1、Designation:C293/C293M16Standard Test Method forFlexural Strength of Concrete(Using Simple Beam WithCenter-Point Loading)1This standard is issued under the fixed designation C293/C293M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,
2、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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 This test method covers
3、determination of the flexuralstrength of concrete specimens by the use of a simple beamwith center-point loading.Test Method C293/C293M is not analternative to Test Method C78/C78M.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated
4、 ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is t
5、heresponsibility 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:2C31/C31M Practice for Making and Curing Concrete TestSpecimens in the FieldC78/C78M Te
6、st Method for Flexural Strength of Concrete(Using Simple Beam with Third-Point Loading)C192/C192M Practice for Making and Curing Concrete TestSpecimens in the LaboratoryC617/C617M Practice for Capping Cylindrical ConcreteSpecimensC1077 Practice for Agencies Testing Concrete and ConcreteAggregates fo
7、r Use in Construction and Criteria forTesting Agency EvaluationE4 Practices for Force Verification of Testing Machines2.2 TXDOT Standard:3TEX-420-A Test Method for Flexural Strength of ConcreteUsing Simple Beam with Center-Point Loading3.Significance and Use3.1 This test method is used to determine
8、the modulus ofrupture of specimens prepared and cured in accordance withPractices C31/C31M or C192/C192M.The strength deter-mined will vary where there are differences in specimen size,preparation,moisture condition,or curing.3.2 The results of this test method may be used to determinecompliance wit
9、h specifications or as a basis for proportioning,mixing and placement operations.This test method producesvalues of flexural strength significantly higher than TestMethod C78/C78M.4.Apparatus4.1 Testing MachineThe testing machine shall conform tothe requirements of the sections on Basis of Verificat
10、ion,Corrections,and Time Interval Between Verifications of Prac-tices E4.Hand operated testing machines having pumps that donot provide a continuous loading to failure in one stroke are notpermitted.Motorized pumps or hand operated positive dis-placement pumps having sufficient volume in one continu
11、ousstroke to complete a test without requiring replenishment arepermitted and shall be capable of applying loads at a uniformrate without shock or interruption.The testing machine shall beequipped with a means of recording or holding the peak valuethat will indicate the maximum load applied to the s
12、pecimenduring a test,to within 1%accuracy of the load being applied.4.2 Loading ApparatusThe mechanism by which forcesare applied to the specimen shall employ a load-applying blockand two specimen support blocks.It shall ensure that all forcesare applied perpendicular to the face of the specimen wit
13、houteccentricity.A diagram of an apparatus that accomplishes thispurpose is shown in Fig.1.1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.61 on Testing for Strength.Current edition approved Apri
14、l 15,2016.Published June 2016.Originallyapproved in 1952.Last previous edition approved in 2015 as C293/C293M 15.DOI:10.1520/C0293_C0293M-16.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume i
15、nformation,refer to the standards Document Summary page onthe ASTM website.3Manual of Testing Procedures,Texas State Department of Highways and PublicTransportation,1986.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,We
16、st Conshohocken,PA 19428-2959.United States1 4.2.1 All apparatus for making center-point loading flexuretests shall be similar to Fig.1 and maintain the span length andcentral position of the load-applying block with respect to thesupport blocks constant within 61.0 mm 60.05 in.4.2.2 Reactions shall be parallel to the direction of theapplied load at all times during the test,and the ratio of thehorizontal distance between the point of load application andnearest reaction to the depth of the beam
