1、Designation: D2168 10 (Reapproved 2018)Standard Practices forCalibration of Laboratory Mechanical-Rammer SoilCompactors1This standard is issued under the fixed designation D2168; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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.1. Scope1.1 These practices for the
3、calibration of mechanical soilcompactors are for use in checking and adjusting mechanicaldevices used in laboratory compacting of soil and soil-aggregate in accordance with Test Methods D698, D1557,Practice D6026, and other methods of a similar nature thatmight specify these practices. Calibration f
4、or use with onepractice does not qualify the equipment for use with anotherpractice.1.2 The weight of the mechanical rammer is adjusted asdescribed in 5.4 and 6.5 in order to provide for the mechanicalcompactor to produce the same result as the manual compactor.1.3 Two alternative procedures are pro
5、vided as follows:SectionPractice A Calibration based on the compaction of aselected soil sample5Practice B Calibration based on the deformation of astandard lead cylinder61.4 If a mechanical compactor is calibrated in accordancewith the requirements of either Practice A or Practice B, it isnot neces
6、sary for the mechanical compactor to meet therequirements of the other practice.1.5 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.5.1 It is common practice in the engineering profession toconcurrently use pounds to
7、represent both a unit of mass (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. This standard
8、has been written using the gravitationalsystem of units when dealing with the inch-pound system. Inthis system, the pound (lbf) represents a unit of force (weight).However, the use of balances or scales recording pounds ofmass (lbm) or the recording of density in lbm/ft3shall not beregarded as a non
9、conformance with this standard.1.6 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, health, and environmental practices and deter-mine the applicability of regu
10、latory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade O
11、rganization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D653 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)D1557 Test Methods fo
12、r Laboratory Compaction Character-istics of Soil Using Modified Effort (56,000 ft-lbf/ft3(2,700 kN-m/m3)D2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of S
13、oil and Rock asUsed in Engineering Design and ConstructionD6026 Practice for Using Significant Digits in GeotechnicalDataE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE145 Specification for Gravity-Convection and Forced-Ventilation Ovens1These practices are under the jurisdiction o
14、fASTM Committee D18 on Soil andRock and are the direct responsibility of Subcommittee D18.03 on Texture,Plasticity and Density Characteristics of Soils.Current edition approved July 1, 2018. Published July 2018. Originally appr-roved in 1990. Last previous edition approved in 2010 as D216810. DOI:10
15、.1520/D2168-10R18.2For referenced ASTM standards, visit the ASTM 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.*A Summary of Changes section appears at th
16、e end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for t
17、heDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13. Significance and Use3.1 Mechanical compactors are commonly used to replacethe hand compactors required for Test Methods D698 andD1557 in cases w
18、here it is necessary to increase production.3.2 The design of mechanical compactors is such that it isnecessary to have a calibration process that goes beyonddetermining the mass and drop of the hammer.NOTE 1The quality of the result produced by this standard isdependent on the competence of the per
19、sonnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria in Practice D3740 are generally considered capable of competentand objective testing/sampling/inspection/and the like. Users of thisstandard are cautioned that compliance with Practice D3740
20、 does not initself assure reliable results. Reliable results depend on many factors;Practice D3740 provides a means of evaluating some of those factors.4. Apparatus4.1 For PracticeA, in addition to the apparatus requirementsspecified in Test Methods D698 and D1557, the following isrequired:4.1.1 Dry
