1、Designation: C39/C39M 15aStandard 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
2、revision. 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 determinatio
3、n 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 unitsa
4、re 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 conc
5、erns, 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. (WarningMeansshould be provided to contain concrete fragments duringsudden ruptur
6、e of specimens. Tendency for sudden ruptureincreases with increasing concrete strength and it is more likelywhen the testing machine is relatively flexible. The safetyprecautions given in the Manual of Aggregate and ConcreteTesting are recommended.)1.4 The text of this standard references notes whic
7、h 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 FieldC42/C42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of Concr
8、eteC192/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 Construction MaterialsC873/C873M Test Method for Compressive Strength ofConc
9、rete Cylinders Cast in Place in Cylindrical MoldsC1077 Practice for Agencies Testing Concrete and ConcreteAggregates for Use in Construction and Criteria forTesting Agency EvaluationC1231/C1231M Practice for Use of Unbonded Caps inDetermination of Compressive Strength of Hardened Con-crete Cylinders
10、E4 Practices for Force Verification of Testing MachinesE74 Practice of Calibration of Force-Measuring Instrumentsfor Verifying the Force Indication of Testing MachinesManual of Aggregate and Concrete Testing3. Summary of Test Method3.1 This test method consists of applying a compressiveaxial load to
11、 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.4. Significance and Use4.1 Care must be exercised in th
12、e 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, the methods of s
13、ampling, molding, and fabricationand the age, temperature, and moisture conditions duringcuring.4.2 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,and C1231/C1231M and Test Methods C
14、42/C42M and C873/C873M.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 April 1, 2015. Published May 2015. Originallyapproved in 1921. Last prev
15、ious edition approved in 2015 as C39/C39M 15. DOI:10.1520/C0039_C0039M-15A.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
16、 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 States14.3 The results of this test method are used as a basis forquality control of concrete proportioning, mixin
17、g, and placingoperations; determination of compliance with specifications;control for evaluating effectiveness of admixtures; and similaruses.4.4 The individual who tests concrete cylinders for accep-tance testing shall meet the concrete laboratory technicianrequirements of Practice C1077, including
18、 an examinationrequiring performance demonstration that is evaluated by anindependent examiner.NOTE 1Certification equivalent to the minimum guidelines for ACIConcrete Laboratory Technician, Level I or ACI Concrete StrengthTesting Technician will satisfy this requirement.5. Apparatus5.1 Testing Mach
19、ineThe testing machine shall be of a typehaving sufficient capacity and capable of providing the rates ofloading prescribed in 7.5.5.1.1 Verify the accuracy of the testing machine in accor-dance with Practices E4, except that the verified loading rangeshall be as required in 5.3. Verification is req
20、uired:5.1.1.1 Within 13 months of the last calibration,5.1.1.2 On original installation or immediately afterrelocation,5.1.1.3 Immediately after making repairs or adjustmentsthat affect the operation of the force applying system or thevalues displayed on the load indicating system, except for zeroad
21、justments that compensate for the mass of bearing blocks orspecimen, or both, or5.1.1.4 Whenever there is reason to suspect the accuracy ofthe indicated loads.5.1.2 DesignThe design of the machine must include thefollowing features:5.1.2.1 The machine must be power operated and mustapply the load co
22、ntinuously rather than intermittently, andwithout shock. If it has only one loading rate (meeting therequirements of 7.5), 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.5.1.2.2 The space
23、provided for test specimens shall be largeenough to accommodate, in a readable position, an elasticcalibration 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 calibrat
24、ion devices most generallyavailable and most commonly used for this purpose are the circularproving ring or load cell.5.1.3 AccuracyThe accuracy of the testing machine shallbe in accordance with the following provisions:5.1.3.1 The percentage of error for the loads within theproposed range of use of
25、 the testing machine shall not exceed61.0 % of the indicated load.5.1.3.2 The accuracy of the 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 d
26、iffer-ence between the maximum and minimum test loads.5.1.3.3 The test load as indicated by 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 t
27、hesedata as follows:E 5 A 2 B (1)Ep5 100A 2 B!/Bwhere:A = load, kN lbf indicated by the machine being verified,andB = applied load, kN lbf as determined by the calibratingdevice.5.1.3.4 The report on the verification of a testing machineshall state within what loading range it was found to conformto
28、 specification requirements rather than reporting a blanketacceptance or rejection. In no case 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 porti
29、onof the range below 10 % of the maximum range capacity.5.1.3.5 In no case shall the loading range be stated asincluding loads outside the range of loads applied during theverification test.5.1.3.6 The indicated load of a testing machine shall not becorrected either by calculation or by the use of a
30、 calibrationdiagram to obtain values within the required permissiblevariation.5.2 The testing machine shall be equipped with two steelbearing blocks with hardened faces (Note 3), one of which is aspherically seated block that will bear on the upper surface ofthe specimen, and the other a solid block
