1、Designation: D 75 03American Association StateHighway and TransportationOfficials StandardAASHTO No.: T2Standard Practice forSampling Aggregates1This standard is issued under the fixed designation D 75; the number immediately following the designation indicates the year of originaladoption or, in th
2、e case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon (e) 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
3、 practice covers sampling of coarse and fine aggre-gates for the following purposes:1.1.1 Preliminary investigation of the potential source ofsupply,1.1.2 Control of the product at the source of supply,1.1.3 Control of the operations at the site of use, and1.1.4 Acceptance or rejection of the materi
4、als.NOTE 1Sampling plans and acceptance and control tests vary with thetype of construction in which the material is used. Attention is directed toPractices E 105 and D 3665.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibil
5、ity 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:C 125 Terminology Relating to Concrete and ConcreteAggregates2C 702 Practice for Reducing Field Sam
6、ples of Aggregate toTesting Size2D8 Terminology Relating to Materials for Roads and Pave-ments3D 2234/D 2234M Test Method for Collection of a GrossSample of Coal4D 3665 Practice for Random Sampling of ConstructionMaterials3E 105 Practice for Probability Sampling of Materials5E 122 Practice for Calcu
7、lating Sample Size to Estimate,With a Specified Tolerable Error, the Average Quality of aLot or Process5E 141 Practice for Acceptance of Evidence Based on theResults of Probability Sampling53. Terminology3.1 Definitions:3.1.1 maximum size of aggregate, nin specifications for,or descriptions of aggre
8、gatethe smallest sieve openingthrough which the entire amount of aggregat is required topass. C 125, D 83.1.2 maximum aggregate size, (Superpave) nin specifi-cations for, or descriptions of aggregateone size larger thanthe nominal maximum aggregate size.3.1.3 nominal maximum aggregate size (of aggre
9、gate),nin specifications for, or descriptions of aggregatethesmallest sieve opening through which the entire amount of theaggregate is permitted to pass. C 125, D 83.1.4 nominal maximum aggregate size (Superpave), ninspecifications for, or descriptions of aggregateone size largerthan the first sieve
10、 that retains more than 10 % aggregate.3.1.4.1 DiscussionThese definitions in 3.1.2 and 3.1.4apply to hot mix asphalt (HMA) mixtures designed using theSuperpave system only, and differ from the definitions pub-lished in D83.1.4.2 DiscussionSpecifications on aggregates usuallystipulate a sieve openin
11、g through which all of the aggregatemay, but not need to, pass so that a slated maximum portion ofthe aggregate may be retained on that sieve.Asieve opening sodesigned is the nominal maximum size.4. Significance and Use4.1 Sampling is equally as important as the testing, and thesampler shall use eve
12、ry precaution to obtain samples that willshow the nature and condition of the materials which theyrepresent.4.2 Samples for preliminary investigation tests are obtainedby the party responsible for development of the potentialsource (Note 2). Samples of materials for control of theproduction at the s
13、ource or control of the work at the site of useare obtained by the manufacturer, contractor, or other partiesresponsible for accomplishing the work. Samples for tests to beused in acceptance or rejection decisions by the purchaser areobtained by the purchaser or his authorized representative.1This p
14、ractice is under the jurisdiction of ASTM Committee D04 on Road andPaving Materials and is the direct responsibility of Subcommittee D04.30 onMethods of Sampling.Current edition approved July 10, 2003. Published September 2003. Originallyapproved in 1920. Last previous edition approved in 1997 as D
15、75 97.2Annual Book of ASTM Standards, Vol 04.02.3Annual Book of ASTM Standards, Vol 04.03.4Annual Book of ASTM Standards, Vol 05.05.5Annual Book of ASTM Standards, Vol 14.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 2The p
16、reliminary investigation and sampling of potentialaggregate sources and types occupies a very important place in determin-ing the availability and suitability of the largest single constituent enteringinto the construction. It influences the type of construction from thestandpoint of economics and g
17、overns the necessary material control toensure durability of the resulting structure, from the aggregate standpoint.This investigation should be done only by a responsible trained andexperienced person. For more comprehensive guidance, see theAppendix.5. Securing Samples5.1 GeneralWhere practicable,
18、 samples to be tested forquality shall be obtained from the finished product. Samplesfrom the finished product to be tested for abrasion loss shall notbe subject to further crushing or manual reduction in particlesize in preparation for the abrasion test unless the size of thefinished product is suc
19、h that it requires further reduction fortesting purposes.5.2 InspectionThe material shall be inspected to deter-mine discernible variations. The seller shall provide suitableequipment needed for proper inspection and sampling.5.3 Procedure:5.3.1 Sampling from a Flowing Aggregate Stream (Bins orBelt
