ASTM_C_198_-_09_2013.pdf

Designation:C19809(Reapproved 2013)Standard Test Method forCold Bonding Strength of Refractory Mortar1This standard is issued under the fixed designation C198;the number immediately following the designation indicates the year oforiginal adoption or,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.1.Scope1.1 This test method covers the determination of the bond-ing strength of air-setting refractory mortar by determining theflexural strength(modulus of rupture)at room temperature ofoven-dried brick-mortar joints.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport 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.2.Referenced Documents2.1 ASTM Standards:2C78 Test Method for Flexural Strength of Concrete(UsingSimple Beam with Third-Point Loading)C133 Test Methods for Cold Crushing Strength and Modu-lus of Rupture of RefractoriesC651 Test Method for Flexural Strength of ManufacturedCarbon and GraphiteArticles Using Four-Point Loading atRoom TemperatureE4 Practices for Force Verification of Testing MachinesE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Significance and Use3.1 The data developed by this test method show thebonding strength and intrinsic strength of different qualities ofair-setting mortar.The procedures described in this test methodmeasure the bonding strength and intrinsic strength of air-setting mortars when used with specific brands or lots ofrefractory brick.3.2 Note that it is possible to obtain results with thesemethods for brick and mortar combinations which are incom-patible for use at high operating temperatures.The user mustdetermine this compatibility.Only brick and mortar combina-tions known or intended to be compatible for a particular useshould be tested.3.3 Properties of the brick,including its strength,apparentporosity,and pore size distribution,can affect the measurementof both the bonding strength of the brick-mortar composite andthe intrinsic strength of the mortar.The average modulus ofrupture of the test brick,as determined by Test Method C133,should exceed that expected for the mortar being tested.Thetesting of specific brands or lots of brick and mortar ispreferred.3.4 Three modes of failure are available:the break mayoccur within the brick itself,at the brick-mortar interface,orwithin the mortar itself.The latter provides a practical mea-surement of the strength of the mortar itself and is thepredominant mode of failure with the four-point flexure testdescribed.The three-point flexure test measures the failurestrength of the brick-mortar composite.Failure within the brickitself suggests that either the particular brick contained aserious flaw,or that the mortar joint strength is of the samemagnitude or greater than that of the refractory brick.Themode of failure should always be reported in the final report.3.5 A ruggedness test for this test method3performed in1985 found the following variables to be rugged:specimen size(2.5 to 3.0 in.),mortared surface(cut versus uncut),jointthickness(116to18in.),pulling of rods(fast versus slow),theloading rate(500 to 1000 lbf/min),the method of loadapplication(3-versus 4-point),and the operator.3.6 The cold bonding strengths of refractory mortars ob-tained by this test method are suitable for use in research anddevelopment,quality control,and for establishing and evalu-ating compliance with specifications between producers andconsumers.1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.01 on Strength.Current edition approved Sept.1,2013.Published September 2013.Originallyapproved in 1945.Last previous edition approved in 2009 as C198 09.DOI:10.1520/C0198-09R13.2For 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.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:C08-1008.ContactASTM CustomerService at serviceastm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Apparatus4.1 BrickAt least five 9 by 414by 212-in.(230 by 114 by65-mm)straight brick having plane surfaces and true rectan-gu