ASTM D4943-2002 Standard Test Method for Shrinkage Factors of Soils by the Wax Method《用蜂蜡法对土壤收缩系数的标准试验方法》.pdf

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1、Designation: D 4943 02Standard Test Method forShrinkage Factors of Soils by the Wax Method1This standard is issued under the fixed designation D 4943; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num

2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONGiven the concern that mercury is a hazardous substance, this test method is offered as an alternativeto Test Method D 427, which is used

3、 to determine the shrinkage limit and other shrinkage factors ofsoils using mercury (see Caution statement in Test Method D 427). Since this test method has beenperformed by only a few organizations to date, others are encouraged to perform both test methods andto report their findings to Subcommitt

4、ee D18.03. (See Appendix X1 for a rationale of this test method.)1. Scope *1.1 This test method covers the procedure for determiningthe shrinkage limit of soils.1.2 The data obtained using this test method may also beused to calculate shrinkage ratio, volumetric shrinkage, andlinear shrinkage.1.3 Th

5、is test method is applicable only for cohesive soils.1.4 Since this test method is performed only on that portionof a soil which passes the No. 40 (425-m) sieve, the relativeconsistency of this portion of the soil to the properties of thesample as a whole must be considered when using theseprocedure

6、s to evaluate the properties of a soil.1.5 The shrinkage limit along with the liquid limit andplastic limit of soils are often collectively referred to as theAtterberg limits in recognition of their formation by Swedishsoil scientist, A. Atterberg. These limits distinguish the bound-aries of the sev

7、eral consistency states of cohesive soils.1.6 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of

8、the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific safetyhazards, see Section 7, Note 2, and Note X1.1.2. Referenced Documents2.1 ASTM Standards:C 670 Practice for Preparing Precision a

9、nd Bias Statementsfor Test Methods for Construction Materials2C 702 Practice for Reducing Samples of Aggregate toTesting Size2D 75 Practice for Sampling Aggregates3D 420 Guide to Site Characterization for Engineering, De-sign, and Construction Purposes4D 427 Test Method for Shrinkage Factors of Soil

10、 by theMercury Method4D 653 Terminology Relating to Soil, Rock, and ContainedFluids4D 854 Test Method for Specific Gravity of Soils4D 2726 Test Method for Bulk Specific Gravity and Densityof Compacted Bituminous Mixtures Using SaturatedSurface-Dry Specimens3D 3740 Practice for Agencies Engaged in th

11、e Testing and/orInspection of Soil and Rock as Used Ingineering Designand Construction4D 4318 Test Method for Liquid Limit, Plastic Limit, andPlasticity Index of Soils4D 4753 Specification for Evaluating, Selecting, and Speci-fying Balances and Scales for Use in Soil, Rock, andRelated Construction M

12、aterials4E 1 Specification for ASTM Thermometers5E 11 Specification for Wire-Cloth Sieves for Testing Pur-poses63. Terminology3.1 DefinitionsAll definitions are in accordance with Ter-minology D 653.1This test method is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct r

13、esponsibility of Subcommittee D18.03 on Texture, Plasticityand Density Characteristics of Soils.Current edition approved July 10, 2002. Published September 2002. Originallypublished as D 4943 89. Last previous edition D 4943 95.2Annual Book of ASTM Standards, Vol 04.02.3Annual Book of ASTM Standards

14、, Vol 04.03.4Annual Book of ASTM Standards, Vol 04.08.5Annual Book of ASTM Standards, Vol 14.03.6Annual Book of ASTM Standards, Vol 14.02.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2

15、959, United States.4. Summary of Test Method4.1 The moisture content of a pat of wet soil is determined.Then the moisture-content loss to dry the soil to a constantvolume is determined and subtracted from the initial moisturecontent to calculate the shrinkage limit. The volume of the drysoil pat is

16、determined from its mass in air and its indicatedmass when submerged in water. A coating of wax is used toprevent water absorption by the dry soil pat.5. Significance and Use5.1 The term shrinkage limit, expressed as a moisturecontent in percent, represents the amount of water required justto fill a

17、ll of the voids of a given cohesive soil at its minimumvoid ratio obtained by ovendrying. The shrinkage limit can beused to evaluate the shrinkage potential, crack developmentpotential, and swell potential of earthwork involving cohesivesoils.NOTE 1The quality of the result produced by this standard

18、 isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D 3740 are generally considered capable of competentand objective testing/sampling/inspection/and the like. Users of thisstandard are cau

19、tioned that compliance with Practice D 3740 does not initself assure reliable results. Reliable results depend on many factors;Practice D 3740 provides a means of evaluating some of those factors.6. Apparatus6.1 Balance or ScaleA balance or scale having a mini-mum capacity of 500 g and meeting the r

