1、Designation: D6539 00 (Reapproved 2006)2D6539 13Standard Test Method forMeasurement of Pneumaticthe Permeability of PartiallySaturated Unsaturated Porous Materials by Flowing Air 1This standard is issued under the fixed designation D6539; the number immediately following the designation indicates th
2、e year oforiginal adoption or, in the case of revision, 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.1 NOTEMercury warning editorially added in March 2008.2 NOTE E
3、ditorially moved mercury warning to follow Section 5.3.1 in May 2008.1. Scope1.1 This test method covers laboratory determination of the coefficient of permeability for the flow of air (pneumaticpermeability) through partially saturated through unsaturated porous materials.1.2 This test method may b
4、e used with undisturbedintact or compacted coarse grained soils, silts, or lean cohesive soils that havea low degree of saturation and that have pneumatic permeability between 0.001 square micrometre1.0 10-15 m2 (1.01 millidarcy)and 100 square micrometre1.0 10-10 m2 (101 darcy).1.3 The values stated
5、 in SI units are to be regarded as the standard, unless other units are specifically given. By tradition in U.S.practice, the pneumatic permeability of porous media is reported in units of darcy, although the SI unit for pneumatic permeabilityis square metre. standard.1.3.1 By tradition in U.S. prac
6、tice, the permeability of porous media is reported in units of darcy, although the SI unit forpermeability is m2.1.4 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in PracticeD6026.1.4.1 For the purpose of comparing a measured or ca
7、lculated value with specified limits, the measured or calculated value shallbe rounded to the same precision as the specified limits.1.4.2 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industrystandard. In addition, they are repres
8、entative of the significant digits that generally should be retained. The procedures used do notconsider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the users objectives;and it is common practice to increase or reduce significant digits of r
9、eported data to be commensurate with these considerations.It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the respon
10、sibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and Contained FluidsD698 Test Methods for Laboratory Com
11、paction Characteristics of Soil Using Standard Effort (12 400 ft-lbf/ft3 (600 kN-m/m3)D854 Test Methods for Specific Gravity of Soil Solids by Water PycnometerD1557 Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3 (2,700kN-m/m3)D1557 Test Method
12、s for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3 (2,700kN-m/m3)1 This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.04 on Hydrologic Propertiesand Hydraulic Barriers.Curren
13、t edition approved Feb. 1, 2006May 1, 2013. Published March 2006July 2013. Originally approved in 2000. Last previous edition approved in 2000 as D653900. 00 (2006)2. DOI: 10.1520/D6539-00R06E02.10.1520/D6539-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Cust
14、omer 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 indication of what changes have been made to th
15、e 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 considered the official document.Copyright A
16、STM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by MassD3550 Practice for Thick Wall, Ring-Lined, Split Barrel, Drive Sampling of SoilsD3740 Practice fo
17、r Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used inEngineering Design and ConstructionD4220 Practices for Preserving and Transporting Soil SamplesD4525 Test Method for Permeability of Rocks by Flowing AirD4564 Test Method for Density and Unit Weight o
18、f Soil in Place by the Sleeve Method (Withdrawn 2013)3D4753 Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and ConstructionMaterials TestingD4767 Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive SoilsD5084 Test Methods
19、 for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible WallPermeameterD5856 Test Method for Measurement of Hydraulic Conductivity of Porous Material Using a Rigid-Wall, Compaction-MoldPermeameterD6026 Practice for Using Significant Digits in Geotechnical DataE1 Spe
20、cification for ASTM Liquid-in-Glass ThermometersE145 Specification for Gravity-Convection and Forced-Ventilation OvensE2251 Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids3. Terminology3.1 DefinitionsFor definitions of technical terms in this standard, refer to
21、Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 darcya porous medium has a permeability of one darcy when a single-phase fluid of 1-MPashaving a viscosity of 10-3Pas (1-cP) viscosity that completely fills the voids of the medium will flow through it under conditions of lami
22、nar (viscous) flowconditions at a rate of 1 cmm3/s/cm per 1 m2 of cross-sectional area under a pressure gradient of 1.013 105 PaPa/m (1atm)/cm.atm/m). (One darcy = 0.9869 square micro9.869 10-13 metre.)m2.)3.2.2 effective confining stress, (Flexible Wall Method only)the difference between the permea
23、meter cell confining pressureand the mean specimen pore-air-water pressures.3.2.2.1 The effective confining stress is assumed to be distributed as a radial vector exhibiting a linear gradient along the lengthof the specimen with a minimum at the inlet and a maximum at the outlet.3.2.2.2 For the purp
24、oses of this test method, the effective confining stress is stated as a scalar value and calculated as theconfining gage pressure minus the average of the specimen inlet and outlet gage pressures.3.2.3 gage pressurepressure measured relative to ambient atmospheric pressure.3.2.4 pneumatic permeabili
25、tythe capacity of a porous medium to conduct gas in the presence of a gas (air) pressure gradientmeasured as the ratio of volumetric flow rate of air through a specimen to the resultant pressure drop across it. Also the specimen.(Also commonly known as pneumaticconductivity or permeability to air.)3
26、.2 For definitions of other terms used in this test method, see Terminology D653.4. Significance and Use4.1 This test method applies to the one-dimensional laminar (viscous) flow of air in porous materials such as soil.NOTE 1This test method deals with porous materials with both gaseous (air) and li
27、quid (pore water) mobile fluids: The liquid phase is much lesscompressible, has a higher viscosity, and is much more tightly bound to the solid phase by chemical forces. The assumption of single-phase flow maystill be presumed to be valid since the test gradient ensuring the conditions of laminar fl
