ASTM D6035-2008 780 Standard Test Method for Determining the Effect of Freeze-Thaw on Hydraulic Conductivity of Compacted or Intact Soil Specimens Using a Flexible Wall Permeameter.pdf

1、Designation: D 6035 08Standard Test Method forDetermining the Effect of Freeze-Thaw on HydraulicConductivity of Compacted or Intact Soil Specimens Usinga Flexible Wall Permeameter1This standard is issued under the fixed designation D 6035; the number immediately following the designation indicates t

2、he 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers laboratory measurement

3、of theeffect of freeze-thaw on the hydraulic conductivity of com-pacted or intact soil specimens using Test Method D 5084 anda flexible wall permeameter to determine hydraulic conductiv-ity. This test method does not provide steps to performsampling of, or testing on, in situ soils that have already

4、 beensubjected to freeze-thaw conditions.1.2 This test method may be used with intact specimens(block or thin-walled) or laboratory compacted specimens andshall be used for soils that have an initial hydraulic conduc-tivity less than or equal to 1E-5 m/s (1E-3 cm/s) (Note 1).NOTE 1The maximum initia

5、l hydraulic conductivity is given as 1 E-3cm/s. This should also apply to the final hydraulic conductivity. It isexpected that if the initial hydraulic conductivity is 1 E-3 cm/s, then thefinal hydraulic conductivity will not change (increase) significantly (thatis, greater than 1 E-3 cm/s).1.3 Soil

6、 specimens tested using this test method can besubjected to three-dimensional freeze-thaw (herein referred toas 3-d) or one-dimensional freeze-thaw (herein referred to as1-d). (For a discussion of one-dimensional freezing versusthree-dimensional freezing, refer to Zimmie2or Othman.3)1.4 Soil specime

7、ns tested using this test method can betested in a closed system (that is, no access to an externalsupply of water during freezing) or an open system.1.5 The values stated in SI units are to be regarded as thestandard, unless other units are specifically given. By tradition,it is U.S. practice to re

8、port hydraulic conductivity in centime-tres per second, although the common SI units for hydraulicconductivity are metres per second. The values are to becalculated and reported in accordance with Practice D 6026.1.6 This standard does not purport to address all of thesafety concerns, if any, associ

9、ated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:4D 653 Terminology Relating to Soil, Rock, and ContainedFlui

10、dsD 1587 Practice for Thin-Walled Tube Sampling of Soilsfor Geotechnical PurposesD2113 Practice for Rock Core Drilling and Sampling ofRock for Site InvestigationD 2216 Test Methods for Laboratory Determination of Wa-ter (Moisture) Content of Soil and Rock by MassD 3740 Practice for Minimum Requireme

11、nts for AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionD 4220 Practices for Preserving and Transporting SoilSamplesD 4753 Guide for Evaluating, Selecting, and SpecifyingBalances and Standard Masses for Use in Soil, Rock, andConstruction

12、 Materials TestingD 5084 Test Methods for Measurement of Hydraulic Con-ductivity of Saturated Porous Materials Using a FlexibleWall PermeameterD 6026 Practice for Using Significant Digits in Geotechni-cal Data1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the

13、 direct responsibility of Subcommittee D18.19 on Frozen Soils andRock.Current edition approved Jan. 1, 2008. Published February 2008. Originallyapproved in 1996. Last previous edition approved in 2002 as D 6035 02.2Zimmie, T. F., and La Plante, C., “The Effect of Freeze/Thaw Cycles on thePermeabilit

14、y of a Fine-Grained Soil,” Hazardous and Industrial Wastes, Proceed-ings of the Twenty-Second Mid-Atlantic Industrial Waste Conference, Joseph P.Martin, Shi-Chieh Cheng, and Mary Ann Susavidge, eds., Drexel University, 1990,pp. 580593.3Othman, M. A., Benson, C. H., Chamberlain, E. J., and Zimmie, T.

