1、Designation: C123/C123M 11American Association StateHighway and Transportation StandardAASHTO No.: T 113Standard Test Method forLightweight Particles in Aggregate1This standard is issued under the fixed designation C123/C123M; the number immediately following the designation indicates the yearof ori
2、ginal adoption 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 D
3、efense.1. Scope1.1 This test method covers the determination of the per-centage of lightweight particles in aggregate by means ofsink-float separation in a heavy liquid of suitable specificgravity.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.
4、The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard. Some values have only SI units because theinch-pound equivalents are not used in the prac
5、tice.NOTE 1Sieve size is identified by its standard designation in Speci-fication E11. The alternative designation given in parentheses is forinformation only and does not represent a different standard sieve size.1.3 The text of this standard references notes and footnoteswhich provide explanatory
6、material. These notes and footnotes(excluding those in tables and figures) shall not be consideredas requirements of 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 establis
7、h 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:2C33 Specification for Concrete AggregatesC125 Terminology Relating to Concrete and Concrete Ag-greg
8、atesC127 Test Method for Density, Relative Density (SpecificGravity), and Absorption of Coarse AggregateC128 Test Method for Density, Relative Density (SpecificGravity), and Absorption of Fine AggregateC702 Practice for Reducing Samples of Aggregate to Test-ing SizeC1005 Specification for Reference
9、Masses and Devices forDetermining Mass and Volume for Use in the PhysicalTesting of Hydraulic CementsD75 Practice for Sampling AggregatesD3665 Practice for Random Sampling of Construction Ma-terialsE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE100 Specification for ASTM Hydrometer
10、s3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology C125.4. Significance and Use4.1 This test method is used to determine conformance withprovisions of Specification C33 pertaining to the amount oflightweight material in fine and coarse aggregates. A heavyliquid
11、 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 lightweightparticles such as chert and shale having a specific gravity lessthan 2.40.4.2 The test method is useful in identifying p
12、orous 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 than 500 g, sensitive toat least 0.1 g: for determining the mass of coarse aggregate, abalance having a capacity o
13、f not less than 5000 g, sensitive toat least 1 g. Both balances shall conform to the accuracycriterion of the applicable sections of Specification C1005.5.2 Containers suitable for drying the aggregate sample,and containers suitable for holding the heavy liquid during thesink-float separation.1This
14、test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.20 on Normal Weight Aggregates.Current edition approved Aug. 1, 2011. Published September 2011. Originallyapproved in 1936. Last previous edition approve
15、d in 2004 as C12304. DOI:10.1520/C0123_C0123M-11.2For 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 standards Document Summary page onthe ASTM website.1Copyright A
16、STM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.3 SkimmerA piece of 300-m (No. 50) sieve cloth,conforming to Specification E11, of suitable size and shape forseparating the floating particles from the heavy liquid.5.4 Hot Plate or Oven.5.5 Sie
17、ves, 300-m (No. 50) and 4.75-mm (No. 4) conform-ing to Specification E11.5.6 Specific Gravity MeasurementAhydrometer conform-ing to the physical requirement sections for individual hydrom-eters of Specification E100, or a suitable combination ofgraduated glassware and balance capable of measuring th
18、eliquid specific gravity within 60.01.6. Heavy Liquid6.1 The heavy liquid shall consist of one of the following(see 6.1.4):6.1.1 A solution of zinc chloride in water (for a specificgravity up to about 2.0).6.1.2 A mixture of kerosene with 1,1,2,2-tetrabromoethane,proportioned to produce desired spec
19、ific gravities. (1,1,2,2-tetrabromoethane has a specific gravity of about 2.95) (seeNote 2).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 6.1.2 are toxic,both by absorption through the skin and by inhalation. Theyshall be used
20、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 (6.1.1) or zinc-bromide solution (6.1.3) but goggles and gloves shall be wornto preven
21、t 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 21,1,2,2-tetrabromoethane is highly toxic and extremely dan-gerous to use and when heated emits highly toxic fumes of bromine,hydroge
22、n 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 accordancewith Practices D75 and D3665. Reduce the sample to testportion size in accordance wit
23、h Practice C702.7.2 Dry the test portion to constant mass at a temperature of110 6 5 C 230 6 10 F before testing and sieve to removethe undersize material as specified in 8.1 and 8.2. Theminimum size of the test specimen shall be as follows:Nominal Maximum Sizeof Aggregate(square-opening sieves)Mini
24、mum Mass ofSample, g lb4.75 mm or smaller (No. 4 or smaller) 200 0.59.5 mm (38 in.) 1 500 312.5 to 19.0 mm (12 to34 in.) 3 000 725to37.5mm (1to112 in.) 5 000 1150 mm or larger (2 in. or larger) 10 000 228. Procedure8.1 Fine AggregateAllow the dried test specimen of fineaggregate to cool to room temp
25、erature 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 nearest 0.1 g, and bring this material to asaturated-surface-dry condition by m
26、eans of the procedurespecified in Test Method C128 (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 aggregate. Pour the liquid, including the floatingparticles, into a second container
27、, 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 theliquid that has been collected in the second container and, afterfurther agitation
28、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 liquid.Alcohol is appropriate for 1,1,2,2-tetrabromoethane and waterfor the zinc-
29、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 0.1 g. Ifmore precise determination is required, the decanted particlesshall be
30、 dried to constant mass at 110 6 5 C 230 6 10 F todetermine the value of W1used for the calculation in 9.1 (see8.1.3).8.1.1 If the absorption as determined in accordance withTest Method C128 is known, the fine aggregate is permitted tobe prepared for test by adding to a known mass of dry sand theamo
31、unt 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 oven or hotplate is permitted to be used to accelerate the drying prov
32、idingthat 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 240 F is not exceeded.8.1.3 Normally the discrepancy between oven-dry mass andsaturated-surface-dry mass of the decanted particles will notsignificantly affect the
33、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 4.75-m (No. 4) sieve to the nearest 1 g, andbring to a saturated-s
34、urface-dry condition by means of theprocedure specified in Test Method C127; then introduce it intothe heavy liquid in a suitable container. The volume of liquidshall be at least three times the absolute volume of theaggregate. Using the skimmer, remove the particles that float tothe surface, and sa
35、ve 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 8.1).After the heavy liquid has been removed, allowthe particles to
36、 dry (see 8.1.2). Determine the mass of thedecanted particles to the nearest 1 g. If a more preciseC123/C123M 112determination is required, dry the particles to constant mass at110 6 5 C 230 6 10 F to determine the value of W1usedfor the calculation in 9.1 (see 8.1.3).9. Calculation9.1 Calculate the
37、 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 float,W2= dry mass of portion of specimen coa
38、rser 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 mass of the test sample used,10.1.3 Type and specif
39、ic 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 determineprecision indices. The committee is see
40、king 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. Keywords12.1 aggregate; heavy liquid; lightweight particles
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