Outer wrapped concrete UHPC-stainless steel combined formwork air shaft structure and construction method

Abstract

The invention discloses an externally-wrapped concrete UHPC-stainless steel combined formwork air shaft structure and a construction method, the externally-wrapped concrete UHPC-stainless steel combined formwork air shaft structure comprises a UHPC-stainless steel combined formwork, staggered hole PBL shear keys, a reinforcement cage and external concrete, the UHPC-stainless steel combined formwork comprises a stainless steel cylinder and prefabricated UHPC, and the staggered hole PBL shear keys are arranged on the outer wall of the stainless steel cylinder. The performance advantages of a combined structure and an assembly type structure are combined, the rigidity and the bearing capacity of the UHPC-stainless steel combined formwork are enhanced, and the problems that a traditional stainless steel sheet is prone to deformation, bulging and protruding in the construction stage are effectively solved. Connection of the prefabricated UHPC, the stainless steel cylinder and external concrete is completed through the staggered hole PBL shear keys, the shear resistance between interfaces is improved, and cooperative work of all parts is guaranteed. The modular assembly type construction technology is adopted, the construction efficiency and the construction progress can be remarkably improved, the well wall thickness and the material consumption are reduced, and the method has remarkable performance advantages and wide application prospects in nuclear engineering structures.

Description

Technical Field

[0001] The invention belongs to the technical field of building structure design, and particularly relates to an outer-concrete UHPC-stainless steel combined formwork shell air shaft structure and a construction method. Background Art

[0002] The wind shaft structure is a special ventilation structure in nuclear chemical engineering, usually built with reinforced concrete. In special nuclear engineering structures in high-cold and high-corrosion environments, the inner wall surface of the wind shaft is often covered with stainless steel to ensure the corrosion resistance of the structure.

[0003] Since stainless steel is relatively expensive, in order to reduce the structural cost, thin stainless steel plates with smaller thickness are often used for pre-installation in engineering applications. However, during the concrete pouring construction phase, problems such as deformation, bulging and protrusions are prone to occur, resulting in construction quality that does not meet the requirements, uneven force, and reduced structural safety. Therefore, there is an urgent need to develop a wind shaft structure with excellent performance, convenient construction, and high economy. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide an outsourced concrete UHPC-stainless steel combined formwork air shaft structure and construction method, so as to solve the problems of easy deformation, bulging and protrusion of traditional stainless steel thin plates during the construction stage, and to improve the overall structural safety, improve construction efficiency and reduce comprehensive costs.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] An external concrete UHPC-stainless steel composite formwork air shaft structure, comprising a UHPC-stainless steel composite formwork, staggered PBL shear keys, a steel cage and external concrete;

[0007] The UHPC-stainless steel combined formwork includes a stainless steel cylinder and a prefabricated UHPC arranged outside the stainless steel cylinder; the staggered PBL shear key is arranged on the outer wall of the stainless steel cylinder, including a connecting component 1 embedded in the prefabricated UHPC and a connecting component 2 exposed from the prefabricated UHPC; the steel cage is arranged outside the staggered PBL shear key, and the external concrete is arranged outside the UHPC-stainless steel combined formwork.

[0008] In one embodiment, the prefabricated UHPC has a thickness of 20-50 mm and is made by direct injection or integral casting.

[0009] In one embodiment, the staggered PBL shear keys are arranged along the entire length of the wind shaft in the height direction and are arranged at equal intervals along the horizontal direction of the wind shaft.

[0010] In one embodiment, the connection component 1 and the connection component 2 have the same width, wherein the connection component 1 completes the connection between the stainless steel cylinder and the prefabricated UHPC, and the connection component 2 completes the connection between the prefabricated UHPC and the external concrete.

[0011] In one embodiment, the connecting component 1 and the connecting component 2 are both plate-shaped, one side of the connecting component 1 is welded to the outer wall of the stainless steel cylinder, and the other side is fixedly connected to the connecting component 2.

