1、Designation: D4318 101Standard Test Methods forLiquid Limit, Plastic Limit, and Plasticity Index of Soils1This standard is issued under the fixed designation D4318; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1NOTEEditorial corrections made throughout in Janu
3、ary 2014.1. Scope*1.1 These test methods cover the determination of the liquidlimit, plastic limit, and the plasticity index of soils as definedin Section 3 on Terminology.1.2 Two methods for preparing test specimens are providedas follows: Wet preparation method, as described in 10.1. Drypreparatio
4、n method, as described in 10.2. The method to beused shall be specified by the requesting authority. If nomethod is specified, use the wet preparation method.1.2.1 The liquid and plastic limits of many soils that havebeen allowed to dry before testing may be considerablydifferent from values obtaine
5、d on non-dried samples. If theliquid and plastic limits of soils are used to correlate orestimate the engineering behavior of soils in their natural moiststate, samples should not be permitted to dry before testingunless data on dried samples are specifically desired.1.3 Two methods for determining
6、the liquid limit are pro-vided as follows: Method A, Multipoint test as described inSections 11 and 12. Method B, One-point test as described inSections 13 and 14. The method to be used shall be specifiedby the requesting authority. If no method is specified, useMethod A.1.3.1 The multipoint liquid
7、limit method is generally moreprecise than the one-point method. It is recommended that themultipoint method be used in cases where test results may besubject to dispute, or where greater precision is required.1.3.2 Because the one-point method requires the operator tojudge when the test specimen is
8、 approximately at its liquidlimit, it is particularly not recommended for use by inexperi-enced operators.1.3.3 The correlation on which the calculations of theone-point method are based may not be valid for certain soils,such as organic soils or soils from a marine environment. It isstrongly recomm
9、ended that the liquid limit of these soils bedetermined by the multipoint method.1.4 The plastic limit test is performed on material preparedfor the liquid limit test.1.5 The liquid limit and plastic limit of soils (along with theshrinkage limit) are often collectively referred to as theAtterberg li
10、mits. These limits distinguished the boundaries ofthe several consistency states of plastic soils.1.6 The composition and concentration of soluble salts in asoil affect the values of the liquid and plastic limits as well asthe water content values of soils (see Test Method D4542).Special considerati
11、on should therefore be given to soils from amarine environment or other sources where high soluble saltconcentrations may be present. The degree to which the saltspresent in these soils are diluted or concentrated must be givencareful consideration.1.7 The methods described herein are performed only
12、 onthat portion of a soil that passes the 425-m (No. 40) sieve.Therefore, the relative contribution of this portion of the soil tothe properties of the sample as a whole must be consideredwhen using these tests to evaluate properties of a soil.1.8 The values stated in SI units are to be regarded as
13、thestandard, except as noted below. The values given in parenthe-ses are for information only.1.8.1 The standard units for the resilience tester covered inAnnex A1 are inch-pound, not SI. The SI values given are forinformation only.1.9 All observed and calculated values shall conform to theguideline
14、s for significant digits and rounding established inPractice D6026.1.9.1 For purposes of comparing a measured or calculatedvalue(s) with specified limits, the measured or calculatedvalue(s) shall be rounded to the nearest decimal or significantdigits in the specified limits1.9.2 The procedures used
15、to specify how data are collected/recorded or calculated, in this standard are regarded as theindustry standard. In addition, they are representative of thesignificant digits that generally should be retained. The proce-dures do not consider material variation, purpose for obtaining1These test metho
16、ds are under the jurisdiction ofASTM Committee D18 on Soiland Rock and are the direct responsibility of Subcommittee D18.03 on Texture,Plasticity and Density Characteristics of Soils.Current edition approved Jan. 15, 2010. Published March 2010. Originallyapproved in 1983. Last previous edition appro
17、ved in 2005 as D4318 05. DOI:10.1520/D4318-10E01.*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 States1the data, special purpose studies, or any considerations for theusers ob
18、jectives; and it is common practice to increase orreduce significant digits of reported data to be commensuratewith these considerations. It is beyond the scope of thisstandard to consider significant digits used in analysis methodsfor engineering design.1.10 This standard does not purport to addres
19、s 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 of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C702 Practice fo
20、r 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 ContainedFluidsD1241 Specification for Materials for Soil-AggregateSubbas
21、e, Base, and Surface CoursesD2216 Test Methods for Laboratory Determination of Water(Moisture) Content of Soil and Rock by MassD2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D3282 Practice for Classification of Soils and Soil-Aggregate Mixtures
22、 for Highway Construction PurposesD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4542 Test Method for Pore Water Extraction and Determi-nation of the Soluble Salt Content of Soils by Refracto-met
23、erD4753 Guide for Evaluating, Selecting, and Specifying Bal-ances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD6026 Practice for Using Significant Digits in GeotechnicalDataE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE177 Practice for Use of the Te
24、rms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 For common definitions of terms in this standard, referto Terminology D653.3.1.2 Atterberg LimitsOriginally, six “limits of co
25、nsis-tency” of fine-grained soils were defined by Albert Atterberg:the upper limit of viscous flow, the liquid limit, the sticky limit,the cohesion limit, the plastic limit, and the shrinkage limit. Incurrent engineering usage, the term usually refers only to theliquid limit, plastic limit, and in s
26、ome references, the shrinkagelimit.3.1.3 consistencythe relative ease with which a soil can bedeformed.3.1.4 liquid limit (LL, wL)the water content, in percent, ofa soil at the arbitrarily defined boundary between the semi-liquid and plastic states.3.1.4.1 DiscussionThe undrained shear strength of s
