1、Designation: D2726/D2726M 14D2726/D2726M 17Standard Test Method forBulk Specific Gravity and Density of Non-AbsorptiveCompacted BituminousAsphalt Mixtures1This standard is issued under the fixed designation D2726/D2726M; the number immediately following the designation indicates theyear of original
2、adoption or, in the case 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 De
3、fense.1. Scope*1.1 This test method covers the determination of bulk specific gravity and density of specimens of compacted bituminousasphaltmixtures.1.2 This test method should not be used with samples that contain open or interconnecting voids or absorb more than 2 % ofwater by volume, or both, as
4、 determined in 11.3.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result i
5、n non-conformance with the standard.1.4 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 and health practices and determine the applicability of regulatorylimita
6、tions prior to use.1.5 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 Organization Techn
7、ical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D979 Practice for Sampling Bituminous Paving MixturesD1188 Test Method for Bulk Specific Gravity and Density of Compacted Bituminous Mixtures Using Coated SamplesD3203 Test Method for Percent Air Voids in Compacted Den
8、se and Open Bituminous Paving MixturesD3666 Specification for Minimum Requirements for Agencies Testing and Inspecting Road and Paving MaterialsD4753 Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and ConstructionMaterials TestingD5361 Practice fo
9、r Sampling Compacted Bituminous Mixtures for Laboratory TestingD6752 Test Method for Bulk Specific Gravity and Density of Compacted Bituminous Mixtures Using Automatic VacuumSealing MethodD7227 Practice for Rapid Drying of Compacted Asphalt Specimens Using Vacuum Drying ApparatusE1 Specification for
10、 ASTM Liquid-in-Glass ThermometersE77 Test Method for Inspection and Verification of ThermometersE563 Practice for Preparation and Use of an Ice-Point Bath as a Reference TemperatureE644 Test Methods for Testing Industrial Resistance ThermometersE1137 Specification for Industrial Platinum Resistance
11、 ThermometersE2251 Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids1 This test method is under the jurisdiction of ASTM Committee D04 on Road and Paving Materials and is the direct responsibility of Subcommittee D04.21 on SpecificGravity and Density of Asphalt Mi
12、xtures.Current edition approved Aug. 1, 2014June 1, 2017. Published August 2014June 2017. Originally approved in 1968. Last previous edition approved in 20132014 asD2726/D2726M 13.D2726/D2726M 14. DOI: 10.1520/D2726_D2726M-14.10.1520/D2726_D2726M-17.2 For referencedASTM standards, visit theASTM webs
13、ite, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indicatio
14、n of what changes have been made 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 consid
15、ered the official document.*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 States13. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 bulk densityas determin
16、ed by this test method, the mass of a metre cubed (or foot cubed) of the material at 25C77F.25 C 77 F.3.1.2 bulk specific gravityas determined by this test method, the ratio of the mass of a given volume of material at 25C77F25 C 77 F to the mass of an equal volume of water at the same temperature.4
17、. Summary of Test Method4.1 The specimen is immersed in a water bath at 25C 77F.25 C 77 F.The mass under water is recorded, and the specimenis taken out of the water, blotted quickly with a damp cloth towel, and weighed in air. The difference between the two masses isused to measure the mass of an e
18、qual volume of water at 25C 77F.25 C 77 F.4.2 This test method provides guidance for determination of the oven dry or thoroughly dry mass of the specimen. The bulkspecific gravity is calculated from these masses. Then the density is obtained by multiplying the specific gravity of the specimenby the
19、density of the water.5. Significance and Use5.1 The results obtained from this test method can be used to determine the unit weight of compacted dense bituminousasphaltmixtures and in conjunction with Test Method D3203, to obtain percent air voids. These values in turn may be used in determiningthe
20、relative degree of compaction.5.2 Since specific gravity has no units, it must be converted to density in order to do calculations that require units. Thisconversion is made by multiplying the specific gravity at a given temperature by the density of water at the same temperature.NOTE 1The personnel
