JP2020537072A - Reinforcing wire with spiral contour - Google Patents

Abstract

The present invention can be used to produce prestressed rebar for concrete reinforcements, maximally strong adhesion to concrete in any potentially possible displacement direction, and high levels. Provides specific strength, relaxation resistance and fatigue resistance. In a reinforcing wire with a spiral contour, three line planes separated from each other by the cross section of the cylindrical surface are applied to the surface of the wire along the spiral line. The trapezoidal protrusions are arranged on the line plane that is inclined in the direction opposite to the direction of the spiral line on which the line line surface itself is placed.

Description

The present invention relates to wire drawing manufacturing to obtain prestressed (steel wire reinforced) reinforcement intended to reinforce hollow core slabs formed without the use of formwork and other concrete articles. Can be used.

Reinforcing wires with a circular cross section are known, the surface of which is applied with a periodic contour in the form of a rounded depression under a cylindrical surface generator, the depressions in two longitudinal directions on either side of the surface. Arranged in a row (see GOST 7348-81 "Carbon Steel Wires for Reinforcement of Current Concrete Structures").

The drawbacks of known reinforcing wires are low specific strength, fatigue resistance, and relaxation resistance, due to the presence of stress concentration in the transition region of the periodic contour, which reduced the cross-sectional area. Placed in the area.

Another drawback of known reinforcing wires is their poor adhesion to concrete.
This factor is due to the very shallow depth of the periodic cavities and the narrow angle of inclination of the edges of these cavities with respect to the wire axis, resulting in the wire being Poisson while applying the working tension of the wire. When narrowed, the concrete protrusions formed when filling the periodic cavities on the wire surface lose their adhesive bond to the cavities, while at the same time longitudinal forces are applied in the plane of the wide area of the wire between the cavities. It will be loaded.
In this case, it should be noted that the generation of more developed contours in this structure ensures further weakening of the cross section and increase of stress concentrators.

The closest prior art of the reinforcing wire according to the present invention is a reinforcing wire with a spiral contour, which has an all-circular cross section with four trapezoidal protrusions, the outward surface portion of which is the main surface of the reinforcing wire. Along with a circular concentric arc, the protrusions are spirally arranged above the main surface and are continuous along the entire length of the wire (see Standard of GB / T 5223 of the People's Republic of China).

This structure of the reinforcing wire has higher specific strength, fatigue resistance, and relaxation resistance due to its uniform cross section along its entire length, which results in the static process of pressure forming. It means that the properties obtained are uniform along the length.
Also, the known structure of the wire has a higher contour height and a larger relative crushed area, resulting in stronger adhesion to the concrete, but as a whole, the concrete is limited by the height of the protrusions. Due to its volume, the adhesive strength to concrete does not increase.
Here, the cylindrical surface facing the outside of the protrusion is only involved in bonding and frictional coupling, as well as the possibility of spiral displacement of the wire in the concrete by its own impress, without breaking itself.

An object of the present invention is to simultaneously provide mechanical adhesion in any potentially possible displacement direction, and maximum strong adhesion to concrete, including high levels of specific strength, relaxation resistance and fatigue resistance. To develop the structure of the wire.

The object of this is that the reinforcing wire with a spiral contour according to the invention has a triangular cross section with rounded angles, ribs and wire surfaces, which are formed by the rounded angles and sides of the triangle, respectively. It is achieved by forming periodic contours in the form of inclined trapezoidal protrusions, which are spirally arranged and have rounded transition regions, on the surface of the surface along their positioning lines.

Also, the reinforcing wire can have a quadrangular or elliptical cross section with a rounded angle.

Further, the surface of the wire surface may be both a linear surface and a convex or concave surface.

Such a wire design provides the transmission of tension to the concrete by means of the normal stress of the bearing capacity caused by the wedges on the spiral sides that are inclined with respect to the axis of the wire, and the reinforcing rope to the concrete. Adhesion studies have demonstrated the safety and exceptional effectiveness of this method for the practice of adhesions;
For example, when loading a hollow core slab formed without the use of a mold, reinforced with ropes at three edges, the strength of the rope is equal to the number of ropes, the cross section of the rope, the strength and the actual tension. The slab was destroyed because it was completely depleted under a load 25-35% higher than the same slab reinforced with a set of standard ropes.

In this case, the presence of a periodic contour on the helicoid of the reinforcing wire prevents it from slipping through its own impress in the concrete, forming a periodic contour in the form of protrusions on the surface. Prevents cross-section weakening where it is placed and transfers stress concentration to the reinforced area by increasing the cross-section.

Hereinafter, the present invention will be described with reference to the drawings.
Figure 1 schematically shows the appearance of a reinforcing wire with a spiral contour; FIG. 2 schematically shows a cross section of a reinforcing wire having a spiral contour.

Reinforcing wires having a spiral contour according to one of the embodiments of the present invention are shown in FIGS.
On the surface of the wire 1 (FIGS. 1 and 2), three line-of-sight surfaces 2 separated from each other by the region of the cylindrical surface 3 are provided along the spiral line.
The trapezoidal protrusion 4 is arranged on the line surface 2 which is inclined in a direction opposite to the direction of the spiral line for positioning the line surface 2 itself.

Reinforcing wires are manufactured, for example, as follows. A wire 1 having a circular cross section is manufactured in advance. The wire then has a roller cartridge that rotates around it, wherein the roller cartridge has three sloping rollers, the rollers having a cylindrical working surface with sloping grooves cut out. Supplied through.

Further, on the surface of the wire 1, the line-of-sight surface 2 is spirally formed by the action of a cylindrical roller, and a trapezoidal protrusion 4 is formed on the cylindrical surface of the roller where a groove is formed. , Are formed facing each other. The area of the cylindrical surface 3 is maintained in the portion of the wire surface that is not deformed by the rollers.

Reinforcing wires manufactured at the same time as the process of shape change are produced by any known method, for example, between two capstans, each of which is a set consisting of a drive pulley (also called a pulley) and a non-drive pulley. , Or between the two drive pulleys, is pulled to a force of 30-70% of the breaking force.

When the reinforcing wire is in linear tension, while passing through the first and second capstans, the reinforcing wire is heated to a temperature of 370-430 ° C, for example by means of an inductance furnace (also called a furnace), followed by Then, during the period between the first and second capstans, the tension wire is forcibly cooled by a water sprayer in a linear tension state.

When cooling is complete, the wire passes through a second capstan and is fed to the storage unit, from which the wire is either wound into a coil or fed to a cutting machine, where the wire reaches a certain length. Be disconnected.
The wire, which is then wound or cut to a specific length, is then packed by a known method.

Apart from the described method, the wire may undergo shape change by a single process run with a wire stretching operation.

1: Wire 3: Cylindrical surface 2: Linear surface 4: Trapezoidal protrusion

Claims (5)

A reinforcing wire with a spiral contour, having a triangular cross section with a rounded angle, a spiral cylindrical surface with the function of a rib and a wire surface that is a line of sight, which is a rounded angle. , A periodic contour in the form of an inclined trapezoidal protrusion with a rounded transition region, formed on the surface of the surface along the three wire planes, each spirally arranged, and their positioning lines. Reinforcing wire formed by. The reinforcing wire according to claim 1, wherein instead of a triangular cross section, the cross section has a quadrangular shape with a rounded angle. The reinforcing wire according to claim 1, wherein the cross section is elliptical instead of the triangular cross section. The reinforcing wire according to claim 1 to 3, wherein the surface is convex. The reinforcing wire according to claim 1 to 3, wherein the surface is concave.