1、Designation: D2726 11D2726/D2726M 13Standard Test Method forBulk Specific Gravity and Density of Non-AbsorptiveCompacted Bituminous Mixtures1This standard is issued under the fixed designation D2726;D2726/D2726M; the number immediately following the designation indicatesthe year of original adoption
2、 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 Department of Defense.1. Scop
3、e*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 11.3.
4、1.3 The values stated in either SI units or inch-pound units are to be regarded separately as the standard. The values given inparentheses are for information only.stated in each system may not be exact equivalents; therefore, each system shall be usedindependently of the other. Combining values fro
5、m the two systems may result in 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 app
6、licability of regulatorylimitations prior to 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 Com
7、pacted Dense 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 P
8、ractice for 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 Specifi
9、cation 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, the mass of a metre cubed (or foot cubed) of the material at 25C(77F).77F.3.1.2 bulk specific gravityas determined by this test method, th
10、e 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.1 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 D
11、ensity of Bituminous Mixtures.Current edition approved Dec. 1, 2011July 1, 2013. Published December 2011August 2013. Originally approved in 1968. Last previous edition approved in 20102011 asD2726 10.D2726 11. DOI: 10.1520/D2726-11.10.1520/D2726_D2726M-13.2 For referencedASTM standards, visit theAST
12、M website, 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 ind
13、ication 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
14、considered 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 States14. Summary of Test Method4.1 The specimen is immersed in a water bath at 25C (77F).77F.
15、The mass under water is recorded, and the specimen istaken out of the water, blotted quickly with a damp cloth towel, and weighed in air. The difference between the two masses is usedto measure the mass of an equal volume of water at 25C. 25C 77F.4.2 This test method provides guidance for determinat
16、ion 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 obtained from this test method can
17、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 must be converted to density
18、 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 with Practice D3666.6. Appa
19、ratus6.1 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 permit weighing the specimen whi
20、le 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 balance.NOTE 2Since there are n
21、o 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 saturatedsurface-dry specimen i
22、n 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.g 0.221 to 2.204 lb.6.2 Water Bath,
23、 capable of maintaining a temperature of 25 6 1C (7777 6 1.8F)1.8F for immersing the specimen in waterwhile suspended, equipped with an 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. A
24、ny method that maintains 25C25 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 +/- 5C (230 +/- 9F).6 5C 230 6 9F.6.4 Temperature Measuring Device, Thermometers of suitable range with subdivisions
25、 and maximum scale error of 0.5C(1.0F),1.0F, or any other thermometric device of equal accuracy, precision, and sensitivity shall be used. Thermometers shallconform to the requirements of Specification E1.7. Standardization7.1 Balance, Standardize at least once each 12 months7.2 Temperature measurin
26、g devices, standardize at least once every 12 months.7.3 Drying Oven, standardize thermometric devices at least once every 12 months.NOTE 4The terms of standardization, verification, calibration, check, are defined in D3666 Section 3.8. Sampling8.1 Specimens may be either laboratory-molded bituminou
27、s 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. Test Specimens9.1 Size of SpecimensI
28、t 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 half times the maximum size of the aggre
29、gate.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.D2726/D2726M 1329.3 Specimens shall be free of foreign materials such as seal coat, tack coat, foundation material, soil
30、, 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 sawing or other satisf
31、actory 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 moisture or solvent and ar
32、e 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 (7777 6 1.8F)1.8Ffor 3 to 5 min then determine the mass by weighing in water. Designate this
33、mass as C. If the temperature of the specimen differsfrom the temperature of the water bath by more than 2C (3.6F),3.6F, the specimen shall be immersed in the water bath for10 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 qu
34、ickly 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 (230230 6 9F).9F. Allow the specimen to cool and weigh
35、in air. Designate this mass as A. Other methodsmay be used to dry the specimen as long as a constant mass is achieved (mass repeats within 0.1 %).NOTE 5Drying the specimen at the required temperature of 110C (230F)230F will change the characteristics and shape of the specimen. Thiswill make the spec
36、imen unsuitable for further testing. Drying the specimen at a reduced temperature such as 52C (125F),125F, in order to keep itintact, 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
37、 is notover-heated 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 c
38、an be determined 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 a
39、t 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 Saturated Surface-Dry Specimen in AirSurface dry the specimen by blotting quickly with a damp cloth toweland then determine the mass by weighing i
40、n air. Designate 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;(B C) = mass of the volume of water for the volume of the specimen at 25C;B = mass of the saturated surface-dry specim
41、en in air, g; andC = mass of the specimen in water, g.A = mass of the dry specimen in air, g lb;(B C) = mass of the volume of water for the volume of the specimen at 25C 77F;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 den
42、sity of the specimen as follows:Density5Bulk sp gr3997.0 or 62.24! (2)where:997.0 = density of water in kg/m3 at 25C (0.9970 g/cm3)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) as follows:D2726/D2726M 133Percent
43、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 fo
44、ot 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 25C,25C 77F,12.1.2 Density of the mixture with four significant figures in kg/m3 or lb/ft3 as: density at 25C,25C 77F,12.1.3 Type of mixture,12.1.4
45、 Size of sample, and12.1.5 Water absorption, %.13. Precision and Bias13.1 Precision:13.1.1 Single Operator PrecisionThe single operator standard deviations (1s limits) for specimens prepared in accordancewith 10.2, for mixtures containing aggregate with absorption of less than 1.5 %, are shown in Ta
46、ble 1. The results of two properlyconducted tests on the same material, by the same operator, using the same equipment, should be considered suspect if they differby more than the d2s single operator limits shown in Table 1.13.1.2 Multilaboratory PrecisionThe multilaboratory standard deviations (1s
47、limits) for specimens prepared in accordancewith 10.2, for mixtures containing aggregate with absorption of less than 1.5 %, are shown in Table 1. The results of two properlyconducted tests on the same material, by different operators, using different equipment, should be considered suspect if they
48、differby more than d2s multilaboratory limits shown in Table 1.13.2 BiasNo information can be presented on the bias of the procedure because no material having an accepted referencevalue is available.14. Keywords14.1 air voids; compaction; density; specific gravity; unit weightSUMMARY OF CHANGESComm
49、ittee D04 has identified the location of selected changes to this standard since the last issue(D2726 10D2726 11) that may impact the use of this standard. (Approved JuneJuly 1, 2010.)2013.)(1) Added oven and temperature measured device. Changed from single to dual units standard.(2) Added new Section 7 on Standardization and new Note 4TABLE 1 Precision EstimatesA1s limit d2s limitSingle Operator Precision:12.5-mm nominal max agg. 0.008 0.02319.0-mm nomin
