ASTM D4318-17e1

Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils

SIGNIFICANCE AND USE
5.1 These test methods are used as an integral part of several engineering classification systems to characterize the fine-grained fractions of soils (see Practices D2487 and D3282) and to specify the fine-grained fraction of construction materials (see Specification D1241). The liquid limit, plastic limit, and plasticity index of soils are also used extensively, either individually or together, with other soil properties to correlate with engineering behavior such as compressibility, hydraulic conductivity (permeability), compactibility, shrink-swell, and shear strength. (See Section 6, Interferences.)  
5.2 The liquid and plastic limits of a soil and its water content can be used to express its relative consistency or liquidity index. In addition, the plasticity index and the percentage finer than 2-μm particle size can be used to determine its activity number.  
5.3 These methods are sometimes used to evaluate the weathering characteristics of clay-shale materials. When subjected to repeated wetting and drying cycles, the liquid limits of these materials tend to increase. The amount of increase is considered to be a measure of a shale's susceptibility to weathering.  
5.4 The liquid limit of a soil containing substantial amounts of organic matter decreases dramatically when the soil is oven-dried before testing. Comparison of the liquid limit of a sample before and after oven-drying can therefore be used as a qualitative measure of organic matter content of a soil (see Practice D2487).
Note 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740, generally, are considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors...
SCOPE
1.1 These test methods cover the determination of the liquid limit, plastic limit, and the plasticity index of soils as defined in Section 3 on Terminology.  
1.2 Two procedures for preparing test specimens are provided as follows: Specimen Preparation Procedure 1 (Wet Preparation), as described in 11.1 and Specimen Preparation Procedure 2 (Dry Preparation), as described in 11.2. The specimen preparation procedure to be used shall be specified by the requesting authority. If no specimen preparation procedure is specified, use the wet preparation procedure. (See Section 6, Interferences.)  
1.3 Two methods for determining the liquid limit are provided as follows: Liquid Limit Method A (Multipoint Method), as described in Sections 12 and 13, and Liquid Limit Method B (One-Point Method), as described in Sections 14 and 15. The method to be used shall be specified by the requesting authority. If no method is specified, use Method A. (See Section 6, Interferences.)  
1.4 The plastic limit test, Method for Plastic Limit, is performed on material prepared for the liquid limit test. When determining the plastic limit, two procedures for rolling portions of the test specimen are provided as follows: Plastic Limit Rolling Procedure 1 (Hand Rolling), and Plastic Limit Rolling Procedure 2 (Using the Rolling Device).  
1.5 The liquid limit and plastic limit of soils (along with the shrinkage limit) are often collectively referred to as the Atterberg limits. These limits distinguished the boundaries of the several consistency states of plastic soils.  
1.6 The plasticity index, Method for Plasticity Index, is calculated using results from liquid limit and plastic limit testing.  
1.7 The methods described herein are performed only on that portion of a soil that passes the 425-μm (No. 40) sieve. Therefore, the relative contribution of this portion of the soil to the properties of the sample as a whole must be considered when usin...

General Information

• Status: Published
• Publication Date: 31-May-2017
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.03 - Texture, Plasticity and Density Characteristics of Soils

Relations

• Replaces: ASTM D4318-17 - Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils
• Effective Date: 01-Jun-2017
• Refers: ASTM D4753-24 - Standard Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing
• Effective Date: 01-Feb-2024
• Refers: ASTM D3740-23 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Nov-2023
• Refers: ASTM D3740-19 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Oct-2019
• Refers: ASTM D420-18 - Standard Guide for Site Characterization for Engineering Design and Construction Purposes
• Effective Date: 01-Feb-2018
• Refers: ASTM D2487-17 - Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)
• Effective Date: 15-Dec-2017
• Refers: ASTM D3282-15 - Standard Practice for Classification of Soils and Soil-Aggregate Mixtures for Highway Construction Purposes
• Effective Date: 01-Nov-2015
• Refers: ASTM D1241-15 - Standard Specification for Materials for Soil-Aggregate Subbase, Base, and Surface Courses (Withdrawn 2024)
• Effective Date: 01-Nov-2015
• Refers: ASTM D4753-15 - Standard Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing
• Effective Date: 01-May-2015
• Refers: ASTM D653-14 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Aug-2014
• Refers: ASTM E177-14 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2014
• Refers: ASTM E11-13 - Standard Specification for Woven Wire Test Sieve Cloth and Test Sieves
• Effective Date: 01-Oct-2013
• Refers: ASTM E177-13 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM D3740-12a - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-May-2012

Overview

ASTM D4318-17e1: Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils provides foundational procedures widely used in geotechnical engineering to determine key soil consistency limits. Developed by ASTM, this international standard defines precise laboratory methods to quantify the liquid limit (LL), plastic limit (PL), and plasticity index (PI) for the fine-grained fraction of soils. These parameters, collectively known as the Atterberg limits, are critical for soil classification, construction material specification, and predicting soil behavior under various environmental and loading conditions.

