1、Standard Specification for Wire Rope and Sockets for Movable Bridges AASHTO Designation: M 277-06 (2015) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001TS-4g M 277-1 AASHTO Standard Specification for Wire Rope and Soc
2、kets for Movable Bridges AASHTO Designation: M 277-06 (2015) 1. SCOPE 1.1. This specification covers steel wire rope for use in movable bridges. Both operating and counterweight ropes are included in nominal 6 19 rope construction. Suitable sockets are also included. 1.2. The values stated in SI uni
3、ts are to be regarded as the standard. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 102M/M 102, Steel Forgings, Carbon and Alloy, for General Industrial Use T 65M/T 65, Mass Weight of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy Coatings 2.2. ASTM Standards: A29/A29M, Standard Spec
4、ification for General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought A148/A148M, Standard Specification for Steel Castings, High Strength, for Structural Purposes A709/A709M, Standard Specification for Structural Steel for Bridges B6, Standard Specification for Zinc 2.3. ANSI Standard: B
5、4.1, American National Standards InstituteSockets, Pinholes, Pins 2.4. Military Standard: MIL-P-24216, Military SpecificationsFiber Polypropylene Cores for Wire Rope 3. TERMINOLOGY 3.1. acceptance breaking strengththe minimum ultimate strength value on which conformance to the specification shall be
6、 based. 3.2. bright wireswires in ropes that are uncoated. 3.3. centerthe inner or foundation member (wire or twisted fibrous material) in a strand around which the wires are laid. 3.4. circumferencethe measured perimeter of a circle circumscribing the wires of a strand or the strands of a wire rope
7、. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 277-2 AASHTO 3.5. corethe foundation member (a twisted fibrous material) of a wire rope around which strands are laid. 3.6. fibersthe material of
8、 which the centers or cores are made. 3.7. filler wiressmall diameter auxiliary wires for supporting and positioning main wires. Filler wires are included in the actual wire count and identification of the rope construction. 3.8. lang lay (See Figure 1.)the direction of lay of the wires in the stran
9、d and of the strand in the rope is the same. As a result, the rope has an appearance that the wires are diagonal to the axis of the rope. The wires and the strands may run to the right, “right lang lay” (commonly called “lang lay”) or to the left, “left lang lay” (on specific orders only). Figure 1L
10、ays in Wire Rope 3.9. layused by the wire rope industry in two different ways as follows: 3.9.1. The lay is the manner in which the wires in a strand or the strands in a wire rope lay (twisted). (See Figure 1.) 3.9.2. The lay is the distance parallel to the longitudinal axis in which a wire makes a
11、complete turn (spiral or helix) about the axis of the rope. It is also called the lay length or the pitch. (See Figure 2.) Figure 2Lay as a Unit of Measure 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law
12、.TS-4g M 277-3 AASHTO 3.10. nominal breaking strengththe value on which designs should be based. 3.11. ordered diameterthe nominal diameter of the circumscribing circle of a wire rope of strand. (See Figure 3.) Figure 3Determination of the Wire Rope Diameter 3.12. pitch (lay length)the distance para
13、llel to the longitudinal axis in which a wire makes a complete turn about the axis of the rope. 3.13. preformed stranda strand in which the wires are permanently shaped to the spiral form they assume in the strand. 3.14. preformed wire ropea wire rope in which the strands are permanently shaped to t
14、he spiral form they assume in the wire rope. 3.15. prestretchingstretching is the result of two components: the structural stretch, caused by the lengthening of the rope lay, compression of the core, and adjustment of the wires and strands to the load; and the elastic stretch caused by elongation of
15、 the wires. Prestretching is the application of a prescribed tensile force prior to delivery (see Section 5.2.4) intended to permanently adjust the rope for most of the structural stretch component, so that when it is placed in service the elastic stretch will be the only significant cause of additi
16、onal elongation. 3.16. regular laydesignates that the wires in the rope strand lay in one direction while the strand itself rotates in the rope in an opposite direction. The rope has, therefore, an outward appearance that all wires in the rope are roughly parallel to the longitudinal axis of the rop
17、e. There are two regular lays, as follows: 3.16.1. right regular lay (commonly called “regular lay”)the strands run in the rope downwards to the right (clockwise) while the wires in the strands rotate to the left (counterclockwise). This is the most used lay. 2015 by the American Association of Stat
