1、Designation: D7643 16Standard Practice forDetermining the Continuous Grading Temperatures andContinuous Grades for PG Graded Asphalt Binders1This standard is issued under the fixed designation D7643; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase 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 practice is used to estimate the continuous gradingtemperatures and continuous grade
3、 for an asphalt binder gradedin accordance with the requirements specified in SpecificationD6373.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any
4、, 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:2D8 Terminology Relating to Materials for Roads and
5、Pave-mentsD2872 Test Method for Effect of Heat and Air on a MovingFilm of Asphalt (Rolling Thin-Film Oven Test)D6373 Specification for Performance Graded AsphaltBinderD6521 Practice for Accelerated Aging of Asphalt BinderUsing a Pressurized Aging Vessel (PAV)D6648 Test Method for Determining the Fle
6、xural CreepStiffness of Asphalt Binder Using the Bending BeamRheometer (BBR)D6723 Test Method for Determining the Fracture Propertiesof Asphalt Binder in Direct Tension (DT)D6816 Practice for Determining Low-Temperature Perfor-mance Grade (PG) of Asphalt BindersD7175 Test Method for Determining the
7、Rheological Prop-erties of Asphalt Binder Using a Dynamic Shear Rheom-eter3. Terminology3.1 Definitions: Definitions for many terms common toasphalt cement and asphalt binder are found in TerminologyD8.3.2 Definitions of Terms Specific to This Standard:3.2.1 continuous grade, na grade defined by the
8、 estimatedupper and lower continuous grading temperatures.3.2.2 continuous grading temperatures, Tc,nthe estimatedtemperatures at which the properties of an asphalt binder areequal to the specification requirements given in Tables 1 or 2 ofSpecification D6373.3.2.3 difference between estimated conti
9、nuous grading tem-perature for S and the m-value, TCdetermined by subtract-ing the continuous grading temperature for the m-value fromthe continuous grading temperature for S.3.2.4 PG grading temperatures, TPG,nthe temperatureslisted in Specification D6373 used to designate the grade of aPG binder,
10、for example, 64 C, 22 C, and 28 C for a PG64-28.3.2.5 specification requirements, nthe limiting valuesgiven in Specification D6373 that are used to grade an asphaltbinder, for example, 1.00 kPa for G*/sin, 300 MPa for S, etc.3.2.6 test temperatures, T1and T2,ntwo PG gradingtemperatures, one grade ap
11、art such that the measured proper-ties at the two temperatures bracket the specification require-ment for the property in question.4. Summary of Practice4.1 The continuous grading temperature for each specifica-tion requirement is determined by interpolating between testresults obtained at two adjac
12、ent specification temperatures. Thetwo temperatures are chosen so that the test result at onetemperature is greater than the specification requirement andthe test result at the other temperature is less than thespecification requirement. The upper continuous grade isdetermined as the lower of the tw
13、o continuous grading tem-peratures determined for the original and RTFOT condition1This practice is under the jurisdiction of ASTM Committee D04 on Road andPaving Materials and is the direct responsibility of Subcommittee D04.44 onRheological Tests.Current edition approved Dec. 1, 2016. Published Ja
14、nuary 2017. Originallyapproved in 2010. Last previous edition approved in 2010 as D7643 10. DOI:10.1520/D7643-16.2For 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
15、 standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in th
16、e Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1(Test Methods D2872 and D7175). The intermediate continu-ous grade is equal to the intermediate continuous gradingtem
17、perature (Practice D6521, Test Method D7175). The lowercontinuous grade is determined as the higher of the continuousgrading temperatures for S and the m-value (Practice D6521,Test Method D6648).5. Significance and Use5.1 The continuous grading temperatures and continuousgrade are used for informati
18、onal purposes only and shall not beused for the sale or purchase of asphalt binders. The continuousgrading temperatures and continuous grade may be used forforensic or research studies and when producing, blending,modifying, or otherwise evaluating asphalt binders. This guideis applicable to Specifi
19、cation D6373, Tables 1 and 2.6. Procedure6.1 Conduct tests as described below.6.1.1 Testing When Continuous Grading Criteria Do NotInclude Failure Strain (Table 1)For each of the specificationproperties (for example, G*/sin, S, m-value, etc.) for which acontinuous grading temperature is to be determ
20、ined, obtain testresults at two test temperatures, T1and T2as described in 3.2.6.When the intermediate grading temperature is required, thedifference between T1and T2shall be 3 C.NOTE 1For example, a PG 64-XX tested for G*/sin at 64 C and70 C may give test results of 1.86 and 0.89 kPa, respectively.
