1、Designation: A820/A820M 15A820/A820M 16Standard 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
2、 last revision. 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 for steel fibers intended for use in fiber-reinforced concrete. Five
3、types ofsteel fibers for this purpose are defined as pieces of smooth or deformed cold-drawn wire; smooth or deformed cut sheet;melt-extracted fibers; mill-cut or modified cold-drawn wire steel fibers that are sufficiently small to be dispersed at random in aconcrete mixture.1.2 This specification p
4、rovides for measurement of dimensions, tolerances from specified dimensions, and required minimumphysical properties, and prescribes testing procedures to establish conformance to these requirements.1.3 In the case of conflict between a requirement of a product specification and a requirement of thi
5、s specification, the productspecification shall prevail. In the case of a conflict between a requirement of the product specification or a requirement of thisspecification and a more stringent requirement of the purchase order, the purchase order shall prevail. The purchase orderrequirements shall n
6、ot take precedence if they, in any way, violate the requirements of the product specification or thisspecification; for example, by the waiving of a test requirement or by making a test requirement less stringent.1.4 The values stated in either SI units or inch-pound units are to be regarded separat
7、ely as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.2. Referenced Documents2.1 The following documents, of the issue in eff
8、ect on the date of material purchase, form a part of this specification to the extentreferenced herein.2.2 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testing of Steel ProductsA700 Guide for Packaging, Marking, and Loading Methods for Steel Products for ShipmentC1116/C1116M Spec
9、ification for Fiber-Reinforced Concrete2.3 ACI Documents:3ACI 506.1 Guide to Fiber-Reinforced ShotcreteACI 544.1R Committee Report on Fiber-Reinforced Concrete2.4 U.S. Federal Standards:4Fed. Std. No. 123 Marking for Shipment (Civil Agencies)2.5 U.S. Military Standards:4MIL-STD-129 Marking for Shipm
10、ent and Storage3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 deformed fiber, na fiber that is bent, flattened, or roughened to improve mechanical bond to the concrete matrix.3.1.2 modified fiber, na cold-drawn wire fiber whose cross-section has been changed from circular by
11、shaving the wire.1 This specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee A01.05on Steel Reinforcement.Current edition approved Dec. 1, 2015June 1, 2016. Published January 2015June 2016. Originall
12、y approved in 1985. Last previous edition approved in 20112015 asA820/A820M 11.A820/A820M 15. DOI: 10.1520/A0820_A0820M-15. 10.1520/A0820_A0820M-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standar
13、dsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American Concrete Institute (ACI), P.O. Box 9094, Farmington Hills, MI 48333-9094, http:/www.concrete.org.4 Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Rob
14、bins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict al
15、l changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 1
16、00 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.3 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 limits placed on the equivalent diameter by the specifier. See 8.1.6 and Note
17、3.3.2 SymbolsThe following symbols used in this specification are defined as follows:A = cross-sectional area, in.2 mm2d = diameter, in. mmfu = ultimate tensile strength, psi MPal = length, in. mm = l/ d = aspect ratio3.2.1 The subscript n on dimensional units indicates “nominal” and the subscript e
18、 indicates “equivalent.” “Nominal” and“equivalent” dimensions are calculated from other measurable dimensions or average weight mass.4. Classification4.1 Five general types of steel fibers are identified in this specification based upon the product or process used as a source ofthe steel fiber mater
19、ial.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 Orders for steel fibers under this specification shall contain the following in
20、formation:5.1.1 Quantity in pounds or tons kilograms,5.1.2 Type or types permissible (4.1),5.1.3 Diameter or equivalent diameter (8.1.4), or range of equivalent diameters (8.1.6),5.1.4 Length or nominal length (3.1.3),5.1.5 Deformations, if required,5.1.6 Whether certification by the manufacturer is
