1、Designation: D 1561 92 (Reapproved 2005)e1Standard Practice forPreparation of Bituminous Mixture Test Specimens byMeans of California Kneading Compactor1This standard is issued under the fixed designation D 1561; the number immediately following the designation indicates the year oforiginal adoption
2、 or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEAdjunct references were corrected editorially in April 2006.1. Scope1.1 The pract
3、ice covers the preparation of test specimens ofbituminous paving mixtures by means of a mechanical com-pactor that imparts a kneading action to the test specimens bya series of individual impressions made with a ram.1.2 This standard does not purport to address all of thesafety problems, if any, ass
4、ociated 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.1.3 The values stated in acceptable metric units are to beregarded as the standard.2. Referenced Do
5、cuments2.1 ASTM Standards:2D 1560 Test Methods for Resistance to Deformation andCohesion of Bituminous Mixtures by Means of HveemApparatusD 4753 Specification for Evaluating, Selecting, and Speci-fying Balances and Scales for Use in Soil, Rock andConstruction Materials Testing2.2 ASTM Adjuncts:Calif
6、ornia Kneading Compactor33. Significance and Use3.1 This practice can be used to prepare cylindrical speci-mens of bituminous mix for subsequent testing. The procedureincorporates the use of the California Kneading Compactor inan attempt to duplicate the kneading action that is provided bythe equipm
7、ent now being used for the compaction of asphaltconcrete pavement.4. Apparatus4.1 California Kneading CompactorMechanical knead-ing compactor, as shown in Fig. 1,3for consolidating testspecimens.NOTE 1Kneading compactors, which on calibration develop a tracecurve similar to that of the California kn
8、eading compactor, shall beconsidered acceptable under this test method. Alternatively, any kneadingcompactor capable of fabricating specimens that will show stabilometervalues equivalent to those obtained from the California kneading com-pactor shall be acceptable for use under this test method. The
9、 supplier hasthe responsibility of furnishing those substantiating data for his device.NOTE 2Curves are considered within calibration when they show thesame peak pressure and dwell time in load time tract obtained in thecalibration procedure.NOTE 3This compactor shall be considered in calibration wh
10、en thepeak momentary load applied to a test specimen is held within 65%ofthe intended foot pressure (within the range from 2.4 to 3.4 MPa) (350 to500 psi).NOTE 4The stabilometer values from replicate specimens fabricatedby this Practice D 1561 and tested in accordance with Test MethodsD 1560, shall
11、fall within a range of 3 units for all dense-graded bituminousmixtures containing aggregates not larger than 12.7 mm (12 in.) and withina range of 4 units for coarser graded bituminous mixtures containing up to25.4-mm (1-in.) maximum size aggregates.4.2 Compactor FootAram having a face shaped as sho
12、wnin Fig. 2, and having an area of approximately 20.059 cm2(3.1in.2).4.3 Mold Holder, Funnel, and Feeder Trough, as shown inFig. 3.1This practice is under the jurisdiction of ASTM Committee D04 on Road andPaving Materials and is the direct responsibility of Subcommittee D04.20 onMechanical Tests of
13、Bituminous Mixes.Current edition approved Dec. 1, 2005. Published December 2005. Originallyapproved in 1958. Last previous edition approved in 2000 as D 1561 92 (2000).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual
14、 Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Blueprints of detailed drawings of the apparatus illustrated in Fig. 1 areavailable from ASTM International Headquarters. Request Adjunct No. ADJD1561.Original adjunct produced in 1960.1Copyri
15、ght ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.4 MoldsMolding cylinders, 101.6 6 0.13 mm (4 60.005 in.) in inside diameter by 127 mm (5 in.) in height. Aminimum of three such compaction molds is recommended.4.5 RodRound-nose steel rod, 9
16、.5 mm (38 in.) in diameterby 406.4 mm (16 in.) long.4.6 Paper DisksHeavy paper disks, 101.6 mm (4 in.) indiameter.4.7 ShimSteel shim, 6.4 mm (14 in.) thick, 19.1 mm (34in.) wide, and 63.5 mm (212 in.) long.4.8 Metal FollowersTwo metal followers, 101.2 mm(3.985 in.) in diameter; one 139.7 mm (5.5 in.
