1、Designation: D7617/D7617M 11Standard 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 or, in the case of
2、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 round rods and textur
3、ed 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, for example.1.2 T
4、he 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-conformancewith the s
5、tandard.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 practices and determine
6、the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A615/A615M Specification for Deformed and PlainCarbon-Steel Bars for Concrete ReinforcementD883 Terminology Relating to PlasticsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for M
7、oisture AbsorptionProperties and Equilibrium Conditioning of Polymer Ma-trix Composite MaterialsD7205/D7205M Test Method for Tensile Properties of Fi-ber Reinforced Polymer Matrix Composite BarsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical Te
8、stingE122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE456 Terminology Relating to Quality and Statistics3. Terminology3.1 Terminology in D3878 defines terms relating to high-modulus fibers and their composites. Termin
9、ology 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 inD3878 shall have precedence over the other
10、 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 shear fixture, na test fixture that res
11、ults 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, na measure of crosssectional area of a
12、 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 throughwithout undue force.3.2.6 rod, na b
13、ar with a smooth circular cross section andno texture or deformations.3.2.7 standard cross sectional area, nthe cross sectionalarea of a standard numbered steel concrete reinforcing bar asgiven in A615/A615M, Table 1.3.2.8 surface undulation, nvariation in the area, orienta-tion, or shape of cross s
14、ection of a bar along its length, intendedto enhance mechanical interlock between a bar and concrete,made by any of a number of processes such as, for example,indentation, addition of extra materials, and twisting.1This test method is under the jurisdiction of ASTM Committee D30 onComposite Material
15、s and is the direct responsibility of Subcommittee D30.05 onStructural Test Methods.Current edition approved March 1, 2011. Published May 2011. DOI: 10.1520/D7617_D7617M-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For A
16、nnual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.3 Symbols:3.3.1 Anominal or standard cross sectional area of a rodor ba
17、r, see D7205/D7205M.3.3.2 PSmaximum shear force carried by specimen Nlbf.3.3.3 tutransverse shear strength, MPa psi.4. Summary of Test Method4.1 A length of fiber-reinforced polymer (FRP) rod or bar isfitted into a double shear fixture with appropriate cutting bladesand clamped into place. The shear
18、 fixture is mounted into auniversal mechanical testing machine and monotonicallyloaded to failure while recording force and crosshead displace-ment.5. Significance and Use5.1 This test method for transverse shear strength is in-tended for use in laboratory tests in which the principalvariable is the
19、 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 Portland cementconcrete. This test method establishes values of transverseshear strength for material specifications, quality control,quality assu
20、rance, research and development, and may also beused for structural design purposes.5.2 Experience with this test method and the accompanyingfixture is primarily 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 la
21、rger diameters, butthe overall geometry of the test fixture may need to beincreased.6. Interferences6.1 Blade AlignmentThe two lower and one upper bladeused for shearing the specimen are machined to fit theprojected outer diameter of the bar. The slot width and diameterof the blades should be select
22、ed 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 texture 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%vari
23、ation in diameter relative to the average bar diameter asmeasured with a dial caliper. Use on bars with greater variationin surface roughness or regions with substantially-reducedcross-sections may lead to increased scatter in test results orfailure of the specimens away from the two shearing planes
24、.6.3 Measurement 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
25、porosity) cannot be assessed using this method. ThisNOTEThe blades should fit snugly around the bar without binding.FIG. 1 Potential Interference for Undulating or Textured BarD7617/D7617M 112method may not be appropriate for bars that have largevariations in cross sectional area along the length of
26、 the bar.6.4 Clamping ForceThe bar should be firmly clamped tothe bar seats before testing. Testing without sufficient clampingwill lead to lower apparent transverse shear strength results.Experience with the fixture and small-diameter glass-reinforced FRP rods has shown that two set screws on one e
