1、Designation: D2726 11Standard Test Method forBulk Specific Gravity and Density of Non-AbsorptiveCompacted Bituminous Mixtures1This standard is issued under the fixed designation D2726; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test method cover
3、s the determination of bulkspecific gravity and density of specimens of compacted bitu-minous mixtures.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 stated in SI
4、units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 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
5、practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D979 Practice for Sampling Bituminous Paving MixturesD1188 Test Method for Bulk Specific Gravity and Densityof Compacted Bituminous Mixtures Using CoatedSamplesD3203 Test Meth
6、od for Percent Air Voids in CompactedDense and Open Bituminous Paving MixturesD3666 Specification for Minimum Requirements for Agen-cies Testing and Inspecting Road and Paving MaterialsD4753 Guide for Evaluating, Selecting, and SpecifyingBalances and Standard Masses for Use in Soil, Rock, andConstru
7、ction Materials TestingD5361 Practice for Sampling Compacted Bituminous Mix-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 Vacu
8、um Drying ApparatusE1 Specification for ASTM Liquid-in-Glass Thermometers3. 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 25C(77F).3.1.2 bulk specific gravityas determined
9、 by this testmethod, the ratio of the mass of a given volume of material at25C to the mass of an equal volume of water at the sametemperature.4. Summary of Test Method4.1 The specimen is immersed in a water bath at 25C(77F). The mass under water is recorded, and the specimen istaken out of the water
10、, blotted quickly with a damp cloth towel,and weighed in air. The difference between the two masses isused to measure the mass of an equal volume of water at 25C.4.2 This test method provides guidance for determination ofthe oven dry or thoroughly dry mass of the specimen. The bulkspecific gravity i
11、s calculated from these masses. Then thedensity is obtained by multiplying the specific 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 bituminousmixtures and in conjun
12、ction with Test Method D3203, to obtainpercent air voids. These values in turn may 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
13、 specific gravity at agiven temperature by the density of water at the same tempera-ture.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 Bituminous Mixtures.Current
14、 edition approved Dec. 1, 2011. Published December 2011. Originallyapproved in 1968. Last previous edition approved in 2010 as D2726 10. DOI:10.1520/D2726-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of A
15、STMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 1The personnel an
16、d equipment used in performing this test canbe evaluated in accordance with Practice D3666.6. 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
17、 decimal places. 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, orsas
18、h cords. The 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 o
19、f the specimen, 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 would provide foursignificant figure
20、s for mass in the range from 100.1 to 999.9 g.6.2 Water Bath, capable of maintaining a temperature of 256 1C (77 6 1.8F) for immersing the specimen in water whilesuspended, equipped with an overflow outlet for maintaining aconstant water level. The use of an overflow outlet is manda-tory.NOTE 3The w
21、ater bath does not need to be a sophisticated device.Any method that maintains 25C 6 1C can be used including tempering,aquarium heaters, stirrers, or other devices.6.3 Drying Oven, capable of maintaining a temperature of110 +/- 5C (230 +/- 9F).6.4 Temperature Measuring Device, Thermometers of suit-
22、able range with subdivisions and maximum scale error of0.5C (1.0F), or any other thermometric device of equalaccuracy, precision, and sensitivity shall be used. Thermom-eters shall conform to the requirements of Specification E1.7. Standardization7.1 Balance, Standardize at least once each 12 months
23、7.2 Temperature measuring devices, standardize at leastonce every 12 months.7.3 Drying Oven, standardize thermometric devices at leastonce every 12 months.NOTE 4The terms of standardization, verification, calibration, check,are defined in D3666 Section 3.8. Sampling8.1 Specimens may be either labora
24、tory-molded bituminousmixtures or from bituminous 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 a carborundum saw, or by othersuitable means, in accordance with Practice D5361.9. Test Specimens9.1
25、 Size of SpecimensIt is recommended (1) that thediameter of cyclindrically molded or cored specimens, or thelength of the sides of sawed specimens, be at least equal to fourtimes the maximum size of the aggregate; and (2) that thethickness of specimens be at least one and one half times themaximum s
26、ize 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.9.3 Specimens shall be free of foreign materials such as sealcoat, tack coat, foundation material, soil
27、, paper, or foil. Whenany of these materials are visually evident, they shall beremoved by sawing. Wire brushing to remove paper, soil, andfoil is acceptable if all traces of the materials are eliminated.9.4 If desired, specimens may be separated from otherpavement layers by sawing or other satisfac
28、tory 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 to be tested in accordance with 10.2.All others are assumedto contain moisture or solvent and are to
29、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 1C (77 6 1.8F) for3 to 5 min then determine the mass by weighing in water.Designate this mass as C. I
30、f the temperature of the specimendiffers from the temperature of the water bath by more than2C (3.6F), the specimen shall be immersed 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 dry the specimen by blotting quickly with a damp
31、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 asaturated-surface dry condition, thoroughly dry the specimento a constant mass at 110 6 5C (230 6 9F). Allow thespecimen to cool and weigh in air. Designate this mass
32、 as A.Other methods may be used to dry the specimen as long as aconstant mass is achieved (mass repeats within 0.1 %).NOTE 5Drying the specimen at the required temperature of 110C(230F) will change the characteristics and shape of the specimen. Thiswill make the specimen unsuitable for further testi
33、ng. Drying thespecimen at a reduced temperature such as 52C (125F), in order to keepit intact, will not meet the requirements of this test method.10.1.3.1 Practice D7227, microwave drying or other ap-proved methods may be used to dry the specimen if thespecimen is not over-heated and documentation e
34、xists showingthat the results are equivalent to oven drying. The interval oftime between readings to determine constant mass must besufficient 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 c
35、onfirmed withthe oven-dried comparisons. Documentation must exist tovalidate the intervals.10.2 For Laboratory-Prepared Thoroughly Dry Specimens: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. Designa
36、te this mass as A.D2726 11210.2.2 Mass of Specimen in WaterUse the same procedureas described in 10.1.1.10.2.3 Mass of Saturated Surface-Dry Specimen in 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.
