ASTM_C_39_C39M-20.pdf

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.Designation:C39/C39M-20NTERNATIONALStandard Test Method forCompressive Strength of Cylindrical Concrete Specimens1This standard is issued under the fixed designation C39/C39M;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(e)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*2.Referenced Documents1.1 This test method covers determination of compressive2.1 ASTM Standards:2strength of cylindrical concrete specimens such as moldedC31/C31M Practice for Making and Curing Concrete Testcylinders and drilled cores.It is limited to concrete having aSpecimens in the Fielddensity in excess of 800 kg/m50 lb/ft.C42/C42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of Concrete1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The inch-pound unitsC125 Terminology Relating to Concrete and Concrete Ag-gregatesare shown in brackets.The values stated in each system maynot be exact equivalents;therefore,each system shall be usedC192/C192M Practice for Making and Curing Concrete TestSpecimens in the Laboratoryindependently of the other.Combining values from the twoC617/C617M Practice for Capping Cylindrical Concretesystems may result in non-conformance with the standard.Specimens1.3 This standard does not purport to address all of theC670 Practice for Preparing Precision and Bias Statementssafety concerns,if any,associated with its use.It is thefor Test Methods for Construction Materialsresponsibility of the user of this standard to establish appro-C873/C873M Test Method for Compressive Strength ofpriate safety,health,and environmental practices and deter-Concrete Cylinders Cast in Place in Cylindrical Moldsmine the applicability of regulatory limitations prior toC943 Practice for Making Test Cylinders and Prisms foruse.(Warning-Means should be provided to contain concreteDetermining Strength and Density of Preplaced-fragments during sudden rupture of specimens.Tendency forAggregate Concrete in the Laboratorysudden rupture increases with increasing concrete strength andC1077 Practice for Agencies Testing Concrete and Concreteit is more likely when the testing machine is relatively flexibleAggregates for Use in Construction and Criteria forThe safety precautions given in R0030 are recommended.)Testing Agency Evaluation1.4 The text of this standard references notes which provideC1176/C1176M Practice for Making Roller-Compactedexplanatory material.These notes shall not be considered asConcrete in Cylinder Molds Using a Vibrating Tablerequirements of the standard.C1231/C1231M Practice for Use of Unbonded Caps in1.5 This international standard was developed in accor-Determination of Compressive Strength of Hardened Cy-dance with internationally recognized principles on standard-lindrical Concrete Specimensization established in the Decision on Principles for theC1435/C1435M Practice for Molding Roller-CompactedDevelopment of International Standards,Guides and Recom-Concrete in Cylinder Molds Using a Vibrating Hammermendations issued by the World Trade Organization TechnicalC1604/C1604M Test Method for Obtaining and TestingBarriers to Trade(TBT)Committee.Drilled Cores of ShotcreteE4 Practices for Force Verification of Testing MachinesE18 Test Methods for Rockwell Hardness of Metallic Ma-terialsThis 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.2 For referenced ASTM standards,visit the ASTM website,www.astm.org,orCurrent edition approved Feb.1,2020.Published March 2020.Originallycontact ASTM Customer Service at serviceastm.org.For Annual Book of A.STMapproved in 1921.Last previous edition approved in 2018 as C39/C39M-18.DOI:Standards volume information,refer to the standards Document Summary page on10.1520/C0039C0039M-20.the 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 StatesCopyright by ASTM Intl(all rights reserved):Tue Mar 1705:52:54 EDT2020Downloaded/printed byTongji University(Tongji University)pursuant to License Agreement.No further reproductions authorized.C39/C39M-20E74 Practices for Calibration and Verification for Force-C943.C1176/C1176M.C1231/C1231M,andC1435/C1435MMeasuring Instrumentsand Test Methods C42/C42M.C873/C873M,and C1604/R0030 Manual of Aggregate and Concrete TestingC1604M5.3 The results of this test method are used as a basis for3.Terminologyquality control of concrete proportioning.mixing,and placing3.1 Definitions-For definitions of terms used in thisoperations;determination of compliance with specifications;practice,refer to Terminology C125.control for evaluating effectiveness of admixtures;and similar3.2 Definitions of Terms Specific to This Standard:uses.3.2.1 bearing block,n-steel piece to distribute the load5.4 The individual who tests concrete cylinders for accep-from the testing machine to the specimen.tance testing shall meet the concrete laboratory technician3.2.2 lower bearing block,n-steel piece placed under therequirements of Practice C1077,including an examinationspecimen to distribute the load from the testing machine to