Pre-enclosed pressure ring-encircled steel strand-restrained concrete device and construction method

Abstract

The present application relates to a steel strand constrained concrete device technical field, specifically to a pre-surrounding pressure around steel strand constrained concrete device and construction method, including concrete column, the outside of concrete column is spirally wound with steel strand, the upper and lower ends of concrete column are fixedly connected with the clamp; The clamp is equipped with locking block, the locking block is equipped with locking block perforation for steel strand to pass through, the steel strand passes through the locking block perforation on both ends of two clamps and is connected with prestressed anchor, the prestressed anchor is fixedly connected with the locking block; Through the cooperation of steel strand, clamp, pull-out tester and prestressed anchor, continuous and uniform hoop confining pressure can be formed on the concrete column, the restraint effect on the concrete column is better, and the confining pressure is more convenient and efficient to apply, and the pull-out tester provides concentrated and controllable power source.

Description

Technical Field

[0001] This invention relates to the technical field of steel strand confined concrete devices, specifically a pre-compression surrounding steel strand confined concrete device and its construction method. Background Technology

[0002] In this era of rapid development, the number of buildings is constantly increasing, resulting in a wide variety of architectural structures. Concrete columns are the main load-bearing components in buildings, with diverse structural forms and complex stress performance. Through a series of studies, scholars have found that plain concrete columns have limited load-bearing capacity, while the structural form of confined concrete columns can effectively improve the stress performance of plain concrete columns, enhance the specimen's ability to resist external loads, and make the specimens more reliable and safe.

[0003] Concrete-filled steel tubular columns are columnar structures formed by pouring concrete into columnar molds. To address the poor load-bearing capacity of plain concrete columns and meet the load-bearing requirements of buildings, scholars have conducted research on the stress performance of confined concrete columns in various ways, such as using reinforcing bars, steel pipes, angle steel, FRP and other confining materials, or applying prestress to the confining materials.

[0004] Patent application number 201811248834.9 discloses an externally prestressed confined steel tube concrete column and its processing method. The technical problem it aims to solve is the "difficult and costly processing of small-diameter steel tube concrete". It uses steel tubes to confine the concrete and reinforces the connection between the steel tube and the concrete with steel strands. The disadvantages of this patent solution are: 1. The confinement of the concrete by the steel tube is a passive confinement. When the concrete column is subjected to external loads, the deformation of the concrete causes the deformation of the steel tube material, enabling the confinement material to play a confinement role, thereby delaying the development of concrete cracks and improving the stress performance of the concrete column. However, passive confinement has the problem of confinement stress lag and cannot suppress early concrete deformation. 2. The steel tube is subjected to stress in both the transverse and longitudinal directions, which easily leads to steel tube buckling. After the steel tube buckles, the confinement fails, and the steel strands also become ineffective.

[0005] Patent application number 201010152467.X discloses a tensioning and anchoring system for reinforcing concrete columns with prestressed steel strands, used for the reinforcement of general concrete columns. The technical problem it aims to solve is that "traditional reinforcement methods are complex to construct and cause structural damage." The key is to achieve non-destructive anchoring and prestress adjustment through bolt and nut assemblies. It emphasizes that "each steel strand is arranged parallel to the circumference of the concrete cylinder at equal intervals" to improve anchoring efficiency and load-bearing capacity. The disadvantages of this patented solution are: 1. This patented solution forms discrete linear constraint forces. This arrangement cannot generate uniform circumferential confining pressure on the concrete column because the force is distributed across multiple independent steel strands; 2. The bolt and nut system is a "push-pull" anchoring method, with prestress transmitted through steel plates, resulting in uneven force distribution and limitations imposed by bolt strength; multiple anchoring systems are required, increasing structural and construction complexity. Summary of the Invention

[0006] The main objective of this invention is to provide a pre-compression circumferential steel strand confined concrete device and construction method to solve the problems in the prior art where the steel strand confined concrete device cannot generate uniform circumferential compression on the concrete column, the confining force is unevenly distributed, the construction of the anchoring system is complicated due to the limitation of bolt strength.

