ASTM D2940 D2940M-2009 Standard Specification for Graded Aggregate Material For Bases or Subbases for Highways or Airports《公路或机场底层或次底层用分级集料材料的标准规范》.pdf

1、Designation: D 2940/D 2940M 09Standard Specification forGraded Aggregate Material For Bases or Subbases forHighways or Airports1This standard is issued under the fixed designation D 2940/D 2940M; the number immediately following the designation indicates theyear of original adoption or, in the case

2、of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specifi

3、cation covers quality-controlled graded ag-gregates that, when hauled to and properly spread and com-pacted on a prepared grade to appropriate density standards,may be expected to provide adequate stability and load supportfor use as highway or airport bases or subbases.NOTE 1The engineer is caution

4、ed to provide appropriate constructionspecifications to ensure compaction to an extent that further densificationfrom traffic loadings on the completed pavement will be insignificant. Themethod suggested is to require compaction on a firm foundation of a shortcontrol strip of the material at a suita

5、ble moisture content, by means ofvibratory or other proven effective rollers or tampers, until no furtherincrease in density results. Compaction requirements should ensure that anaverage density of certain appropriate percentages of the control stripmaximum density be achieved on the balance of the

6、job; for base courses,98% is suggested as the minimum average requirement.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the othe

7、r. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footnotes(excluding those in tables and figures) shall not be consideredas requirements of the standa

8、rd.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. Reference

9、d Documents2.1 ASTM Standards:2C 136 Test Method for Sieve Analysis of Fine and CoarseAggregatesD75 Practice for Sampling AggregatesD 422 Test Method for Particle-Size Analysis of SoilsD 2419 Test Method for Sand Equivalent Value of Soils andFine AggregateD 4318 Test Methods for Liquid Limit, Plasti

10、c Limit, andPlasticity Index of SoilsD 4792 Test Method for Potential Expansion of Aggregatesfrom Hydration ReactionsE 105 Practice for Probability Sampling Of MaterialsE 122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or Proces

11、s3. General Requirements3.1 Coarse aggregate retained on the 4.75-mm (No. 4) sieveshall consist of durable particles of crushed stone, gravel, orslag capable of withstanding the effects of handling, spreading,and compacting without degradation productive of deleteriousfines. Of the particles which a

12、re retained on a 9.5-mm 38-in.sieve, at least 75% shall have two or more fractured faces.NOTE 2No standard ASTM method is recognized to be capable ofmeasuring the quality, or tendency of coarse aggregate to degrade to theextent that deleterious fines may be produced. Some local jurisdictionshave dev

13、eloped tests believed to be of value in this respect. The purchaserof material under this specification is advised to investigate the availabilityand reliability of such tests in order to specify quality requirementsappropriate to the local area.3.1.1 The fractured particle requirement of 3.1 is mod

14、ifiedwhen specified in the contract documents, providing for the useof another method for measuring interparticle friction whichhas been correlated with good field performance.1This specification is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibi

15、lity of Subcommittee D04.50 onAggregate Specifications.Current edition approved July 1, 2009. Published August 2009. Originallyapproved in 1971. Last previous edition approved in 2003 as D 2940 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service a

16、t serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2 Fine aggregate passing the 4.75-mm (No. 4) si

17、eve shallnormally consist of fines from the operation of crushing thecoarse aggregate. Where available and suitable, addition ofnatural sand or finer mineral matter, or both, is not prohibited.The fraction of the final mixture that passes the 75-m (No.200) sieve shall not exceed 60 % of the fraction

18、 passing the600-m (No. 30) sieve. The fraction passing the 425-m (No.40) sieve shall have a liquid limit no greater than 25 and shallhave a plasticity index no greater than 4. The sand equivalentvalue of the fine aggregate shall be no lower than 35.3.2.1 For material to be used as a subbase at a gre

19、ater depththan probable frost penetration, the plasticity index and sandequivalent requirements are modified to a maximum of 6 anda minimum of 30, respectively.3.3 The gradation of the final composite mixture shallconform to an approved job mix formula, within the designrange prescribed by Table 1,

