1、Designation:D1557121Standard 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 the
2、 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 U.S.Department of Defense.1NOTEEditorially co
3、rrected variable for Eq A1.2 in July 2015.1.Scope*1.1 These 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
4、-N)rammer dropped from a height of18.00 in.(457.2 mm)producing a compactive effort of 56 000ft-lbf/ft3(2700 kN-m/m3).NOTE1The equipment and procedures are the same as proposed bythe U.S.Corps of Engineers in 1945.The modified effort test(see 3.1.3)is sometimes referred to as the Modified Proctor Com
5、paction Test.1.1.1 Soils and soil-aggregate 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.
6、2 These test methods apply only to soils(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 o
7、f soils with 30%or less by weight 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 m
8、aterialbeing tested.If 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 i
9、s retained on 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
10、 bemet,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 to 25%of t
11、he 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 Other UsageIf thi
12、s 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 retained on the34-in.(19
13、.0-mm)sieve.1.3.4 The 6-in.(152.4-mm)diameter mold shall not be usedwith Method A or B.NOTE2Results have been found to vary slightly when a material istested at the same compactive effort in different size molds,with the1These test methods are under the jurisdiction ofASTM Committee D18 on Soiland R
14、ock and are the direct responsibility of Subcommittee D18.03 on Texture,Plasticity and Density Characteristics of Soils.Current edition approved May 1,2012.Published June 2012.Originallyapproved in 1958.Last previous edition approved in 2007 as D1557 09.DOI:10.1520/D1557-12.*A Summary of Changes sec
15、tion appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 smaller mold size typically yielding larger values of unit weight anddensity(1).21.4 If the test specimen contains more than 5%by mass ofoversize frac
16、tion(coarse fraction)and the material will not beincluded in the test,corrections must be made to the unitweight and molding water content of the test specimen 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 defined,and can be less than obtainedusing Test
