ASTM_C_496_-_C_496M_-_11.pdf

Designation:C496/C496M11Standard Test Method forSplitting Tensile Strength of Cylindrical ConcreteSpecimens1This standard is issued under the fixed designation C496/C496M;the number immediately following the designation indicates the yearof original 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.Scope*1.1 This test method covers the determination of the split-ting tensile strength of cylindrical concrete specimens,such asmolded cylinders and drilled cores.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated 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 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.1.4 The text of this standard references notes that provideexplanatory material.These notes shall not be considered asrequirements of the standard.2.Referenced Documents2.1 ASTM Standards:2C31/C31M Practice for Making and Curing Concrete TestSpecimens in the FieldC39/C39M Test Method for Compressive Strength of Cylin-drical Concrete SpecimensC42/C42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of ConcreteC192/C192M Practice for Making and Curing Concrete TestSpecimens in the LaboratoryC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Materials3.Summary of Test Method3.1 This test method consists of applying a diametralcompressive force along the length of a cylindrical concretespecimen at a rate that is within a prescribed range until failureoccurs.This loading induces tensile stresses on the planecontaining the applied load and relatively high compressivestresses in the area immediately around the applied load.Tensile failure occurs rather than compressive failure becausethe areas of load application are in a state of triaxialcompression,thereby allowing them to withstand much highercompressive stresses than would be indicated by a uniaxialcompressive strength test result.3.2 Thin,plywood bearing strips are used to distribute theload applied along the length of the cylinder.3.3 The maximum load sustained by the specimen is dividedby appropriate geometrical factors to obtain the splitting tensilestrength.4.Significance and Use4.1 Splitting tensile strength is generally greater than directtensile strength and lower than flexural strength(modulus ofrupture).4.2 Splitting tensile strength is used in the design ofstructural lightweight concrete members to evaluate the shearresistance provided by concrete and to determine the develop-ment length of reinforcement.5.Apparatus5.1 Testing MachineThe testing machine shall conform tothe requirements of Test Method C39/C39M and be of a typewith sufficient capacity that will provide the rate of loadingprescribed in 7.5.5.2 Supplementary Bearing Bar or PlateIf the diameter orthe largest dimension of the upper bearing face or the lowerbearing block is less than the length of the cylinder to be tested,a supplementary bearing bar or plate of machined steel shall beused.The surfaces of the bar or plate shall be machined towithin 6 0.025 mm 6 0.001 in.of planeness,as measured onany line of contact of the bearing area.It shall have a width ofat least 50 mm 2 in.,and a thickness not less than the distancefrom the edge of the spherical or rectangular bearing block to1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregatesand is the direct responsibility of SubcommitteeC09.61 on Testing for Strength.Current edition approved July 1,2011.Published August 2011.Originallyapproved in 1962.Last previous edition approved in 2004 as C496041.DOI:10.1520/C0496_C0496M-11.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 the end of the cylinder.The bar or plate shall be used in suchmanner that the load will be applied over the entire length ofthe specimen.5.3 Bearing StripsTwo bearing strips of nominal 3.0 mm18in.thick plywood,free of imperfections,approximately 25mm 1 in.wide,and of a length equal to,or slightly longerthan,that of the specimen shall be provided for each specimen.The bearing strips shall be placed between the specimen a