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ASTM D1557-12(2021)
Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3 (2,700 kN-m/m3))
Přeložit název
NORMA vydána dne 1.7.2021
Informace o normě:
Označení normy: ASTM D1557-12(2021)
Datum vydání normy: 1.7.2021
Kód zboží: NS-1029268
Počet stran: 13
Přibližná hmotnost: 39 g (0.09 liber)
Země: Americká technická norma
Kategorie: Technické normy ASTM
Kategorie - podobné normy:
Zemní práce. Hloubicí práce. Budování základů. Podzemní práce
Anotace textu normy ASTM D1557-12(2021) :
Keywords:
compaction characteristics, density, impact compaction using modified effort, laboratory tests, modified proctor test, moisture-density curves, soil compaction,, ICS Number Code 93.020 (Earth works. Excavations. Foundation construction. Underground works)
Doplňující informace
| Significance and Use | ||||||||||||||||||||||||||||||||||||||||||||
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5.1?Soil placed as engineering fill (embankments, foundation pads, road bases) is compacted to a dense state to obtain satisfactory engineering properties such as shear strength, compressibility, or permeability. In addition, foundation soils are often compacted to improve their engineering properties. Laboratory compaction tests provide the basis for determining the percent compaction and molding water content needed to achieve the required engineering properties, and for controlling construction to assure that the required compaction and water contents are achieved. Note 3:?The degree of soil compaction required to achieve the
desired engineering properties is often specified as a percentage
of the modified maximum dry unit weight as determined using this
test method. If the required degree of compaction is substantially
less than the modified maximum dry unit weight using this test
method, it may be practicable for testing to be performed using
Test Method and to specify the degree of compaction as a percentage
of the standard maximum dry unit weight. Since more energy is
applied for compaction using this test method, the soil particles
are more closely packed than when D698 is used. The general overall result
is a higher maximum dry unit weight, lower optimum moisture
content, greater shear strength, greater stiffness, lower
compressibility, lower air voids, and decreased permeability.
However, for highly compacted fine-grained soils, absorption of
water may result in swelling, with reduced shear strength and
increased compressibility, reducing the benefits of the increased
effort used for compaction 5.2?During design of an engineered fill,
testing performed to determine shear, consolidation, permeability,
or other properties requires test specimens to be prepared by
compacting the soil at a prescribed molding water content to obtain
a predetermined unit weight. It is common practice to first
determine the optimum water content (wopt) and maximum dry unit weight
(?5.3?Experience indicates that the methods
outlined in 5.2 or the
construction control aspects discussed in 5.1 are extremely difficult to implement
or yield erroneous results when dealing with some soils. The
following subsections describe typical problem soils, the problems
encountered when dealing with such soils and possible solutions for
these problems.
5.3.1?Oversize FractionSoils containing more than 30 % oversize fraction (material retained on the 3/4-in. (19-mm) sieve) are a problem. For such soils, there is no ASTM test method to control their compaction and very few laboratories are equipped to determine the laboratory maximum unit weight (density) of such soils (USDI Bureau of Reclamation, Denver, CO and U.S. Army Corps of Engineers, Vicksburg, MS). Although Test Methods D4914/D4914M and D5030/D5030M determine the field dry unit weight of such soils, they are difficult and expensive to perform. 5.3.1.1?One method to design and control the compaction of such soils is to use a test fill to determine the required degree of compaction and the method to obtain that compaction. Then use a method specification to control the compaction. Components of a method specification typically contain the type and size of compaction equipment to be used, the lift thickness, acceptable range of molding water content, and number of passes. Note 4:?Success in executing the compaction control of an
earthwork project, especially when a method specification is used,
is highly dependent upon the quality and experience of the
contractor and inspector.
5.3.1.2?Another method is to apply the use of density correction factors developed by the USDI Bureau of Reclamation 5.3.1.3?The use of the replacement technique (Test Method D155778, Method D), in which the oversize fraction is replaced with a finer fraction, is inappropriate to determine the maximum dry unit weight, ?5.3.2?DegradationSoils containing particles that degrade during compaction are a problem, especially when more degradation occurs during laboratory compaction than field compaction, the typical case. Degradation typically occurs during the compaction of a granular-residual soil or aggregate. When degradation occurs, the maximum dry-unit weight increases 5.3.2.1?Again for soils subject to degradation, the use of test fills and method specifications may help. Use of replacement techniques is not correct. 5.3.3?Gap GradedGap-graded soils (soils containing many large particles with limited small particles) are a problem because the compacted soil will have larger voids than usual. To handle these large voids, standard test methods (laboratory or field) typically have to be modified using engineering judgement. Note 5:?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 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 depend on many factors;
Practice D3740 provides a
means of evaluating some of those factors.
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| 1. Scope | ||||||||||||||||||||||||||||||||||||||||||||
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1.1?These test methods cover laboratory compaction methods used to determine the relationship between molding water content and dry unit weight of soils (compaction curve) compacted in a 4- or 6-in. (101.6- or 152.4-mm) diameter mold with a 10.00-lbf. (44.48-N) rammer dropped from a height of 18.00 in. (457.2 mm) producing a compactive effort of 56 000 ft-lbf/ft3 (2700 kN-m/m3). Note 1:?The equipment and procedures are the same as proposed
by the U.S. Corps of Engineers in 1945. The modified effort test
(see 3.1.3) is sometimes
referred to as the Modified Proctor Compaction Test.
