1、Designation: D7063/D7063M 11Standard Test Method forEffective Porosity and Effective Air Voids of CompactedBituminous Paving Mixture Samples1This standard is issued under the fixed designation D7063/D7063M; the number immediately following the designation indicates theyear of original adoption or, i
2、n 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.1. Scope1.1 This test method covers the determination of effectiveporosity or effective air vo
3、ids of compacted mixtures by the useof a vacuum sealing method.1.2 This method can be used for compacted field andlaboratory bituminous paving samples, as well as other com-pacted samples with well defined geometrical shapes, such asconcrete cylinders, cored rocks, and metal samples.1.3 The results
4、of this test method can be used to determinethe degree of interconnectivity of air voids within a sample andcan be correlated to permeability of compacted bituminouspaving mixture samples.1.4 A multi-laboratory precision and bias statement for thisstandard has not been developed at this time. Theref
5、ore, thisstandard should not be used for acceptance or rejection of amaterial for purchasing purposes.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalent; therefore, eachsystem shall be use
6、d independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.6 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 s
7、afety and health practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:2D979 Practice for Sampling Bituminous Paving MixturesD4753 Guide for Evaluating, Selecting, and SpecifyingBalances and Standard Masses for Use in Soil, Rock,
8、 andConstruction Materials TestingE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodD5361 Practice for Sampling Compacted Bituminous Mix-tures for Laboratory Testing3. Significance and Use3.1 In this test method a compacted sample is vacuumsealed inside
9、a plastic bag. The density of the sample, SG1, iscalculated using a water displacement method, with the samplesealed. With the sample still in water, the bag is cut open. Sincethe sample is under vacuum and the air voids are evacuated,water will rush in to fill all the water accessible air voids in
10、thecompacted sample. With the saturated weight of sampleknown, an apparent maximum density, SG2, can be calculated.The difference between SG2 and SG1 is the measure of theamount of water that has penetrated the compacted sample.This difference can be used to determine the fraction of totalnumber of
11、voids that are accessible to water, Effective PercentPorosity or Percent Effective Air Voids.3.2 The results obtained from this method can be used todetermine the percentage of total air voids in a compactedsample that can be filled with water through surface orinterconnected paths within the sample
12、. In general, EffectivePercent Porosity should be less than total percent air voids.3.3 This method can be used for 100 mm and 150 mmdiameter cylindrical samples and cubical samples.4. Apparatus4.1 Balance, with ample capacity, and with sufficient sensi-tivity to enable bulk specific gravity of spec
13、imens to becalculated to at least four significant figures, that is to at leastthree decimal places. It shall be equipped with a suitableapparatus3to permit weighing the specimen while it is sus-pended in water. The balance shall conform to Guide D4753 asa class GP2 balance.NOTE 1Since there are no
14、more significant figures in the quotient1This 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 edition approved on June 1, 2011. Published July
15、 2011. Originallypublished in 2005. Last approved in 2005 as D706305DOI: 10.1520/D7063_D7063M-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Docum
16、ent Summary page onthe ASTM website.3The sole source of supply of the apparatus and the method known to thecommittee at this time is InstroTek, Inc., Raleigh, NC. If you are aware of alternativesuppliers, please provide this information to ASTM Headquarters. Your commentswill receive careful conside
17、ration at a meeting of the responsible technicalcommittee,1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.(bulk specific gravity) than appear in either the dividend (the mass of thespecimen in air) or in the divisor (the volume of th
18、e specimen, obtainedfrom the difference in mass of the specimen in air and in water), thismeans that the balance must have a sensitivity capable of providing bothmass and volume values to at least four figures. For example, a sensitivityof 0.1 g 0.00022 lb would provide four significant figures for
19、thedetermination of a mass in the range from 130.0 to 999.9 g 0.29 to 2.20lb when the specific gravity is 2.300.4.2 Water Bath, with minimum dimensions (Length 3Width 3 Depth) of 610 3 460 3 460 mm 24 3 18 3 18 in.or a large cylindrical container with a minimum diameter of460 mm and depth of 460 mm
