A precast wall panel using a steel mesh mold for forming holes

Abstract

This invention discloses a precast wall panel with holes formed using a steel mesh mold. The precast wall panel has vertically continuous holes formed during wall panel production using a non-removable steel mesh mold made of longitudinal or angle steel, steel mesh, and horizontal ribs. The longitudinal or angle steel in the steel mesh mold also serves as the vertical reinforcing steel of the wall. The precast wall panel does not have vertical reinforcing bars; additional connecting reinforcing bars are placed in the holes at the connection points between upper and lower wall panels, and concrete is poured into the holes to achieve lapped connections of the vertical reinforcing steel. The precast wall panel also has horizontal reinforcing bars, and adjacent wall panels on the same floor are connected by a post-cast section. The precast wall panel of this invention is convenient to produce and construct, and the connection structure has a reasonable stress distribution, solving the problems of production and construction difficulties and the inability to guarantee the force transmission performance of lapped connections that exist in traditional precast wall panels.

Description

Technical Field

[0001] This invention relates to the field of prefabricated components, and more particularly to prefabricated wall panels, specifically a type of prefabricated wall panel that forms through-holes by setting a steel mesh mold made of longitudinal ribs or angle steel, steel mesh and horizontal ribs welded together. Background Technology

[0002] Currently, in my country's prefabricated concrete structure system, prefabricated wall panels have different structures depending on the connection method used.

[0003] When vertical reinforcement bars are connected by sleeve grouting or grout-anchored lap joints, the wall panels are generally fully prefabricated, with grouting sleeves or corrugated pipes pre-embedded at the bottom. Prefabricated wall panels with this structure and connection method have reliable load-bearing performance, but on-site installation is more difficult, grouting quality is not easy to guarantee, and the cost is relatively high.

[0004] When vertical reinforcement is connected by post-cast concrete lap splices, the wall panels are generally partially precast, including double-sided composite precast wall panels with a hollow cavity layer in the middle and hollow precast wall panels with vertical holes. Double-sided composite precast wall panels are generally produced using a flip-plate process, which requires sophisticated equipment. Hollow precast wall panels are generally produced using a core-pulling or removable inner mold process, which also requires sophisticated equipment and processes and is not suitable for flat mold production. Production is also inconvenient for wall panels with diverse shapes and sizes. Furthermore, a common feature of the above-mentioned post-cast concrete lap splices is the presence of a precast and cast-in-place concrete interface between the vertical reinforcement within the wall panel and the additional connecting reinforcement in the cavity or holes, which is detrimental to the transfer of force during the lap splice.

[0005] In summary, to address the production process and lap joint force transmission issues inherent in traditional hollow precast wall panels, it is necessary to propose a new type of precast wall panel. This new type of precast wall panel would allow for greater freedom and flexibility in production, free from limitations imposed by equipment, site, shape, or size. Furthermore, it would ensure more direct and reliable force transmission through vertical steel reinforcement lap joints, thus providing technical support for the development of prefabricated concrete structure technology in my country. Summary of the Invention

[0006] The purpose of this invention is to provide a novel precast wall panel with vertically continuous openings. During production, the continuous openings are formed using a non-removable steel mesh mold, constructed from longitudinal or angle steel, steel mesh, and horizontal ribs. The longitudinal or angle steel in the steel mesh mold also serves as the vertical reinforcing steel of the wall. The precast wall panel does not have vertical reinforcing bars; additional connecting reinforcing bars are placed in the openings at the junctions of upper and lower wall panels, and concrete is poured into the openings to achieve lapped connections of the vertical reinforcing steel. The precast wall panel also has horizontal reinforcing bars, and adjacent wall panels on the same floor are connected by post-cast sections.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention proposes a precast wall panel using steel mesh molds for forming holes. Its features include several steel mesh molds spaced at intervals along the horizontal direction of the wall body, vertical structural reinforcement bars, horizontal reinforcement bars spaced at intervals along the vertical direction of the wall body, structural tie bars for connecting the vertical and horizontal reinforcement bars, and concrete located outside each steel mesh mold and cast in the factory. Each steel mesh mold forms a vertically continuous hole within the wall body, and the precast wall panel ensures that each steel mesh mold forms a complete, continuous cavity during production. Except for the horizontal reinforcement bars extending out of the wall body, all other components are located within the wall body.

