WO2021057940A1 - Npr spiral reinforcing bar - Google Patents

Abstract

Provided is an NPR spiral reinforcing bar (1); the outer surface of the NPR spiral reinforcing bar (1) is provided with a plurality of convex spiral ribs (2); the spiral ribs (2) have a spiral structure. The NPR spiral reinforcing bar (1) satisfies the characteristics of high uniformity and large deformation of the reinforcing bar and has good anchoring performance.

Description

NPR spiral reinforcement Technical field

The utility model relates to the technical field of concrete-related new materials, in particular to an NPR spiral steel bar.

Background technique

The new NPR material, after a specific chemical composition design, overcomes the local deformation and fracture of ordinary rebar and prestressed steel bars, and achieves both high strength and high toughness. The products of NPR new materials are mainly NPR spiral steel bars and NPR prestressed spiral steel bars, which are expected to be used in concrete components in the construction industry; in the field of concrete components, the bond strength between NPR spiral steel bars and concrete and resin is good or bad It is an important factor that determines its engineering service performance.

At present, the commonly used steel bars are hot-rolled rebars with crescent-shaped ribbed threads on the surface. The threads are longitudinal ribs and transverse ribs occluding teeth, and are discontinuous. The diameter of this rebar is between 6mm-50mm and is widely used Construction sector. Because the surface of the steel bar is equipped with longitudinal ribs, the bonding force and binding force with the concrete used in reinforced concrete projects are weak. When the reinforced concrete is under stress, the longitudinal ribs on the surface tend to make the concrete split to both sides. Cracks are not conducive to the occlusion between the concrete and the steel bars; the occlusal teeth of the transverse ribs are scattered and easy to squeeze and cut, and the anchoring force will be lost under large slip, and the anchoring ductility will be poor.

The existing crescent rib design of the threaded steel bar applied to the NPR spiral steel bar has the following disadvantages:

1) There is stress concentration at the root of the crescent-shaped rib in the diameter direction, and abnormal shear fracture is prone to occur during stretching, and the fracture elongation is uncontrollable;

2) The design of crescent-shaped ribs, in some application areas that require tail fastening, requires secondary thread processing on the tail of the steel bar. When tension is applied, it will appear below yield or just after yield. The situation of thread fracture is not conducive to the high uniformity and large deformation of the NPR spiral steel bar.

In summary, the steel bars in the prior art cannot meet the characteristics of high uniformity and large deformation of the NPR spiral steel bar, and cannot meet the good anchoring performance.

Utility model content

The embodiment of the utility model provides an NPR spiral steel bar to meet the characteristics of high uniformity and large deformation of the NPR spiral steel bar, and to meet good anchoring performance.

In order to achieve the above object, the present invention provides an NPR spiral steel bar, the outer surface of the NPR spiral steel bar is provided with a plurality of convex spiral ribs, and the spiral ribs have a spiral structure.

Further, the spiral ribs extend along the axial direction of the NPR spiral reinforcement.

Further, the number of the spiral ribs is 3-6.

Further, a plurality of the spiral ribs are evenly distributed along the circumferential direction of the NPR spiral reinforcement.

Further, the nominal diameter of the NPR spiral steel bar is 4mm-26mm.

Further, the width of the spiral rib is 1mm-4mm, and the lead of the spiral rib is 50mm-160mm.

The NPR spiral steel bar of the utility model can also enhance the binding force between the NPR spiral steel bar and the concrete under the condition that the NPR spiral steel bar has the characteristics of high uniformity and large deformation (elongation rate 20-60%), so that the NPR spiral steel bar is uniform In the case of large deformation, it has good anchoring performance.

Description of the drawings

Fig. 1 is a schematic diagram of the structure of the NPR spiral steel bar according to the first embodiment of the present invention;

2 is a schematic cross-sectional view of the NPR spiral steel bar in the first embodiment of the present invention;

Fig. 3 is a schematic cross-sectional view of the NPR spiral steel bar according to the second embodiment of the present invention.

detailed description

The following describes the utility model in further detail with reference to the accompanying drawings and specific embodiments, but it is not intended to limit the utility model.

