1、Designation:A911/A911M05 Designation: A911/A911M 11Standard Specification forUncoated, Stress-Relieved Steel Bars for PrestressedConcrete Railroad Ties1This standard is issued under the fixed designation A911/A911M; the number immediately following the designation indicates the yearof original adopt
2、ion or, in the case of revision, the year of 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 uncoated stress-relieved steel bars for use in
3、 prestressed concrete railroad ties.1.2Supplement I describes low-relaxation bars and relaxation testing for that product. Low-relaxation bars shall be furnishedwhen specifically ordered, and may be furnished in place of regular bars if mutually agreed to by the purchaser and manufacturer.1.2 A supp
4、lementary requirement (S1) is provided for use where low-relaxation bars and relaxation testing for that product isrequired by the purchaser. The supplementary requirement applies only when specified in the purchase order or contract.1.3 This specification is applicable for orders in either inch-pou
5、nds units (as Specification A911) or in SI units (as SpecificationA911M).1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standards. Within the text, the SIunits are shown in brackets. The values stated in each system are not exact equivalents; therefore,
6、 each system must be usedindependently of the other. Combining values from the two systems may result in nonconformance with the specification.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testing of Steel ProductsE328 Test Methods for Stress Relaxation
7、for Materials and Structures2.2 Federal Standard:3Fed. Std. No. 123Marking for Shipments (Civil Agencies) Fed. Std. No. 123 Marking for Shipments (Civil Agencies)2.3 Military Standards:3MIL-STD-129Marking for Shipment and Storage3MIL-STD-163Steel Mill Products Preparation for Shipment and Storage3Ma
8、rking for Shipment and Storage3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 lot, nall the coils of bars of the same nominal bar size contained on an individual shipping release or shipping order,from the same cast or heat of steel.4. Ordering Information4.1 It shall be the r
9、esponsibility of the purchaser to specify all requirements that are necessary for bars ordered to thisspecification. Such requirements shall include, but are not limited to, the following:4.1.1 Quantity (weight) mass,4.1.2 Name of material (uncoated, stress-relieved bars for prestressed concrete rai
10、lroad ties),4.1.3Diameter of bar (inches) millimetres,4.1.4Packaging,4.1.5ASTM designation and year of issue, and1This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.05on Steel Reinforcem
11、ent.Current edition approved May 1, 2005. Published May 2005. Originally published in 1992. Last previous edition approved in 2002 as A911/A911M02. DOI:10.1520/A0911_A0911M-05.Current edition approved Jan. 15, 2011. Published February 2011. Originally published in 1992. Last previous edition approve
12、d in 2005 as A911/A911M 05. DOI:10.1520/A0911_A0911M-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3Av
13、ailable from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.19111-5098,http:/dodssp.daps.dla.mil.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what cha
14、nges have been made to the previous version. Becauseit may not be technically possible to adequately depict all 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 offi
15、cial document.*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.4.1.6Special requirements, if any.NOTE1A typical ordering description is as follows: 100 tons 90 t uncoate
16、d, stress-relieved steel bars for prestressed concrete railroad ties, 0.394-in.10-mm diameter bars in 6.5-ft 2.0-m diameter coils to ASTM AXXX AXXXM.4.1.3 Nominal diameter of bar (inches) millimetres,4.1.4 Inspection (Section 12),4.1.5 Load-elongation curve (14.2),4.1.6 Core diameter and length of c
17、oils (15.1),4.1.7 Packaging,4.1.8 Supplementary Requirement S1 (if desired), and4.1.9 ASTM designation and year of issue.5. Manufacture5.1 The bars shall be made from properly identified heats of steel made by the electric-furnace, the open-hearth, or thebasic-oxygen process.5.2 After hot-rolling, t
18、he bars shall be cold-drawn and finally stress-relieved by induction heat treatment to produce the desiredmechanical properties and then coiled.6. Chemical Requirements6.1 An analysis of each heat of steel shall be made by the manufacturer from test samples taken during the pouring of each heat.6.2
19、The analysis of the steel shall conform to the chemical requirements specified in Table 1.7. Mechanical Requirements Mechanical Property Requirements7.1 Test MethodTests shall be made in accordance with Test Methods and Definitions A370, including Annex A4, usingfull-size bar specimens taken from ei
