1、Designation: D4943 08Standard Test Method forShrinkage Factors of Soils by the Wax Method1This standard is issued under the fixed designation D4943; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe
2、r in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.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 beu
3、sed to calculate shrinkage ratio, volumetric shrinkage, andlinear shrinkage.1.3 This 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 t
4、he properties of thesample as a whole must be considered when using theseprocedures 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 Swedis
5、hsoil scientist, A. Atterberg. These limits distinguish the bound-aries of the several consistency states of cohesive soils.1.6 All recorded and calculated values shall conform to theguide for significant digits and rounding established in PracticeD6026.1.6.1 The procedures used to specify how data
6、are collected/recorded and calculated in this standard are regarded as theindustry standard. In addition, they are representative of thesignificant digits that should generally be retained. The proce-dures used do not consider material variation, purpose forobtaining the data, special purpose studie
7、s, or any consider-ations for the users objectives; and it is common practice toincrease or reduce significant digits of reported data to becommensurate with these considerations. It is beyond the scopeof this standard to consider significant digits used in analysismethods for engineering design.1.7
8、 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.8 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-p
9、riate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific safetyhazards, see Section 7 and Note 4.2. Referenced Documents2.1 ASTM Standards:2C670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Materi
10、alsC702 Practice for Reducing Samples ofAggregate to TestingSizeD75 Practice for Sampling AggregatesD420 Guide to Site Characterization for Engineering Designand Construction Purposes (Withdrawn 2011)3D653 Terminology Relating to Soil, Rock, and ContainedFluidsD854 Test Methods for Specific Gravity
11、of Soil Solids byWater PycnometerD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4318 Test Methods for Liquid Limit, Plastic Limit, andPlasticity Index of SoilsD4753 Guide for Evaluating, Selectin
12、g, and Specifying Bal-ances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD6026 Practice for Using Significant Digits in GeotechnicalDataE2251 Specification for Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision LiquidsE11 Specification for Woven Wire Test Sie
13、ve Cloth and TestSieves3. Terminology3.1 DefinitionsAll definitions are in accordance with Ter-minology D653.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.03 on Texture, Plasticityand Density Characteristics of S
14、oils.Current edition approved June 1, 2008. Published July 2008. Originally approvedin 1989. Last previous edition approved in 2002 as D4943 02. DOI: 10.1520/D4943-08.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual
15、Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor
16、 Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesNOTICE: This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International (www.astm.org) for the latest information14. Summary of Test Method4.1 A sample of fine-grained soil is thoroughl
17、y remoldedwith water to form a paste that is at approximately the liquidlimit consistency. This paste is used to fill a small dish to forma soil pat. The initial moisture content of the wet soil pat isdetermined. The soil pat is slowly dried to constant mass. Thevolume of the dry soil is determined
18、using a water submersiontechnique.Acoating of wax is used to prevent water absorptionby the dry soil pat. Then the moisture-content loss to dry thesoil to a constant volume is determined and subtracted from theinitial moisture content to calculate the shrinkage limit. Themeasurements are used to com
19、pute the soil constants.5. Significance and Use5.1 The term shrinkage limit, expressed as a moisturecontent in percent to the nearest whole number, represents theamount of water required just to fill all of the voids of a givencohesive soil at its minimum void ratio obtained by ovendry-ing. The shri
20、nkage limit can be used to evaluate the shrinkagepotential, crack development potential, and swell potential ofearthwork involving cohesive soils.NOTE 1The quality of the result produced by this standard isdependent on the competence of the personnel performing it, and thesuitability of the equipmen
21、t and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/inspection/and the like. Users of thisstandard are cautioned that compliance with Practice D3740 does not initself assure reliable results. Reliable res
22、ults depend on many factors;Practice D3740 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 requirements ofSpecification D4753 for a balance of 0.01-g readability.6.2 Suspension Apparatus (opti
23、onal)A device centered onthe balance suitable for suspending the soil specimen in acontainer of water located next to or below the balance orscale.6.3 Dish, ShrinkageA circular porcelain or monel metalmilk dish having a flat bottom about 40 to 45 mm in diameterand about 12 to 15 mm deep.6.4 Drying O
24、venAn oven, thermostatically controlled,preferably of the forced draft type, and capable of maintaininga uniform temperature of 110 6 5C throughout the dryingchamber.6.5 Humidity Enclosure (optional)Small closed containerlarge enough for shrinkage dishes and a small container ofwater used in dry cli
25、mates to slow the initial rate of drying.6.6 Mortar and PestleMortar, iron or porcelain, about 125to 150-mm diameter with rubber tipped pestle.6.7 SpatulaA spatula or pill knife having a blade about100 mm long by about 20 mm wide.6.8 StraightedgeA stiff metal straightedge of convenientlength. The sc
26、raping edge must be beveled if it is thicker than3 mm.6.9 SieveU.S.A. Standard series No. 40 (425-m) sieveconforming to the requirements of Specification E11.6.10 WaxMicrocrystalline or other suitable wax mixturewhich is not brittle when dry and does not shrink duringsolidification. Sufficient quant
