1、Designation: D2726/D2726M 13D2726/D2726M 14Standard Test Method forBulk Specific Gravity and Density of Non-AbsorptiveCompacted Bituminous Mixtures1This standard is issued under the fixed designation D2726/D2726M; the number immediately following the designation indicates theyear of original adoptio
2、n 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 Defense.1
3、. Scope*1.1 This test method covers the determination of bulk specific gravity and density of specimens of compacted bituminousmixtures.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 determined in
4、 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 in non-conforma
5、nce 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 regulatorylimitations prior to
6、 use.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 Dense and Open Bituminous Paving Mixt
7、uresD3666 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 for Sampling Compacted Bituminous Mi
8、xtures 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 ASTM Liquid-in-Glass Thermometers
9、E77 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 ThermometersE2251 Specification f
10、or Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 bulk densityas determined by this test method, the mass of a metre cubed (or foot cubed) of the material at 25C 77F.1 This test method is under the jurisdictio
11、n of ASTM Committee D04 on Road and Paving Materials and is the direct responsibility of Subcommittee D04.21 on SpecificGravity and Density of BituminousAsphalt Mixtures.Current edition approved July 1, 2013Aug. 1, 2014. Published August 2013August 2014. Originally approved in 1968. Last previous ed
12、ition approved in 20112013 asD2726 11.D2726/D2726M 13. DOI: 10.1520/D2726_D2726M-13.10.1520/D2726_D2726M-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the stand
13、ards 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 indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accuratel
14、y, 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 considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Driv
15、e, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.2 bulk specific gravityas determined by this test method, the ratio of the mass of a given volume of material at 25C 77Fto the mass of an equal volume of water at the same temperature.4. Summary of Test Method4.1 The specimen is imm
16、ersed in a water bath at 25C 77F. The mass under water is recorded, and the specimen is taken outof the water, blotted quickly with a damp cloth towel, and weighed in air.The difference between the two masses is used to measurethe mass of an equal volume of water at 25C 77F.4.2 This test method prov
17、ides 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 density of the water.5. Significance and Use5.1 The results obtaine
18、d from this test method can be used to determine the unit weight of compacted dense bituminous mixturesand in conjunction with Test Method D3203, to obtain percent air voids. These values in turn may be used in determining therelative degree of compaction.5.2 Since specific gravity has no units, it
19、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 and equipment used in performing this test can be evaluated in accordance
20、 with Practice D3666.6. Apparatus6.1 Balance, with ample capacity, and with sufficient sensitivity to enable bulk specific gravities of the specimens to becalculated to at least four significant figures, that is, to at least three decimal places. It shall be equipped with a suitable apparatusto perm
21、it 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 suspend the specimen and holder. Do not use chains, strings, or sash cords. The balanceshall conform to Guide D4753 as a Class GP2 bal
22、ance.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 in the divisor (the mass of the volume of water equal to the volume of the specimen, obtained from the difference in weight of the sat
23、uratedsurface-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 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 0.221 t
24、o 2.204 lb.6.2 Water Bath, capable of maintaining a temperature of 25 6 1C 77 6 1.8F for immersing the specimen in water whilesuspended, equipped with an overflow outlet for maintaining a constant water level. The use of an overflow outlet is mandatory.NOTE 3The water bath does not need to be a soph
25、isticated device. Any method that maintains 25 6 1C 77 6 1.8F can be used includingtempering, aquarium heaters, stirrers, or other devices.6.3 Drying Oven, capable of maintaining a temperature of 110 6 5C 230 6 9F.6.4 Temperature Measuring Device, ThermometerThermometers of suitable range with subdi
26、visions and maximum scaleerror of 0.5C 1.0F, or any other thermometric device of equal accuracy, precision, and sensitivity shall be used. Thermometersshall conform to the requirements of SpecificationThe thermometer shall be one of the E1.following:6.4.1 A liquid-in-glass partial immersion thermome
27、ter of suitable range with subdivisions and maximum scale error of 0.5C1.0F which conforms to the requirements of Specification E1. Calibrate the thermometer in accordance with one of the methodsin Test Method E77 or verify its original calibration at the ice point (Note 4 and Note 5).NOTE 4Practice
28、 E563 provides instructions on the preparation and use of an ice-point bath as a reference temperature.NOTE 5If the thermometer does not read 0.0 6 0.5C 32.0 6 1.0F at the ice point then the thermometer should be recalibrated.6.4.2 A liquid-in-glass partial immersion thermometer of suitable range wi
29、th subdivisions and maximum scale error of 0.5C1.0F which conforms to the requirements of Specification E2251. Calibrate the thermometer is accordance with one the methodsin Test Method E77 or verify its original calibration at the ice point (Note 4 and Note 5).6.4.3 A platinum resistance thermomete
30、r (PRT) with a probe which conforms to the requirements of Specification E1137. ThePRT shall have a 3- or 4-wire connection configuration and the overall sheath length shall be at least 50 mm (2 in.) greater thanthe immersion depth. Calibrate the PRT system (probe and readout) in accordance with Tes
31、t Methods E644 or verify its originalcalibration at the ice point (Note 4 and Note 5). Corrections shall be applied to ensure accurate measurements within 0.5C 1.0F.6.4.4 A metal-sheathed thermistor with a sensor substantially-similar in construction to the PRT probe described in 6.4.3.Calibrate the
32、 thermistor system (sensor and readout) in accordance with Test Methods E644 or verify its original calibration at theice point (Note 4 and Note 5). Corrections shall be applied to ensure accurate measurements within 0.5C 1.0F.7. Standardization7.1 Balance, Standardize at least once each 12 months7.