37、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;(BC) = mass of the volume of water for the volume ofthe specimen at 25C;B = mass of the saturated surface-dry specimen in air,g; andC = mass of the spec
38、imen in water, g.11.2 Calculate the density of the specimen as follows:Density 5 Bulk sp gr 3 997.0 or 62.24! (2)where:997.0 = density of water in kg/m3at 25C (0.9970 g/cm3)11.3 Calculate the percent water absorbed by the specimen(on volume basis) as follows:Percent water absorbed by volume 5B 2 AB
39、2 C3 100 (3)11.4 If the percent water absorbed by the specimen in 11.3exceeds 2 %, use Test Method D1188 or Test Method D6752.11.5 This test method has been written expressing density inkilograms per cubic metre. Conversion to express the densityin pounds per cubic foot is acceptable.12. Report12.1
40、Report the following:12.1.1 Bulk specific gravity of the mixture to the thirddecimal place as: bulk specific gravity at 25C,12.1.2 Density of the mixture with four significant figures inkg/m3or lb/ft3as: density at 25C,12.1.3 Type of mixture,12.1.4 Size of sample, and12.1.5 Water absorption, %.13. P
41、recision and Bias13.1 Precision:13.1.1 Single Operator PrecisionThe single operatorstandard deviations (1s limits) for specimens prepared inaccordance with 10.2, for mixtures containing aggregate withabsorption of less than 1.5 %, are shown in Table 1. The resultsof two properly conducted tests on t
42、he same material, by thesame operator, using the same equipment, should be consid-ered suspect if they differ by more than the d2s single operatorlimits shown in Table 1.13.1.2 Multilaboratory PrecisionThe multilaboratorystandard deviations (1s limits) for specimens prepared inaccordance with 10.2,
43、for mixtures containing aggregate withabsorption of less than 1.5 %, are shown in Table 1. The resultsof two properly conducted tests on the same material, bydifferent operators, using different equipment, should be con-sidered suspect if they differ by more than d2s multilaboratorylimits shown in T
44、able 1.13.2 BiasNo information can be presented on the bias ofthe procedure because no material having an accepted refer-ence value is available.14. Keywords14.1 air voids; compaction; density; specific gravity; unitweightSUMMARY OF CHANGESCommittee D04 has identified the location of selected change
45、s to this standard since the last issue(D2726 10) that may impact the use of this standard. (Approved June 1, 2010.)(1) Added oven and temperature measured device.(2) Added new Section 7 on Standardizationand new Note 4(3) Renumbered existing sections.Committee D04 has identified the location of sel
46、ected changes to this standard since the last issue(D2726 08) that may impact the use of this standard. (Approved June 1, 2009.)(1) Added new Section 6.3.(2) Revised Section 9.3.TABLE 1 Precision EstimatesA1s limit d2s limitSingle Operator Precision:12.5-mm nominal max agg. 0.008 0.02319.0-mm nomina
47、l max agg. 0.013 0.037Multilaboratory Precision:12.5-mm nominal max agg. 0.015 0.04219.0-mm nominal max agg. 0.015 0.042ABased on an interlaboratory study conducted under NCHRP Project 9-26involving 150-mm diameter specimens with 4.5 % air voids, 26 laboratories, twomaterials (a 12.5-mm mixture and
48、a 19.0-mm mixture), and three replicates.The precision statement in 13.1 was derived from data resulting from laborato-ries that compacted samples sent out by the AMRL.D2726 113ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item ment
49、ionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headqua