17、) high, the other38.1 mm (1.5 in.) high.4.9 Testing MachineA compression testing machine hav-ing a minimum capacity of 22 kN (50 000 lbf).4.10 OvensElectric ovens capable of maintaining tem-peratures of up to 163C (325F).4.11 BalanceA balance having a minimum capacity of 5kg and meeting the requirem
18、ents of Specification D 4753 for abalance with 0.01-g readability.4.12 Sample Splitter, riffle-type, or equivalent.4.13 Sample Mixing ApparatusUse suitable equipment.Hand mixing is permissible, but mechanical mixing is recom-mended.4.14 Miscellaneous ApparatusThermometers, trowels,pans, spatulas, sc
19、oops, gloves, and metal pans.5. Test Specimens5.1 Selection of Bitumen Content for SpecimensThe op-timum amount of bitumen for the aggregate may be determinedby the method commonly employed by the laboratory.5.2 Preparation of Mixtures:5.2.1 Obtain a sieve analysis on the fine and coarse aggre-gate
20、(aggregate shall be separated by means of a 4.75-mm (No.4) sieve). Separate the aggregate into the various size fractionsnecessary for accurately recombining into test mixtures con-forming to specified grading requirements.5.2.2 Combine the moisture-free aggregates into batchesweighing 1200 g. (Ever
21、y effort should be made to fabricate testspecimens 64 6 3 mm (2.5 6 0.1 in.) in height. Heat theaggregate to the proper mixing temperature; then weigh therequired amount of bitumen at the proper temperature into theaggregate mixture. For mixes employing asphalt cement, thetemperature of the aggregat
22、e and asphalt at the time mixingbegins shall be in accordance with the following:Temperature Range, C (F)Grade min maxAC-2.5, AR1000, or 200300 Pen 99(210) 121(250)AC-5, AR2000, or 120150 Pen 110(230) 135(275)AC-10, AR4000, or 85100 Pen 121(250) 149(300)AC-20, AR8000, or 6070 Pen 132(270) 163(325)AC
23、-40, AR16000, or 4050 Pen 132(270) 163(325)Mixtures containing liquid asphalts do not require heat formixing. For tar mixtures, heat the aggregates and tar to thedesired temperatures, not to exceed 107C (225F). Mixing ofthe aggregate and bitumen shall be as thorough and rapid aspossible; mechanical
24、mixing is recommended.5.2.3 When mixing is completed, transfer the mix to asuitable flat pan approximately 279 by 178 by 25 mm (11 by 7by 1 in.) and cure this mixture for 2 to3hatatemperature of146 6 3C (2956 5F).FIG. 1 California Kneading CompactorFIG. 2 Face of Compactor RamD 1561 92 (2005)e12NOTE
25、 5Another procedure that has been used is to cure this mixturefor 15 to 18 h at a temperature of 60 6 3C (140 6 5F) in an ovenequipped with air circulation.NOTE 6Bituminous mixtures may also be prepared in accordancewith requirements of other test methods for which it is desired to use theCalifornia
26、 kneading compactor.5.3 Compaction of Specimens:5.3.1 TemperaturesUse one of the three following speci-fied temperatures when compacting the bituminous mixture.The mixtures and molds shall be brought to temperature priorto molding operations.5.3.1.1 60C (140F) for mixtures containing liquid-gradeasp
27、halts.5.3.1.2 110C (230F) for mixtures containing paving gradeasphalts.5.3.1.3 Room temperature for mixtures containing liquidgrade asphalts when it is desired to test with whatever moisturemay be present in the mixture.5.3.2 Molding SpecimensPlace the compaction mold inposition in the mold holder a
28、nd insert a paper disk, 101.6 mm(4 in.) in diameter, to cover the base plate of the mold holder.Place a steel shim under the edge of the mold temporarily inorder to have the base plate of the mold holder act as afree-fitting plunger during the compaction operation. Preheatthe round-nose rod. Weigh o
29、ut the required amount of bitumi-nous mixture for one specimen at the specified temperature andplace in the insulated feeder trough, which shall have beenpreheated approximately to the compaction temperature formixture. Spread the mixture uniformly on the feeder trough toensure uniformity when trans