31、 on which thespecimen shall rest. Bearing faces of the blocks shall have aminimum dimension at least 3 % greater than the diameter ofthe specimen to be tested. Except for the concentric circlesdescribed below, the bearing faces shall not depart from a planeby more than 0.02 mm 0.001 in. in any 150 m
32、m 6 in. ofblocks 150 mm 6 in. in diameter or larger, or by more than0.02 mm 0.001 in. in the diameter of any smaller block; andnew blocks shall be manufactured within one half of thistolerance. When the diameter of the bearing face of thespherically seated block exceeds the diameter of the specimenb
33、y more than 13 mm 0.5 in., concentric circles not more than0.8 mm 0.03 in. deep and not more than 1 mm 0.04 in. wideshall be inscribed to facilitate proper centering.NOTE 3It is desirable that the bearing faces of blocks used forcompression testing of concrete have a Rockwell hardness of not less th
34、an55 HRC.5.2.1 Bottom bearing blocks shall conform to the followingrequirements:5.2.1.1 The bottom bearing block is specified for the pur-pose of providing a readily machinable surface for mainte-nance of the specified surface conditions (Note 4). The top andbottom surfaces shall be parallel to each
35、 other. If the testingmachine is so designed that the platen itself is readily main-tained in the specified surface condition, a bottom block is notrequired. Its least horizontal dimension shall be at least 3 %C39/C39M 15a2greater than the diameter of the specimen to be tested.Concentric circles as
36、described in 5.2 are optional on thebottom block.NOTE 4The block may be fastened to the platen of the testingmachine.5.2.1.2 Final centering must be made with reference to theupper spherical block. When the lower bearing block is used toassist in centering the specimen, the center of the concentricr
37、ings, when provided, or the center of the block itself must bedirectly below the center of the spherical head. Provision shallbe made on the platen of the machine to assure such a position.5.2.1.3 The bottom bearing block shall be at least 25 mm 1in. thick when new, and at least 22.5 mm 0.9 in. thic
38、k afterany resurfacing operations.5.2.2 The spherically seated bearing block shall conform tothe following requirements:5.2.2.1 The maximum diameter of the bearing face of thesuspended spherically seated block shall not exceed the valuesgiven below:Diameter of Maximum DiameterTest Specimens, of Bear
39、ing Face,mm in. mm in.50 2 105 475 3 130 5100 4 165 6.5150 6 255 10200 8 280 11NOTE 5Square bearing faces are permissible, provided the diameter ofthe largest possible inscribed circle does not exceed the above diameter.5.2.2.2 The center of the sphere shall coincide with thesurface of the bearing f
40、ace within a tolerance of 65 % of theradius of the sphere. The diameter of the sphere shall be at least75 % of the diameter of the specimen to be tested.5.2.2.3 The ball and the socket shall be designed so that thesteel in the contact area does not permanently deform whenloaded to the capacity of th
41、e testing machine.NOTE 6The preferred contact area is in the form of a ring (describedas “preferred bearing area”) as shown on Fig. 1.5.2.2.4 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 spherica
42、l portion of themachine. The lubricant shall be a petroleum-type oil such asconventional motor oil or as specified by the manufacturer ofthe testing machine.NOTE 7To ensure uniform seating, the spherically seated head isdesigned to tilt freely as it comes into contact with the top of the specimen.Af
43、ter contact, further rotation is undesirable. Friction between the socketand the spherical portion of the head provides restraint against furtherrotation during loading. Petroleum-type oil such as conventional motor oilhas been shown to permit the necessary friction to develop. Pressure-typegreases
44、can reduce the desired friction and permit undesired rotation of thespherical head and should not be used unless recommended by themanufacturer of the testing machine.5.2.2.5 If the radius of the sphere is smaller than the radiusof the largest specimen to be tested, the portion of the bearingface ex
45、tending beyond the sphere shall have a thickness notless than the difference between the radius of the sphere andradius of the specimen. The least dimension of the bearing faceshall be at least as great as the diameter of the sphere (see Fig.1).5.2.2.6 The movable portion of the bearing block shall
46、beheld closely in the spherical seat, but the design shall be suchthat the bearing face can be rotated freely and tilted at least 4in any direction.5.2.2.7 If the ball portion of the upper bearing block is atwo-piece design composed of a spherical portion and abearing plate, a mechanical means shall
47、 be provided to ensurethat the spherical portion is fixed and centered on the bearingplate.5.3 Load Indication:5.3.1 If the load of a compression machine used in concretetesting is registered on a dial, the dial shall be provided with agraduated scale that is readable to at least the nearest 0.1 % o
48、fthe full scale load (Note 8). The dial shall be readable within1 % of the indicated load at any given load level within theloading range. In no case shall the loading range of a dial beconsidered to include loads below the value that is 100 timesthe smallest change of load that can be read on the s
49、cale. Thescale shall be provided with a graduation line equal to zero andso numbered. The dial pointer shall be of sufficient length toreach the graduation marks; the width of the end of the pointershall not exceed the clear distance between the smallestgraduations. Each dial shall be equipped with a zero adjust-ment located outside the dialcase and easily accessible from thefront of the machine while observing the zero mark and dialpointer. Each dial shall be equipped with a suitable device thatat all times, until reset,