The standard details specimen preparation (wet and dry), two techniques for liquid limit determination (multipoint and one-point methods), and procedures for measuring the plastic limit using hand rolling or a mechanical device. It also outlines interference factors, necessary apparatus, and guidance for sample collection and preparation.

Key Topics

• Soil Atterberg Limits: Establishes definitions and laboratory test methods for the liquid limit, plastic limit, and plasticity index of soils.
• Specimen Preparation: Describes wet and dry preparation methods tailored to different soil types and project requirements.
• Test Procedures:
  • Liquid Limit: Multipoint (Method A) and one-point (Method B) techniques, emphasizing accuracy, especially for soils with special characteristics (e.g., high organic matter).
  • Plastic Limit: Determined on material prepared for the liquid limit test, using hand rolling or a mechanical device.
  • Plasticity Index: Calculated as the difference between liquid limit and plastic limit.
• Sample Requirements: Tests are conducted on soil passing a 425-μm (No. 40) sieve, making the results most relevant for fine-grained soil fractions.
• Interferences: Notes impacts of drying, soluble salts, and organic content on test results and underscores the importance of appropriate technique selection.
• Significance in Engineering: Atterberg limits serve as critical input for soil classification systems (e.g., Unified Soil Classification System) and correlate with physical soil properties such as compressibility, shear strength, compactibility, and susceptibility to shrink-swell behavior or weathering.

Applications

Implementing ASTM D4318-17e1 offers practical value for the following applications:

• Soil Classification: The liquid limit, plastic limit, and plasticity index are routinely used in systems such as the Unified Soil Classification System (ASTM D2487) and highway construction soil classification (ASTM D3282).
• Material Specification: Supports defining the fine-grained fraction for construction materials, ensuring compliance with specifications like ASTM D1241.
• Geotechnical Design: Atterberg limits help predict engineering behavior, including compressibility, permeability, and shrink-swell potential, crucial for the safe and economic design of earthworks, embankments, and foundations.
• Assessment of Weathering and Organic Content: The variation of liquid limit after wetting/drying cycles and before/after oven-drying provides qualitative evaluation of a soil's weathering characteristics and organic matter content.
• Quality Control: Used to validate material properties and conformity during site investigation, construction, and earthwork projects.

Related Standards

For comprehensive soil testing and classification, ASTM D4318-17e1 should be used alongside these related standards:

• ASTM D2487 - Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)
• ASTM D3282 - Practice for Classification of Soils and Soil-Aggregate Mixtures for Highway Construction
• ASTM D1241 - Specification for Materials for Soil-Aggregate Subbase, Base, and Surface Courses
• ASTM D2216 - Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock
• ASTM C702 and ASTM D75 - Sampling and Reduction of Aggregate Samples
• ASTM D653 - Terminology Relating to Soil, Rock, and Contained Fluids