[0007] To achieve the above objectives, the present invention provides a pre-containment compression device for confining concrete with steel strands, comprising a concrete column, on the outer side of which steel strands are spirally wound, and clamps fixedly connected to the upper and lower ends of the concrete column; the clamps are provided with locking blocks, and the locking blocks are provided with locking block through holes for the steel strands to pass through. The steel strands pass through the locking block through holes on the two clamps at both ends and are connected to prestressed anchors, and the prestressed anchors are fixedly connected to the locking blocks.

[0008] Furthermore, there are two steel strands, one of which is wound clockwise and the other is wound counterclockwise, with the two steel strands interlaced; locking blocks are symmetrically arranged on the left and right sides of the clamp.

[0009] Furthermore, there are multiple steel strands, some of which are wound clockwise and others are wound counterclockwise, with the multiple steel strands wound into a grid pattern.

[0010] Furthermore, the inner wall of the clamp is serrated, structural adhesive is bonded between the clamp and the concrete column, and the clamp is made of high-strength alloy steel.

[0011] Furthermore, an outer sleeve formed by grouting is installed on the outside of the concrete column.

[0012] Furthermore, the grouting material is a cement-based composite material with a compressive strength ≥60MPa and an expansion rate ≥0.02%.

[0013] The present invention also provides a construction method for a pre-confined steel strand confined concrete device, comprising the following steps: S1. Fix the clamps to the upper and lower ends of the concrete column; S2. Wind two steel strands, pass both ends of the steel strands through the locking block holes and connect them to the prestressed anchors; S3. Use a pull-out device to pull the two steel strands, apply circumferential pre-enclosing pressure to the concrete column, then remove the pull-out device and fix the steel strands with prestressed anchors. S4. Wrap the entire concrete column with a cylindrical mold, and fill the gap between the concrete column and the cylindrical mold with high-strength grout. The grout can fill the gap between the concrete column and the steel strand, ensuring that the confining pressure of the steel strand is completely transferred to the concrete column. After the grout has solidified, remove the cylindrical mold.

[0014] Furthermore, in step S4, the grouting material is a cement-based composite material with a compressive strength ≥60MPa and an expansion rate ≥0.02%.

[0015] The beneficial effects of this invention are: By combining steel strands, clamps, a pull-out device, and prestressed anchors, a continuous and uniform circumferential confining pressure can be formed on the concrete column, resulting in better constraint on the concrete column and making the application of confining pressure more convenient and efficient. The pull-out device provides a centralized and controllable force source. Each concrete column only requires two clamps to constrain the steel strands, making construction simpler and ensuring uniform distribution of confining pressure. The clamps are a simplified structure specifically designed for circumferential winding, making them more suitable for uniform pressure transmission.

[0016] By setting two steel strands to be wound in both directions, the confining pressure can be evenly distributed, avoiding local stress concentration; the locking blocks are symmetrically distributed on both sides of the clamp, which also makes the clamp more evenly stressed, making the connection between the clamp and the concrete column more stable, and reducing the risk of deformation caused by uneven stress on the clamp.

[0017] By setting up an outer sleeve formed by grouting material, and the grouting material being a cement-based composite material with a compressive strength ≥60MPa and an expansion rate ≥0.02%, the grouting material can fill the gap between the concrete column and the steel strand, ensuring that the confining pressure of the steel strand is completely transferred to the concrete; the synergistic effect of the steel strand and the concrete can increase the contact area between the two by 30% and increase the confining pressure effect by 50%. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1This is a schematic diagram of the pre-confined steel strand confined concrete device in Example 1; Figure 2 This is a schematic diagram of the clamp structure in Example 1; Figure 3 This is a schematic diagram of the prestressed anchorage in Example 1; Figure 4 This is a schematic diagram of the fixture in Example 1; Figure 5 This is a schematic diagram of the pre-confined steel strand confined concrete device in Example 3; Figure 6 This is a schematic diagram of the clamp structure in Example 3; Figure 7 This is a schematic diagram of the structure of the outer sleeve in Example 1.

[0020] In the diagram: 1. Concrete column; 2. Steel strand; 3. Clamp; 301. Locking block; 302. Locking block perforation; 4. Prestressed anchor; 401. Anchor sleeve; 402. Tapered hole; 403. Wedge; 404. Clamp perforation; 5. Outer sleeve; 6. Bolt. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] Example 1 like Figures 1 to 2 As shown, according to an embodiment of the present invention, a pre-confined steel strand confining concrete device is provided, comprising a concrete column 1; a steel strand 2 is spirally wound on the outer side of the concrete column 1, and clamps 3 are fixedly connected to the upper and lower ends of the concrete column 1; the clamps 3 include two half-clamps, and locking blocks 301 are provided at both ends of the half-clamps, and the two half-clamp shells are locked by bolts 6; the inner wall of the clamps 3 is serrated, and structural adhesive is bonded between the clamps 3 and the concrete column 1; the clamps 3 are made of high-strength alloy steel; the serrations and structural adhesive enhance the adhesion to the concrete and prevent slippage.