21、ing OvenThermostatically controlled oven, pref-erably of the forced-draft type, meeting the requirements forSpecification E145 and capable of maintaining a uniformtemperature of 140 6 5F (60 6 3C) throughout the dryingchamber.4.2 For Practice B, in addition to the apparatus requirementsspecified in
22、Test Methods D698 and D1557, the following arerequired:4.2.1 Lead Deformation ApparatusA lead deformationapparatus consisting of an anvil, guide collar, and striking pin,as shown in Fig. 1.4.2.2 MicrometerAone-inch (25-mm) outside micrometeror caliper reading to 0.001 in. (0.02 mm), for determining
23、thelength of the lead cylinders. As an alternative, a one-inch(25-mm) dial comparator reading to 0.001 in. (0.02 mm) maybe used to determine either the length of the lead cylinder, orof the complete lead deformation apparatus assembly. Tomeasure the complete assembly, a dial comparator with aminimum
24、 opening of 2 in. (50 mm) is required (see Fig. 2).NOTE 2The use of vernier calipers is not recommended since thevernier calipers can produce erroneous readings if not zeroed correctly, orif the vernier caliper is not of high quality.4.2.3 Guide Sleeve PedestalA guide sleeve pedestal foruse with gui
25、de sleeves used to control the drop of the manualrammers in Test Methods D698 and D1557 (see Fig. 3).4.2.4 Test CylindersA supply of commercially pure leadtest cylinders having individual weights such that the lightestcylinder is within 0.06 g of the heaviest, each having a lengthof 0.675 6 0.005 in
26、. (17.1 6 0.1 mm) and a diameter of 0.3106 0.002 in. (7.87 6 0.05 mm).3A minimum of ten testcylinders is required for the calibration of one mechanicalcompactor. However, depending on circumstances, as many as100 test cylinders may be required.5. ProcedurePractice A5.1 Evaluate the mechanical and ma
27、nual compactors forevidence of wear, malfunction, and need of servicing andadjustment. Clean, adjust, and lubricate the compactors so as tomeet all requirements of the manufacturer, and the applicablemethod under which they will be used and for which themechanical compactor is to be calibrated. Oper
28、ate the compac-tor for a minimum of 25 drops to cause friction in the parts tobecome constant, allowing the rammer to fall on soil or othersoft material.NOTE 3In order to provide satisfactory results, mechanical compac-tors must be in excellent working condition. Improper operation of theraising and
29、 release mechanisms can introduce serious errors.5.2 Obtain approximately 50 lb (23 kg) of soil classified asCL in accordance with Classification D2487. If excessivemoisture is present, dry the soil until it becomes friable. Dryingmay be in air or by use of a drying apparatus such that thetemperatur
30、e of the sample does not exceed 140F (60C). Passthe soil through a No. 4 (4.75-mm) sieve conforming to therequirements of Specification E11. Discard any material re-maining on the sieve, and thoroughly blend the materialpassing the sieve until it is uniform. The material shall then beprepared for co
31、mpaction in accordance with either MethodsD698 or D1557 as appropriate for the mechanical compactorbeing calibrated.NOTE 4The amount of soil used will vary greatly depending on thenumber of water content unit mass determinations required.5.3 Using the soil prepared in accordance with 5.2, deter-mine
32、 optimum moisture and maximum dry unit weight byMethod A of either Test Methods D698 or D1557 or whichevermethod is appropriate for the mechanical compactor beingcalibrated. Prepare one curve using the mechanical compactorand another using the manual compactor. Record the values ofmax, the maximum d
33、ry unit weight obtained with the manualcompactor, and max, the maximum dry unit weight obtainedwith the mechanical compactor.5.4 Determine W, the percentage difference of maximumdry unit weight values for a single set of data (see Section 7).If the absolute value of W is equal to or less than 2.0, t
34、hemechanical compactor is satisfactory for immediate use. If theabsolute value of W is greater than 2.0, then obtain twoadditional sets of data. Use the same soil sample, prepared inaccordance with 5.2, that was used previously. Determine W,the average percentage difference of maximum dry unit massv
35、alues for three sets of data (see Section 7). If the absolutevalue of W is equal to or less than 2.0, the mechanicalcompactor is satisfactory for immediate use. If the absolutevalue of Wis greater than 2.0, then adjust the rammer mass ofthe mechanical compactor in accordance with 5.5. Then securethr
