1、Designation: C131 06C131/C131M 14Standard Test Method forResistance to Degradation of Small-Size Coarse Aggregateby Abrasion and Impact in the Los Angeles Machine1This standard is issued under the fixed designation C131;C131/C131M; the number immediately following the designation indicates theyear o
2、f original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. 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. Depar
3、tment of Defense.1. Scope*1.1 This test method covers a procedure for testing sizes of coarse aggregate aggregates with a maximum size smaller than 37.5mm (1(112 in.)in. for resistance to degradation using the Los Angeles testing machine (Note 1).NOTE 1A procedure for testing coarse aggregate larger
4、 than 19.0 mm (34 in.)in. is covered in Test Method C535. Thus coarse aggregates with amaximum size between 19 mm 34 in. and 37.5 mm 112 in. may be tested by Test Method C535 or Test Method C131/C131M.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as the s
5、tandard. The inch-pound valuesgiven in parentheses are for information only. stated in each system may not be exact equivalents; therefore, each system shall beused independently of the other. Combining values from the two systems may result in non-conformance with the standard.NOTE 2Sieve size is i
6、dentified by its standard designation in Specification E11. The Alternative designation given in parentheses is for informationonly and does not represent a different standard sieve size.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is
7、the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A6/A6M Specification for General Requirements for Rolled Structural Steel Bars, Plates,
8、 Shapes, and Sheet PilingC125 Terminology Relating to Concrete and Concrete AggregatesC136 Test Method for Sieve Analysis of Fine and Coarse AggregatesC535 Test Method for Resistance to Degradation of Large-Size Coarse Aggregate by Abrasion and Impact in the Los AngelesMachineC670 Practice for Prepa
9、ring Precision and Bias Statements for Test Methods for Construction MaterialsC702 Practice for Reducing Samples of Aggregate to Testing SizeD75 Practice for Sampling AggregatesE11 Specification for Woven Wire Test Sieve Cloth and Test Sieves3. Terminology3.1 DefinitionsFor definitions of terms used
10、 in this test method, refer to Terminology C125.4. Summary of Test Method4.1 This test is a measure of degradation of mineral aggregates of standard gradings resulting from a combination of actionsincluding abrasion or attrition, impact, and grinding in a rotating steel drum containing a specified n
11、umber of steel spheres, thenumber depending upon the grading of the test sample.As the drum rotates, a shelf plate picks up the sample and the steel spheres,carrying them around until they are dropped to the opposite side of the drum, creating an impact-crushing effect. The contents then1 This test
12、method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.20 onNormal Weight Aggregates.Current edition approved Aug. 1, 2006July 1, 2014. Published August 2006July 2014. Originally approved in 1937. Last previous
13、edition approved in 20032006 asC131-03. DOI: 10.1520/C0131-06. 06. DOI: 10.1520/C0131_C0131M-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Documen
14、t Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM reco
15、mmends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C7
16、00, West Conshohocken, PA 19428-2959. United States1roll within the drum with an abrading and grinding action until the shelf plate picks up the sample and the steel spheres, and thecycle is repeated. After the prescribed number of revolutions, the contents are removed from the drum and the aggregat
17、e portionis sieved to measure the degradation as percent loss.5. Significance and Use5.1 This test has been widely used as an indicator of the relative quality or competence of various sources of aggregate havingsimilar mineral compositions. The results do not automatically permit valid comparisons
18、to be made between sources distinctlydifferent in origin, composition, or structure. Assign specification limits with extreme care in consideration of available aggregatetypes and their performance history in specific end uses. The percent loss determined by this test method has no known consistentr
19、elationship to the percent loss for the same material when tested by Test Method C535.6. Apparatus6.1 Los Angeles MachineA Los AngelesAngles machine, conforming in all essential characteristics to the design shown inFig. 1, shall be used. The machine shall consist of a hollow steel cylinder, with a
