1、Designation: D 7405 08aStandard Test Method forMultiple Stress Creep and Recovery (MSCR) of AsphaltBinder Using a Dynamic Shear Rheometer1, 2This standard is issued under the fixed designation D 7405; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、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 the determination of percentrecovery and non-recoverable creep c
3、ompliance of asphaltbinders by means of Multiple Stress Creep and Recovery(MSCR) testing. The MSCR test is conducted using theDynamic Shear Rheometer (DSR) at a specified temperature.1.2 This standard is appropriate for unaged material, mate-rial aged in accordance with Test Method D 2872 (RTFO),mat
4、erial aged in accordance with Practice D 6521 (PAV), andmaterial aged in accordance with both Test Method D 2872 andPractice D 6521.NOTE 1The majority of development work on this test method wasperformed on material aged in accordance with Test Method D 2872(RTFO).1.3 The percent recovery is intende
5、d to provide a means todetermine the presence of elastic response and stress depen-dence of polymer modified and unmodified asphalt binders.1.4 A precision and bias statement for this standard has notbeen developed at this time. Therefore, this standard should notbe used for acceptance or rejection
6、of a material for purchasingpurposes.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the us
7、er 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:3C 670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsD8 Termino
8、logy Relating to Materials for Roads and Pave-mentsD 2872 Test Method for Effect of Heat andAir on a MovingFilm of Asphalt (Rolling Thin-Film Oven Test)D 5801 Test Method for Toughness and Tenacity of Bitu-minous MaterialsD 6084 Test Method for Elastic Recovery of BituminousMaterials by Ductilometer
9、D 6373 Specification for Performance Graded AsphaltBinderD 6521 Practice for Accelerated Aging of Asphalt BinderUsing a Pressurized Aging Vessel (PAV)D 7175 Test Method for Determining the Rheological Prop-erties of Asphalt Binder Using a Dynamic Shear Rheom-eter2.2 AASHTO Standards:4M 320 Specifica
10、tion for Performance-Graded AsphaltBinderTP 70 Test Method for Multiple Stress Creep and Recovery(MSCR) of Asphalt Binder Using a Dynamic ShearRheometer3. Terminology3.1 DefinitionsFor definitions of general terms used in thisstandard, refer to Terminology D8.3.1.1 creep and recovery, na standard rh
11、eological testprotocol whereby a specimen is subjected to a constant load fora fixed time period then allowed to recover at zero load for afixed time period.3.1.2 non-recoverable creep compliance (Jnr), nthe re-sidual strain in a specimen after a creep and recovery cycledivided by the stress applied
12、 in kPa.4. Summary of Test Method4.1 This test method is used to determine the presence ofelastic response in an asphalt binder under shear creep andrecovery at two stress levels at a specified temperature. For1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materi
13、als and is the direct responsibility of Subcommittee D04.44 onRheological Tests.Current edition approved July 1, 2008. Published July 2008. Originally approvedin 2008. Last previous edition approved in 2008 as D 7405 08.2This test method is based on a work product of the Federal HighwayAdministratio
14、n. A similar standard is published as AASHTO TP 70.3For 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.4Available
15、 from American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.performance grade
16、(PG) binders, the specified temperature willtypically be the PG grade upper temperature as determined inSpecification D 6373 or AASHTO M 320. Sample preparationand apparatus are in accordance with Test Method D 7175using the 25 mm parallel plate geometry with a 1-mm gapsetting. The sample is loaded
17、at constant stress for 1 s thenallowed to recover for 9 s. Ten creep and recovery cycles arerun at 0.100 kPa creep stress followed by ten at 3.200 kPacreep stress.5. Significance and Use5.1 This test method is used to identify the presence ofelastic response in a binder and the change in elastic res
18、ponseat two different stress levels. Non-recoverable creep compli-ance has been shown to be an indicator of the resistance of anasphalt binder to permanent deformation under repeated load.5.2 This test method is also useful as a surrogate for othertest methods used to measure elasticity in asphalt b
19、inders suchas Test Method D 5801 (Toughness and Tenacity), Test MethodD 6084 (Elastic Recovery), and Test Method D 7175 (DSRphase angle).6. Apparatus6.1 Dynamic Shear Rheometer (DSR)A dynamic shearrheometer as described in theApparatus section of Test MethodD 7175 and associated materials as describ
20、ed in the Materialssection of Test Method D 7175. The rheometer shall run instress control mode.7. Preparation of Test Specimen7.1 Prepare the test specimen in accordance with the Pre-paring Test Specimens section of Test Method D 7175.NOTE 2This test may be run on a specimen previously tested indyn
21、amic shear in accordance with the Test Procedure section of TestMethod D 7175.8. Procedure8.1 Allow the specimen to reach thermal equilibrium at thedesired test temperature in accordance with the Test Proceduresection of Test Method D 7175. If the specimen has previouslybeen tested in dynamic shear,