15、 F.,“Laboratory Testing to Evaluate Changes in Hydraulic Conductivity of CompactedClays Caused by Freeze-Thaw: State-of-the-Art,” Hydraulic Conductivity andWaste Contaminant Transport in Soils, ASTM STP 1142, David E. Daniel, andStephen J. Trautwein, eds., American Society for Testing and Materials,

16、 Consho-hocken, PA, pp. 227254.4For 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.1*A Summary of Changes section

17、 appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.E 145 Specification for Gravity-Convection and Forced-Ventilation Ovens3. Terminology3.1 Definitions: For common definitions of other terms inthis st

18、andard, see Terminology D 653.3.1.1 Hydraulic conductivityRefer to Terminology D 653for standard definition of this term.3.2 Definitions of Terms Specific to This Standard:3.2.1 freeze-thaw cycle, na loop from room temperatureto the ambient temperature of the freezing cabinet, and back toroom temper

19、ature.3.2.2 freezing, closed system, nfreezing that occurs underconditions that preclude the gain or loss of any water in thesystem.3.2.3 freezing, open system, nfreezing that occurs underconditions that allow the gain or loss of water in the system bymovement of pore water from or to an external so

20、urce togrowing ice lenses.4. Significance and Use4.1 This test method identifies the changes in hydraulicconductivity as a result of freeze-thaw on natural soils only.4.2 It is the users responsibility when using this test methodto determine the appropriate moisture content of thelaboratory-compacte

21、d specimens (that is, dry, wet, or at opti-mum moisture content) (Note 2).NOTE 2It is common practice to construct clay liners and covers atoptimum or greater than optimum moisture content. Specimens com-pacted dry of optimum moisture content typically do not contain largerpore sizes as a result of

22、freeze-thaw because the effects of freeze-thaw areminimized by the lack of water in the sample. Therefore, the effect offreeze-thaw on the hydraulic conductivity is minimal, or the hydraulicconductivity may increase slightly.3,54.3 The requestor must provide information regarding theeffective stress

23、es to be applied during testing, especially fordetermining the final hydraulic conductivity. Using high effec-tive stresses (that is, 35 kPa (5 psi) as allowed by Test MethodD 5084) can decrease an already increased hydraulic conduc-tivity resulting in lower final hydraulic conductivity values.The l

24、ong-term effect of freeze-thaw on the hydraulic conduc-tivity of compacted soils is unknown. The increased hydraulicconductivity caused by freeze-thaw may be temporary. Forexample, the overburden pressure imparted by the waste placedon a soil liner in a landfill after being subjected to freeze-thawm

25、ay reduce the size of the cracks and pores that cause theincrease in hydraulic conductivity. It is not known if thepressure would overcome the macroscopically increased hy-draulic conductivity sufficiently to return the soil to its originalhydraulic conductivity (prior to freeze-thaw). For cases suc

26、h aslandfill covers, where the overburden pressure is low, theincrease in hydraulic conductivity due to freeze-thaw willlikely be permanent. Thus, the requestor must take the appli-cation of the test method into account when establishing theeffective stress.4.4 The specimen shall be frozen to 15C un

27、less therequestor specifically dictates otherwise. It has been docu-mented in the literature that the initial (that is, 0 to 15C)freezing condition causes the most significant effects3inhydraulic conductivity. Freezing rate and ultimate temperatureshould mimic the field conditions. It has been shown

28、 thatsuperfreezing (that is, freezing the specimen at very coldtemperatures and very short time periods) produces erroneousresults.4.5 The thawed specimen temperature and thaw rate shallmimic field conditions. Thawing specimens in an oven (that is,overheating) will produce erroneous results.4.6 Lite

29、rature relating to this subject indicates that theeffects of freeze-thaw usually occur by Cycle 10, thus it isrecommended that at least 10 freeze-thaw cycles shall beperformed to ensure that the full effects of freeze-thaw aremeasured. If the hydraulic conductivity values are still increas-ing after

30、 10 freeze-thaw cycles, the test method shall becontinued (that is, more freeze-thaw cycles shall be per-formed).NOTE 3The quality of the result produced by this standard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies t

31、hat meet thecriteria of Practice D 3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D 3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D

32、3740provides a means of evaluating some of those factors.5. Apparatus5.1 Freezing Cabinet, capable of maintaining at least 1561C.5.2 The apparatus listed in Test Method D 5084 (see 5.1through section 5.18).6. Reagents6.1 Deaired WaterTo aid in removing as much air fromthe specimen as possible during

33、 the hydraulic conductivityportion of the test, deaired water shall be used.6.2 OptionalIf the specimen is frozen/thawed in theflexiwall permeameter, a mixture of propylene glycol and tapwater can be placed in the flexi-wall permeameter cell. Thecompatibility of the mixture and membrane used shall b

34、edetermined. Membranes may degrade and cause cell leakage.This mixture should have a freezing point lower than theambient temperature of the freezing cabinet. The specimen willfreeze, but the cell fluid will not. This allows the total stress onthe specimen to remain unchanged during the freeze-thawp

