1、Designation: D1557 12Standard Test Methods forLaboratory Compaction Characteristics of Soil UsingModified Effort (56,000 ft-lbf/ft3(2,700 kN-m/m3)1This standard is issued under the fixed designation D1557; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 T
3、hese test methods cover laboratory compaction meth-ods used to determine the relationship between molding watercontent and dry unit weight of soils (compaction curve)compacted in a 4- or 6-in. (101.6- or 152.4-mm) diameter moldwith a 10.00-lbf. (44.48-N) rammer dropped from a height of18.00 in. (457
4、.2 mm) producing a compactive effort of 56 000ft-lbf/ft3(2700 kN-m/m3).NOTE 1The equipment and procedures are the same as proposed bythe U.S. Corps of Engineers in 1945. The modified effort test (see 3.1.2)is sometimes referred to as the Modified Proctor Compaction Test.1.1.1 Soils and soil-aggregat
5、e mixtures are to be regarded asnatural occurring fine- or coarse-grained soils, or composites ormixtures of natural soils, or mixtures of natural and processedsoils or aggregates such as gravel or crushed rock. Hereafterreferred to as either soil or material.1.2 These test methods apply only to soi
6、ls (materials) thathave 30 % or less by mass of their particles retained on the34-in. (19.0-mm) sieve and have not been previously com-pacted in the laboratory; that is, do not reuse compacted soil.1.2.1 For relationships between unit weights and moldingwater contents of soils with 30 % or less by w
7、eight of materialretained on the34-in. (19.0-mm) sieve to unit weights andmolding water contents of the fraction passing the34-in.(19.0-mm) sieve, see Practice D4718.1.3 Three alternative methods are provided. The methodused shall be as indicated in the specification for the materialbeing tested. If
8、 no method is specified, the choice should bebased 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 thematerial is retained on
9、the No. 4 (4.75-mm) sieve. However, if5 to 25 % by mass of the material is retained on the No. 4(4.75-mm) sieve, Method A can be used but oversize correc-tions will be required (See 1.4) and there are no advantages tousing Method A in this case.1.3.1.6 Other UseIf this gradation requirement cannot b
10、emet, 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 MaterialPassing38-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 thematerial is retained on the38-in. (9.5-mm) sieve. However, if5 t
11、o 25 % of the material is retained on the38-in. (9.5-mm)sieve, Method B can be used but oversize corrections will berequired (See 1.4). In this case, the only advantages to usingMethod B rather than Method C are that a smaller amount ofsample is needed and the smaller mold is easier to use.1.3.2.6 O
12、ther UsageIf this gradation requirement cannotbe 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 MaterialPassing34-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)bymass of the material is
13、retained on the34-in. (19.0-mm) sieve.1.3.4 The 6-in. (152.4-mm) diameter mold shall not be usedwith Method A or B.NOTE 2Results have been found to vary slightly when a material istested at the same compactive effort in different size molds, with thesmaller mold size typically yielding larger values
14、 of unit weight anddensity (1).21.4 If the test specimen contains more than 5 % by mass ofoversize fraction (coarse fraction) and the material will not be1These test methods are under the jurisdiction of ASTM Committee D18 on Soiland Rock and are the direct responsibility of Subcommittee D18.03 on T
15、exture,Plasticity and Density Characteristics of Soils.Current edition approved May 1, 2012. Published June 2012. Originallyapproved in 1958. Last previous edition approved in 2009 as D155709. DOI:10.1520/D1557-12.2The boldface numbers in parentheses refer to the list of references at the end ofthis
16、 standard.1*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.included in the test, corrections must be made to the unitweight and molding water content of the test specim
17、en or to theappropriate field in-place unit weight (or density) test specimenusing Practice D4718.1.5 This test method will generally produce a well-definedmaximum dry unit weight for non-free draining soils. If thistest method is used for free-draining soils the maximum unitweight may not be well d
18、efined, and can be less than obtainedusing Test Methods D4253.1.6 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026, unless superseded by these test methods.1.6.1 For purposes of comparing measured or calculatedvalue(s)
