityof Compacted Bituminous Mixtures Using AutomaticVacuum Sealing MethodD7227 Practice for Rapid Drying of Compacted AsphaltSpecimens Using Vacuum Drying ApparatusE1 Specification for ASTM Liquid-in-Glass ThermometersE7
10、7 Test Method for Inspection and Verification of Ther-mometersE563 Practice for Preparation and Use of an Ice-Point Bathas a Reference TemperatureE644 Test Methods for Testing Industrial Resistance Ther-mometersE1137 Specification for Industrial Platinum Resistance Ther-mometersE2251 Specification f
11、or Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision Liquids3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 bulk densityas determined by this test method, themass of a metre cubed (or foot cubed) of the material at 25 C77 F.3.1.2 bulk specific gravityas determined b
12、y this testmethod, the ratio of the mass of a given volume of material at25 C 77 F to the mass of an equal volume of water at thesame temperature.4. Summary of Test Method4.1 The specimen is immersed in a water bath at 25 C77 F. The mass under water is recorded, and the specimen istaken out of the w
13、ater, blotted quickly with a damp cloth towel,1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.21 onSpecific Gravity and Density of Asphalt Mixtures.Current edition approved June 1, 2017. Published June
14、 2017. Originallyapproved in 1968. Last previous edition approved in 2014 as D2726/D2726M 14.DOI: 10.1520/D2726_D2726M-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, ref
15、er to the standards Document Summary page onthe ASTM website.*A 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 StatesThis international standard was developed in accordance with
16、internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1and weighed in air. The difference between
17、the two masses isused to measure the mass of an equal volume of water at 25 C77 F.4.2 This test method provides guidance for determination ofthe oven dry or thoroughly dry mass of the specimen. The bulkspecific gravity is calculated from these masses. Then thedensity is obtained by multiplying the s
18、pecific gravity of thespecimen by the density of the water.5. Significance and Use5.1 The results obtained from this test method can be usedto determine the unit weight of compacted dense asphaltmixtures and in conjunction with Test Method D3203, to obtainpercent air voids. These values in turn may
19、be used indetermining the relative degree of compaction.5.2 Since specific gravity has no units, it must be convertedto density in order to do calculations that require units. Thisconversion is made by multiplying the specific gravity at agiven temperature by the density of water at the same tempera
20、-ture.NOTE 1The quality of the results produced by this standard aredependent on the competence of the personnel performing the procedureand the capability, calibration, and maintenance of the equipment used.Agencies that meet the criteria of Specification D3666 are generallyconsidered capable of co
21、mpetent and objective testing, sampling,inspection, etc. Users of this standard are cautioned that compliance withSpecification D3666 alone does not completely ensure reliable results.Reliable results depend on many factors; following the suggestions ofSpecification D3666 or some similar acceptable
22、guideline provides ameans of evaluating and controlling some of those factors.6. Apparatus6.1 Balance, with ample capacity, and with sufficient sensi-tivity to enable bulk specific gravities of the specimens to becalculated to at least four significant figures, that is, to at leastthree decimal plac
23、es. It shall be equipped with a suitableapparatus to permit weighing the specimen while suspended inwater. To avoid erroneous readings by undue displacement ofwater, use wire or fish line of the smallest practical size tosuspend the specimen and holder. Do not use chains, strings, orsash cords. The
24、balance shall conform to Guide D4753 as aClass GP2 balance.NOTE 2Since there are no more significant figures in the quotient(bulk specific gravity) than appear in either the dividend (the mass of thespecimen in air) or in the divisor (the mass of the volume of water equalto the volume of the specime
25、n, obtained from the difference in weight ofthe saturated surface-dry specimen in air and in water), this means that thebalance must have a sensitivity capable of providing both mass values toat least four figures. For example, a sensitivity of 0.1 g 0.0002 lb wouldprovide four significant figures f
26、or mass in the range from 100.1 to 999.9 g0.221 to 2.204 lb.6.2 Water Bath, capable of maintaining a temperature of 256 1 C 77 6 1.8 F for immersing the specimen in waterwhile suspended, equipped with an overflow outlet for main-taining a constant water level. The use of an overflow outlet ismandato
27、ry.NOTE 3The water bath does not need to be a sophisticated device.Any method that maintains 25 6 1 C 77 6 1.8 F can be used includingtempering, aquarium heaters, stirrers, or other devices.6.3 Drying Oven, capable of maintaining a temperature of110 6 5 C 230 6 9 F.6.4 ThermometerThe thermometer sha
28、ll be one of thefollowing:6.4.1 A liquid-in-glass partial immersion thermometer ofsuitable range with subdivisions and maximum scale error of0.5 C 1.0 F which conforms to the requirements of Speci-fication E1. Calibrate the thermometer in accordance with oneof the methods in Test Method E77 or verif
29、y its originalcalibration at the ice point (Note 4 and Note 5).NOTE 4Practice E563 provides instructions on the preparation and useof an ice-point bath as a reference temperature.NOTE 5If the thermometer does not read 0.0 6 0.5 C 32.0 6 1.0 Fat the ice point then the thermometer should be recalibrat
30、ed.6.4.2 A liquid-in-glass partial immersion thermometer ofsuitable range with subdivisions and maximum scale error of0.5 C 1.0 F which conforms to the requirements of Speci-fication E2251. Calibrate the thermometer in accordance withone the methods in Test Method E77 or verify its originalcalibrati
