CN2700437Y - Helical ribbed steel strand for prestressed concrete - Google Patents

Abstract

A helical ribbed steel strand for prestressed concrete is formed by spinning helical ribbed steel wires and belongs to ribbed steel products in the prestressed concrete structure used in the construction industry. The utility model is formed by spinning two, three and seven steel wires, and the steel wire for spinning the steel strand adopts a steel wire with helical ribs for spinning. The surface of the steel wire with helical ribs is provided with three to six parallel wound projected trapezoid-shaped helical ribs, the width of the helical rib is between 0.80 mm and 3.00 mm, the height of the helical rib is between 0.20 mm and 0.50 mm, and the helical lead is between 24 mm and 58 mm. The utility model overcomes the defects of poor bondability between standard steel strands and concrete and poor mechanical properties of notched steel strands and remains advantages of both the standard and the notched steel strands.

Description

Helix rib steel twisted wire for prestressed concrete

Technical field

The utility model belongs to building trade and is used for the steel strand that prestressed concrete member is made arrangement of reinforcement.

Technical background

The building trade prestressed concrete member, its intensity all adds steel wire or steel strand are made arrangement of reinforcement in order to increase.Steel strand in standard GB/T5224-2003 " steel strand for prestressed concrete " standard at present are indented steel stranded wires that the standard steel section twisted wire that is twisted into of round wire and indented wire are twisted into.

The standard steel section twisted wire that is twisted into by round wire, because it is smooth forming the Steel Wire Surface of steel strand, bond area between itself and the concrete, indented steel stranded wire and the concrete bond area of being made up of the same size indented wire is little, therefore, standard steel section twisted wire and concrete bond stress are also less; And indented wire is because compression chord influence in process of production, and its mechanical property is poor than round wire, so also relatively poor by the mechanical property of the indented steel stranded wire of indented wire twisting.

For overcome by the standard steel section twisted wire of round wire twisting and grip of concrete is poor, by the shortcoming of the indented steel stranded wire poor mechanical property of indented wire twisting, the utility model has designed a kind of steel strand that adopt the helix rib steel wire twisting, both improve the bond stress of steel strand, kept the good mechanical performance again.

Summary of the invention

The utility model is mainly realized by following structure

A kind of helix rib steel twisted wire has 2,3,7 steel wire twistings to form, and the steel wire of twisting steel strand adopts a kind of steel wire twisting that has spiral ribs.Helix rib steel wire is the surperficial trapezoid spiral rib that has 3～6 parallel projectioies that detour, its spiral rib width 0.8mm～3mm, and the high 0.2mm～0.5mm of spiral ribs, lead of screw is 24mm～58mm.

The steel strand of the utility model design are formed by two helix rib steel wire twistings, and its code name is 1 * 2H; Formed by three helix rib steel wire twistings, its code name is 1 * 3H; Formed by seven helix rib steel wire twistings, its code name is 1 * 7H.In 1 * 7H strand structure, its core wire can adopt helix rib steel wire or round wire.Described helix rib steel wire is for the surface has the trapezoid spiral rib of 3～6 parallel projectioies that detour, spiral rib width 0.80～3.00mm, the high 0.20～0.50mm of single rib, lead of screw 24～58mm.The trapezoid spiral rib of the parallel projection that detours in described helix rib steel wire surface, its trapezoidal base angle be (60 °～80 °) * 2, there is (0.10～0.50) * 135 ° chamfering at angles on trapezoidal two.

Employing meets YB/T146 " compressor wire and steel strand gren rod " standard, or the wire rod of YB/T170 " throwing with the non-steel wire rod that closes " standard is done raw material.Wire rod is after chemical analysis and metal lographic examination are qualified, carry out surfacing (pickling, phosphatization, saponification, dehydrogenation) → light circle drawing (drawing 5～10 roads, total draught 〉=70%) → spiral drawing (compression ratio≤15%) → twisting steel strand (1 * 2H, 1 * 3H, 1 * 7H) → stabilization processes (the heating in medium frequency tempering applies tension force, take-up) → finished product packing.Mechanical property meets GB/T5224-2003 " steel strand for prestressed concrete " standard.

