1、Designation: D7957/D7957M 17Standard Specification forSolid Round Glass Fiber Reinforced Polymer Bars forConcrete Reinforcement1This standard is issued under the fixed designation D7957/D7957M; 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 specification covers glass fiber reinforced polymer(GFRP) bars, provided in cut lengths an
3、d bent shapes andhaving an external surface enhancement for concrete reinforce-ment. Bars covered by this specification shall meet the require-ments for geometric, material, mechanical, and physical prop-erties described herein.1.2 Bars produced according to this standard are qualifiedusing the test
4、 methods and must meet the requirements givenby Table 1. Quality control and certification of production lotsof bars are completed using the test methods and must meet therequirements given in Table 2.1.3 The text of this specification references notes andfootnotes which provide explanatory material
5、. These notes andfootnotes (excluding those in tables) shall not be considered asrequirements of the specification.1.4 The following FRP materials are not covered by thisspecification:1.4.1 Bars made of more than one load-bearing fiber type(that is, hybrid FRP).1.4.2 Bars having no external surface
6、enhancement (that is,plain or smooth bars, or dowels).1.4.3 Bars with geometries other than solid, round crosssections.1.4.4 Pre-manufactured grids and gratings made with FRPmaterials.1.5 This specification is applicable for either SI (as Speci-fication D7957M) or inch-pound units (as SpecificationD
7、7957).1.6 The values stated in either inch-pound units or SI 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 system shall be usedindependently of the other. Combining values fr
8、om the twosystems may result in nonconformance with the specification.1.7 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, health and environmental practices an
9、d deter-mine the applicability of regulatory limitations prior to use.1.8 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 Recom-
10、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 ReinforcementC904 Terminology Relating to Chemical-Resistant Nonme-tallic MaterialsD5
11、70 Test Method for Water Absorption of PlasticsD792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD2584 Test Method for Ignition Loss of Cured ReinforcedResinsD3171 Test Methods for Constituent Content of CompositeMaterialsD3878 Terminology for Composit
12、e MaterialsD7205/D7205M Test Method for Tensile Properties of FiberReinforced Polymer Matrix Composite BarsD7617/D7617M Test Method for Transverse Shear Strengthof Fiber-reinforced Polymer Matrix Composite BarsD7705/D7705M Test Method for Alkali Resistance of FiberReinforced Polymer (FRP) Matrix Com
13、posite Bars usedin Concrete ConstructionD7913/D7913M Test Method for Bond Strength of Fiber-Reinforced Polymer Matrix Composite Bars to Concreteby Pullout TestingD7914/D7914M Test Method for Strength of Fiber Rein-forced Polymer (FRP) Bent Bars in Bend Locations1This specification is under the juris
14、diction 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 August 2017. Originallyapproved in 2017. DOI: 10.1520/D7957_D7957M-17.2For referenced ASTM standards, visit t
15、he 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 onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.
16、United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barr
17、iers to Trade (TBT) Committee.1E1356 Test Method for Assignment of the Glass TransitionTemperatures by Differential Scanning CalorimetryE2160 Test Method for Heat of Reaction of ThermallyReactive Materials by Differential Scanning Calorimetry3. Terminology3.1 Definitions:3.1.1 Terminology C904 defin
18、es terms relating to chemical-resistant nonmetallic materials. Terminology D3878 definesterms relating to high-modulus fibers and their composites.3.2 Definitions of Terms Specific to This Standard:3.2.1 bar, na straight or bent element with a solid, roundcross section in the straight portion, havin
19、g surface enhance-ment that intends to provide mechanical interlock with con-crete.3.2.2 bend angle, nthe intentional deviation of a portionof a bar from the main axis of the bar, measured in degrees.3.2.3 bend diameter, nthe inside diameter of a bent bar, asprovided in Table 4.3.2.4 commercial grad
20、e material, na material formulatedfor and used in industrial (not consumer) applications.3.2.5 guaranteed property, na characteristic value pro-vided by the manufacturer less than or equal to the mean minusthree standard deviations of the samples tested according to aspecified method.3.2.6 mean prop