20、equirements ofSpecification D 4753 for a balance of 0.01-g readability. Thebalance or scale shall be equipped with suitable apparatus forsuspending the soil specimen in water from the center of theplatform or pan.6.2 Dish, ShrinkageA circular porcelain or monel metalmilk dish having a flat bottom ab

21、out 40 to 45 mm in diameterand about 12 to 15 mm deep.6.3 Drying OvenAn oven, thermostatically controlled,preferably of the forced draft type, and capable of maintaininga uniform temperature of 110 6 5C throughout the dryingchamber.6.4 Mortar and PestleMortar, iron or porcelain, about 125to 150-mm d

22、iameter with rubber tipped pestle.6.5 SpatulaA spatula or pill knife having a blade about100 mm long by about 20 mm wide.6.6 StraightedgeA stiff metal straightedge of convenientlength. The scraping edge must be beveled if it is thicker than3 mm.6.7 SieveU.S.A. Standard series No. 40 (425-m) sievecon

23、forming to the requirements of Specification E 11.6.8 Microcrystalline WaxSufficient quantity to cover thesoil pat.6.9 Sewing ThreadFine thread to hold the specimen to dipinto the wax.6.10 Water, Distilled.6.11 Water BathOf sufficient size to allow the soil pat tobe submerged when determining mass i

24、n water.6.12 Wax WarmerSufficient temperature control to avoidoverheating.6.13 Thermometer (optional)A thermometer, 0 to 50Crange, 0.5 gradations, conforming to the requirements ofSpecification E 1.6.14 Glass or Clear Plastic Plate, used for calibrating theshrinkage dish, about 80 by 80 mm, about 5

25、mm thick.6.15 Petroleum Base Lubricant, used in calibrating theshrinkage dish.6.16 Liquid Limit Device and Grooving Tool, as described inTest Method D 4318.7. Safety Hazards7.1 Wax melting equipment or hot wax may burn unpro-tected skin. Overheated wax may burst into flames; therefore,extreme care s

26、hould be taken when working with hot wax. Donot use an open flame device to heat wax.8. Sampling8.1 Take samples from any location that satisfies testingneeds. However, use Practices C 702 and D 75, as well asGuide D 420, as guides for selecting and preserving samplesfrom various types of sampling o

27、perations.8.2 Where sampling operations have preserved the naturalstratification of a sample, keep the various strata separated andtests performed on the particular stratum of interest with aslittle contamination as possible from other strata. Where amixture of materials will be used in construction

28、, combine thevarious components in such proportions that the resultantsample represents the actual construction case.8.3 Where data from this test method are to be used forcorrelation with other laboratory or field test data, use the samematerial as used for these tests where possible.8.4 Obtain a r

29、epresentative portion from the total samplesufficient to provide 150 to 200 g of material passing the No.40 (425-m) sieve. Mix samples thoroughly in a pan with aspatula or scoop and scoop a representative portion from thetotal mass by making one or more sweeps with a scoop throughthe mixed mass.9. C

30、alibration and Standardization9.1 Calibrate each shrinkage dish used in accordance withAnnex A1. Since the dishes may have different volumes, eachdish must be permanently identified.9.2 The specific gravity (or density) of the microcrystallinewax must be known in advance. This can usually be obtaine

31、dfrom the manufacturer. If not, determine the specific gravity inaccordance with Test Method D 2726. In either case, thespecific gravity value should be checked initially and thenperiodically.9.3 Maintain the water bath, testing apparatus, and thelaboratory environment at about the same temperature

32、whileperforming this procedure.10. Preparation of Test Specimen10.1 Prepare the test specimen in accordance with thedirections in Test Method D 4318, using either the wet or drypreparation, except that the moisture content of the soil isadjusted to a consistency that would require about ten blows of

33、the liquid limit device to close the groove along a distance of13 mm. The amount of water required may exceed the liquidlimit by as much as 10 percentage points.D494302211. Procedure11.1 Select a shrinkage dish and record its identificationdesignation and its volume. The volume of the shrinkage dish

34、is used as the volume of the wet soil pat. Lightly grease theinside of the shrinkage dish.11.2 Determine the mass of the greased shrinkage dish andrecord the value as the mass of the empty shrinkage dish.11.3 Place, in the center of the dish, an amount of the wettedsoil equal to about one-third the

35、volume of the dish and causethe soil to flow to the edges by tapping the dish on a firmsurface cushioned by several layers of blotting paper or similarmaterial. Add an amount of soil approximately equal to the firstportion, and tap the dish until the soil is thoroughly compactedand all included air