Referring to Figures 1 and 2, the first embodiment of the present invention is shown. This embodiment provides an NPR spiral steel bar. The NPR spiral steel bar has a yield strength of 600-900MPa and a tensile strength of 900- 1100MPa, the maximum force elongation rate is 20-60%, and the structure of the NPR spiral steel bar of this material is improved. The outer surface of the NPR spiral steel bar 1 is provided with a plurality of convex spiral ribs 2, and the spiral ribs 2 are spiral状结构。 Like structure. In this embodiment, the number of spiral ribs is three.

The utility model has the advantages and positive effects that the spiral ribs 2 are continuously distributed on the outer surface of the NPR spiral steel bar, and the elongation during stretching is controllable, which can effectively meet the characteristic requirements of high uniformity and large deformation of the NPR spiral steel bar. The cross-sections of the NPR spiral steel bars are equal. The structure of the spiral rib 2 is more reasonable. There is no stress concentration in the diameter direction and no shear fracture. The spiral rib 2 can bond and bind to the concrete in the reinforced concrete project. Strengthen. When the reinforced concrete is under stress, the structure of the spiral rib 2 is more conducive to the occlusion between the concrete and the steel. It can also solve the problem of losing the anchoring force due to slippage, and improve the anchoring performance.

The NPR spiral steel bar of the utility model can also enhance the binding force between the NPR spiral steel bar and the concrete under the condition that the NPR spiral steel bar has the characteristics of high uniformity and large deformation (elongation rate 20-60%), so that the NPR spiral steel bar is uniform In the case of large deformation, it has good anchoring performance.

Preferably, the spiral ribs extend along the axial direction of the NPR spiral reinforcement. A number of spiral ribs are evenly distributed along the circumferential direction of the NPR spiral reinforcement.

As shown in Figure 1 and Figure 2, the nominal diameter of NPR spiral reinforcement is 4mm-26mm. The width d of the spiral rib is 1mm-4mm, and the lead L of the spiral rib is 50mm-160mm. The width d of the spiral rib is the size and width of the single rib of the spiral rib.

Refer to Figure 3, which shows a second embodiment of the present invention. This embodiment provides an NPR spiral steel bar. The outer surface of the NPR spiral steel bar 1 is provided with a plurality of convex spiral ribs. Spiral structure. In this embodiment, the number of spiral ribs is three. In other unshown embodiments, the number of spiral ribs can also be 4 or 5.

The NPR spiral steel bar of the utility model can also enhance the binding force between the NPR spiral steel bar and the concrete under the condition that the NPR spiral steel bar has the characteristics of high uniformity and large deformation (elongation rate 20-60%), so that the NPR spiral steel bar is uniform In the case of large deformation, it has good anchoring performance.

It should be noted that the terms used here are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprising" and/or "including" are used in this specification, they indicate There are features, steps, works, devices, components, and/or combinations thereof.

Of course, the above are the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the basic principles of the utility model, several improvements and modifications can be made, and these improvements and modifications are also regarded as the protection scope of the utility model.

Claims (6)

1. An NPR spiral steel bar is characterized in that the outer surface of the NPR spiral steel bar is provided with a plurality of convex spiral ribs, and the spiral ribs have a spiral structure.
2. The NPR spiral reinforcement according to claim 1, wherein the spiral ribs extend along the axial direction of the NPR spiral reinforcement.
3. The NPR spiral steel bar according to claim 1, wherein the number of the spiral ribs is 3-6.
4. The NPR spiral reinforcement according to claim 1, wherein a plurality of the spiral ribs are evenly distributed along the circumferential direction of the NPR spiral reinforcement.
5. The NPR spiral steel bar according to claim 1, wherein the nominal diameter of the NPR spiral steel bar is 4mm-26mm.
6. The NPR spiral steel bar according to claim 1, wherein the width of the spiral rib is 1mm-4mm, and the lead of the spiral rib is 50mm-160mm.

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