1、Designation: A820/A820M 11Standard Specification forSteel Fibers for Fiber-Reinforced Concrete1This standard is issued under the fixed designation A820/A820M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revisio
2、n. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers minimum requirements forsteel fibers intended for use in fiber-reinforced concrete. Fivetypes of steel
3、fibers for this purpose are defined as pieces ofsmooth or deformed cold-drawn wire; smooth or deformed cutsheet; melt-extracted fibers; mill-cut or modified cold-drawnwire steel fibers that are sufficiently small to be dispersed atrandom in a concrete mixture.1.2 This specification provides for meas
4、urement of dimen-sions, tolerances from specified dimensions, and requiredminimum physical properties, and prescribes testing proce-dures to establish conformance to these requirements.1.3 In the case of conflict between a requirement of aproduct specification and a requirement of this specification
5、,the product specification shall prevail. In the case of a conflictbetween a requirement of the product specification or arequirement of this specification and a more stringent require-ment of the purchase order, the purchase order shall prevail.The purchase order requirements shall not take precede
6、nce ifthey, in any way, violate the requirements of the productspecification or this specification; for example, by the waivingof a test requirement or by making a test requirement lessstringent.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. Th
7、e 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.2. Referenced Documents2.1 The following documents, of the issue in effect on thedate of mat
8、erial purchase, form a part of this specification tothe extent referenced herein.2.2 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA700 Practices for Packaging, Marking, and Loading Meth-ods for Steel Products for ShipmentC1116/C1116M Specification for Fibe
9、r-Reinforced Con-crete2.3 ACI Documents:3ACI 506.1 Guide to Fiber-Reinforced ShotcreteACI 544.1R Committee Report on Fiber-Reinforced Con-crete2.4 U.S. Federal Standards:4Fed. Std. No. 123 Marking for Shipment (Civil Agencies)2.5 U.S. Military Standards:4MIL-STD-129 Marking for Shipment and Storage3
10、. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 deformed fiber, na fiber that is bent, flattened, orroughened to improve mechanical bond to the concrete matrix.3.1.2 modified fiber, na cold-drawn wire fiber whosecross-section has been changed from circular by shaving thewire.3.
11、1.3 nominal length, nthe length of a deformed fiber,out-to-out, after being deformed.3.1.4 range of equivalent diameter, de-r, na set of limitsplaced on the equivalent diameter by the specifier. See 8.1.6and Note 3.3.2 SymbolsThe following symbols used in this specifi-cation are defined as follows:A
12、 = cross-sectional area, in.2mm2d = diameter, in. mmfu= ultimate tensile strength, psi MPal = length, in. mml = l/d = aspect ratio1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.05 on
13、Steel Reinforcement.Current edition approved Oct. 1, 2011. Published October 2011. Originallyapproved in 1985. Last previous edition approved in 2006 as A820/A820M 06.DOI: 10.1520/A0820_A0820M-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
14、 serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Concrete Institute (ACI), P.O. Box 9094, FarmingtonHills, MI 48333-9094, http:/www.concrete.org.4Available from Standardization Documents Or
15、der Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.1 The
16、 subscript n on dimensional units indicates “nomi-nal” and the subscript e indicates “equivalent.” “Nominal” and“equivalent” dimensions are calculated from other measurabledimensions or average weight mass.4. Classification4.1 Five general types of steel fibers are identified in thisspecification ba
17、sed upon the product or process used as asource of the steel fiber material.4.1.1 Type I, cold-drawn wire.4.1.2 Type II, cut sheet.4.1.3 Type III, melt-extracted.4.1.4 Type IV, mill cut.4.1.5 Type V, modified cold-drawn wire.4.2 Fibers shall be straight or deformed.5. Ordering Information5.1 It shal
18、l be the responsibility of the purchaser to specifyall requirements that are necessary for the product under thisspecification. Such requirements to be considered include, butare not limited to, the following:5.1.1 ASTM designation and year of issue,5.1.2 Quantity in pounds or tons kilograms,5.1.3 T
19、ype or types permissible (4.1),5.1.4 Diameter or equivalent diameter (8.1.4), or range ofequivalent diameters (8.1.6),5.1.5 Length or nominal length (3.1.3),5.1.6 Deformations, if required, and5.1.7 Whether certification by the manufacturer is requiredincluding whether a report is to be furnished (S