21、 and equipment used in performing this test can be evaluated inquality of the results produced by this standard are dependenton the competence of the personnel performing the procedure and the capability, calibration, and maintenance of the equipment used.Agencies that meetthe criteria of Specificat
22、ion D3666 accordance with Practice are generally considered capable of competent and objective testing, sampling, inspection,etc. Users of this standard are cautioned that compliance with Specification D3666. alone does not completely ensure reliable results. Reliable resultsdepend on many factors;
23、following the suggestions of Specification D3666 or some similar acceptable guideline provides a means of evaluating andcontrolling some of those factors.6. Apparatus6.1 Balance, with ample capacity, and with sufficient sensitivity to enable bulk specific gravities of the specimens to becalculated t
24、o at least four significant figures, that is, to at least three decimal places. It shall be equipped with a suitable apparatusto permit weighing the specimen while suspended in water. To avoid erroneous readings by undue displacement of water, use wireor fish line of the smallest practical size to s
25、uspend the specimen and holder. Do not use chains, strings, or sash cords. The balanceshall conform to Guide D4753 as a Class 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 the specimenin air) or i
26、n the divisor (the mass of the volume of water equal to the volume of the specimen, obtained from the difference in weight of the saturatedsurface-dry specimen in air and in water), this means that the balance must have a sensitivity capable of providing both mass values to at least four figures.For
27、 example, a sensitivity of 0.1 g 0.0002 lb would provide four significant figures for mass in the range from 100.1 to 999.9 g 999.9 g 0.221 to 2.204lb.6.2 Water Bath, capable of maintaining a temperature of 25 6 1C1 C 77 6 1.8F1.8 F for immersing the specimen inwater while suspended, equipped with a
28、n overflow outlet for maintaining a constant water level. The use of an overflow outlet ismandatory.NOTE 3The water bath does not need to be a sophisticated device. Any method that maintains 25 6 1C1 C 77 6 1.8F1.8 F can be usedincluding tempering, aquarium heaters, stirrers, or other devices.6.3 Dr
29、ying Oven, capable of maintaining a temperature of 110 6 5C5 C 230 6 9F.9 F.6.4 ThermometerThe thermometer shall be one of the following:6.4.1 A liquid-in-glass partial immersion thermometer of suitable range with subdivisions and maximum scale error of 0.5C1.0F0.5 C 1.0 F which conforms to the requ
30、irements of Specification E1. Calibrate the thermometer in accordance with oneof the methods in Test Method E77 or verify its original calibration at the ice point (Note 4 and Note 5).NOTE 4Practice E563 provides instructions on the preparation and use of an ice-point bath as a reference temperature
31、.NOTE 5If the thermometer does not read 0.0 6 0.5C0.5 C 32.0 6 1.0F1.0 F at the ice point then the thermometer should be recalibrated.6.4.2 A liquid-in-glass partial immersion thermometer of suitable range with subdivisions and maximum scale error of 0.5C1.0F0.5 C 1.0 F which conforms to the require
32、ments of Specification E2251. Calibrate the thermometer isin accordance withone the methods in Test Method E77 or verify its original calibration at the ice point (Note 4 and Note 5).6.4.3 A platinum resistance thermometer (PRT) with a probe which conforms to the requirements of Specification E1137.
33、 ThePRT shall have a 3- or 4-wire connection configuration and the overall sheath length shall be at least 50 mm (2 in.) greater thanD2726/D2726M 172the immersion depth. Calibrate the PRT system (probe and readout) in accordance with Test Methods E644 or verify its originalcalibration at the ice poi
34、nt (Note 4 and Note 5). Corrections shall be applied to ensure accurate measurements within 0.5C1.0F.0.5 C 1.0 F.6.4.4 A metal-sheathed thermistor with a sensor substantially-similar substantially similar in construction to the PRT probedescribed in 6.4.3. Calibrate the thermistor system (sensor and
35、 readout) in accordance with Test Methods E644 or verify its originalcalibration at the ice point (Note 4 and Note 5). Corrections shall be applied to ensure accurate measurements within 0.5C1.0F.0.5 C 1.0 F.7. Standardization7.1 Balance, BalanceStandardize at least once each 12 monthstwelve months.