28、ow may be low enough that flow of the liquid phase is negligible.3 The last approved version of this historical standard is referenced on www.astm.org.TABLE 1 Viscosity of Air, , as a Function of TemperatureTemperature, C Viscosity, Pas12 1.778 10514 1.788 10516 1.798 10518 1.808 10520 1.818 10522 1
29、.828 10524 1.837 10526 1.847 10528 1.857 105D6539 1324.2 The degree of saturation of the specimen shall be less than that which would produce significant internal transport of porewater or alter the continuity of air voids under the applied pneumatic gradients. The maximum permissible degree of satu
30、rationmust be evaluated by an experienced analyst. In no instance shall the specimen be so saturated that pore water appears at the exitof the permeameter cell during the test.4.3 This test method is based on the assumption that the rate of mass flow through the specimen is constant with time.NOTE 2
31、When a specimen contains volatile materials this assumption is violated. The mass of gas flowing out will be greater than that flowing in,the pneumatic gradient is indeterminate gradient cannot be determined and the test may become meaningless. Such specimens pose special problems andmust be deconta
32、minated before analysis in order to minimize health and safety concerns and to prevent contamination of the test apparatus.4.4 The pneumatic permeability of porous materials may be strongly dependent on a variety of physical properties includingthe void ratio, the degree of saturation, and percent a
33、nd direction of compaction, and so forth. compaction. It is beyond the scopeof this test method to elaborate upon these dependencies. Rather, this test method is intended to be a measurement technique fordetermining the pneumatic permeability under a certain set of laboratory conditions. It is the r
34、esponsibility of the test requestorto specify which soil parameters must be controlled to ensure a valid extension of the test results to field conditions.4.5 It is assumed that Darcys Law is valid. The validity of Darcys law mayCalculation of the permeability using Darcys lawrequires laminar flow c
35、onditions through the soil specimen. The conditions for laminar flow shall be evaluated by plotting thevolumetric flow rate of air through the specimen against the differential pressure drop across the specimen. If the individual testpoints lie within 25 % 25 % of a straight line passing through the
36、 origin, then laminar flow conditions are present and Darcys lawmay be taken as valid.used to calculate the permeability.NOTE 3Darcys law The permeability calculated using this standard is valid only when the degree of saturation does not change over time. Longmeasurement times associated with the u
37、se of bubble meters and manometers may indirectly be an uncontrolled source of lead to variability whenplottingmeasuring flow versus pressure drop (see 8.2). ) due to evaporation. The recommended use of digital electronic flow and pressure sensors leadsto considerably reduced measurement times becau
38、se the user can quickly determine by inspection when a steady state condition has been reached.At thatpoint only a single reading needs to be taken for a reliable measurement. A rapid course of measurement will minimize dehydration of partially saturatedunsaturated specimens.NOTE 4Humidifying the te
39、st gas to minimize specimen dehydration is not recommended because: (1) there is no practical way to either measure orcontrol the relative humidity of the test gas, either at the inlet or outlet of the specimen; (2) the calibration of the electronic flowmeter is typical digitalflowmeters are general
40、ly for dry air only and would become unreliable in the presence of water vapor, especially in view of the potential for irreversibleadsorption of moisture on the sensor elements; (3) there is a danger of permanent water condensation in the static transfer lines and other apparatus deadvolumes; and (
41、4) the test apparatus would become more complex and difficult to use.4.6 This test method covers the use of two different types of permeameter cells, flexible wall cells (flexible and rigid wall, wallpermeameters) and two types of air flow regulation, massregulation (mass flow control and pressure c
42、ontrol.control).4.7 Aflexible wall permeameter is the preferred means for confining the test specimen in accordance with Test Methods D5084,D4525, and D4767. This test method may still be performed using a rigid wall permeameter andpermeameter, but all reference toeffective confining stress and the
43、permeameter cell pressure system shall then be disregarded.4.8 For some specimens, the pneumatic permeability will be strongly dependent on the effective confining stress due to porosityreduction. Whenever possible, the requestor shouldshall specify the field overburden conditions at which this test
44、 method is to beperformed. In some specimens, this stress will vary significantly with flow in an indeterminate way. All specimens shouldshall beevaluated for this effect by performing this test method at two or more different confining stress values when a flexible wallpermeameter is used.4.9 This
45、test method is intended to support soil remediation operations such as: soil vapor extraction, air sparging, backfillingof soils in utility trenches, and similar engineering activities.4.10 The correlation between results obtained with this test method and in situ field measurements has only been pa
46、rtiallyestablished. The small laboratory specimen used in this method may not be representative of the distributed condition on-site dueto vadose zone fluctuations, changes in soil stratigraphy, and so forth. For this reason, laboratory test results should be applied tofield situations with caution
47、by qualified personnel. caution should be used by qualified personnel when applying laboratory testresults to field situations.NOTE 5This test method is dependent on the competence of the personnel performing it and the suitability of the equipment and facilities used.Agencies which meet the criteri
48、on of Practice D3740 are generally considered capable of competent and objective testing.5. Apparatus5.1 Pneumatic PermeameterThe pneumatic permeameter shall be capable of rapidly establishing a constant flow of airthrough the test specimen and measuring the consequent pressure drop across it. A sch
49、ematic diagram is shown in Fig. 1.5.1.1 Air SupplyThe compressed air supplied to the pneumatic system shall:5.1.1.1 Be pulsation-free, have sufficient volumetric capacity at all anticipated flow rates, be free of water vapor to a dew pointof 70C (94F) or less, and be free of oil,5.1.1.2 Be free of particulate matter greater than 5 m in diameter, and5.1.1.3 Be provided with a monitoring gage and regulator to deliver a pressure of at least 350 6 5 kPa (50 6 1 psi). kPa.D6539 133NOTE 6Other gases than air may