[0012] In one embodiment, the connection component 1 and the connection component 2 are respectively provided with reserved holes 1 and reserved holes 2 at equal intervals along the height direction, and the reserved holes 1 and reserved holes 2 are staggered in the horizontal direction.

[0013] In one embodiment, the steel cage includes horizontal steel bars, edge vertical steel bars, corner vertical steel bars and reinforced vertical steel bars arranged on both sides of the corner vertical steel bars; the horizontal steel bars are multiple rows of steel bars, and are staggered with the reserved holes 2 in the staggered PBL shear key along the height direction of the air shaft; the edge vertical steel bars are staggered with the staggered PBL shear key along the horizontal direction of the air shaft.

[0014] In one embodiment, the cast-in-place concrete is ordinary concrete, high-strength concrete, self-compacting concrete, recycled concrete or radiation-proof concrete.

[0015] The present invention also provides another design of the concrete-wrapped UHPC-stainless steel combined formwork air shaft structure, comprising a UHPC-stainless steel combined formwork, a PBL shear key, a steel cage and external concrete;

[0016] The UHPC-stainless steel combined formwork includes a stainless steel cylinder and a prefabricated UHPC arranged outside the stainless steel cylinder; the PBL shear key is arranged on the outer wall of the stainless steel cylinder throughout the length; the width of the PBL shear key is smaller than the thickness of the prefabricated UHPC, and reserved holes three are arranged at equal intervals along the height direction of the wind shaft, and the outer wall of the prefabricated UHPC is coated with roughening liquid; the steel cage is arranged outside the PBL shear key, and the external concrete is arranged outside the UHPC-stainless steel combined formwork.

[0017] The present invention also provides a construction method for the concrete-clad UHPC-stainless steel combined formwork air shaft structure, comprising:

[0018] Step 1, in the factory, welding staggered PBL shear keys or PBL shear keys on the outer wall of the stainless steel cylinder;

[0019] Step 2: In the factory, cast the prefabricated UHPC and complete the processing of the UHPC-stainless steel combined formwork; when welding the PBL shear key, apply roughening liquid on the outer wall of the prefabricated UHPC;

[0020] Step 3, on site, install the reinforcement cage and pour the exterior concrete.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) Convenient construction

[0023] The present invention has a simple structure, with staggered PBL shear keys welded on the stainless steel outer wall and UHPC cast, and a modular assembly construction technology of a stainless steel plate-UHPC combined formwork is adopted, which can significantly improve the construction efficiency and construction progress of the wind shaft, and a steel cage is placed on site and external concrete is cast, which greatly shortens the on-site construction period.

[0024] 2) Performance Improvement

[0025] The present invention adopts a prefabricated combined formwork, which can improve the rigidity and bearing capacity of the formwork, and effectively solve the problems of easy deformation, bulging and protrusion of traditional stainless steel thin plates during the construction stage. The staggered PBL shear keys respectively complete the connection between the prefabricated UHPC and the stainless steel cylinder and the external concrete, improve the shear resistance between the interfaces, ensure the coordinated work of various components, and ensure the safety of the overall structure.

[0026] 3) Economic benefits

[0027] Based on the wind shaft structure of the present invention, modular design and construction of the wind shaft can be achieved through reasonable optimization, reducing the thickness of the shaft wall and material consumption, reducing material costs, reducing subsequent maintenance costs, realizing the needs and advantages of differentiated material use, and comprehensively considering construction costs and shortening of construction period, with good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the construction of the outer concrete UHPC-stainless steel combined formwork air shaft structure of Example 1 of the present invention.

[0029] Figure 2 It is a cross-sectional schematic diagram of the outsourced concrete UHPC-stainless steel combined formwork air shaft structure of Example 1 of the present invention.

[0030] Figure 3 Schematic diagram of the structure of the UHPC-stainless steel combined formwork of Example 1 of the present invention.

[0031] Figure 4 It is a schematic diagram of the structure of the staggered hole PBL shear key of Example 1 of the present invention.