36、7.2 Temperature measuring devices, Temperature-Measuring DevicesstandardizeStandardize at least once every 12twelvemonths.7.3 Drying Oven, OvenstandardizeStandardize thermometric devices at least once every 12twelve months.NOTE 6The terms of standardization, verification, calibration, check, and che
37、ck are defined in Specification D3666 Section 3.8. Sampling8.1 Specimens may be either laboratory-molded bituminousasphalt mixtures or from bituminousasphalt pavements.8.2 Obtain field samples in accordance with Practice D979.8.3 Pavement specimens shall be taken from pavements with a core drill, di
38、amond or a carborundum saw, or by other suitablemeans, in accordance with Practice D5361.9. Test Specimens9.1 Size of SpecimensIt is recommended (1) that the diameter of cyclindrically molded or cored specimens, or the length ofthe sides of sawed specimens, be at least equal to four times the maximu
39、m size of the aggregate; and (2) that the thickness ofspecimens be at least one and one half one-half times the maximum size of the aggregate.9.2 Care shall be taken to avoid distortion, bending, or cracking of specimens during and after removal from pavements or mold.Specimens shall be stored in a
40、safe, cool place.9.3 Specimens shall be free of foreign materials such as seal coat, tack coat, foundation material, soil, paper, or foil. When anyof these materials areis visually evident, theyit shall be removed by sawing. Wire brushing to remove paper, soil, and foil isacceptable if all traces of
41、 the materials are eliminated.9.4 If desired, specimens may be separated from other pavement layers by sawing or other satisfactory means.10. Procedure10.1 For Cores and for Other Specimens that May Contain Moisture or SolventOnly specimens that are known to bethoroughly dry (that is, laboratory-pre
42、pared dried specimens), are to be tested in accordance with 10.2. All others are assumed tocontain moisture or solvent and are to be tested in accordance with 10.1. The sequence of testing for 10.1 is: in water,saturated-surface dry,saturated surface-dry, dry.10.1.1 Mass of Specimen in WaterComplete
43、ly submerge the specimen in the water bath at 25 6 1C1 C 77 6 1.8F1.8 Ffor 3 to 5 min then determine the mass by weighing in water. Designate this mass as C. If the temperature of the specimen differsfrom the temperature of the water bath by more than 2C 3.6F,2 C 3.6 F, the specimen shall be immerse
44、d in the water bathfor 10 to 15 min, instead of 3 to 5 min.10.1.2 Mass of Saturated Surface-Dry Specimen in AirSurface Within 15 s of removing the sample from the water bath,surface dry the specimen by blotting quickly with a damp cloth towel and then determine the mass by weighing in air. Designate
45、this mass as B.10.1.3 After determining the mass in water and in a saturated-surface drysaturated surface-dry condition, thoroughly dry thespecimen to a constant mass at 110 6 5C5 C 230 6 9F.9 F. Allow the specimen to cool and weigh in air. Designate thismass as A. Other methods may be used to dry t
46、he specimen as long as a constant mass is achieved (mass repeats within 0.1 %).NOTE 7Drying the specimen at the required temperature of 110C 230F110 C 230 F will change the characteristics and shape of the specimen.This will make the specimen unsuitable for further testing. Drying the specimen at a
47、reduced temperature such as 52C 125F,52 C 125 F, in orderto keep it intact, will not meet the requirements of this test method.10.1.3.1 Practice D7227, microwave drying, or other approved methods may be used to dry the specimen if the specimen is notover-heatedoverheated and documentation exists sho
48、wing that the results are equivalent to oven drying. The interval of timebetween readings to determine constant mass must be sufficient to ensure that all moisture and solvent has been removed. Thisinterval is dependent on the size of the specimen and can be determined by experimentation and confirm
49、ed with the oven-driedcomparisons. Documentation must exist to validate the intervals.D2726/D2726M 17310.2 For Laboratory-Prepared Thoroughly Dry Specimens:10.2.1 Mass of Dry Specimen in AirDetermine the mass by weighing the specimen after it has been standing in air at roomtemperature for at least 1 h. Designate this mass as A.10.2.2 Mass of Specimen in WaterUse the same procedure as described in 10.1.1.10.2.3 Mass of Saturat
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