27、ndof the bar and one set screw on the other end is sufficient forthis clamping.6.5 System AlignmentThe test is typically completed onuniversal testing machine with compression platens. Careshould be taken that bottom compression platen is completelyflat and large enough for entire surface of test fi
28、xture 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 guides machined from steel. These parts arebolted together with two threaded rods with washers and nutsas shown in Figs. 2 and 3. Thin shim stock (suggestedt
29、hickness 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 lower 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 fixt
30、ure 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 allow for insertion of thelower blades. These fixtures are acceptable for use with this standard butthe fit between the lower and upper blades is not adjus
31、table.7.2 Dimensional TolerancesDimensional tolerances forthe components of the test fixture produced in U.S. customaryunits shall be standard tolerances as follows: Unless notedotherwise on the drawings, dimensions given to one decimalplace (0.X in.) shall be 60.05 in., dimensions given to twodecim
32、al places (0.0X in.) shall be 60.01 in., and dimensionsgiven to three decimal places (0.00X in.) shall be 60.005 in.For components produced in SI units, standard tolerances forFIG. 2 Transverse Shear Fixture Assembled (Side Views and Axonometric View)D7617/D7617M 113dimensions given to zero decimal
33、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 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 lo
34、wer blades and upper blade should bemachined from tool steel, hardened to 55 to 58 HRC.7.4.1 Lower BladesThe two lower blades are machinedfrom 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 th
35、e 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 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 t
36、he 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).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
37、samemachined slot and diameter as the two lower blades (see Fig.7a and b).NOTE 2This standard does not give specific dimensional require-ments for the slots and diameters of the lower and upper blades, as a widerange of textured bars and smooth rods, produced under both SI and USCustomary standards,
38、 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.S. practice, blades for the apparatus are typically madefor smooth and textured rods in diameters that range between 6 mm (0.25in.) to 25 mm (1 in.).7.5 Guides
39、The 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 theNOTE(1) Assembled fixture with sheared specimen and (2) main body of fixture disassembled (note presence of shim stock on guides).FI
40、G. 3 Photographs of Test FixtureD7617/D7617M 114upper blade into the fixture. The holes in the guides align withthe holes in the lower 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 t
41、op of both bar seats, are used to clamp the baror rod firmly into the bar seats during testing. Socket-head capscrews pass through threads in the straps and clamp thespecimens onto the bar seats. (see Fig. 8a and b).7.7 Testing MachineThe testing machine shall be inconformance with Practices E4 and
42、shall satisfy the followingrequirements:7.7.1 Testing Machine HeadsThe testing machine shallhave both an essentially stationary head 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
43、 imparting to the movable head acontrolled velocity with respect to the stationary head. Thevelocity of the movable head shall be 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
44、 the test specimen. This device shall be essentiallyfree from inertia lag at the specified rate of testing and shallindicate the force 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,mu
45、ch higher for strength evaluation, or both, as required.8. Sampling 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 fiv
46、e specimens per test condi-tion unless valid results can be gained through the use of fewerFIG. 4 a Bar Seat (U.S. Customary Units)D7617/D7617M 115specimens, such as in the case of a designed experiment. Forstatistically significant data, the procedures outlined in E122should be consulted. The metho
47、d 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
48、 round rods shallbe determined by measuring the average diameter of the rod toa precision of 0.02 mm 0.001 in. and calculating the area ofthe rod assuming that it is circular.9. Calibration9.1 The accuracy of all measuring equipment shall havecertified calibrations that are current at the time of us
49、e of theequipment.10. Conditioning10.1 The recommended pre-test condition is effective mois-ture equilibrium at a specific relative humidity as establishedby Test Method D5229/D5229M; however, if the test requestordoes not explicitly specify a pre-test conditioning environment,no conditioning is required and the specimens may be tested asprepared.10.2 The pre-test specimen conditioning process, to includespecified environmental exposure levels and resulting moisturecontent, shall be reported with the test data.10.3