20、ther end of the coil of the finished product.7.2 Tensile StrengthThe minimum tensile strength of the finished bar, as represented by test specimens, shall conform to therequirements prescribed in Table 2.7.3 Yield StrengthYield strength shall be measured at 1 % extension under load. The load at this
21、 extension is recorded as yieldstrength and shall meet the requirements of Table 2.7.4 ElongationThe total elongation after rupture shall not be less than 6.0 % and shall be measured in a gage length of 4 in.100 mm.7.5 Wrapping TestBars shall withstand being wound around a mandrel with a diameter of
22、 five times the bar diameter withoutcracking or other surface defects occurring on the outside of the bent portion. The bar shall be bent around the mandrel 1-12 turnsbeginning with a 90 bend.8. Dimensions and Permissible Variations8.1 The size of the finished bar shall be expressed as the nominal d
23、iameter of the bar in decimals of an inch millimetere. Therequired initial diameters before cold-drawing, and the final diameters after cold-drawing shall be as follows:Initial Diameter Final Diameter0.591 in. 15 mm 0.370 in. 9.4 mm0.614 in. 15.6 mm 0.394 in. 10 mm0.654 in. 16.6 mm 0.413 in. 10.5 mm
24、TABLE 1 Chemical RequirementsElement Composition, %Carbon 0.700.90ASilicon 0.100.35Manganese 0.500.90BChromium, max 0.15Phosphorus, max 0.030Sulphur, max 0.035Copper, max 0.30ACarbon in any one lot shall not vary more than 0.13 %.BManganese in any one lot shall not vary more than 0.30 %.A911/A911M 1
25、128.2 Permissible Variations in Diameter:8.2.1 All bars shall conform to a size tolerance of 60.002 in. 60.05 mm from the nominal diameter.8.3 Out-of-RoundThe difference between the largest and smallest diameter, measured at the same section, shall not be greaterthan 0.002 in. 0.04 mm.TABLE 2 Mechan
26、ical RequirementsYield strength, min 200 ksi 1375 MPaTensile strength, min 228 ksi 1570 MPaRatio of yield strength to tensile strength, max 0.95Elongation after rupture in a gage length of 4 in.100 mm, min6.0 %Reduction of area, min 30.0 %A911/A911M 1130.002 in. 0.05 mm.9. Workmanship, Finish, and A
27、ppearance9.1 Joints:9.1.1 There shall be no welds or joints in the finished bar. Any welds or joints made during manufacture to promote continuityof operations shall be removed.9.2 The finished bar shall be uniform in diameter in conformance with Section 8 and shall be free of imperfections not cons
28、istentwith good commercial practice.9.3 StraightnessAfter uncoiling, there shall be no residual out-of-line deformation greater than 0.4 in. 10 mm in a lengthof 40 in. 1000 mm.10. Sampling10.1Test specimens taken from either end of the coil are permitted. Any specimen found to contain a joint shall
29、be discardedand a new specimen obtained.10.1 Test specimens taken from either end of the coil are permitted.11. Number of Tests11.1 One test specimen each for the tensile test and the wrapping test shall be taken for each 10 coils or fraction thereof in alot.12. Inspection12.1 The purchaser shall be
30、 allowed to request that a representative inspect or witness the inspection and testing of the materialprior to shipment. Such agreement shall be made by the purchaser and manufacturer as part of the purchase order or contract.12.2 When such inspection or witness of inspection and testing is agreed
31、upon, the purchasers representative shall be affordedreasonable access to facilities to assure that the material meets the requirements of this specification. Inspection and tests shall beconducted so as to avoid unnecessary interference with the manufacturers operations.13. Rejection and Rehearing1
32、3.1 Failure of any test specimen to comply with the requirements of this specification shall constitute grounds for rejection ofthe lot represented by the specimen.13.2 The manufacturer shall be allowed to resubmit the lot for inspection by testing a samplespecimen from each reelcoil andsorting out
33、nonconforming material.13.3 In the event that testing of any individual samplespecimen results in a reasonable doubt as to the ability of the bar to satisfyany requirement of this specification, two additional tests shall be made on samplesspecimens of bar from the same reel,coil, andif failure occu
34、rs in either of these tests, the represented coil shall be rejected.14. Certification14.1 In the event that outside inspection is waived, a manufacturers certification that the material has been tested in accordancewith and meets the requirements of this specification shall be the basis of acceptanc