By following ASTM D4318-17e1, laboratories, engineers, and construction professionals can ensure reliable, repeatable, and standardized results for soil consistency limits, supporting improved design, performance forecasting, and material selection in civil engineering projects.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
´1
Designation: D4318 − 17
Standard Test Methods for
Liquid Limit, Plastic Limit, and Plasticity Index of Soils
This standard is issued under the fixed designation D4318; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript 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.
ε NOTE—Editorially updated units of measurement statement in April 2018.
1. Scope* 1.7 The methods described herein are performed only on
that portion of a soil that passes the 425-µm (No. 40) sieve.
1.1 These test methods cover the determination of the liquid
Therefore, the relative contribution of this portion of the soil to
limit, plastic limit, and the plasticity index of soils as defined
the properties of the sample as a whole must be considered
in Section 3 on Terminology.
when using these methods to evaluate the properties of a soil.
1.2 Two procedures for preparing test specimens are pro-
1.8 The values stated in SI units are to be regarded as
vided as follows: Specimen Preparation Procedure 1 (Wet
standard. The values given in parentheses after SI units are
Preparation), as described in 11.1 and Specimen Preparation
provided for information only and are not considered standard.
Procedure 2 (Dry Preparation), as described in 11.2. The
1.8.1 The converted inch-pound units use the gravitational
specimen preparation procedure to be used shall be specified
systemofunits.Inthissystem,thepound(lbf)representsaunit
by the requesting authority. If no specimen preparation proce-
of force (weight), while the unit for mass is slugs. The
dure is specified, use the wet preparation procedure. (See
converted slug unit is not given, unless dynamic (F = ma)
Section 6, Interferences.)
calculations are involved.
1.3 Two methods for determining the liquid limit are pro-
1.8.2 It is common practice in the engineering/construction
vided as follows: Liquid Limit Method A (Multipoint Method),
profession to concurrently use pounds to represent both a unit
as described in Sections 12 and 13, and Liquid Limit Method B
of mass (lbm) and of force (lbf). This implicitly combines two
(One-Point Method), as described in Sections 14 and 15. The
separate systems of units; that is, the absolute system and the
method to be used shall be specified by the requesting
gravitational system. It is scientifically undesirable to combine
authority. If no method is specified, use Method A. (See
the use of two separate sets of inch-pound units within a single
Section 6, Interferences.)
standard. As stated, this standard includes the gravitational
1.4 The plastic limit test, Method for Plastic Limit,is
system of inch-pound units and does not use/present the slug
performed on material prepared for the liquid limit test. When
unit for mass. However, the use of balances or scales recording
determining the plastic limit, two procedures for rolling por-
pounds of mass (lbm) or recording density in lbm/ft shall not
tionsofthetestspecimenareprovidedasfollows:PlasticLimit
be regarded as nonconformance with this standard.
Rolling Procedure 1 (Hand Rolling), and Plastic Limit Rolling
1.8.3 The “alternative” sieve size designations listed in
Procedure 2 (Using the Rolling Device).
Specification E11 for the 425-µm and 2.00-mm sieves are
given in parentheses following the “standard” designations,
1.5 The liquid limit and plastic limit of soils (along with the
that is, 425-µm (No. 40) and 2.00-mm (No. 10).
shrinkage limit) are often collectively referred to as the
1.8.4 The standard units for the resilience tester covered in
Atterberg limits. These limits distinguished the boundaries of
the several consistency states of plastic soils. Annex A1 are inch-pound, not SI. The SI values given in Fig.
A1.1 are for information only.
1.6 The plasticity index, Method for Plasticity Index,is
calculated using results from liquid limit and plastic limit
1.9 All observed and calculated values shall conform to the
testing. guidelines for significant digits and rounding established in
Practice D6026.
1.9.1 For purposes of comparing a measured or calculated
1 value(s) with specified limits, the measured or calculated
These test methods are under the jurisdiction ofASTM Committee D18 on Soil
and Rock and are the direct responsibility of Subcommittee D18.03 on Texture,
value(s) shall be rounded to the nearest decimal or significant
Plasticity and Density Characteristics of Soils.
digits in the specified limits.
CurrenteditionapprovedJune1,2017.PublishedJuly2017.Originallyapproved
ɛ1
1.9.2 Theproceduresusedtospecifyhowdataarecollected/
in 1983. Last previous edition approved in 2010 as D4318 – 10 . DOI: 10.1520/
D4318-17E01. recorded or calculated, in this standard are regarded as the
*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. United States
´1
D4318 − 17
industry standard. In addition, they are representative of the E691 Practice for Conducting an Interlaboratory Study to