36、has been brought to the surface. Add moresoil and continue the tapping until the dish is completely filledand excess soil stands out about its edge. Strike off the excesssoil with a straightedge and wipe off all soil adhering to theoutside of the dish.11.4 Determine the mass of the dish immediately

37、after it isfilled and record the struck measure value as the mass of dishplus wet soil.11.5 Allow the soil pat to dry in air until the color of the patturns from dark to light. Oven dry the pat to constant mass at110 6 5C. Determine and record the mass of dish plus drysoil.11.5.1 Drying the soil pat

38、 in air may produce cracking of thesoil due to rapid moisture losses in dry climates. If this problemis encountered, it may be necessary to dry the soil in a humiditycontrolled environment. In this case, it may take from 1 to 2weeks for the color of the soil to turn from dark to light.11.6 Determine

39、 the volume of the dry soil pat as follows:11.6.1 Securely tie the sewing thread around the soil pat.11.6.2 Immerse the dry pat of soil in molten wax, holdingthe dry pat with the sewing thread, completely coating the pat.Do not allow air bubbles to develop in the wax coating. If airbubbles are prese

40、nt, use a sharp object to cut out the bubble;refill the hole with wax.NOTE 2Precaution: The melted wax and associated equipment arehot and care should be exercised to avoid burns.11.6.3 Remove the pat of soil from the melted wax andallow the wax coating to cool.11.6.4 Determine the mass of the wax-c

41、oated pat of soil inair and record the value as the mass in air of the dry soil andwax.11.6.5 Determine the mass indicated when the wax-coatedpat of soil is suspended from a balance while submerged in awater bath. Make sure that there are no air bubbles clinging tothe surface of the wax-coated pat o

42、r thread. Record this as themass in water of the dry soil and wax.NOTE 3There are other acceptable methods of determining theindicated difference of the mass of the soil pat in air and in water.12. Calculation12.1 Calculate the mass of the dry soil pat as follows:ms5 md2 m (1)where:ms= mass of the d

43、ry soil pat, g,md= mass of the dry soil pat and shrinkage dish, g, andm = mass of the shrinkage dish, g.12.2 Calculate the moisture content of the soil at the time itwas placed in the dish as follows:w 5Fmw2 md!msG3 100 (2)where:w = moisture content of the soil at the time it was placedin the dish,

44、%, andmw= mass of the wet soil and shrinkage dish, g.12.3 Calculate the volume of the dry soil pat as follows:12.3.1 Calculate the volume of the dry soil pat and wax asfollows:Vdx5msxa2 msxw!rw(3)where:Vdx= volume of dry soil pat and wax, cm3,msxa= mass of dry soil pat and wax in air, g,msxw= indica

45、ted mass of dry soil pat and wax in water, g,andrw= density of water, g/cm3.NOTE 4Assume density of water equal to 1.0 g/cm3. Corrections fortemperature may be used, if desired.12.3.2 Calculate the mass of wax as follows:mx5 msxa2 ms(4)where:mx= mass of wax, g.12.3.3 Calculate the volume of wax as f

46、ollows:Vx5mxGxrvormxrx(5)where:Vx= volume of wax, cm3,Gx= specific gravity of wax, andrx= density of wax, g/cm3.12.3.4 Calculate the volume of dry soil pat as follows:Vd5 Vdx2 Vx(6)where:Vd= volume of dry soil pat, cm3.12.4 Calculate the shrinkage limit as follows:SL 5 w 2FV 2 Vd!rwmsG3 100 (7)where

47、:SL = shrinkage limit, andV = volume of wet soil pat ( = volume of the shrinkagedish), cm3.12.5 If desired, calculate the shrinkage ratio as follows:R 5msVd3rw!(8)where:R = shrinkage ratio.D494302312.6 If desired, calculate the volumetric shrinkage as fol-lows:Vs5 Rw12 SL! (9)where:Vs= volumetric sh

48、rinkage, andw1= some given moisture content,% .12.7 If desired, calculate the linear shrinkage as follows:Ls5 100F1 2S100Vs1 100D1/3G(10)where:Ls= linear shrinkage.13. Report13.1 Report the following information:13.1.1 Sample identifying number.13.1.2 Any special selection process.13.1.3 Report the

49、shrinkage limit to the nearest wholenumber omitting the percent designation.13.1.4 If desired, report the shrinkage ratio, volumetricshrinkage, and linear shrinkage.14. Precision and Bias14.1 PrecisionTable 1 presents estimates of precisionbased on the results from the AASHTO Materials ReferenceLaboratory (AMRL) Proficiency Sample Program of testingconducted on Sample Numbers 113 and 114. These sampleswere found to be a CL material having 95.0 % fines, a liquidlimit of 44, a plastic limit of 22, a shrinkage limit of 14, and ashrinkage ratio of 1.92.14.1.