35、rocedures.7. Test Specimens7.1 SizeThe size of the specimen depends on the type andsize of permeameter being used for the hydraulic conductivitytesting. The specimen shall have a minimum diameter of 71.1mm (2.80 in.) or greater and a minimum height of 71.1 mm.The height and diameter of the specimen

36、shall be measured to5McManus, A. C., Werthman, P. H., and McManus, K. R., “Evaluation of theEffects of Frost Action on the Permeability of a Compacted Soil,” presented at theNew York State Association of Solid Waste Management Fall Program, LakeLuzerne, NY, October 1989.D6035082the nearest 0.3 mm (0

37、.01 in.) or better. The length and diametershall not vary by more than 65 %. For specimen diameters of71.1 mm, clods less than 12.7 mm (0.5 in.) shall not bereduced. For specimen diameters of 101.6 mm (4.00 in.), clodsizes less than 17.0 mm (0.67 in.) shall not be reduced. Thesurface of the test spe

38、cimen may be uneven, but indentationsmust not be so deep that the length or diameter of the specimenvaries by more than 65 %. The diameter and height of thespecimen shall each be at least 6 times greater than the largestparticle size within the specimen. After completion of the testmethod, if oversi

39、zed particles are found, it should be noted inthe report.7.2 Intact or laboratory-compacted specimens can be usedwith this methodology. Test Method D 5084 shall be followedto prepare intact or laboratory-compacted specimens.7.3 Number of Test SpecimensThis test method providesTest Method A and Test

40、Method B for performing the test.7.3.1 Test Method AA specimen shall be prepared foreach hydraulic conductivity determination performed. Forexample, if the hydraulic conductivity is performed initially,after 5 cycles and finally after 10 freeze-thaw cycles, a total of3 specimens would be required. O

41、ne specimen would be usedfor the initial hydraulic conductivity, the second specimenhydraulic conductivity would be determined after subjectingthe specimen to 5 freeze-thaw cycles and the third specimenhydraulic conductivity would be determined after subjectingthe specimen to 10 freeze-thaw cycles.

42、This test methodrequires similar specimen preparation methods to ensure thatrepresentative samples are used (see Note 4).7.3.2 Test Method BOne specimen can be used for theentire test method. This is not recommended for specimenswith initial moisture contents significantly lower than 100 %saturation

43、 of the soil (Note 4).NOTE 4Using more than one specimen offers the advantage ofcomparison of hydraulic conductivities at an unchanging moisture con-tent. When using one specimen for the entire test, the initial hydraulicconductivity test saturates the specimen producing a specimen for thefreeze-tha

44、w cycles that has a moisture content increased from the originalcompacted moisture content. This test method allows either procedure;however cautions the user about the moisture content. The results shouldnot be significantly different if the initial moisture content is almost atsaturation, which is

45、 the case if soils are compacted well above optimummoisture content. Using more than one specimen for the test method,specifically undisturbed specimens, has the disadvantage of potentialnonrepresentative specimens and test results that are not comparable.7.3.3 Intact SpecimensIntact test specimens

46、shall be pre-pared from a representative portion of intact specimens securedin accordance with Practice D 1587 or Practice D 2113, andpreserved and transported in accordance with requirements forGroup C materials in Practice D 4220 (refer to Test MethodD 5084 for further discussion).7.3.4 Laboratory

47、 Compacted SpecimensRefer to TestMethod D 5084. Specimens shall be compacted in a mold orpiece of PVC pipe or any other suitable apparatus so that thesamples are confined during the freeze-thaw cycles.The user ofthe test method can perform 1-d freeze-thaw by placinginsulation around the pipe and usi

48、ng a control sample with athermocouple (see Note 5) or can perform 3-d freezing byplacing the pipe in the freezer without insulation.7.4 Other preparation test methods can be followed ifspecified and if identified in the report.7.5 Determine the water content (Test Method D 2216),height, diameter, a

49、nd mass of each test specimen and calculatethe dry unit weight. The initial degree of saturation can beestimated.8. Procedure8.1 Determine the initial hydraulic conductivity of thespecimen following Test Method D 5084.8.2 Place the specimen in the freezing cabinet for approxi-mately 24 h (Note 5).The water content of the specimen shouldnot be allowed to change during the freeze-thaw cycles. Thiscan be accomplished by placing each specimen in a plastic bag,or wrapping the specimens in saran wrap.8.3 After 24 h, remove the specimen from the freezingcabinet and p