1、Designation: C39/C39M 18Standard 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 r
2、evision. A number 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 U.S. Department of Defense.1. Scope*1.1 This test method covers determination
3、 of compressivestrength of cylindrical concrete specimens such as moldedcylinders and drilled cores. It is limited to concrete having adensity in excess of 800 kg/m350 lb/ft3.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The inch-pound unitsar
4、e shown in brackets. The values stated in each system maynot be exact equivalents; therefore, each system shall be usedindependently of the other. Combining values from the twosystems may result in non-conformance with the standard.1.3 This standard does not purport to address all of thesafety conce
5、rns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior touse.(WarningMeans should be provided to contain concretefragments during
6、 sudden rupture of specimens. Tendency forsudden rupture increases with increasing concrete strength andit is more likely when the testing machine is relatively flexible.The safety precautions given in the Manual are recommended.)1.4 The text of this standard references notes which provideexplanator
7、y material. These notes shall not be considered asrequirements of the standard.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides a
8、nd Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C31/C31M Practice for Making and Curing Concrete TestSpecimens in the FieldC42/C42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of C
9、oncreteC125 Terminology Relating to Concrete and Concrete Ag-gregatesC192/C192M Practice for Making and Curing Concrete TestSpecimens in the LaboratoryC617/C617M Practice for Capping Cylindrical ConcreteSpecimensC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Constructi
10、on MaterialsC873/C873M Test Method for Compressive Strength ofConcrete Cylinders Cast in Place in Cylindrical MoldsC943 Practice for Making Test Cylinders and Prisms forDetermining Strength and Density of Preplaced-Aggregate Concrete in the LaboratoryC1077 Practice for Agencies Testing Concrete and
11、ConcreteAggregates for Use in Construction and Criteria forTesting Agency EvaluationC1176/C1176M Practice for Making Roller-CompactedConcrete in Cylinder Molds Using a Vibrating TableC1231/C1231M Practice for Use of Unbonded Caps inDetermination of Compressive Strength of Hardened Cy-lindrical Concr
12、ete SpecimensC1435/C1435M Practice for Molding Roller-CompactedConcrete in Cylinder Molds Using a Vibrating HammerC1604/C1604M Test Method for Obtaining and TestingDrilled Cores of ShotcreteE4 Practices for Force Verification of Testing MachinesE18 Test Methods for Rockwell Hardness of Metallic Ma-t
13、erials1This 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 Jan. 1, 2018. Published February 2018. Originallyapproved in 1921. Last previous edition
14、approved in 2017 as C39/C39M 17b.DOI: 10.1520/C0039_C0039M-18.2For 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
15、.*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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization est
16、ablished 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.1E74 Practice of Calibration of Force-Measuring Instrumentsfor Verifying the Force Indication of Testing
17、 MachinesManual of Aggregate and Concrete Testing3. Terminology3.1 DefinitionsFor definitions of terms used in thispractice, refer to Terminology C125.3.2 Definitions of Terms Specific to This Standard:3.2.1 bearing block, nsteel piece to distribute the loadfrom the testing machine to the specimen.3
18、.2.2 lower bearing block, nsteel piece placed under thespecimen to distribute the load from the testing machine to thespecimen.3.2.2.1 DiscussionThe lower bearing block provides areadily machinable surface for maintaining the specified bear-ing surface. The lower bearing block may also be used to ad
19、aptthe testing machine to various specimen heights. The lowerbearing block is also referred to as bottom block, plain block,and false platen.3.2.3 platen, nprimary bearing surface of the testingmachine.3.2.3.1 DiscussionThe platen is also referred to as thetesting machine table.3.2.4 spacer, nsteel
