1、Designation: D 4542 07Standard Test Method forPore Water Extraction and Determination of the Soluble SaltContent of Soils by Refractometer1This standard is issued under the fixed designation D 4542; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se 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 a rapid procedure for squeezingpore water from fine-grained soil
3、s for the purpose of determin-ing the amount of soluble salts present in the extracted porewater.1.2 This test method was developed for soils having a watercontent 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 This test method is not generally applicable for deter-mining the soluble salt content of the pore water extracted fromcoarse-grained soils, such as clean sands and gravels.1.4 The values stated in SI units are to be regarded as thestandard. Th
5、e values given in parentheses are for informationonly.1.5 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 safety and health practices and determine the applica-bility
6、of regulatory limitations prior to use.1.6 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D 6026.2. Referenced Documents2.1 ASTM Standards:3D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 3740 Practice for M
7、inimum Requirements for AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionD 6026 Practice for Using Significant Digits in Geotechni-cal DataE 832 Specification for Laboratory Filter Papers2.2 Federal Document:GG-S-945a Specification for Sy
8、ringe and Needle, Dispos-able, Hypodermic, Sterile, Single Injection43. Terminology3.1 Definitions:3.1.1 For definitions of terms in this standard, refer toTerminology D 653.4. Significance and Use4.1 The soluble salt content may be used to correct the indexproperties of soils (water content, void r
9、atio, specific gravity,degree of saturation, and dry density).4.2 It is necessary to minimize the time period betweensampling and testing due to chemical changes which may occurwithin the soil sample.NOTE 1The quality of the result produced by this standard isdependent on the competence of the perso
10、nnel 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/etc. Users of this standard arecautioned that compliance with Practice D 3740 does not
11、 in itself assurereliable results. Reliable results depend on many factors; Practice D 3740provides a means of evaluating some of those factors.NOTE 2Hulbert and Brindle (2) and Torrance (3) have shown thatprolonged storage should be avoided as unpredictable and nonreproduc-ible chemical changes may
12、 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 PressThe apparatus shall conform to the require-ments shown in Fig. 2.1This test method is under
13、the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.06 on Physical-ChemicalInteractions of Soil and Rock.Current edition approved July 1, 2007. Published July 2007. Originally approvedin 1985. Last previous edition approved in 2001 as D 4542 95
14、(2001).2The boldface 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 D
15、ocument Summary page onthe ASTM website.4Available from Naval Publications and Forms Center, 5801 Tabor Ave.,Philadelphia, PA, 19120.1*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 19428-2959,
16、United States.5.3 SyringeA 25-cm3syringe without needle, in accor-dance with Fed. Std. GG-S-945a.5.4 BalanceA balance capable of weighing with a sensi-tivity of 60.01 g.5.5 Filter Paper:5.5.1 A general purpose quantitative filter paper in accor-dance with Specification E 832, Type II, Class F, for m
17、ediumcrystalline precipitates in the size range from 5 to 10 m, withan ash content of 0.13 mg/12.5-cm circle. Cut filter paper to adiameter of 55 mm (2.25 in.).5.5.2 A general purpose quantitative filter paper in accor-dance with Specification E 832, Type II, Class G, for finecrystalline precipitate
18、s 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 (0.98 in.).5.6 RefrigeratorCooling unit capable of maintaining auniform temperature between 1 and 5C.5.7 Micro-Syringe Filter HolderA device to filter a liquiddirectly from a syringe
19、.55.8 100-mL Polyethylene or Glass Bottle and Cap.5.9 Miscellaneous SuppliesDistilled water, alcohol, di-luted HCl (1:10), detergent, and optional sterile bags forsample storage (see 7.6).6. Preparation of Apparatus6.1 Wash all parts of the press thoroughly. Rinse twice withdistilled water and dry.