18、e Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 277-4 AASHTO 3.16.2. left regular laythe strands in the rope run downwards to the left (counterclockwise) while the wires in the strand run to the right (clockwise). (See Figure 1.) The l
19、eft regular lay is not a commonly used lay and must be specifically ordered. 3.17. reels, manufacturingreels on which the strands and the wire ropes are wound in one continuous length as they are formed on the rope closing machine. 3.18. reels, shippingreels on which wire strands or wire ropes, cut
20、to the ordered lengths, are wound from the manufacturing reel for shipment. 3.19. ropea symmetrically arranged and helically twisted assembly of strands. 3.20. sockets type of wire fitting, including bridge sockets, which are steel castings with baskets for securing rope ends and equipped with adjus
21、table bolts. Closed type as “U-bolt” with or without a bearing block in the U of the bolt. Open type has two eyebolts and pin. 3.21. stranda symmetrically arranged and helically twisted assembly of wires. 3.22. 6 19 wire ropea common type of construction composed of six strands, each strand containi
22、ng an equal number of wires, ranging between 15 and 26. The six strands are helically twisted around a core of polypropylene, natural hard fiber, an independent wire rope, or a strand. Figure 4Components of Wire Rope 4. ORDERING INFORMATION 4.1. Orders for material under this specification shall inc
23、lude the following information: 4.1.1. Total length and individual lengths; 4.1.2. Nominal diameter; 4.1.3. Prestretched or non-prestretched, 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 277-5
24、 AASHTO 4.1.4. Construction (type of core, lay, etc.); 4.1.5. Galvanizing class and type, or bright; 4.1.6. Grade of rope; 4.1.7. Details on socket requirements; 4.1.8. AASHTO designation and date of issue; and 4.1.9. Special requirements: Mechanical tests, inspection, packaging requirements. Note 1
25、A typical ordering description is as follows: 2926 m (9600 ft), 38.1 mm (1.5 in.), improved plow steel, regular lay, in 732 m (2400 ft) spoolless packs to M 277, bright. Note 2Manufacturer should be advised to include sufficient materials to provide for the samples described in Section 7. 5. MATERIA
26、LS AND MANUFACTURE 5.1. Base MetalWire rope and strand shall be made of improved plow steel. The steel for wires shall be made by the basic oxygen or electric furnace processes. 5.2. Construction of Wire Rope: 5.2.1. The actual diameter of wire rope (the diameter of a circumscribed circle) shall be
27、measured when the rope is unstressed. The measurement shall be made as required in Section 10.1.2. The tolerance from nominal diameter of bright wire rope shall be 0 percent to +5 percent. 5.2.2. All ropes shall be preformed wire rope of 6 19 filler wire construction with a hard fiber or polypropyle
28、ne core. 5.2.3. Ropes shall be laid in accordance with the best practice. Every effort shall be made to obtain ropes of uniform physical properties. The ropes shall be fabricated in the greatest lengths practicable, and all similar ropes for any one bridge shall be cut from ropes manufactured with o
29、ne setting on one closing machine. 5.2.4. Prestretched rope shall meet the minimum modulus of elasticity shown in Table 1. 5.2.4.1. If specified, a test for modulus of elasticity shall be made on each manufactured length of wire rope. The modulus of elasticity shall be determined from a gauge length
30、 of not less than 50 diameters and shall be computed on the sum of the gross metallic cross-sectional areas of the wire making up the wire rope. Throughout the range from 10 percent of the strength listed in Table 6 to 90 percent of the prestretching tension, this modulus of elasticity shall not be
31、less than the specified minimum shown in Table 1. Table 1Minimum Modulus of Elasticity of Prestretched Structural Wire Rope Nominal Diameter Wire Rope, mm (in.) Minimum Modulus, GPa (psi) 12.763.5 (0.52.5) 138 (20,000,000) 5.2.4.2. PrestretchingEach rope shall be prestretched using the following pro
32、cedure: (1) Tension the rope to 40 percent of its ultimate tensile strength as determined in Section 7.5 and hold that load 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 277-6 AASHTO for 300 se
33、conds. (2) Reduce the load to 5 percent of the ultimate tensile strength. (3) Repeat this loadunload cycle two more times. (4) Release the load completely. 5.2.5. All wire ropes, unless otherwise specified, shall be right regular lay, and the maximum length of rope lay shall be as follows: Operating
34、 Ropes6.75 times nominal rope diameter Counterweight Ropes7.5 times nominal rope diameter The lay of the wires in the strands shall be such as to make the wires approximately parallel to the axis of the rope where they would come in contact with a circular cylinder circumscribed on the rope. 5.2.6.
