ASTM D7382-20
(Test Method)Standard Test Methods for Determination of Maximum Dry Unit Weight of Granular Soils Using a Vibrating Hammer
Standard Test Methods for Determination of Maximum Dry Unit Weight of Granular Soils Using a Vibrating Hammer
SIGNIFICANCE AND USE
5.1 For many cohesionless, free-draining soils, the maximum dry unit weight is one of the key components in evaluating the state of compactness of a given soil mass that is either naturally occurring or is constructed (fill).
5.2 Soil placed as an engineered fill is compacted to a dense state to obtain satisfactory engineering properties such as shear strength, compressibility, permeability, or combinations thereof. Also, foundation soils are often compacted to improve their engineering properties. Laboratory compaction tests provide the basis for determining the percent compaction and water content needed at the time of compaction to achieve the required engineering properties, and for controlling construction to ensure that the required unit weights and water contents are achieved.
5.3 It is generally recognized that percent compaction is a good indicator of the state of compactness of a given soil mass. However, the engineering properties, such as strength, compressibility, and permeability of a given soil, compacted by various methods to a given state of compactness can vary considerably. Therefore, considerable engineering judgment must be used in relating the engineering properties of soil to the state of compactness.
5.4 Experience indicates that the construction control aspects discussed in 5.2 are extremely difficult to implement or yield erroneous results when dealing with certain soils. Subsections 5.4.1, 5.4.2, and 5.4.3 describe typical problem soils, the problems encountered when dealing with such soils, and possible solutions to these problems.
5.4.1 Degradation—Soils containing particles that degrade during compaction are a problem, especially when more degradation occurs during laboratory compaction than field compaction, as is typical. Degradation typically occurs during the compaction of a granular-residual soil or aggregate. When degradation occurs, the maximum dry unit weight increases4 so that the laboratory maximum value is not rep...
SCOPE
1.1 These test methods cover the determination of the maximum dry unit weight of granular soils. A vibrating hammer is used to impart a surcharge and compactive effort to the soil specimen. Further, an optional calculation is presented to determine the approximate water content range for effective compaction of granular soils based on the measured maximum dry density and specific gravity.
1.2 These test methods apply to primarily granular, free-draining soils for which impact compaction does not yield a clear optimum water content. Specifically, these test methods apply to soils:
1.2.1 with up to 35 %, by dry mass, passing a No. 200 (75-μm) sieve if the portion passing the No. 40 (425-μm) sieve is nonplastic;
1.2.2 with up to 15 %, by dry mass, passing a No. 200 (75-μm) sieve if the portion passing the No. 40 (425-μm) sieve exhibits plastic behavior.
1.3 Further, due to limitations of the testing equipment, and the available oversize correction procedures these test methods apply to soils in which:
1.3.1 less than 30 %, by dry mass, is retained on the 3/4-in. (19.0-mm) sieve, or in which
1.3.2 100 %, by dry mass, passes the 2-in. (50-mm) sieve.
1.4 These test methods will typically produce a higher maximum dry unit weight for the soils specified in 1.2.1 and 1.2.2 than that obtained by impact compaction in which a well-defined moisture-density relationship is not apparent. However, for some soils containing more than 15 % fines, the use of impact compaction (Test Methods D698 or D1557) may be useful in evaluating what is an appropriate maximum index unit weight.
1.5 Four alternative test methods are provided, with the variation being in saturated versus dry specimens and mold size. The method used shall be as indicated in the specification for the material being tested. If no method is specified, the choice should be based on the maximum particle size of the material.
1.5.1 Method 1A—Using satu...
General Information
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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: D7382 − 20
Standard Test Methods for
Determination of Maximum Dry Unit Weight of Granular
1
Soils Using a Vibrating Hammer
This standard is issued under the fixed designation D7382; 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.