20、Normally, rust should not be present,but if it is to be removed, especially inside or around the top ofthe cylinder, scrub gently with steel wool and soap or chromicacid. Rinse well with tap water and then twice with distilledwater and dry.6.2 If the press parts have been coated with rust preventive
21、,wash them with alcohol and rinse once with tap water andtwice with distilled water.6.3 Dry 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.6.4 Assemble the press.5An apparatus such as the stainles
22、s steel Millipore Micro-Syringe Filter HolderXX30-025-00 is satisfactory for this purpose.FIG. 1 Typical Hand-Held RefractometerFIG. 2 Soil PressD 4542 072NOTE 3To prevent mud from circumventing the stainless steel wirescreen use flexible TFE-fluorocarbon gaskets on each side.7. Sampling and Test Sp
23、ecimen Squeezing7.1 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.7.2 Apply pressure slowly until the first drops of water areexpelled, then insert a clean, disposable, plastic syringe (25mL) in the effl
24、uent passage shown in Fig. 2. This is done tominimize the amount of air in the syringe and therefore, theamount of evaporation.7.3 Apply pressure gradually to a maximum of 80 MPa(11 520 psi), and hold until no more water is expelled or untilthe syringe is full (see Note 4 and Note 5).7.4 Withdraw th
25、e syringe when the pressure is at a maxi-mum and immediately expel the fluid from the syringe througha stainless 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
26、possible.7.5 Repeat 7.1-7.4, using the same syringe and filter ifadditional water is needed for experimentation and can becollected. Usually about 25 mL of pore water may be collectedfrom 50 g of sediment (see Note 7 and Note 8). Store the waterat a temperature between 1 and 5C (see Note 9 and Secti
27、ons8 and 9).7.6 Remove the soil from the press. If additional tests areanticipated, store soil in a sterile plastic 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-men
28、ded that 25 mL of pore water be collected, if possible, to allow forretesting or additional tests, or both.NOTE 5Kriukov and Komarova (4) have found that at a pressure of 59MPa (8500 psi) the chloride content drops in homogeneous soils.Manheim (5) reports using 101 MPa (14 700 psi) routinely.An aver
29、age ofthese two recommendations is 80 MPa (11 520 psi).NOTE 6Polyethylene or glass bottles should be washed with detergentand rinsed with tap water. 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 wi
30、ll 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 fill the apparatus, thefollowing water contents are required to achieve the indicated amounts ofexpelled water:Initial Water Content Amount of Water Expe
31、lled (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 be expelled may result in theleaching of salts present in the soil and may distort the original salt contentof the pore water.NOTE 9A storage temperature
32、of about 5C is recommended toreduce the growth of sulfate-reducing bacterium called Desulfovibrio.8. Procedure8.1 Method ASalinity Determination Using a Refractome-ter With a Refraction Index Scale:8.1.1 Filter specimen through a 0.45-m filter.8.1.2 Thoroughly wash with distilled water and dry there
33、fractometer, shown in Fig. 1.8.1.3 Place a few drops of liquid on the refractometerplatform and close the slide gently.8.1.4 Hold the refractometer at right angles to a light sourceand read the refractive index.8.1.5 Obtain salinity from the accompanying graph (Fig. 3),where n is the refractive inde
34、x of the liquid and notherefractive index of distilled 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.8.2 Method BSalinity Determination Using a Refractome-ter With a ppt Scale:
35、8.2.1 Thoroughly wash with distilled water and dry therefractometer, shown in Fig. 1.8.2.2 Place one to two drops of liquid into the semicircle ofthe white plastic area, which is held firmly against the glassplatform. Allow the liquid to escape only under the whiteplastic area.8.2.3 Hold the refract
36、ometer at right angles to a light sourceand read the salinity. If the liquid is properly introduced, thereshould be a distinct black/white boundary. Read where thebottom of the hairline touches the beginning of the blackboundary. Read to the nearest whole number.NOTE 11Salinity is given in parts per
37、 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 oxide, the bromine andiodine replaced by chlorine, and all organic matter completely oxidized(Sverdrup, Johnson, Fleming, (6).NOTE 12Error in re
38、ading directly from the salinity scale is 60.3 ppt.NOTE 13Actual sea water samples may have a black/yellow/whiteboundary when reading the refractometer. Readings are always taken atthe beginning of the black boundary. Two to three readings should alwaysbe taken to ensure accuracy and precision.FIG.