31、on at the ice point (Note 4 and Note 5).6.4.3 Aplatinum resistance thermometer (PRT) with a probewhich conforms to the requirements of Specification E1137.The PRT shall have a 3- or 4-wire connection configuration andthe overall sheath length shall be at least 50 mm (2 in.) greaterthan the immersion
32、 depth. Calibrate the PRT system (probe andreadout) in accordance with Test Methods E644 or verify itsoriginal calibration at the ice point (Note 4 and Note 5).Corrections shall be applied to ensure accurate measurementswithin 0.5 C 1.0 F.6.4.4 A metal-sheathed thermistor with a sensor substan-tiall
33、y similar in construction to the PRT probe described in6.4.3. Calibrate the thermistor system (sensor and readout) inaccordance with Test Methods E644 or verify its originalcalibration at the ice point (Note 4 and Note 5). Correctionsshall be applied to ensure accurate measurements within 0.5 C1.0 F
34、.7. Standardization7.1 BalanceStandardize at least once each twelve months.7.2 Temperature-Measuring DevicesStandardize at leastonce every twelve months.7.3 Drying OvenStandardize thermometric devices atleast once every twelve months.NOTE 6The terms of standardization, verification, calibration, and
35、check are defined in Specification D3666 Section 3.8. Sampling8.1 Specimens may be either laboratory-molded asphaltmixtures or from asphalt pavements.8.2 Obtain field samples in accordance with Practice D979.8.3 Pavement specimens shall be taken from pavementswith a core drill, diamond or carborundu
36、m saw, or by othersuitable means, in accordance with Practice D5361.9. Test Specimens9.1 Size of SpecimensIt is recommended (1) that thediameter of cyclindrically molded or cored specimens, or theD2726/D2726M 172length of the sides of sawed specimens, be at least equal to fourtimes the maximum size
37、of the aggregate; and (2) that thethickness of specimens be at least one and one-half times themaximum size of the aggregate.9.2 Care shall be taken to avoid distortion, bending, orcracking of specimens during and after removal from pave-ments or mold. Specimens shall be stored in a safe, cool place
38、.9.3 Specimens shall be free of foreign materials such as sealcoat, tack coat, foundation material, soil, paper, or foil. Whenany of these materials is visually evident, it shall be removedby sawing. Wire brushing to remove paper, soil, and foil isacceptable if all traces of the materials are elimin
39、ated.9.4 If desired, specimens may be separated from otherpavement layers by sawing or other satisfactory means.10. Procedure10.1 For Cores and for Other Specimens that May ContainMoisture or SolventOnly specimens that are known to bethoroughly dry (that is, laboratory-prepared dried specimens),are
40、to be tested in accordance with 10.2.All others are assumedto contain moisture or solvent and are to be tested in accor-dance with 10.1. The sequence of testing for 10.1 is: in water,saturated surface-dry, dry.10.1.1 Mass of Specimen in WaterCompletely submergethe specimen in the water bath at 25 6
41、1 C 77 6 1.8 F for3 to 5 min then determine the mass by weighing in water.Designate this mass as C. If the temperature of the specimendiffers from the temperature of the water bath by more than2 C 3.6 F, the specimen shall be immersed in the water bathfor 10 to 15 min, instead of 3 to 5 min.10.1.2 M
42、ass of Saturated Surface-Dry Specimen in AirWithin 15 s of removing the sample from the water bath,surface dry the specimen by blotting quickly with a damp clothtowel and then determine the mass by weighing in air.Designate this mass as B.10.1.3 After determining the mass in water and in a satu-rate
43、d surface-dry condition, thoroughly dry the specimen to aconstant mass at 110 6 5 C 230 6 9 F.Allow the specimento cool and weigh in air. Designate this mass as A. Othermethods may be used to dry the specimen as long as a constantmass is achieved (mass repeats within 0.1 %).NOTE 7Drying the specimen
44、 at the required temperature of 110 C230 F will change the characteristics and shape of the specimen. Thiswill make the specimen unsuitable for further testing. Drying thespecimen at a reduced temperature such as 52 C 125 F, in order tokeep it intact, will not meet the requirements of this test meth
45、od.10.1.3.1 Practice D7227, microwave drying, or other ap-proved methods may be used to dry the specimen if thespecimen is not overheated and documentation exists showingthat the results are equivalent to oven drying. The interval oftime between readings to determine constant mass must besufficient
46、to ensure that all moisture and solvent has beenremoved. This interval is dependent on the size of the specimenand can be determined by experimentation and confirmed withthe oven-dried comparisons. Documentation must exist tovalidate the intervals.10.2 For Laboratory-Prepared Thoroughly Dry Specimen
47、s:10.2.1 Mass of Dry Specimen in AirDetermine the massby weighing the specimen after it has been standing in air atroom temperature for at least 1 h. Designate this mass as A.10.2.2 Mass of Specimen in WaterUse the same procedureas described in 10.1.1.10.2.3 Mass of Saturated Surface-Dry Specimen in
48、 AirSurface dry the specimen by blotting quickly with a damp clothtowel and then determine the mass by weighing in air.Designate this mass as B.11. Calculation11.1 Calculate the bulk specific gravity of the specimen asfollows:Bulk sp gr 5 A/B 2 C! (1)where:A = mass of the dry specimen in air, g lb,(
49、BC) = mass of the volume of water for the volume of thespecimen at 25 C 77 F,B = mass of the saturated surface-dry specimen in air,g lb, andC = mass of the specimen in water, g lb.11.2 Calculate the density of the specimen as follows:Density 5 Bulk sp gr 3997.0 or 62.24! (2)where:997.0 (0.997 g/cm3) = density of water in kg/m3at 25 C77 F.11.3 Calculate the percent water absorbed by the specimen(on volume basis) as follows:Percent water absorbed by volume 5B 2 AB 2 C