Description of drawings

Below in conjunction with description of drawings, accompanying drawing 1 is 1 * 2H strand structure schematic diagram; Accompanying drawing 2 is 1 * 3H strand structure schematic diagrames; Accompanying drawing 3 is 1 * 7H strand structures, and its core wire is the helix rib steel wire schematic diagram; Accompanying drawing 4 is 1 * 7H strand structures, and its core wire is the round wire schematic diagram; Accompanying drawing 5 is helix rib steel wire profile schematic diagrames; Accompanying drawing 6 is helix rib steel wire cross-sectional view.In the accompanying drawings, Dn represents the steel strand diameter, and d represents helix rib steel wire nominal diameter, d ₁Expression helix rib steel wire outline circular diameter, d ₀Expression 1 * 7H strand structure core wire diameter, c represents the helix rib steel wire lead of screw, A is the steel strand measurement size, D ₁Expression helix rib steel wire base circle diameter (BCD).

The specific embodiment

1 * 2H strand structure as shown in Figure 1, promptly the helix rib steel wire by two same diameters forms by twisting.1 * 2H strand structure size and allowable variation, every meter reference mass should meet the regulation of table 1.Its structure is seen accompanying drawing 1, and steel wire cylindrical dotted line is steel wire outline circle, d ₁Be helix rib steel wire outline circular diameter, Dn is the steel strand diameter.

Table 11 * 2H strand structure size and allowable variation, every meter reference mass

Strand structure	Nominal diameter		Steel strand diameter allowable variation/mm	Steel strand are with reference to sectional area Sn/mm 2	Every meter steel strand reference mass/(g/m)
						Steel strand diameter Dn/mm	Steel wire diameter d/mm
	1×2H	6.00						2.80	+0.20 -0.08	12.31	97
8.00			3.75	22.08	173
		10.00				4.75	+0.25 -0.10	35.42		278
12.00			5.70	51.01	400
		14.00				6.65		+0.30 -0.12	69.43	545

1 * 3H strand structure as shown in Figure 2, promptly the helix rib steel wire by three same diameters forms by twisting.1 * 3H strand structure size and allowable variation, every meter reference mass should meet table 2 regulation.Its structure is seen accompanying drawing 2, d ₁Be helix rib steel wire outline circular diameter, A is the steel strand measurement size, and Dn is the steel strand diameter.

Table 21 * 3H strand structure size and allowable variation, every meter reference mass

Strand structure	Nominal diameter		Steel strand measurement size A/mm	Measurement size A allowable variation/mm	Steel strand are with reference to sectional area Sn/mm 2	Every meter steel strand reference mass/(g/m)
							Steel strand diameter Dn/mm	Pure diameter d/the mm of steel
	1×3H	6.50							2.80	5.60	+0.15 -0.05	18.46	145
8.60			3.75	7.47	+0.20 -0.10	33.18	260
		8.74						3.80	7.56	34.00	267
10.79			4.75	9.33		53.13	417
		12.95						5.70	11.20	76.51	601
15.11			6.65	13.07		+0.25 -0.15	104.14					817

1 * 7H strand structure such as accompanying drawing 3, shown in Figure 4 are promptly formed by twisting by seven steel wires.1 at the center that is distributed as of steel wire, 6 on every side, 6 steel wire diameter are identical on every side, are helix rib steel wire.The steel wire at center can be a helix rib steel wire, also can be round wire, its center steel wire diameter d ₀Steel wire diameter d adds and is not less than 2.5% on a large scale.1 * 7H strand structure, branch center are that helix rib steel wire and center are two kinds of round wires.When 1 * 7H strand structure center was helix rib steel wire, its steel strand size and allowable variation, every meter reference mass should meet table 3 regulation, and structure is seen accompanying drawing 3, d ₁Be helix rib steel wire outline circular diameter; When 1 * 7H strand structure center is round wire, its steel strand should be according to the bar number of rib height, rib width and the rib of steel strand center convolution rib steel wire with reference to sectional area, associative list 3 parameters are revised, and its every meter steel strand reference mass calculates according to revised sectional area.Its structure is seen accompanying drawing 4, d ₁Be helix rib steel wire outline circular diameter.

