1、Designation: C 469 02e1Standard Test Method forStatic Modulus of Elasticity and Poissons Ratio of Concretein Compression1This standard is issued under the fixed designation C 469; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEAdjunct references were corrected editorially in April 2006.1. Scope1.1 This test method covers determination of (
3、1) chordmodulus of elasticity (Youngs) and (2) Poissons ratio 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 inch-pound units are to be rega
4、rdedas 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-bility of regulatory limitations prior to
5、 use.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 Method for Obtaining and Testing DrilledCores and Sawed Beams of ConcreteC 17
6、4/C 174M Test Method for Measuring Thickness ofConcrete Elements Using Drilled Concrete CoresC 192/C 192M Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC 617 Practice for Capping Cylindrical Concrete Speci-mensE4 Practices for Force Verification of Testing MachinesE6 Termino
7、logy Relating to Methods of Mechanical Test-ingE83 Practice for Verification and Classification of Exten-someter SystemE 177 Practice for Use of the Terms Precision and Bias inASTM Test Methods2.2 ASTM Adjuncts:Compressometers (two drawings) and Extensometers (twodrawings)33. Significance and Use3.1
8、 This test method provides a stress to strain ratio valueand a ratio of lateral to longitudinal strain for hardenedconcrete at whatever 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
9、 ultimate concrete strength), are used in sizing ofreinforced and nonreinforced structural members, establishingthe quantity of reinforcement, 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
10、(dynamic or seismic rates, for example), and will usually begreater than values under slow load application or extendedload duration, given 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
11、in6.4. The machine shall conform to the requirements of Prac-tices E4(Constant-Rate of-Traverse CRT-Type Testing Ma-chines section). The spherical head and bearing blocks shallconform to theApparatus Section of Test Method C 39/C 39M.4.2 Compressometer3For determining the modulus ofelasticity use a
12、bonded (Note 1) or unbonded sensing devicethat measures to the nearest 5 millionths the average deforma-tion of two diametrically opposite gage lines, each parallel tothe axis, and each centered about midheight of the specimen.1This test method is under the jurisdiction of ASTM Committee C09 onConcr
13、ete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.61 on Testing for Strength.Current edition approved Aug. 10, 2002. Published October 2002. Originallyapproved in 1961. Last previous edition approved in 1994 as C469 94e1.2For referenced ASTM standards, visit the ASTM we
14、bsite, 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 Headquarters. Order Adjunct No.ADJC0469.1Copyright ASTM International, 100
15、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.The effective length of each gage 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; thepreferred length of the gage line is one h
16、alf the height of thespecimen. Either use gage points embedded in or cemented tothe specimen, and read 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 oth
17、er (see C, Fig. 1) attachedat two diametrically opposite points so that it is free to rotate.At one point 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
18、 circumference of the rotating yoke,the change in distance between the yokes (that is, the gagereading) 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 gage used di
19、rectly orwith a lever multiplying system, by a wire strain gage, or by alinear variable differential transformer. If the distances of thepivot rod and the gage from the vertical plane passing throughthe support points of the rotating yoke are equal, the deforma-tion of the specimen is equal to one-h
20、alf the gage reading. Ifthese distances are not equal, calculate the deformation asfollows:d 5 ger/er1 eg! (1)where:d = total deformation of the specimen throughout theeffective gage length, in. (m),g = gage reading, in. (m),er= the perpendicular distance, measured in inches (mil-limetres) to the ne
21、arest 0.01 in. (0.254 mm) from thepivot rod to the vertical plane passing through the twosupport points of the rotating yoke, andeg= the perpendicular distance, measured in inches (milli-metres) to the nearest 0.01 in. (0.254 mm) from thegage to the vertical plane passing through the twosupport poin
22、ts of the rotating yoke.Procedures for calibrating strain-measuring devices aregiven in Practice E83.NOTE 1Although bonded strain gages are satisfactory on dry speci-mens, they may be difficult, if not impossible, to mount on specimenscontinually moist-cured until tested.4.3 Extensometer3If Poissons
23、 ratio is desired, the trans-verse strain shall be determined (1) by an unbonded extensom-eter capable of measuring to the nearest 25 in. (0.635 m) thechange in diameter at the midheight of the specimen, or (2)bytwo bonded strain gages (Note 1) mounted circumferentially atdiametrically opposite poin
24、ts at the midheight of the specimenand capable of measuring circumferential strain to the nearest5 millionths. A combined compressometer and extensometer(Fig. 3) is a convenient unbonded device. This apparatus shallcontain a third yoke (consisting of two equal segments) locatedhalfway between the tw
25、o compressometer yokes and attachedto the specimen at two diametrically opposite points. Midwaybetween these points use a short pivot rod ( A8, see Fig. 3),adjacent to the long pivot rod, to maintain a constant distancebetween the bottom and middle yokes. Hinge the middle yokeat the pivot point to p
