1、Designation: D 2168 02aStandard Test Methods forCalibration of Laboratory Mechanical-Rammer SoilCompactors1This standard is issued under the fixed designation D 2168; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 These test methods for the calibration
3、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 D 698, D 1557 andother methods of a similar nature which might specify thismethod. Calibration for use with one method does no
4、t qualifythe equipment for use with another method.1.2 The weight of the mechanical rammer is adjusted asdescribed in 5.4 and 6.5 in order to provide that the mechanicalcompactor will produce the same result as the manual com-pactor.1.3 Two alternative procedures are provided as follows:SectionTest
5、Method A Calibration based on the compaction of aselected soil sample5Test Method B Calibration based on the deformation of astandard lead cylinder61.4 If a mechanical compactor is calibrated in accordancewith the requirements of either Test Method A or Test MethodB, it is not necessary for it to me
6、et the requirements of the othermethod.1.5 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibilit
7、y 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.2. Referenced Documents2.1 ASTM Standards:D 653 Terminology Relating to Soil, Rock, and ContainedFluids2D 698 Test Method for Laboratory Compac
8、tion Character-istics of Soil Using Standard Effort (12 400 ft-lbf/ft3(600kn-m/m3)2D 1557 Test Method for Laboratory Compaction Character-istics of Soil Using Modified Effort (56 000 ft-lbf/ft3(2700kn-m/m3)2D 2487 Classification of Soils for Engineering Purposes(Unified Soil Classification System)2D
9、 3740 Practice for Agencies Engaged in the Testing and/orInspection of Soil and Rock as Used Ingineering Designand Construction2E11 Specification for Wire-Cloth Sieves for Testing Pur-poses3E 145 Specification for Gravity-Convection and Forced-Ventilation Ovens43. Significance and Use3.1 Mechanical
10、compactors are commonly used to replacethe hand compactors required for Test Methods D 698 andD 1557 in cases where 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 o
11、f the hammer.NOTE 1The quality of the result produced by this standard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria is Practice D 3740 are generally considered capable of competentand objective t
12、esting/sampling/inspection/and the like. Users of thisstandard are cautioned that compliance with Practice D 3740 does not initself assure reliable results. Reliable results depend on many factors;Practice D 3740 provides a means of evaluating some of those factors.1These test methods are under the
13、jurisdiction of ASTM Committee D18 on Soiland Rock and are the direct responsibility of Subcommittee D18.03 on Texture,Plasticity and Density Characteristics of Soils.Current edition approved Nov. 10, 2002. Published January 2003. Originallyapprroved in 1990. Last previous edition D 2168 02.2Annual
14、Book of ASTM Standards, Vol 04.08.3Annual Book of ASTM Standards, Vol 14.02.4Annual Book of ASTM Standards, Vol 14.04.1*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.4
15、. Apparatus4.1 For Test Method A, in addition to the apparatus require-ments specified in Test Methods D 698 and D 1557, thefollowing is required:4.1.1 Drying OvenThermostatically controlled oven,preferably of the forced-draft type, meeting the requirementsfor Specification E 145 and capable of main
16、taining a uniformtemperature of 140 6 5F (60 6 3C) throughout the dryingchamber.4.2 For Test Method B, in addition to the apparatus require-ments specified in Test Methods D 698 and D 1557, thefollowing are required:4.2.1 Lead Deformation ApparatusA lead deformationapparatus consisting of an anvil,
17、guide collar, and striking pin,as shown in Fig. 1.4.2.2 MicrometerA 1-in. or 25-mm outside micrometercaliper reading to 0.001 in. or 0.02 mm, for determining thelength of the lead cylinders. As an alternative, a dial compara-tor of equal accuracy may be used to determine either thelength of the lead
18、 cylinder, or of the complete lead deformationapparatus assembly. In order to measure the complete assem-bly, a dial comparator with a minimum opening of 2 in. (51mm) and a travel of 1 in. (25 mm) is required (see Fig. 2).NOTE 2The use of vernier calipers is not recommended since they canproduce err
19、oneous readings if not zeroed correctly of if the vernier caliperis not of high quality.4.2.3 Guide Sleeve PedestalA guide sleeve pedestal foruse with guide sleeves used to control the drop of the manualrammers in Test Methods D 698 and D 1557 (see Fig. 3).4.2.4 Test CylindersA supply of commerciall
20、y 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. (17.1 6 0.1 mm) and a diameter of 0.3106 0.002 in. (7.87 6 0.05 mm).5A minimum of ten testcylinders is required for the calibration of one mec
21、hanicalcompactor. However, depending on circumstances, as many as100 test cylinders may be required.5. ProcedureTest Method A5.1 Thoroughly inspect the mechanical and manual compac-tors for evidence of wear, malfunction, and need of servicingand adjustment. Clean, adjust, and lubricate the compactor
22、s soas to meet all requirements of the manufacturer, and theapplicable method under which they will be used and for whichthe mechanical compactor is to be calibrated. Operate thecompactor for a minimum of 25 drops to cause friction in theparts to become constant, allowing the rammer to fall on soil
23、orother soft material.NOTE 3In order to provide satisfactory results, mechanical compac-tors must be in excellent working condition. Improper operation of theraising and release mechanisms can introduce serious errors.5.2 Obtain approximately 50 lb (23 kg) of soil classified asCL in accordance with
