1、Designation: D7175 15Standard Test Method forDetermining the Rheological Properties of Asphalt BinderUsing a Dynamic Shear Rheometer1This standard is issued under the fixed designation D7175; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, 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 the determination of the dy-namic shear modulus and phase angle of asphal
3、t binders whentested in dynamic (oscillatory) shear using parallel plategeometry. It is applicable to asphalt binders having dynamicshear modulus values in the range from 100 Pa to 10 MPa. Thisrange in modulus is typically obtained between 4 and 88C at10 rad/s. This test method is intended for deter
4、mining the linearviscoelastic properties of asphalt binders as required forspecification testing and is not intended as a comprehensiveprocedure for the full characterization of the viscoelasticproperties of asphalt binders.1.2 This standard is appropriate for unaged materials, ma-terial aged in acc
5、ordance with Test Method D2872, materialaged in accordance with Practice D6521, or material aged inaccordance with both Test Method D2872 and Practice D6521.This procedure is limited to asphalt binders that containparticles with largest dimension less than 250 m.1.3 The values stated in SI units are
6、 to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard may involve hazardous materials,operations, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the use
7、r of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsD140 Practice
8、for Sampling Bituminous MaterialsD2170 Test Method for Kinematic Viscosity of Asphalts(Bitumens)D2171 Test Method for Viscosity of Asphalts by VacuumCapillary ViscometerD2872 Test Method for Effect of Heat and Air on a MovingFilm of Asphalt (Rolling Thin-Film Oven Test)D6373 Specification for Perfor
9、mance Graded AsphaltBinderD6521 Practice for Accelerated Aging of Asphalt BinderUsing a Pressurized Aging Vessel (PAV)E77 Test Method for Inspection and Verification of Ther-mometersE563 Practice for Preparation and Use of an Ice-Point Bathas a Reference TemperatureE644 Test Methods for Testing Indu
10、strial Resistance Ther-mometersE882 Guide for Accountability and Quality Control in theChemical Analysis Laboratory2.2 AASHTO Standards:3M320 Standard Specification for Performance-Graded As-phalt BinderR29 Practice for Grading or Verifying the PerformanceGrade of an Asphalt BinderT315 Standard Test
11、 Method for Determining the Rheologi-cal Properties of Asphalt Binder Using a Dynamic ShearRheometer2.3 Deutsche Industrie Norm (DIN) Standard:443760 Standard for Calibration of Thermocouples3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 annealing, nthe process of removing th
12、e effects ofsteric hardening by heating the binder until it is sufficientlyfluid so that it can be easily poured.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.44 onRheological Tests.Current edition a
13、pproved July 1, 2015. Published August 2015. Originallyapproved in 2005. Last previous edition approved in 2008 as D7175 08. DOI:10.1520/D7175-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
14、 volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.4Available from Beuth Verlag GmbH (DIN
15、- DIN Deutsches Institut furNormung e.V.), Burggrafenstrasse 6, 10787, Berlin, Germany, http:/www.en.din.de.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.2 asphalt binder, nan asphalt-based cement that isproduced from petroleum
16、residue either with or without theaddition of non-particulate modifiers.3.1.3 complex shear modulus (G*), nratio calculated bydividing the absolute value of the peak-to-peak shear stress, ,by the absolute value of the peak-to-peak shear strain, .3.1.4 dummy test specimen, na specimen formed betweent
17、he DSR test plates from asphalt binder or other polymer forthe purpose of determining the temperature in the asphaltbinder between the plates.3.1.4.1 DiscussionThe dummy test specimen is not usedto measure the rheological properties of asphalt binder but isused solely to determine temperature correc
18、tions.3.1.5 linear viscoelastic, adjwithin context of this testmethod, refers to a region of behavior in which the dynamicshear modulus is independent of shear stress or strain.3.1.6 steric hardening, nrefers to time-dependent associa-tions that occur between asphalt binder molecules duringstorage a
19、t ambient temperature. The effect of molecular asso-ciation or steric hardening on the dynamic shear modulus isasphalt specific and may be apparent even after a few hours ofstorage.3.1.7 oscillatory shear, nrefers to a type of loading inwhich a shear stress or shear strain is applied to a test sampl