20、subject to the appropriate toler-ances, and to the acceptance criteria described in Section 4.The job mix formula shall be established prior to the beginningof the work and shall not be changed without the approval ofthe engineer or his authorized representative.NOTE 3The job mix formula should be s

21、elected with due consider-ation to the footnotes appended to Table 1. In general a plotted graph ofthe fine aggregate portion should be reasonably parallel to a plot of thenearest grading limit of the design range.3.4 Aggregates that contain components subject to hydra-tion, such as steel slags, sha

22、ll be obtained from sourcesapproved by the engineer on the basis of either a satisfactoryperformance record, or of aging or other treatment known toreduce potential expansion to a satisfactory level, or ofexpansion values not greater than 0.50 % at seven days whentested in accordance with Test Metho

23、d D 4792.4. Sampling4.1 Sample each unit, or batch selected, to be tested forcompliance with the above requirements in accordance withPractice D75. A batch shall be defined as the amount ofmaterial required to fill at least one normal sized haul truck.4.2 Base acceptance decisions upon average resul

24、ts ob-tained on samples from at least three units or batches picked atrandom from each lot. A lot shall be defined as not more than3000 metric tons 3300 tons or a full days production fordelivery to a given project.4.3 In the case of grading, test each sample separately.Average values of all sieve s

25、ize determinations for a given lotshall comply with the job mix formula within the permissibletolerances shown. Results of individual batch determinationsshall conform to the job mix formula with the tolerances ofTable 1, and an additional tolerance of 2 percentage points forall sizes other than 75-

26、m (No. 200) sieve; noncomplianceshall necessitate that the entire lot be resampled or rejected.4.4 In case of requirements other than grading, the samplingfrequency and lot size shall be designated by the specifyingagency. Make at least three determinations to represent a lot.Base acceptance or reje

27、ction on the average of all determina-tions for a lot.5. Test Methods5.1 Sample the material and determine the properties enu-merated in this specification in accordance with the followingmethods:5.1.1 SamplingPractice D75.NOTE 4Attention is also called to Practices E 105 and E 122.5.1.2 Grain-Size

28、Analysis (Dry Sieving)Method C 136.5.1.3 Grain-Size Analysis (Wet Sieving and Determinationof Subsieve Size Fractions, by Hydrometer Analysis)TestMethod D 422.5.1.4 Liquid Limit Test Method D 4318.5.1.5 Plastic Limit and Plasticity IndexTest MethodD 4318.5.1.6 Sand Equivalent ValueTest Method D 2419

29、.5.1.7 ExpansionTest Method D 4792 when required forsource approval.6. Keywords6.1 aggregate; base course; subbase; coarse aggregate; fineaggregateTABLE 1 Grading Requirements for Final MixturesSieve Size (SquareOpenings)Design RangeA(MassPercentages Passing)Job Mix Toler-ances (MassPercentagesPassi

30、ng)BasesSub-basesBasesSub-bases50 mm 2 in. 100 100 2 337.5mm112 in. 95 to 100 90 to 100 65 6519.0mm34 in. 70 to 92 . 68 .9.5mm38 in. 50 to 70 . 68 .4.75 mm (No. 4) 35 to 55 30 to 60 68 610600 m (No. 30) 12 to 25 . 65 .75 m (No. 200) 0 to 8B0to12B63 65ASelect the Job Mix Formula with due regard to av

31、ailability of materials andservice requirements of project. Test results outside the design range are notprohibited, provided they are within the job mix tolerances.BDetermine by wet sieving. Where local environmental conditions (temperatureand availability of free moisture) indicate that in order t

32、o prevent damage by frostaction it is necessary to have lower percentages passing the 75-m (No. 200)sieve than permitted in Table 1, appropriate lower percentages shall be specified.When specified, the material having a diameter smaller than 20 m shall notexceed 3 mass %.D 2940/D 2940M 092ASTM Inter

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34、their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand shou

35、ld be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible 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 Stan

36、dards, 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 2940/D 2940M 093