20、ection 11).NOTE 1For information on satisfactory sizes and aspect ratios, seeACI 544.1R and ACI 506.1, and contact the manufacturers regardingavailability.6. Materials and Manufacture6.1 The materials and manufacturing methods used shall besuch that the fibers produced conform to the requirements in
21、this specification.7. Mechanical Properties7.1 Tensile Requirements:7.1.1 At least ten individual tensile tests of randomlyselected finished fibers shall be performed for each 5 tons4 500 kg of product. This is an approximate distribution ofone fiber tensile test per every 0.5 ton 450 kg of finished
22、product. The average tensile strength, fu, of each fiber shall notbe less than 50 000 psi 345 MPa. The tensile strength of anyone of the ten specimens shall not be less than 45 000 psi310 MPa. Where the parent source material consists of sheetor wire, tensile tests by the manufacturer may be perform
23、ed onlarger samples of source material. One sample of each differentsource material used shall then be tested for each 5 tons4 500 kg of material. The tensile strength of a single sampleof source material shall not be less than 50 000 psi 345 MPa.7.1.2 The cross-sectional area used to compute fushal
24、l becarried out to five decimal places, in units of square inchessquare millimetres, and shall be: (1) for drawn wire fibers,Type I, the area calculated from the actual diameter of theparent source material or finished fiber; (2) for cut sheet fibers,Type II, the area calculated from the actual thic
25、kness and widthof the parent source material specimen, or if fibers are tested,the area of each individual fiber calculated from measuredlength and weight mass of the fiber. See 8.1.5. (3) formelt-extracted fibers, Type III, or mill-cut fibers, Type IV,specified by equivalent diameter, the area calc
26、ulated from theequivalent diameter of the fibers. See 8.1.5; and (4) formodified cold drawn wire fibers, Type V, specified by a range ofequivalent diameters, the area of each individual fiber calcu-lated from the measured length and weight mass of the fiber.See 8.1.6. The ultimate tensile load in po
27、unds-force newtonsfor individual fibers shall be measured to at least threesignificant figures. Testing shall be in accordance with TestMethods and Definitions A370, where applicable.7.2 Bending Requirements:7.2.1 Fibers shall withstand being bent around a 0.125 in.3.2 mm diameter pin to an angle of
28、 90 at temperatures notless than 60F 16C without breaking.NOTE 2The bending requirements of this specification provide ageneral indication of fiber ductility, as may be important in resistingbreakage during handling and mixing operations. Ductility measures offiber-reinforced concrete are outside th
29、e scope of this specification; seeACI 544.1R.7.2.2 Bend tests shall be conducted on ten randomly se-lected specimens of finished fibers. It shall be permissible toperform bend tests manually. At least one test consisting of tenspecimens shall be made for each 5 tons 4 500 kg of material.At least 90
30、% of the specimens must pass the test.8. Dimensions and Permissible Variations8.1 Dimensions:8.1.1 Straight cold-drawn wire (Type I) fibers are specifiedby diameter (d) or equivalent (de) and length (l), that establisha specified aspect ratio, (l), or (le), as (l / d)or(l / de).8.1.2 Deformed cold-d
31、rawn wire (Type I) fibers are speci-fied by the diameter (d) or equivalent diameter (de) andnominal length after bending (ln). Nominal aspect ratio (ln)isestablished as (ln/ d)or(ln/ de).8.1.3 Cut sheet (Type II) fibers are specified by thickness (t),width (w), and length (l). Aspect ratio (l) can b
32、e computed as:l5l / dewhere:A = tw, andde= equivalent diameter =4A / p .8.1.4 Deformed cut sheet (Type II) fibers are specified bythickness (t), width (w), and nominal length after deformation(ln). Nominal aspect ratio (ln) can be computed as follows.l5ln/ dewhere:A = tw, andde= equivalent diameter
33、=4A / p .8.1.5 Melt-extracted (Type III) and mill-cut (Type IV) fibersare specified by equivalent diameter, (de), and length (l), ornominal length (ln). Equivalent diameter is computed frommeasured average nominal length and the weight mass of aknown quantity of fibers, based upon 0.284 lb/in.37 865
34、 kg/A820/A820M 112m3 measured to the nearest 2 3 10-6lb 0.1 mg. Nominalaspect ratio, (ln), can be computed as follows:ln5 l / de, or 5 ln/ de8.1.6 Modified cold-drawn wire fibers (Type V) are speci-fied by a range of equivalent diameters, (de-r), and length (l), ornominal length (ln). Equivalent dia
