ASTM D1883-21
(Test Method)Standard Test Method for California Bearing Ratio (CBR) of Laboratory-Compacted Soils
Standard Test Method for California Bearing Ratio (CBR) of Laboratory-Compacted Soils
SIGNIFICANCE AND USE
5.1 This test method can be used in a number of engineering applications such as to evaluate the potential strength of subgrade, subbase, and base course materials, including recycled materials for use in the design of flexible roads and airfield pavements.
Note 1: As with other laboratory test methods, the user should consider whether results from this test are appropriate for the intended design use. Considerations may include roadbed conditions, environmental conditions, soil saturation, drainage effects, seasonal effects, etc.
5.2 For applications where the effect of compaction water content on CBR is small, such as cohesionless, coarse-grained materials, or where an allowance is made for the effect of differing compaction water contents in the design procedure, the CBR may be determined at the optimum water content of a specified compaction effort. The specified dry unit weight is normally the minimum percent compaction allowed by the using client’s field compaction specification.
5.3 For applications where the effect of compaction water content on CBR is unknown or where it is desired to account for its effect, the CBR is determined for a range of water contents, usually the range of water content permitted for field compaction by using the client’s protocol or specification for field compaction.
5.4 The criteria for test specimen preparation of self-cementing (and other) materials which gain strength with time must be based on a geotechnical engineering evaluation. As directed by the client, self-cementing materials shall be properly cured until bearing ratios representing long term service conditions can be measured.
Note 2: The quality of the results 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 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of ...
SCOPE
1.1 This test method covers the determination of the California Bearing Ratio (CBR) of laboratory compacted specimens. The test method is primarily intended for, but not limited to, evaluating the strength of materials having maximum particle size less than 3/4 in. (19 mm).
1.2 When materials having a maximum particle size greater than 3/4 in. (19 mm) are to be tested, this test method provides for modifying the gradation of the material so that the material used for testing all passes the 3/4-in. (19-mm) sieve while the total gravel fraction (material passing the 3-in. (75-mm) sieve and retained on the No. 4 (4.75-mm) sieve) remains the same. While traditionally this method of specimen preparation has been used to avoid the error inherent in testing materials containing large particles in the CBR test apparatus, the modified material may have significantly different strength properties than the original material. However, a large experience database has been developed using this test method for materials for which the gradation has been modified, and satisfactory design methods are in use based on the results of tests using this procedure.
1.3 Past practice has shown that CBR results for those materials having substantial percentages of particles retained on the No. 4 (4.75 mm) sieve are more variable than for finer materials. Consequently, more trials may be required for these materials to establish a reliable CBR.
1.4 This test method provides for the determination of the CBR of a material at optimum water content or a range of water contents from a specified compaction test and a specified dry unit weight. The dry unit weight is usually given as a percentage of maximum dry unit weight determined by Test Methods D698 or D1557.
1.4.1 The client requesting the CBR test may specify the water content or range of water contents and/or the dry unit weight for which the CBR is desired.
1.5 Unless specified oth...
General Information
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: D1883 − 21
Standard Test Method for
California Bearing Ratio (CBR) of Laboratory-Compacted
1
Soils
This standard is issued under the fixed designation D1883; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber 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.
1. Scope* 1.4.1 The client requesting the CBR test may specify the
water content or range of water contents and/or the dry unit
1.1 This test method covers the determination of the Cali-
weight for which the CBR is desired.
fornia Bearing Ratio (CBR) of laboratory compacted speci-
1.5 Unless specified otherwise by the requesting client, or
mens.Thetestmethodisprimarilyintendedfor,butnotlimited
to, evaluating the strength of materials having maximum unlessithasbeenshowntohavenoeffectontestresultsforthe
3
material being tested, all specimens shall be soaked prior to
particle size less than ⁄4 in. (19 mm).
penetration.
1.2 When materials having a maximum particle size greater
3
1.6 Units—The values stated in inch-pound units are to be
than ⁄4 in. (19 mm) are to be tested, this test method provides
regarded as standard. The SI units given in parentheses are
for modifying the gradation of the material so that the material
3
mathematical conversions, which are provided for information
used for testing all passes the ⁄4-in. (19-mm) sieve while the
purposes only and are not considered standard. Reporting of
total gravel fraction (material passing the 3-in. (75-mm) sieve
test results in units other than inch-pound units shall not be
and retained on the No. 4 (4.75-mm) sieve) remains the same.
regarded as nonconformance with this test method.
