ASTM_D_7369_-_11.pdf

Designation:D736911Standard Test Method forDetermining the Resilient Modulus of Bituminous Mixturesby Indirect Tension Test1This standard is issued under the fixed designation D7369;the number immediately following the designation indicates the year oforiginal adoption or,in the 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.1.Scope1.1 This test method covers procedures for preparing andtesting laboratory-fabricated or field-recovered cores of bitu-minous mixtures to determine resilient modulus values using arepeated-load indirect tension test.1.2 The values stated in SI units are regarded as thestandard.Values in parentheses are for informational use.1.3 A precision and bias statement for this standard has notbeen developed at this time.Therefore,this standard should notbe used for acceptance or rejection of a material for purchasingpurposes.1.4 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D3387 Test Method for Compaction and Shear Properties ofBituminous Mixtures by Means of the U.S.Corps ofEngineers Gyratory Testing Machine(GTM)D3666 Specification for Minimum Requirements for Agen-cies Testing and Inspecting Road and Paving MaterialsD4013 Practice for Preparation of Test Specimens of Bitu-minous Mixtures by Means of Gyratory Shear Compactor(Withdrawn 2013)3D6925 Test Method for Preparation and Determination ofthe Relative Density of Asphalt Mix Specimens by Meansof the Superpave Gyratory CompactorD6926 Practice for Preparation of Bituminous SpecimensUsing Marshall ApparatusD6931 Test Method for Indirect Tensile(IDT)Strength ofBituminous Mixtures2.2 Other Document:NCHRP Project 1-28A,Research Results Digest Number285Laboratory Determination of Resilient Modulus forFlexible Pavement Design,January 20043.Terminology3.1 Definitions:3.1.1 contact load(Pcontact),nthe vertical load placed onthe specimen to maintain a positive contact between theloading strip and the specimen.The contact load is 4%of themaximum load(0.04 Pmax)and is not less than 22.2 N(5 lb),but not more than 89.0 N(20 lb).3.1.2 core,nan intact cylindrical specimen of pavementmaterial,which is removed from the pavement by drilling andsampling at the designated location.A core may consist of,orinclude,one,two,or more than two different layers.3.1.3 cyclic load(resilient vertical load,Pcyclic),nloadapplied to a specimen,which is directly used to calculateresilient modulus.Pcyclic5 Pmax2 Pcontact(1)3.1.4 haversine-shaped load form,nthe required loadpulse for the resilient modulus test.The load pulse is in theform(1-cos)/2 with the cyclic load varying from the contactload(Pcontact)to the maximum load(Pmax).3.1.5 instantaneous resilient modulus,ndetermined fromthe deformation-time plots(both horizontal and vertical)asdescribed in Section 10.3.1.6 lift,nthat part of the pavement produced withsimilar material and placed with similar equipment and tech-niques.The lift thickness is the thickness of the compactedbituminous mixture that is achieved with one pass of thelaydown machine and the subsequent compaction process andcan be equal to or less than the core thickness or length.3.1.7 maximum applied load(Pmax),nthe maximum totalload applied to the sample,including the contact and cyclic(resilient)loads.Pmax5 Pcontact1Pcyclic(2)1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.26 onFundamental/Mechanistic Tests.Current edition approved Dec.1,2011.Published January 2012.Originallypublished 2009 as D736909.DOI:10.1520/D7369-11.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.8 test specimen,nthat part of the layer which is usedfor,or in,the specified test.The thickness of the test specimencan be equal to or less than the layer thickness.3.1.9 totaldeformation,ndeterminedfromthedeformation-time plots(both horizontal and vertical)as de-scribed in Section 10.4.Summary of Test Method4.1 The repeated-load indirect tension resilient modulus testof bituminous mixtures is conducted through repetitive appli-cations of compressive loads in a haversine waveform.Thecompressive load is applied along a vertical diametral plane ofa cylindrical specimen of asphalt concrete.The resultin