27、oil atthe liquid limit is considered to be approximately 2 kPa (0.28psi).3.1.5 plastic limit (PL, wp)the water content, in percent, ofa soil at the boundary between the plastic and semi-solid states.3.1.6 plastic soila soil which has a range of water contentover which it exhibits plasticity and whic
28、h will retain its shapeon drying.3.1.7 plasticity index (PI)the range of water content overwhich a soil behaves plastically. Numerically, it is the differ-ence between the liquid limit and the plastic limit.3.1.8 liquidity indexthe ratio, expressed as a percentage of(1) the water content of a soil m
29、inus its plastic limit, to (2) itsplasticity index.3.1.9 activity number (A)the ratio of (1) the plasticityindex of a soil to (2) the percent by mass of particles having anequivalent diameter smaller than 2 m.4. Summary of Test Method4.1 The specimen is processed to remove any materialretained on a
30、425-m (No. 40) sieve. The liquid limit isdetermined by performing trials in which a portion of thespecimen is spread in a brass cup, divided in two by a groovingtool, and then allowed to flow together from the shocks causedby repeatedly dropping the cup in a standard mechanicaldevice. The multipoint
31、 liquid limit, MethodA, requires three ormore trials over a range of water contents to be performed andthe data from the trials plotted or calculated to make arelationship from which the liquid limit is determined. Theone-point liquid limit, Method B, uses the data from two trialsat one water conten
32、t multiplied by a correction factor todetermine the liquid limit.4.2 The plastic limit is determined by alternately pressingtogether and rolling into a 3.2-mm (18-in.) diameter thread asmall portion of plastic soil until its water content is reduced toa point at which the thread crumbles and can no
33、longer bepressed together and re-rolled. The water content of the soil atthis point is reported as the plastic limit.4.3 The plasticity index is calculated as the differencebetween the liquid limit and the plastic limit.5. Significance and Use5.1 These test methods are used as an integral part of se
34、veralengineering classification systems to characterize the fine-grained fractions of soils (see Practices D2487 and D3282) and2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information
35、, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.D4318 1012to specify the fine-grained fraction of construction materials(see Specification D1241). The liquid limit, plastic limit, andplasticity inde
36、x of soils are also used extensively, eitherindividually or together, with other soil properties to correlatewith engineering behavior such as compressibility, hydraulicconductivity (permeability), compactibility, shrink-swell, andshear strength.5.2 The liquid and plastic limits of a soil and its wa
37、tercontent can be used to express its relative consistency orliquidity index. In addition, the plasticity index and thepercentage finer than 2-m particle size can be used todetermine its activity number.5.3 These methods are sometimes used to evaluate theweathering characteristics of clay-shale mate
38、rials. When sub-jected to repeated wetting and drying cycles, the liquid limitsof these materials tend to increase. The amount of increase isconsidered to be a measure of a shales susceptibility toweathering.5.4 The liquid limit of a soil containing substantial amountsof organic matter decreases dra
39、matically when the soil isoven-dried before testing. Comparison of the liquid limit of asample before and after oven-drying can therefore be used as aqualitative measure of organic matter content of a soil (seePractice D2487.NOTE 1The quality of the result produced by this standard isdependent on th
40、e competence of the personnel performing it and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740, generally, are considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with
41、 Practice D3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors.6. Apparatus6.1 Liquid Limit DeviceAmechanical device consisting ofa brass cup suspended from a carriage designed to control itsdrop
42、onto the surface of a block of resilient material that servesas the base of the device. Fig. 1 shows the essential featuresand critical dimensions of the device. The device may beoperated by either a hand crank or electric motor.6.1.1 BaseAblock of material having a resilience reboundof at least 77
43、% but no more than 90 %. Conduct resiliencetests on the finished base with the feet attached. Details formeasuring the resilience of the base are given in Annex A1.6.1.2 Rubber Feet, supporting the base, designed to providedynamic isolation of the base from the work surface.6.1.3 Cup, brass, with a
44、mass, including cup hanger, of 185to 215 g.6.1.4 CamDesigned to raise the cup smoothly and con-tinuously to its maximum height, over a distance of at least180 of cam rotation, without developing an upward ordownward velocity of the cup when the cam follower leavesthe cam. (The preferred cam motion i
45、s a uniformly acceleratedlift curve.)NOTE 2The cam and follower design in Fig. 1 is for uniformlyaccelerated (parabolic) motion after contact and assures that the cup hasno velocity at drop off. Other cam designs also provide this feature andmay be used. However, if the cam-follower lift pattern is
46、not known, zerovelocity at drop off can be assured by carefully filing or machining thecam and follower so that the cup height remains constant over the last 20to 45 of cam rotation.6.1.5 Carriage, constructed in a way that allows convenientbut secure adjustment of the height-of-drop of the cup to 1
47、0FIG. 1 Hand-Operated Liquid Limit DeviceD4318 1013mm (0.394 in.), and designed such that the cup and cup hangerassembly is only attached to the carriage by means of aremovable pin. See Fig. 2 for definition and determination ofthe height-of-drop of the cup.6.1.6 Motor Drive (Optional)As an alternat
48、ive to the handcrank shown in Fig. 1, the device may be equipped with amotor to turn the cam. Such a motor must turn the cam at2 6 0.1 revolutions per second and must be isolated from therest of the device by rubber mounts or in some other way thatprevents vibration from the motor being transmitted
49、to the restof the apparatus. It must be equipped with an ON-OFF switchand a means of conveniently positioning the cam for height-of-drop adjustments. The results obtained using a motor-drivendevice must not differ from those obtained using a manuallyoperated device.6.2 Flat Grooving ToolA tool made of plastic ornoncorroding-metal having the dimensions shown in Fig. 3.The design of the tool may vary as long as the essentialdimensions are maintained. The tool may, but need not,incorporate the gauge for adjusting the height-of-drop of theliquid limit dev