20、Discharge)Select units to be sampled by a randommethod, such as Practice D 3665, from the production. Obtainat least three approximately equal increments, selected atrandom from the unit being sampled, and combine to form afield sample whose mass equals or exceeds the minimumrecommended in 5.4.2. Ta
21、ke each increment from the entirecross section of the material as it is being discharged. It isusually necessary to have a special device constructed for useat each particular plant. This device consists of a pan ofsufficient size to intercept the entire cross section of thedischarge stream and hold
22、 the required quantity of materialwithout overflowing. A set of rails may be necessary to supportthe pan as it is passed under the discharge stream. Insofar as ispossible, keep bins continuously full or nearly full to reducesegregation.NOTE 3Sampling the initial discharge or the final few tons from
23、a binor conveyor belt increases the chances of obtaining segregated materialand should be avoided.5.3.2 Sampling from the Conveyor BeltSelect units to besampled by a random method, such as Practice D 3665, fromthe production. Obtain at least three approximately equalincrements, selected at random, f
24、rom the unit being sampledand combine to form a field sample whose mass equals orexceeds the minimum recommended in 5.4.2. Stop the con-veyor belt while the sample increments are being obtained.Insert two templates, the shape of which conforms to the shapeof the belt in the aggregate stream on the b
25、elt, and space themsuch that the material contained between them will yield anincrement of the required weight. Carefully scoop all materialbetween the templates into a suitable container and collect thefines on the belt with a brush and dust pan and add to thecontainer.5.3.3 Sampling from Stockpile
26、s or Transportation UnitsAvoid sampling coarse aggregate or mixed coarse and fineaggregate from stockpiles or transportation units wheneverpossible, particularly when the sampling is done for thepurpose of determining aggregate properties that may bedependent upon the grading of the sample. If circu
27、mstancesmake it necessary to obtain samples from a stockpile of coarseaggregate or a stockpile of combined coarse and fine aggregate,design a sampling plan for the specific case under consider-ation. This approach will allow the sampling agency to use asampling plan that will give a confidence in re
28、sults obtainedtherefrom that is agreed upon by all parties concerned to beacceptable for the particular situation. The sampling plan shalldefine the number of samples necessary to represent lots andsublots of specific sizes. General principles for sampling fromstockpiles are applicable to sampling f
29、rom trucks, rail cars,barges, or other transportation units. For general guidance insampling from stockpiles, see the Appendix.5.3.4 Sampling from Roadway (Bases and Subbases)Sample units selected by a random method, such as PracticeD 3665, from the construction. Obtain at least three approxi-mately
30、 equal increments, selected at random from the unitbeing sampled, and combine to form a field sample whosemass equals or exceeds the minimum recommended in 5.4.2.Take all increments from the roadway for the full depth of thematerial, taking care to exclude any underlying material.Clearly mark the sp
31、ecific areas from which each increment isto be removed: a metal template placed over the area is adefinite aid in securing approximately equal incrementweights.5.4 Number and Masses of Field Samples:5.4.1 The number of field samples (obtained by one of themethods described in 5.3) required depends o
32、n the criticalityof, and variation in, the properties to be measured. Designateeach unit from which a field sample is to be obtained prior tosampling. The number of field samples from the productionshould be sufficient to give the desired confidence in testresults.NOTE 4Guidance for determining the
33、number of samples required toobtain the desired level of confidence in test results may be found in TestMethod D 2234/D 2234M, Practice E 105, Practice E 122, and PracticeE 141.5.4.2 The field sample masses cited are tentative. Themasses must be predicated on the type and number of tests towhich the
34、 material is to be subjected and sufficient materialobtained to provide for the proper execution of these tests.Standard acceptance and control tests are covered by ASTMstandards and specify the portion of the field sample requiredfor each specific test. Generally speaking, the amounts speci-fied in
35、 Table 1 will provide adequate material for routinegrading and quality analysis. Extract test portions from thefield sample according to Practice C 702 or as required byother applicable test methods.6. Shipping Samples6.1 Transport aggregates in bags or other containers soconstructed as to preclude
36、loss or contamination of any part ofthe sample, or damage to the contents from mishandling duringshipment.6.2 Shipping containers for aggregate samples shall havesuitable individual identification attached and enclosed so thatfield reporting, laboratory logging, and test reporting may befacilitated.
