1、Designation: D 5890 06Standard Test Method forSwell Index of Clay Mineral Component of GeosyntheticClay Liners1This standard is issued under the fixed designation D 5890; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、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 an index method that enablesthe evaluation of swelling properties of a clay mineral inreagent
3、 water for estimation of its usefulness for permeabilityor hydraulic conductivity reduction in geosynthetic clay liners(GCL).1.2 It is adapted from United States Pharmacopeia (USP)test method for bentonite.1.3 Powdered clay mineral is tested after drying to constantweight at 105 6 5C; granular clay
4、mineral should be groundto a 100 % passing a 100 mesh U.S. Standard Sieve with aminimum of 65 % passing a 200 mesh U.S. Standard Sieve.The bentonite passing the 100 mesh U.S. Standard Sieve isused for testing after drying to constant weight at 105 6 5C.1.4 The values stated in SI units are to be reg
5、arded as thestandard.1.5 his standard does not purport to address all of the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use
6、. Specific precautionary statements aregiven in Section 7.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 4643 Test Method for Determination of Water (Moisture)Content of Soil by the Microwave Oven MethodD 4753 Guide for Evaluating, Selecting, and SpecifyingBalance
7、s and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingE1 Specification for ASTM Liquid-in-Glass ThermometersE 145 Specification for Gravity-Convection And Forced-Ventilation OvensE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method
8、E 725 Test Method for Sampling Granular Carriers andGranular Pesticides2.2 United States Pharmacopeia Standard:USP-NF-XVII Bentonite33. Terminology3.1 Definitions:3.1.1 geosynthetic, na planar product manufactured frompolymeric material used with soil, rock, earth, or other geo-technical engineering
9、 related material as an integral part of aman-made project, structure, or system.3.1.2 geosynthetic clay liner, na factory manufacturedhydraulic barrier consisting of clay supported by geotextiles, orgeomembranes, or both, that are held together by needling,stitching, or chemical adhesives.3.1.3 moi
10、sture content, nthat part of the mass of ageosynthetic clay liner that is absorbed water, compared to themass of dry clay.3.1.4 oven-dried, adjthe condition of a material that hasbeen heated under prescribed conditions of temperature andhumidity until there is no further significant change in its ma
11、ss.4. Significance and Use4.1 Clay mineral is a major functional component of GCLsystems that reduces the hydraulic conductivity of industrial,waste, or ground water through the liner.4.2 Clay mineral quality can vary significantly and effect thehydraulic conductivity of the GCL composite. This test
12、 methodevaluates a significant property of clay mineral that relates toperformance.5. Apparatus5.1 Mortar and Pestle or Laboratory Hammer Mill, forgrinding clay mineral to required particle sizing.5.2 U.S. Standard Sieve, 100 mesh, 200 mesh, and auto-mated sieve shaker.5.3 Drying Oven, thermostatica
13、lly controlled, preferablyforced draft type, meeting requirements of Specification E 1451This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.04 on Geosyn-thetic Clay Liners.Current edition approved Jan. 1, 2006. Publis
14、hed February 2006. Originallyapproved in 1995. Last previous edition approved in 2002 as D 5890 - 02.2For 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 D
15、ocument Summary page onthe ASTM website.3Available from U.S. Pharmacopeia (USP), 12601 Twinbrook Pkwy., Rockville,MD 20852.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.and capable of maintaining a uniform temperature of 105 65C th
16、roughout the drying chamber.5.4 Desiccator, of suitable size containing indicator silicagel. It is preferable to use desiccant which changes color toindicate when it needs reconstitution.5.5 Laboratory Balance, 100-g capacity, 60.01-g accuracyand precision.5.6 Weighing Paper, or small weighing dish.
17、5.7 Glass Cylinder, graduated TC (to contain), Class Avolumetrically calibrated, with 1-mL subdivisions and groundglass stopper, high form with approximately 180-mm heightfrom inside base to 100-mL mark.5.8 Wash Bottle, for dispensing reagent water.5.9 Spatula, flat-blade, to dispense clay mineral p
18、owder intocylinder; vibrating spatula should not be used since thedelivery quantity may not be adequately controlled.5.10 Mechanical Ten-Minute Timer.5.11 ASTM Calibration Immersion Thermometer, (Specifi-cation E1).5.12 Drying Oven, thermostatically-controlled, preferablyof the forced-draft type, me
19、eting the requirements of Specifi-cation E 145 and capable of maintaining a uniform temperatureof 105 6 5C throughout the drying chamber.5.13 Microwave OvenA microwave oven, preferably witha vented chamber, is suitable. The required size and powerrating of the oven is dependent on its intended use.
