1、Designation: D7405 10Standard Test Method forMultiple Stress Creep and Recovery (MSCR) of AsphaltBinder Using a Dynamic Shear Rheometer1, 2This standard is issued under the fixed designation D7405; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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 comp
3、liance 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 D2872 (RTFO),materia
4、l aged in accordance with Practice D6521 (PAV), andmaterial aged in accordance with both Test Method D2872 andPractice D6521.NOTE 1The majority of development work on this test method wasperformed on material aged in accordance with Test Method D2872(RTFO).1.3 The percent recovery is intended to pro
5、vide 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 of a mat
6、erial 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 user of th
7、is 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:3C670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsD8 Terminology Rela
8、ting to Materials for Roads and Pave-mentsD2872 Test Method for Effect of Heat and Air on a MovingFilm of Asphalt (Rolling Thin-Film Oven Test)D5801 Test Method for Toughness and Tenacity of Bitumi-nous MaterialsD6084 Test Method for Elastic Recovery of BituminousMaterials by DuctilometerD6373 Speci
9、fication for Performance Graded AsphaltBinderD6521 Practice for Accelerated Aging of Asphalt BinderUsing a Pressurized Aging Vessel (PAV)D7175 Test Method for Determining the Rheological Prop-erties of Asphalt Binder Using a Dynamic Shear Rheom-eter2.2 AASHTO Standards:4M 320 Specification for Perfo
10、rmance-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 rheological test
11、protocol whereby a specimen is subjected to a constant load fora fixed time period then allowed to recover at zero load for afixed time period.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.44 onRheol
12、ogical Tests.Current edition approved Jan. 1, 2010. Published February 2010. Originallyapproved in 2008. Last previous edition approved in 2008 as D7405 08a. DOI:10.1520/D7405-10.2This test method is based on a work product of the Federal HighwayAdministration. A similar standard is published as AAS
13、HTO 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 from American Association of State Highw
14、ay 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.3.1.2 non-recoverable creep compliance (Jnr), nthe re-sidua
15、l strain in a specimen after a creep and recovery cycledivided by the stress applied 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. Forperfor
16、mance grade (PG) binders, the specified temperature willtypically be the PG grade upper temperature as determined inSpecification D6373 or AASHTO M 320. Sample preparationand apparatus are in accordance with Test Method D7175 usingthe 25 mm parallel plate geometry with a 1-mm gap setting.The sample
17、is loaded at constant stress for 1 s then allowed torecover for 9 s. Ten creep and recovery cycles are run at 0.100kPa creep stress followed by ten at 3.200 kPa creep stress.5. Significance and Use5.1 This test method is used to identify the presence ofelastic response in a binder and the change in
18、elastic responseat 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 i
19、n asphalt binders suchas Test Method D5801 (Toughness and Tenacity), Test MethodD6084 (Elastic Recovery), and Test Method D7175 (DSRphase angle).6. Apparatus6.1 Dynamic Shear Rheometer (DSR)A dynamic shearrheometer as described in theApparatus section of Test MethodD7175 and associated materials as
20、described in the Materialssection of Test Method D7175. 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 D7175.NOTE 2This test may be run on a specimen previously tested
21、indynamic shear in accordance with the Test Procedure section of TestMethod D7175.8. Procedure8.1 Allow the specimen to reach thermal equilibrium at thedesired test temperature in accordance with the Test Proceduresection of Test Method D7175. If the specimen has previouslybeen tested in dynamic she
22、ar, 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 cre
23、ep 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 add
24、ition 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.Extrapolat
25、ion 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
26、rest 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 andre
27、covery 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 cy
28、cle. 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 va
29、lue 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
30、each 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
31、percent 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)D7405 1029.1.6 For
32、each of the 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:Jnr3200, N! 51032
33、00(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 creepc
34、ompliance between 0.100 kPa and 3.200 kPa:Jnr2diff5 Jnr3200 Jnr100! 100! / Jnr100! (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 C670 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 me
38、thod.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 t
39、his 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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42、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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D7405 103
