ASTM D4221-18
(Test Method)Standard Test Method for Dispersive Characteristics of Clay Soil by Double Hydrometer
Standard Test Method for Dispersive Characteristics of Clay Soil by Double Hydrometer
SIGNIFICANCE AND USE
5.1 Dispersive clays are those which normally deflocculate when exposed to water of low-salt concentration, the opposite of aggregated clays that would remain flocculated in the same soil-water system (3, 4, 7). Generally, dispersive clays are highly erosive, possibly subject to high shrink-swell potential, may have lower shear strength, and have lower permeability rates than aggregated clays.
5.2 When the percent dispersion equals 100, it indicates a completely dispersive clay-size fraction. When the percent dispersion equals 0, it indicates completely nondispersive clay-size fraction.
5.3 Available data (1) indicates that the test method has about 85 % reliance in predicting dispersive performance (85 % of dispersive clays show more than 35 % dispersion).
5.4 Since this test method may not identify all dispersive clays, design decisions based solely on this test method may not be conservative. It is often run in conjunction with the crumb test (D6572) (4, 7), the pinhole test (D4647/D4647M), or the analysis of the pore water extract (D4542) (4, 7), or combination thereof, to identify possible dispersive clay behavior.
Note 1: The quality of the result produced by this standard is dependent on the competence of the personal performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally 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 depends on many factors; Practice D3740 provides a means of evaluating some of those factors.
SCOPE
1.1 This test method provides an indication of the natural dispersive characteristics of clay soils by comparing the amount of particles finer than 2-μm as determined by this method compared to the amount of particles finer than 2-μm as determined by Test Method D7928 (1).2 In order to do this comparison, two similar specimens must be obtained from the sample.
1.2 This test method follows the procedure given in Test Method D7928 with the exception that the soil slurry is not mechanically dispersed and no dispersing agent is added.
1.3 This test method is applicable only to soils where the position of the plasticity index versus liquid limit plots (Test Methods D4318) falls on or above the “A” line (Practice D2487) and more than 12 % of the soil fraction is finer than 2-μm as determined in accordance with Test Method D7928 (2).
1.4 Since this test method may not identify all dispersive clay soils, other tests such as, pinhole dispersion (Test Methods D4647/D4647M), crumb (Test Methods D6572) (3-5) and the analysis of pore water extraction (Test Methods D4542) (4-7) may be performed individually or used together to help verify dispersion.
1.5 Units—The values stated in SI units are to be regarded as the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method.
1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.
1.6.1 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user's objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use...
General Information
Relations
Buy Standard
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.
Designation: D4221 − 18
Standard Test Method for
Dispersive Characteristics of Clay Soil by Double
1
Hydrometer
This standard is issued under the fixed designation D4221; 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.
1. Scope* obtaining the data, special purpose studies, or any consider-
ations for the user’s objectives; and it is common practice to
1.1 This test method provides an indication of the natural
increase or reduce significant digits of reported data to be
dispersive characteristics of clay soils by comparing the
commensuratewiththeseconsiderations.Itisbeyondthescope
amount of particles finer than 2-µm as determined by this
of this standard to consider significant digits used in analysis
method compared to the amount of particles finer than 2-µm as
2 methods for engineering design.
determined by Test Method D7928(1). In order to do this
1.7 This standard does not purport to address all of the
comparison, two similar specimens must be obtained from the
safety concerns, if any, associated with its use. It is the
sample.
responsibility of the user of this standard to establish appro-
1.2 This test method follows the procedure given in Test
priate safety, health, and environmental practices and deter-
Method D7928 with the exception that the soil slurry is not
mine the applicability of regulatory limitations prior to use.
mechanically dispersed and no dispersing agent is added.
1.8 This international standard was developed in accor-
1.3 This test method is applicable only to soils where the
dance with internationally recognized principles on standard-
position of the plasticity index versus liquid limit plots (Test
ization established in the Decision on Principles for the
Methods D4318) falls on or above the “A” line (Practice
Development of International Standards, Guides and Recom-
D2487) and more than 12 % of the soil fraction is finer than
mendations issued by the World Trade Organization Technical
2-µmasdeterminedinaccordancewithTestMethodD7928(2).