20、Ovens withvariable power controls and input power ratings of about 700W have been found to be adequate for this use. Variable powercontrols are important and reduce the potential for over heatingthe test specimen.NOTE 1Microwave ovens equipped with built-in scales and computercontrols have been deve
21、loped for use in drying soils. Their use iscompatible with this test method.5.14 BalancesAll balances must meet the requirements ofSpecification D 4753 and this section. A Class GP1 balance of0.01 g readability is required for samples having a mass of upto 200 g (excluding mass of sample container).
22、5.15 Sample Containers, suitable containers made of mate-rial resistant to corrosion and change in mass upon repeatedheating, cooling, exposure to materials of varying pH, andcleaning. Microwave sample containers should be microwavesafe.5.16 Desiccator, a desiccator cabinet or large desiccator jarof
23、 suitable size containing indicator silica gel. It is preferable touse a desiccant that changes color to indicate it needs recon-stitution.5.17 Container Handling Apparatus, gloves, tongs, or suit-able holder for moving and handling hot containers afterdrying.6. Reagents6.1 Purity of ReagentsUnless
24、otherwise indicated, refer-ences to water shall be understood to mean reagent waterconforming to Specification D 1193, Type I, II, or III (see TableX1.1). Such water is best prepared by distillation or the passageof tap water through an ion exchange resin.6.2 Specification D 1193 for reagent water,
25、Type I, II, or III(see Table X1.1).7. Hazards7.1 Handle hot containers with a container holder.7.2 Safety precautions supplied by the manufacturer of themicrowave/oven should be observed.7.3 Do not use metallic containers in a microwave oven (ifused).8. Sampling and Selection8.1 Carry out sampling i
26、n accordance with Test MethodE 725.9. Procedure9.1 Grind the clay mineral sample to 100 % passing a 100mesh U.S. Standard Sieve and a minimum of 65 % passing a200 mesh U.S. Standard Sieve with a mortar and pestle orlaboratory hammer mill as required.9.2 The container to be used for drying should be
27、oven driedthoroughly and subsequently placed into a desiccator untilready for use so that the tare weight of the container will berecorded.9.3 Determine and record the tare of the specimen container.9.4 Select representative test specimens.9.5 Place the test specimen in the individual container.Dete
28、rmine the mass of the container and clay specimen asdelivered using a balance selected on the basis of the samplemass. Record the value of the clay specimen.NOTE 2To prevent mixing of samples and yielding of incorrectresults, all containers should be numbered and the container numbers shallbe record
29、ed on the laboratory data sheets.9.6 Place the container with the clay specimen in the dryingoven. Dry the clay specimen to a constant mass. Maintain thedrying oven at 105 6 5C. The time required to obtain constantmass will vary depending on the type of material, oven typeand capacity, and other fac
30、tors.NOTE 3In most cases, drying a test sample overnight (about 12 to 16h) is sufficient for conventional ovens. In cases where there is doubtconcerning the adequacy of drying, drying should be continued until thechange in mass after two successive periods (greater than 1 h) of dryingis less than 0.
