1、Designation: D4542 15Standard Test Methods forPore Water Extraction and Determination of the Soluble SaltContent of Soils by Refractometer1This standard is issued under the fixed designation D4542; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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. Scope*1.1 These test methods cover a rapid procedure for squeez-ing pore water from finegrained soil
3、s for the purpose ofdetermining the amount of soluble salts present in the extractedpore water.1.2 These test methods were developed for soils having awater content equal to or greater than approximately 14 %, forexample, marine soils. An extensive summary of proceduresfor extracting pore water from
4、 soils has been presented byKriukov and Manheim (1).21.3 These test methods are not generally applicable fordetermining the soluble salt content of the pore water extractedfrom coarse-grained soils, such as clean sands and gravels.1.4 Test Method A provides a procedure using a refracto-meter with a
5、refraction index scale; Test Method B provides aprocedure using a refractometer with a parts per thousand (ppt)scale.1.5 UnitsThe values stated in SI units are to be regardedas the standard.1.6 All observed and calculated values shall conform to theguidelines for significant digits and rounding esta
6、blished inPractice D6026 unless superseded by these test methods.1.6.1 The procedures used to specify how data are collected/recorded and calculated in the standard are regarded as theindustry standard. In addition, they are representative of thesignificant digits that generally should be retained.
7、The proce-dures used do not consider material variation, purpose forobtaining the data, special purpose studies, 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 beyo
8、nd the scopeof these test methods to consider significant digits used inanalysis methods for engineering data.1.7 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-priate safet
9、y and health practices and determine the applica-bility of regulatory limitations prior to use.1.8 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.2. Referenced Documents2.1 ASTM Standards:3D653 Terminology Relating t
10、o Soil, Rock, and ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD6026 Practice for Using Significant Digits in GeotechnicalDataE832 Specification for Laboratory Filter Papers2.2 Fe
11、deral Document:GG-S-945a Specification for Syringe and Needle,Disposable, Hypodermic, Sterile, Single Injection43. Terminology3.1 Definitions:3.1.1 For definitions of common terms in this standard, referto Terminology D653.4. Significance and Use4.1 The soluble salt content may be used to correct th
12、e indexproperties of soils such as water content, void ratio, specificgravity, degree of saturation, and dry density).4.2 Minimize the time period between sampling and testingto reduce chemical changes, which may occur within the soilsample.1This test method is under the jurisdiction ofASTM Committe
13、e D18 on Soil andRock and is the direct responsibility of Subcommittee D18.06 on Physical-ChemicalInteractions of Soil and Rock.Current edition approved Nov. 1, 2015. Published December 2015. Originallyapproved in 1985. Last previous edition approved in 2007 as D4542 07. DOI:10.1520/D4542-15.2The bo
14、ldface numbers in parentheses refer to the list of references appended tothis standard.3For 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 Summar
15、y page onthe ASTM website.4Available from Naval Publications and Forms Center, 5801 Tabor Ave.,Philadelphia, PA, 19120.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1NO
16、TE 1The 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 that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/
17、inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in itself ensurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors.NOTE 2Hulbert and Brindle (2) and Torrance (3) have shown tha
18、tprolonged storage should be avoided as unpredictable and non-reproducible chemical changes may occur.5. Apparatus5.1 RefractometerA temperature compensated refracto-meter scaled to either index of refraction or ppt (parts perthousand). A typical hand held refractometer is shown in Fig.1.5.2 Soil Pr
19、essThe apparatus shall conform to the exampleshown in Fig. 2. It should be constructed from materialappropriate for the application and chemically compatible withthe material being tested.5.3 SyringeA 25-cm3syringe without needle, in accor-dance with Fed. Std. GG-S-945a.5.4 BalanceAbalance capable o
