1、Designation: D7565/D7565M 10Standard Test Method forDetermining Tensile Properties of Fiber Reinforced PolymerMatrix Composites Used for Strengthening of CivilStructures1This standard is issued under the fixed designation D7565/D7565M; the number immediately following the designation indicates theye
2、ar of original adoption or, 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 describes the requirements for sampl
3、epreparation, tensile testing, and results calculation of flat fiberreinforced polymer (FRP) composite materials used for thestrengthening of structures made of materials such as metals,timber, masonry, and reinforced concrete. The method may beused to determine the tensile properties of wet lay-up
4、andpre-impregnated FRP composites fabricated on site or manu-factured in a factory setting. The FRP composite may be ofeither unidirectional (0-degrees) or cross-ply (0/90 type) rein-forcement. For cross-ply laminates, the construction may beachieved using multiple-layers of unidirectional fibers at
5、 either0 or 90 degrees, or one or more layers of stitched or woven0/90 fabrics. The composite material forms are limited tocontinuous fiber or discontinuous fiber-reinforced compositesin which the laminate is balanced and symmetric with respectto the test direction. The method only covers the determ
6、inationof the tensile properties of the FRP composite material. Othercomponents used to attach the FRP material to the substrate,such as the primer, putty, and adhesive in externally bondedstrengthening systems, are excluded from the sample prepara-tion and testing detailed in this document. This te
7、st methodrefers to Test Method D3039/D3039M for conduct of the tests.1.2 The values stated in either SI units or inch-pound unitsare to be regarded as standard. Within the text, the inch-poundunits are shown in brackets. The values stated in each systemare not exact equivalents; therefore, each syst
8、em must be usedindependently of the other. Combining values from the twosystems may result in nonconformance with 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 a
9、ppro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD3039/D3039M Test Method for Tensile Properties ofPolymer Matrix Composite MaterialsD3878 Terminology for Co
10、mposite MaterialsD5229/D5229M Test Method for Moisture AbsorptionProperties and Equilibrium Conditioning of Polymer Ma-trix Composite MaterialsD5687/D5687M Guide for Preparation of Flat CompositePanels with Processing Guidelines for Specimen Prepara-tionE6 Terminology Relating to Methods of Mechanic
11、al TestingE122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and Statistics3. Terminology3.1 DefinitionsTermin
12、ology D3878 defines terms relatingto high-modulus fibers and their composites. TerminologyD883 defines terms relating to plastics.Terminology E6 definesterms relating to mechanical testing. Terminology E456 andE177 define terms relating to statistics. In the event of aconflict between terms, Termino
13、logy D3878 shall have prece-dence over the other standards.3.2 Definitions of Terms Specific to This Standard:3.2.1 screed, vto move a flat rule along the top of asaturated laminate to level the top of the laminate andsimultaneously remove excess resin.3.2.2 shop-manufactured FRP composite, nan FRP
14、com-posite material manufactured under controlled conditions usingan automated process in a factory, typically with tight controlover the volume fractions and alignment of fibers, matrix, and1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct res
15、ponsibility of Subcommittee D30.05 onStructural Test Methods.Current edition approved April 1, 2010. Published May 2010. Originallyapproved in 2009. Last previous edition approved in 2009 as D7565/D7565M 09.DOI: 10.1520/D7565_D7565M-10.2For referenced ASTM standards, visit the ASTM website, www.astm
16、.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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.voids in t
17、he material as well as the cross-sectional geometry.For strengthening applications, shop-manufactured FRP com-posites are typically bonded to the substrate subsequent to thefabrication of the composite reinforcement3.2.3 wet lay-up FRP composite, nan FRP compositematerial fabricated by manually impr
18、egnating dry fibers with amatrix of polymeric resin. Semi-automated processes such asmachine-aided wetting of fabrics before placement or vacuum-aided impregnation of laminates after placement are consideredpart of wet lay-up FRP. For civil infrastructure strengtheningapplications, the degree of con
19、trol over the volume fractions offibers, matrix, and voids as well as the overall cross-sectionalgeometry in wet lay-up FRP composites may be less than thatfor shop-manufactured composites on account of the manualprocess. For strengthening applications, wet lay-up FRP com-posites are typically appli