27、ity when melted in the waxwarmer to submerge the soil pat.NOTE 2A 50/50 mixture of paraffin wax and petroleum jelly willprovide an adequate alternative.6.11 Sewing ThreadFine thread to hold the specimen todip into the wax.6.12 Water, distilled.6.13 Water BathOf sufficient size (for example, 250 mLbe
28、aker) to submerge the soil pat when determining indicatedmass in water.6.14 Wax WarmerSufficient temperature control to avoidoverheating.6.15 Thermometer (optional)A thermometer, in the roomtemperature range, 0.5 gradations, conforming to the require-ments of Specification E2251.6.16 Glass or Clear
29、Plastic Plate, used for calibrating theshrinkage dish, about 80 by 80 mm, about 5 mm thick.6.17 Petroleum Base Lubricant, used to grease the shrink-age dish.6.18 Liquid Limit Device and Grooving Tool, as described inTest Method D4318.7. Safety Hazards7.1 Wax melting equipment or hot wax may burn unp
30、ro-tected skin. Overheated wax may burst into flames; therefore,extreme care should 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 C702 and D75, as well as GuideD420, as
31、guides for selecting and preserving samples fromvarious types of sampling operations.8.2 Where sampling operations have preserved the naturalstratification of a sample, keep the various strata separated andperform tests on the particular stratum of interest with as littlecontamination as possible fr
32、om other strata. Where a mixtureof materials will be used in construction, combine the variouscomponents in such proportions that the resultant samplerepresents the actual construction case.8.3 Where data from this test method are to be used forcorrelation with other laboratory or field test data, u
33、se the samematerial as used for these tests where possible.8.4 Obtain a representative 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
34、mass by making one or more sweeps with a scoop throughthe mixed mass.9. Calibration and Standardization9.1 Calibrate each shrinkage dish used in accordance withAnnex A1. Since the dishes may have different volumes, eachdish must be permanently identified.D4943 0829.2 The specific gravity (or density
35、) of the wax must beknown in advance to at least two significant digits. This canusually be obtained from the manufacturer. If not, determinethe specific gravity in accordance with Annex A2. In eithercase, the specific gravity value should be checked initially andthen periodically.9.3 Maintain the w
36、ater bath, testing apparatus, and thelaboratory environment at about the same temperature whileperforming both the dish calibrations and the individual testmeasurement. Temperature differences as large as 5C will notadversely impact the shrinkage limit when reported to thenearest whole number.10. Pr
37、eparation of Test Specimen10.1 Prepare the test specimen in accordance with thedirections in Test Method D4318, using either the wet or drypreparation procedure, except that the moisture content of thesoil is adjusted to a consistency that would require about tenblows of the liquid limit device to c
38、lose the groove along adistance of 13 mm. The amount of water required may exceedthe liquid limit by as much as 10 percentage points.11. Procedure11.1 Select a shrinkage dish and record its identificationdesignation and its volume (V). The volume of the shrinkagedish is used as the volume of the wet
39、 soil pat. Lightly greasethe inside 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 (m).11.3 Place, in the center of the dish, an amount of the wettedsoil equal to about one-third the volume of the dish and cause
40、the 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 has been brought to the surfa
41、ce. 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 after it isfilled and record
42、the struck measure value as the mass of dishplus wet soil pat (mw).11.5 Allow the soil pat to dry in air until the color of the patturns from dark to light.11.5.1 Drying the soil pat in air may produce cracking of thesoil pat due to rapid moisture loss. This is a concern in dryclimates. If this prob
43、lem is encountered, slow the rate ofmoisture loss by drying the soil pat in a humidity controlledenvironment.NOTE 3The time required to air dry the soil pat will depend on theplasticity of the soil, the initial water content, and the relative humidity. Insome cases it may take from 1 to 2 weeks for
44、the color of the soil to turnfrom dark to light.11.6 Oven dry the soil pat to constant mass at 110 6 5C.11.7 Determine and record the mass of dish plus dry soil pat(md).11.8 Coat the dry soil pat with wax as follows:11.8.1 Securely tie the sewing thread (about 30 cm long isadequate) around the soil
45、pat.11.8.2 Immerse the dry soil pat in molten wax, holding thedry pat with the sewing thread, completely coating the pat. Usea continuous motion into and immediately out of the wax. Theimmersion should only take a few seconds. Do not allow airbubbles to develop in the wax coating. If air bubbles are
46、present, use a sharp object to cut out the bubble; refill the holewith wax. Repeat the dipping process two or three times tocreate a smooth wax coating.NOTE 4Precaution: The melted wax and associated equipment arehot and care should be exercised to avoid burns.11.8.3 Allow the wax coating and soil p
47、at to cool to roomtemperature.11.9 Determine the mass of the wax-coated pat of soil in airand record the value as the mass in air of the dry soil and wax(msxa).11.10 Determine the mass of water displaced by thesubmerged wax-coated pat using either Section 11.10.1 or11.10.2. Make sure that there are
48、no air bubbles clinging to thesurface of the wax-coated pat or thread during this measure-ment.11.10.1 Record the mass indicated when the wax-coated patof soil is suspended from a hanger placed on the balance orscale while submerged in a water bath. This is the indicatedmass in water of the dry soil
49、 pat and wax (msxw).11.10.2 Record the mass indicated when the wax-coated patof soil is submerged in a water bath placed on the balance orscale while suspended from a hanger separate from the balanceor scale. This is the mass of water displaced by the dry soil patand wax (mwsx).NOTE 5There 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 dry soil pat, g,md= mass of the dry soi