20、f determining mass with areadability of 60.01 g.5.5 Filter Paper:5.5.1 A general purpose quantitative filter paper in accor-dance with Specification E832, Type II, Class F, for mediumcrystalline precipitates in the size range from 5 to 10 m, withan ash content of 0.13 mg/12.5-cm circle. Cut filter p
21、aper to adiameter of 55 mm.5.5.2 A general purpose quantitative filter paper in accor-dance with Specification E832, Type II, Class G, for finecrystalline precipitates in the size range from 0.45 m, with anash content of 0.13 mg/12.5-cm circle. Cut filter paper to adiameter of 25 mm.5.6 Refrigerator
22、Cooling unit capable of maintaining auniform temperature between 1 and 5C.5.7 Micro-Syringe Filter HolderA device to filter a liquiddirectly from a syringe.55.8 100-mL Polyethylene or Glass Bottle and Cap.5.9 Miscellaneous SuppliesDistilled water, alcohol, di-luted HCl (1:10), detergent, and optiona
23、l sterile bags forsample storage (see 8.6).6. Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytic Reagents of the American Chemical Society,where
24、 such specifications are available.66.1.1 Hydrochloric Acid diluted 1:106.1.2 Alcohol6.1.3 Chromic acid6.1.4 Acetone7. Preparation of Apparatus7.1 Wash the parts of the press thoroughly. Rinse twice withdistilled water and dry. Rust should not be present, especiallyinside or around the top of the cy
25、linder. If rust is present, scrubgently with steel wool and soap or chromic acid. Rinse wellwith tap water and then twice with distilled water and dry.7.2 If the press parts have been coated with rust preventer,wash them with alcohol and rinse once with tap water andtwice with distilled water.7.3 Dr
26、y by a method that will not contaminate the press.Clean compressed air, oven or air drying, or rinsing withacetone followed by air drying are acceptable.7.4 Assemble the press.NOTE 3To prevent mud from circumventing the stainless steel wirescreen, use flexible TFE-fluorocarbon gaskets on each side.8
27、. Sampling and Test Specimen Squeezing8.1 Select a representative soil sample of approximately 50g and place into the cylinder on top of a single sheet of 5 to10-m (55-mm) filter paper.8.2 Apply pressure slowly until the first drops of water areexpelled, then insert a clean, disposable, syringe (25
28、mL) in theeffluent passage shown in Fig. 2. This process reduces theamount of air in the syringe and therefore, the amount ofevaporation.8.3 Apply pressure gradually to a maximum of 80 MPa, andhold until no more water is expelled or until the syringe is full(see Note 4 and Note 5).8.4 Withdraw the s
29、yringe when the pressure is at a maxi-mum and immediately expel the fluid from the syringe through5An apparatus such as the stainless steel Millipore Micro-Syringe Filter HolderXX30-025-00 is satisfactory for this purpose.6Reagent Chemicals, American Chemical Society Specifications,” AmericanChemica
30、l Society, Washington, DC. For suggestions on the testing of reagents lotlisted by theAmerica Chemical Society, see “Reagent Chemicals and Standards,” byJoseph Rosin, D. Van Nostrand Co., Inc., New York, NY, and the “United StatesPharmacopeia.”FIG. 1 Typical Hand-Held RefractometerD4542 152a stainle
31、ss steel micro-syringe holder, fitted with fresh 0.45-m(25-mm) filter paper, into a clean 100-mL bottle (see Note 6).Cap the bottle. Expose the collected water to the atmosphere aslittle as possible.8.5 Repeat 8.1 8.4, using the same syringe and filter ifadditional water is needed for experimentatio
32、n and can becollected. Usually about 25 mL of pore water may be collectedfrom 50 g of soil (see Note 7 and Note 8). Store the water at atemperature between 1 and 5C (see Note 9 and Sections 9 and10).8.6 Remove the soil from the press. If additional tests areanticipated, store soil in a sterile plast
33、ic bag at a temperaturebetween 1 and 5C (see Note 9).NOTE 4Only a few drops (0.05 mL) of pore fluid are required toconduct the soluble salt determination by refractometer. It is recom-mended that 25 mL of pore water be collected, if possible, to allow forretesting or additional tests, or both.NOTE 5
34、Kriukov and Komarova (4) have found that at a pressure of 59MPa the chloride content drops in homogeneous soils. Manheim (5)reports using 101 MPa routinely. An average of these two recommenda-tions is 80 MPa.NOTE 6Polyethylene or glass bottles should be washed with detergentand rinsed with tap water
35、. They should then be rinsed once with dilutedHCl (1:10) and twice with distilled water and then drained thoroughly.NOTE 7The amount of water expelled will depend on the initial watercontent of the sample. For example, using a 50-g sample of moist soil andassuming that 1 cm3of liquid is required to