20、piece used to elevate the lower bear-ing block to accommodate test specimens of various heights.3.2.4.1 DiscussionSpacers are not required to have hard-ened bearing faces because spacers are not in direct contactwith the specimen or the retainers of unbonded caps.3.2.5 upper bearing block, nsteel as
21、sembly suspendedabove the specimen that is capable of tilting to bear uniformlyon the top of the specimen.3.2.5.1 DiscussionThe upper bearing block is also re-ferred to as the spherically seated block and the suspendedblock.4. Summary of Test Method4.1 This test method consists of applying a compres
22、siveaxial load to molded cylinders or cores at a rate which is withina prescribed range until failure occurs. The compressivestrength of the specimen is calculated by dividing the maxi-mum load attained during the test by the cross-sectional area ofthe specimen.5. Significance and Use5.1 Care must b
23、e exercised in the interpretation of thesignificance of compressive strength determinations by this testmethod since strength is not a fundamental or intrinsic propertyof concrete made from given materials. Values obtained willdepend on the size and shape of the specimen, batching, mixingprocedures,
24、 the methods of sampling, molding, and fabricationand the age, temperature, and moisture conditions duringcuring.5.2 This test method is used to determine compressivestrength of cylindrical specimens prepared and cured in accor-dance with Practices C31/C31M, C192/C192M, C617/C617M,C943, C1176/C1176M
25、, C1231/C1231M, and C1435/C1435M,and Test Methods C42/C42M, C873/C873M, and C1604/C1604M.5.3 The results of this test method are used as a basis forquality control of concrete proportioning, mixing, and placingoperations; determination of compliance with specifications;control for evaluating effecti
26、veness of admixtures; and similaruses.5.4 The individual who tests concrete cylinders for accep-tance testing shall meet the concrete laboratory technicianrequirements of Practice C1077, including an examinationrequiring performance demonstration that is evaluated by anindependent examiner.NOTE 1Cer
27、tification equivalent to the minimum guidelines for ACIConcrete Laboratory Technician, Level I or ACI Concrete StrengthTesting Technician will satisfy this requirement.6. Apparatus6.1 Testing MachineThe testing machine shall be of a typehaving sufficient capacity and capable of providing the rates o
28、floading prescribed in 8.5.6.1.1 Verify the accuracy of the testing machine in accor-dance with Practices E4, except that the verified loading rangeshall be as required in 6.4. Verification is required:6.1.1.1 Within 13 months of the last calibration,6.1.1.2 On original installation or immediately a
29、fterrelocation,6.1.1.3 Immediately after making repairs or adjustmentsthat affect the operation of the force applying system or thevalues displayed on the load indicating system, except for zeroadjustments that compensate for the mass of bearing blocks orspecimen, or both, or6.1.1.4 Whenever there i
30、s reason to suspect the accuracy ofthe indicated loads.6.1.2 DesignThe design of the machine must include thefollowing features:6.1.2.1 The machine must be power operated and mustapply the load continuously rather than intermittently, andwithout shock. If it has only one loading rate (meeting thereq
31、uirements of 8.5), it must be provided with a supplementalmeans for loading at a rate suitable for verification. Thissupplemental means of loading may be power or hand oper-ated.6.1.2.2 The space provided for test specimens shall be largeenough to accommodate, in a readable position, an elasticcalib
32、ration device which is of sufficient capacity to cover thepotential loading range of the testing machine and whichcomplies with the requirements of Practice E74.NOTE 2The types of elastic calibration devices most generallyavailable and most commonly used for this purpose are the circularproving ring
33、 or load cell.6.1.3 AccuracyThe accuracy of the testing machine shallbe in accordance with the following provisions:6.1.3.1 The percentage of error for the loads within theproposed range of use of the testing machine shall not exceed61.0 % of the indicated load.C39/C39M 1826.1.3.2 The accuracy of th
34、e testing machine shall be verifiedby applying five test loads in four approximately equalincrements in ascending order. The difference between any twosuccessive test loads shall not exceed one third of the differ-ence between the maximum and minimum test loads.6.1.3.3 The test load as indicated by
