ASTM C469 C469M-2010 Standard Test Method for Static Modulus of Elasticity and Poissons Ratio of Concrete in Compression《压缩混凝土的静态弹性模量和泊松比的标准测试方法》.pdf

《ASTM C469 C469M-2010 Standard Test Method for Static Modulus of Elasticity and Poissons Ratio of Concrete in Compression《压缩混凝土的静态弹性模量和泊松比的标准测试方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM C469 C469M-2010 Standard Test Method for Static Modulus of Elasticity and Poissons Ratio of Concrete in Compression《压缩混凝土的静态弹性模量和泊松比的标准测试方法》.pdf（5页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: C469/C469M 10Standard Test Method forStatic Modulus of Elasticity and Poissons Ratio of Concretein Compression1This standard is issued under the fixed designation C469/C469M; the number immediately following the designation indicates the yearof original adoption or, in the case of revis

2、ion, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers determination of (1) chordmodulus of elasticity (Youngs) and (2) Poissons rat

3、io ofmolded concrete cylinders and diamond-drilled concrete coreswhen under longitudinal compressive stress. Chord modulus ofelasticity and Poissons ratio are defined in Terminology E6.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values s

4、tated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its u

5、se. 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.2. Referenced Documents2.1 ASTM Standards:2C31/C31M Practice for Making and Curing Concrete TestSpecimens in the Fiel

6、dC39/C39M Test Method for Compressive Strength of Cy-lindrical Concrete SpecimensC42/C42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of ConcreteC174/C174M Test Method for Measuring Thickness ofConcrete Elements Using Drilled Concrete CoresC192/C192M Practice for Making and Cu

7、ring ConcreteTest Specimens in the LaboratoryC617 Practice for Capping Cylindrical Concrete SpecimensE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and Classification of Exten-someter SystemsE177 Practice f

8、or Use of the Terms Precision and Bias inASTM Test Methods2.2 ASTM Adjuncts:Compressometers (two drawings) and Extensometers (twodrawings)33. Significance and Use3.1 This test method provides a stress to strain ratio valueand a ratio of lateral to longitudinal strain for hardenedconcrete at whatever

9、 age and curing conditions may bedesignated.3.2 The modulus of elasticity and Poissons ratio values,applicable within the customary working stress range (0 to40 % of ultimate concrete strength), are used in sizing ofreinforced and nonreinforced structural members, establishingthe quantity of reinfor

10、cement, and computing stress for ob-served strains.3.3 The modulus of elasticity values obtained will usuallybe less than moduli derived under rapid load application(dynamic or seismic rates, for example), and will usually begreater than values under slow load application or extendedload duration, g

11、iven other test conditions being the same.4. Apparatus4.1 Testing MachineUse a testing machine capable ofimposing a load at the rate and of the magnitude prescribed in6.4. The machine shall conform to the requirements of Prac-tices E4 (Constant-Rate of-Traverse CRT-Type Testing Ma-chines section). T

12、he spherical head and bearing blocks shallconform to the Apparatus Section of Test Method C39/C39M.4.2 Compressometer3For determining the modulus ofelasticity use a bonded (Note 1) or unbonded sensing devicethat measures to the nearest 5 millionths the average deforma-tion of two diametrically oppos

13、ite gauge lines, each parallel tothe axis, and each centered about midheight of the specimen.The effective length of each gauge line shall be not less thanthree times the maximum size of the aggregate in the concretenor more than two thirds the height of the specimen; the1This test method is under t

14、he jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.61 on Testing for Strength.Current edition approved Oct. 1, 2010. Published November 2010. Originallyapproved in 1961. Last previous edition approved in 2002 as C469 021. DOI:

15、10.1520/C0469_C0469M-10.2For 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.3Available from ASTM International He

16、adquarters. Order Adjunct No.ADJC0469.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.preferred length of the gauge line is one half the height of thespecimen. Either use gauge points embedded in or cemented tothe specimen, and read

17、deformation of the two lines indepen-dently; or use a compressometer (such as is shown in Fig. 1)consisting of two yokes, one of which (see B, Fig. 1) is rigidlyattached to the specimen and the other (see C, Fig. 1) attachedat two diametrically opposite points so that it is free to rotate.At one poi

18、nt on the circumference of the rotating yoke,midway between the two support points, use a pivot rod (see A,Fig. 1) to maintain a constant distance between the two yokes.At the opposite point on the circumference of the rotating yoke,the change in distance between the yokes (that is, the gaugereading

