1、Designation:D7914/D7914M14Standard Test Method forStrength of Fiber Reinforced Polymer(FRP)Bent Bars inBend Locations1This standard is issued under the fixed designation D7914/D7914M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,th
2、e 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 determines the quasi-static ultimatestrength of fiber reinforced polymer(FRP)composite bent bars
3、commonly used as anchorages for stirrups in reinforced,prestressed,or post-tensioned concrete structures.This testmethod only applies to bars with a solid cross section.1.2 FRP bent bars are often used in reinforced concreteapplications to shorten the development length of the bar or toact as a tie
4、or a stirrup to resist shear forces.Bent bars can beproduced with varying angles of bend in order to fit theirintended purpose.1.3 For this test method,the FRP bars are bent at a 90degree angle.In general,bars have a regular pattern of surfaceundulations,a coating of bonded particles,or both,thatpro
5、mote mechanical interlock between the bar and concrete.1.4 The strength values provided by this method are short-term,quasi-static tensile strengths that do not account forsustained static or cyclic loading.If bars are to be used underhigh levels of sustained or repeated loading,additional materialc
6、haracterization may be required.1.5 The characteristic values obtained from this test methodare intended to represent the quasi-static ultimate strength ofFRP bent bars with a tail length of twelve bar diameters.1.6 The values stated in either SI units or inch-pound unitsare to be regarded separatel
7、y 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 standard.1.6.1 Within the text,the inch-pound units are shown inbrackets.1.7 This standa
8、rd 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 use.2.Referenced Documents2.1 ASTM St
9、andards:2A615/A615M Specification for Deformed and Plain Carbon-Steel Bars for Concrete ReinforcementC39/C39M Test Method for Compressive Strength of Cylin-drical Concrete SpecimensC143/C143M Test Method for Slump of Hydraulic-CementConcreteC192/C192M Practice for Making and Curing Concrete TestSpec
10、imens in the LaboratoryD792 Test Methods for Density and Specific Gravity(Rela-tive Density)of Plastics by DisplacementD883 Terminology Relating to PlasticsD3171 Test Methods for Constituent Content of CompositeMaterialsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAb
11、sorption 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 Terminology Relating to Methods of Mechanical TestingE122 Pr
12、actice 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-modulus fibers and their composites.Terminology in D883def
13、ines terms relating to plastics.Terminology in E6 definesterms relating to mechanical testing.Terminology in E456 andin Practice E122 define terms relating to statistics and theselection of sample sizes.In the event of a conflict between1This test method is under the jurisdiction of ASTM Committee D
14、30 onComposite Materials and is the direct responsibility of Subcommittee D30.10 onComposites for Civil Structures.Current edition approved Aug.1,2014.Published December 2014.DOI:10.1520/D7914_D7914M-14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Servic
15、e at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 terms,Terminology in D3878 shall have precedence over
16、 theother terminology standards.3.2 Definitions: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 bend radius,ninside radius of the bend.3.2.3 bend strength,nultimate tensile stress that can becarried by the FRP bent bar provided that failure occurs in thebend.3.2.4 bent bar,na bar with a section formed in such amanner as to deviate from its primary axis.3.2.5 equivalen