20、18 3 18 in., for completelysubmerging the specimen in water while suspended, equippedwith an overflow outlet for maintaining a constant water leveland temperature controls to maintain the water temperature at25 6 1 C 77 6 2 F.NOTE 2It is preferable to keep the water temperature constant byusing a te
21、mperature controlled heater. Also, to reduce the chance for thebag to touch the sides of the water tank, it is preferable to elevate the watertank to a level at which the sample can be placed on the weighingmechanism while the operator is standing up (waist height), and theplacement of the sample an
22、d the bag in the water tank can easily beinspected.4.3 Cushioned holder, for water displacement of the sample,having no sharp edges.NOTE 3To avoid accidental puncture of the plastic bags in the waterbath, plastic coated cushioned holders have been found to work well forthis test method.4.4 Vacuum Ch
23、amber, with a pump capable of evacuating asealed and enclosed chamber to a pressure of 6 mm Hg 6Torr, when at sea level. The chamber shall be large enough totest samples 150 mm 6 in. wide by 350 mm 14 in. long by150 mm 6 in. thick. The device shall automatically seal theplastic bag and exhaust air b
24、ack into the chamber in acontrolled manner to ensure proper conformance of the plasticto the specimen. The air exhaust and vacuum operation timeshall be set at the factory so that the chamber is brought toatmospheric pressure in 80 to 125 seconds, after the comple-tion of the vacuum operation . The
25、vacuum system shall beprovided with a latch to control the chamber door opening.4.5 A Vacuum Measurement Gage, independent of thevacuum sealing device that could be placed directly inside thechamber to verify vacuum performance and the chamber doorsealing condition of the unit. The gage shall be cap
26、able ofreading down to 3 mm Hg 3 Torr and readable to 1 mm Hg1 Torr.4.6 Plastic Bags, used with the vacuum device shall be oneof the two following sizes. The smaller bags shall have aminimum opening of 235 mm 9.25 in. and maximum openingof 260 mm 10.25 in. and the larger bags shall have aminimum ope
27、ning of 375 mm 14.75 in. and a maximumopening of 394 mm 15.5 in. The bags shall be of plasticmaterial that will not adhere to asphalt film, is punctureresistant, is capable of withstanding sample temperatures of upto 70C 158, is impermeable and contains no air channelsfor evacuation of air from the
28、bag. The bags shall have aminimum thickness of 0.127 mm 0.005 in. and maximumthickness of 0.178 mm 0.007 in. The apparent specificgravity for the bags shall be provided by the manufacturer foreach bag shipment. The apparent specific gravities provided foreach size bag shall account for the different
29、 sample weights andbag weight used during testing.4.7 Specimen Sliding Plate, used within the chamber forreduction of friction on the plastic bags.4.8 Bag Cutting Knife, or scissors.4.9 Thermometer, readable to 1 C 2 F.5. Verification5.1 System Verification:5.1.1 The vacuum settings of the device sh
30、all be verifiedonce every three months, after major repairs, and after eachshipment or relocation.5.1.2 Place the gage inside the chamber and record thesetting. The gage shall indicate a pressure of 6 mm Hg 6TORR or less. The unit should not be used if the gage readingis above 6 mm Hg 6 TORR.5.1.3 V
31、acuum gage used for verification shall be verified foraccuracy once every three years.NOTE 4On line vacuum gages, while capable of indicating vacuumperformance of the pump, are not suitable for use in enclosed vacuumchambers and can not accurately measure vacuum levels.6. Sampling6.1 Test specimens
32、shall be molded from laboratory pre-pared samples or taken from the pavement in the field. Obtainfield samples in accordance with Practice D979 and D5361.7. Test Specimen7.1 It is recommended, (1) that the diameter of cylindricallymolded or cored specimens, or the length of the sides of sawedspecime
33、ns be at least equal to four times the maximum size ofthe aggregate; and (2) that the thickness of specimens be atleast one and one half times the maximum size of theaggregate. Pavement specimens are to be taken by such meansas coring, sawing of blocks, and so forth.7.2 Take care to avoid distortion
34、, bending, or cracking ofspecimens during and after removal from pavement or mold.Store specimens in a safe, cool place.7.3 Specimens shall be free of foreign materials, such assealcoat, tack coat, foundation material, soil, paper, or foil.When any of these materials are visually evident, they shall
