1、Designation: C 39/C 39M 052Standard Test Method forCompressive Strength of Cylindrical Concrete Specimens1This standard is issued under the fixed designation C 39/C 39M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of l
2、ast 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 Department of Defense.1NOTENote 1 was corrected editorially in September
3、 2006.2NOTERemoved research report footnote from Section 10 editorially in October 2008.1. Scope1.1 This test method covers determination of compressivestrength of cylindrical concrete specimens such as moldedcylinders and drilled cores. It is limited to concrete having aunit weight in excess of 50
4、lb/ft3800 kg/m3.1.2 The values stated in either inch-pound or SI units are tobe regarded separately as standard. The SI units are shown inbrackets. The values stated in each system may not be exactequivalents; therefore, each system shall be used independentlyof the other. Combining values from the
5、two systems mayresult in nonconformance with 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-bil
6、ity of regulatory limitations prior to use. (WarningMeansshould be provided to contain concrete fragments duringsudden rupture of specimens. Tendency for sudden ruptureincreases with increasing concrete strength and it is more likelywhen the testing machine is relatively flexible. The safetyprecauti
7、ons given in the Manual of Aggregate and ConcreteTesting are recommended.)1.4 The text of this standard references notes which provideexplanatory material. These notes shall not be considered asrequirements of the standard.2. Referenced Documents2.1 ASTM Standards:2C 31/C 31M Practice for Making and
8、 Curing Concrete TestSpecimens in the FieldC 42/C 42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of ConcreteC 192/C 192M Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC 617 Practice for Capping Cylindrical Concrete Speci-mensC 670 Practice for Prepari
9、ng Precision and Bias Statementsfor Test Methods for Construction MaterialsC 873 Test Method for Compressive Strength of ConcreteCylinders Cast in Place in Cylindrical MoldsC 1077 Practice for Laboratories Testing Concrete and Con-crete Aggregates for Use in Construction and Criteria forLaboratory E
10、valuationC 1231/C 1231M Practice for Use of Unbonded Caps inDetermination of Compressive Strength of Hardened Con-crete CylindersE4 Practices for Force Verification of Testing MachinesE74 Practice of Calibration of Force-Measuring Instru-ments for Verifying the Force Indication of Testing Ma-chinesM
11、anual of Aggregate and Concrete Testing3. Summary of Test Method3.1 This test method consists of applying a compressiveaxial 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-
12、mum load attained during the test by the cross-sectional area ofthe specimen.4. Significance and Use4.1 Care must be exercised in the interpretation of thesignificance of compressive strength determinations by this testmethod since strength is not a fundamental or intrinsic propertyof concrete made
13、from given materials. Values obtained willdepend on the size and shape of the specimen, batching, mixing1This 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
14、approved Nov. 1, 2005. Published November 2005. Originallyapproved in 1921. Last previous edition approved in 2004 as C 39/C 39M 04a.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume infor
15、mation, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.procedures, the methods of sampling, molding, and fabricationand the age, temperature, and moisture conditions du
16、ringcuring.4.2 This test method is used to determine compressivestrength of cylindrical specimens prepared and cured in accor-dance with Practices C 31/C 31M, C 192/C 192M, C 617, andC 1231/C 1231M and Test Methods C 42/C 42M and C 873.4.3 The results of this test method are used as a basis forquali
17、ty control of concrete proportioning, mixing, 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 technici
18、anrequirements of Practice C 1077, including 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 t
19、his requirement.5. Apparatus5.1 Testing MachineThe testing machine shall be of atype having sufficient capacity and capable of providing therates of loading prescribed in 7.5.5.1.1 Verify calibration of the testing machines in accor-dance with Practices E4, except that the verified loading rangeshal
20、l be as required in 5.3. Verification is required under thefollowing conditions:5.1.1.1 At least annually, but not to exceed 13 months,5.1.1.2 On original installation or immediately after reloca-tion,5.1.1.3 Immediately after making repairs or adjustmentsthat affect the operation of the force apply
21、ing system or thevalues displayed on the load indicating system, except for zeroadjustments 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 thefollo
22、wing features:5.1.2.1 The machine must be power operated and mustapply the load continuously rather than intermittently, andwithout shock. If it has only one loading rate (meeting therequirements of 7.5), it must be provided with a supplementalmeans for loading at a rate suitable for verification. T
23、hissupplemental means of loading may be power or hand oper-ated.5.1.2.2 The space 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 which