21、erty, na value provided by the manufac-turer less than or equal to the mean of the samples testedaccording to a specified method.TABLE 1 Property Limits and Test Methods for QualificationAProperty Limit Test MethodMean Glass Transition Temperature Midpoint temperature $100 C 212 F ASTM E1356Mean Deg
22、ree of Cure $95 % ASTM E2160Mean Measured Cross-Sectional Area Table 3 ASTM D7205/D7205M, subsection 11.2.5.1GuaranteedBUltimate Tensile Force Table 3 ASTM D7205/D7205MMean Tensile Modulus of Elasticity $44,800 MPa 6 500 000 psi ASTM D7205/D7205MMean Ultimate Tensile Strain $1.1 % ASTM D7205/D7205MG
23、uaranteedBTransverse Shear Strength $131 MPa 19 000 psi ASTM D7617/D7617MGuaranteedBBond Strength $7.6 MPa 1100 psi ASTM D7913/D7913MMean Moisture Absorption to Saturation #1.0 % to saturation at 50 C 122 F ASTM D570, subsection 7.4Mean Alkaline Resistance$80 % of initial mean ultimate tensile force
24、 following90 days at 60 C 140 FASTM D7705/D7705M, Procedure AGuaranteedBUltimate Tensile Force of Bent Portionof Bar$60 % of the values in Table 3 ASTM D7914/D7914MAFor the determination of the mean and guaranteed properties, at least 24 samples shall be obtained in groups of eight or more from thre
25、e or more different productionlots. The mean and guaranteed properties shall satisfy the limits.BGuaranteed property is defined in 3.2.5.TABLE 2 Property Limits and Test Methods for Quality Control and CertificationA,BProperty Limit Test MethodFiber Mass Content $70 % ASTM D2584 or ASTM D3171Glass T
26、ransition Temperature Midpoint temperature $100 C 212 F ASTM E1356Degree of Cure $95 % ASTM E2160Measured Cross-Sectional Area Table 3 ASTM D7205/D7205M, subsection 11.2.5.1Ultimate Tensile Force Table 3 ASTM D7205/D7205MTensile Modulus of Elasticity $44 800 MPa 6 500 000 psi ASTM D7205/D7205MUltima
27、te Tensile Strain $1.1 % ASTM D7205/D7205MMoisture Absorption in 24 h #0.25 % in 24 h at 50 C 122 F ASTM D570, subsection 7.4AFor the determination of each of the property limits, five random samples shall be obtained from each production lot. Each individual sample shall satisfy the propertylimits.
28、BFor bent bars, the tests are performed on the straight portion of the bars.TABLE 3 Geometric and Mechanical Property RequirementsBarDesignationNo.Nominal DimensionsMeasured Cross-Sectional Area Limitsmm2in.2MinimumGuaranteedUltimateTensile ForcekN kipDiametermm in.Cross-Sectional Areamm2in.2Minimum
29、 MaximumM6 2 6.3 0.250 32 0.049 30 0.046 55 0.085 27 6.1M10 3 9.5 0.375 71 0.11 67 0.104 104 0.161 59 13.2M13 4 12.7 0.500 129 0.20 119 0.185 169 0.263 96 21.6M16 5 15.9 0.625 199 0.31 186 0.288 251 0.388 130 29.1M19 6 19.1 0.750 284 0.44 268 0.415 347 0.539 182 40.9M22 7 22.2 0.875 387 0.60 365 0.5
30、65 460 0.713 241 54.1M25 8 25.4 1.000 510 0.79 476 0.738 589 0.913 297 66.8M29 9 28.7 1.128 645 1.00 603 0.934 733 1.137 365 82.0M32 10 32.3 1.270 819 1.27 744 1.154 894 1.385 437 98.2D7957/D7957M 1723.2.7 measured cross-sectional area, nthe average cross-sectional area of a representative bar, incl
31、uding deformations,lugs, sand coating or any bond-enhancing surface treatment,measured according to Test Method D7205/D7205M.3.2.8 nominal bar diameter, na standard diameter of a bar,as described in Table 3.3.2.9 nominal cross-sectional area, na standard cross-sectional area of a bar, as described i
32、n Table 3.3.2.10 production lot, ndetermined by the manufacturer,as any batch of bar produced from start to finish with the sameconstituent materials used in the same proportions withoutchanging any production parameter, such as cure temperatureor line speed.3.2.11 size designation, nan alphanumeric
33、 identifier cor-responding to the bar designation number of Table 3.3.2.12 surface enhancement, nprotrusions, lugs, sandcoatings, deformations or any additional surface treatment thatprovides means of mechanically transmitting force between thebar and the concrete surrounding the bar in such constru
34、ction.3.2.13 test, certification, nan optional test, specified bythe purchaser, to certify that the material provided for a givenproject meets the requirements of the specification.3.2.14 test, qualification, na test completed under thesupervision of the manufacturer to ensure conformance ofmaterial
35、 to the requirements of a specification.3.2.15 test, quality control, na test completed on eachproduction lot of material, under the supervision of themanufacturer, to ensure that the process of manufacturing theproduct remains under control.4. Ordering Information4.1 It shall be the responsibility
36、of the purchaser to specifyall requirements that are necessary for material ordered to thisspecification. Such requirements shall include:4.1.1 Name of the FRP material (manufacturersdescription),4.1.2 Quantity of each individual bar length,4.1.3 Bar designation number (size),4.1.4 Cut length, and4.