significant digits that generally should be retained. The proce- Determine the Precision of a Test Method
dures do not consider material variation, purpose for obtaining
the data, special purpose studies, or any considerations for the 3. Terminology
user’s objectives; and it is common practice to increase or
3.1 Definitions:
reduce significant digits of reported data to be commensurate
3.1.1 Forcommondefinitionsoftermsinthisstandard,refer
with these considerations. It is beyond the scope of this
to Terminology D653. The definitions below appear in D653
standard to consider significant digits used in analysis methods
and are shown here for convenience. The italic capital letter
for engineering design.
“D” indicates that the applicable units used to express the term
1.10 This standard does not purport to address all of the
are dimensionless.
safety concerns, if any, associated with its use. It is the
3.1.2 Atterberg Limits—in cohesive soils, originally, six
responsibility of the user of this standard to establish appro-
“limits of consistency” of fine-grained soils were defined by
priate safety, health, and environmental practices and deter-
Albert Atterberg: the upper limit of viscous flow, the liquid
mine the applicability of regulatory limitations prior to use.
limit, the sticky limit, the cohesion limit, the plastic limit, and
1.11 This international standard was developed in accor-
the shrinkage limit. In current engineering usage, the term
dance with internationally recognized principles on standard-
usually refers only to the liquid limit, plastic limit, and in some
ization established in the Decision on Principles for the
references, the shrinkage limit.
Development of International Standards, Guides and Recom-
3.1.3 liquid limit, LL, w [D]—in cohesive soils, the water
L
mendations issued by the World Trade Organization Technical
content, in percent, of a soil at the arbitrarily defined boundary
Barriers to Trade (TBT) Committee.
between the semi-liquid and plastic states.
3.1.3.1 Discussion—The undrained shear strength of soil at
2. Referenced Documents
the liquid limit is considered to be approximately 2 kPa (0.28
2.1 ASTM Standards:
psi).
C702 PracticeforReducingSamplesofAggregatetoTesting
3.1.4 plastic limit, PL, w [D]—in cohesive soils, the water
p
Size
content,inpercent,ofasoilattheboundarybetweentheplastic
D75 Practice for Sampling Aggregates
and semi-solid states.
D420 Guide for Site Characterization for Engineering De-
3.1.5 plastic soil—a soil which has a range of water content
sign and Construction Purposes
over which it exhibits plasticity and which will retain its shape
D653 Terminology Relating to Soil, Rock, and Contained
on drying.
Fluids
D1241 Specification for Materials for Soil-Aggregate
3.1.6 plasticity index, PI—in cohesive soils, the range of
Subbase, Base, and Surface Courses
water content over which a soil behaves plastically.
D2216 Test Methods for Laboratory Determination of Water
Numerically, it is the difference between the liquid limit and
(Moisture) Content of Soil and Rock by Mass
the plastic limit.
D2487 Practice for Classification of Soils for Engineering
3.1.7 consistency—therelativeeasewithwhichasoilcanbe
Purposes (Unified Soil Classification System)
deformed.
D3282 Practice for Classification of Soils and Soil-
3.1.8 relative consistency, I,C [D]—in cohesive soils, the
Aggregate Mixtures for Highway Construction Purposes c r
ratio of: (1) the liquid limit minus the water content at a given
D3740 Practice for Minimum Requirements for Agencies
condition/state, to (2) the plasticity index.
Engaged in Testing and/or Inspection of Soil and Rock as
Used in Engineering Design and Construction
3.1.9 liquidity index, I [D]—in cohesive soils, the ratio of:
L
D4542 Test Methods for Pore Water Extraction and Deter-
(1) the water content of a soil at a given condition/state minus
mination of the Soluble Salt Content of Soils by Refrac-
its plastic limit, to (2) its plasticity index.
tometer
3.1.10 activity number, A—in cohesive soils, the ratio of (1)
D4753 Guide for Evaluating, Selecting, and Specifying Bal-
the plasticity index of a soil to (2) the percent by mass of
ances and Standard Masses for Use in Soil, Rock, and
particles having an equivalent diameter smaller than 2 µm.
Construction Materials Testing
D6026 Practice for Using Significant Digits in Geotechnical
4. Summary of Test Methods
Data
E11 Specification for Woven Wire Test Sieve Cloth and Test 4.1 The specimen is processed to remove any material
retained on a 425-µm (No. 40) sieve.
Sieves
E177 Practice for Use of the Terms Precision and Bias in
4.2 The liquid limit is determined by performing trials in
ASTM Test Methods
which a portion of the specimen is spread in a brass cup,
divided in two by a grooving tool, and then allowed to flow
together from the shocks caused by repeatedly dropping the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
cup in a standard mechanical device—following either Liquid
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Limit Method A (Multipoint Method),or Liquid Limit Method
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. B (One-Point Method).
´1
D4318 − 17