[0023] The locking block 301 is provided with a locking block through hole 302 for the steel strand 2 to pass through and a bolt hole for the bolt 6 to pass through. The steel strand 2 passes through the locking block through holes 302 on the two clamps at both ends and is connected to the prestressed anchor 4. The prestressed anchor 4 is fixedly welded to the locking block 301.

[0024] like Figure 3 and Figure 4As shown, the prestressed anchor 4 includes an anchor sleeve 401, in which a conical hole 402 is provided. At least two wedge-shaped clamps 403 are movably connected in the conical hole 402 to form a conical clamp. The clamp has a clamp through hole 404. The prestressed anchor has a self-locking function. The steel strand 2 passes through the clamp through hole 404 from the inside to the outside. The steel strand can only be pulled outward and cannot be retracted inward. This can tighten the steel strand 2 and apply a certain amount of prestress to the outside of the concrete column 1.

[0025] By combining steel strands, clamps, a pull-out device, and prestressed anchors, a continuous and uniform circumferential confining pressure can be formed on the concrete column, resulting in better constraint on the concrete column and making the application of confining pressure more convenient and efficient. The pull-out device provides a centralized and controllable force source. Each concrete column only requires two clamps to constrain the steel strands, making construction simpler and ensuring uniform distribution of confining pressure. The clamps are a simplified structure specifically designed for circumferential winding, making them more suitable for uniform pressure transmission.

[0026] Example 2 like Figure 7 As shown, Embodiment 2 also provides a pre-confined compression surrounding steel strand confined concrete device, which differs from the pre-confined compression surrounding steel strand confined concrete device in Embodiment 1 only in that: An outer sleeve 5 formed by grouting is provided on the outside of the concrete column 1; the grouting material is a cement-based composite material with a compressive strength ≥60MPa and an expansion rate ≥0.02%.

[0027] By setting up an outer sleeve formed by grouting material, and the grouting material being a cement-based composite material with a compressive strength ≥60MPa and an expansion rate ≥0.02%, the grouting material can fill the gap between the concrete column and the steel strand, ensuring that the confining pressure of the steel strand is completely transferred to the concrete; the synergistic effect of the steel strand and the concrete can increase the contact area between the two by 30% and increase the confining pressure effect by 50%.

[0028] Example 3 Example 3 also provides a pre-confined compression ring-wound steel strand confined concrete device, which differs from the pre-confined compression ring-wound steel strand confined concrete device in Example 2 only in that: like Figure 5 and Figure 6 As shown, there are two steel strands 2, one of which is wound clockwise and the other is wound counterclockwise, and the two steel strands 2 are intertwined; locking blocks 301 are symmetrically distributed on the left and right sides of the clamp 3.

[0029] By setting two steel strands to be wound in both directions, the confining pressure can be evenly distributed, avoiding local stress concentration; the locking blocks are symmetrically distributed on both sides of the clamp, which also makes the clamp more evenly stressed, making the connection between the clamp and the concrete column more stable, and reducing the risk of deformation caused by uneven stress on the clamp.

[0030] Example 4 Example 4 also provides a pre-confined compression ring-wound steel strand confined concrete device, which differs from the pre-confined compression ring-wound steel strand confined concrete device in Example 3 only in that: There are multiple steel strands 2, some of which are wound clockwise and others are wound counterclockwise, and the multiple steel strands 2 are wound into a grid; the grid-like constraint is more comprehensive.