24、complies with the requirements of Practice E74.NOTE 2The types of elastic calibration devices most generally avail-able and most commonly used for this purpose are the circular provingring or load cell.5.1.3 AccuracyThe accuracy of the testing machine shallbe in accordance with the following provisi
25、ons:5.1.3.1 The percentage of error for the loads within theproposed range of use of the testing machine shall not exceed61.0 % of the indicated load.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
26、 difference between any twosuccessive test loads shall not exceed one third of the differ-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
27、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, lbf kN indicated by the machine being verified,andB = applied load, lbf kN as determined by the calibratingdevice.5.1.3.4 The report on the verification
28、 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 case shall the loading range bestated as including loads below the value which is 100 timesthe smallest change of load estimab
29、le on the load-indicatingmechanism of the testing machine or loads within that portionof 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
30、 of a testing machine shall not becorrected either by calculation or by the use of a 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 b
31、lock that will bear on the upper surface ofthe specimen, and the other a solid block 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 be
32、aring faces shall not depart from a planeby more than 0.001 in. 0.02 mm in any 6 in. 150 mm ofblocks 6 in. 150 mm in diameter or larger, or by more than0.001 in. 0.02 mm in the diameter of any smaller block; andnew blocks shall be manufactured within one half of thistolerance. When the diameter of t
33、he bearing face of thespherically seated block exceeds the diameter of the specimenby more than 0.5 in. 13 mm, concentric circles not more than0.03 in. 0.8 mm deep and not more than 0.04 in. 1 mm wideshall be inscribed to facilitate proper centering.NOTE 3It is desirable that the bearing faces of bl
34、ocks used forcompression testing of concrete have a Rockwell hardness of not less than55 HRC.5.2.1 Bottom bearing blocks shall conform to the followingrequirements:C 39/C 39M 05225.2.1.1 The bottom bearing block is specified for the pur-pose of providing a readily machinable surface for mainte-nance
35、 of the specified surface conditions (Note 4). The top andbottom surfaces shall be parallel to each 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
36、least 3 %greater than the diameter of the specimen to be tested.Concentric circles as 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 b
37、earing block is used toassist in centering the specimen, the center of the concentricrings, 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 bearin
38、g block shall be at least 1 in. 25mm thick when new, and at least 0.9 in. 22.5 mm thick 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 shal
39、l not exceed the valuesgiven below:Diameter of Maximum DiameterTest Specimens, of Bearing Face,in. mm in. mm2 50 4 1053 75 5 1304 100 6.5 1656 150 10 2558 200 11 280NOTE 5Square bearing faces are permissible, provided the diameterof the largest possible inscribed circle does not exceed the above dia
40、meter.5.2.2.2 The center of the sphere shall coincide with thesurface of the bearing face 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 the
41、steel in the contact area does not permanently deform whenloaded to the capacity of the 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 The curved surfaces of the socket and of the spheri-cal portion shall be
42、 kept clean and shall be lubricated with apetroleum-type oil such as conventional motor oil, not with apressure type grease. After contacting the specimen and appli-cation of small initial load, further tilting of the sphericallyseated block is not intended and is undesirable.5.2.2.5 If the radius o
43、f the sphere is smaller than the radiusof the largest specimen to be tested, the portion of the bearingface extending 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 le
44、ast as great as the diameter of the sphere (see Fig.1).5.2.2.6 The movable portion of the bearing block shall 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 b
45、earing block is atwo-piece design composed of a spherical portion and abearing plate, a mechanical means shall 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 registere
46、d on a dial, the dial shall be provided with agraduated scale that is readable to at least the nearest 0.1 % ofthe full scale load (Note 7). 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 becons
47、idered to include loads below the value that is 100 timesthe smallest change of load that can be read on the scale. 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
48、 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
49、device thatat all times, until reset, will indicate to within 1 % accuracy themaximum load applied to the specimen.NOTE 7Readability is considered to be 0.02 in. 0.5 mm along the arcdescribed by the end of the pointer. Also, one half of a scale interval isreadable with reasonable certainty when the spacing on the load indicatingmechanism is between 0.04 in. 1 mm and 0.06 in. 2 mm. When thespacing is between 0.06 and 0.12 in. 2 and 3 mm, one third of a scaleinterval is readable with reasonable certainty. When
