1、Designation: C944/C944M 99 (Reapproved 2005)1 C944/C944M 12Standard Test Method forAbrasion Resistance of Concrete or Mortar Surfaces by theRotating-Cutter Method1This standard is issued under the fixed designation C944/C944M; 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.1 NOTEThe designation was changed editorially to agree with the existing v
3、alues statement in the Scope in March2008.1. Scope Scope*1.1 This test method covers a procedure for determining the resistance of either concrete or mortar to abrasion. This test methodis similar to Procedure B of Test Method C779/C779M.1.2 The values stated in SI units or inchpound units are to be
4、 regarded separately as standard. The values stated in each systemmay not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the twosystems may result in nonconformance with the standard.1.3 This standard does not purport to address all of th
5、e safety concerns, if any, associated with its use. It is 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:2C42/C42M Test Method for Obta
6、ining and Testing Drilled Cores and Sawed Beams of ConcreteC125 Terminology Relating to Concrete and Concrete AggregatesC418 Test Method for Abrasion Resistance of Concrete by SandblastingC779/C779M Test Method for Abrasion Resistance of Horizontal Concrete Surfaces3. Terminology3.1 For definitions
7、of terms used in this standard, refer to Terminology C125.4. Significance and Use4.1 This test method gives an indication of the relative wear resistance of mortar and concrete based on testing of cored orfabricated specimens. This test method has been successfully used in the quality control of hig
8、hway and bridge concrete subjectto traffic. Primarily intended for use on the top ends of 152-mm 6-in. diameter concrete cores, mortar specimens, or other samplesof concrete of insufficient test area to permit the conduct of tests by Test Method C418 or C779/C779M, this test method is alsoapplicable
9、 on concrete surfaces in place by measuring the abrasion loss as described in Section 910, Procedure B, of Test MethodC779/C779M.5. Apparatus5.1 Abrasion DeviceA drill press or similar device with a chuck capable of holding and rotating the abrading cutter at a speedof 200 r/min and exerting a force
10、 of either a normal load of 98 6 1 N 22 6 0.2 lbf or a double load of 197 6 2 N 44 6 0.4lbf on the test specimen surface. Fig. 1 shows a commercial drill press and Fig. 2 illustrates details of the rotating cutter. Thedifficulty in maintaining a constant load on the abrading cutter when using the le
11、ver, gear, and spring system of a drill press has1 This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregatesand is the direct responsibility of Subcommittee C09.62 onAbrasion Testing.Current edition approved May 1, 2005Dec. 1, 2012. Published June 2005Decem
12、ber 2012. Originally approved in 1980. Last previous edition approved in 19902005 asC944 90a.C944 99(2005)1. DOI: 10.1520/C0944_C0944M-99R05E01.10.1520/C0944_C0944M-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annu
13、al Book of ASTM Standardsvolume information, refer to the standards Document 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
14、technically possible to adequately depict all changes accurately, ASTM recommends 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
15、this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1been eliminated by placing the desired load directly upon the spindle that turns the cutter. The machine consists essentially of aframe that supports the drive motor, steppe
16、d pulley, and spindle. A clamping device to hold the specimen is built into the base.5.2 Rotating CutterA rotating cutter similar to that shown in 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 to 1.25 in. diameter washers are mounted. T
17、he washers as received shallbe stacked and locked on a bolt for the purpose of reducing their diameter to the specified range to avoid restricting abrasion ofthe concrete by the washers. Cutter assembly, including washers, shall be locked onto horizontal rods such that individual dressingwheels are
18、free to turn independently. The overall diameter of the cutter or the diameter of the circular area abraded is 82.5 mm314 in. Care shall be taken to achieve constant contact between the rotating cutter and the entire test surface of the sample. Thiscan be better accomplished if the cutters have a sw
19、ivel connection allowing some vertical movement. If the dressing wheels haveone rounded edge, they shall be mounted with the rounded edge toward the vertical shaft. The individual grinding wheel dresserson the horizontal shaft of the cutter shall be repositioned whenever a change in the diameter of
20、the outer cutters becomes apparent.This is accomplished by reversing each set of dressing wheels to bring the smaller diameter cutters toward the vertical shaft.NOTE 1Dressing wheels, also known as “steel scarifier cutters,” with dimesions of 38.1 mm OD, 12.5 mm ID, 2.5 mm thick 1-12 in. OD, 12 in.
