ASTM D7617D7617M-11(2017) Standard Test Method for Transverse Shear Strength of Fiber-reinforced Polymer Matrix Composite Bars.pdf

1、Designation: D7617/D7617M 11 (Reapproved 2017)Standard Test Method forTransverse Shear Strength of Fiber-reinforced PolymerMatrix Composite Bars1This standard is issued under the fixed designation D7617/D7617M; the number immediately following the designation indicates theyear of original adoption o

2、r, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method specifies the test requirements for(FRP) composite smooth rou

3、nd rods and textured bars fordetermining the transverse shear strength via a double shearfixture. FRP rods and bars are often loaded in transverse shearwhen these elements are used as dowels in concrete pavements,as stirrups in concrete beams, or as shear reinforcements inglued-laminated wood beams,

4、 for example.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated 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-con

5、formancewith the standard.1.2.1 Within the text, the inch-pound units are shown inbrackets.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 practi

6、ces and determine the applica-bility of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and

7、Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A615/A615M Specification for Deformed and Plain Carbon-Steel Bars for Concrete ReinforcementD883 Terminology Relating to PlasticsD3878 Terminology for Composi

8、te MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite MaterialsD7205/D7205M Test Method for Tensile Properties of FiberReinforced Polymer Matrix Composite BarsE4 Practices for Force Verification of Testing MachinesE6 Terminolo

9、gy Relating to Methods of Mechanical TestingE122 Practice for Calculating Sample Size to Estimate, WithSpecified Precision, the Average for a Characteristic of aLot or ProcessE456 Terminology Relating to Quality and Statistics3. Terminology3.1 Terminology in D3878 defines terms relating to high-modu

10、lus fibers and their composites. Terminology in D883defines terms relating to plastics. Terminology in E6 definesterms relating to mechanical testing. Terminology in E456defines terms relating to statistics and the selection of samplesizes. In the event of a conflict between terms, Terminology inD38

11、78 shall have precedence over the other terminologystandards.3.2 Definitions of Terms Specific to This Standard:3.2.1 bar, na linear element, with a substantially roundcross section, often with surface undulations or a coating ofparticles that promote mechanical interlock with concrete.3.2.2 double

12、shear fixture, na test fixture that results in thedesired shear force being applied to two distinct sections of thespecimen.3.2.3 failure, ncleavage of the bar under test into threepieces or into two pieces where the second non-cleaved shearplane is highly damaged.3.2.4 nominal cross sectional area,

13、 na measure of crosssectional area of a bar, determined over at least one represen-tative length, used to calculate stress.3.2.5 projected outer diameter, nthe smallest diameter ofa circle through which a bar, with its undulations or coatings,will pass. The bar may touch the circle but must pass thr

14、oughwithout undue force.1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.10 onComposites for Civil Structures.Current edition approved Aug. 1, 2017. Published September 2017. Originallyapproved in 2011. Last

15、previous edition approved as D7617/D7617M11. DOI:10.1520/D7617_D7617M-11R17.2For 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 onth

16、e ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevel

17、opment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2.6 rod, na bar with a smooth circular cross section andno texture or deformations.3.2.7 standard cross sectional area, nthe cross sectionalarea of a st

18、andard numbered steel concrete reinforcing bar asgiven in A615/A615M, Table 1.3.2.8 surface undulation, nvariation in the area,orientation, or shape of cross section of a bar along its length,intended to enhance mechanical interlock between a bar andconcrete, made by any of a number of processes suc

19、h as, forexample, indentation, addition of extra materials, and twisting.3.3 Symbols:3.3.1 Anominal or standard cross sectional area of a rod orbar, see D7205/D7205M.3.3.2 PSmaximum shear force carried by specimen Nlbf.3.3.3 utransverse shear strength, MPa psi.4. Summary of Test Method4.1 A length o

20、f fiber-reinforced polymer (FRP) rod or bar isfitted into a double shear fixture with appropriate cutting bladesand clamped into place. The shear fixture is mounted into auniversal mechanical testing machine and monotonicallyloaded to failure while recording force and crosshead displace-ment.5. Sign

