ASTM C469 C469M-2014 Standard Test Method for Static Modulus of Elasticity and Poisson&rsquo s Ratio of Concrete in Compression《压缩混凝土的静态弹性模量和泊松比的标准试验方法》.pdf

《ASTM C469 C469M-2014 Standard Test Method for Static Modulus of Elasticity and Poisson&rsquo s Ratio of Concrete in Compression《压缩混凝土的静态弹性模量和泊松比的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM C469 C469M-2014 Standard Test Method for Static Modulus of Elasticity and Poisson&rsquo s Ratio of Concrete in Compression《压缩混凝土的静态弹性模量和泊松比的标准试验方法》.pdf（6页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: C469/C469M 10C469/C469M 14Standard 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

2、case of revision, 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. Scope Scope*1.1 This test method covers determination of (1) chord modulus of elasticity (Youngs)

3、 and (2) Poissons ratio of moldedconcrete cylinders and diamond-drilled concrete cores when under longitudinal compressive stress. Chord modulus of elasticityand Poissons ratio are defined in Terminology E6.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as

4、 standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.3 This standard does not purport to address all of the safety concerns, if

5、any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C31/C31M Practice for Making and Curing Concrete Te

6、st Specimens in the FieldC39/C39M Test Method for Compressive Strength of Cylindrical Concrete SpecimensC42/C42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of ConcreteC174/C174M Test Method for Measuring Thickness of Concrete Elements Using Drilled Concrete CoresC192/C192M P

7、ractice for Making and Curing Concrete Test 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 Extensomet

8、er SystemsE177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods2.2 ASTM Adjuncts:Compressometers (two drawings) and Extensometers (two drawings)33. Significance and Use3.1 This test method provides a stress to strain ratio value and a ratio of lateral to longitudinal strain for

9、hardened concrete atwhatever age and curing conditions may be designated.3.2 The modulus of elasticity and Poissons ratio values, applicable within the customary working stress range (0 to 40 % ofultimate concrete strength), are used in sizing of reinforced and nonreinforced structural members, esta

10、blishing the quantity ofreinforcement, and computing stress for observed strains.3.3 The modulus of elasticity values obtained will usually be less than moduli derived under rapid load application (dynamicor seismic rates, for example), and will usually be greater than values under slow load applica

11、tion or extended load duration, givenother test conditions being the same.1 This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.61 onTesting for Strength.Current edition approved Oct. 1, 2010March 1

12、, 2014. Published November 2010April 2014. Originally approved in 1961. Last previous edition approved in 20022010as C469C469 0210.1 . DOI: 10.1520/C0469_C0469M-10.10.1520/C0469_C0469M-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at servicea

13、stm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from ASTM International Headquarters. Order Adjunct No. ADJC0469.This document is not an ASTM standard and is intended only to provide the user of an ASTM standa

14、rd an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM

15、is to be considered the official document.*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. Apparatus4.1 Testing MachineUse a testing machine capable of imposing a load

16、 at the rate and of the magnitude prescribed in 6.4. Themachine shall conform to the requirements of Practices E4 (Constant-Rate of-Traverse CRT-Type Testing Machines section). Thespherical head and bearing blocks shall conform to the Apparatus Section of Test Method C39/C39M.4.2 Compressometer3For

17、determining the modulus of elasticity use a bonded (Note 1) or unbonded sensing device thatmeasures to the nearest 5 millionths the average deformation of two diametrically opposite gauge lines, each parallel to the axis,and each centered about midheight of the specimen. The effective length of each

18、 gauge line shall be not less than three times themaximum size of the aggregate in the concrete nor more than two thirds the height of the specimen; the preferred length of thegauge line is one half the height of the specimen. Either use gauge points embedded in or cemented to the specimen, and read

19、deformation of the two lines independently; or use a compressometer (such as is shown in Fig. 1) consisting of two yokes, oneof which (see B,Fig. 1) is rigidly attached to the specimen and the other (see C,Fig. 1) attached at two diametrically opposite pointsso that it is free to rotate. At one poin