[0032] Figure 5 It is an overall schematic diagram of the steel cage of the present invention.

[0033] Figure 6 It is a schematic diagram of the structure of the UHPC-stainless steel combined formwork of Example 2 of the present invention.

[0034] Icons: 1-UHPC-stainless steel combined formwork; 2-staggered PBL shear key; 3-rebar cage; 4-cast-in-place concrete; 5-stainless steel cylinder; 6-prefabricated UHPC; 7-connection component one; 8-connection component two; 9-reserved hole one; 10-reserved hole two; 11-horizontal steel bars; 12-edge vertical steel bars; 13-corner vertical steel bars; 14-reinforced vertical steel bars; 15-PBL shear key; 16-reserved hole three. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0038] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the product is usually placed when in use. These are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0039] Example 1

[0040] like Figures 1 to 5 As shown, this embodiment provides a first form of a concrete-wrapped UHPC-stainless steel combined formwork air shaft structure, which mainly includes a UHPC-stainless steel combined formwork 1, a staggered PBL shear key 2, a steel cage 3 and external concrete 4.

[0041] Among them, reference Figure 1 , Figure 2 and Figure 3The UHPC-stainless steel combined formwork 1 includes a stainless steel cylinder 5 and a prefabricated UHPC 6. The stainless steel cylinder 5 is the central part of the equipment and is arranged along the height direction of the wind shaft. The cross-sectional shape and cross-sectional area of ​​the stainless steel cylinder 5 are designed and selected according to the requirements.

[0042] Prefabricated UHPC6 is arranged outside the stainless steel cylinder 5. Its thickness is designed and selected according to the demand, and the typical range is 20-50mm. It can be made by direct injection or integral casting. By arranging prefabricated UHPC6 outside the stainless steel cylinder 5, it is possible to reduce the wall thickness while ensuring or even improving the rigidity and bearing capacity of the formwork, effectively solving the problem of easy deformation, bulging and protrusion of traditional stainless steel thin plates during the construction stage.

[0043] The staggered hole PBL shear key 2 refers to at least two rows of holes arranged in the height direction, and the two rows of holes are staggered in the horizontal direction to form a staggered hole structure. Along the height direction of the wind shaft, the staggered hole PBL shear key 2 is arranged on the outer wall of the stainless steel cylinder 5 through the length, and can be specifically welded on the stainless steel cylinder 5 to improve the shear resistance between the interface of the stainless steel cylinder 5, UHPC6 and the external concrete 4. As a result, the thickness of the entire shaft wall can be significantly reduced, and materials, especially steel, can be saved. A portion of the staggered hole PBL shear key 2 is buried in the prefabricated UHPC6, and the other portion is exposed from the prefabricated UHPC6, and the buried portion and the exposed portion each have at least one row of holes. There are multiple staggered hole PBL shear keys 2 in this embodiment, which are arranged at equal intervals along the horizontal direction of the wind shaft.

[0044] Figure 4 A structural form of the staggered hole PBL shear key 2 of the present invention is shown, which includes a connection component 1 7 embedded in the prefabricated UHPC 6 and a connection component 2 8 exposed from the prefabricated UHPC. The direction perpendicular to the connection wall of the staggered hole PBL shear key 2 is defined as the width direction. In this embodiment, the width of the connection component 1 7 and the connection component 2 8 are preferably the same, wherein one side of the connection component 1 7 is welded to the outer wall of the stainless steel cylinder 5, and the other side is fixedly connected to the connection component 2 8 to complete the connection between the stainless steel cylinder 5 and the prefabricated UHPC 6. One side of the connection component 2 8 is fixedly connected to the other side of the connection component 1 7, and the other side is suspended to complete the connection between the prefabricated UHPC 6 and the external concrete 4. Through the connection between the connection component 1 7 and the connection component 2 8, the coordinated work of each component is ensured.