35、Fiber core for wire rope shall be one of the hard fibers or polypropylene fiber. The hard fibers are manila (abaca) and sisal (African, Java, Mauritius, Mexican, and Yucatan). A mixture of two or more species of hard fibers may be used. Polypropylene fibers shall meet the requirements of MIL-P-24216
36、. Fiber core shall be of commercial quality and shall be thoroughly cleaned, free of waste, evenly twisted, of uniform plies, and of good workmanship. 5.2.6.1. Fiber cores and centers shall be thoroughly impregnated during fabrication with a lubricant that shall contain copper compounds or other pre
37、servation material to allay deterioration of fiber parts due to rot or mildew and shall not be injurious to steel wires. This requirement is not applicable to polypropylene cores or centers. 5.2.7. The wires of uncoated (not galvanized) steel wire ropes shall be thoroughly coated with a suitable lub
38、ricant during the process of manufacture. The lubricant shall have a mineral base compounded with additives designed to provide corrosion protection and lubricating qualities during shipping, storage, handling, and the initial period of service and suitable base for subsequent field re-lubrications.
39、 The lubricant shall be free from substances injurious to steel wires and fiber cores. 5.2.8. Coated (galvanized) steel wire ropes may be lightly lubricated during fabrication at the option of the manufacturer. 5.2.9. No splicing or joining of strands shall be permitted in the manufactured length of
40、 rope. Welds made prior to wire drawing are permitted. Joining of wires by welding during stranding operation is permissible and such joints shall be dispersed sufficiently so as to maintain the minimum tensile or breaking strength as listed in Table 2. Table 2Tensile Properties of Wire Diameters of
41、 Wire, mm (in.) Minimum Tensile Strength Uncoated,aGPa (psi) Minimum Elongation, percent 0.891.53 (0.0380.060) 1.65 (238,000) 1.50 1.542.54 (0.0610.100) 1.58 (230,000) 1.75 2.553.56 (0.1010.140) 1.55 (225,000) 2.00 3.574.83 (0.1410.190) 1.50 (218,000) 2.25 aFor galvanized wire deduct 10 percent of s
42、trength. 6. ZINC COATING 6.1. When specified to be zinc coated, the wire rope is normally furnished with Class A zinc-coated wire throughout. It may be furnished with Class B or Class C mass zinc-coated outer wires and Class A inner wires or Class B mass or Class C zinc-coated wires throughout where
43、 additional corrosion protection is required by the purchaser. The purchaser must specify such increase. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 277-7 AASHTO 6.1.1. The slab zinc, when us
44、ed, shall conform to ASTM B6 for Zinc, High Grade or better. 6.2. The weight of the zinc coating on the individual wires prior to the fabrication of the wire rope shall be not less than that specified in Table 3 for the class designated when tested in accordance with the stripping test of T 65M/T 65
45、. Table 3Minimum Weight of Coating Nominal Diameters of Coated Wire Mass of Zinc Coating, Minimum kg/m2(oz/ft2) of Uncoated Wire Surface mm. (in.) Class A Coating Class B Coating Class C Coating 1.021.55, incl (0.0400.061) 0.12 (0.40) 0.24 (0.80) 0.37 (1.20) 1.562.01, incl (0.0620.079) 0.15 (0.50) 0
46、.30 (1.00) 0.46 (1.50) 2.022.34, incl (0.0800.092) 0.18 (0.60) 0.37 (1.20) 0.55 (1.80) 2.352.62, incl (0.0930.103) 0.21 (0.70) 0.43 (1.40) 0.64 (2.10) 2.633.03, incl (0.1040.119) 0.24 (0.80) 0.49 (1.60) 0.73 (2.40) 3.043.61, incl (0.1200.142) 0.26 (0.85) 0.52 (1.70) 0.78 (2.55) 3.624.76, incl (0.143
47、0.187) 0.27 (0.90) 0.55 (1.80) 0.82 (2.70) 4.77 and largera(0.188) 0.30 (1.00) 0.61 (2.00) 0.92 (3.00) aThis is not to imply that larger wire will be manufactured to any unlimited diameter. It only implies that the wire sizes chosen by the wire rope manufacturer must meet the requirements of this sp
48、ecification. 6.3. The zinc-coated wire, prior to fabrication into wire rope, shall be capable of being wrapped two turns in a close helix at a rate exceeding 15 turns per minute around a cylindrical steel mandrel equal to five times the nominal diameter of the wire under test without cracking or fla
49、king the zinc coating to such an extent that any zinc can be removed by rubbing with the bare fingers. Note 3Loosening or detachment during the adherence test of superficial small particles of zinc formed by mechanical polishing of the surface of the coated wire shall not be considered cause for rejection. 6.4. Zinc coating shall be applied by either the electrolytic-plating process or by hot dipping in molten zinc as specified by the purchaser. 6.5. Zinc coating shall be free from uncoate
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