1、Designation: C 123 04American Association StateHighway and Transportation StandardAASHTO No.: T 113Standard Test Method forLightweight Particles in Aggregate1This standard is issued under the fixed designation C 123; the number immediately following the designation indicates the year oforiginal adop
2、tion or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the per-centage of lightwe
3、ight particles in aggregate by means ofsink-float separation in a heavy liquid of suitable specificgravity.1.2 The values given in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concer
4、ns, 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. For a specifichazard statement, see 6.1.4.2. Referenced Documents2.1 ASTM Standards
5、:2C 33 Specification for Concrete AggregatesC 125 Terminology Relating to Concrete and ConcreteAggregatesC 127 Test Method for Density, Relative Density (SpecificGravity), and Absorption of Coarse AggregateC 128 Test Method for Density, Relative Density (SpecificGravity), and Absorption of Fine Aggr
6、egateC 702 Practice for Reducing Field Samples of Aggregate toTesting SizeC 1005 Specification for Reference Masses and Devices forDetermining Mass and Volume for Use in the PhysicalTesting of Hydraulic CementsD 75 Practice for Sampling AggregatesD 3665 Practice for Random Sampling of ConstructionMa
7、terialsE 11 Specification for Wire Cloth and Sieves for TestingPurposesE 100 Specification for ASTM Hydrometers3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology C 125.4. Significance and Use4.1 This test method is used to determine conformance withprovisions of
8、 Specification C 33 pertaining to the amount oflightweight material in fine and coarse aggregates. A heavyliquid with a specific gravity of 2.0 is used to separate particleswhich may be classified as coal or lignite. Heavier liquids areto be used to check the percentages of other lightweightparticle
9、s such as chert and shale having a specific gravity lessthan 2.40.4.2 The test method is useful in identifying porous aggre-gate particles in research activities or in petrographic analyses.5. Apparatus5.1 BalancesFor determining the mass of fine aggregates,a balance having a capacity of not less th
10、an 500 g, sensitive toat least 0.1 g: for determining the mass of coarse aggregate, abalance having a capacity of not less than 5000 g, sensitive toat least 1 g. Both balances shall conform to the accuracycriterion of the applicable sections of Specification C 1005.5.2 Containers suitable for drying
11、 the aggregate sample,and containers suitable for holding the heavy liquid during thesink-float separation.5.3 SkimmerA piece of 300-m (No. 50) sieve cloth,conforming to Specification E 11, of suitable size and shape forseparating the floating particles from the heavy liquid.5.4 Hot Plate or Oven.5.
12、5 Sieves, 300-m (No. 50) and 4.75-mm (No. 4) conform-ing to Specification E 11.5.6 Specific Gravity MeasurementA hydrometer conform-ing to the physical requirement sections for individual hydrom-eters of Specification E 100, or a suitable combination ofgraduated glassware and balance capable of meas
13、uring theliquid specific gravity within 60.01.6. Heavy Liquid6.1 The heavy liquid shall consist of one of the following(see 6.1.4):1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.20 on Normal Wei
14、ght Aggregates.Current edition approved July 1, 2004. Published July 2004. Originally approvedin 1936. Last previous edition approved in 2003 as C 123 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMS
15、tandards 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.6.1.1 A solution of zinc chloride in water (for a specificgravity up to about 2.0).6.1.2 A m
16、ixture of kerosene with 1,1,2,2-tetrabromoethane,proportioned to produce desired specific gravities. (1,1,2,2-tetrabromoethane has a specific gravity of about 2.95) (seeNote 1).6.1.3 A solution of zinc bromide in water (for a specificgravity up to about 2.4).6.1.4 WarningThe chemicals listed in 6.1.