31、1 %. In this case it should be verified that excessive dryingdoes not influence the swelling performance of the clay. This can be donei.e. by comparing the swelling values after the first drying period (about12 to 16 h) and the swelling values of bentonite being dried for a longertime period.NOTE 4I
32、f a microwave oven is used to dry the test specimen(s), theuser of this test method should follow the drying procedures as stated inTest Method D 4643. It is also recommended that the total mass of the testspecimen(s) be a minimum of 100 g. It is further recommended to run acomparison test between t
33、he microwave oven and the drying oven todemonstrate that the microwave oven gives similar values as the dryingoven and that excessive drying does not change the swelling performanceof the clay.NOTE 5Since some dry materials may absorb moisture from moistsamples, dried samples should be removed befor
34、e placing moist samplesin the same oven. However, this would not be applicable if the previouslydried specimens will remain in the drying oven for an additional timeperiod of about 16 h.9.7 After the material has dried to constant mass, removethe container from the oven (and replace the lid if used)
35、. Allowthe material and container to cool to room temperature in aD5890062desiccation unit or until the container can be handled comfort-ably with bare hands and the operation of the balance will notbe affected by convection currents or its being heated, or both.Determine the mass of the container a
36、nd oven-dried materialusing the same balance as used previously. Subtract the tare ofthe container from the mass of the sample to determine thesamples constant dry mass. Record this value.9.8 Weigh 2.00 6 0.01 g of dried and finely ground claymineral onto a weighing paper.9.9 Add 90 mLreagent water
37、to the clean 100-mLgraduatedcylinder.9.10 Remove not more than a 0.1-g increment of claymineral with a volumetric spoon from weighing dish or paperand carefully dust it over the entire surface of water in thegraduated cylinder over a period of approximately 30 s. Do notuse a funnel that may concentr
38、ate the clay mineral in a poorlyhydrated agglomerate. Allow the clay mineral to wet, hydrate,and settle to the bottom of the graduated cylinder for aminimum period of 10 min.9.11 Add additional increments of the clay mineral powderin periods of 10 min, allowing the clay mineral to swell withoutair b
39、eing trapped in between, following the details in 9.10, untilthe entire 2.00-g sample has been added.9.12 After the final increment has settled, carefully rinse anyadhering particles from the sides of the cylinder into the watercolumn, raising the water volume to the 100 mL mark.9.13 Place the glass
40、 stopper on the cylinder and allow it tostand undisturbed for a minimum of 16 h from the lastincremental addition. After 2 h, inspect the hydrating claymineral column for trapped air or water separation in thecolumn. If present, gently tip the cylinder at a 45 angle androll slowly to homogenize the
41、settled clay mineral mass, allowthe graduated cylinder with the hydrating clay mineral toremain undisturbed for a minimum of 16 h before recording thevolume of the hydrated clay mass and its temperature.9.14 After the minimum 16-h hydration period from the lastincrement addition, record the volume l
42、evel in millilitres (mL)at the top of the settled clay mineral to the nearest 0.5 mL.Observe the distinct change in appearance at the upper surfaceof the settled clay mineral. Any low-density flocculated mate-rial (sometimes lighter in coloration to white) shall be ignoredfor this measurement. Recor
43、d the observed volume of hydratedclay mineral.NOTE 6OptionalIf a recognizable swelling still occurs after theminimum hydration period from the last increment addition (more than10 % of the previous reading in a 4 hour period), continue recording thevolume of the hydrated clay mass and its temperatur
44、e to a maximum of 48hours after the last increment addition.9.15 Carefully immerse the thermometer and measure thetemperature of the slurry. Record the temperature of thehydrated clay mineral to 60.5C.10. Report10.1 Report the following information:10.1.1 Source of clay mineral, including sample ide
45、ntifica-tion or lot number,10.1.2 Method of sampling used,10.1.3 ASTM standard test method number used to performthe test,10.1.4 Any modifications to the test method or unusualobservations which may effect the test results, and10.1.5 Swell index as mL/2 g to the nearest 0.5 mL after theminimum 16-h
46、hydration period from the last clay incrementaddition and if applicable to the maximum recorded hydrationperiod from the last clay increment addition.11. Precision and Bias11.1 Interlaboratory Test ProgramAn interlaboratorystudy of the test method was run in 1999. The design of theexperiment, simila
47、r to that of Practice E 691. Seven differentclay mineral samples were distributed to ten laboratories.Three sets of test results were generated for each sample byeach of the laboratories.11.2 Test ResultsThe precision information is given inTable 1. The average swell index values ranged from 20 to 3
48、6for the seven clay mineral samples tested. However, since thestatistics were not related to the magnitude of the test result, theprecision values have been presented in terms of coefficients ofvariation, CV %.11.3 BiasThe procedure in Test Method D 5890 for mea-suring the swell index of clay minera
49、l component of geosyn-thetic clay liners has no bias because the values of swell indexcan be defined only in terms of this test method.12. Keywords12.1 bentonite; clay; geosynthetic clay liner; microwave;oven drying; swell; swell indexTABLE 1 Test ResultsStatistic ILS RangeWithin laboratory repeatability limit, CV %r2to5%Between laboratory reproducibility limit, CV %R7to22%95 % confidence limitWithin laboratory repeatability, 2.8 CV %r6to14%95 % confidence limitBetween laboratory reproducibility, 2.8 CV %R20 to 61 %D5890063APPENDIXX1. Additional Reagent Informa