20、ein an oscillatory manner such that the shear stress or strainvaries in amplitude about zero in a sinusoidal manner.3.1.8 parallel plate geometry, nrefers to a testing geom-etry in which the test specimen is sandwiched between tworigid parallel plates and subjected to shear.3.1.9 phase angle (), nth
21、e angle in degrees between asinusoidally applied strain and the resultant sinusoidal stress ina controlled-strain testing mode, or between the applied stressand the resultant strain in a controlled-stress testing mode.3.1.10 portable temperature measuring device, nrefers toan electronic device that
22、is separate from the dynamic shearrheometer and that consists of a detector (probe containing athermocouple or resistive element), associated electroniccircuitry, and readout system.3.1.11 reference temperature measuring device, nrefers toa NIST-traceable liquid-in-glass or electronic thermometer th
23、atis used as a laboratory standard.3.1.12 thermal equilibrium, ncondition where the tem-perature of the test specimen mounted between the test platesis constant with time.4. Summary of Test Method4.1 This standard contains the procedure used to measurethe complex shear modulus (G*) and phase angle (
24、) of asphaltbinders using dynamic shear rheometer and parallel plategeometry.4.2 The standard is suitable for use when the dynamic shearmodulus varies between 100 Pa and 10 MPa. This range inmodulus is typically obtained between 4 and 88C, dependingupon the grade, test temperature, and conditioning
25、(aging) ofthe asphalt binder.4.3 Test specimens, nominally 25 mm in diameter by 1 mmthick or 8 mm in diameter by 2 mm thick, are formed betweenparallel metal plates.4.4 During testing, one of the parallel plates is oscillatedwith respect to the other at pre-selected frequencies andangular deflection
26、 (or torque) amplitudes. The required ampli-tude depends upon the value of the complex shear modulus ofthe asphalt binder being tested. The required amplitudes havebeen selected so that, for most asphalt binders, the testingspecified in this standard is within the region of linear behavior.4.5 The t
27、est specimen is maintained at the test temperature6 0.1C by enclosing the upper and lower plates in a thermallycontrolled environment or test chamber.4.6 Oscillatory loading frequencies using this standard canrange from 1 to 160 rad/s. Specification testing is performed ata test frequency of 10 rad/
28、s. The complex modulus (G*) andphase angle () are calculated automatically as part of theoperation of the rheometer using proprietary computer soft-ware supplied by the instrument manufacturer.5. Significance and Use5.1 The test temperature for this test is related to thetemperature experienced by t
29、he pavement in the geographicalarea for which the asphalt binder is intended to be used.5.2 The complex shear modulus is an indicator of thestiffness or resistance of asphalt binder to deformation underload. The complex shear modulus and the phase angle definethe resistance to shear deformation of t
30、he asphalt binder in thelinear viscoelastic region. The complex modulus and the phaseangle are used to calculate performance-related criteria inaccordance with Specification D6373 or AASHTO StandardM320.6. Interferences6.1 Particulate material in the asphalt binder is limited toparticles with longes
31、t dimensions less than 250 m. Particleswith dimensions greater than 250 m approach the dimensionsof the gap (1000 m). In order to accurately characterize atwo-phase material containing particulate material it is wellaccepted that the thickness of the test specimen must be at leastfour times the maxi
32、mum particle size.6.1.1 The calculation of the complex modulus from the dataobtained from the DSR is highly dependent upon an accuratemeasurement of the diameter of the test specimen. In theprocedure, the diameter of the test specimen is assumed equalto the diameter of the test plates. This assumpti
33、on is valid onlyif the test sample is properly trimmed.6.1.2 The physical properties of asphalt binders are verysensitive to test temperature and thermal history. Thermalhistory is the number of times asphalt binder sample has beenheated prior to testing. Controlling the test temperature to6 0.1C an
34、d limiting the number of times the asphalt sample isheated prior to testing (only one heating is recommended) isessential in order to obtain repeatable test results within alaboratory as well as to reproduce results between laboratories.D7175 1527. Apparatus7.1 Dynamic Shear Rheometer (DSR) Test Sys