17、2 are toxic,both by absorption through the skin and by inhalation. Theyshall be used only in a hood (preferably of the down-draft type)or out-of-doors, and care shall be taken to avoid inhalation orcontact with the eyes or skin. There is no particular hazardfrom the fumes of zinc-chloride solution (
18、6.1.1) or zinc-bromide solution (6.1.3) but goggles and gloves shall be wornto prevent contact with the eyes or skin.6.2 The specific gravity of the heavy liquid shall be main-tained within 60.01 of the specified value at all times duringthe test.NOTE 11,1,2,2-tetrabromoethane is highly toxic and ex
19、tremely dan-gerous to use and when heated emits highly toxic fumes of bromine,hydrogen bromide, and carbonyl bromide. It should be handled only bypersonnel trained and qualified in its use. Its storage should be in a securedlocation.7. Sampling7.1 Secure a field sample of the aggregate in accordance
20、with Practices D 75 and D 3665. Reduce the sample to testportion size in accordance with Practice C 702.7.2 Dry the test portion to constant mass at a temperature of110 6 5 C (230 6 9 F) before testing and sieve to removethe undersize material as specified in 8.1 and 8.2. Theminimum size of the test
21、 specimen shall be as follows:Nominal Maximum Sizeof Aggregate(square-opening sieves)Minimum Mass ofSample, g4.75 mm or smaller (No. 4 or smaller) 2009.5 mm (38 in.) 1 50012.5 to 19.0 mm (12 to34 in.) 3 00025 to 37.5 mm (1 to 112 in.) 5 00050 mm or larger (2 in. or larger) 10 0008. Procedure8.1 Fine
22、 AggregateAllow the dried test specimen of fineaggregate to cool to room temperature and then sieve over a300-m (No. 50) sieve until less than 1 % of the retainedmaterial passes the sieve in 1 min of continuous sieving.Determine the mass of the material coarser than the 300-m(No. 50) sieve to the ne
23、arest 0.1 g, and bring this material to asaturated-surface-dry condition by means of the procedurespecified in Test Method C 128 (see 8.1.1), then introduce itinto the heavy liquid (see 6.1.4) in a suitable container. Thevolume of liquid shall be at least three times the absolutevolume of the aggreg
24、ate. Pour the liquid, including the floatingparticles, into a second container, passing it through theskimmer, taking care that only the floating particles are pouredoff with the liquid and that none of the fine aggregate that sinksis decanted onto the skimmer. Return to the first container theliqui
25、d that has been collected in the second container and, afterfurther agitation of the sample by stirring, repeat the decantingprocess just described until the specimen is free of floatingparticles. Wash the decanted particles contained on the skim-mer in an appropriate solvent to remove the heavy liq
26、uid.Alcohol is appropriate for 1,1,2,2-tetrabromoethane and waterfor the zinc-chloride and zinc-bromide solutions. After thedecanted particles have been washed, allow them to dry (see8.1.2). Brush the dry decanted particles from the skimmer ontothe balance pan and determine the mass to the nearest 0
27、.1 g. Ifmore precise determination is required, the decanted particlesshall be dried to constant mass at 110 6 5 C to determine thevalue of W1used for the calculation in 9.1 (see 8.1.3).8.1.1 If the absorption as determined in accordance withTest Method C 128 is known, the fine aggregate is permitte
28、d tobe prepared for test by adding to a known mass of dry sand theamount of water it will absorb, mixing thoroughly, andpermitting the sand to stand in a covered pan for 30 min beforeuse.8.1.2 Drying shall take place in the hood or out-of-doors ifother than zinc chloride or zinc bromide is used. An
29、oven or hotplate is permitted to be used to accelerate the drying providingthat it is done in the hood or that the oven is forced-airventilated to the outside of the building and that a temperatureof 115 C is not exceeded.8.1.3 Normally the discrepancy between oven-dry mass andsaturated-surface-dry
30、mass of the decanted particles will notsignificantly affect the calculated percentage of light-weightparticles.8.2 Coarse AggregateAllow the dried test specimen ofcoarse aggregate to cool to room temperature and sieve over a4.75-mm (No. 4) sieve. Determine the mass of the materialcoarser than the 4.
31、75-m (No. 4) sieve to the nearest 1 g, andbring to a saturated-surface-dry condition by means of theprocedure specified in Test Method C 127; then introduce itinto the heavy liquid in a suitable container. The volume ofliquid shall be at least three times the absolute volume of theaggregate. Using t
32、he skimmer, remove the particles that float tothe surface, and save them. Repeatedly agitate the remainingparticles, and remove the floating particles until no additionalparticles rise to the surface. Wash the particles which areskimmed off in an appropriate solvent to remove the heavyliquid (see 8.
33、1). After the heavy liquid has been removed, allowthe particles to dry (see 8.1.2). Determine the mass of thedecanted particles to the nearest 1 g. If a more precisedetermination is required, dry the particles to constant mass at110 6 5 C to determine the value of W1used for thecalculation in 9.1 (s
34、ee 8.1.3).9. Calculation9.1 Calculate the percentage by mass of lightweight par-ticles (particles floating on the heavy liquid) as follows:For fine aggregate:L5W1/W2!3100 (1)For coarse aggregate:L5W1/W3!3100 (2)where:L = percentage by mass of lightweight particles,W1= dry mass of particles that floa
35、t,C123042W2= dry mass of portion of specimen coarser than 300-m(No. 50) sieve, andW3= dry mass of portion of specimen coarser than the4.75-mm (No. 4) sieve.10. Report10.1 Report the following information:10.1.1 Identification of the aggregate as to source, type andnominal maximum size,10.1.2 The mas
36、s of the test sample used,10.1.3 Type and specific gravity of heavy liquid used for thetest, and10.1.4 Percentage by mass of lightweight particles roundedto nearest 0.1 %.11. Precision and Bias11.1 PrecisionNo interlaboratory or intralaboratory stud-ies have been conducted using this test method to
37、determineprecision indices. The committee is seeking pertinent data fromusers of the test method.11.2 BiasBias of the test method may be estimated byrunning separate specific gravity and absorption determinationson individual particles of the separate sink, or float fractions, orboth.12. Keywords12.
38、1 aggregate; heavy liquid; lightweight particlesASTM 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 expressly advised that determination of the validity of any such patent rights,
39、 and the riskof infringement of such rights, are entirely 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 rev
40、ision of this standard or for additional standardsand should 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
41、 shouldmake your views known to the ASTM Committee on Standards, 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).C123043
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