20、ed to the substrate at the same timethe dry fiber is impregnated. The impregnating resin acts as thesaturant for the FRP composite and as the bonding agentbetween the composite reinforcement and the substrate. Wetlay-up specimens may be fabricated in either a field or alaboratory setting.3.3 Symbols
21、:3.3.1 CVsample coefficient of variation.3.3.2 F*force carrying capacity of FRP laminate per unitwidth.3.3.3 K*stiffness of FRP laminate per unit width.3.3.4 Lgextensometer gage length.3.3.5 nnumber of specimens.3.3.6 Pforce carried by test coupon.3.3.7 Pmaxmaximum tensile force.3.3.8 sn1sample stan
22、dard deviation.3.3.9 wcoupon width.3.3.10 xItest result for an individual coupon from thesample population for a given property.3.3.11 xmean or average (estimate of mean) of a samplepopulation for a given property.3.3.12 snormal stress.4. Summary of Test Method4.1 Flat FRP specimens are prepared usi
23、ng a wet lay-upfabrication procedure or cut from a shop-manufactured lami-nate. For testing purposes, wet lay-up material may be preparedin a laboratory or field setting, as the testing objectives dictate.The testing of the specimens is carried out according to theprovisions of Test Method D3039/D30
24、39M. The ultimate forceper unit width of the material is determined from the maximumforce carried before failure. If the load-strain response of thematerial is monitored with strain gages or extensometers, thenthe stiffness of the material per unit width and the ultimatetensile strain of the materia
25、l may be determined.5. Significance and Use5.1 This test method can be used to obtain the tensile forcecapacity and ultimate tensile strain of FRPmaterial used for thestrengthening of other structural materials such as, metals,timber, and reinforced concrete. The principal test variablescould be the
26、 FRP constituents and fabrication method or thesize or type of FRP laminate. The obtained tensile propertiescan be used for material specifications, quality control andassurance, structural design and analysis, and research anddevelopment.5.2 This test method focuses on the FRP material itself,irres
27、pective of the gripping method.Therefore, maximum forceand strain data associated with failure or pullout at either gripare disregarded. The force capacity and maximum strainmeasurements are based solely on test specimens that fail in thegauge section.6. Interferences6.1 A summary of the interferenc
28、es, specifically materialand specimen preparation, gripping, system alignment, andedge effects are presented in D3039/D3039M.6.2 Additional interferences may arise from lack of controlin wet lay-up specimen preparation procedures outlined in8.3.1. Specimen variations in resin content, ply thickness,
29、 voidcontent and degree of cure may contribute to variability in testresults.7. Apparatus7.1 Requirements for testing machines and instrumentationare the same as those given in D3039/D3039M, Section 7.8. Sampling and Test Specimens8.1 SamplingTest at least five specimens per test condi-tion unless v
30、alid results can be gained through the use of fewerspecimens, such as in the case of a designed experiment. Forstatistically significant data, the procedures outlined in PracticeE122 should be consulted. Report the method of sampling.NOTE 1If specimens are to undergo environmental conditioning toequ
31、ilibrium, and are of such type or geometry that the weight change ofthe material cannot be properly measured by weighing the specimen itself(such as a tabbed mechanical coupon), then use another traveler coupon ofthe size (but without tabs) to determine when equilibrium has beenreached for the speci
32、mens being conditioned.8.2 GeometryVariation in specimen width should be nogreater than 61%. Specimens width should be determined perTest Method D3039/D3039M, Section 7.1. Other dimensionsshall conform to Test Method D3039/D3039M Section 8.2.1with the exception of thickness, which is not required to
33、 bemeasured. Specimen thickness may however be measured aspart of the general characterization of the specimen, and shouldbe reported if measured.NOTE 2Calculations according to this method are based on force perunit coupon width and stiffness per unit coupon width. Specimenthickness is not required
34、 for these calculations.8.2.1 Specimen WidthMinimum specimen width for uni-directional shop-manufactured and wet lay-up FRP specimensshall be 25 mm 1.0 in. Minimum width for cross-plyspecimens shall be 25 mm 1.0 in. for shop-manufacturedcomposites and 38 mm 1.5 in. for wet lay-up composites.NOTE 3Fo
35、r both unidirectional and cross-ply laminates, where fibersare used in large bundles (i.e, rovings, tows) that will be wider than 3 mm0.12 in. when laid into the laminate, it is recommended that a specimenwidth of 38 mm 1.5 in. or higher be used.8.3 Specimen Preparation:D7565/D7565M 1028.3.1 Wet Lay
36、-up FRPA polymer release film, typically600 x 600 mm 24 x 24 in. is placed on a smooth, flathorizontal surface. The release film should be at least 0.076mm 0.003 in. thick and made of a polymer that will notadhere to the resin used to impregnate the fibers. Usually,acetate and nylon are acceptable.