[0031] Example 5 A construction method for a pre-confined steel strand-restrained concrete device according to Embodiment 2 includes the following steps: S1. Fix the clamp 3 to the upper and lower ends of the concrete column 1; S2. Winding steel strand 2, passing both ends of steel strand 2 through locking block through holes 302 and connecting them to prestressed anchors 4; S3. Use a puller to pull the steel strand 2, apply circumferential pre-coupling pressure to the concrete column 1, then remove the puller and fix the steel strand 2 with the prestressed anchor 4. S4. Use a cylindrical mold to enclose the entire concrete column 1. Fill the gap between the concrete column 1 and the cylindrical mold with high-strength grout. The grout can fill the gap between the concrete column 1 and the steel strand, ensuring that the confining pressure of the steel strand is completely transferred to the concrete column 1. After the grout has solidified, remove the cylindrical mold. The grout is a cement-based composite material with a compressive strength ≥60MPa and an expansion rate ≥0.02%.

[0032] Example 6 A construction method for a pre-confined steel strand-restrained concrete device according to Embodiment 3 includes the following steps: S1. Fix the clamp 3 to the upper and lower ends of the concrete column 1; S2. Wind two steel strands 2, pass both ends of the steel strands 2 through the locking block through hole 302 and connect them to the prestressed anchor 4; S3. Use a puller to pull the two steel strands 2, apply circumferential pre-coupling pressure to the concrete column 1, then remove the puller and fix the steel strands 2 with the prestressed anchor 4. S4. Use a cylindrical mold to enclose the entire concrete column 1. Fill the gap between the concrete column 1 and the cylindrical mold with high-strength grout. The grout can fill the gap between the concrete column 1 and the steel strand, ensuring that the confining pressure of the steel strand is completely transferred to the concrete column 1. After the grout has solidified, remove the cylindrical mold. The grout is a cement-based composite material with a compressive strength ≥60MPa and an expansion rate ≥0.02%.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A pre-confined, wrapped steel strand confined concrete device, comprising a concrete column (1); characterized in that, The outer side of the concrete column (1) is spirally wound with steel strand (2), and the upper and lower ends of the concrete column (1) are fixedly connected with clamps (3); the clamps (3) are provided with locking blocks (301), and the locking blocks (301) are provided with locking block through holes (302) for the steel strand (2) to pass through. The steel strand (2) passes through the locking block through holes (302) on the two clamps at both ends and is connected to a prestressed anchor (4). The prestressed anchor (4) is fixedly connected to the locking blocks (301).

2. The pre-confined steel strand confined concrete device as described in claim 1, characterized in that, The steel strand (2) is provided in two parts, one of which is wound clockwise and the other is wound counterclockwise, and the two steel strands (2) are wound in a cross manner; locking blocks (301) are symmetrically arranged on the left and right sides of the clamp (3).

3. The pre-confined steel strand confined concrete device as described in claim 1, characterized in that, The steel strands (2) are provided in multiple ways, with some of the steel strands wound clockwise and others wound counterclockwise, and the multiple steel strands (2) are wound into a grid.

4. The pre-confined steel strand confined concrete device as described in claim 1, characterized in that, The inner wall of the clamp (3) is serrated, and structural adhesive is bonded between the clamp (3) and the concrete column (1). The clamp (3) is made of high-strength alloy steel.

5. The pre-confined steel strand confined concrete device as described in claim 1, characterized in that, The outer side of the concrete column (1) is provided with an outer sleeve (5) formed by grouting.

6. The pre-confined steel strand confined concrete device as described in claim 5, characterized in that, The grouting material is a cement-based composite material with a compressive strength ≥60MPa and an expansion rate ≥0.02%.

7. A construction method for the pre-confined steel strand confined concrete device as described in claim 2, characterized in that, Includes the following steps: S1. Fix the clamp (3) to the upper and lower ends of the concrete column (1); S2. Wrap two steel strands (2), pass both ends of the steel strands (2) through the locking block through holes (302) and connect them to prestressed anchors (4); S3. Use a puller to pull the two steel strands (2), apply circumferential pre-enclosing pressure to the concrete column (1), then remove the puller and fix the steel strands (2) with the prestressed anchor (4). S4. Wrap the entire concrete column (1) with a cylindrical mold and fill the gap between the concrete column (1) and the cylindrical mold with high-strength grout. The grout can fill the gap between the concrete column (1) and the steel strand, ensuring that the confining pressure of the steel strand is completely transmitted to the concrete column (1). After the grout solidifies, remove the cylindrical mold.

8. The construction method as described in claim 7, characterized in that, In step S4, the grouting material is a cement-based composite material with a compressive strength ≥60MPa and an expansion rate ≥0.02%.

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