4.3 The plastic limit is determined by alternately pressing 6.2 The Liquid Limit Method A (Multipoint Method) is
together and rolling into a 3.2-mm ( ⁄8-in.) diameter thread a generally more precise than the one-point method. It is
small portion of plastic soil until its water content is reduced to recommended that the Liquid Limit Method A (Multipoint
a point at which the thread crumbles and can no longer be Method) be used in cases where test results may be subject to
pressed together and re-rolled. The water content of the soil at dispute, or where greater precision is required.
this point is reported as the plastic limit.
6.3 Because the Liquid Limit Method B (One-Point Method)
requires the operator to judge when the test specimen is
4.4 The plasticity index is calculated as the difference
approximately at its liquid limit, it is particularly not recom-
between the liquid limit and the plastic limit.
mended for use by inexperienced operators.
5. Significance and Use
6.4 The correlation on which the calculations of the Liquid
Limit Method B (One-Point Method) are based may not be
5.1 Thesetestmethodsareusedasanintegralpartofseveral
valid for certain soils, such as organic soils or soils from a
engineering classification systems to characterize the fine-
marineenvironment.Itisstronglyrecommendedthattheliquid
grained fractions of soils (see Practices D2487 and D3282) and
limit of these soils be determined by the Liquid Limit Method
to specify the fine-grained fraction of construction materials
A (Multipoint Method).
(see Specification D1241). The liquid limit, plastic limit, and
plasticity index of soils are also used extensively, either
6.5 The composition and concentration of soluble salts in a
individually or together, with other soil properties to correlate
soil affect the values of the liquid and plastic limits as well as
with engineering behavior such as compressibility, hydraulic
the water content values of soils (see Test Method D4542).
conductivity (permeability), compactibility, shrink-swell, and
Special consideration should therefore be given to soils from a
shear strength. (See Section 6, Interferences.)
marine environment or other sources where high soluble salt
concentrations may be present. The degree to which the salts
5.2 The liquid and plastic limits of a soil and its water
present in these soils are diluted or concentrated must be given
content can be used to express its relative consistency or
careful consideration.
liquidity index. In addition, the plasticity index and the
percentage finer than 2-µm particle size can be used to
7. Apparatus
determine its activity number.
7.1 Liquid Limit Device—Amechanicaldeviceconsistingof
5.3 These methods are sometimes used to evaluate the
a brass cup suspended from a carriage designed to control its
weathering characteristics of clay-shale materials. When sub-
drop onto the surface of a block of resilient material that serves
jected to repeated wetting and drying cycles, the liquid limits
as the base of the device. Fig. 1 shows the essential features
of these materials tend to increase. The amount of increase is
and dimensions of the device. The device may be operated by
considered to be a measure of a shale’s susceptibility to
either a hand crank or electric motor.
weathering.
NOTE 2—The dimensions marked as essential in Fig. 1 are necessary to
5.4 The liquid limit of a soil containing substantial amounts
properly manufacture the liquid limit device. Laboratories are not ex-
of organic matter decreases dramatically when the soil is
pected to have the capability to confirm all of the essential dimensions.
oven-dried before testing. Comparison of the liquid limit of a
Laboratories should have the ability to check critical dimensions subject
sample before and after oven-drying can therefore be used as a to wear as described in 10.1, Inspection of Wear.
qualitative measure of organic matter content of a soil (see
7.1.1 Base—Ablock of resilient material having a resilience
Practice D2487).
rebound of at least 77 % but no more than 90 %. Conduct
resilience tests on the finished base with the feet attached.
NOTE 1—The quality of the result produced by this standard is
Details for measuring the resilience of the base are given in
dependent on the competence of the personnel performing it and the
suitability of the equipment and facilities used. Agencies that meet the
Annex A1.
criteria of Practice D3740, generally, are considered capable of competent
7.1.2 Rubber Feet, supporting the base, designed to provide
and objective testing/sampling/inspection/etc. Users of this standard are
dynamic isolation of the base from the work surface.
cautioned that compliance with Practice D3740 does not in itself assure
7.1.3 Cup, brass, with a mass, including cup hanger, of 185
reliable results. Reliable results depend on many factors; Practice D3740
provides a means of evaluating some of those factors. to 215 g.
7.1.4 Cam—Designed to raise the cup smoothly and con-
6. Interferences
tinuously to its maximum height, over a distance of at least
180° of cam rotation, without developing an upward or
6.1 The liquid and plastic limits of many soils that have
downward velocity of the cup when the cam follower leaves