26、ermit rotation of the two segments of theyoke in the horizontal plane. At the opposite point on theFIG. 1 Suitable Compressometerd = displacement due to specimen deformationr = displacement due to rotation of the yoke about the pivot roda = location of gageb = support point of the rotating yokec = l
27、ocation of pivot rodg = gage readingFIG. 2 Diagram of DisplacementsC46902e12circumference, connect the two segments through a dial gageor other sensing device capable of measuring transversedeformation to the nearest 50 in. (1.27 m). If the distances ofthe hinge and the gage from the vertical plane
28、passing throughthe support points of the middle yoke are equal, the transversedeformation of the specimen diameter is equal to one-half thegage reading. If these distances are not equal, calculate thetransverse deformation of the specimen diameter in accordancewith Eq 2.d8 5 g8e8h/e8h1 e8g! (2)where
29、:d8 = transverse deformation of the specimen diameter, in.(m),g8 = transverse gage reading, in. (m),e8h= the perpendicular distance, measured in inches (mil-limeters) to the nearest 0.01 in. (0.254 mm) from thehinge to the vertical plane passing through the sup-port points of the middle yoke, ande8g
30、= the perpendicular distance, measured in inches (mil-limeters) to the nearest 0.01 in. (0.254 mm) from thegage to the vertical plane passing through the supportpoints of the middle yoke.4.4 Balance or Scale, accurate to 0.1 lb (0.045 kg) shall beused if necessary.5. Test Specimens5.1 Molded Cylindr
31、ical SpecimensMold test cylinders inaccordance with the requirements for compression test speci-mens in Practice C 192/C 192M, or in Practice C 31/C 31M.Subject specimens to the specified curing conditions and test atthe age for which the elasticity information is desired. Testspecimens within 1 h a
32、fter 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 therequirements for drilling, and moisture conditioning applicableto comp
33、ressive strength specimens in Test Method C 42/C 42M, except that only diamond-drilled cores having alength-to-diameter ratio greater than 1.50 shall be used. Re-quirements relative to storage and to ambient conditionsimmediately prior to test shall be the same as for moldedcylindrical specimens.5.3
34、 The ends of the test specimens shall be made perpen-dicular to the axis (6 0.5) and plane (within 0.002 in.). If thespecimen as cast does not meet the planeness requirements,planeness shall be accomplished by capping in accordance withPractice C 617, or by lapping, or by grinding. It is notprohibit
35、ed to repair aggregate popouts that occur at the ends ofspecimens, provided the total area of popouts does not exceed10 % of the specimen area and the repairs are made beforecapping or grinding is completed (Note 2). Planeness will beconsidered within tolerance when a 0.002 in. (0.05 mm) feelergage
36、will not pass between the specimen surface and a straightedge 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 allowingadequate time for it to harden.5.4 Measure the diameter of the test specimen by c
37、aliper tothe nearest 0.01 in. (0.25 mm) 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 and report the length of amolded specimen, including caps, to the nearest 0.1
38、 in. (2.54mm). Measure the length of a drilled specimen in accordancewith Test Method C 174/C 174M; report the length, includingcaps, to the nearest 0.1 in. (2.54 mm).6. Procedure6.1 Maintain the ambient temperature and humidity asconstant as possible throughout the test. Record any unusualfluctuati
39、on in temperature or humidity in the report.6.2 Use companion specimens to determine the compressivestrength in accordance with Test Method C 39/C 39M prior tothe test for modulus of elasticity.6.3 Place the specimen, with the strain-measuring equip-ment attached, on the lower platen or bearing bloc
40、k 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 upon thespecimen, rotate the movable portion of the block gentl
41、y 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).FIG. 3 Suitable Combined Compressometer-ExtensometerC46902e13NOTE 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 gages, observe the performance of the gages (Note 4) andcorrect any unusual behavior prior to the second loading.Obtain each set of readings as follows:
43、Apply the loadcontinuously and without shock. Set testing machines of thescrew type so that the moving head travels at a rate of about0.05 in. (1.25 mm)/min when the machine is running idle. Inhydraulically operated machines, apply the load at a constantrate within the range 35 6 5 psi (241 6 34 kPa
44、)/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). Longitudinal strain is defined as thetotal longitudinal deformation divid
45、ed by the effective gagelength. 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 of loading; or use an instrument thatmakes a continuous record. Imm
46、ediately 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 extra cycle in the report.NOTE 4Where a dial gage is used to measur
47、e longitudinal deforma-tion, it is convenient to set the gage 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 elasticityand strength on the same loading provided that the gages areexpendable
48、, removable, or adequately protected so that it ispossible to comply with the requirement for continuous loadinggiven in Test Method C 39/C 39M. In this case record severalreadings and determine the strain value at 40 % of the ultimateby interpolation.6.6 If intermediate readings are taken, plot the
49、 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 nearest50 000 psi (344.74 MPa) as follows:E 5 S22 S1!/e22 0.000050! (3)where:E = chord modulus of elasticity, psi,S2= stress corresponding to 40 % of ultimate load,S1= stress corresponding to a longitudinal str