19、 with specified limits, the measured or calculatedvalue(s) shall be rounded to the nearest decimal or significantdigits 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 theindustry standard. In addition, they
20、are representative of thesignificant digits that generally should be retained. The proce-dures used do not consider material variation, purpose forobtaining the data, special purpose studies, or any consider-ations for the users objectives; it is common practice toincrease or reduce significant digi
21、ts of reported data to becommensurate with these considerations. It is beyond the scopeof these test methods to consider significant digits used inanalytical methods for engineering design.1.7 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are ma
22、thematicalconversions to SI units that are provided for information onlyand are not considered standard, except for units of mass. Theunits for mass are given in SI units only, g or kg.1.7.1 It is common practice in the engineering profession toconcurrently use pounds to represent both a unit of mas
23、s (lbm)and a force (lbf). This implicitly combines two separatesystems of units; that is, the absolute system and the gravita-tional system. It is scientifically undesirable to combine the useof two separate sets of inch-pound units within a singlestandard. These test methods have been written using
24、 thegravitational system of units when dealing with the inch-poundsystem. In this system, the pound (lbf) represents a unit of force(weight). However, the use of balances or scales recordingpounds of mass (lbm) or the recording of density in lbm/ft3shall not be regarded as a nonconformance with this
25、 standard.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.9 W
26、arningMercury has been designated by EPA andmany state agencies as a hazardous material that can causecentral nervous system, kidney, and liver damage. Mercury, orits vapor, may be hazardous to health and corrosive tomaterials. Caution should be taken when handling mercury andmercury containing prod
27、ucts. See the applicable product Ma-terial Safety Data Sheet (MSDS) for details and EPAs website(http:/www.epa.gov/mercury/faq.htm) for additional informa-tion. Users should be aware that selling mercury or mercurycontaining products or both into your state may be prohibitedby state law.2. Reference
28、d Documents2.1 ASTM Standards:3C127 Test Method for Density, Relative Density (SpecificGravity), and Absorption of Coarse AggregateC136 Test Method for Sieve Analysis of Fine and CoarseAggregatesC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsD653
29、Terminology Relating to Soil, Rock, and ContainedFluidsD698 Test Methods for Laboratory Compaction Character-istics of Soil Using Standard Effort (12 400 ft-lbf/ft3(600kN-m/m3)D854 Test Methods for Specific Gravity of Soil Solids byWater PycnometerD2168 Practices for Calibration of Laboratory Mechan
30、ical-Rammer Soil CompactorsD2216 Test Methods for Laboratory Determination of Wa-ter (Moisture) Content of Soil and Rock by MassD2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D2488 Practice for Description and Identification of Soils(Visual-Man
31、ual Procedure)D3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4220 Practices for Preserving and Transporting SoilSamplesD4253 Test Methods for Maximum Index Density and UnitWeight of Soils Using a
32、 Vibratory TableD4718 Practice for Correction of Unit Weight and WaterContent for Soils Containing Oversize ParticlesD4753 Guide for Evaluating, Selecting, and SpecifyingBalances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD4914 Test Methods for Density and Unit Weigh
33、t of Soiland Rock in Place by the Sand Replacement Method in aTest PitD5030 Test Method for Density of Soil and Rock in Placeby the Water Replacement Method in a Test PitD6026 Practice for Using Significant Digits in GeotechnicalDataD6913 Test Methods for Particle-Size Distribution (Grada-tion) of S
34、oils Using Sieve AnalysisE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE319 Practice for the Evaluation of Single-Pan MechanicalBalancesIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System3For referenced ASTM standards, visit the ASTM
35、website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.D1557 1223. Terminology3.1 Definitions: See Terminology D653 for general defini-tions.3.1.1 molding water co