19、) is equal to the sum of the displacement due tospecimen deformation and the displacement due to rotation ofthe yoke about the pivot rod (see Fig. 2).4.2.1 Measure deformation by a dial gauge used directly orwith a lever multiplying system, by a wire strain gauge, or bya linear variable differential

20、 transformer. If the distances of thepivot rod and the gauge from the vertical plane passing throughthe support points of the rotating yoke are equal, the deforma-tion of the specimen is equal to one-half the gauge reading. Ifthese distances are not equal, calculate the deformation asfollows:d 5 ger

21、/er1 eg! (1)where:d = total deformation of the specimen throughout theeffective gauge length, m in.,g = gauge reading, m in.,er= the perpendicular distance, measured to the nearest 0.2mm 0.01 in. from the pivot rod to the vertical planepassing through the two support points of the rotatingyoke, ande

22、g= the perpendicular distance, measured to the nearest 0.2mm 0.01 in. from the gauge to the vertical planepassing through the two support points of the rotatingyoke.Procedures for calibrating strain-measuring devices aregiven in Practice E83.NOTE 1Although bonded strain gauges are satisfactory on dr

23、y speci-mens, they may be difficult, if not impossible, to mount on specimenscontinually moist-cured until tested.4.3 Extensometer3If Poissons ratio is desired, the trans-verse strain shall be determined (1) by an unbonded extensom-eter capable of measuring to the nearest 0.5 m 25 in. thechange in d

24、iameter at the midheight of the specimen, or (2)bytwo bonded strain gauges (Note 1) mounted circumferentiallyat diametrically opposite points at the midheight of thespecimen and capable of measuring circumferential strain tothe nearest 5 millionths. A combined compressometer andextensometer (Fig. 3)

25、 is a convenient unbonded device. Thisapparatus shall contain a third yoke (consisting of two equalsegments) located halfway between the two compressometeryokes and attached to the specimen at two diametricallyopposite points. Midway between these points use a short pivotrod ( A8, see Fig. 3), adjac

26、ent to the long pivot rod, to maintaina constant distance between the bottom and middle yokes.Hinge the middle yoke at the pivot point to permit rotation ofthe two segments of the yoke in the horizontal plane. At theopposite point on the circumference, connect the two segmentsthrough a dial gauge or

27、 other sensing device capable ofmeasuring transverse deformation to the nearest 1.27 m 50in. If the distances of the hinge and the gauge from thevertical plane passing through the support points of the middleyoke are equal, the transverse deformation of the specimenFIG. 1 Suitable Compressometerd =

28、displacement due to specimen deformationr = displacement due to rotation of the yoke about the pivot roda = location of gaugeb = support point of the rotating yokec = location of pivot rodg = gauge readingFIG. 2 Diagram of DisplacementsC469/C469M 102diameter is equal to one-half the gauge reading. I

29、f thesedistances are not equal, calculate the transverse deformation ofthe specimen diameter in accordance with Eq 2.d8 5 g8e8h/e8h1 e8g! (2)where:d8 = transverse deformation of the specimen diameter, min.,g8 = transverse gauge reading, m in.,e8h= the perpendicular distance, measured to the nearest0

30、.2 mm 0.01 in. from the hinge to the vertical planepassing through the support points of the middleyoke, ande8g= the perpendicular distance, measured to the nearest0.2 mm 0.01 in. from the gauge to the vertical planepassing through the support points of the middleyoke.4.4 Balance or Scale, accurate

31、to 50 g 0.1 lb shall be usedif necessary.5. Test Specimens5.1 Molded Cylindrical SpecimensMold test cylinders inaccordance with the requirements for compression test speci-mens in Practice C192/C192M, or in Practice C31/C31M.Subject specimens to the specified curing conditions and test atthe age for

32、 which the elasticity information is desired. Testspecimens within 1 h after removal from the curing or storageroom. Specimens removed from a moist room for test shall bekept moist by a wet cloth covering during the interval betweenremoval and test.5.2 Drilled Core SpecimensCores shall comply with t

33、herequirements for drilling, and moisture conditioning applicableto compressive strength specimens in Test Method C42/C42M,except that only diamond-drilled cores having a length-to-diameter ratio greater than 1.50 shall be used. Requirementsrelative to storage and to ambient conditions immediately p