therequiring performance demonstration that is evaluated by anspecimen.independent examiner.3.2.2.1 Discussion-The lower bearing block provides aNorE 1-Certification equivalent to the minimum guidelines for AClreadily machinable surface for maintaining the specified bear-Concrete Laboratory Technician,Level I or ACI Concrete Strengthing surface.The lower bearing block may also be used to adaptTesting Technician will satisfy this requirementthe testing machine to various specimen heights.The lowerbearing block is also referred to as bottom block,plain block.6.Apparatusand false platen.6.1 Testing Machine-The testing machine shall be of a type3.2.3 platen,n-primary bearing surface of the testinghaving sufficient capacity and capable of providing the rates ofmachine.loading prescribed in 8.5.3.2.3.1 Discussion-The platen is also referred to as the6.1.1 Verify the accuracy of the testing machine in accor-testing machine table.dance with Practices E4,except that the verified loading range3.2.4 spacer;n-steel piece used to elevate the lower bear-shall be as required in 6.4.Verification is required:ing block to accommodate test specimens of various heights.6.1.1.1 Within 13 months of the last calibration3.2.4.1 Discussion-Spacers are not required to have hard-6.1.1.2 On original installation or immediately afterened bearing faces because spacers are not in direct contactrelocation.with the specimen or the retainers of unbonded caps.6.1.1.3 Immediately after making repairs or adjustments3.2.5 upper bearing block,n-steel assembly suspendedthat affect the operation of the force applying system or thevalues displayed on the load indicating system,except for zeroabove the specimen that is capable of tilting to bear uniformlyon the top of the specimen.adjustments that compensate for the mass of bearing blocks orspecimen,or both,or3.2.5.1 Discussion-The upper bearing block is also re-ferred to as the spherically seated block and the suspended6.1.1.4 Whenever there is reason to suspect the accuracy ofthe indicated loads.block.6.1.2 Design-The design of the machine must include the4.Summary of Test Methodfollowing features:6.1.2.1 The machine must be power operated and must4.1 This test method consists of applying a compressiveapply the load continuously rather than intermittently,andaxial load to molded cylinders or cores at a rate which is withinwithout shock.If it has only one loading rate(meeting thea prescribed range until failure occurs.The compressiverequirements of 8.5).it must be provided with a supplementalstrength of the specimen is calculated by dividing the maxi-means for loading at a rate suitable for verification.Thismum load attained during the test by the cross-sectional area ofsupplemental means of loading may be power or hand oper-the specimen.ated6.1.2.2 The space provided for test specimens shall be large5.Significance and Useenough to accommodate,in a readable position,an elastic5.1 Care must be exercised in the interpretation of thecalibration device which is of sufficient capacity to cover thesignificance of compressive strength determinations by this testpotential loading range of the testing machine and whichmethod since strength is not a fundamental or intrinsic propertycomplies with the requirements of Practice E74of concrete made from given materials.Values obtained willNorE 2-The types of elastic calibration devices most generallydepend on the size and shape of the specimen,batching,mixingavailable and most commonly used for this purpose are the circularprocedures,the methods of sampling,molding,and fabricationproving ring or load cell.and the age,temperature,and moisture conditions during6.1.3 Accuracy-The accuracy of the testing machine shallcuring.be in accordance with the following provisions:5.2 This test method is used to determine compressive6.1.3.1 The percentage of error for the loads within thestrength of cylindrical specimens prepared and cured in accor-proposed range of use of the testing machine shall not exceeddance with Practices C31/C31M,C192/C192M,C617/C617M.+1.0 of the indicated load.Copyright by ASTM Intl(all rights reserved):Tue Mar 1705:52:54 EDT 2020 2Downloaded/printed byTongji University(Tongji University)pursuant to License Agreement.No further reproductions authorized.C39/C39M-206.1.3.2 The accuracy of the testing machine shall be verified6.2 Bearing Blocks-The upper and lower bearing blocksby applying five test loads in four approximately equalshall conform to the following requirements:increments in ascending order.The difference between any two6.2.1 Bearing blocks shall be steel with hardened bearingsuccessive test loads shall not exceed one third of the differ-faces(Note 3).ence between the maximum and minimum test loads.6.2.2 Bearing faces shall have dimensions at least 3%6.1.3.3 The test load as indicated by the testing machine andgreater than the nominal diameter of the specimen.the applied load computed from the readings of the verification6.2.3 Except for the inscribed concentric circles describeddevice shall be recorded at each test point.Calculate the error,in 6.2.4.7,the bearing faces shall not depart from a plane byE,and the percentage of error,Ep.for each point from thesemore than 0.02 mm 0.001 in.along any 150 mm 6 in.lengthdata as follows:for bearing blocks with a diameter of 150 mm 6 in.or larger.E=A-B(1)or by more than 0.02 mm 0.001 in.in any direction of smallerbearing blocks.New bearing blocks shall be manufacturedE.