been allowed to dry before testing may be considerably
the cam. (The preferred cam motion is a uniformly accelerated
different from values obtained on non-dried samples. If the
lift curve.)
liquid and plastic limits of soils are used to correlate or
estimate the engineering behavior of soils in their natural moist NOTE 3—The cam and follower design in Fig. 1 is for uniformly
accelerated (parabolic) motion after contact and assures that the cup has
state, samples should not be permitted to dry before testing
no velocity at drop off. Other cam designs also provide this feature and
unless data on dried samples are specifically desired. For this
may be used. However, if the cam-follower lift pattern is not known, zero
reason Specimen Preparation Procedure 1 (Wet Preparation)is
velocity at drop off can be assured by carefully filing or machining the
used unless Specimen Preparation Procedure 2 (Dry Prepara-
cam and follower so that the cup height remains constant over the last 20
tion) is specified by the requesting authority. to 45° of cam rotation.
´1
D4318 − 17
FIG. 1 Hand-Operated Liquid Limit Device
7.1.5 Carriage, constructed in a way that allows convenient of-drop adjustments.The results obtained using a motor-driven
but secure adjustment of the height-of-drop of the cup to 10 device must not differ from those obtained using a manually
mm (0.394 in.), and designed such that the cup and cup hanger operated device.
assembly is only attached to the carriage by means of a
7.1.7 Counter (Optional)—A mechanism to automatically
removable pin. See 10.2 and Fig. 2 for explanation and
count the number of drops of the cup during operation of the
determination of the height-of-drop of the cup.
liquid limit device.
7.1.6 Motor Drive (Optional)—Asanalternativetothehand
7.2 Flat Grooving Tool—A tool made of plastic or
crank shown in Fig. 1, the device may be equipped with a
noncorroding-metal having the dimensions shown in Fig. 3.
motor to turn the cam. Such a motor must turn the cam at
The design of the tool may vary as long as the essential
2 6 0.1 revolutions per second and must be isolated from the
dimensions are maintained. The tool may, but need not,
rest of the device by rubber mounts or in some other way that
incorporate the height gauge (shown as dimension K) for
prevents vibration from the motor being transmitted to the rest
adjusting the height-of-drop of the liquid limit device.
of the apparatus. It must be equipped with an ON-OFF switch
and a means of conveniently positioning the cam for height- NOTE 4—Prior to the adoption of this test method, a curved grooving
FIG. 2 Adjustment for Height-of-Drop
´1
D4318 − 17
FIG. 3 Grooving Tool (Optional Height Gauge Attached)
tool was specified as part of the apparatus for performing the liquid limit
test. The curved tool is not considered to be as accurate as the flat tool
described in 7.2 since it does not control the depth of the soil in the liquid
limit cup. However, there are some data which indicate that typically the
liquid limit is slightly increased when the flat tool is used instead of the
curved tool.
NOTE 5—The dimensions marked as essential in Fig. 3 are necessary to
properly manufacture the grooving tool. Laboratories are not expected to
havethecapabilitytoconfirmalloftheessentialdimensions.Laboratories
should have the ability to check critical dimensions subject to wear as
described in 10.1.2.
7.3 Height Gauge—A metal gauge block for adjusting the
height-of-drop of the cup, having the dimensions shown in Fig.
FIG. 4 Height Gauge
4.The design of the tool may vary provided the gauge will rest
securely on the base without being susceptible to rocking, and
the edge which contacts the cup during adjustment is straight,
at least 10 mm ( ⁄8 in.) wide, and without bevel or radius.
7.6 Mixing and Storage Container or Dish—A container to
7.4 Water Content Containers—Small corrosion-resistant
mix the soil specimen (material) and store the prepared
containers with snug-fitting lids for water content specimens.
material. During mixing and storage, the container shall not
Aluminum or stainless steel cans 2.5 cm (1 in.) high by 5 cm
contaminate the material in any way, and prevent moisture loss
(2 in.) in diameter are appropriate.
duringstorage.Aporcelain,glass,orplasticdishabout11.4cm
7.5 Balance, conforming to Guide D4753, Class GP1 (read- (4 ⁄2 in.) in diameter and a plastic bag large enough to enclose
ability of 0.01 g). the dish and be folded over is adequate.
´1
D4318 − 17
7.7 Plastic Limit: 8. Reagents and Materials
7.7.1 Ground Glass Plate—A ground glass plate of suffi-
8.1 Purity of Water—Where distilled water is referred to in
cient size for rolling plastic limit threads.
this test method, either distilled or demineralized water may be
7.7.2 Plastic Limit-Rolling Device (optional)—A device
used.
made of acrylic conforming to the dimensions shown in Fig.
8.1.1 In some cases, the cations of salts present in tap water
3,4
5. The type of unglazed paper attached to the top and bottom
will exchange with the natural cations in the soil and signifi-
plate (see 17.2.2) shall be such that it does not add foreign
cantly alter the test results if tap water is used in the soaking