1.1.1?Soils and soil-aggregate mixtures are to be regarded as natural occurring fine- or coarse-grained soils, or composites or mixtures of natural soils, or mixtures of natural and processed soils or aggregates such as gravel or crushed rock. Hereafter referred to as either soil or material. 1.2?These test methods apply only to soils (materials) that have 30 % or less by mass of their particles retained on the 3/4-in. (19.0-mm) sieve and have not been previously compacted in the laboratory; that is, do not reuse compacted soil. 1.2.1?For relationships between unit weights and molding water contents of soils with 30 % or less by weight of material retained on the 3/4-in. (19.0-mm) sieve to unit weights and molding water contents of the fraction passing the 3/4-in. (19.0-mm) sieve, see Practice D4718/D4718M. 1.3?Three alternative methods are provided. 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 material gradation. 1.3.1?Method A:? 1.3.1.1?Mold4-in. (101.6-mm) diameter. 1.3.1.2?MaterialPassing No. 4 (4.75-mm) sieve. 1.3.1.3?LayersFive. 1.3.1.4?Blows per layer25. 1.3.1.5?UsageMay be used if 25 % or less by mass of the material is retained on the No. 4 (4.75-mm) sieve. However, if 5 to 25 % by mass of the material is retained on the No. 4 (4.75-mm) sieve, Method A can be used but oversize corrections will be required (See 1.4) and there are no advantages to using Method A in this case. 1.3.1.6?Other UseIf this gradation requirement cannot be met, then Methods B or C may be used. 1.3.2?Method B:? 1.3.2.1?Mold4-in. (101.6-mm) diameter. 1.3.2.2?MaterialPassing 3/8-in. (9.5-mm) sieve. 1.3.2.3?LayersFive. 1.3.2.4?Blows per layer25. 1.3.2.5?UsageMay be used if 25 % or less by mass of the material is retained on the 3/8-in. (9.5-mm) sieve. However, if 5 to 25 % of the material is retained on the 3/8-in. (9.5-mm) sieve, Method B can be used but oversize corrections will be required (See 1.4). In this case, the only advantages to using Method B rather than Method C are that a smaller amount of sample is needed and the smaller mold is easier to use. 1.3.2.6?Other UsageIf this gradation requirement cannot be met, then Method C may be used. 1.3.3?Method C:? 1.3.3.1?Mold6-in. (152.4-mm) diameter. 1.3.3.2?MaterialPassing 3/4-in. (19.0-mm) sieve. 1.3.3.3?LayersFive. 1.3.3.4?Blows per layer56. 1.3.3.5?UsageMay be used if 30 % or less (see 1.4) by mass of the material is retained on the 3/4-in. (19.0-mm) sieve. 1.3.4?The 6-in. (152.4-mm) diameter mold shall not be used with Method A or B. Note 2:?Results have been found to vary slightly when a
material is tested at the same compactive effort in different size
molds, with the smaller mold size typically yielding larger values
of unit weight and density 1.4?If
the test specimen contains more than 5 % by mass of oversize
fraction (coarse fraction) and the material will not be included in
the test, corrections must be made to the unit weight and molding
water content of the test specimen or to the appropriate field
in-place unit weight (or density) test specimen using Practice
D4718/D4718M.
1.5?This test method will generally produce a well-defined maximum dry unit weight for non-free draining soils. If this test method is used for free-draining soils the maximum unit weight may not be well defined, and can be less than obtained using Test Methods D4253. 1.6?All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026, unless superseded by these test methods. 1.6.1?For purposes of comparing measured or calculated value(s) with specified limits, the measured or calculated value(s) shall be rounded to the nearest decimal or significant digits in the specified limits. 1.6.2?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 users objectives; 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 these test methods to consider significant digits used in analytical methods for engineering design. 1.7?The values in inch-pound units are to be regarded as the standard. The values stated in SI units are provided for information only, except for units of mass. The units for mass are given in SI units only, g or kg. 1.7.1?It is common practice in the engineering profession to concurrently use pounds to represent both a unit of mass (lbm) and a force (lbf). This implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. These test methods have been written using the gravitational system of units when dealing with the inch-pound system. In this system, the pound (lbf) represents a unit of force (weight). However, the use of balances or scales recording pounds of mass (lbm) or the recording of density in lbm/ft3 shall not be regarded as a nonconformance with this standard. 1.8?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. 1.9?WarningMercury has been designated by EPA and many state agencies as a hazardous material that can cause central nervous system, kidney, and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and EPAs website (http://www.epa.gov/mercury/faq.htm) for additional information. Users should be aware that selling mercury or mercury containing products or both into your state may be prohibited by state law. 1.10?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. |
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| 2. Referenced Documents | ||||||||||||||||||||||||||||||||||||||||||||
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