1、Designation: A 820/A 820M 06Standard Specification forSteel Fibers for Fiber-Reinforced Concrete1This standard is issued under the fixed designationA 820/A 820M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) 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 st
3、eel 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
4、measurement 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 specifica
5、tion,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 pre
6、cedence 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 the stan
7、dard. Within the text,the inch-pound units are shown in brackets. The values statedin each 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
8、.1 The following documents, of the issue in effect on thedate of material purchase, form a part of this specification tothe extent referenced herein.2.2 ASTM Standards:2A 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA 700 Practices for Packaging, Marking, and LoadingMethod
9、s for Steel Products for ShipmentC 1116 Specification for Fiber-Reinforced Concrete andShotcrete2.3 ACI Document:544.1R Committee Report on Fiber-Reinforced Concrete32.4 U.S. Military Standard:MIL-STD-129 Marking for Shipment and Storage42.5 U.S. Federal Standard:Fed. Std. No. 123 Marking for Shipme
10、nt (Civil Agencies)43. 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
11、by shaving thewire.3.1.3 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
12、 defined as follows:A = cross-sectional area, mm2in.2d = diameter, mm in.fu= ultimate tensile strength, MPa psil = length, mm in.l = l/d = aspect ratio3.2.1 The subscript n on dimensional units indicates “nomi-nal” and the subscript e indicates “equivalent.” “Nominal” and1This specification is under
13、 the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel, and Related Alloys and is the direct responsibility of SubcommitteeA01.05 on Steel Reinforcement.Current edition approved March 1, 2006. Published March 2006. Originallyapproved in 1985. Last previous edition approved in 2004 as A 820
14、 04.2For referenced ASTM standards, visit the 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.3Available from American Concrete Institute, 38800 Countr
15、y Club Drive,Farmington Hills, MI 48331.4Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. Or visit: http:/assist.daps.dla.mil/online.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM Int
16、ernational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.“equivalent” dimensions are calculated from other measurabledimensions or average mass weight.4. Classification4.1 Five general types of steel fibers are identified in thisspecification based upon the pro
17、duct 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 shall be the respons
18、ibility 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 kg pounds or tons,5.1.3 Type or types permissibl
19、e (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 (Section 11).NOTE 1For in
20、formation on satisfactory sizes and aspect ratios, seeACI 544.1R, and contact the manufacturers regarding availability.6. Materials and Manufacture6.1 The materials and manufacturing methods used shall besuch that the fibers produced conform to the requirements inthis specification.7. Mechanical Pro
21、perties7.1 Tensile Requirements:7.1.1 At least ten individual tensile tests of randomlyselected finished fibers shall be performed for each 4 500 kg 5tons of product. This is an approximate distribution of onefiber tensile test per every 450 kg 0.5 ton of finished product.The average tensile strengt
22、h, fu, of each fiber shall not be lessthan 345 MPa 50 000 psi. The tensile strength of any one ofthe ten specimens shall not be less than 310 MPa 45 000 psi.Where the parent source material consists of sheet or wire,tensile tests by the manufacturer may be performed on largersamples of source materi
23、al. One sample of each differentsource material used shall then be tested for each 4 500 kg 5tons of material. The tensile strength of a single sample ofsource material shall not be less than 345 MPa 50 000 psi.7.1.2 The cross-sectional area used to compute fushall becarried out to five decimal plac
24、es, in units of square millimetressquare inches, and shall be: (1) for drawn wire fibers, Type I,the area calculated from the actual diameter of the parentsource material or finished fiber; (2) for cut sheet fibers, TypeII, the area calculated from the actual thickness and width ofthe parent source
25、material specimen, or if fibers are tested, thearea of each individual fiber calculated from measured lengthand mass weight of the fiber. See 8.1.5. (3) for melt-extractedfibers, Type III, or mill-cut fibers, Type IV, specified byequivalent diameter, the area calculated from the equivalentdiameter o
26、f the fibers. See 8.1.5; and (4) for modified colddrawn wire fibers, Type V, specified by a range of equivalentdiameters, the area of each individual fiber calculated from themeasured length and mass weight of the fiber. See 8.1.6. Theultimate tensile load in newtons pounds-force for individualfiber
27、s shall be measured to at least three significant figures.Testing shall be in accordance with Test Methods and Defini-tions A 370, where applicable.7.2 Bending Requirements:7.2.1 Fibers shall withstand being bent around a 3.2 mm0.125 diameter pin to an angle of 90 at temperatures not lessthan 16C 60
28、F 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 the scope of this specification; seeACI 5
29、44.1R.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 4 500 kg 5 tons of material.At least 90 % of the specimens must pass the test.8
30、. 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-drawn wire (Type I) fibers are speci-fie
31、d 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 be computed as:l5l / dewhere:A = tw, and
32、de= 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 =4A / p.8.1.5 Melt-extracted (Type III)
33、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 mass weight of aA 820/A 820M 062known quantity of fibers, based upon 7 865 kg/m30.284lb/in.3 measured to the nea
34、rest 0.1 mg 2 x 10-6lb. 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 spefi-cied by a range of equivalent diameters, (de-r), and length (l), ornominal length (ln). Equivalent diameter is computed as in8.1.5. A range of
35、 nominal apsect ratios, (ln-r) can be computedas follows:ln2r5 l / de2r, or 5 ln/ de2r.NOTE 3Specifying a specific diameter or equivalent diameter forType V fibers is not applicable as the diameters of many Type V fibersvary more than 6 10 % in each lot. Therefore a user should provide thelimits on
36、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 % of the specimens in each test shall me
37、et thespecified tolerances for length, diameter or equivalent diam-eter, and aspect ratio.8.2.2 At least one test shall be performed for 4 500 kg 5tons of finished product.8.3 Permissible Variations:8.3.1 The length, or nominal length shall not vary from itsspecified value more than 610 %.8.3.2 The
38、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, Finish, and Appearance9.1 Surface Cond
39、ition: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 coatings shall not be causefor rejection prov
40、ided that the individual fibers separate whenmixed in concrete in accordance with Specification C 1116,and tensile and bending properties are not less than therequirements of this specification.10. Inspection10.1 Unless otherwise specified in the purchase order orcontract, the manufacturer is respon
41、sible 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 requirements speci-fied herein unless disapp
42、roved 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 Rehearing11.1 Rejection:11.1.1 If any test fa
43、ils 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 manufacturer notified.11.1.2 Rejection of fibers shal
44、l 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 meet the require-ments of tension, bending,
45、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.12. Certification12.1 Certificate of Complia
46、nceWhen 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 any otherrequirements designated in the purchas
47、e 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 year of issue), and any other requirements d
48、esig-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 document is responsible for itscontent.12.4 C
49、opies 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 Package Marking13.1 Packaging, marking, and loa
