ASTM D7063-2005 Standard Test Method for Effective Porosity and Effective Air Voids of Compacted Bituminous Paving Mixture Samples《压实沥青铺路混合料样品的有效孔隙率和有效气隙的标准试验方法》.pdf

1、Designation: D 7063 05Standard Test Method forEffective Porosity and Effective Air Voids of CompactedBituminous Paving Mixture Samples1This standard is issued under the fixed designation D 7063; the number immediately following the designation indicates the year oforiginal adoption or, in the case o

2、f revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of effectiveporosity or effective air voids of comp

3、acted 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 of this tes

4、t 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. Therefore, thisst

5、andard should not be used for acceptance or rejection of amaterial for purchasing purposes.1.5 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 practi

6、ces and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:2D 979 Practice for Sampling Bituminous Paving MixturesD 4753 Guide for Evaluating, Selecting, and SpecifyingBalances and Standard Masses for Use in Soil, Rock, andConstruction Mate

7、rials TestingE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodD 5361 Standard Practice for Sampling Compacted Bitumi-nous Mixtures for Laboratory Testing3. Significance and Use3.1 In this test method a compacted sample is vacuumsealed inside a plastic

8、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 thecompact

9、ed 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 voids that

10、 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. In gener

11、al, 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. Definitions4.1 Porosity and Effective Air VoidsTotal amount of airvoids within a compacted sample that can be saturated by wa

12、terthrough paths starting from the surface of the sample (surfaceconnected or interconnected voids).5. Apparatus5.1 Balance, with ample capacity, and with sufficient sensi-tivity to enable bulk specific gravity of specimens to becalculated to at least four significant figures, that is to at leastthr

13、ee decimal places. It shall be equipped with a suitable1This 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 Sept. 15, 200

14、5. Published September 2005.2For 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 Document Summary page onthe ASTM website.1Copyright ASTM International, 10

15、0 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.apparatus3to permit weighing the specimen while it is sus-pended in water. The balance shall conform to Guide D 4753 asa class GP2 balance.NOTE 1Since there are no more significant figures in the quotient(bulk specific

16、 gravity) than appear in either the dividend (the mass of thespecimen in air) or in the divisor (the volume of the 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

17、 at least four figures. For example, a sensitivityof 0.1 g would provide four significant figures for the determination of amass in the range from 130.0 to 999.9 g when the specific gravity is 2.300.5.2 Water Bath, with minimum dimensions (Length 3Width 3 Depth) of 610 3 460 3 460 mm (24 3 18 3 18 i

18、n.)or a large cylindrical container with a minimum diameter of460 mm and depth of 460 mm (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

19、 6 1 C (77 6 2 F).NOTE 2It is preferable to keep the water temperature constant byusing a temperature 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 weighingm

20、echanism while the operator is standing up (waist height), and theplacement of the sample and the bag in the water tank can easily beinspected.5.3 Cushioned holder, for water displacement of the sample,having no sharp edges.NOTE 3To avoid accidental puncture of the plastic bags in the waterbath, pla

21、stic coated cushioned holders have been found to work well forthis test method.5.4 Vacuum Chamber, with a pump capable of evacuating asealed and enclosed chamber to a pressure of 6 mm Hg, whenat sea level. The chamber shall be large enough to test samples150 mm wide by 350 mm long by 150 mm thick. T

22、he deviceshall automatically seal the plastic bag and exhaust air backinto the chamber in a controlled manner to ensure properconformance of the plastic to the specimen. The air exhaust andvacuum operation time shall be set at the factory so that thechamber is brought to atmospheric pressure in 80 t

23、o 125seconds, after the completion of the vacuum operation . Thevacuum system shall be provided with a latch to control thechamber door opening.5.5 A Vacuum Measurement Gage, independent of thevacuum sealing device that could be placed directly inside thechamber to verify vacuum performance and the

24、chamber doorsealing condition of the unit. The gage shall be capable ofreading down to 3 mm Hg and readable to 1 mm Hg.5.6 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

25、(10.25 in.) and the larger bags shall have aminimum opening 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, is impermeable and

26、 contains no air channels forevacuation of air from the bag. The bags shall have a minimumthickness of 0.127 mm (0.005 in.) and maximum thickness of0.178 mm (0.007 in.). The apparent specific gravity for thebags shall be provided by the manufacturer for each bagshipment. The apparent specific gravit

27、ies provided for eachsize bag shall account for the different sample weights and bagweight used during testing.5.7 Specimen Sliding Plate, used within the chamber forreduction of friction on the plastic bags.5.8 Bag Cutting Knife, or scissors.5.9 Thermometer, readable to 1 C (2 F).6. Verification6.1