20、t on the circumference of the rotating yoke, midway between the two support points, use apivot rod (see A,Fig. 1) to maintain a constant distance between the two yokes. At the opposite point on the circumference of therotating yoke, the change in distance between the yokes (that is, the gauge readin

21、g) is equal to the sum of the displacement dueto specimen deformation and the displacement due to rotation of the yoke about the pivot rod (see Fig. 2).4.2.1 Measure deformation by a dial gauge used directly or with a lever multiplying system, by a wire strain gauge, or by alinear variable different

22、ial transformer. If the distances of the pivot rod and the gauge from the vertical plane passing through thesupport points of the rotating yoke are equal, the deformation of the specimen is equal to one-half the gauge reading. If thesedistances are not equal, calculate the deformation as follows:d 5

23、ge r/er1eg! (1)where:d = total deformation of the specimen throughout the effective gauge length, m in.,FIG. 1 Suitable CompressometerC469/C469M 142g = gauge reading, m in.,er = the perpendicular distance, measured to the nearest 0.2 mm 0.01 in. from the pivot rod to the vertical plane passingthroug

24、h the two support points of the rotating yoke, andeg = the perpendicular distance, measured to the nearest 0.2 mm 0.01 in. from the gauge to the vertical plane passing throughthe two support points of the rotating yoke.Procedures for calibrating strain-measuring devices are given in Practice E83.NOT

25、E 1Although bonded strain gauges are satisfactory on dry specimens, they may be difficult, if not impossible, to mount on specimens continuallymoist-cured until tested.4.3 Extensometer3If Poissons ratio is desired, the transverse strain shall be determined (1) by an unbonded extensometercapable of m

26、easuring to the nearest 0.5 m 25 in. the change in diameter at the midheight of the specimen, or (2) by two bondedstrain gauges (Note 1) mounted circumferentially at diametrically opposite points at the midheight of the specimen and capableof measuring circumferential strain to the nearest 5 million

27、ths. A combined compressometer and extensometer (Fig. 3) is aconvenient unbonded device. This apparatus shall contain a third yoke (consisting of two equal segments) located halfway betweenthe two compressometer yokes and attached to the specimen at two diametrically opposite points. Midway between

28、these pointsuse a short pivot rod (A, see Fig. 3), adjacent to the long pivot rod, to maintain a constant distance between the bottom and middleyokes. Hinge the middle yoke at the pivot point to permit rotation of the two segments of the yoke in the horizontal plane. At theopposite point on the circ

29、umference, connect the two segments through a dial gauge or other sensing device capable of measuringtransverse deformation to the nearest 1.27 m 50 in. If the distances of the hinge and the gauge from the vertical plane passingthrough the support points of the middle yoke are equal, the transverse

30、deformation of the specimen diameter is equal to one-halfthe gauge reading. If these distances are not equal, calculate the transverse deformation of the specimen diameter in accordancewith Eq 2.d5ge h/eh1eg! (2)where:d = transverse deformation of the specimen diameter, m in.,g = transverse gauge re

31、ading, m in.,eh = the perpendicular distance, measured to the nearest 0.2 mm 0.01 in. from the hinge to the vertical plane passing throughthe support points of the middle yoke, andeg = the perpendicular distance, measured to the nearest 0.2 mm 0.01 in. from the gauge to the vertical plane passing th

32、roughthe support points of the middle yoke.4.4 Balance or Scale, accurate to 50 g 0.1 lb shall be used if necessary.5. Test Specimens5.1 Molded Cylindrical SpecimensMold test cylinders in accordance with the requirements for compression test specimensin Practice C192/C192M, or in Practice C31/C31M.