37、D75 0327. Keywords7.1 aggregates; exploration of potential sources; aggregates;number and sizes needed to estimate character; aggregates;samplingAPPENDIXES(Nonmandatory Information)X1. SAMPLING AGGREGATE FROM STOCKPILES OR TRANSPORTATION UNITSX1.1 ScopeX1.1.1 In some situations it is mandatory to sa
38、mple aggre-gates that have been stored in stockpiles or loaded into railcars, barges, or trucks. In such cases the procedure shouldensure that segregation does not introduce a serious bias in theresults.X1.2 Sampling from StockpilesX1.2.1 In sampling material from stockpiles it is verydifficult to e
39、nsure unbiased samples, due to the segregationwhich often occurs when material is stockpiled, with coarserparticles rolling to the outside base of the pile. For coarse ormixed coarse and fine aggregate, every effort should be madeto enlist the services of power equipment to develop a separate,small
40、sampling pile composed of materials drawn from variouslevels and locations in the main pile after which severalincrements may be combined to compose the field sample. Ifnecessary to indicate the degree of variability existing withinthe main pile, separate samples should be drawn from separateareas o
41、f the pile.X1.2.2 Where power equipment is not available, samplesfrom stockpiles should be made up of at least three incrementstaken from the top third, at the mid-point, and at the bottomthird of the volume of the pile. A board shoved vertically intothe pile just above the sampling point aids in pr
42、eventing furthersegregation. In sampling stockpiles of fine aggregate the outerlayer, which may have become segregated, should be removedand the sample taken from the material beneath. Samplingtubes approximately 30-mm min by 2-m min in length may beinserted into the pile at random locations to extr
43、act a minimumof five increments of material to form the sample.X1.3 Sampling from Transportation UnitsX1.3.1 In sampling coarse aggregates from railroad cars orbarges, effort should be made to enlist the services of powerequipment capable of exposing the material at various levelsand random location
44、s. Where power equipment is not avail-able, a common procedure requires excavation of three or moretrenches across the unit at points that will, from visualappearance, give a reasonable estimate of the characteristics ofthe load. The trench bottom should be approximately level, atleast 0.3 m in widt
45、h and in depth below the surface. Aminimum of three increments from approximately equallyspaced points along each trench should be taken by pushing ashovel downward into the material. Coarse aggregate in trucksshould be sampled in essentially the same manner as for railcars or barges, except for adj
46、usting the number of incrementsaccording to the size of the truck. For fine aggregate intransportation units, sampling tubes as described in X1.2 maybe used to extract an appropriate number of increments to formthe sample.TABLE 1 Size of SamplesAggregate SizeAField Sample Mass, min, kgBFine Aggregat
47、e2.36 mm 104.75 mm 10Coarse Aggregate9.5 mm 1012.5 mm 1519.0 mm 2525.0 mm 5037.5 mm 7550 mm 10063 mm 12575 mm 15090 mm 175AFor processed aggregates, use the nominal maximum size as indicated by theappropriate specification or description. If the specification or description does notindicate a nomina
48、l maximum size (for example, a sieve size indicating 90-100%passing), use the maximum size (that sieve indicating 100% passing).BFor combined coarse and fine aggregates (for example, base or subbaseaggregate), the minimum weight shall be coarse aggregate minimum mass plus 10kg.D75 033X2. EXPLORATION
49、 OF POTENTIAL AGGREGATE SOURCESX2.1 ScopeX2.1.1 Sampling for evaluation of potential aggregatesources should be performed by a responsible trained andexperienced person. Because of the wide variety of conditionsunder which sampling may have to be done it is not possible todescribe detailed procedures applicable to all circumstances.This appendix is intended to provide general guidance and listmore comprehensive references.X2.2 Sampling Stone from Quarries or LedgesX2.2.1 InspectionThe ledge or quarry face should beinspected to determine discernible variations or st