21、 Theseresults bracket the specification requirement 1.00 kPa.6.1.2 Testing When Continuous Grading Criteria IncludeFailure Strain (Table 1)For the low temperature, obtain testresults for S and the m-value (as described in 6.1.1) anddetermine the strain at failure at two test temperatures, T1andT2, s
22、uch that test results bracket 1 %.NOTE 2Additional testing may be required to verify that S is between300 and 600 MPa at the low temperature PG grade.6.1.3 Testing When Using Table 2For the lowtemperature, only perform the testing needed to determine thecritical cracking temperature.6.2 Perform Inte
23、rpolation to Determine Continuous Grad-ing TemperaturesFor each pair of test results obtained as per6.1, interpolate between T1and T2to determine the temperatureat which the test results would equal the respective specifica-tion requirement. The interpolated temperatures shall be re-ported as the co
24、ntinuous grading temperatures.6.2.1 For the upper and intermediate continuous gradingtemperatures the interpolation shall be on a semi-logarithmicscale using the following equation:TC5 T11$log10PS! 2 log10P1!%$T22 T1% $log10P2!2 log10P1!% (1)where:TC= continuous grading temperature for the specifica
25、-tion requirement in question, C,T1,T2= test temperatures, C,PS= specification requirement for property in question,andP1,P2= test result for the specification property in questionat T1and T2, respectively.6.2.2 For the lower continuous grading temperature theinterpolation for S shall be on a semi-l
26、ogarithmic scale usingthe following equation:TC5 T11$log10PS! 2 log10P1!%$T22 T1% $log10P2!2 log10P1!% 2 10 C (2)NOTE 3For calculation purposes, T1may be designated as the upperor lower temperature as long as the corresponding test result is used for P1.When using these equations retain the negative
27、 signs for temperaturesbelow 0 C.NOTE 4Because the properties are a non-linear function of tempera-ture adjacent grading temperatures should always be used in Eq 1 or Eq2. Otherwise the interpolation will give differing results.NOTE 5The TREND function in Excel performs linear regression andcan be u
28、sed to solve Eq 1 and 2. However, when using the TRENDfunction, arithmetic values of T1and T2must be used for the Ys andlogarithmic values of P1, P2, and PSmust be used for the Xs. Thearithmetic value of the properties and specification requirement are usedin the TREND function when calculating the
29、continuous grading tempera-ture for the m-value and failure strain.6.2.3 For the lower continuous grading temperature, theinterpolation for the m-value shall be on an arithmetic scaleusing the following equation:TC5 T11$PS2 P1%$T22 T1% $P22 P1% 2 10 C (3)6.3 Determine continuous grade and TCas descr
30、ibedbelow.6.3.1 Continuous Grade When the Criteria Do Not IncludeFailure Strain (Table 1)Determine the continuous gradebased on the upper and lower continuous grading temperaturesusing the same rationale as presented in Specification D6373.The lower of the two upper continuous grading temperatures(f
31、or G*/sin, original, and RTFO) shall determine the hightemperature for the PG grade. The upper of the two continuousgrading temperatures (for S and the m-value) shall determinethe low temperature for the PG grade.6.3.2 Continuous Grade When the Criteria Include FailureStrain, Table 1The upper of the
32、 two continuous gradingtemperatures for the m-value and the failure strain at 1% shalldetermine the low temperature for the PG grade with therequirement that S must be between 300 and 600 MPa.6.3.3 Table 2The low temperature for the PG grade isequal to the thermal cracking temperature, TCR, as deter
33、minedby using Test Method D6723 and Practice D6816.6.3.4 TCCalculate TCas the continuous grading tem-perature for S minus the continuous grading temperature forthe m-value.NOTE 6TCis positive if the continuous grading temperature for S isabove the continuous grading temperature for the m-value and n
34、egative ifthe continuous grading temperature for the m-value is above the continu-ous grading temperature for S.7. Report7.1 Continuous Grading TemperaturesReport the upperand lower continuous grading temperatures to the nearest0.1 C, and when required also report the intermediate con-tinuous gradin
35、g temperatures to the nearest 0.1 C.D7643 1627.2 Continuous GradeReport the continuous grade to thenearest 0.1 C using the procedure described in 6.3, forexample, PG 61.9-22.6.7.2.1 Intermediate Continuous GradeWhen required, re-port the intermediate continuous grading temperature as asuffix to the