35、 beremoved. Sealcoat or tackcoat, or both, may be removed bysawing the bottom or the top faces, or both, of the sample.7.4 If desired, separate specimens from other pavementlayers by sawing or other suitable means.7.5 Use a brush or a soft sanding block to break sharp edgesaround the top and bottom
36、corners of the sample.8. Procedure8.1 Set the vacuum chamber to operate at a pressure of 6mm Hg 6 Torr for a minimum of 5 minutes8.2 Mass of Unsealed Specimen:8.2.1 Laboratory Prepared SpecimensDetermine themass of the specimen after it has cooled to room temperature.Designate this mass as A.8.2.2 C
37、ores and Specimens Containing MoistureDry thespecimen to constant mass. Designate this mass as A. ConstantD7063/D7063M 112mass is defined as less than 0.05 % change in mass betweenconsecutive drying intervals.NOTE 5For accurate porosity determination, specimen should not bedried in the oven at tempe
38、ratures above 30 C 85F. Oven drying willdamage sample integrity. Vacuum drying method for drying specimens isideal for this test method.8.3 Mass of Sealed Specimen:8.3.1 Select an appropriate size bag. For all 100 mm 4 in.diameter samples and samples with 150 mm 6 in. diameterand less than 50 mm 2 i
39、n. thickness, use the bag with smalleropening size as specified in 4.6. For 150 mm 6 in. sampleswith greater than 50 mm 2 in. thickness, use the largeropening size bags as specified in 4.6. For samples that weighmore than 5500 g 12.13 lb, use manufacturers recommen-dation for appropriate bag size an
40、d configuration.NOTE 6Protect the bag during storage. Rough handling, storing inproximity to sharp objects such as tools, aggregate, or inside drawers willdamage the plastic bag. Refer to manufacturers recommendation forhandling and safe storage.8.3.2 Inspect the bag for holes or irregularities, rec
41、ord themass of the bag and place the bag inside the vacuum chamberon top of the specimen sliding plate.8.3.3 Gently open the bag and place the specimen in theplastic bag on top of the specimen sliding plate, being carefulto handle the bag in such a manner that would prevent apuncture. Avoid dropping
42、 or impacting the bag, and followmanufacturers recommendations for handling the specimensand the bags.8.3.4 Allow the vacuum chamber to remove the air from thechamber and the plastic bag. The vacuum chamber shallautomatically seal the bag after the vacuum operations hasbeen completed.8.3.5 Exhaust a
43、ir into the chamber until the chamber dooropens indicating atmospheric pressure within the chamber. Thechamber door latch can be used to avoid automatic opening ofthe door after completion of the test.8.3.6 Remove the sealed sample from the vacuum chamber.Handle the sealed sample with extreme care t
44、o preventpuncturing the bag. Gently pull on the bag and if the bag easilyseparates from the sample, the bag may be punctured; repeatthe sealing process with a new bag.8.3.7 Determine the mass of the sealed specimen in air bysumming mass A and the mass of the bag obtained in step8.3.2. Designate this
45、 mass as B.8.3.8 Place the sealed sample in the water bath equippedwith a scale. Determine the mass of the sealed specimen in thewater bath at 25 61C 77 62F. Designate this mass as E.Make certain the sample is completely suspended in the wateron top of the cushioned holder that is attached to scales
46、. Thebag shall not be floating out of the water and it shall not betouching the sides or the bottom of the water tank. Ensure thatthe temperature of water is set at 25 6 1C 77 6 2F8.3.9 With the sample and the bag completely submerged inwater, use scissors to cut the bag open. This allows the watert
47、o rush into all water accessible voids in the sample.8.3.10 Allow the sample to remain under water for at least4 minutes. Record and designate this mass as C. The bag shallnot be floating out of the water and it shall not be touching thesides or the bottom of the water tank.9. Calculation9.1 Calcula
48、te the bulk specific gravity of the sealed speci-men as follows:Bulk Specific Gravity 5 SG1 5AB 2 E 2B 2 AFT(1)where:A = mass of dry specimen in air, g,B = mass of dry, sealed specimen, g,E = mass of sealed specimen underwater, g, andFT= apparent specific gravity of plastic sealing material at25 6 1
49、C 77 6 2F, when sealed, provided by themanufacturer.9.2 Calculate the apparent specific gravity (gravity with thebag open) of the sample as follows:Apparent Specific Gravity 5 SG2 5AB 2 C 2B 2 AFT1(2)C = mass of unsealed specimen underwater, g, andFT1= apparent specific gravity of plastic sealing materialat 25 6 1C 77 6 2F when opened under water ,provided by the manufacturer.% Porosity 5 % Effective Air Voids 5SG2 2 SG1SG23 100 (3)10. Report10.1 Report the following information:10.1.1 Appa