37、Resin is first applied to therelease film. The first ply of dry fiber preform with a minimumdimension of 300 x 300 mm 12 x 12 in. is saturated or coatedwith the specified amount of resin and placed on the releasefilm. This can be done using a properly calibrated saturatormachine or using a manufactu
38、rer-specified fiber to resin weightratio. The specified number of plies at the specified angles (0 or90 degrees) are sequentially impregnated with resin andstacked onto the release film using the specified amount ofresin per ply per unit area as in the actual installation. Using theflat edge of a sm
39、all hand tool or a grooved roller, air bubblesare worked out of the material. The bubbles should be workedout in the direction of the primary fibers to ensure that nodamage is caused to the fibers. A second release film is thenplaced over the material to provide protection. An alternativemethod to e
40、liminate air bubbles is to use the flat edge of a smallpaddle on the outer side of the upper release film to force theentrapped air out of the material with a screeding action in theprimary fiber direction. In order to ensure a smooth top surfaceof the FRP material, a rigid flat plate should be plac
41、ed on topof the top layer of release film while the resin cures. Thelaminate should be placed in an area of the jobsite so as to notinterfere with the installation and allowed to cure according tothe manufacturers recommendation. After the specified curingprocedure is complete, the release films are
42、 removed from thepanel. Specimens may be cut and tabbed after the curingprocedure.NOTE 4The final fiber, resin, and void content of the material willdepend on the method of rolling or screeding the material duringfabrication. If the aim of testing is to evaluate FRP material representativeof the ins
43、talled strengthening material, rolling and screeding proceduresused to prepare specimens should resemble those used for the installedstrengthening material.NOTE 5Guide D5687/D5687M provides guidelines for strictly con-trolling the preparation of composite test specimens in the laboratory.Preparation
44、 of wet lay-up FRPshould follow these guidelines to the extentthat they are compatible with the intended cure and laminate consolidationregimes specified for the wet-laid FRP composite system. The lay-up andlaminate consolidation steps presented in Guide D5687/D5687M are ofparticular relevance to th
45、is standard.8.3.2 Shop-Manufactured FRPThe thickness of shop-manufactured FRP is predetermined and should not be altered.Specimen width may be altered by the agreement of therequestor and material manufacturer. Care should be taken toensure that the specimen is flat. Testing of non-flat specimensmay
46、 result in lower tensile strength due to induced moments.8.3.3 Machining MethodsSpecimen preparation is ex-tremely important for this test method. If specimens are cutfrom plates, take precautions to avoid notches, undercuts,rough or uneven surfaces, or delaminations caused by inappro-priate machini
47、ng methods. Obtain final dimensions by water-lubricated precision sawing, milling, or grinding. The use ofdiamond tooling has been found to be extremely effective formany material systems. Edges should be flat and parallelwithin the tolerances specified in 8.2. See Appendix X3 ofGuide D5687/D5687M f
48、or specific recommendations on speci-men machining methods.8.3.4 LabelingLabel the specimens so that they will bedistinct from each other and traceable back to the raw material.Labeling must be unaffected by the test and must not affect theoutcome of the test.9. Calibration9.1 The accuracy of all me
49、asuring equipment shall havecertified calibrations that are current at the time of use 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 resu