33、2 Temperature measuring devices, standardize at least once every 12 months.D2726/D2726M 1427.3 Drying Oven, standardize thermometric devices at least once every 12 months.NOTE 6The terms of standardization, verification, calibration, check, are defined in D3666 Section 3.8. Sampling8.1 Specimens may
34、 be either laboratory-molded bituminous mixtures or from bituminous pavements.8.2 Obtain field samples in accordance with Practice D979.8.3 Pavement specimens shall be taken from pavements with a core drill, diamond or a carborundum saw, or by other suitablemeans, in accordance with Practice D5361.9
35、. 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 maximum size of the aggregate; and (2) that the thickness ofspecimens be at least one and one ha
36、lf 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 safe, cool place.9.3 Specimens shall be free of foreign materials such as seal coat, tack coat, fou
37、ndation material, soil, paper, or foil. When anyof these materials are visually evident, they shall be removed by sawing. Wire brushing to remove paper, soil, and foil is acceptableif all traces of the materials are eliminated.9.4 If desired, specimens may be separated from other pavement layers by
38、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-prepared dried specimens), are to be tested in accordance with 10.2. All others are assumed tocontain mois
39、ture 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, dry.10.1.1 Mass of Specimen in WaterCompletely submerge the specimen in the water bath at 25 6 1C 77 6 1.8F for 3 to5 min then determine the mass by weighing in water. D
40、esignate this mass as C. If the temperature of the specimen differs fromthe temperature of the water bath by more than 2C 3.6F, the specimen shall be immersed in the water bath for 10 to 15 min,instead of 3 to 5 min.10.1.2 Mass of Saturated Surface-Dry Specimen in AirSurface dry the specimen by blot
41、ting quickly with a damp cloth toweland 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 saturated-surface dry condition, thoroughly dry the specimen to a constantmass at 110 6 5C 230 6 9F. Allow the specimen to cool and weigh i
42、n air. Designate this mass as A. Other methods may beused to dry the specimen as long as a constant mass is achieved (mass repeats within 0.1 %).NOTE 7Drying the specimen at the required temperature of 110C 230F will change the characteristics and shape of the specimen. This will makethe specimen un
43、suitable for further testing. Drying the specimen at a reduced temperature such as 52C 125F, in order to keep it intact, will not meetthe 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-he
44、ated and documentation exists showing that the results are equivalent to oven drying. The interval of time between readingsto determine constant mass must be sufficient to ensure that all moisture and solvent has been removed. This interval is dependenton the size of the specimen and can be determin
45、ed by experimentation and confirmed with the oven-dried comparisons.Documentation must exist to validate the intervals.10.2 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 roomtemperat
46、ure 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 Saturated Surface-Dry Specimen in AirSurface dry the specimen by blotting quickly with a damp cloth toweland then determine the mass by weighing in air. Designa
47、te this mass as B.11. Calculation11.1 Calculate the bulk specific gravity of the specimen as follows:Bulk sp gr5A/B 2C! (1)where:A = mass of the dry specimen in air, g lb;D2726/D2726M 143(B C) = mass of the volume of water for the volume of the specimen at 25C 77F;B = mass of the saturated surface-d
48、ry specimen in air, g lb; andC = mass of the specimen in water, g lb.11.2 Calculate the density of the specimen as follows:Density5Bulk sp gr3997.0 or 62.24! (2)where:997.0 (0.997 g/cm3) = density of water in kg/m3 at 25C 77F11.3 Calculate the percent water absorbed by the specimen (on volume basis)
49、 as follows:Percent water absorbed by volume5B 2AB 2C 3100 (3)11.4 If the percent water absorbed by the specimen in 11.3 exceeds 2 %, use Test Method D1188 or Test Method D6752.11.5 This test method has been written expressing density in kilograms per cubic metre. Conversion to express the density inpounds per cubic foot is acceptable.12. Report12.1 Report the following:12.1.1 Bulk specific gravity of the mixture to the third decimal place as: bulk specific gravity at