28、 System Verification:6.1.1 The vacuum settings of the device shall be verifiedonce every three months, after major repairs, and after eachshipment or relocation.6.1.2 Place the gage inside the chamber and record thesetting. The gage shall indicate a pressure of 6 mm Hg (6TORR) or less. The unit shou

29、ld not be used if the gage readingis above 6 mm Hg (6 TORR).6.1.3 Vacuum 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

30、not accurately measure vacuum levels.7. Sampling7.1 Test specimens shall be molded from laboratory pre-pared samples or taken from the pavement in the field. Obtainfield samples in accordance with Practice D 979 and D 5361.8. Test Specimen8.1 It is recommended, (1) that the diameter of cylindrically

31、molded or cored specimens, or the length of the sides of sawedspecimens 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 cor

32、ing, sawing of blocks, and so forth.8.2 Take care to avoid distortion, bending, or cracking ofspecimens during and after removal from pavement or mold.Store specimens in a safe, cool place.8.3 Specimens shall be free of foreign materials, such assealcoat, tack coat, foundation material, soil, paper,

33、 or foil.When any of these materials are visually evident, they shall beremoved. Sealcoat or tackcoat, or both, may be removed bysawing the bottom or the top faces, or both, of the sample.8.4 If desired, separate specimens from other pavementlayers by sawing or other suitable means.8.5 Use a brush o

34、r a soft sanding block to break sharp edgesaround the top and bottom corners of the sample.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

35、Headquarters. Your commentswill receive careful consideration at a meeting of the responsible technicalcommittee,D70630529. Procedure9.1 Set the vacuum chamber to operate at a pressure of 6mm Hg for a minimum of 5 minutes9.2 Mass of Unsealed Specimen:9.2.1 Laboratory Prepared SpecimensDetermine them

36、ass of the specimen after it has cooled to room temperature.Designate this mass as A.9.2.2 Cores and Specimens Containing MoistureDry thespecimen to constant mass. Designate this mass as A. Constantmass is defined as less than 0.05 % change in mass betweenconsecutive drying intervals.NOTE 5For accur

37、ate porosity determination, specimen should not bedried in the oven at temperatures above 30 C. Oven drying will damagesample integrity. Vacuum drying method for drying specimens is ideal forthis test method.9.3 Mass of Sealed Specimen:9.3.1 Select an appropriate size bag. For all 100 mm (4 in.)diam

38、eter samples and samples with 150 mm (6 in.) diameterand less than 50 mm (2 in.) thickness, use the bag with smalleropening size as specified in 5.6. For 150 mm (6 in.) sampleswith greater than 50 mm (2 in.) thickness, use the largeropening size bags as specified in 5.6. For samples that weighmore t

39、han 5500 g, use manufacturers recommendation forappropriate bag size and 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

40、and safe storage.9.3.2 Inspect the bag for holes or irregularities, record themass of the bag and place the bag inside the vacuum chamberon top of the specimen sliding plate.9.3.3 Gently open the bag and place the specimen in theplastic bag on top of the specimen sliding plate, being carefulto handl

41、e the bag in such a manner that would prevent apuncture. Avoid dropping or impacting the bag, and followmanufacturers recommendations for handling the specimensand the bags.9.3.4 Allow the vacuum chamber to remove the air from thechamber and the plastic bag. The vacuum chamber shallautomatically sea

42、l the bag after the vacuum operations hasbeen completed.9.3.5 Exhaust air 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.9.3.6 Remove the sealed samp

43、le from the vacuum chamber.Handle the sealed sample with extreme care to 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.9.3.7 Determine the mass of the sealed specimen in air bysummi

44、ng mass A and the mass of the bag obtained in step9.3.2. Designate this mass as B.9.3.8 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 suspen

45、ded in the wateron top of the cushioned holder that is attached to scales. 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 2F)9.3.9 With the sample and the bag completely

46、submerged inwater, use scissors to cut the bag open. This allows the waterto rush into all water accessible voids in the sample.9.3.10 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

47、touching thesides or the bottom of the water tank.10. Calculation10.1 Calculate 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 underwa

48、ter, g, andFT= apparent specific gravity of plastic sealing material at25 6 1C (77 6 2F), when sealed, provided by themanufacturer.10.2 Calculate the apparent specific gravity (gravity withthe bag open) of the sample as follows:Apparent Specific Gravity 5 SG2 5AB 2 C 2B 2 AFT1(2)C = mass of unsealed

49、 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)11. Report11.1 Report the following information:11.1.1 Apparent specific gravities of plastic bags to foursignificant figures.11.1.2 Bulk specific gravity of compacted sample at 25 61C (77 6 2F) to four significant figures.11.1.3 Apparent specific gravity of compacted sample at 256 1C (77 6 2F) to four significant figures.11.1.4 Effective