35、temA dy-namic shear rheometer test system consisting of parallel metalplates, a means for controlling the temperature of the testspecimen, a loading device, and a control and data acquisitionsystem. The manufacturer of the device shall provide acertificate certifying that the frequency, deflection a
36、ngle, andtorque are controlled, measured, or both, with accuracy of 1 %or less in the range of this measurement.7.1.1 Test PlatesMetal plates cylindrical in shape, formedfrom steel or aluminum, with smooth ground surfaces arerequired. Two plates 8.00 6 0.02 mm in diameter and twoplates 25.00 6 0.05
37、mm in diameter are required. The testplates shall have a minimum thickness or raised portion of 1.5mm to allow sufficient clearance for trimming the specimen.The plates shall be formed as an integral part of the test fixturesthat are used to mount the plates in the DSR as shown in Fig.1.NOTE 1The up
38、per and lower plates should be concentric with eachother.At the present there is no suitable procedure for the user to check theconcentricity except to visually observe whether or not the upper andlower plates are centered with respect to each other. The moveable plateshould rotate without any obser
39、vable horizontal or vertical wobble. Thismay be checked visually or with a dial gage held in contact with the edgeof the moveable plate while it is being rotated.7.1.2 Environmental ChamberA chamber for controllingthe temperature of the test specimen. The medium for heatingand cooling the specimen i
40、n the environmental chamber shallnot affect asphalt binder properties. The temperature in thechamber may be controlled by the circulation of fluidconditioned gas, nitrogen or water is acceptableor by asuitable arrangement of actively temperature controlled heatingelements (for example, solid state P
41、eltier elements) surround-ing the sample. When laboratory air is used in a forced airoven, a suitable dryer must be included to prevent condensa-tion of moisture on the test plates. The environmental chamberand the temperature controller shall control the temperature ofthe test specimen mounted betw
42、een the test plates, includingany thermal gradients within the test specimen, at the testtemperature 60.1C. The chamber or the water in the chambershall completely enclose the top and the bottom plates tominimize thermal gradients within the fixtures and test speci-men.NOTE 2A circulating bath unit,
43、 separate from the DSR that pumps thewater through the test chamber may be required if a fluid medium is used.7.1.2.1 Temperature ControllerA temperature controllercapable of maintaining the temperature of the test specimen atthe test temperature for the entire range of test temperatures.7.1.3 Inter
44、nal DSR Temperature Measurement DeviceAplatinum resistance temperature measurement device (PRT)mounted within the environmental chamber as an integral partof the DSR and in close proximity to the fixed plate, with arange of 4 to 88C, and with a resolution of 0.1C. Thistemperature measurement device
45、shall be used to control thetemperature of the test specimen between the plates and shallprovide a continuous readout of temperature during themounting, conditioning, and testing of the specimen.7.1.4 Loading DeviceThe loading device shall be capableof applying a sinusoidal oscillatory load to the s
46、pecimen at afrequency of 10.0 6 0.1 rad/s. If frequencies other than 10rad/s are used, the frequency shall be accurate to 1 %. Theloading device shall be capable of providing either a stresscontrolled or strain controlled load within a range of stress orstrain necessary to make the measurements desc
47、ribed in thistest method.7.1.5 Data Acquisition SystemThe data acquisition systemshall provide a record of temperature, frequency, deflectionangle, and torque. The manufacturer of the rheometer shallprovide a certificate certifying that the frequency, deflectionangle, and torque are reported with an
48、 accuracy of at least 1 %.7.2 Specimen Mold (optional)The overall dimensions ofthe silicone rubber mold for forming asphalt binder testspecimens may vary but the overall thickness shall be at least5 mm thick.NOTE 3The following dimensions have been found suitable: For a25-mm test plate with a 1-mm g
49、ap a mold cavity with a concave bottomwith an approximate diameter of 18 mm and a depth of at least 2.0 mmand for an 8-mm test plate with a 2-mm gap a mold cavity with a concavebottom with an approximate diameter of 8 mm and a depth of at least 2.5mm.7.3 Trimming ToolA tool suitable for trimming excessbinder from the periphery of the test specimen to produce asmooth face on the test specimen that is parallel and coincidentwith the outer diameter of the upper and lower plates.7.4 Reference Temperature Measurement DeviceEither aNIST-trace