21、 required including whether a report is to be furnished (Section 11), and5.1.7 ASTM designation and year of issueNOTE 1For information on satisfactory sizes and aspect ratios, see ACI 544.1R and ACI 506.1, and contact the manufacturers regarding availability.6. Materials and Manufacture6.1 The mater
22、ials and manufacturing methods used shall be such that the fibers produced conform to the requirements in thisspecification.7. Mechanical Properties7.1 Tensile Requirements:7.1.1 At least ten individual tensile tests of randomly selected finished fibers shall be performed for each 5 tons 4 500 kg of
23、product. This is an approximate distribution of one fiber tensile test per every 0.5 ton 450 kg of finished product. The averagetensile strength, fu, of each fiber shall not be less than 50 000 psi 345 MPa. The tensile strength of any one of the ten specimensshall not be less than 45 000 psi 310 MPa
24、. Where the parent source material consists of sheet or wire, tensile tests by themanufacturer may be performed on larger samples of source material. One sample of each different source material used shall thenbe tested for each 5 tons 4 500 kg of material. The tensile strength of a single sample of
25、 source material shall not be less than50 000 psi 345 MPa.7.1.2 The cross-sectional area used to compute fu shall be carried out to five decimal places, in units of square inches squaremillimetres, and shall be: (1) for drawn wire fibers, Type I, the area calculated from the actual diameter of the p
26、arent sourcematerial or finished fiber; (2) for cut sheet fibers, Type II, the area calculated from the actual thickness and width of the parentsource material specimen, or if fibers are tested, the area of each individual fiber calculated from measured length and weightmass of the fiber. See 8.1.5.
27、 (3) for melt-extracted fibers, Type III,or mill-cut fibers, Type IV, specified by equivalent diameter,the area calculated from the equivalent diameter of the fibers. See 8.1.5; and (4) for modified cold drawn wire fibers, Type V,specified by a range of equivalent diameters, the area of each individ
28、ual fiber calculated from the measured length and weightmass of the fiber. See 8.1.6. The ultimate tensile load in pounds-force newtons for individual fibers shall be measured to at leastthree significant figures. Testing shall be in accordance with Test Methods and Definitions A370, where applicabl
29、e.7.2 Bending Requirements:A820/A820M 1627.2.1 Fibers shall withstand being bent around a 0.125 in. 3.2 mm diameter pin to an angle of 90 at temperatures not less than60F 16C without breaking.NOTE 2The bending requirements of this specification provide a general indication of fiber ductility, as may
30、 be important in resisting breakage duringhandling and mixing operations. Ductility measures of fiber-reinforced concrete are outside the scope of this specification; see ACI 544.1R.7.2.2 Bend tests shall be conducted on ten randomly selected specimens of finished fibers. It shall be permissible to
31、performbend tests manually. At least one test consisting of ten specimens shall be made for each 5 tons 4 500 kg of material. At least90 % 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 specified by diamet
32、er (d) or equivalent (de) and length (l), that establish aspecified aspect ratio, (), or (e), as (l / d) or (l / de).8.1.2 Deformed cold-drawn wire (Type I) fibers are specified by the diameter (d) or equivalent diameter (de) and nominal lengthafter bending (ln). Nominal aspect ratio (n) is establis
33、hed 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 () can be computed as:5l/dewhere:A = tw, andde = equivalent diameter 5=4A/pi .8.1.4 Deformed cut sheet (Type II) fibers are specified by thickness (t), width (w), and
34、 nominal length after deformation (ln).Nominal aspect ratio (n) can be computed as follows.5ln/dewhere:A = tw, andde = equivalent diameter 5=4A/pi .8.1.5 Melt-extracted (Type III) and mill-cut (Type IV) fibers are specified by equivalent diameter, (de), and length (l), or nominallength (ln). Equival
35、ent diameter is computed from measured average nominal length and the weight mass of a known quantityof fibers, based upon 0.284 lb/in.3 7 865 kgm3 measured to the nearest 2 10-6 lb 0.1 mg. Nominal aspect ratio, (n), canbe computed as follows:n5l/de, or5ln/de8.1.6 Modified cold-drawn wire fibers (Ty
