1、Designation: C 496/C 496M 04e1Standard Test Method forSplitting Tensile Strength of Cylindrical ConcreteSpecimens1This standard is issued under the fixed designation C 496/C 496M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the
2、 year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.e1NOTEFootnote 3 was reinserted editori
3、ally to correct a typo in December 2006.1. 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 inch-pound or SI units are tobe regarded separately as standa
4、rd. 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 two systems mayresult in nonconformance with the standard.1.3 This standard does not purport to address all o
5、f 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 provideexplana
6、tory 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 Curing Concrete TestSpecimens in the FieldC 39/C 39M Test Method for Compressive Strength of Cy-lindrical Concrete SpecimensC 42/C 42M Test
7、Method for Obtaining and Testing DrilledCores and Sawed Beams of ConcreteC 192/C 192M Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC 670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Materials3. Summary of Test Method3.1 This test met
8、hod 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
9、immediately around the applied load.Tensile failure occurs rather than compressive failure becausethe areas of load application are in a state of triaxial compres-sion, thereby allowing them to withstand much higher com-pressive stresses than would be indicated by a uniaxial com-pressive strength te
10、st 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
11、 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 reinf
12、orcement.5. Apparatus5.1 Testing MachineThe testing machine shall conform tothe requirements of Test Method C 39/C 39M 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
13、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 0.001 in. 0.025 mm of planeness, as measured onany line of contact of t
14、he bearing area. It shall have a width ofat least 2 in. 50 mm, and a thickness not less than the distance1This 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
15、 approved Feb. 1, 2004. Published March 2004. Originallyapproved in 1962. Last previous edition approved in 1996 as C 496 96.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information,
16、refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.from the edge of the spherical or rectangular bearing b
17、lock tothe 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 nominal18 in.3.2 mm thick plywood, free of imperfections, approximately1 in. 25 mm wide, and of a length equal to,
18、or slightly longerthan, that of the specimen shall be provided for each specimen.The bearing strips shall be placed between the specimen andboth the upper and lower bearing blocks of the testing machineor between the specimen and supplemental bars or plates, whenused (see 5.2). Bearing strips shall
19、not be reused.6. Test Specimens6.1 The test specimens shall conform to the size, molding,and curing requirements set forth in either Practice C 31/C 31M (field specimens) or Practice C 192/C 192M (labora-tory specimens). Drilled cores shall conform to the size andmoisture-conditioning requirements s
20、et forth in Test MethodC 42/C 42M. Moist-cured specimens, during the period be-tween their removal from the curing environment and testing,shall be kept moist by a wet burlap or blanket covering, andshall be tested in a moist condition as soon as practicable.6.2 The following curing procedure shall
21、be used for evalu-ations of light-weight concrete: specimens tested at 28 daysshall be in an air-dry condition after 7 days moist curingfollowed by 21 days drying at 73.5 6 3.5F 23.0 6 2.0C and50 6 5 % relative humidity.7. Procedure7.1 MarkingDraw diametral lines on each end of thespecimen using a s
22、uitable device that will ensure that they arein the same axial plane (see Fig. 1, Fig. 2 and Note 1), or as analternative, use the aligning jig shown in Fig. 3 (Note 2).NOTE 1Figs. 1 and 2 show a suitable device for drawing diametrallines on each end of a 6 in. by 12 in. 150 mm by 300 mm cylinder in
23、 thesame axial plane. The device consists of three parts as follows:(1) A length of 4-in. 100-mm steel channel, the flanges of which havebeen machined flat,(2) A section, part a, that is grooved to fit smoothly over the flanges ofthe channel and that includes cap screws for positioning the verticalm
24、ember of the assembly, and(3) A vertical bar, part b, for guiding a pencil or marker,The assembly (part a and part b) is not fastened to the channel and ispositioned at either end of the cylinder without disturbing the position ofthe specimen when marking the diametral lines.NOTE 2Fig. 4 is a detail
25、ed drawing of the aligning jig shown in Fig.3 for achieving the same purpose as marking the diametral lines. Thedevice consists of:(1) A base for holding the lower bearing strip and cylinder,(2) A supplementary bearing bar conforming to the requirements inSection 5 as to critical dimensions and plan
