1、Designation: C535 12Standard Test Method forResistance to Degradation of Large-Size Coarse Aggregateby Abrasion and Impact in the Los Angeles Machine1This standard is issued under the fixed designation C535; the number immediately following the designation indicates the year oforiginal adoption or,
2、in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript 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. Scope*1.1
3、 This test method covers testing sizes of coarse aggregatelarger than 19 mm (34 in.) for resistance to degradation usingthe Los Angeles testing machine (Note 1).NOTE 1A procedure for testing coarse aggregate smaller than 37.5mm (112 in.) is covered in Test Method C131.1.2 This standard does not purp
4、ort 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-bility of regulatory limitations prior to use.1.3 The values stated in SI units are to be re
5、garded as thestandard. The inch-pound values given in parentheses are forinformation only.2. Referenced Documents2.1 ASTM Standards:2C125 Terminology Relating to Concrete and Concrete Ag-gregatesC131 Test Method for Resistance to Degradation of Small-Size Coarse Aggregate by Abrasion and Impact in t
6、he LosAngeles MachineC136 Test Method for Sieve Analysis of Fine and CoarseAggregatesC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsC702 Practice for Reducing Samples ofAggregate to TestingSizeD75 Practice for Sampling AggregatesE11 Specification
7、for Woven Wire Test Sieve Cloth and TestSieves3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology C125.4. Summary of Test Method4.1 This test is a measure of degradation of mineral aggre-gates of standard gradings resulting from a combination ofactions including
8、abrasion or attrition, impact, and grinding ina rotating steel drum containing 12 steel spheres. As the drumrotates, a shelf plate picks up the sample and the steel spheres,carrying them around until they are dropped to the oppositeside of the drum, creating an impact-crushing effect. Thecontents th
9、en roll within the drum with an abrading andgrinding action until the shelf plate picks up the sample and thesteel spheres, and the cycle is repeated. After the prescribednumber of revolutions, the contents are removed from the drumand the aggregate portion is sieved to measure the degradationas per
10、cent loss.5. Significance and Use5.1 The test has been widely used as an indicator of therelative quality or competence of various sources of aggregatehaving similar mineral compositions. The results do notautomatically permit valid comparisons to be made betweensources distinctly different in origi
11、n, composition, or structure.Assign specification limits with extreme care in considerationof available aggregate types and their performance history inspecific end uses.6. Apparatus6.1 The Los Angeles Machine shall conform to the require-ments of Test Method C131.6.1.1 The operation and maintenance
12、 of the machine shallbe as prescribed in Test Method C131.6.2 Sieves, conforming to Specification E11.6.3 BalanceA balance or scale accurate within 0.1 % oftest load over the range required for this test6.4 ChargeThe charge (Note 2) shall consist of 12 steelspheres averaging approximately 47 mm (127
13、32 in.) in1This 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 Dec. 15, 2012. Published January 2013. Originallyapproved in 1964. Last previous
14、edition approved in 2009 as C535 09. DOI:10.1520/C0535-12.2For 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.*A
15、Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1diameter, each having a mass between 390 and 445 g, andhaving a total mass of 5000 6 25 g.NOTE 2Steel ball bearings 46.0 mm
16、(11316 in.) and 47.6 mm (178 in.)in diameter, having a mass approximately 400 and 440 g each,respectively, are readily available. Steel spheres 46.8 mm (12732 in.) indiameter having a mass approximately 420 g may also be obtainable. Thecharge may consist of a mixture of these sizes conforming to the
17、 totalmass tolerance of 6.4.7. Sampling7.1 Obtain the field sample in accordance with Practice D75and reduce to an adequate sample size in accordance withPractice C702.8. Test Sample Preparation8.1 Wash the reduced sample and oven dry at 110 6 5C(230 6 9F) to substantially constant mass, separate in
18、toindividual size fractions, and recombine to the grading of Table1 most nearly corresponding to the range of sizes in theaggregate as furnished for the work. Record the mass of thesample prior to test to the nearest 1 g.9. Procedure9.1 Place the test sample and charge in the Los Angelestesting mach
19、ine and rotate the machine at 30 to 33 r/min for1000 revolutions (Note 3). After the prescribed number ofrevolutions, discharge the material from the machine and makea preliminary separation of the sample on a sieve coarser thanthe 1.70-mm (No. 12) sieve. Sieve the finer portion on a1.70-mm sieve in