36、continuous grade, for example, PG 61.9-22.6(19.3).7.3 TCWhen required, report TCto the nearest 0.1 C.7.4 Grading Criteria UsedReport the use of Table 1failure strain or Table 2, if used.8. Keywords8.1 continuous grade; continuous grading temperature; per-formance graded binders (PG Grade)APPENDIX(No
37、nmandatory Information)X1. SAMPLE PROBLEMS AND COMMENTARYX1.1 Table X1.1, Column 1Data necessary to verify theSpecification D6373 Table 1 PG grade for sample A are givenin column 1. Passing test results are shown for each specifica-tion requirement. A single test result for each specificationrequire
38、ment is sufficient to verify a PG grade. Note that the testresults that satisfy the specification requirement are underlinedin Table X1.1. The symbol X indicates that there is insuffi-cient information to complete the required calculation, eitherdue to a data error or insufficient information.X1.2 T
39、able X1.1, Column 2The additional data requiredto determine the continuous grading temperatures for SampleAhave been added to column 2. In order to determine thecontinuous grading temperature, passing and failing test resultsare needed for each specification requirement. For each speci-fication requ
40、irement, the continuous grading temperature isthen calculated using Eq 1 or Eq 2. The lower of the twocontinuous grading temperatures (87.2 C versus 87.6 C)determines the upper continuous grade and the upper of the twoTABLE X1.1 Sample Problems with Commentary: D6373 Table 1NOTE 1X = Insufficient in
41、formation to make determination.CommentsColumn 1Asphalt BinderAGrading OnlyColumn 2Asphalt BinderAwith TCColumn 3Asphalt BinderBColumn 4Asphalt BinderCPG Grade:AContinuous Grade:TC, C:82-28(31)X-X(X)X82-28(31)87.2-32.8-29.3+0.476-34(25)X-35.4-26.84.1X-28(X)X-32.9(X)+0.7UpperOriginal:G*/sin $ 1.00T1,
42、CG*/sin at T1, kPaT2,CG*/sin at T2, kPa821.83880.91821.83880.91761.98820.98761.49820.82Highest Passing Temperature, CContinuous Grading Temperature, C8287.28287.27681.87680.0UpperRTFOT:G*/sin $ 2.20Test Temp. T1,CG*/sin at T1, kPaTest Temp.T2,CG*/sin at T2, kPa824.21824.21882.10822.30762.31824.29Hig
43、hest Passing Temperature, CContinuous Grading Temperature, C82 8287.682XXXIntermediatePAV:G*/sin # 5000Test Temp. T1,CG*/sin at T1, kPaTest Temp.T2,CG*/sin at T1, MPa283920313920286020283850257610282490257120Lowest Passing Temperature, CContinuous Grading Temperature, C28 3129.32826.828XLowerPAV:S(6
44、0) # 300Test Temp. T1,CS(60) at T1, MPaTest Temp.T2,CS(60) at T1, MPa18163181632435024153303211814724350Lowest Passing Temperature, CContinuous Grading Temperature, C28 2832.83439.51832.9LowerPAV:m(60) $ 0.300Test Temp. T1,Cm-value at T1Test Temp.T2,Cm-value at T2180.363180.363240.290240.303340.2781
45、80.331240.298Lowest Passing Temperature, CContinuous Grading Temperature, C28 2833.23435.42833.6AIntermediate PG Grade calculated from test results as (4 C + average of upper and lower grading temperatures).D7643 163lower continuous grading temperatures (32.8 C versus 33.2C) determines the lower con
46、tinuous grade. For the interme-diate grading temperature, the continuous grade is equal to thecontinuous grading temperature (26.3 C).X1.3 Table X1.1, Column 3In column 3 the continuousgrading temperature for the original binder is in one gradeinterval (between 76 C and 82 C) below the interval for
47、theRTFOT (between 82 C and 88 C). The continuous gradingtemperature for the original controls the continuous grade anda second (failing) test result for the RTFOT condition is notneeded. However, the 82 C test result is needed to determinethe continuous grading temperature for the RTFOT conditionand
48、 the continuous upper grade. A similar situation can occurat the lower temperature if the continuous grading temperaturefor S and the m-value fall in different grading temperatureintervals.X1.4 Table X1.1, Column 4Several data errors that pre-vent the correct calculation of either the continuous gra
49、dingtemperature or the continuous grade are illustrated in column 4.The test results for the RTFOT residue do not bracket thespecification requirement. Therefore the continuous gradingtemperature cannot be determined and as a consequence theupper continuous grade cannot be determined. The test resultsfor the intermediate temperature were obtained at a 6-Cinterval whereas 3-C interval is required for the intermediatetemperature. The co