35、meter is computed as in8.1.5. A range of nominal aspect ratios, (ln-r) can be computedas follows:ln2r5 l / de2r, or 5 ln/ de2rNOTE 3Specifying a specific diameter or equivalent diameter forType V fibers is not applicable as the diameters of many Type V fibersvary more than 610 % in each lot. Therefo
36、re a user should provide thelimits on diameter or equivalent diameter allowable.8.2 Measurement of Dimensions:8.2.1 Measurement of dimensions shall be performed on notless than 10 randomly selected specimens for each test toestablish the average for conformance to specified tolerances.At least 90 %
37、of the specimens in each test shall meet thespecified tolerances for length, diameter or equivalent diam-eter, and aspect ratio.8.2.2 At least one test shall be performed for 5 tons4 500 kg of finished product.8.3 Permissible Variations:8.3.1 The length, or nominal length shall not vary from itsspec
38、ified value more than 610 %.8.3.2 The diameter, equivalent diameter, or range of equiva-lent diameters shall not vary from its specified value more than610 %.8.3.3 The aspect ratio, nominal aspect ratio, or range ofaspect ratios shall not vary from its specified value more than615 %.9. Workmanship,
39、Finish, and Appearance9.1 Surface Condition:9.1.1 Seams and surface irregularities shall not be cause forrejection provided that tensile properties are not less thanrequirements of this specification and mixing performance inconcrete is not adversely affected.9.1.2 Rust, mill scale, or other coating
40、s shall not be causefor rejection provided that the individual fibers separate whenmixed in concrete in accordance with Specification C1116/C1116M, and tensile and bending properties are not less thanthe requirements of this specification.10. Inspection10.1 Unless otherwise specified in the purchase
41、 order orcontract, the manufacturer is responsible for the performanceof all inspection and test requirements specified herein. Exceptas otherwise specified in the purchase order or contract, themanufacturer may use his own or any other suitable facility forthe performance of the inspection and test
42、 requirements speci-fied herein unless disapproved by the purchaser. The purchasershall have the right to perform any of the inspections and testsset forth in this specification where such inspections aredeemed necessary to ensure that material conforms to pre-scribed requirements.11. Rejection and
43、Rehearing11.1 Rejection:11.1.1 If any test fails to conform to the requirements of thisspecification, it shall be cause for rejection of the materialrepresented by the test. Material that is found to be defectivesubsequent to its acceptance at the manufacturers works maybe rejected, and the manufact
44、urer notified.11.1.2 Rejection of fibers shall be reported to the manufac-turer promptly and in writing. Samples representing fibersrejected by the purchaser shall be preserved until disposition ofthe claim has been agreed to between the supplier and thepurchaser.11.2 RehearingWhen any test fails to
45、 meet the require-ments of tension, bending, or dimensional tolerances, a retestshall be allowed. This retest shall be performed on twice thenumber of randomly selected specimens originally tested. Theresults of the retest shall meet the requirements of thisspecification or the lot shall be rejected
46、.12. Certification12.1 Certificate of ComplianceWhen specified in thepurchase order or contract, the producer or supplier shallfurnish a certificate of compliance stating the product wasmanufactured, sampled, tested, and inspected in accordancewith this specification (including year of issue) and an
47、y otherrequirements designated in the purchase order or contract, andhas been found to meet such requirements.12.2 Test ReportsWhen specified in the purchase order orcontract, test reports shall be furnished to the purchasercontaining the results of all tests required by this specification(including
48、 year of issue), and any other requirements desig-nated in the purchase order or contract.12.3 A signature or notarization is not required; however,the document shall clearly identify the organization submittingthe document. Notwithstanding the absence of a signature, theorganization submitting the
49、document is responsible for itscontent.12.4 Copies of the original manufacturers test report shallbe included with any subsequent test report. A certificate ofcompliance (or test report) printed from or used in electronicform from an electronic data interchange (EDI) shall beregarded as having the same validity as a counterpart printed inthe certifying organizations facility. The content of the EDI-transmitted document must conform to any existing EDIagreement between the purchaser and the supplier.13. Packaging and