35、e of the material.14.2 The manufacturer shall, when requested in the order, furnish a representative load-elongation curve for each size shipped.14.3 A material test report, certificate of inspection, or similar document printed from or used in electronic form from anelectronic data interchange (EDI
36、) transmission shall be regarded as having the same validity as a counterpart printed in thecertifiers facility. The content of the EDI transmitted document must meet the requirements of the invoked ASTM standard(s) andconform to any existing EDI agreement between the purchaser and the supplier. Not
37、withstanding the absence of a signature, theorganization submitting the EDI transmission is responsible for the content of the report.NOTE2The 1The industry definition as invoked here is: EDI is the computer-to-computer exchange of business information in a standard formatsuch as ANSI ASC X12.15. Pr
38、oduct Marking and Packaging15.1 The bars shall be furnished in coils having a minimum core diameter of 6.5 ft 2.0 m, for bars of 0.370 in. 9.4 mmdiameter and a minimum core diameter of 8.0 ft 2.4 m for bars of 0.394 in. 10 mm and 0.413 10.5 mm diameter, unlessotherwise specified by the purchaser. Le
39、ngths of coils shall be as agreed upon at the time of purchase. Each coil shall be identifiedwith two strongdurable tags securely attached showing the length, size, grade, ASTM designation, and the name or mark of themanufacturer.15.2 Low-relaxation bars produced in accordance with the requirements
40、of Supplement I supplementary requirement (S1) shallbe specially identified.15.3For Government Procurement Only When 15.3 When specified in the contract purchase order or order,contract, and fordirect procurement by or direct shipment to the United StatesU. S. government, material shall be preserved
41、, packaged, and packedA911/A911M 114marking for shipment, in accordance with the addition to requirements of MIL-STD-163. The applicable levels shall be as specifiedin the contract. Marking for shipment of such material purchase order or contract, shall be in accordance with Fed. Std. No. 123for use
42、 by civil agencies and MIL-STD-129 for use by military agencies.16. Transportation and Storage16.1 The bars shall be well-protected using good commercial practice against mechanical injury and contamination in shippingas mutually agreed upon by the purchaser and manufacturer at the time of purchase.
43、 The coils shall not be exposed to weatherduring transportation or storage. Storage areas shall be free from aggressive elements such as chlorides, nitrates, fertilizers, acids,or other deleterious materials.16.2 Corrosion-preventing coatings shall be allowed to be used to afford protection against
44、corrosion, but assurance shall bemade that the corrosion inhibitor can be removed with suitable solvents by the purchaser. Steel with rust, which can be removedwith a soft, dry rag,cloth, shall not be cause for rejection. Steel with pitted rust shall be subject to rejection.17. Keywords17.1prestress
45、ed concrete; railroad ties; steel bars, stress-relieved17.1 low-relaxation bars; prestressed concrete; railroad ties; steel bars, stress-relievedSUPPLEMENTARY REQUIREMENTSI. LOW-RELAXATION BARSS1 ScopeS1.1This supplement delineates only those details that are peculiar to low-relaxation bars, and to
46、the methods of relaxationtesting related to bars having properties generally as described in Specification A911/A911M.S2 Test MethodS2.1Low-relaxation bars shall be tested as prescribed in MethodS1. LOW-RELAXATION BARS AND RELAXATION TESTINGThe following supplementary requirement shall apply only wh
47、en specified in the purchase order orcontract.S1.1 ScopeS1.1.1 This supplementary requirement delineates only those details that are peculiar to low-relaxation bars, and to the methodsof relaxation testing related to bars having properties generally as described in Specification A911/A911M.S1.2 Test
48、 MethodS.1.2.1 Low-relaxation bars shall be tested as prescribed in Test Methods E328.S1.3 Relaxation PropertiesS1.3.1 Low-relaxation bars shall meet the mechanical property requirements of this specification, with the added requirementslisted in Table 3S1.1.S1.4 Yield StrengthS1.4.1 Yield strength
49、of low-relaxation bars, as described in 7.3, shall not be less than 90 % of the specified minimumbreakingtensile strength of the bar.S1.5 Conditions of Relaxation TestS1.5.1 If required, relaxation evidence shall be provided from the manufacturers records of tests on similarly dimensioned bars.TABLE S1.1 Relaxation Requirementsfpi/fpuAMax Stress Losses after 1000 h, %0.50 1.00.60 1.00.70 2.50.80 5.0Afpi= initial prestress load, andfpu= specified minimum tensile strength.A911/A911M 115S1.5.2 The