36、pe V) are specified by a range of equivalent diameters, (de-r), and length (l), ornominal length (ln). Equivalent diameter is computed as in 8.1.5. A range of nominal aspect ratios, (n-r) can be computed asfollows:n2r5l/de2r, or5ln/de2rNOTE 3Specifying a specific diameter or equivalent diameter for
37、Type V fibers is not applicable as the diameters of many Type V fibers vary morethan 610 % in each lot. Therefore a user should provide the limits on diameter or equivalent diameter allowable.8.2 Measurement of Dimensions:8.2.1 Measurement of dimensions shall be performed on not less than 10 randoml
38、y selected specimens for each test to establishthe average for conformance to specified tolerances.At least 90 % of the specimens in each test shall meet the specified tolerancesfor length, diameter or equivalent diameter, and aspect ratio.8.2.2 At least one test shall be performed for 5 tons 4 500
39、kg of finished product.8.3 Permissible Variations:8.3.1 The length, or nominal length shall not vary from its specified value more than 610 %.8.3.2 The diameter, equivalent diameter, or range of equivalent diameters shall not vary from its specified value more than610 %.8.3.3 The aspect ratio, nomin
40、al aspect ratio, or range of aspect ratios shall not vary from its specified value more than 615 %.9. Workmanship, Finish, and Appearance9.1 Surface Condition:9.1.1 Seams and surface irregularities shall not be cause for rejection provided that tensile properties are not less thanrequirements of thi
41、s specification and mixing performance in concrete is not adversely affected.9.1.2 Rust, mill scale, or other coatings shall not be cause for rejection provided that the individual fibers separate when mixedin concrete in accordance with Specification C1116/C1116M, and tensile and bending properties
42、 are not less than the requirementsof this specification.A820/A820M 16310. Inspection10.1 Unless otherwise specified in the purchase order or contract, the manufacturer is responsible for the performance of allinspection and test requirements specified herein. Except as otherwise specified in Inspec
43、tion of the steel fibers shall be agreedupon between the purchaser and the manufacturer as part of the purchase order or contract, the manufacturer may use his own orany other suitable facility for the performance of the inspection and test requirements specified herein unless disapproved by thepurc
44、haser. The purchaser shall have the right to perform any of the inspections and tests set forth in this specification where suchinspections are deemed necessary to ensure that material conforms to prescribed requirements.contract.11. Rejection and Rehearing11.1 Rejection:11.1.1 If any test fails to
45、conform to the requirements of this specification, it shall be cause for rejection of the materialrepresented by the test. Material that is found to be defective subsequent to its acceptance at the manufacturers works may berejected, and the manufacturer notified.11.1.2 Rejection of fibers shall be
46、reported to the manufacturer promptly and in writing. Samples representing fibers rejectedby the purchaser shall be preserved until disposition of the claim has been agreed to between the supplier and the purchaser.11.2 RehearingWhen any test fails to meet the requirements of tension, bending, or di
47、mensional tolerances, a retest shall beallowed. This retest shall be performed on twice the number of randomly selected specimens originally tested. The results of theretest shall meet the requirements of this specification or the lot shall be rejected.12. Certification12.1 Certificate of Compliance
48、When specified in the purchase order or contract, the producer or supplier shall furnish acertificate of compliance stating the product was manufactured, sampled, tested, and inspected in accordance with this specification(including year of issue) and any other requirements designated in the purchas
49、e order or contract, and has been found to meet suchrequirements.12.2 Test ReportsWhen specified in the purchase order or contract, test reports shall be furnished to the purchaser containingthe results of all tests required by this specification (including year of issue), and any other requirements designated in the purchaseorder or contract.12.3 A signature or notarization is not required; however, the document shall clearly identify the organization submitting thedocument. Notwithstanding the abse