26、eness, and(3) Two uprights to serve for positioning the test cylinder, bearingstrips, and supplementary bearing bar.7.2 MeasurementsDetermine the diameter of the testspecimen to the nearest 0.01 in. 0.25 mm by averaging threediameters measured near the ends and the middle of thespecimen and lying in
27、 the plane containing the lines marked onthe two ends. Determine the length of the specimen to thenearest 0.1 in. 2 mm by averaging at least two lengthmeasurements taken in the plane containing the lines markedon the two ends.7.3 Positioning Using Marked Diametral LinesCenterone of the plywood strip
28、s along the center of the lower bearingblock. Place the specimen on the plywood strip and align sothat the lines marked on the ends of the specimen are verticaland centered over the plywood strip. Place a second plywoodstrip lengthwise on the cylinder, centered on the lines markedon the ends of the
29、cylinder. Position the assembly to ensure thefollowing conditions:FIG. 1 General Views of a Suitable Apparatus for Marking End Diameters Used for Alignment of Specimen in Testing MachineC 496/C 496M 04e127.3.1 The projection of the plane of the two lines marked onthe ends of the specimen intersects
30、the center of the upperbearing plate, and7.3.2 The supplementary bearing bar or plate, when used,and the center of the specimen are directly beneath the centerof thrust of the spherical bearing block (see Fig. 5).7.4 Positioning by Use of Aligning JigPosition the bear-ing strips, test cylinder, and
31、supplementary bearing bar bymeans of the aligning jig as illustrated in Fig. 3 and center thejig so that the supplementary bearing bar and the center of thespecimen are directly beneath the center of thrust of thespherical bearing block.7.5 Rate of LoadingApply the load continuously andwithout shock
32、, at a constant rate within the range 100 to 200psi/min 0.7 to 1.4 MPa/min splitting tensile stress until failureof the specimen (Note 3). Record the maximum applied loadindicated by the testing machine at failure. Note the type offailure and the appearance of the concrete.NOTE 3The relationship bet
33、ween splitting tensile stress and appliedload is shown in Section 8. The required loading range in splitting tensilestress corresponds to applied total load in the range of 11 300 to 22 600lbf 50 to 100 kN/min for 6 by 12-in. 150 by 300-mm cylinders.FIG. 2 Detailed Plans for a Suitable Apparatus for
34、 Marking End Diameters Used for Aligning the SpecimenFIG. 3 Jig for Aligning Concrete Cylinder and Bearing StripsC 496/C 496M 04e138. Calculation8.1 Calculate the splitting tensile strength of the specimenas follows:T 5 2P/pld (1)where:T = splitting tensile strength, psi MPa,P = maximum applied load
35、 indicated by the testing ma-chine, lbf N,l = length, in. mm, andd = diameter, in. mm.FIG. 4 Detailed Plans for a Suitable Aligning Jig for 6 by 12 in. 150 by 300 mm SpecimenFIG. 5 Specimen Positioned in a Testing Machine for Determination of Splitting Tensile StrengthC 496/C 496M 04e149. Report9.1
36、Report the following information:9.1.1 Identification number,9.1.2 Diameter and length, in. mm,9.1.3 Maximum load, lbf N,9.1.4 Splitting tensile strength calculated to the nearest 5 psi0.05 MPa,9.1.5 Estimated proportion of coarse aggregate fracturedduring test,9.1.6 Age of specimen,9.1.7 Curing his
37、tory,9.1.8 Defects in specimen,9.1.9 Type of fracture, and9.1.10 Type of specimen.10. Precision and Bias10.1 PrecisionAn interlaboratory study of this testmethod has not been performed. Available research data,3however, suggests that the within batch coefficient of variationis 5 % (see Note 4) for 6
38、 3 12-in. 150 3 300-mm cylindricalspecimens with an average splitting tensile strength of 405 psi2.8 MPa. Results of two properly conducted tests on the samematerial, therefore, should not differ by more than 14 % (seeNote 4) of their average for splitting tensile strengths of about400 psi 2.8 MPa.N
39、OTE 4These numbers represent, respectively, the (1s %) and(d2s %) limits as defined in Practice C 670.10.2 BiasThe test method has no bias because the split-ting tensile strength can be defined only in terms of this testmethod.11. Keywords11.1 cylindrical concrete specimens; splitting tension; ten-s
40、ile strengthSUMMARY OF CHANGESCommittee C09 has identified the location of selected changes to this test method since the last issue,C 496 96, that may impact the use of this test method. (Approved February 1, 2004)(1) Revised 1.2.(2) Added 1.4.(3) Revised 5.1, 6.1, Section 2, and Note 1 to correct
41、refer-ences.(4) Revised 5.2, 6.2, 7.2, 7.5, 10.1, and Note 4 by metricationrules.(5) Revised Section 4.(6) Revised 3.2 and 5.3.(7) Revised Note 2.(8) Figs. 1, 2, and 4 were revised and redrawn.ASTM International takes no position respecting the validity of any patent rights asserted in connection wi
42、th any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible tech
43、nical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful considerat
44、ion at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Ha
45、rbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).3Wright, P. J. F., “Comments on an Indirect Tensile Test on Concrete Cylinders,”Magazine of Concrete Research, Vol 7, No. 20, July 1955, pp. 8795.C 496/C 496M 04e15