matter (fibers, paper fragments, etc.) to the soil during the
and washing operations. Unless it is known that such cations
rolling process.
are not present in the tap water, use distilled or demineralized
7.8 Spatula—A spatula or pill knife having a blade about 2 water.
cm ( ⁄4 in.) wide, and about 10 to 13 cm (4 to 5 in.) long.
NOTE 6—As a general rule, water containing more than 100 mg/L of
dissolved solids should not be used for either the soaking or washing
7.9 Sieve(s)—A 200-mm (8-in.) diameter, 425-µm (No. 40)
operations.
sieve conforming to the requirements of Specification E11 and
having a rim at least 5 cm (2 in.) above the mesh. A 2.00-mm
9. Sampling and Specimen
(No. 10) sieve meeting the same requirements may also be
needed. 9.1 Samples may be taken from any location that satisfies
testing needs. However, Practices C702 and D75 and Guide
7.10 Wash Bottle—Or similar container for adding con-
D420 should be used as guides for selecting and preserving
trolled amounts of water to soil and washing fines from coarse
samplesfromvarioustypesofsamplingoperations.Samplesin
particles.
which specimens will be prepared using the wet-preparation
7.11 Drying Oven—Meeting the requirements ofTest Meth-
procedure(11.1)mustbekeptattheiras-sampledwatercontent
ods D2216.
prior to preparation.
9.1.1 Where sampling operations have preserved the natural
7.12 Washing Pan—Round, flat-bottomed, at least 7.6 cm (3
stratification of a sample, the various strata must be kept
in.) deep, and slightly larger at the bottom than a 20.3-cm
separated and tests performed on the particular stratum of
(8-in.) diameter sieve.
interest with as little contamination as possible from other
strata. Where a mixture of materials will be used in
The plastic limit-rolling device is covered by a patent (U.S. Patent No.
construction, combine the various components in such propor-
5,027,660). Interested parties are invited to submit information regarding the
tions that the resultant sample represents the actual construc-
identification of an alternative(s) to this patented item toASTM Headquarters.Your
tion case.
comments will receive careful consideration at a meeting of the responsible
subcommittee, which you may attend.
9.1.2 Where data from these test methods are to be used for
Bobrowski,L.J.,Jr.andGriekspoor,D.M.,“DeterminationofthePlasticLimit
correlation with other laboratory or field test data, use the same
of a Soil by Means of a Rolling Device,” Geotechnical Testing Journal, GTJODJ,
material as used for those tests where possible.
Vol 15, No. 3, September 1992, pp. 284–287.
FIG. 5 Plastic Limit-Rolling Device
´1
D4318 − 17
base. For new cups, placing a piece of carbon paper on the base and
9.2 Specimen—Obtain a representative portion from the
allowing the cup to drop several times will mark the contact spot. Attach
total sample sufficient to provide 150 to 200 g of material
the cup to the device and turn the crank until the cup is raised to its
passing the 425-µm (No. 40) sieve. Free flowing samples
maximum height. Slide the height gauge under the cup from the front, and
(materials) may be reduced by the methods of quartering or
observe whether the gauge contacts the cup or the tape. (See Fig. 2.) If the
splitting. Non-free flowing or cohesive materials shall be
tape and cup are both simultaneously contacted, the height-of-drop is
ready to be checked. If not, adjust the cup until simultaneous contact is
mixed thoroughly in a pan with a spatula or scoop and a
made. Check adjustment by turning the crank at 2 revolutions per second
representative portion scooped from the total mass by making
while holding the gauge in position against the tape and cup. If a faint
one or more sweeps with a scoop through the mixed mass.
ringing or clicking sound is heard without the cup rising from the gauge,
the adjustment is correct. If no ringing is heard or if the cup rises from the
10. Verification of Apparatus
gauge, readjust the height-of-drop. If the cup rocks on the gauge during
this checking operation, the cam follower pivot is excessively worn and
10.1 Inspection of Wear:
the worn parts should be replaced. Always remove tape after completion
10.1.1 Liquid Limit Device—Determine that the liquid limit
of adjustment operation.
deviceiscleanandingoodworkingorder.Checkthefollowing
specific points.
11. Preparation Procedures for Test Specimens
10.1.1.1 Wear of Base—The spot on the base where the cup
11.1 Specimen Preparation Procedure 1 (Wet Preparation
makes contact should be worn no greater than 10 mm ( ⁄8 in.)
Procedure)—Except where Specimen Preparation Procedure 2
in diameter. If the wear spot is greater than this, the base can
(Dry Preparation Procedure) is specified (11.2), prepare the
be machined to remove the worn spot provided the resurfacing
specimen for testing as described in the following sections.
does not make the base thinner than specified in 7.1 and the
11.1.1 For Specimens Consisting of Material that Entirely
other dimensional relationships are maintained.
Passes the 425-µm (No. 40) Sieve:
10.1.1.2 Wear of Cup—Replace the cup when the grooving
11.1.1.1 Determine by visual and manual methods that the
tool has worn a depression in the cup 0.1 mm (0.004 in.) deep