21、ID,332 in. thick and Plain Steel SAE 12 in. screw size, 1732 in. ID, 1-116 in. OD, 0.074 in. thick Flat Washers (no metric equivalent available) have beenfound suitable for this purpose.5.2.1 In making a test, the rotating cutter is held in a raised position by means of the rod provided, the specime
22、n clampedsecurely in position, and motor started. The rotating cutter is then lowered into contact with the specimen for a specified time, afterwhich the cutter is raised.FIG. 1 Rotating-Cutter Drill PressC944/C944M 1225.2.2 A set of dressing wheels shall be replaced periodically, preferably after e
23、ach 90 min of use. The washers may be groundor replaced to maintain the proper diameter.5.3 BalanceA balance having a capacity of at least 4 kg, and accurate to at least 0.1 g.5.4 Leveling PlateThe base plate upon which the specimen rests shall be capable of rotating in the horizontal plane so thatt
24、he specimens when placed thereon can be positioned to secure maximum contact with the rotating cutter throughout the full testarea.6. Sampling6.1 Cores shall be taken in accordance with Test Method C42/C42M.7. Specimens7.1 The specimens used in this test shall be of any size and shape that can be ac
25、commodated by the abrasion device and thebalance provided. The surface to be tested shall be either formed or finished and shall be positioned in the plane of contact of thecutter.8. Procedure8.1 Determine the mass of the specimen to the nearest 0.1 g.8.2 Fasten the specimens securely in the abrasio
26、n device so that the surface to be tested is normal to the shaft.8.3 Mount the rotating cutter device in the abrasion device.8.4 Start the motor and lower the cutter slowly until just in contact with the surface of the specimen.8.5 Continue abrasion with a normal or a double load on the specimen for
27、 2 min after contact between the cutter and the surface.At the end of each 2-min abrasion period, remove the test specimen from the device and clean surfaces to remove debris usinga soft brush or blow the surface with air. Determine the specimen mass to the nearest 0.1 g. The minimum test schedule s
28、hallinvolve three 2-min periods conducted on three separate areas of representative surfaces of the concrete or mortar.8.6 For concrete that is highly resistant to abrasion additional testing may be required. Doubling the applied load, or the time,or both, as shown in the following chart, should pro
29、vide more comprehensive information on such concrete.Abrasion Cycle Load, N (lbf) Test Frequency/PeriodA NormalB Double load98 (22)197 (44)3 2 min3 2 min8.7 When testing surfaces in place, or when the depth of wear is to be determined due to significant differences in surfacedensity, refer to Test M
30、ethod C779/C779M Procedure B, to determine abraded depth using the apparatus in this test method.FIG. 2 Typical Rotating CuttersC944/C944M 1239. Report9.1 Report the following information on:9.1.1 Description of surface,9.1.2 Size of specimen,9.1.3 Type of finish,9.1.4 Concrete compaction, age, and
31、strength,9.1.5 Applied surface treatment,9.1.6 Time of abrasion and load used (normal or double),9.1.7 Average loss in grams or depth of wear in millimetres and,9.1.8 Loss in mass and time abraded.10. Precision and Bias10.1 PrecisionCriteria for judging the acceptability of abrasion resistance test
32、results obtained by this test method are asfollows:FIG. 3 Design Details of Rotating-Cutter Drill PressC944/C944M 12410.1.1 Normal Load ConditionThe single-operator coefficient of variation has been found to be 21 %. Therefore, the resultsof two properly conducted tests by the same operator on simil
33、ar samples should not differ from each other by more than 59 % ofthe average.10.1.2 Double Load ConditionThe single-operator coefficient of variation has been found to be 12.6 %. Therefore, the resultsof two properly conducted tests by the same operator on similar samples should not differ from each
34、 other by more than 36 % oftheir average.10.2 BiasThe procedure in this test method has no bias because the value of abrasion resistance of concrete surfaces can beonly defined in terms of a test method.11. Keywords11.1 abrasion; concrete; impact; mortar; wearSUMMARY OF CHANGESCommittee C09 has iden
35、tified the location of selected changes to this test method since the last issue,C944 99(2005)1, that may impact the use of this test method. (Approved December 1, 2012)(1) Added new Section 3 Terminology, including reference to Terminology C125, and renumbered subsequent sections.(2) Added new Note
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39、ittee 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/).C944/C944M 125
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