35、the testing machine andthe applied load computed from the readings of the verificationdevice shall be recorded at each test point. Calculate the error,E, and the percentage of error, Ep, for each point from thesedata as follows:E 5 A 2 B (1)Ep5 100A 2 B!/Bwhere:A = load, kN lbf indicated by the mach
36、ine being verified,andB = applied load, kN lbf as determined by the calibratingdevice.6.1.3.4 The report on the verification of a testing machineshall state within what loading range it was found to conformto specification requirements rather than reporting a blanketacceptance or rejection. In no ca
37、se shall the loading range bestated as including loads below the value which is 100 timesthe smallest change of load estimable on the load-indicatingmechanism of the testing machine or loads within that portionof the range below 10 % of the maximum range capacity.6.1.3.5 In no case shall the loading
38、 range be stated asincluding loads outside the range of loads applied during theverification test.6.1.3.6 The indicated load of a testing machine shall not becorrected either by calculation or by the use of a calibrationdiagram to obtain values within the required permissiblevariation.6.2 Bearing Bl
39、ocksThe upper and lower bearing blocksshall conform to the following requirements:6.2.1 Bearing blocks shall be steel with hardened bearingfaces (Note 3).6.2.2 Bearing faces shall have dimensions at least 3 %greater than the nominal diameter of the specimen.6.2.3 Except for the inscribed concentric
40、circles describedin 6.2.4.7, the bearing faces shall not depart from a plane bymore than 0.02 mm 0.001 in. along any 150 mm 6 in. lengthfor bearing blocks with a diameter of 150 mm 6 in. or larger,or by more than 0.02 mm 0.001 in. in any direction of smallerbearing blocks. New bearing blocks shall b
41、e manufacturedwithin one half of this tolerance.NOTE 3It is desirable that the bearing faces of bearing blocks have aRockwell hardness at least 55 HRC as determined by Test Methods E18.NOTE 4Square bearing faces are permissible for the bearing blocks.6.2.4 Upper Bearing BlockThe upper bearing block
42、shallconform to the following requirements:6.2.4.1 The upper bearing block shall be spherically seatedand the center of the sphere shall coincide with the center of thebearing face within 65 % of the radius of the sphere.6.2.4.2 The ball and the socket shall be designed so that thesteel in the conta
43、ct area does not permanently deform whenloaded to the capacity of the testing machine.NOTE 5The preferred contact area is in the form of a ring (describedas preferred bearing area) as shown in Fig. 1.6.2.4.3 Provision shall be made for holding the upperbearing block in the socket. The design shall b
44、e such that thebearing face can be rotated and tilted at least 4 in anydirection.6.2.4.4 If the upper bearing block is a two-piece designcomposed 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 p
45、late.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 portionof the bearing face extending beyond the sphere shall have athickness not less than the difference between the
46、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 Diameterof Specimen,mm in.Max
47、imum Diameterof Round BearingFace, mm in.Maximum Dimensionsof Square BearingFace, mm in.50 2 105 4 105 by 105 4 by 475 3 130 5 130 by 130 5 by 5100 4 165 6.5 165 by 165 6.5 by 6.5150 6 255 10 255 by 255 10 by 10200 8 280 11 280 by 280 11 by 116.2.4.7 If the diameter of the bearing face of the upperb
48、earing block exceeds the nominal diameter of the specimen bymore than 13 mm 0.5 in., concentric circles not more than 0.8mm 0.03 in. deep and not more than 1 mm 0.04 in. wideshall be inscribed on the face of upper bearing block tofacilitate proper centering.T R rr = radius of spherical portion of up
49、per bearing blockR = nominal radius of specimenT = thickness of upper bearing block extending beyond thesphereFIG. 1 Schematic Sketch of Typical Upper Bearing BlockC39/C39M 1836.2.4.8 At least every six months, or as specified by themanufacturer of the testing machine, clean and lubricate thecurved surfaces of the socket and of the spherical portion of theupper bearing block. The lubricant shall be a petroleum-typeoil such as conventional motor oil or as specified by themanufacturer of the testing m