specimen from 9.2 has little or no material retained on a
or when the rim of the cup has been reduced to half its original
425-µm (No. 40) sieve. If this is the case, prepare 150 to 200
thickness. Verify that the cup is firmly attached to the cup
g of material by mixing thoroughly with distilled or deminer-
hanger.
alized water on the glass plate or mixing dish using the spatula.
10.1.1.3 Wear of Cup Hanger—Verify that the cup hanger
If desired, soak the material in a mixing/storage dish with a
pivot does not bind and is not worn to an extent that allows
small amount of water to soften the material before the start of
more than 3 mm ( ⁄8 in.) side-to-side movement of the lowest
mixing(see8.1.1).IfusingLiquidLimitMethodA(Multipoint
point on the rim.
Method), adjust the water content of the material to bring it to
10.1.1.4 Wear of Cam—The cam shall not be worn to an
a consistency that would require about 25 to 35 drops of the
extent that the cup drops before the cup hanger (cam follower)
cup of the liquid limit device (commonly referred to as
loses contact with the cam.
“blows”) to close the groove. For Liquid Limit Method B
10.1.1.5 Rubber Feet—The feet should prevent the base
(One-Point Method), the number of drops should be between
from bouncing or sliding on the work surface. Replace rubber
about 20 and 30.
feet that become hard, cracked, or brittle from age.
11.1.1.2 If, during mixing, a small percentage of material is
10.1.2 Grooving Tools—Inspect grooving tools for wear on
encountered that would be retained on a 425-µm (No. 40)
a frequent and regular basis. The rapidity of wear depends on
sieve, remove these particles by hand (if possible). If it is
the material from which the tool is made, and the types of soils
impractical to remove the coarser material by hand, remove
being tested. Soils containing a large proportion of fine sand
smallpercentages(lessthanabout15 %)ofcoarsermaterialby
particles may cause rapid wear of grooving tools; therefore,
working the material (having the above consistency) through a
when testing these materials, tools should be inspected more
425-µm sieve. During this procedure, use a piece of rubber
frequently than for other soils.
sheeting, rubber stopper, or other convenient device provided
10.1.2.1 The critical grooving tool dimensions to be
theproceduredoesnotdistortthesieveordegradematerialthat
checked for wear are the width of the tip (dimension A in Fig.
would be retained if the washing method described in 11.1.2
3) and the depth of the tip (dimension D in Fig. 3).
were used. If larger percentages of coarse material are encoun-
NOTE7—Thewidthofthetipofgroovingtoolsisconvenientlychecked
tered during mixing, or it is considered impractical to remove
using a pocket-sized measuring magnifier equipped with a millimeter
the coarser material by the procedures just described, wash the
scale. Magnifiers of this type are available from most laboratory supply
sample as described in 11.1.2. When the coarse particles found
companies.Thedepthofthetipofgroovingtoolscanbecheckedusingthe
during mixing are concretions, shells, or other fragile particles,
depth-measuring feature of vernier calipers.
do not crush these particles to make them pass a 425-µm sieve,
10.2 Adjustment of Height-of-Drop—Adjust the height-of-
but remove by hand or by washing.
drop of the cup so that the point on the cup that comes in
11.1.1.3 Place the prepared material in the mixing/storage
contactwiththebaserisestoaheightof10 6 0.2mm.SeeFig.
dish,checkitsconsistency(adjustifrequired),covertoprevent
2 for proper location of the gauge relative to the cup during
loss of moisture, and allow to stand (cure) for at least 16 h
adjustment.
(overnight). After the standing period and immediately before
NOTE 8—Aconvenient procedure for adjusting the height-of-drop is as
starting the test, thoroughly remix the soil.
follows:placeapieceofmaskingtapeacrosstheoutsidebottomofthecup
parallel with the axis of the cup hanger pivot. The edge of the tape away NOTE 9—The time taken to adequately mix a soil will vary greatly,
from the cup hanger should bisect the spot on the cup that contacts the depending on the plasticity and initial water content. Initial mixing times
´1
D4318 − 17
of more than 30 min may be needed for stiff, fat clays.
on the glass plate. If using Liquid Limit MethodA(Multipoint
Method), the material should be at a water content that would
11.1.2 For Specimens Consisting of Material Containing
require about 25 to 35 drops of the cup of the liquid limit
Particles Retained on a 425-µm (No. 40) Sieve:
device to close the groove. For Liquid Limit Method B
11.1.2.1 Place the specimen (see 9.2) in a pan or dish and
(One-Point Method), the number of drops should be between
add sufficient water to cover the material.Allow the material to
about 20 and 30. Put, if necessary, the mixed material in the
soak until all lumps have softened and the fines no longer
storage dish, cover to prevent loss of moisture, and allow to
adhere to the surfaces of the coarse particles. (See 8.1.1.)
stand (cure) for at least 16 h. After the standing period and
11.1.2.2 When t
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