[0045] Furthermore, the connection component 1 7 and the connection component 2 8 of this embodiment are preferably plate-shaped, and along the height direction, a row of equally spaced reserved holes 1 9 is opened on the connection component 1 7, and a row of equally spaced reserved holes 10 is opened on the connection component 2 8. The reserved holes 1 9 and the reserved holes 2 10 are staggered in the horizontal direction to form a "staggered hole" structure of the staggered hole PBL shear key 2. The connection component 1 7 and the connection component 2 8 can be integrally formed during processing, or can be separately processed and then welded into one.

[0046] The connection part 1 7 in the staggered hole PBL shear key 2 is used to complete the interface connection between the stainless steel cylinder 5 and the prefabricated UHPC 6, and the connection part 2 8 is used to complete the interface connection between the prefabricated UHPC 6 and the external concrete 4. The staggered hole design avoids the stress concentration problem between adjacent reserved holes, makes the stress distribution relatively uniform, effectively transmits the shear force of different interfaces, and improves the integrity and service life of the structure.

[0047] In this embodiment, the steel cage 3 is arranged outside the staggered PBL shear key 2. Figure 5 A structural form of the steel cage 3 of the present invention is shown. It mainly includes horizontal steel bars 11, edge vertical steel bars 12, corner vertical steel bars 13 and reinforced vertical steel bars 14. The horizontal steel bars 11 are multiple rows of steel bars, which are evenly arranged on the periphery of the UHPC-stainless steel composite formwork 1 along the height direction of the wind shaft, and are located outside the staggered PBL shear key 2, and are staggered with the reserved holes 10 in the staggered PBL shear key 2. There are multiple edge vertical steel bars 12, which are arranged along the height direction of the wind shaft, and are arranged in the horizontal direction on the periphery of the UHPC-stainless steel composite formwork 1, staggered with the staggered PBL shear key 2. Here, the horizontal steel bars 11 and the edge vertical steel bars 12 are staggered with the staggered PBL shear key 2, which helps to control the development of cracks and make the structure more evenly stressed, thereby improving the integrity and durability of the structure.

[0048] There are multiple vertical corner steel bars 13, which are arranged along the height direction of the wind shaft and arranged at the outer corners of the UHPC-stainless steel composite formwork 1 in the horizontal direction. There are multiple vertical reinforcing steel bars 14, which are arranged along the height direction of the wind shaft and arranged on both sides of the vertical corner steel bars 13 in the horizontal direction. By arranging the vertical corner steel bars 13 and the reinforcing vertical steel bars 14 at the corners, the tensile cracking of the concrete at the corners can be prevented, thereby improving the durability of the wind shaft, while strengthening the restraint effect on the concrete, and improving the overall stability and bearing capacity of the structure.

[0049] The external concrete 4 is arranged outside the UHPC-stainless steel combined formwork 1, and can be ordinary concrete, high-strength concrete, self-compacting concrete, recycled concrete or radiation-proof concrete. It is cast on site and completely covers the steel cage 3 and the staggered PBL shear key 2.

[0050] Example 2

[0051] This embodiment provides a construction method for the outer concrete UHPC-stainless steel combined formwork air shaft structure of embodiment 1, and the main steps are as follows

[0052] Step 1: In the factory, the staggered PBL shear key 2 is welded on the outer wall of the stainless steel cylinder 5.

[0053] Step 2, in the factory, cast the prefabricated UHPC 6 on the outer wall of the stainless steel cylinder 5, cast the connection component 1 7 of the staggered PBL shear key 2 inside the prefabricated UHPC 6, and expose the connection component 2 8, completing the processing of the UHPC-stainless steel combined formwork 1.

[0054] Step 3, on site, install the steel cage 3, pour the external concrete 4, and pour the steel cage 3 and the second connecting component 8 inside.

[0055] It can be seen that in the construction process of this embodiment, the main components are processed in the factory, and only the steel bars need to be tied and concrete poured on site. This prefabricated construction technology can greatly improve the construction efficiency and progress.