24、Classification D 2487. If excessivemoisture is present, dry the soil until it becomes friable. Dryingmay be in air or by use of a drying apparatus such that thetemperature of the sample does not exceed 140F (60C). Passthe soil through a No. 4 (4.75-mm) sieve conforming to therequirements of Specific
25、ation 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 compaction in accordance with either MethodsD 698 or D 1557 as appropriate for the mechanical compactorbeing calibrated.NOTE 4The am
26、ount 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 optimum moisture and maximum dry unit weight byMethod A of either Test Methods D 698 or D 1557 or which-ever method is appropri
27、ate for the mechanical compactor beingcalibrated. Prepare one curve using the mechanical compactorand another using the manual compactor. Record the values ofgmax, the maximum dry unit weight obtained with the manualcompactor, and g8max, the maximum dry unit weight obtainedwith the mechanical compac
28、tor.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, themechanical compactor is satisfactory for immediate use. If theabsolute value of W is greater than 2.0, then obtain twoa
29、dditional 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 massvalues for three sets of data (see Section 7). If the absolutevalue of W is equal to or less than 2.0, the mechanicalcompa
30、ctor is satisfactory for immediate use. If the absolutevalue of Wis greater than 2.0, then adjust the rammer massof the mechanical compactor in accordance with 5.5. Thensecure three new values of g8maxand compute a new value ofW. Repeat this procedure until the absolute value of Wis equalto or less
31、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 mechanicalcompactor are not permitted. The maximum permissible varia-tion in the weight of the mechanical hammer as the result o
32、fcalibration is as follows: The total mass added to the originalmass 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.NOTE 5This assumes that some mass
33、 has been added to the rammeras received from the manufacturer. Normally, mass will have to be addedto the original rammer. If the calibration indicates that the mass of theoriginal rammer needs to be reduced to less than 5.5 lbf (2.49 kg) or 10lbf (4.54 kg) depending on the test method rammer stand
34、ard, carefullyrecheck all equipment and calibrations and report the procedure. IFremoval of mass is still indicated, the height-of-drop should be adjusted.5Lead test cylinders are available from the Hornady Manufacturing Co., P.O.Box 1848, Grand Island, Nebr. 68801 in lots of 500.D 2168 02a2NOTE 6Gr
35、aphical procedures are helpful in estimating the correctamount 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. Carefully inspect and adjust the me-chanical compactor in order
36、 to discover and eliminate the causeof the malfunction 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. ProcedureMethod B6.1 Inspect and adjust the mechanical and manual compac-tors as described in 5.1 o
37、f Method A.in. 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
38、slip easily insideguide sleeve pedestal without excessive free play.FIG. 1 Lead Deformation ApparatusD 2168 02a36.2 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 f
39、rom the ends of the leadcylinders using a fine grade of emery cloth.NOTE 7Deformation 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 va
40、lues.6.2.2 Obtain c1, the (initial) micrometer or dial 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.
41、4) andguide sleeve pedestal in place. Insert the guide 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
42、 manualcompactor held vertically, so that the rammer 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.6.2.5 Obt
43、ain readings for c1and c2either by:6.2.5.1 Direct measurement of the length of the lead cylin-der, using the outside micrometer caliper or an equivalent dialcomparator.6.2.5.2 Obtaining a measurement of the assembled defor-mation apparatus, secured by placing it in the dial comparatorso that the top
44、 center of the14-in. (6.4-mm) steel ball of thestriking pin is directly under the tip of the dial stem6.2.6 Repeat 6.2.2-6.2.5 using an unused lead cylinder foreach determination until five deformation values are obtainedthat do not vary more than 2.0 % from D, the average value;that is, the absolut
45、e value of v1must be less than 2.0 for the fivein. mm8 20337625112514 6.418 3.20.001 0.02FIG. 2 Dial Comparatorin. 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
46、 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 AssemblyD 2168 02a4values selected (see 7.2). The deformation value for the manualmethod shall be taken as D.6
47、.3 Deformation by the Mechanical CompactorObtainthe deformation value (change in height) of the lead cylinderby the mechanical compactor as follows:6.3.1 Select a set of at least five lead cylinders from thesame lot or shipment. Remove any burrs from the ends of thelead cylinders using a fine grade
48、emery cloth (see Note 7).6.3.2 Place the assembled lead deformation apparatus on thebase of the mechanical compactor at such location that thestriking pin will be centered on the face of the rammer at themoment of contact of the two.6.3.3 Obtain the average deformation value D8 for themechanical com
49、pactor using the same procedure specified in6.2, except do not use the guide sleeve pedestal. The mechani-cal compactor must operate in the normal manner so as to liftthe rammer from the striking pin contact elevation to thespecified release height. Raising and releasing the rammermanually or by any procedure other than that of normalautomatic operation is prohibited.6.3.4 Repeat 6.3.2 and 6.3.3 on remaining lead cylinders inset6.4 Calculate v2, the percentage difference of the averagedeformation value, using the mechanical rammer, fro
