1、Designation: C 944/C 944M 99 (Reapproved 2005)e1Standard Test Method forAbrasion Resistance of Concrete or Mortar Surfaces by theRotating-Cutter Method1This standard is issued under the fixed designation C 944/C 944M; the number immediately following the designation indicates the yearof original ado
2、ption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEThe designation was changed editorially to agree with the existing values st
3、atement in the Scope in March 2008.1. Scope1.1 This test method covers a procedure for determining theresistance of either concrete or mortar to abrasion. This testmethod is similar to Procedure B of Test Method C 779/C 779M.1.2 The values stated in SI units or inchpound units are tobe regarded sepa
4、rately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each systemshall be used independently of the other. Combining valuesfrom the two systems may result in nonconformance with thestandard.1.3 This standard does not purport to address all of thesafety concerns
5、, 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.2. Referenced Documents2.1 ASTM Standards:2C42 Test Method for Obtaining and Testing D
6、rilled Coresand Sawed Beams of ConcreteC 418 Test Method for Abrasion Resistance of Concrete bySandblastingC 779/C 779M Test Method for Abrasion Resistance ofHorizontal Concrete Surfaces3. Significance and Use3.1 This test method gives an indication of the relative wearresistance of mortar and concr
7、ete based on testing of cored orfabricated specimens. This test method has been successfullyused in the quality control of highway and bridge concretesubject to traffic. Primarily intended for use on the top ends of152-mm 6-in. diameter concrete cores, mortar specimens, orother samples of concrete o
8、f insufficient test area to permit theconduct of tests by Test Method C 418 or C 779/C 779M, thistest method is also applicable on concrete surfaces in place bymeasuring the abrasion loss as described in Section 9, Proce-dure B, of Test Method C 779/C 779M.4. Apparatus4.1 Abrasion DeviceA drill pres
9、s or similar device with achuck capable of holding and rotating the abrading cutter at aspeed of 200 r/min and exerting a force of either a normal loadof 98 6 1 N 22 6 0.2 lbf or a double load of 197 6 2 N 446 0.4 lbf on the test specimen surface. Fig. 1 shows acommercial drill press and Fig. 2 illu
10、strates details of therotating cutter. The difficulty in maintaining a constant load onthe abrading cutter when using the lever, gear, and springsystem of a drill press has been eliminated by placing thedesired load directly upon the spindle that turns the cutter. Themachine consists essentially of
11、a frame that supports the drivemotor, stepped pulley, and spindle. A clamping device to holdthe specimen is built into the base.4.2 Rotating CutterA rotating cutter similar to that shownin Fig. 2 and Fig. 3 shall be used in which 22 37.5 mm 1.5 in.diameter dressing wheels and 24 25.4 to 31.75 mm 1 t
12、o 1.25in. diameter washers are mounted. The washers as receivedshall be stacked and locked on a bolt for the purpose ofreducing their diameter to the specified range to avoid restrict-ing abrasion of the concrete by the washers. Cutter assembly,including washers, shall be locked onto horizontal rods
13、 suchthat individual dressing wheels are free to turn independently.The overall diameter of the cutter or the diameter of thecircular area abraded is 82.5 mm 314 in. Care shall be takento achieve constant contact between the rotating cutter and theentire test surface of the sample. This can be bette
14、r accom-plished if the cutters have a swivel connection allowing somevertical movement. If the dressing wheels have one roundededge, they shall be mounted with the rounded edge toward thevertical shaft. The individual grinding wheel dressers on thehorizontal shaft of the cutter shall be repositioned
15、 whenever a1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.62 on Abrasion Testing.Current edition approved May 1, 2005. Published June 2005. Originallyapproved in 1980. Last previous edition appr
16、oved in 1990 as C 944 90a.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 ASTM International, 100
17、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.change in the diameter of the outer cutters becomes apparent.This is accomplished by reversing each set of dressing wheelsto bring the smaller diameter cutters toward the vertical shaft.4.2.1 In making a test, the rotati