=100(A-B)/Bwithin one half of this tolerance.where:NorE 3-It is desirable that the bearing faces of bearing blocks have aA load,kN Ibf indicated by the machine being verified,Rockwell hardness at least 55 HRC as determined by Test Methods E18.andNorE 4-Square bearing faces are permissible for the bearing blocks.B applied load,kN lbfas determined by the calibrating6.2.4 Upper Bearing Block-The upper bearing block shalldevice.conform to the following requirements:6.1.3.4 The report on the verification of a testing machine6.2.4.1 The upper bearing block shall be spherically seatedshall state within what loading range it was found to conformand the center of the sphere shall coincide with the center of theto specification requirements rather than reporting a blanketbearing face within 5 of the radius of the sphere.acceptance or rejection.In no case shall the loading range be6.2.4.2 The ball and the socket shall be designed so that thestated as including loads below the value which is 100 timessteel in the contact area does not permanently deform whenthe smallest change of load estimable on the load-indicatingloaded to the capacity of the testing machine.mechanism of the testing machine or loads within that portionof the range below 10 of the maximum range capacity.NorE 5-The preferred contact area is in the form of a ring(described6.1.3.5 In no case shall the loading range be stated asas preferred bearing area)as shown in Fig.I.including loads outside the range of loads applied during the6.2.4.3 Provision shall be made for holding the upperverification test.bearing block in the socket.The design shall be such that the6.1.3.6 The indicated load of a testing machine shall not bebearing face can be rotated and tilted at least 4 in anycorrected either by calculation or by the use of a calibrationdirection.diagram to obtain values within the required permissible6.2.4.4 If the upper bearing block is a two-piece designvariationcomposed of a spherical portion and a bearing plate,amechanical means shall be provided to ensure that the sphericalportion is fixed and centered on the bearing plate.6.2.4.5 The diameter of the sphere shall be at least 75 ofthe nominal diameter of the specimen.If the diameter of thesphere is smaller than the diameter of the specimen,the portionPREFERREDof the bearing face extending beyond the sphere shall have aBEARINGAREAthickness not less than the difference between the radius of thesphere and radius of the specimen(see Fig.1).The leastdimension of the bearing face shall be at least as great as thediameter of the sphere.6.2.4.6 The dimensions of the bearing face of the upperbearing block shall not exceed the following values:Nominal Diameter Maximum DiameterMaximum Dimensionsof Specimen,of Round Bearingof Square Bearingmm lin.IFace,mmn.】Face,mm in.50210541105by1054by4753)130151130by1305by5)TEST SPECIMEN10041656.5165by1656.5by6.5)1506)255101255by25510by10200828011)280by28011by11TR-r6.2.4.7 If the diameter of the bearing face of the upperr radius of spherical portion of upper bearing blockbearing block exceeds the nominal diameter of the specimen byR nominal radius of specimenmore than 13 mm 0.5 in.,concentric circles not more than 0.8T=thickness of upper bearing block extending beyond themm 0.03 in.deep and not more than 1 mm 0.04 in.widesphereshall be inscribed on the face of upper bearing block toFIG.1 Schematic Sketch of Typical Upper Bearing Blockfacilitate proper centering.Copyright by ASTM Intl(all rights reserved):Tue Mar 1705:52:54 EDT20203Downloaded/printed byTongji University(Tongji University)pursuant to License Agreement.No further reproductions authorized.4C39/C39M-20(specimen dimension method)or 7.4.2(submerged weighingwill vary depending on the machine manufacturer.Consult your ownersmethod).For either method,use a balance or scale that ismanual or compression machine calibrator for the proper technique.accurate to within 0.3 of the mass being measured.8.4.2 Verification of Alignment When Using Unbonded7.4.1 Remove any surface moisture with a towel and mea-Caps-If using unbonded caps,verify the alignment of thesure the mass of the specimen.Measure the length of thespecimen after application of load,but before reaching 10%ofspecimen to the nearest 1 mm 0.05 in.at three locationsthe anticipated specimen strength.Check to see that the axis ofspaced evenly around the circumference.Compute the averagethe cylinder does not depart from vertical by more than 0.5ength and record to the nearest 1 mm 0.05 in.