34、riorto test shall be the same as for molded cylindrical specimens.5.3 The ends of the test specimens shall be made perpen-dicular to the axis 60.001 rad 60.5 and plane within 0.05mm 0.002 in. If the specimen as cast does not meet theplaneness requirements, planeness shall be accomplished bycapping i

35、n accordance with Practice C617, or by lapping, or bygrinding. It is not prohibited to repair aggregate popouts thatoccur at the ends of specimens, provided the total area ofpopouts does not exceed 10 % of the specimen area and therepairs are made before capping or grinding is completed (Note2). Pla

36、neness will be considered within tolerance when a 0.05mm 0.002 in. feeler gauge will not pass between thespecimen surface and a straight edge held against the surface.NOTE 2Repairs may be made by epoxying the dislodged aggregateback in place or by filling the void with capping material and allowinga

37、dequate time for it to harden.5.4 Measure the diameter of the test specimen by caliper tothe nearest 0.2 mm 0.01 in. by averaging two diametersmeasured at right angles to each other near the center of thelength of the specimen. Use this average diameter to calculatethe cross-sectional area. Measure

38、and report the length of amolded specimen, including caps, to the nearest 2 mm 0.1 in.Measure the length of a drilled specimen in accordance withTest Method C174/C174M; report the length, including caps,to the nearest 2 mm 0.1 in.6. Procedure6.1 Maintain the ambient temperature and humidity asconsta

39、nt as possible throughout the test. Record any unusualfluctuation in temperature or humidity in the report.6.2 Use companion specimens to determine the compressivestrength in accordance with Test Method C39/C39M prior tothe test for modulus of elasticity.6.3 Place the specimen, with the strain-measu

40、ring equip-ment attached, on the lower platen or bearing block of thetesting machine. Carefully align the axis of the specimen withthe center of thrust of the spherically-seated upper bearingblock. Note the reading on the strain indicators. As thespherically-seated block is brought slowly to bear up

41、on thespecimen, rotate the movable portion of the block gently byhand so that uniform seating is obtained.6.4 Load the specimen at least twice. Do not record any dataduring the first loading. Base calculations on the average of theresults of the subsequent loadings (Note 3).NOTE 3At least two subseq

42、uent loadings are recommended so that therepeatability of the test may be noted.During the first loading, which is primarily for the seating ofthe gauges, observe the performance of the gauges (Note 4)and correct any unusual behavior prior to the second loading.FIG. 3 Suitable Combined Compressomete

43、r-ExtensometerC469/C469M 103Obtain each set of readings as follows: Apply the loadcontinuously and without shock. Set testing machines of thescrew type so that the moving head travels at a rate of about1 mm/min 0.05 in./min when the machine is running idle. Inhydraulically operated machines, apply t

44、he load at a constantrate within the range 250 6 50 kPa/s 35 6 7 psi/s. Record,without interruption of loading, the applied load and longitu-dinal strain at the point (1) when the longitudinal strain is 50millionths and (2) when the applied load is equal to 40 % of theultimate load (see 6.5). Longit

45、udinal strain is defined as thetotal longitudinal deformation divided by the effective gaugelength. If Poissons ratio is to be determined, record thetransverse strain at the same points. If a stress-strain curve is tobe determined, take readings at two or more intermediatepoints without interruption

46、 of loading; or use an instrument thatmakes a continuous record. Immediately upon reaching themaximum load, except on the final loading, reduce the load tozero at the same rate at which it was applied. If the observerfails to obtain a reading, complete the loading cycle and thenrepeat it. Record the

47、 extra cycle in the report.NOTE 4Where a dial gauge is used to measure longitudinal deforma-tion, it is convenient to set the gauge before each loading so that theindicator will pass the zero point at a longitudinal strain of 50 millionths.6.5 It is not prohibited to obtain the modulus of elasticity

48、and strength on the same loading provided that the gauges areexpendable, removable, or adequately protected so that it ispossible to comply with the requirement for continuous loadinggiven in Test Method C39/C39M. In this case record severalreadings and determine the strain value at 40 % of the ulti

49、mateby interpolation.6.6 If intermediate readings are taken, plot the results ofeach of the three tests with the longitudinal strain as theabscissa and the compressive stress as the ordinate. Calculatethe compressive stress by dividing the quotient of the testingmachine load by the cross-sectional area of the specimendetermined in accordance with 5.4.7. Calculation7.1 Calculate the modulus of elasticity, to the nearest200 MPa 50,000 psi as follows:E 5 S22 S1!/22 0.000050! (3)where:E = chord modulus of e