33、Subject specimens to the specified curing conditions and test at the age forwhich the elasticity information is desired. Test specimens within 1 h after removal from the curing or storage room. Specimensremoved from a moist room for test shall be kept moist by a wet cloth covering during the interva

34、l between removal and test.d = 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 1435.2 Drilled Core Sp

35、ecimensCores shall comply with the requirements for drilling, and moisture conditioning applicable tocompressive strength specimens in Test Method C42/C42M, except that only diamond-drilled cores having a length-to-diameterratio greater than 1.50 shall be used. Requirements relative to storage and t

36、o ambient conditions immediately prior to test shall bethe same as for molded cylindrical specimens.5.3 The ends of the test specimens shall be made perpendicular to the axis60.001 rad 60.5 and plane within 0.05 mm 0.002in. If the specimen as cast does not meet the planeness requirements, planeness

37、shall be accomplished by capping in accordancewith Practice C617, or by lapping, or by grinding. It is not prohibited to repair aggregate popouts that occur at the ends ofspecimens, provided the total area of popouts does not exceed 10 % of the specimen area and the repairs are made before cappingor

38、 grinding is completed (Note 2). Planeness will be considered within tolerance when a 0.05 mm 0.002 in. feeler gauge will notpass between the specimen surface and a straight edge held against the surface.NOTE 2Repairs may be made by epoxying the dislodged aggregate back in place or by filling the vo

39、id with capping material and allowing adequatetime for it to harden.5.4 Measure the diameter of the test specimen by caliper to the nearest 0.2 mm 0.01 in. by averaging two diameters measuredat right angles to each other near the center of the length of the specimen. Use this average diameter to cal

40、culate the cross-sectionalarea. Measure and report the length of a molded specimen, including caps, to the nearest 2 mm 0.1 in. Measure the length ofa drilled specimen in accordance with Test Method C174/C174M; report the length, including caps, to the nearest 2 mm 0.1 in.6. Procedure6.1 Maintain th

41、e ambient temperature and humidity as constant as possible throughout the test. Record any unusual fluctuationin temperature or humidity in the report.The temperature surrounding the specimen shall not vary by more than 2C 4F duringa test.6.2 Use Except as provided in 6.5, use at least two companion

42、 specimens to determine the compressive strength in accordancewith Test Method C39/C39M prior to the test for modulus of elasticity.6.3 Place the specimen, with the strain-measuring equipment attached, on the lower platen or bearing block of the testingmachine. Carefully align the axis of the specim

43、en with the center of thrust of the spherically-seated upper bearing block. Note thereading on the strain indicators.As the spherically-seated block is brought slowly to bear upon the specimen, rotateBefore applyingFIG. 3 Suitable Combined Compressometer-ExtensometerC469/C469M 144the load on the spe

44、cimen, tilt the movable portion of the spherically seated block gently by hand so that uniform seating isobtained.the bearing face appears to be parallel to the top of the test specimen based on visual observation.6.4 Load the specimen at least twice. three times. Do not record any data during the f

45、irst loading. Base calculations on theaverage of the results of the subsequent loadings (loadings. Note 3).NOTE 3At least two subsequent loadings are recommended so that the repeatability of the test may be noted.6.4.1 Apply the load continuously and without shock. Set testing machines of the screw

46、type so that the moving head travelsat a rate of about1 mm/min 0.05 in./min when the machine is running idle. In hydraulically operated machines, apply the load at a constant ratewithin the range 250 6 50 kPa/s 35 6 7 psi/s. Load the specimen until the applied load is 40 % of the average ultimate lo

47、adof the companion specimens. This is the maximum load for the modulus of elasticity test.During the first loading, which is primarily for the seating of the gauges, observe the performance of the gauges (Note 4) andcorrect any unusual behavior prior to the second loading. Obtain each set of reading

48、s as follows: Apply the load continuously andwithout shock. Set testing machines of the screw type so that the moving head travels at a rate of about1 mm/min 0.05 in./min when the machine is running idle. In hydraulically operated machines, apply the load at a constant ratewithin the range 250 6 50

49、kPa/s 35 6 7 psi/s. Record, without interruption of loading, the applied load and longitudinal strainat the point (1) when the longitudinal strain is 50 millionths and (2) when the applied load is equal to 40 % of the ultimate load(see 6.5). Longitudinal strain is defined as the total longitudinal deformation divided by the effective gauge length. If Poissonsratio is to be determined, record the transverse strain at the same points. If a stress-strain curve is to be determined, take rea