21、ificance and Use5.1 This test method for transverse shear strength is in-tended for use in laboratory tests in which the principalvariable is the size or type of FRP bars. The test may be usedfor smooth round rods or on bars with a textured or undulatingsurface added to promote bond of the bars to P

22、ortland cementconcrete. This test method establishes values of transverseshear strength for material specifications, quality control,quality assurance, research and development, and may also beused for structural design purposes.5.2 Experience with this test method and the accompanyingfixture is pri

23、marily with smooth rods and textured bars withdiameters ranging from 6 mm to 25 mm 0.25 in. to 1 in. Themethod may be used for rods or bars of larger diameters, butthe overall geometry of the test fixture may need to beincreased.6. Interferences6.1 Blade AlignmentThe two lower and one upper bladeuse

24、d for shearing the specimen are machined to fit theprojected outer diameter of the bar. The slot width and diameterof the blades should be selected so that the bar fits snugly intothe fixture, but does not bind. The test results may be sensitiveto the slot width for bars which have significant textu

25、re ordeformations. See Fig. 1.6.2 Surface TextureThe method has been used with tex-tured bars with surface roughness amplitudes of up to 6 5%variation in diameter relative to the average bar diameter asmeasured with a dial caliper. Use on bars with greater variationin surface roughness or regions wi

26、th substantially-reducedcross-sections may lead to increased scatter in test results orfailure of the specimens away from the two shearing planes.NOTE 1The blades should fit snugly around the bar without binding.FIG. 1 Potential Interference for Undulating or Textured BarD7617/D7617M 11 (2017)26.3 M

27、easurement of Cross Sectional AreaThe nominalcross sectional area of textured or undulating bars is measuredby immersing a prescribed length of the specimen in water todetermine its buoyant weight, as described in D7205/D7205M.Bar configurations that trap air during immersion (aside fromminor porosi

28、ty) cannot be assessed using this method. Thismethod may not be appropriate for bars that have largevariations in cross sectional area along the length of the bar.6.4 Clamping ForceThe bar should be firmly clamped tothe bar seats before testing. Testing without sufficient clampingwill lead to lower

29、apparent transverse shear strength results.Experience with the fixture and small-diameter glass-reinforced FRP rods has shown that two set screws on one endof the bar and one set screw on the other end is sufficient forthis clamping.6.5 System AlignmentThe test is typically completed onuniversal tes

30、ting machine with compression platens. Careshould be taken that bottom compression platen is completelyflat and large enough for entire surface of test fixture to bear,and is perpendicular to the axis of loading.7. Apparatus7.1 The test fixture consists of two bar seats, two lowerblades, and two gui

31、des machined from steel. These parts arebolted together with two threaded rods with washers and nutsas shown in Figs. 2 and 3. Thin shim stock (suggestedthickness of 0.08 mm 0.003 in.) may be placed between thebar seats and the guides to ensure a close running fit of theupper blade between the two l

32、ower blades (see Fig. 5a and band Fig. 6a and b). The upper blade is loose, and is fit onto thebar prior to testing.NOTE 1Other versions of this test fixture have been developed thatcombine the two lower bar seats into one unified component with a fixedgap of 50 mm 2.0 in. between the bar seats to a

33、llow for insertion of thelower blades. These fixtures are acceptable for use with this standard butthe fit between the lower and upper blades is not adjustable.7.2 Dimensional TolerancesDimensional tolerances forthe components of the test fixture produced in U.S. customaryunits shall be standard tol

34、erances as follows: Unless notedotherwise on the drawings, dimensions given to one decimalplace (0.X in.) shall be 60.05 in., dimensions given to twoFIG. 2 Transverse Shear Fixture Assembled (Side Views and Axonometric View)D7617/D7617M 11 (2017)3decimal places (0.0X in.) shall be 60.01 in., and dim

35、ensionsgiven to three decimal places (0.00X in.) shall be 60.005 in.For components produced in SI units, standard tolerances fordimensions given to zero decimal places (X mm) shall be 60.1mm, dimensions given to one decimal place (0.X mm) shall be60.25 mm, dimension given to two decimal places (0.0X