While traditionally this method of specimen preparation has
been used to avoid the error inherent in testing materials 1.6.1 The gravitational system of inch-pound units is used
containing large particles in the CBR test apparatus, the when dealing with inch-pound units. In this system, the pound
(lbf)representsaunitofforce(weight),whiletheunitformass
modified material may have significantly different strength
properties than the original material. However, a large experi- is slugs. The slug unit is not given, unless dynamic (F = ma)
calculations are involved.
ence database has been developed using this test method for
materials for which the gradation has been modified, and
1.6.2 The slug unit of mass is almost never used in
satisfactory design methods are in use based on the results of
commercial practice; that is, density, balances, etc. Therefore,
tests using this procedure.
the standard unit for mass in this standard is either kilogram
(kg) or gram (g), or both.Also, the equivalent inch-pound unit
1.3 Past practice has shown that CBR results for those
(slug) is not given/presented in parentheses.
materials having substantial percentages of particles retained
1.6.3 It is common practice in the engineering/construction
on the No. 4 (4.75 mm) sieve are more variable than for finer
profession, in the United States, to concurrently use pounds to
materials. Consequently, more trials may be required for these
represent both a unit of mass (lbm) and of force (lbf). This
materials to establish a reliable CBR.
implicitly combines two separate systems of units; that is, the
1.4 This test method provides for the determination of the
absolutesystemandthegravitationalsystem.Itisscientifically
CBR of a material at optimum water content or a range of
undesirable to combine the use of two separate sets of
watercontentsfromaspecifiedcompactiontestandaspecified
inch-pound units within a single standard. As stated, this
dry unit weight. The dry unit weight is usually given as a
standard includes the gravitational system of inch-pound units
percentage of maximum dry unit weight determined by Test
and does not use/present the slug unit for mass. However, the
Methods D698 or D1557.
use of balances or scales recording pounds of mass (lbm) or
3
recording density in lbm/ft shall not be regarded as noncon-
formance with this standard.
1
1.6.4 The terms density and unit weight are often used
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.05 on Strength and
interchangeably. Density is mass per unit volume whereas unit
Compressibility of Soils.
weight is force per unit volume. In this standard, density is
Current edition approved Nov. 15, 2021. Published December 2021. Original
...
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: D1883 − 16 D1883 − 21
Standard Test Method for
California Bearing Ratio (CBR) of Laboratory-Compacted
1
Soils
This standard is issued under the fixed designation D1883; 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.
1. Scope*
1.1 This test method covers the determination of the California Bearing Ratio (CBR) of pavement subgrade, subbase, and base
course materials from laboratory compacted specimens. The test method is primarily intended for, but not limited to, evaluating
3
the strength of materials having maximum particle size less than ⁄4 in. (19 mm).
3
1.2 When materials having a maximum particle size greater than ⁄4 in. (19 mm) are to be tested, this test method provides for
3
modifying the gradation of the material so that the material used for testing all passes the ⁄4-in. (19-mm) sieve while the total
gravel fraction (material passing the 3-in. (75-mm) sieve and retained on the No. 4 (4.75-mm) sieve) remains the same. While
traditionally this method of specimen preparation has been used to avoid the error inherent in testing materials containing large
particles in the CBR test apparatus, the modified material may have significantly different strength properties than the original
material. However, a large experience database has been developed using this test method for materials for which the gradation
has been modified, and satisfactory design methods are in use based on the results of tests using this procedure.
1.3 Past practice has shown that CBR results for those materials having substantial percentages of particles retained on the No.
4 (4.75 mm) sieve are more variable than for finer materials. Consequently, more trials may be required for these materials to
establish a reliable CBR.
1.4 This test method provides for the determination of the CBR of a material at optimum water content or a range of water
contentcontents from a specified compaction test and a specified dry unit weight. The dry unit weight is usually given as a
percentage of maximum dry unit weight determined by Test Methods D698 or D1557.
1.4.1 The client requesting the CBR test may specify the water content or range of water contents and/or the dry unit weight for
which the CBR is desired.
1.5 The client requesting the test may specify the water content or range of water contents and the dry unit weight for which the
CBR is desired.
1.5 Unless specified otherwise by the requesting client, or unless it has been shown to have no effect on test results for the material
being tested, all specimens shall be soaked prior to penetration.
1
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.05 on Strength and
Compressibility of Soils.
Current edition approved March 1, 2016Nov. 15, 2021. Published March 2016December 2021. Originally approved in 1961. Last previous edition approved in 20142016
as D1883 – 14.D1883 – 16. DOI: 10.1520/D1883-16.10.1520/D1883-21.
*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
---------------------- Page: 1 ----------------------
D1883 − 21
1.7 For the determination of CBR of field in-place materials, see Test Method D4429.
1.6 Units—The values stated in inch-pound units are to be regarded as standard. The SI units given in parentheses are
mathematical conversions, which are provided for information purposes only and are not considered standard. Reporting of test
results in units other than inch-pound units shall not be regarded as nonconformance with this test method.
1.6.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf)
represents a unit of force (weight), while the unit for mass is slugs. The slug unit is not given, unless dynamic (F = ma) calculations
are involved.
1.6.2 The slug unit of mass is almost never used in commercial practice; that is, density, balances, etc. Therefore, the standard unit
for mass in this standard is either kilogram (kg) or gram (g), or both. Also, the equivalent inch-pound unit (slug) is not
given/presented in p
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.