1、Designation: D 75/D 75M 09American Association StateHighway and TransportationOfficials StandardAASHTO No.: T2Standard Practice forSampling Aggregates1This standard is issued under the fixed designation D 75/D 75M; the number immediately following the designation indicates the yearof original adopti
2、on or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.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. Sc
3、ope1.1 This 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
4、 the materials.NOTE 1Sampling plans and acceptance and control tests vary with thetype of construction in which the material is used.1.2 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footnotes(excluding those in tables and figures) shall
5、not be consideredas requirements of the standard.1.3 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 other. Combiningvalues from t
6、he two systems may result in non-conformancewith the standard.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
7、-bility of regulatory limitations prior to use.NOTE 2The quality of the results produced by this standard aredependent on the competence of the personnel performing the procedureand the capability, calibration, and maintenance of the equipment used.Agencies that meet the criteria of Practice D 3666
8、are generally consid-ered capable of competent and objective testing/sampling/inspection/etc.Users of this standard are cautioned that compliance with Practice D 3666alone does not completely assure reliable results. Reliable results dependon many factors; following the suggestions of Practice D 366
9、6 or somesimilar acceptable guideline provides a means of evaluating and control-ling some of those factors.2. Referenced Documents2.1 ASTM Standards:2C 125 Terminology Relating to Concrete and ConcreteAggregatesC 702 Practice for Reducing Samples of Aggregate toTesting SizeD8 Terminology Relating t
10、o Materials for Roads and Pave-mentsD 2234/D 2234M Practice for Collection of a Gross Sampleof CoalD 3665 Practice for Random Sampling of ConstructionMaterialsD 3666 Specification for Minimum Requirements forAgen-cies Testing and Inspecting Road and Paving MaterialsE 105 Practice for Probability Sam
11、pling Of MaterialsE 122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE 141 Practice for Acceptance of Evidence Based on theResults of Probability Sampling3. Terminology3.1 Definitions:3.1.1 maximum size of aggregate, ni
12、n specifications for,or descriptions of aggregatethe 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
13、.1.3 nominal maximum aggregate size (of aggregate),nin specifications for, or descriptions of aggregatethe1This practice 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
14、June 1, 2009. Published June 2009. Originallyapproved in 1920. Last previous edition approved in 2003 as D 75 03.2For 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.smallest sieve opening through which the entire amount of theaggregate is permitted to pass. C 125,D83.1.4 nominal maximum aggregate
16、size (Superpave), ninspecifications for, or descriptions of aggregateone size largerthan the first sieve 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 de
17、finitions pub-lished in D83.1.4.2 DiscussionSpecifications on aggregates usuallystipulate a sieve opening 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.
18、4. Significance and Use4.1 Sampling is equally as important as the testing, and thesampler shall use every 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
19、 development of the potentialsource (Note 3). Samples of materials for control of theproduction at the source 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 re
20、jection decisions by the purchaser areobtained by the purchaser or his authorized representative.NOTE 3The preliminary 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
21、 enteringinto the construction. It influences the type of construction from thestandpoint of economics and governs the necessary material control toensure durability of the resulting structure, from the aggregate standpoint.This investigation should be done only by a responsible trained andexperienc
22、ed person. For more comprehensive guidance, see theAppendix.5. Securing Samples5.1 GeneralWhere practicable, 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
23、reduction in particlesize in preparation for the abrasion test unless the size of thefinished product is such 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 f
24、or proper inspection and sampling.5.3 Procedure:5.3.1 Sampling from a Flowing Aggregate Stream (Bins orBelt 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
25、 sampled, and combine to form afield sample whose mass equals or exceeds the minimumrecommended in 5.4.2. Take 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 devi
26、ce consists of a pan ofsufficient size to intercept the entire cross section of thedischarge stream and hold 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 continuous
27、ly full or nearly full to reducesegregation.NOTE 4Sampling the initial discharge or the final few tons from 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 Pra
28、ctice D 3665, fromthe production. Obtain at least three approximately equalincrements, selected at random, from 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 obtaine
29、d.Insert two templates, the shape of which conforms to the shapeof the belt in the aggregate stream on the belt, 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
30、collect thefines on the belt with a brush and dust pan and add to thecontainer.5.3.3 Sampling from Stockpiles or Transportation UnitsAvoid sampling coarse aggregate or mixed coarse and fineaggregate from stockpiles or transportation units wheneverpossible, particularly when the sampling is done for
31、thepurpose of determining aggregate properties that may bedependent upon the grading of the sample. If circumstancesmake 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
32、-ation. This approach will allow the sampling agency to use asampling plan that will give a confidence in results 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 lo
33、ts andsublots of specific sizes. General principles for sampling fromstockpiles are applicable to sampling from 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 sele
34、cted by a random method, such as PracticeD 3665, from the construction. Obtain at least three approxi-mately 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 r
35、oadway for the full depth of thematerial, taking care to exclude any underlying material.Clearly mark the specific 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 S
36、amples:5.4.1 The number of field samples (obtained by one of themethods described in 5.3) required depends on the criticalityof, and variation in, the properties to be measured. Designateeach unit from which a field sample is to be obtained prior toD 75/D 75M 092sampling. The number of field samples
37、 from the productionshould be sufficient to give the desired confidence in testresults.NOTE 5Guidance for determining the 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
38、.4.2 The field sample masses cited are tentative. Themasses must be predicated on the type and number of tests towhich the 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
39、 and specify the portion of the field sample requiredfor each specific test. Generally speaking, the amounts speci-fied in 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 app
40、licable test methods.6. Shipping Samples6.1 Transport aggregates in bags or other containers soconstructed as to preclude 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 individ
41、ual identification attached and enclosed so thatfield reporting, laboratory logging, and test reporting may befacilitated.7. Keywords7.1 aggregates; exploration of potential sources; aggregates;number and sizes needed to estimate character; aggregates;samplingD 75/D 75M 093APPENDIXES(Nonmandatory In
42、formation)X1. SAMPLING AGGREGATE FROM STOCKPILES OR TRANSPORTATION UNITSX1.1 ScopeX1.1.1 In some situations it is mandatory to sample 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 introdu
43、ce a serious bias in theresults.X1.2 Sampling from StockpilesX1.2.1 In sampling material from stockpiles it is verydifficult to ensure unbiased samples, due to the segregationwhich often occurs when material is stockpiled, with coarserparticles rolling to the outside base of the pile. For coarse orm
44、ixed coarse and fine aggregate, every effort should be madeto enlist the services of power equipment to develop a separate,small 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. Ifne
45、cessary to indicate the degree of variability existing withinthe main pile, separate samples should be drawn from separateareas of 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,
46、and at the bottomthird of the volume of the pile. A board shoved vertically intothe pile just above the sampling point aids in preventing furthersegregation. In sampling stockpiles of fine aggregate the outerlayer, which may have become segregated, should be removedand the sample taken from the mate
47、rial beneath. Samplingtubes approximately 30-mm 1.25 in. min by 2-m 6 ft min inlength may be inserted into the pile at random locations toextract a minimum of five increments of material to form thesample.X1.3 Sampling from Transportation UnitsX1.3.1 In sampling coarse aggregates from railroad cars
48、orbarges, effort should be made to enlist the services of powerequipment capable of exposing the material at various levelsand random locations. Where power equipment is not avail-able, a common procedure requires excavation of three or moretrenches across the unit at points that will, from visualap
49、pearance, give a reasonable estimate of the characteristics ofthe load. The trench bottom should be approximately level, atleast 0.3 m 1 ft in width 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 adjusting the number of incrementsaccording to the size of the truck. For fine aggregate intransportation units, sam
