1、Designation:D 3496 99Standard Practice forPreparation of Bituminous Mixture Specimens for DynamicModulus Testing1This standard is issued under the fixed designation D 3496;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of l
2、ast revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the preparation of cylindrical speci-mens of bituminous paving mixture suitable for dynamicmodulus tes
3、ts.The practice is intended for dense-gradedbituminous concrete mixtures containing aggregate up to25.0-mm maximum size.1.2 The values stated in SI units are the standard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of
4、 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 1560 Test Methods for Resistance to Deformation andCohesion of Bituminous Mixtures by Means of HveemAppa
5、ratus2D 1561 Practice for Preparation of Bituminous Mixture TestSpecimens by Means of California Kneading Compactor2D 3387 Test Method for Compaction and Shear Propertiesof Bituminous Mixtures by Means of the U.S.Corps ofEngineers Gyratory Testing Machine(GTM)23.Apparatus3.1 California Kneading Comp
6、actorWhen the Californiakneading compactor is used to prepare specimens,the appara-tus shall be in accordance with Practice D 1561,except steelmolding cylinders with 6-mm wall thickness having an insidediameter of 100 mm and height of 250 mm shall be used.3.2 Corps of Engineers Gyratory Testing Mach
7、ineWhenthe Corps of Engineers gyratory testing machine is used toprepare specimens,the apparatus shall be as specified by TestMethod D 3387,except that only those models capable ofproducing 100-mm diameter by 200-mm high specimens areapplicable.The dimensions of the molding cylinders for thismachine
8、 shall be 100 mm in diameter by 300-mm long.4.Test Specimens4.1 Preparation of MixturePrepare approximately 4000 gof the bituminous mixture in accordance with Test MethodsD 1560 or Test Method D 3387 to produce specimens 100 mmin diameter by 200 mm in height.4.2 Size of SpecimensThe cylindrical spec
9、imens shall be100 mm in diameter by 200 mm in height.5.Procedure5.1 Compaction TemperatureThe compaction tempera-ture for bituminous mixtures shall be in accordance withPractice D 1561 or Test Method D 3387,depending on whichset of equipment is used.5.2 Molding SpecimensHeat the compaction molds to
10、thetemperatures specified in 5.1.5.2.1 Specimens prepared using the California kneadingcompactor shall be prepared using the following procedure formolding specimens.Place the compaction mold in position inthe mold holder and insert a paper disk 100 mm in diameter tocover the base plate of the mold
11、holder.Weigh out one half ofthe required amount of bituminous mixture for one specimen atthe specified temperature and place uniformly in the insulatedfeeder trough,which has been preheated to the compactiontemperature for the mixture.By means of the variable trans-former controlling the heater,main
12、tain the compactor footsufficiently hot to prevent the mixture from adhering to it.Bymeans of a paddle of suitable dimensions to fit the cross sectionof the trough,push 30 approximately equal portions of themixture continuously and uniformly into the mold while 30tamping blows at a pressure of 1.7 M
13、Pa are applied.Immedi-ately place the remaining one half of the mixture uniformly inthe feeder trough.Push 30 approximately equal portions of themixture continuously and uniformly into the mold while 30tamping blows at pressure of 1.7 MPa are applied(Note 1).NOTE1If sandy or unstable material is inv
14、olved and there is unduemovement of the mixture under the compactor foot,reduce compactiontemperature and compactor foot pressure until kneading compaction canbe accomplished.5.2.1.1 Application of Static LoadImmediately after com-paction in the California kneading compactor,apply a staticload to th
15、e specimen using a compression testing machine.Apply the load by the double-plunger method in which metalfollowers are used as free-fitting plungers on top and bottom of1This test method is under the jurisdiction of ASTM Committee D-4 on Roadand Paving Materials and is the direct responsibility of S
16、ubcommittee D04.26 onFundamental/Mechanistic Tests.Current edition approved Aug.10,1999.Published September 1999.Originallypublished as D 3496 76 T.Last previous edition D 3496 93.2Annual Book of ASTM Standards,Vol 04.03.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.the specimen.Apply the load on the specimen at a rate of 1.27mm/min until an applied pressure of 6.9 MPa is reached.Release the load immediately.After the compacted specimenhas cooled sufficientl