20、wall thickness of not less than 12.4 mm at least12 mm 12 in. (Note 23) closed at both ends, conforming to the dimensions shown in Fig. 1, having an inside diameter of 7116 5 mm (2828 6 0.2 in.),in., and an inside length of 508 6 5 mm (2020 6 0.2 in.).in. The interior surface of the cylindershall be
21、free from protrusions disrupting the path of the sample and steel spheres except for the shelf described below. The cylindershall be mounted on stub shafts attached to the ends of the cylinder but not entering it, and shall be mounted in such a mannerthat it rotates with the axis in a horizontal pos
22、ition within a tolerance in slope of 1 in 100. An opening in the cylinder shall beprovided for the introduction of the test sample. A suitable, dust-tight cover shall be provided for the opening with means forFIG. 1 Los Angeles Testing MachineC131/C131M 142bolting the cover in place. The cover shall
23、 be so designed as to maintain the cylindrical contour of the interior surface unless theshelf is so located that the charge will not fall on the cover, or come in contact with it steel spheres and sample shall not impacton or near the door opening and the opening cover during the test.Aremovable st
24、eel shelf extending the full length of the cylinderand projecting inward 89 6 2 mm (3.53.5 6 0.1 in.)in. shall be mounted on the interior cylindrical surface of the cylinder, insuch a way that a plane centered between the large faces coincides with an axial plane. The shelf shall be of such thicknes
25、s andso mounted, by bolts or other suitable means, as to be firm and rigid. The position of the shelf (Note 34) shall be such that thesample and the steel spheres shall not impact on or near the opening and its cover, and that the distance from the shelf to theopening, measured along the outside cir
26、cumference of the cylinder in the direction of rotation, shall be not less than 1270 mm (50in.).50 in. Inspect the shelf periodically to determine that it is not bent either lengthwise or from its normal radial position withrespect to the cylinder. If either condition is found, repair or replace the
27、 shelf before further tests are conducted.NOTE 3This is the minimum tolerance permitted on 12.7 mm (Tolerances for wall thickness are given 12 in.) rolled steel plate as described inSpecification A6/A6M.NOTE 4The use of a shelf of wear-resistant steel, rectangular in cross section and mounted indepe
28、ndently of the cover, is preferred. However, a shelfconsisting of a section of rolled angle, properly mounted on the inside of the cover plate, may be used provided the direction of rotation is such that thecharge will be caught on the outside face of the angle.6.1.1 The machine shall be so driven a
29、nd so counterbalanced as to maintain a substantially uniform peripheral speed rotationspeed of 30 to 33 rpm (Note 45). If an angle is used as the shelf, the direction of rotation shall be such that the charge is caughton the outside surface of the angle.NOTE 5Back-lash or slip in the driving mechani
30、sm is very likely to furnish test results which are not duplicated by other Los Angeles machinesproducing constant peripheral speed.6.2 Sieves, conforming to Specification E11.6.3 BalanceA balance or scale accurate within 0.1 % of test load over the range required for this test.6.4 ChargeThe charge
31、shall consist of steel spheres averaging approximately 46.8 mm (1or ball bearings each having adiameter of between 46 mm 1 1316 in.) in diameter and in. and 48 mm 1 78 in. and each having a mass of between 390 and445 g.6.4.1 The charge, charge (steel spheres or ball bearings), (Note 56) depending up
32、on the grading of the test sample as describedin Section 8, shall be as follows:GradingNumber ofSpheresMass ofCharge, gA 12 5000 25B 11 4584 25B 11 4580 25C 8 3330 20D 6 2500 15NOTE 6Steel The total mass specified requires an average mass of each steel sphere or ball bearing of 416 g. Steel spheres
33、or ball bearings 46.0 mm(111316 in.)in. and 47.6 mm (1178 in.)in. in diameter, having a mass of approximately 400 and 440 g each, respectively, are readily available. Steelspheres or ball bearings 46.8 mm (112732 in.)in. in diameter having a mass of approximately 420 g may also be obtainable. The ch
34、arge may consist ofa mixture of these sizes conforming to the mass tolerances of 6.4 and 6.4.1.7. Sampling7.1 Obtain the field sample in accordance with Practice D75, and reduce the field sample to adequate sample size in accordancewith Practice C702.TABLE 1 Gradings of Test SamplesSieve Size (Squar