20、 a manner conforming to Test Method C136.Wash the material coarser than the 1.70-mm sieve and oven dryat 110 6 5C (230 6 9F) to substantially constant mass, anddetermine the mass to the nearest1g.9.1.1 If the aggregate is essentially free of adherent coatingsand dust, the requirement for washing aft
21、er the test is optional.However, in the case of referee testing, the washing procedureshall be performed. Elimination of washing after test willseldom reduce the measured loss by more than about 0.2 % ofthe original sample mass.NOTE 3Valuable information concerning the uniformity of the sampleunder
22、test may be obtained by determining the loss after 200 revolutions.This loss should be determined by dry sieving the material on the1.70-mm (No. 12) sieve without washing. The ratio of the loss after 200revolutions to the loss after 1000 revolutions should not greatly exceed0.20 for material of unif
23、orm hardness. When this determination is made,take care to avoid losing any part of the sample; return the entire sample,including the dust of fracture, to the testing machine for the final 800revolutions required to complete the test.10. Calculation10.1 Calculate the loss (the difference between th
24、e originalmass and the final mass of the test sample) as a percentage ofthe original mass of the test sample (Note 4).NOTE 4The percent loss determined by this method has no knownconsistent relationship to the percent loss for the same material whentested by Test Method C131.11. Report11.1 Report th
25、e following information:11.2 Identification of the aggregate as to source, type, andnominal size, and11.3 Grading designation from Table 1 used for the test, and11.4 Loss by abrasion and impact of the sample expressed tothe nearest 1 % by mass.12. Precision and Bias12.1 Precision12.1.1 Single Operat
26、or PrecisionThe single-operator co-efficient of variation has been found to be 2.7 %.3Therefore,results of two properly conducted tests by the same operator onthe same material are not expected to differ by more than 7.6% of their average.312.1.2 Multilaboratory PrecisionThe multilaboratory co-effic
27、ient of variation has been found to be 4.2 %.3Therefore,results of two different laboratories on identical samples of thesame material are not expected to differ from each other bymore than 11.8 % of their average.3NOTE 5These precision values were obtained in an interlaboratorystudy that included 1
28、0 laboratories and one type of aggregate (Limestone)that had an average mass loss 28.5 %. Each laboratory was given anaggregate sample conforming to grading 1 and another sample conformingto grading 2. The results for the two gradings were averaged. The detailsare given in Research Report RR:C09-104
29、2.412.2 Bias12.2.1 Because there is no accepted reference materialsuitable for determining the bias in this test method, nostatement on bias is made.3These numbers represent, respectively, the (1s%) and (d2s%) limits asdescribed in Practice C670.4Supporting data have been filed at ASTM International
30、 Headquarters and maybe obtained by requesting Research Report RR:C09-1042. ContactASTM CustomerService at serviceastm.org.TABLE 1 Gradings of Test SamplesSieve Size, mm (in.) (Square Openings) Mass of Indicated Sizes, gPassing Retained onGrading12375 (3) 63 (212) 2 500 50 . .63 (212) 50(2) 250050 .
31、 .50 (2) 37.5 (112) 500050 500050 .37.5 (112) 25.0 (1) . 5 000 25 5 000 2525.0 (1) 19.0 (34) . . 5 000 25Total 10 000 100 10 000 75 10 000 50C535 12213. Keywords13.1 abrasion; aggregate (coarse; large size); degradation;impact; Los Angeles machineAPPENDIX(Nonmandatory Information)X1. MAINTENANCE OF
32、SHELFX1.1 The shelf of the Los Angeles machine is subject tosevere surface wear and impact. With use, the working surfaceof the shelf is peened by the balls and tends to develop a ridgeof metal parallel to and about 32 mm (114 in.) from the junctionof the shelf and the inner surface of the cylinder.
33、 If the shelf ismade from a section of rolled angle, not only may this ridgedevelop but the shelf itself may be bent longitudinally ortransversely from its proper position.X1.2 The shelf should be inspected periodically to deter-mine that it is not bent either lengthwise or from its normalradial pos
34、ition with respect to the cylinder. If either conditionis found, the shelf should be repaired or replaced before furthertests are made. The influence on the test result of the ridgedeveloped by peening of the working face of the shelf is notknown. However, for uniform test conditions, it is recom-me
35、nded that the ridge be ground off if its height exceeds 0.1 in.(2 mm).SUMMARY OF CHANGESCommittee C09 has identified the location of selected changes to this test method since the last issue,C535 09, that may impact the use of this test method. (Approved December 15, 2012)(1) Revised Section 12 Prec
36、ision and Bias.ASTM 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, and the riskof infringement of s
37、uch 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 revision of this standard or for add
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39、he 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).C535 123