36、fill the apparatus, thefollowing water contents are required to achieve the indicated amounts ofexpelled water:Initial Water Content Amount of Water Expelled (mL)104 2570 2047 1528 1014 520NOTE 8The addition of fluid to a sample to increase its water contentso that an increased amount of water can b
37、e expelled may result in theleaching of salts present in the soil and may distort the original salt contentof the pore water.NOTE 9Astorage temperature of about 5C is recommended to reducethe growth of sulfate-reducing bacterium called Desulfovibrio.9. Procedure9.1 Method ASalinity Determination Usi
38、ng a Refractome-ter with a Refraction Index Scale:9.1.1 Filter specimen through a 0.45-m filter.9.1.2 Thoroughly wash with distilled water and dry therefractometer, shown in Fig. 1. Zero the instrument in accor-dance with the manufacturers specifications.9.1.3 Place a few drops of liquid on the refr
39、actometerplatform and close the slide gently.9.1.4 Hold the refractometer at right angles to a light source,and read and record the refractive index.9.1.5 Obtain and record the salinity from the accompanyinggraph (Fig. 3), where n is the refractive index of the liquid andnothe refractive index of di
40、stilled water (1.330 at 20C).NOTE 10Atypical temperature-compensated instrument is accurate to0.1 % between 15.6 and 37.8C; the instrument is most accurate between18.3 and 21.1C.9.2 Method BSalinity Determination Using a Refractome-ter with a ppt Scale:9.2.1 Filter specimen through a 0.45-m filter.9
41、.2.2 Thoroughly wash with distilled water and dry therefractometer, shown in Fig. 1. Zero the instrument in accor-dance with the manufacturers specifications.9.2.3 Place one to two drops of liquid into the semicircle ofthe white plastic area, which is held firmly against the glassplatform. Allow the
42、 liquid to escape only under the whiteplastic area.9.2.4 Hold the refractometer at right angles to a light source,and read and record the salinity. If the liquid is properlyFIG. 2 Example of Heavy Duty Soil PressD4542 153introduced, there should be a distinct black/white boundary.Read and record whe
43、re the bottom of the hairline touches thebeginning of the black boundary. Read to the nearest wholenumber.NOTE 11Salinity is given in parts per thousand parts (0/00). Salinityis the total amount of solid material, in grams, contained in 1 kg of seawater when all the carbonate has been converted to o
44、xide, the bromine andiodine replaced by chlorine, and all organic matter completely oxidized(Sverdrup, Johnson, Fleming, (6).NOTE 12Error in reading directly from the salinity scale is 60.3 ppt.NOTE 13Actual sea water samples may have a black/yellow/whiteboundary when reading the refractometer. Read
45、ings are always taken atthe beginning of the black boundary. Two to three readings should alwaysbe taken to ensure accuracy and precision.10. Report: Test Data Sheet(s)/Forms(s)10.1 Record the date and testing personnel.10.2 The methodology used to specify how data are re-corded on the test data she
46、et(s)/form(s), as given below, iscovered in 1.8.10.3 For each test, record as a minimum the followingobservations:10.3.1 Location,10.3.2 Depth,10.3.3 Soil type,10.3.4 ppt or percent soluble solids,10.3.5 n, no, salinity, and10.3.6 Refraction index or parts per thousand (ppt) fromthree locations reco
47、rded to whole numbers.11. Precision and Bias11.1 PrecisionTest data on precision is not presented dueto the nature of the soil materials tested by this test method. Itis either not feasible or too costly at this time to have ten ormore laboratories participate in a round-robin testing program.In add
48、ition, it is either not feasible or too costly to producemultiple specimens that have uniform physical properties. Anyvariation observed in the data is just as likely to be due tospecimen variation as to operator or laboratory testing varia-tion.11.1.1 Subcommittee D18.06 is seeking any data from th
49、eusers of this test method that might be used to make a limitedstatement on precision.11.2 BiasThere is no accepted reference value for this testmethod, therefore bias cannot be determined.12. Keywords12.1 marine soils; porewater; refractometer; salt content;soluble salt; soluble salt contentAPPENDIX(Nonmandatory Information)X1. MASS COMPOSITIONX1.1 Mass Composition TermsX1.1.1 A mass composition diagram for partially saturatedsoils with soluble salts is shown in Fig. X1.1. Based on thisfigure the following terms and definitions are def
