1、Designation: C123/C123M 14 American 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 or
2、iginal 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 U.S. Departmen
3、t of Defense.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 stan
4、dard. 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 th
5、e practice.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 explan
6、atory 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 es
7、tablish 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 A
8、g-gregatesC127 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 ofAggregate to TestingSizeC1005 Specification for Referen
9、ce 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 Hydrome
10、ters3. 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 heavyliq
11、uid 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 identifyin
12、g 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 than 500 g, sensitive toat least 0.1 g: for determining the mass of coarse aggregate, abalance having a capacit
13、y of not less than 5000 g, sensitive toat least 1 g. Both balances shall conform to the accuracycriterion of the applicable sections of Specification C1005.1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregatesand is the direct responsibility of Subcommi
14、tteeC09.20 on Normal Weight Aggregates.Current edition approved Dec. 15, 2014. Published January 2015. Originallyapproved in 1936. Last previous edition approved in 2012 as C123/C123M12.DOI: 10.1520/C0123_C0123M-14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM
15、Customer 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 States15.2 Containers suitable for dryi
16、ng 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 E11, of suitable size and shape forseparating the floating particles from the heavy liquid.5.4 Hot Plate or Oven.5
17、.5 Sieves, 300-m (No. 50) and 4.75-mm (No. 4) conform-ing to Specification E11.5.6 Specific Gravity MeasurementA hydrometer conform-ing to the physical requirement sections for individual hydrom-eters of Specification E100, or a suitable combination ofgraduated glassware and balance capable of measu
18、ring theliquid specific gravity within 60.01.6. Heavy Liquid6.1 The heavy liquid shall be able to achieve the requiredspecific gravity and be readily removable from the sample. Theheavy liquid shall consist of one of the following (see 6.1.4):6.1.1 A solution of zinc chloride in water (for a specifi
19、cgravity up to about 2.0).6.1.2 A solution of zinc bromide in water (for a specificgravity up to about 2.4).6.1.3 A mixture of heavy organic liquids proportioned toachieve the desired specific gravities (see Note 2).NOTE 2Suggested liquids (and their specific gravities) include:tetrabromoethane (2.9
20、5), dibromoethane (2.70), 26 tetrachloroethane(1.63), dichloromethane (1.33).6.1.4 WarningChlorinated and brominated organic com-pounds are highly toxic and extremely dangerous to use andemit toxic fumes when heated. They shall be used only in ahood (preferably of the down-draft type) or out-of-door
21、s, andcare shall be taken to avoid inhalation or contact with the eyesor skin. They shall be handled only by personnel trained intheir use. Storage of these chemicals shall be in a securedlocation. There is no particular hazard from the fumes ofzinc-chloride solution (6.1.1) or zinc-bromide solution
22、 (6.1.2)but goggles and gloves shall be worn to prevent contact withthe eyes or skin.6.1.5 A mixture of water soluble heavy inorganic liquidsproportioned to achieve the desired specific gravities (see Note3).NOTE 3Suggested liquids (and their specific gravities) include, but arenot limited to, solut
23、ions of lithium metatungstate (2.95) and lithiumheteropolytungstates (2.85).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.7. Sampling7.1 Secure a field sample of the aggregate in accordancewith Practices D75 and D366
24、5. Reduce the sample to testportion size in accordance with 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:N
25、ominal Maximum Sizeof Aggregate(square-opening sieves)Minimum 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
26、 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 nearest 0.1 g, and br
27、ing this material to asaturated-surface-dry condition by means 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
28、, 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 theliquid that has been coll
29、ected 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 liquid.Alcohol is appro
30、priate for the chlorinated and brominatedorganic compounds and water for the zinc-chloride and zinc-bromide solutions. After the decanted particles have beenwashed, allow them to dry (see 8.1.2). Brush the dry decantedparticles from the skimmer onto the balance pan and determinethe mass to the neare
31、st 0.1 g. If more precise determination isrequired, the decanted particles shall be dried to constant massat 110 6 5 C 230 6 10 F to determine the value of W1usedfor the calculation in 9.1 (see 8.1.3).8.1.1 If the absorption as determined in accordance withTest Method C128 is known, the fine aggrega
32、te is permitted 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 bromid
33、e is used.An 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 240 F is not exceeded.8.1.3 Normally the discrepancy between oven-dry mass andsat
34、urated-surface-dry 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 aC123/C123M 1424.75-mm (No. 4) sieve. Determine the mass o
35、f the materialcoarser than the 4.75-m (No. 4) sieve to the nearest 1 g, andbring to a saturated-surface-dry condition by means of theprocedure specified in Test Method C127; then introduce it intothe heavy liquid in a suitable container. The volume of liquidshall be at least three times the absolute
36、 volume of theaggregate. Using the 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 t
37、o remove the heavyliquid (see 8.1).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 230 6 10 F to determine the va
38、lue of W1usedfor the calculation in 9.1 (see 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:L 5 W1/W2! 3100 (1)For coarse aggregate:L 5 W1/W3! 3100 (2)where:L = percentage by mass of lightweig
39、ht particles,W1= dry mass of particles that float,W2= 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, ty
40、pe andnominal maximum size,10.1.2 The mass 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
41、been conducted using this test method to 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, o
42、r float fractions, orboth.12. Keywords12.1 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 o
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