1、Designation: C418 12Standard Test Method forAbrasion Resistance of Concrete by Sandblasting1This standard is issued under the fixed designation C418; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb
2、er 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 This test method covers determination of the abrasionresi
3、stance characteristics of concrete by subjecting it to theimpingement of air-driven silica sand. It is intended for use asa basis for the development of informed judgment.1.2 The values stated in SI units are to be regarded as thestandard. Inch-pound units are shown for information purposesin parent
4、heses.1.3 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.NOTE 1Users of this
5、test method are advised that there are knownsafety hazards associated with the use of silica as a blasting media.Consult the silica manufactures MSDS to insure that the latest recom-mended health and safety practices are being followed.NOTE 2Other procedures are available for measuring abrasion resi
6、s-tance of concrete surfaces in addition to subjecting it to air driven silicasand. Consideration should be given to other methods of testing asoutlined in ASTM C779/C779M, ASTM C944, and ASTM C1138. Thetest method most closely representing service conditions should be used.1.4 The text of this stan
7、dard references notes and footnoteswhich are provided as explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beconsidered as requirements of this standard.2. Referenced Documents2.1 ASTM Standards:2C125 Terminology Relating to Concrete and Concrete Ag-gre
8、gatesC127 Test Method for Density, Relative Density (SpecificGravity), and Absorption of Coarse AggregateC778 Specification for SandC779/C779M Test Method for Abrasion Resistance of Hori-zontal Concrete SurfacesC944 Test Method for Abrasion Resistance of Concrete orMortar Surfaces by the Rotating-Cu
9、tter MethodC1138 Test Method for Abrasion Resistance of Concrete(Underwater Method)3. Terminology3.1 For definitions of terms used in this standard, refer toTerminology C125.4. Significance and Use4.1 This test method covers the laboratory evaluation of therelative resistance of concrete surfaces to
10、 abrasion. Thisprocedure simulates the action of waterborne abrasives andabrasives under traffic on concrete surfaces. It performs acutting action that tends to abrade more severely the lessresistant components of the concrete.5. Apparatus5.1 ScalesThe scale shall have a capacity of 5000 g ormore. T
11、he permissible variation at a load of 5000 g (11 lb) shallbe 6 0.5 g (0.2 oz).5.2 WeightsThe permissible variations on weights used inweighing shall be as prescribed in Table 1. The permissiblevariations on new weights shall be one half of the values givenin Table 1.5.3 Sand Blast ApparatusThe sand
12、blast apparatus shallconsist of an injector-type gun. The gun shall have a high-velocity air jet fed by a suitably controlled rate of flow for theabrasive material. The nozzle shown in Fig. 1 shall consist ofcold-rolled bar stock, 40 mm (1.5 in.) long, or hardened toolsteel HRC 48 6 2 as determined
13、by Test Methods E18, drilledto 6.40 6 0.02 mm (0.250 6 0.001 in.) approximately 700 kPa(100 psi) through the center. The walls of the nozzle shall havea 45 bevel on the inside at the upper end. A compressed airsupply of approximately 100 psi (690 kPa) shall be availableand equipped with a pressure-c
14、ontrol device. Provision shall bemade to collect the spent abrasive and dust. Suitable jigs andclamps shall be provided to hold the test specimen in a fixedposition with relation to the discharge end of the nozzle. For1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and C
15、oncrete Aggregatesand is the direct responsibility of SubcommitteeC09.62 on Abrasion Testing.Current edition approved Dec. 1, 2012. Published January 2013. Originallyapproved in 1958. Last previous edition approved in 2005 as C418 05. DOI:10.1520/C0418-12.2For referenced ASTM standards, visit the AS
16、TM 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 Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr H
17、arbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1laboratory wear testing of concrete specimens a commercialsand blast cabinet may be selected similar to that shown in Fig.2.5.4 ShieldThe shield shall be square or circular, 150 mm(6 in.) on a side or diameter, made from zinc-
18、coated steel sheetor equivalent, having a thickness in the range of 0.90 to 1.90mm (0.035 to 0.075 in.). The shield shall have an opening28.70 6 0.25 mm (1.13 6 0.01 in.) in diameter in the center(See Note 3).NOTE 3An opening of 28.7 mm (1.13 in.) is equivalent to 6.45 cm2(1in.2). The purpose of the
19、 opening in the shield is to limit the abraded areato approximately 1 in.25.5 AbrasiveThe abrasive shall conform to SpecificationC778 for 2030 sand (predominantly graded to pass an 850-m(No. 20) sieve and be retained on a 600-m (No. 30) sieve).6. Preparation of Specimens6.1 Immerse the specimens in
20、water for 24 h and thensurface dry with a damp cloth to obtain a saturated, surface-drycondition at the time of test.7. Calibration of Apparatus7.1 Adjust the air pressure to 410 6 1 kPa (59.5 6 1 psi)and collect the abrasive for a period of 1 min. Adjust the rateof flow of abrasive to 600 6 25 g/mi
21、n (See Note 4).NOTE 4Aball valve between the abrasive supply and the gun inlet hasbeen found satisfactory for adjusting the flow of abrasive.7.2 The abrasive shall be regraded or replaced after every 60min of operating time in order to maintain a uniform grading.7.3 Acold-rolled steel nozzle shall b
22、e replaced every 60 minof operating time. A hardened tool steel nozzle shall bechanged as required to maintain the original uniform flow andoriginal blast pattern.8. Procedure8.1 Place the specimen with the surface to be tested normalto the nozzle axis and at a distance of 75 6 2.5 mm (3.0 6 0.1in.)
