1、Designation: D2940/D2940M 15Standard Specification forGraded Aggregate Material For Bases or Subbases forHighways or Airports1This standard is issued under the fixed designation D2940/D2940M; the number immediately following the designation indicates theyear of original adoption or, in the case of r
2、evision, 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 U.S. Department of Defense.1. Scope1.1 This specif
3、ication 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 cautio
4、ned 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 suit
5、able 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 oth
7、er. 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 stand
8、ard.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. Referenc
9、ed Documents2.1 ASTM Standards:2C136 Test Method for Sieve Analysis of Fine and CoarseAggregatesD75 Practice for Sampling AggregatesD422 Test Method for Particle-Size Analysis of SoilsD2419 Test Method for Sand Equivalent Value of Soils andFine AggregateD4318 Test Methods for Liquid Limit, Plastic L
10、imit, andPlasticity Index of SoilsD4792 Test Method for Potential Expansion of Aggregatesfrom Hydration ReactionsD5821 Test Method for Determining the Percentage ofFractured Particles in Coarse AggregateE105 Practice for Probability Sampling of MaterialsE122 Practice for Calculating Sample Size to E
11、stimate, WithSpecified Precision, the Average for a Characteristic of aLot or Process3. 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 com
12、pacting without degradation productive of deleteriousfines. Of the particles which are 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 t
13、o theextent that deleterious fines may be produced. Some local jurisdictionshave developed 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 requirements
14、appropriate to the local area.3.1.1 The fractured particle requirement of 3.1 is modifiedwhen specified in the contract documents, providing for the use1This specification is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04
15、.50 onAggregate Specifications.Current edition approved June 1, 2015. Published July 2015. Originally approvedin 1971. Last previous edition approved in 2009 as D2940/D2940M 09. DOI:10.1520/D2940_D2940M-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
16、Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1of another method for measuring interpart
17、icle friction whichhas been correlated with good field performance.3.2 Fine aggregate passing the 4.75-mm (No. 4) sieve 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 pr
18、ohibited.The fraction of the final mixture that passes the 75-m (No.200) sieve shall not exceed 60 % of the fraction 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
19、 equivalentvalue of the fine aggregate shall be no lower than 35.3.2.1 For material to be used as a subbase at a greater 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
20、 final composite mixture shallconform to an approved job mix formula, within the designrange prescribed by Table 1, subject to the appropriatetolerances, and to the acceptance criteria described in Section4. The job mix formula shall be established prior to thebeginning of the work and shall not be
21、changed without theapproval of the engineer or his authorized representative.NOTE 3The job mix formula should be selected 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 gradin
22、g limit of the design range.3.4 Aggregates that contain components subject tohydration, such as steel slags, shall 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 satisfac
23、tory level, or ofexpansion values not greater than 0.50 % at seven days whentested in accordance with Test Method D4792.4. 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 of
24、material required to fill at least one normal sized haul truck.4.2 Base acceptance decisions upon average results 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 forde
25、livery to a given project.4.3 In the case of grading, test each sample separately.Average values of all sieve size 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 formul
26、a with the tolerances ofTable 1, and an additional tolerance of 2 percentage points forall sizes other than 75-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 de
27、signated by the specifyingagency. Make at least three determinations to represent a lot.Base acceptance or rejection 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 followingm
28、ethods:5.1.1 SamplingPractice D75.NOTE 4Attention is also called to Practices E105 and E122.5.1.2 Grain-Size Analysis (Dry Sieving)Method C136.5.1.3 Grain-Size Analysis (Wet Sieving and Determinationof Subsieve Size Fractions, by Hydrometer Analysis)TestMethod D422.5.1.4 Liquid Limit Test Method D43
29、18.5.1.5 Plastic Limit and Plasticity IndexTest MethodD4318.5.1.6 Sand Equivalent ValueTest Method D2419.5.1.7 ExpansionTest Method D4792 when required forsource approval.5.1.8 Fractured ParticlesTest Method D5821.6. Keywords6.1 aggregate; base course; subbase; coarse aggregate; fineaggregateTABLE 1
30、 Grading Requirements for Final MixturesSieve Size (SquareOpenings)Design RangeA(MassPercentages Passing)Job Mix Toler-ances (MassPercentagesPassing)BasesSub-basesBasesSub-bases50 mm 2 in. 100 100 2 337.5mm112 in. 95 to 100 90 to 100 5 519.0mm34 in. 70 to 92 . 8 .9.5mm38 in. 50 to 70 . 8 .4.75 mm (N
31、o. 4) 35 to 55 30 to 60 8 10600 m (No. 30) 12 to 25 . 5 .75 m (No. 200) 0 to 8B0to12B3 5ASelect the Job Mix Formula with due regard to availability of materials andservice requirements of project. Test results outside the design range are notprohibited, provided they are within the job mix tolerance
32、s.BDetermine by wet sieving. Where local environmental conditions (temperatureand availability of free moisture) indicate that in order to 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
33、shall be specified.When specified, the material having a diameter smaller than 20 m shall notexceed 3 mass %.D2940/D2940M 152ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are ex
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