35、e Openings) Mass of Indicated Sizes, gPassing Retained on GradingA B C D37.5 mm (112 in.) 25.0 mm (1 in.) 1 250 25 . . .25.0 mm (1 in.) 19.0 mm (34 in.) 1 250 25 . . .19.0 mm (34 in.) 12.5 mm (12 in.) 1 250 10 2 500 10 . .12.5 mm (12 in.) 9.5 mm (38 in.) 1 250 10 2 500 10 . .9.5 mm (38 in.) 6.3 mm (
36、14 in.) . . 2 500 10 .6.3 mm (14 in.) 4.75-mm (No. 4) . . 2 500 10 .4.75-mm (No. 4) 2.36-mm (No. 8) . . . 5 000 10Total 5 000 10 5 000 10 5 000 10 5 000 10C131/C131M 1438. Test Sample Preparation8.1 Wash the reduced sample (see 9.1.1) and oven dry at 110 6 5 C (230 6 9 F) to substantially constant m
37、ass (see 5C 2306 9F to a constant mass, 9.1.1), separate into individual size fractions, and recombine to the grading of Table 1 most nearlycorresponding to the range of sizes in the aggregate as furnished for the work. Record the mass of the sample prior to test to thenearest 1 g.9. Procedure9.1 Pl
38、ace the test sample and the charge in the Los Angeles testing machine and rotate the machine at a speed of 30 to 33 r/minfor 500 revolutions (Note 67). After the prescribed number of revolutions, discharge the material from the machine and make apreliminary separation of the sample on a sieve coarse
39、r than the 1.70-mm (No. 12) sieve. Sieve the finer portion on a 1.70-mm(No. 12) sieve in a manner conforming to Test Method C136. Wash the material coarser than the 1.70-mm (No. 12) sieve andoven-dry at 110 6 5 C (230 6 9 F) to substantially constant mass (see 5C 230 6 9F to a constant mass, 9.1.1),
40、 and determinethe mass to the nearest 1 g (Note 78).NOTE 7Valuable information concerning the uniformity of the sample under test may be obtained by determining the loss after 100 revolutions. Theloss should be determined by dry sieving the material on the 1.70-mm sieve without washing. The ratio of
41、 the loss after 100 revolutions to the loss after500 revolutions should not greatly exceed 0.20 for material of uniform hardness. When this determination is made, take care to avoid losing any part ofthe sample; return the entire sample, including the dust of fracture, to the testing machine for the
42、 final 400 revolutions required to complete the test.NOTE 8Elimination of washing after test will seldom reduce the measured loss by more than about 0.2 % of the original sample mass.9.1.1 If the aggregate is essentially free of adherent coatings and dust, the requirement for washing after the test
43、is optional.However, in the case of referee testing, the washing procedure shall be performed.NOTE 6Valuable information concerning the uniformity of the sample under test may be obtained by determining the loss after 100 revolutions. Theloss should be determined by dry sieving the material on the 1
44、.70-mm sieve without washing. The ratio of the loss after 100 revolutions to the loss after500 revolutions should not greatly exceed 0.20 for material of uniform hardness. When this determination is made, take care to avoid losing any part ofthe sample; return the entire sample, including the dust o
45、f fracture, to the testing machine for the final 400 revolutions required to complete the test.NOTE 7Elimination of washing after test will seldom reduce the measured loss by more than about 0.2 % of the original sample mass.10. Calculation10.1 Calculate the loss (difference between the original mas
46、s and the final mass of the test sample) as a percentage of the originalmass of the test sample. Report this value as the percent loss (Note 89).NOTE 9The percent loss determined by this test method has no known consistent relationship to the percent loss for the same material when testedby Test Met
47、hod C535.Percent Loss5C 2 Y! C# 3100 (1)where:C = mass of original test sample, g, andY = final mass of the test sample, g.11. Report11.1 Report the following information:11.1.1 Identification of the aggregate as to source, type, and nominal maximum size;11.1.2 Grading designation from Table 1 used
48、for the test; and11.1.3 Loss by abrasion and impact of the sample expressed to the nearest 1 % by mass.12. Precision and Bias12.1 For nominal 19.0-mm (34-in.) maximum size coarse aggregate with percent losses in the range of 10 to 45 %, themultilaboratory coefficient of variation has been found to b
49、e 4.5 %.3 Therefore, results of two properly conducted tests from twodifferent laboratories on samples of the same coarse aggregates are not expected to differ from each other by more than 12.7 %3(95 % probability) of their average. The single-operator coefficient of variation has been found to be 2.0 %.3 Therefore, results oftwo properly conducted tests by the same operator on the same coarse aggregate are not expected to differ from each other by morethan 5.7