Table 31 * 7H strand structure size and allowable variation, every meter reference mass

Strand structure	Nominal diameter Dn/mm	Diameter allowable variation/mm	Steel strand are with reference to sectional area Sn/mm 2	Every meter steel strand reference mass/(g/m)	Core wire diameter d o adds on a large scale/and % is not less than
						1×7H	9.50	+0.30 -0.15	47.82	375	2.5％
11.10	56.68	445
			12.70	+0.40 -0.20	75.00		589
15.20	126.54	993
			15.70		134.66		1057
17.80	148.68	1167
			21.10		+0.42 -0.22		248.70	1952

Helix rib steel wire before the twisting, be the raw material wire rod through surfacing, carry out the drawing of 2～10 passage light circles, be processed into the surface by the particular manufacturing craft drawing again and have 3～6 parallel trapezoidal protruding spiral ribs that detour, the direction of spiral ribs is left-handed or dextrorotation, decides with the twisting direction of steel strand.Spiral rib width 0.80～3.00mm, the high 0.20～0.50mm of single rib, spiral ribs helical pitch 24～58mm.Trapezoidal base angle is (60 °～80 °) * 2, goes up the angle (0.10～0.50) * 135 ° chamfering is arranged for trapezoidal two.The mechanical property of the cold drawn helix rib steel wire before the twisting steel strand should meet GB/T5223-2002 " steel wires for prestressed concrete " standard.The helix rib steel wire profile is seen accompanying drawing 5, and its cross-sectional view is seen Fig. 6.

Theory analysis from the bond area and the bond stress of concrete and steel strand, helix rib steel twisted wire and concrete bond area, standard steel section twisted wire and concrete bond area than same size increase by 12%, thereby increase the bond stress of concrete and helix rib steel twisted wire; Because the spiral ribs on helix rib steel wire surface is continuous, its mechanical property is identical with round wire, so by the helix rib steel twisted wire of helix rib steel wire twisting with by the standard steel section twisted wire of round wire twisting, its mechanical property is also identical.

According to theory analysis, indented wire is because compression chord influence in process of production, its mechanical property is than round wire and helix rib steel wire poor mechanical property, and the mechanical property of the indentation steel hank knotting that is twisted into indented wire is than the poor mechanical property of standard steel section twisted wire and helix rib steel twisted wire.

The above analysis, the helix rib steel twisted wire is strong than standard steel section twisted wire and concrete bond stress, and the helix rib steel twisted wire is good than the mechanical property of indented steel stranded wire, and the helix rib steel twisted wire can improve the prestressed concrete member quality.

Use the helix rib steel twisted wire of the utility model design and the standard type of same size, promptly compare with the wire of round wire twisting, itself and concrete bond area increase by 12%, have kept original excellent mechanical performances, satisfy customer requirements.

Claims (2)

1 one kinds of helix rib steel twisted wires are formed by two, three, seven steel wire twistings, it is characterized in that the steel wire of twisting steel strand adopts a kind of steel wire twisting that has spiral ribs.

2 steel strand according to claim 1 is characterized in that helix rib steel wire is the trapezoid spiral rib that the surface has 3～6 parallel projectioies that detour, its spiral rib width 0.80mm～3.00mm, and the high 0.20mm～0.50mm of spiral ribs, lead of screw is 24mm～58mm.

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