(Note 13)and that the ends of the cylinder are centered within7.4.2 Remove any surface moisture with a towel and deter-the retaining rings.If the cylinder alignment does not meetmine the mass of the specimen in air.Submerge the specimenthese requirements,release the load,and carefully recenter thein water at a temperature of 23.0+2.0C 73.5 3.5Fforspecimen.Reapply load and recheck specimen centering and155 sec.Then,determine the apparent mass of the specimenalignment.A pause in load application to check cylinderwhile submerged under water.alignment is permissible.7.5 When density determination is not required and theNorE 13-An angle of 0.5 is equal to a slope of approximately 1 mmlength to diameter ratio is less than 1.8 or more than 2.2,in 100 mm inches in 12 inchesmeasure the length of the specimen to the nearest 0.05 D.8.5 Rate of Loading-Apply the load continuously and8.Procedurewithout shock.8.5.1 The load shall be applied at a rate of movement(platen8.1 Compression tests of moist-cured specimens shall beto crosshead measurement)corresponding to a stress rate onmade as soon as practicable after removal from moist storage.the specimen of 0.25 0.05 MPa/s 35 7 psi/s(see Note8.2 Test specimens shall be kept moist by any convenient14).The designated rate of movement shall be maintained atmethod during the period between removal from moist storageleast during the latter half of the anticipated loading phase.and testing.They shall be tested in the moist conditionNorE 14-For a screw-driven or displacement-controlled testing8.3 Tolerances for specimen ages are as follows:machine,preliminary testing will be necessary to establish the requiredTest AgeAPermissible Tolerancerate of movement to achieve the specified stress rate.The required rate of24h0.5hmovement will depend on the size of the test specimen,the elastic3 days2hmodulus of the concrete,and the stiffness of the testing machine7 days6h28 days20h8.5.2 During application of the first half of the anticipated90 days2daysloading phase,a higher rate of loading shall be permitted.Thehigher loading rate shall be applied in a controlled manner soAFor test ages not listed,the test age tolerance is 2.0%of the specified agethat the specimen is not subjected to shock loading.8.3.1 Unless otherwise specified by the specifier of tests,for8.5.3 Make no adjustment in the rate of movement(platen tothis test method the test age shall start at the beginning ofcrosshead)as the ultimate load is being approached and thecasting specimens.stress rate decreases due to cracking in the specimen.8.4 Placing the Specimen-Place the lower bearing block.8.6 Apply the compressive load until the load indicatorwith the hardened face up,on the table or platen of the testingshows that the load is decreasing steadily and the specimenmachine.Wipe clean the bearing faces of the upper and lowerdisplays a well-defined fracture pattern(Types 1 to 4 in Fig.2).bearing blocks,spacers if used,and of the specimen.If usingFor a testing machine equipped with a specimen break detector,unbonded caps,wipe clean the bearing surfaces of the retainersautomatic shut-off of the testing machine is prohibited until theand center the unbonded caps on the specimen.Place theload has dropped to a value that is less than 95 of the peakspecimen on the lower bearing block and align the axis of theload.When testing with unbonded caps,a corner fracturespecimen with the center of thrust of the upper bearing block.similar to a Type 5 or 6 pattern shown in Fig.2 may occurbefore the ultimate capacity of the specimen has been attained.NorE 11-Although the lower bearing block may have inscribedContinue compressing the specimen until the user is certainconcentric circles to assist with centering the specimen.final alignment ismade with reference to the upper bearing blockthat the ultimate capacity has been attained.Record themaximum load carried by the specimen during the test,and8.4.1 Zero Verification and Block Seating-Prior to testingnote the type of fracture pattern according to Fig.2.If thethe specimen,verify that the load indicator is set to zero.Infracture pattern is not one of the typical patterns shown in Fig.cases where the indicator is not properly set to zero,adjust theindicator(Note 12).After placing the specimen in the machine2,sketch and describe briefly the fracture pattern.If thebut prior to applying the load on the specimen,tilt the movablemeasured strength is lower than expected,examine the frac-tured concrete and note the presence of large air voidsportion of the spherically seated block gently by hand so thatthe bearing face appears to be parallel to the top of the testevidence of segregation,whether fractures pass predominantlyspecimen.around or through the coarse aggregate particles,and verifyend preparations were in accordance with Practice C617/NorE 12-The technique used to verify and adjust load indicator to zeroC617M or Practice C1231/C1231M.Copyright by ASTM Intl(all rights reserved):Tue Mar 1705:52:54 EDT 2020 5Downloaded/printed byTongji University(Tongji University)pursuant to License Agreement.No further reproductions authorized.