23、 from the end. Clamp the specimen, with shield attached,firmly in place. Expose the surface to the blast for a period of1 min. Repeat this on at least eight different spots on theTABLE 1 Permissible Variations on WeightsWeight, gPermissible Variations onWeights in Use, g1000 0.50500 0.35300 0.30250
24、0.25200 0.20NOTE 1All dimensions are approximate except where tolerances areshown. Inch-pound dimensions shown here for clarity purposes only.FIG. 1 Gun Nozzle AssemblyFIG. 2 Sand Blast CabinetC418 122surface. Determine the abraded volume by filling the abrasioncavities with an oil base modeling cla
25、y. Press the clay into thecavities manually with a moderate amount of finger pressureand level flush with a straight edge. Determine the mass of theclay supply before and after the cavities are filled to thetolerance listed in Table 1 instead of removing the clay fromthe filled cavities. Repeat fill
26、ing with clay at least once on eachspecimen to ensure reproducible results.9. Calculation9.1 Calculate the mass of clay, Wc, as follows:Wc5 Wi2 Wfwhere:Wi= mass, initial supply, andWf= mass, final supply.9.2 Calculate the specific gravity of clay, D, as follows:D 5 B/B 2 C!where:B = mass of clay in
27、air, g, andC = mass of clay in water, g.NOTE 5Appendix X1 of Test Method C127 provides guidance on thedevelopment of the equations used in the calculation of specific gravity(relative density to water) using the mass of clay in air and the mass ofclay when suspended in water.9.3 Calculate the volume
28、 of clay, V, per cavity in cubiccentimetres, as follows:V 5 W/Dwhere:W = mass of clay in cavity, andD = specific gravity of clay.9.4 Calculate the abrasion coefficient loss on a volumetricbasis, expressed in cubic centimetres per square centimetre, inorder to compensate for variable densities of spe
29、cimens, asfollows:Ac5 V/Awhere:Ac= abrasion coefficient, cubic centimetres per squarecentimetre, andA = area of surface abraded, square centimetres.10. Report10.1 Report the following information:10.2 Report the abrasion coefficient loss to the nearest 0.01cm3/cm2.10.3 Report the location of the con
30、crete where the specimenwas obtained and other characteristics of the concrete, ifknown.11. Precision and Bias11.1 On a limited sampling (Note 6), the single-operatorcoefficient of variation has been found to be 9.1 %.3Therefore,results of two properly conducted tests by the same operator onthe same
31、 material using the same equipment should not differby more than 25.8 %3of their average.11.2 On a limited sampling (Note 6), the multi-operatorcoefficient of variation has been found to be 10.3 %.3Therefore, results of two properly conducted tests by twooperators on the same material using the same
32、 equipmentshould not differ from each other by more than 29.1 %3of theiraverage.NOTE 6The data, on file at ASTM Headquarters, involve twooperators performing the tests on samples made from the same batch andrepeated on another day. Two concrete mixtures having different expectedabrasion resistance w
33、ere also used. The tests were conducted in onelaboratory using the same equipment. As more laboratories become moreequipped and capable of performing the test, a more detailed interlabora-tory test program will be conducted.11.3 Since there is no acceptable reference material suitablefor determining
34、 bias for the procedure in this test method, nostatement of bias is being made.12. Keywords12.1 abrasion; concrete; density; sandblasting; wearSUMMARY OF CHANGESCommmittee C09 has identified the location of selected changes to this test method since the last issue,C41805, that may impact the use of
35、this test method. (Approved December 1, 2012)(1) Added new Section 3 Terminology, including reference toTerminology C125, and renumbered subsequent sections.(2) Added new Section 12 Keywords.3These numbers represent, respectively, the (1s %) and (d2s %) limits asdescribed in Practice C670 for Prepar
36、ing Precision and Bias Statements for TestMethods for Construction Materials.C418 123ASTM 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 th
37、e validity of any such patent rights, and the riskof infringement of such 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. You
38、r comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM 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
39、 have not received a fair hearing you shouldmake your views known to the 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 mult
40、iple 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/).C418 124
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