Barriers to Trade (TBT) Committee.
1.4 Since this test method may not identify all dispersive
2. Referenced Documents
claysoils,othertestssuchas,pinholedispersion(TestMethods
3
2.1 ASTM Standards:
D4647/D4647M), crumb (Test Methods D6572)(3-5) and the
D653 Terminology Relating to Soil, Rock, and Contained
analysis of pore water extraction (Test Methods D4542)(4-7)
Fluids
may be performed individually or used together to help verify
D2216 Test Methods for Laboratory Determination of Water
dispersion.
(Moisture) Content of Soil and Rock by Mass
1.5 Units—The values stated in SI units are to be regarded
D2487 Practice for Classification of Soils for Engineering
as the standard. Reporting of test results in units other than SI
Purposes (Unified Soil Classification System)
shall not be regarded as nonconformance with this test method.
D2488 Practice for Description and Identification of Soils
1.6 All observed and calculated values shall conform to the
(Visual-Manual Procedures)
guidelines for significant digits and rounding established in
D3740 Practice for Minimum Requirements for Agencies
Practice D6026.
Engaged in Testing and/or Inspection of Soil and Rock as
1.6.1 Theproceduresusedtospecifyhowdataarecollected/
Used in Engineering Design and Construction
recorded or calculated, in this standard are regarded as the
D4220/D4220M Practices for Preserving and Transporting
industry standard. In addition, they are representative of the
Soil Samples
significant digits that generally should be retained. The proce-
D4318 Test Methods for Liquid Limit, Plastic Limit, and
dures used do not consider material variation, purpose for
Plasticity Index of Soils
D4542 Test Methods for Pore Water Extraction and Deter-
1 mination of the Soluble Salt Content of Soils by Refrac-
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
RockandisthedirectresponsibilityofSubcommitteeD18.06onPhysical-Chemical
tometer
Interactions of Soil and Rock.
Current edition approved Jan. 1, 2018. Published February 2018. Originally
3
approved in 1983. Last previous edition approved in 2017 as D4221–17. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/D4221-18. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
2
The boldface numbers in parentheses refer to the list of references appended to Standards volume information, refer to the standard’s Document Summary page on
t
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D4221 − 17 D4221 − 18
Standard Test Method for
Dispersive Characteristics of Clay Soil by Double
1
Hydrometer
This standard is issued under the fixed designation D4221; 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.
1. Scope*
1.1 This test method provides an indication of the natural dispersive characteristics of clay soils by comparing the amount of
particles finer than 2-μm as determined by this method compared to the amount of particles finer than 2-μm as determined by Test
2
Method D7928(1). In order to do this comparison, two similar specimens must be obtained from the sample.
1.2 This test method follows the procedure given in Test Method D7928 with the exception that the soil slurry is not
mechanically dispersed and no dispersing agent is added.
1.3 This test method is applicable only to soils where the position of the plasticity index versus liquid limit plots (Test Methods
D4318) falls on or above the “A” line (Practice D2487) and more than 12 % of the soil fraction is finer than 2-μm as determined
in accordance with Test Method D7928(2).
1.4 Since this test method may not identify all dispersive clay soils, other tests such as, pinhole dispersion (Test Methods
D4647/D4647M), crumb (Test Methods D6572) (3-5) and the analysis of pore water extraction (Test Methods D4542) (4-7) may
be performed individually or used together to help verify dispersion.
1.5 Units—The values stated in SI units are to be regarded as the standard. Reporting of test results in units other than SI shall
not be regarded as nonconformance with this test method.
1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice
D6026.
1.6.1 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industry
standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not
consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives;
and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations.
It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.8 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.
2. Referenced Documents
3
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
D2487 Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)
D2488 Practice for Description and Identification of Soils (Visual-Manual Procedures)
1
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.06 on Physical-Chemical
Interactions of Soil and Rock.
Current edition approved July 1, 2017Jan. 1, 2018. Published July 2017February 2018. Originally approved in 1983. Last previous edition approved in 20112017 as
D4221–11.–17. DOI: 10.1520/D4221-17.10.1520/D4221-18.
2
The boldface numbers in parentheses refer to the list of references appended to this standard.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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. Uni
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.