37、1.5 For bent bars, the shape of the bend, the diameter ofthe bend, and the length of the legs.4.1.6 Production lot certification report, if desired.NOTE 1Descriptive bar list part numbering can be helpful in commu-nicating the designers intent to the fabricator, supplier, placement of thereinforcing
38、, procurement, and job site inspection. An example of descrip-tive part numbering for GFRP bars is shown in Appendix X1.5. Constituent Materials and Manufacture5.1 Reinforcing FibersGlass fibers shall be in the form ofcontinuous unidirectional rovings.5.2 Matrix Resins:5.2.1 Vinyl ester thermoset re
39、sin systems are permitted,provided the finished product meets the physical and durabilityrequirements of this specification.5.2.2 The base polymer in the resin system should notcontain any polyester.5.3 Manufacturing Process:5.3.1 Process or material modifications are not permittedduring the product
40、ion of a single production lot.5.3.2 The manufacturer shall document the process usedand report the date(s) of production and quantity of materialproduced in the production lot.5.3.3 The manufacturer shall maintain a documented qualitycontrol plan that details the activities of the processmonitoring
41、, production inspection, and record keeping. Theplan shall be made available to customers upon request.5.3.3.1 The manufacturer shall use all tests in Table 2 as partof the quality control process. A record of these quality controltests shall be kept for each lot of material and shall be madeavailab
42、le to the purchaser upon request. The manufacturer mayuse other tests as part of internal quality control processes.Results from such tests are not required to be reported.6. Physical Properties6.1 Fiber Mass ContentThe fiber mass content shall bedetermined by Test Method D2584 or Test Methods D3171
43、,ata frequency and number of specimens as indicated in Section10. The fiber mass content is calculated as the mass of thelongitudinal fibers divided by the mass of the longitudinalfibers plus resin. Excluded from this calculation are thematerials added to the bar for bond enhancement. The fibermass
44、content shall be in accordance with the limit given inTable 2.6.2 Glass Transition TemperatureThe glass transitiontemperature shall be determined using specimens cut from theas-produced bar, by Test Method E1356, at a frequency andnumber of specimens as indicated in Section 10. Test results forthe f
45、irst temperature scan shall be used to determine the glasstransition temperature. The glass transition temperature shallbe in accordance with the limits given in Tables 1 and 2.6.3 Degree of CureThe degree of cure shall be determinedusing specimens cut from the as-produced bar, by Test MethodE2160,
46、at a frequency and number of specimens as indicated inSection 10. The degree of cure shall be in accordance with thelimits given in Tables 1 and 2.6.4 Bar Sizes:6.4.1 Bar size and measured cross-sectional area, as de-scribed below, are established on straight sections of bar.6.4.2 The size designati
47、on of bars meeting this specificationshall be in bar number designations or metric equivalentsconsistent with the practice for steel bars as described inSpecification A615/A615M.TABLE 4 Minimum Inside Bend Diameter of Bent BarsABar Designation,mm U.S. StandardMinimum BendDiameter mm in.M6 2 38 1.50M
48、10 3 58 2.25M13 4 76 3.00M16 5 96 3.75M19 6 114 4.50M22 7 134 5.25M25 8 152 6.00ABent bars of designation M29 9 and M32 10 are not included in thisspecification.D7957/D7957M 1736.4.3 Mechanical properties reported in this specificationare established based on the nominal cross-sectional area asprovi
49、ded in Table 1.6.4.4 The measured cross-sectional area of the bar shall bedetermined by Test Method D7205/D7205M, subsection11.2.5.1, based on the method given in Test Methods D792,and shall be measured on the as-manufactured bar, includingsurface enhancements, at a frequency and number of speci-mens as indicated in Section 10. The measured cross-sectionalarea shall be within the mini