36、ee new values of maxand compute a new value of W.Repeat this procedure until the absolute value of Wis equal toor less than 2.0.5.5 Make changes in the weight of the mechanical hammerwith due consideration to good workmanship. Makeshift modi-fications that could affect the operation of the mechanica
37、lcompactor are not permitted. The maximum permissible varia-tion in the weight of the mechanical hammer as the result of3The sole source of supply of the lead test cylinders known to the committee atthis time is Hornady Manufacturing Co., P.O. Box 1848, Grand Island, Nebr. 68801in lots of 500. If yo
38、u are aware of alternative suppliers, please provide thisinformation to ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.D2168 10 (2018)2calibration is as follows: The total mass added to the ori
39、ginalmass of the hammer as received from the manufacturer mustnot exceed ten percent of its original mass. If it is necessary toadd more than ten percent, the mechanical compactor is to berebuilt or repaired. If the calibration indicates that the mass ofthe original rammer needs to be reduced to les
40、s than 5.5 lbf(2.49 kg) or 10 lbf (4.54 kg) depending on the test methodrammer standard, carefully recheck all equipment and calibra-tions and report the procedure. If removal of mass is stillindicated, the height-of-drop should be adjusted.NOTE 5Graphical procedures are helpful in estimating the co
41、rrectin. mm2.10 53.34178 48158 41112 381.250 31.751.248 31.700.626 15.900.625 15.8812 130.317 8.0514 6.418 3.2116 1.6132 0.790.005 0.130.004 0.100.002 0.050.001 0.02NOTE 1Inside dimension of guide collar should slip easily over raised section of anvil without excessive free play. Anvil should slip e
42、asily insideguide sleeve pedestal without excessive free play.FIG. 1 Lead Deformation ApparatusD2168 10 (2018)3amount of mass to be added or subtracted.5.6 If a larger change than that permitted in 5.5 is found tobe necessary, then improper operation of the mechanicalcompactor is indicated. Evaluate
43、 and adjust the mechanicalcompactor in order to determine and eliminate the cause of themalfunction and repeat the calibration procedure.5.7 Do not use the mechanical compactor if the indicatedweight change still exceeds that permitted in 5.5.6. ProcedurePractice B6.1 Evaluate and adjust the mechani
44、cal and manual com-pactors as described in 5.1 of Practice A.6.2 Deformation by the Manual CompactorObtain thedeformation value for the manual compactor as follows:6.2.1 Select a set of lead cylinders from the same lot orshipment. Remove any burrs from the ends of the leadcylinders using a fine grad
45、e of emery cloth.NOTE 6Deformation of the lead cylinders is affected by changes intemperature. Take precautions to maintain the cylinders within 65F(62.7C) during the calibration of the mechanical compactor and thesecuring of the manual compactor values.6.2.2 Obtain c1, the (initial) micrometer or d
46、ial comparatorreading before impact, following the procedures decribed in6.2.5.6.2.3 Place the base plate of the compaction mold on a rigidfoundation. On the base plate, place the assembled leaddeformation apparatus with the lead cylinder (see Fig. 4) andguide sleeve pedestal in place. Insert the gu
47、ide sleeve of themanual compactor into the recess in the guide sleeve pedestal.Check that the distance from rammer release point to strikingpin contact meets the specified requirements. Apply one dropof the manual rammer with the guide sleeve of the manualcompactor held vertically, so that the ramme
48、r does not strikethe guide sleeve pedestal.6.2.4 Obtain c2, the micrometer or dial comparator readingafter impact, following the procedures described in 6.2.5. Thedifference between dial readings c1and c2is equal to D, thedeformation value.in. mm8 20337625112514 6.418 3.20.001 0.02FIG. 2 Dial Compar
49、atorin. mm2.77 70.42.13 54.1038 1018 3.20.03 0.80.005 0.13NOTE 1This dimension must be equal to the height of the leaddeformation apparatus when assembled with the lead cylinder in place,within a tolerance of 60.01 in. (60.25mm).NOTE 2DiameterAis such that guide sleeve of rammer fits easily intorecess without free play.FIG. 3 Guide Sleeve PedestalFIG. 4 Lead Deformation Apparatus AssemblyD2168 10 (2018)46.2.5 Obtain readings for c1and c2either by:6.2.5.1 Direct measurement of the length of the leadcylinder, using the outside micromete