18、ng cutter is held in a raisedposition by means of the rod provided, the specimen clampedsecurely in position, and motor started. The rotating cutter isthen lowered into contact with the specimen for a specifiedtime, after which the cutter is raised.4.2.2 Aset of dressing wheels shall be replaced per
19、iodically,preferably after each 90 min of use. The washers may beground or replaced to maintain the proper diameter.4.3 BalanceA balance having a capacity of at least 4 kg,and accurate to at least 0.1 g.4.4 Leveling PlateThe base plate upon which the speci-men rests shall be capable of rotating in t
20、he horizontal plane sothat the specimens when placed thereon can be positioned tosecure maximum contact with the rotating cutter throughoutthe full test area.5. Sampling5.1 Cores shall be taken in accordance with Test MethodC42.6. Specimens6.1 The specimens used in this test shall be of any size and
21、shape that can be accommodated by the abrasion device andthe balance provided. The surface to be tested shall be eitherformed or finished and shall be positioned in the plane ofcontact of the cutter.7. Procedure7.1 Determine the mass of the specimen to the nearest 0.1 g.7.2 Fasten the specimens secu
22、rely in the abrasion device sothat the surface to be tested is normal to the shaft.7.3 Mount the rotating cutter device in the abrasion device.7.4 Start the motor and lower the cutter slowly until just incontact with the surface of the specimen.FIG. 1 Rotating-Cutter Drill PressC 944/C 944M 99 (2005
23、)e127.5 Continue abrasion with a normal or a double load on thespecimen for 2 min after contact between the cutter and thesurface. At the end of each 2-min abrasion period, remove thetest specimen from the device and clean surfaces to removedebris using a soft brush or blow the surface with air.Dete
24、rmine the specimen mass to the nearest 0.1 g. Theminimum test schedule shall involve three 2-min periodsconducted on three separate areas of representative surfaces ofthe concrete or mortar.7.6 For concrete that is highly resistant to abrasion addi-tional testing may be required. Doubling the applie
25、d load, orthe time, or both, as shown in the following chart, shouldprovide more comprehensive information on such concrete.Abrasion Cycle Load, N (lbf) Test Frequency/PeriodA NormalB Double load98 (22)197 (44)3 3 2min3 3 2min7.7 When testing surfaces in place, or when the depth ofwear is to be dete
26、rmined due to significant differences insurface density, refer to Test Method C 779/C 779M ProcedureB, to determine abraded depth using the apparatus in this testmethod.8. Report8.1 Report the following information on:8.1.1 Description of surface,8.1.2 Size of specimen,8.1.3 Type of finish,8.1.4 Con
27、crete compaction, age, and strength,8.1.5 Applied surface treatment,8.1.6 Time of abrasion and load used (normal or double),8.1.7 Average loss in grams or depth of wear in millimetresand,8.1.8 Loss in mass and time abraded.9. Precision and Bias9.1 PrecisionCriteria for judging the acceptability ofab
28、rasion resistance test results obtained by this test method areas follows:9.1.1 Normal Load ConditionThe single-operator coeffi-cient of variation has been found to be 21 %. Therefore, theresults of two properly conducted tests by the same operator onsimilar samples should not differ from each other
29、 by more than59 % of the average.9.1.2 Double Load ConditionThe single-operator coeffi-cient of variation has been found to be 12.6 %. Therefore, theresults of two properly conducted tests by the same operator onsimilar samples should not differ from each other by more than36 % of their average.9.2
30、BiasThe procedure in this test method has no biasbecause the value of abrasion resistance of concrete surfacescan be only defined in terms of a test method.10. Keywords10.1 abrasion; concrete; impact; mortar; wearFIG. 2 Typical Rotating CuttersC 944/C 944M 99 (2005)e13ASTM International takes no pos
31、ition 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 such rights, are entirely their own responsibil
32、ity.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 additional standardsand should be addressed to AS
33、TM 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 shouldmake your views known to the ASTM Committee on Standards, at the address
34、 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).FIG. 3 Design Details of Rotating-Cutter Drill PressC 944/C 944M 99 (2005)e14