[0056] Example 3

[0057] refer to Figure 6 As shown, this embodiment provides a first form of a concrete-wrapped UHPC-stainless steel combined formwork air shaft structure, which mainly includes a UHPC-stainless steel combined formwork 1, a PBL shear key 15, a steel cage 3 and external concrete 4.

[0058] Compared with Example 1, the present embodiment replaces the staggered PBL shear key 2 with a PBL shear key 15, and arranges a plurality of PBL shear keys 15 along the outer wall of the stainless steel tube 5, with the horizontal spacing of each PBL shear key 15 being equal. The width of the PBL shear key 15 is less than the thickness of the prefabricated UHPC 6, so that it can be completely cast in the prefabricated UHPC 6. The PBL shear key 15 is provided with reserved holes 16 at equal intervals along the height direction of the wind shaft. The UHPC tenons in the reserved holes 16 and the perforated steel plate jointly resist the shear force, thereby significantly improving the shear bearing capacity and enhancing the shear resistance and integrity of the interface connection between the prefabricated UHPC 6 and the stainless steel tube 5.

[0059] In this embodiment, since the PBL shear key 15 is cast in the precast UHPC 6, a roughening liquid is coated on the outer wall of the precast UHPC 6 to improve the roughness of the surface of the precast UHPC 6, improve the bonding force between the precast UHPC 6 and the external concrete 4, and enhance the integrity and durability of the interface connection between the precast UHPC 6 and the external concrete 4.

[0060] Compared with Example 1, this embodiment provides another interface connection method, using PBL shear key 15 and roughening liquid to complete the interface connection between UHPC 6 and stainless steel cylinder 5 and external concrete 4 respectively, which can greatly reduce the amount of steel used in the shear key and save material costs.

[0061] Example 4

[0062] This embodiment provides a construction method for the exterior concrete UHPC-stainless steel combined formwork air shaft structure of embodiment 3, and the main steps are as follows

[0063] Step 1: In the factory, a PBL shear key 15 is welded on the outer wall of the stainless steel cylinder 5 .

[0064] Step 2, in the factory, cast the prefabricated UHPC 6 on the outer wall of the stainless steel cylinder 5, cast the PBL shear key 15 inside the prefabricated UHPC 6, and apply roughening liquid on the outer wall of the prefabricated UHPC 6 to complete the processing of the UHPC-stainless steel combined formwork 1.

[0065] Step 3, on site, install the steel cage 3, pour the external concrete 4, and pour the steel cage 3 and the second connecting component 8 inside.

[0066] In summary, the present invention combines the performance advantages of the combined structure and the prefabricated structure, and proposes a UHPC-stainless steel combined formwork to enhance its rigidity and bearing capacity, effectively solving the problem of easy deformation, bulging and protrusion of traditional stainless steel thin plates during the construction stage. In Example 1, staggered PBL shear keys are used to respectively complete the connection between the prefabricated UHPC and the stainless steel cylinder and the external concrete, thereby improving the shear resistance between the interfaces and ensuring the coordinated work of various components. The present invention adopts modular prefabricated construction technology, which can significantly improve construction efficiency and construction progress, reduce the thickness of the well wall and the amount of materials used, and has significant performance advantages and broad application prospects in nuclear engineering structures.

Claims

1. A concrete UHPC-stainless steel combined formwork air shaft structure, characterized in that: It includes a UHPC-stainless steel composite formwork (1), a staggered PBL shear key (2), a steel cage (3) and external concrete (4); The UHPC-stainless steel combined formwork (1) comprises a stainless steel cylinder (5) and a prefabricated UHPC (6) arranged outside the stainless steel cylinder (5); the staggered PBL shear key (2) is arranged on the outer wall of the stainless steel cylinder (5), and comprises a first connection component (7) embedded in the prefabricated UHPC (6) and a second connection component (8) exposed from the prefabricated UHPC; the steel cage (3) is arranged outside the staggered PBL shear key (2), and the external concrete (4) is arranged outside the UHPC-stainless steel combined formwork (1).