30、ferring to the mold. By means ofa paddle of suitable dimensions to fit the cross section of thetrough, push one-half of the mixture into the mold. Rod theone-half portion of the mixture 20 times in the center of themass and 20 times around the edge by means of the round-noserod. Transfer the remaind
31、er of the sample to the mold andrepeat the rodding procedure. Place the mold and assembly intoposition on the California kneading compactor. By means ofthe variable transformer controlling the heater, maintain thecompactor foot sufficiently hot to prevent the mixture fromadhering to it. Apply approx
32、imately 20 tamping blows at apressure of 1.7 MPa (250 psi). The number of tamping blowswill vary, depending upon the type of the mixture, the purposebeing to form the mixture into a semi-compacted condition sothat it will not be unduly disturbed by the full pressure of 3.4MPa (500 psi). After semi-c
33、ompaction has been accomplished,remove the shim and release the mold-tightening screw suffi-ciently to allow approximately 3 mm (18 in.) side movement ofthe mold. Increase the compactor foot pressure to 3.4 MPa andapply 150 tamping blows to complete compaction in theCalifornia kneading compactor.NOT
34、E 7When testing referee samples for the purpose of qualifying acompactor, use only material for the test specimens which will compactunder the maximum foot pressure prescribed in 5.3.2 without visiblemovement, distortion, or penetration of the compactor foot.NOTE 8In some instances where sandy or un
35、stable material isinvolved, it may not be possible to accomplish the compaction in thekneading compactor because of undue movement of the mixture under thecompactor foot. In these instances use a 178-kN (40 000-lbf) static load(for a 101.6-mm (4-in.) diameter specimen) applied by the double plungerm
36、ethod in which a free-fitting plunger is placed on both the bottom andtop of the test specimen. Apply the load at the rate of 1.3 mm (0.05in.)/min and hold for 30 6 5s.5.3.3 Application of Static LoadAfter compaction in theCalifornia kneading compactor, place the mold and the speci-men in an oven at
37、 60C (140F) for the following periods oftime prior to applying the static leveling off load:If compacted at 60C (140F) 1 hIf compacted at 110C (230F) 1.5 h5.3.4 The “leveling off” load shall consist of the applicationof a static load of 56 kN (12 600 lbf) in a compression testingmachine. Use a testi
38、ng machine head or platen speed of 6 mm(0.25 in.)/min. Apply the load by the double plunger method inFIG. 3 Funnel, Feeder Trough, and Mold Assembly of the California Kneading CompactorD 1561 92 (2005)e13which metal followers are employed as free-fitting plungers onthe top and bottom of the specimen
39、. After releasing the“leveling off” load, measure the height of the specimen to thenearest 0.25 mm (0.01 in.), record the measurement, and placethe specimen, in the mold, in an oven in order to obtain thedesired temperature for testing.NOTE 9A push-out device for removing the specimen is described i
40、nTest Methods D 1560. The temperature of the specimen and the method oftransfer from the mold to the stabilometer are given in the procedure ofTest Methods D 1560.6. Report6.1 Report the following information:6.1.1 Specimen curing procedure,6.1.2 Height of the specimen, and6.1.3 Temperature of compa
41、ction in the California kneadingcompactor.7. Precision and Bias7.1 Since the procedure is used only for the preparation oftest specimens, no precision statement can be developed.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item men
42、tionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee
43、 and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meetin
44、g of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO
45、Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 1561 92 (2005)e14