1. Scope* size.The method used shall be as indicated in the specification
for the material being tested. If no method is specified, the
1.1 These test methods cover the determination of the
choice should be based on the maximum particle size of the
maximum dry unit weight of granular soils. A vibrating
material.
hammer is used to impart a surcharge and compactive effort to
1.5.1 Method 1A—Using saturated material and a 6-in.
the soil specimen. Further, an optional calculation is presented
(152.4-mm) diameter mold; applicable for materials with
to determine the approximate water content range for effective
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maximum particle size of ⁄4-in. (19-mm) or less, or with 30%
compaction of granular soils based on the measured maximum
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or less, by dry mass, retained on the ⁄4-in. (19-mm) sieve.
dry density and specific gravity.
1.5.2 Method 1B—Using saturated material and an 11-in.
1.2 These test methods apply to primarily granular, free-
(279.4-mm) diameter mold; applicable for materials with
draining soils for which impact compaction does not yield a
maximum particle size of 2-in. (50-mm) or less
clear optimum water content. Specifically, these test methods
1.5.3 Method 2A—Using oven-dry material and a 6-in.
apply to soils:
(152.4-mm) diameter mold; applicable for materials with
1.2.1 with up to 35%, by dry mass, passing a No. 200
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maximum particle size of ⁄4-in. (19-mm) or less, or with 30%
(75-µm) sieve if the portion passing the No. 40 (425-µm) sieve
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or less, by dry mass, retained on the ⁄4-in. (19-mm) sieve.
is nonplastic;
1.2.2 with up to 15%, by dry mass, passing a No. 200
1.5.4 Method 2B—Using oven-dry material and an 11-in.
(75-µm) sieve if the portion passing the No. 40 (425-µm) sieve
(279.4-mm) diameter mold; applicable for materials with
exhibits plastic behavior.
maximum particle size of 2-in. (50-mm) or less.
1.5.5 It is recommended that both the saturated and dry
1.3 Further, due to limitations of the testing equipment, and
theavailableoversizecorrectionproceduresthesetestmethods methods (Methods 1A and 2A, or 1B and 2B) be performed
apply to soils in which: when beginning a new job or encountering a change in soil
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1.3.1 less than 30%, by dry mass, is retained on the ⁄4-in. type, as one method or the other may result in a higher value
(19.0-mm) sieve, or in which for the maximum dry unit weight. While the dry method is
1.3.2 100%, by dry mass, passes the 2-in. (50-mm) sieve. often preferred for convenience and because results can be
obtained more quickly, as a general rule, the saturated method
1.4 These test methods will typically produce a higher
should be used if it proves to produce a significantly higher
maximum dry unit weight for the soils specified in 1.2.1 and
value for maximum dry unit weight.
1.2.2 than that obtained by impact compaction in which a
well-defined moisture-density relationship is not apparent.
NOTE 1—Results have been found to vary slightly when a material is
However, for some soils containing more than 15% fines, the
tested at the same compaction effort in different size molds.
use of impact compaction (Test Methods D698 or D1557) may
1.6 If the test specimen contains more than 5% by mass of
be useful in evaluating what is an appropriate maximum index
oversize material (coarse fraction) and the material will not be
unit weight.
included in the test, corrections must be made to the unit
1.5 Four alternative test methods are provided, with the
weight and water content of the test specimen or to the
variation being in saturated versus dry specimens and mold
appropriate field in-place density test specimen using Practice
D4718.
NOTE2—Methods1Aand2A(withthecorrectionprocedureofPractice
1 D4718,ifappropriate),havebeenshowntoprovideconsistentresultswith
ThesetestmethodsareunderthejurisdictionofASTMCommitteeD18onSoil
Methods 1B and 2B for materials with 30% or less, by dry mass retained
and Rock and are the direct responsibility of Subcommittee D18.03 on Texture,
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on the ⁄4-in. (19-mm) sieve. Therefore, for ease of operations, it is
Plasticity and Density Characteristics of Soils.
recommended to use Method 1A or 2A, unless Method 1B or 2B is
CurrenteditionapprovedJuly1,2020.PublishedJuly
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