36、ntent, nthe water content of thesoil (material) specimen in the mold after it has been reconsti-tuted and compacted.3.1.2 modified effortin compaction testing, the term forthe 56 000 ft-lbf/ft3(2700 kN-m/m3) compactive effort appliedby the equipment and methods of this test.3.1.3 modified maximum dr
37、y unit weight, gd,max(lbf/ft3(kN/m3)in compaction testing, the maximum value defined bythe compaction curve for a compaction test using modifiedeffort.3.1.4 modified optimum water content, wopt(%)in com-paction testing, the water content at which the soil can becompacted to the maximum dry unit weig
38、ht using modifiedcompactive effort.3.2 Definitions of Terms Specific to This Standard:3.2.1 oversize fraction (coarse fraction), PC(%)the por-tion of total specimen not used in performing the compactiontest; it may be the portion of total specimen retained on the No.4 (4.75-mm) sieve in Method A,38-
39、in. (9.5-mm) sieve inMethod B, or34-in. (19.0-mm) sieve in Method C.3.2.2 test fraction (finer fraction), PF(%)the portion ofthe total specimen used in performing the compaction test; itmay be fraction passing the No. 4 (4.75-mm) sieve in MethodA, passing the38-in. (9.5-mm) sieve in Method B, or pas
40、singthe34-in. (19.0-mm) sieve in Method C.4. Summary of Test Method4.1 A soil at a selected molding water content is placed infive layers into a mold of given dimensions, with each layercompacted by 25 or 56 blows of a 10.00-lbf (44.48-N) rammerdropped from a distance of 18.00 in. (457.2 mm), subjec
41、tingthe soil to a total compactive effort of about 56 000 ft-lbf/ft3(2700 kN-m/m3). The resulting dry unit weight is determined.The procedure is repeated for a sufficient number of moldingwater contents to establish a relationship between the dry unitweight and the molding water content for the soil
42、. This data,when plotted, represent a curvilinear relationship known as thecompaction curve. The values of optimum water content andmodified maximum dry unit weight are determined from thecompaction curve.5. Significance and Use5.1 Soil placed as engineering fill (embankments, founda-tion pads, road
43、 bases) is compacted to a dense state to obtainsatisfactory engineering properties such as shear strength,compressibility, or permeability. In addition, foundation soilsare often compacted to improve their engineering properties.Laboratory compaction tests provide the basis for determiningthe percen
44、t compaction and molding water content needed toachieve the required engineering properties, and for controllingconstruction to assure that the required compaction and watercontents are achieved.NOTE 3The degree of soil compaction required to achieve the desiredengineering properties is often specif
45、ied as a percentage of the modifiedmaximum dry unit weight as determined using this test method. If therequired degree of compaction is substantially less than the modifiedmaximum dry unit weight using this test method, it may be practicable fortesting to be performed using Test Method D698 and to s
46、pecify the degreeof compaction as a percentage of the standard maximum dry unit weight.Since more energy is applied for compaction using this test method, thesoil particles are more closely packed than when D698 is used. Thegeneral overall result is a higher maximum dry unit weight, loweroptimum moi
47、sture content, greater shear strength, greater stiffness, lowercompressibility, lower air voids, and decreased permeability. However, forhighly compacted fine-grained soils, absorption of water may result inswelling, with reduced shear strength and increased compressibility,reducing the benefits of
48、the increased effort used for compaction (2). Useof D698, on the other hand, allows compaction using less effort andgenerally at a higher optimum moisture content. The compacted soil maybe less brittle, more flexible, more permeable, and less subject to effectsof swelling and shrinking. In many appl
49、ications, building or constructioncodes may direct which test method, D698 or this one, should be usedwhen specifying the comparison of laboratory test results to the degree ofcompaction of the in-place soil in the field.5.2 During design of an engineered fill, testing performed todetermine shear, consolidation, permeability, or other proper-ties requires test specimens to be prepared by compacting thesoil at a prescribed molding water content to obtain a prede-termined unit weight. It is common practice to first determinethe optimum water