39、3 Graph of Salinity versus Refraction IndexD 4542 0739. Report: Test Data Sheet(s)/Forms(s)9.1 The methodology used to specify how data are recordedon the test data sheet(s)/form(s), as given below, is covered in1.6.9.2 For each test, a record of the following observations isrequired:9.2.1 Location,
40、9.2.2 Depth,9.2.3 Soil type,9.2.4 ppt or percent soluble solids,9.2.5 Water content, and9.2.6 Total density of undisturbed sample.10. Precision and Bias10.1 PrecisionTest data on precision is not presented dueto the nature of the soil materials tested by this test method. Itis either not feasible or
41、 too costly at this time to have ten ormore laboratories participate in a round-robin testing program.In addition, 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 vari
42、ation as to operator or laboratory testing varia-tion.10.1.1 Subcommittee D18.06 is seeking any data from theusers of this test method that might be used to make a limitedstatement on precision.10.2 BiasThere is no accepted reference value for this testmethod, therefore bias cannot be determined.11.
43、 Keywords11.1 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 this
44、figure the following terms and definitions are defined fordescribing various relationships among soil phases as proposedby Noorany (7). There are other phase relationship conventionsproposed in several references below which offer differentapproaches to calculating corrections (8-10) to the relatedi
45、ndex properties.M = wet massMd= oven dried mass (105C)Ms= mass of soil solids (excluding salt)Msa= mass of saltMsw= mass of sea waterr = salinity = Msa/Msw= mass of salt/mass of sea waterMw= mass of distilled water = MMdV = total volumeVs= volume of soil solids (excluding salt)Vsw= volume of sea sal
46、tVw= volume of distilled waterVg= volume of gasVv= volume of voids = Vsw+Vgrs= density of solids excluding saltro= density of distilled water at 4C = 1 g/cm3rsw= density of salt water at test temperature = 1.029g/cm3Gs= specific gravity of solids excluding salts = rs/ro.X1.2 Definitions and Phase Re
47、lations (7)X1.2.1 Using the terms defined in X1.1.1 and referring toFig. X1.1, Mw=MMd=MswMsa=Msw(1r) whichyields the following:Msw5M 2 Md1 2 r(X1.1)FIG. X1.1 Mass Composition Diagram for Soils ContainingSoluble SaltsD 4542 074Ms5 M 2 Msw5Md2 rM1 2 r(X1.2)Vsw5Mswrsw5M 2 Md1 2 r!rsw(X1.3)Vs5MsGsro5MsG
48、sro5Md2 rM1 2 r!Gsro(X1.4)X1.2.2 The following terms are defined as follows:Density r5MV(X1.5)Dry density rd5MsV5Md2 rMV1 2 r!2 (X1.6)Water content %! w 5MwMd3 100 5M 2 MdMd3 100 (X1.7)Fluid content %! w 5MswMs3 100 5M 2 MdMd2 rM3 100 (X1.8)Void ratio e 5VvVs5V1 2 r!GsroMd2 rM2 1 (X1.9)Porosity n 5V
49、vV3 100 % (X1.10)n 5F1 2Md2 rM!v1 2 r!GsroG3 100 (X1.11)Degree of saturations 5VswVv3 100 (X1.12)s 5GsM 2 Md!v1 2 r!Gsro2 Md1 rMrorsw3 100 (X1.13)X1.3 Other Useful RelationshipsMd5M1 1 w(X1.14)Ms5M1 1 w(X1.15)rd5r1 1 w(X1.16)n 5e1 1 e(X1.17)w 5w1 2 r 2 rw(X1.18)e 5VGsro1 1 w !M21 (X1.19)ore 5wGsS3rorsw(X1.20)REFERENCES(1) Kriukov, P. A., and Manheim, F. T.,“ Extraction and InvestigativeTechniques for Study of Interstitial Waters of Unconsolidated Sedi-ments: A Review,” Dynamic Environment of the Sea Floor, Lexi