22、 allow the specimen to remainunloaded for at least one minute before starting the creep andrecovery test.8.2 Load the specimen at a constant creep stress of 0.100kPa for 1.00 second duration creep and follow with a zerostress recovery of 9.00 second duration. The commanded fulltorque for each creep
23、cycle shall be achieved within 0.003seconds from the start of the creep cycle as certified by theequipment manufacturer. Record the stress and strain at leastevery 0.10 seconds for the creep cycle and at least every 0.45seconds for the recovery cycle on a running accumulated timesuch that, in additi
24、on to other data points, data points at 1.00 sand 10.00 s for each cycles local time are explicitly recorded.8.2.1 If the DSR does not record the strain at exactly 1.00and 10.00 seconds then the DSR software shall extrapolateprior data to determine the strain value at the required time.Extrapolation
25、 data shall include a measured data point no morethan 0.05 s prior to the required time for a creep cycle, no morethan 0.30 s prior to the required time for a recovery cycle.NOTE 3If the creep and recovery curves will be used for modeling,more frequent data points may be required.8.3 Allowing no res
26、t period between cycles, repeat the creepand recovery cycle in 8.2 nine times for a total of ten cycles.8.4 Allowing no rest period following 8.3, repeat the tencreep and recovery cycles of 8.2 and 8.3 utilizing a load of3.200 kPa.NOTE 4The total time required to complete the two-step creep andrecov
27、ery test is 200 seconds.8.5 For each of the twenty creep and recovery cycles recordthe following:8.5.1 Initial strain value at the beginning of the creepportion of each cycle. This strain shall be denoted as 0.8.5.2 The strain value at the end of the creep portion (that is,after 1.0 s) of each cycle
28、. This strain shall be denoted as c.8.5.3 The adjusted strain value at the end of creep portion(that is, after 1.0 s) of each cycle:15c 0(1)8.5.4 The strain value at the end of the recovery portion(that is, after 10.0 s) of each cycle. This strain shall be denotedas r.8.5.5 The adjusted strain value
29、 at the end of recoveryportion (that is, after 10.0 s) of each cycle:105r 0(2)9. Calculation9.1 Using the results obtained in 8.5 determine the averagepercent recovery and non-recoverable creep compliance for theasphalt binder at creep stress levels of 0.100 kPa and 3.200 kPaas follows:9.1.1 For eac
30、h of the ten cycles at a creep stress of 0.100kPa calculate the percent recovery, r(100, N), for N =1to10:r100, N! 51 10! 1001(3)9.1.2 For each of the ten cycles at a creep stress of 3.200kPa calculate the percent recovery, r(3200, N), for N =1to10:r3200, N! 51 10! 1001(4)9.1.3 Calculate average per
31、cent recovery at 0.100 kPa:R100 5 SUMr100, N! / 10 for N 5 1to10 (5)9.1.4 Calculate average percent recovery at 3.200 kPa:R3200 5 SUMr3200, N! / 10 for N 5 1to10 (6)9.1.5 Calculate percent difference in recovery between0.100 kPa and 3.200 kPa:Rdiff5 R100 R3200! 100! / R100! (7)9.1.6 For each of the
32、ten cycles at a creep stress of 0.100kPa calculate the non-recoverable creep compliance, Jnr(100,N), for N =1to10:Jnr100, N! 510100(8)9.1.7 For each of the ten cycles at a creep stress of 3.200kPa calculate the non-recoverable creep compliance, Jnr(3200,N), for N =1to10:D 7405 08a2Jnr3200, N! 510320
33、0(9)9.1.8 Calculate average non-recoverable creep complianceat 0.100 kPa:Jnr100 5 SUMJnr100, N! / 10 for N 5 1 to 10 (10)9.1.9 Calculate average non-recoverable creep complianceat 3.200 kPa:Jnr3200 5 SUMJnr3200, N! / 10 for N 5 1to10 (11)9.1.10 Calculate percent difference in non-recoverable creepco
34、mpliance between 0.100 kPa and 3.200 kPa:Jnr2diff5 Jnr3200 Jnr100! 100! / Jnr3200! (12)10. Report10.1 Report the following information:10.1.1 Sample identification;10.1.2 Test temperature, to the nearest 0.1C;10.1.3 Average percent recovery at 0.100 kPa, R100, to thenearest 0.1 %;10.1.4 Average perc
35、ent recovery at 3.200 kPa, R3200, to thenearest 0.1 %;10.1.5 Percent difference between average recovery at 0.100kPa and 3.200 kPa, Rdiff, to the nearest 0.1 %;10.1.6 Non-recoverable creep compliance at 0.100 kPa,Jnr100, to three significant figures;10.1.7 Non-recoverable creep compliance at 3.200 k
36、Pa,Jnr3200, to three significant figures; and10.1.8 Percent difference between non-recoverable creepcompliance at 0.100 kPa and 3.200 kPa, Jnr-diff, to nearest0.1 %.11. Precision and Bias11.1 PrecisionThe within-laboratory repeatability andbetween-laboratory reproducibility of this test method arebe
37、ing determined according to Practice C 670 and will beavailable on or before June 2008. Therefore, this standardshould not be used for acceptance or rejection of material forpurchasing purposes.11.2 BiasThis test method has no bias because the valuesdetermined are defined only in terms of the test m
38、ethod.12. Keywords12.1 asphalt binder; creep and recovery; DSR; dynamicshear rheometer; elastic recovery; MSCR; non-recoverablecreep compliance; polymer modified asphaltASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin
39、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 and must
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41、esponsible 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 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 7405 08a3