36、 mm)shall be 60.10 mm.7.3 Bar SeatsThe two bar seats are identical and have av-shaped bed for supporting the ends of the bars (see Fig. 4aand b).7.4 BladesThe lower blades and upper blade should bemachined from tool steel, hardened to 55 to 58 HRC.7.4.1 Lower BladesThe two lower blades are machinedf

37、rom 12 mm 0.500 in. thick steel having a precision groundfinish of 0.80 m 32 in. or better. The slots in the lowerblades are machined based on the diameter of the bars to betested. For smooth round rods, the width of the slot shall be0.10 mm 0.004 in. wider than the measured diameter of therods. For

38、 textured or undulating bars the slot shall be equal tothe projected outer diameter from the roughly circular bar. Thedepth of the semi-circle at the bottom of the slot shall beestablished so that the diameter of the semi-circle is tangentwith the angled side of the bar seat (see Fig. 1 and Fig. 5).

39、7.4.2 Upper BladeThe upper blade is machined from 25mm 1.000 in. thick steel having a precision ground finish of0.80 m 32 in. or better. The upper blade has the samemachined slot and diameter as the two lower blades (see Fig.7a and b).NOTE 2This standard does not give specific dimensional requiremen

40、tsfor the slots and diameters of the lower and upper blades, as a wide rangeof textured bars and smooth rods, produced under both SI and USCustomary standards, may be tested using this method. Fig. 5 and Fig. 7depict the dimensions of lower and upper blades for a 3/8 in. and a 10 mmsmooth rod. In U.

41、S. practice, blades for the apparatus are typically madeNOTE 1(1) Assembled fixture with sheared specimen and (2) main body of fixture disassembled (note presence of shim stock on guides).FIG. 3 Photographs of Test FixtureD7617/D7617M 11 (2017)4for smooth and textured rods in diameters that range be

42、tween 6 mm (0.25in.) to 25 mm (1 in.).7.5 GuidesThe guides are machined from the same steelas the upper blade. The two guides are of equal thickness to theupper blade and may be tapered to facilitate insertion of theupper blade into the fixture. The holes in the guides align withthe holes in the low

43、er blades and in the bar seats so that theentire assembly can be bolted together (see Fig. 6a and b).7.6 StrapStraps, nominally 12 mm 0.5 in. thick, andmounted at the top of both bar seats, are used to clamp the baror rod firmly into the bar seats during testing. Socket-head capscrews pass through t

44、hreads in the straps and clamp thespecimens onto the bar seats. (see Fig. 8a and b).7.7 Testing MachineThe testing machine shall be in con-formance with Practices E4 and shall satisfy the followingrequirements:7.7.1 Testing Machine HeadsThe testing machine shallhave both an essentially stationary he

45、ad and a movable head.The movable head shall be equipped with a deflection measur-ing device.7.7.2 Drive MechanismThe testing machine drive mecha-nism shall be capable of imparting to the movable head acontrolled velocity with respect to the stationary head. Thevelocity of the movable head shall be

46、capable of beingregulated as specified in 11.4.7.7.3 Force IndicatorThe testing machine force-sensingdevice shall be capable of indicating the total force beingcarried by the test specimen. This device shall be essentiallyfree from inertia lag at the specified rate of testing and shallindicate the f

47、orce with an accuracy over the force range(s) ofinterest of within 6 1 % of the indicated value. The forcerange(s) of interest may be fairly low for modulus evaluation,much higher for strength evaluation, or both, as required.FIG. 4 a Bar Seat (U.S. Customary Units)D7617/D7617M 11 (2017)58. Sampling

48、 and Test Specimens8.1 Specimens shall be representative of the lot or batchbeing tested. In the test section of the specimen, no postpro-duction machining, abrading, or other such processing ispermitted.8.2 SamplingTest at least five specimens per test condi-tion unless valid results can be gained

49、through the use of fewerspecimens, such as in the case of a designed experiment. Forstatistically significant data, the procedures outlined in E122should be consulted. The method of sampling shall be reported.8.3 The length of the specimen shall be 225 mm 9 in.8.4 The cross sectional area of textured or undulating barsshall be determined in accordance with either of the twomethods described in D7205/D7205M: nominal area or stan-dard area. The cross sectional area of smooth round rods shallbe