2. According to claim 1, the concrete-clad UHPC-stainless steel combined formwork air shaft structure is characterized in that: The prefabricated UHPC (6) has a thickness of 20-50 mm and is manufactured by direct injection or integral casting.

3. According to claim 1, the concrete-clad UHPC-stainless steel combined formwork air shaft structure is characterized in that: The staggered PBL shear keys (2) are arranged along the entire length of the wind shaft in the height direction and are arranged at equal intervals in the horizontal direction of the wind shaft.

4. According to claim 1, the concrete-clad UHPC-stainless steel combined formwork air shaft structure is characterized in that: The connection component 1 (7) and the connection component 2 (8) have the same width, wherein the connection component 1 (7) completes the connection between the stainless steel cylinder (5) and the prefabricated UHPC (6), and the connection component 2 (8) completes the connection between the prefabricated UHPC (6) and the external concrete (4).

5. The concrete-clad UHPC-stainless steel combined formwork air shaft structure according to claim 1 or 4, characterized in that: The connecting component 1 (7) and the connecting component 2 (8) are both plate-shaped, one side of the connecting component 1 (7) is welded to the outer wall of the stainless steel cylinder (5), and the other side is fixedly connected to the connecting component 2 (8).

6. The concrete-clad UHPC-stainless steel combined formwork air shaft structure according to claim 5 is characterized in that: The connection component 1 (7) and the connection component 2 (8) are respectively provided with reserved holes 1 (9) and reserved holes 2 (10) at equal intervals in the height direction, and the reserved holes 1 (9) and reserved holes 2 (10) are staggered in the horizontal direction.

7. The concrete-clad UHPC-stainless steel combined formwork air shaft structure according to claim 6 is characterized in that: The steel cage (3) comprises horizontal steel bars (11), edge vertical steel bars (12), corner vertical steel bars (13), and reinforced vertical steel bars (14) arranged on both sides of the corner vertical steel bars (13); the horizontal steel bars (11) are multiple rows of steel bars, and are arranged in a staggered manner with the reserved holes (10) in the staggered PBL shear keys (2) along the height direction of the wind shaft; the edge vertical steel bars (12) are arranged in a staggered manner with the staggered PBL shear keys (2) along the horizontal direction of the wind shaft.

8. The concrete-clad UHPC-stainless steel combined formwork air shaft structure according to claim 1 is characterized in that: The cast-in-place concrete (4) is ordinary concrete, high-strength concrete, self-compacting concrete, recycled concrete or radiation-proof concrete.

9. A concrete UHPC-stainless steel combined formwork air shaft structure, characterized in that: It includes a UHPC-stainless steel composite formwork (1), a PBL shear key (15), a steel cage (3) and external concrete (4); The UHPC-stainless steel combined formwork (1) comprises a stainless steel cylinder (5) and a prefabricated UHPC (6) arranged outside the stainless steel cylinder (5); the PBL shear key (15) is arranged on the outer wall of the stainless steel cylinder (5) throughout the length; the width of the PBL shear key (15) is smaller than the thickness of the prefabricated UHPC (6), and reserved holes (16) are arranged at equal intervals along the height direction of the wind shaft; the outer wall of the prefabricated UHPC (6) is coated with roughening liquid; the steel cage (3) is arranged outside the PBL shear key (15), and the external concrete (4) is arranged outside the UHPC-stainless steel combined formwork (1).

10. The construction method of the concrete-wrapped UHPC-stainless steel combined formwork air shaft structure according to claim 1 or 9, characterized in that: include: Step 1, in the factory, welding a staggered PBL shear key (2) or a PBL shear key (15) on the outer wall of the stainless steel cylinder (5); Step 2, in the factory, casting the prefabricated UHPC (6) to complete the processing of the UHPC-stainless steel combined formwork (1); When welding the PBL shear key (15), a roughening liquid is applied to the outer wall of the prefabricated UHPC (6); Step 3, on site, install the steel cage (3) and pour the external concrete (4).

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