[0009] The steel mesh mold includes a first steel mesh mold and a second steel mesh mold. The plane of each steel mesh mold is rectangular. The first steel mesh mold is a closed cavity with open top and bottom formed by welding four corner longitudinal bars that also serve as wall longitudinal bars and four steel meshes. The second steel mesh mold is a closed cavity with open top and bottom formed by welding four corner thin-walled angle steels that also serve as wall longitudinal bars and four steel meshes. The four corner longitudinal bars or corner thin-walled angle steels are all placed inside the steel mesh, and several horizontal keels are fixed on the outside of the steel mesh at equal intervals along the vertical direction.

[0010] Furthermore, when the precast wall panel has an opening, two first steel mesh molds are respectively spaced apart within the edge members on both sides of the opening. Each first steel mesh mold forms a vertical through hole within the edge member. The corner longitudinal bars in the first steel mesh mold also serve as longitudinal bars within the edge member. Vertical structural steel bars and tie bars are also provided outside the first steel mesh molds within the edge member on both sides of the opening.

[0011] Furthermore, when connecting the upper and lower precast wall panels, vertical connecting bars are provided between the vertical through holes in the upper and lower precast wall panels. The vertical connecting bars form an lap relationship with the corner longitudinal bars or angle steel of the steel mesh mold in the upper and lower precast wall panels. The length of the vertical connecting bars inserted into the through holes in the lower and upper precast wall panels should meet the requirements for lap force transmission.

[0012] Furthermore, when connecting precast wall panels on the same floor, a post-cast section is provided within the range of the horizontal reinforcing bars extending beyond the two adjacent precast wall panels on the same floor. Horizontal connecting reinforcing bars and vertical reinforcing bars are provided in this post-cast section.

[0013] The present invention has the following advantages:

[0014] 1) It avoids complex operations such as on-site grouting, making installation and construction convenient;

[0015] 2) Hole forming is convenient, without the need for core pulling, demolding and other processes;

[0016] 3) It facilitates flat mold production, has no special requirements for site, equipment, wall panel type and size, and is highly adaptable;

[0017] 4) The connecting steel bars and the wall panel steel bars overlap in the hole, making the force transmission more direct and reliable. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a precast wall panel (excluding openings) formed by using a steel mesh mold in Embodiment 1 of the present invention.

[0019] Figure 2 for Figure 1 A schematic diagram of section AA in the diagram.

[0020] Figure 3 This is a schematic diagram of the steel mesh mold 1 set in an embodiment of the present invention.

[0021] Figure 4 (a) and (b) are respectively Figure 3 Schematic diagrams of cross-sections at locations with and without horizontal keels.

[0022] Figure 5 This is a schematic diagram of the steel mesh mold 2 provided in an embodiment of the present invention.

[0023] Figure 6 (a) and (b) are respectively Figure 5 Schematic diagrams of cross-sections at locations with and without horizontal keels.

[0024] Figure 7 (a) and (b) are schematic diagrams of the vertical and horizontal connection structures of the prefabricated wall panels of the present invention, respectively.

[0025] Figure 8 This is a schematic diagram of a precast wall panel (including openings) using a steel mesh mold to form holes, according to Embodiment 2 of the present invention.

[0026] Figure 9 for Figure 8 A schematic diagram of section AA in the diagram. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of this invention.

[0028] To better understand this invention, the following details an application example of a precast wall panel using a steel mesh mold for forming holes, as proposed in this invention.

[0029] This invention provides a precast wall panel with holes formed using a steel mesh mold. The precast wall panel has vertically continuous holes formed by a non-removable steel mesh mold, constructed during wall panel production and made of longitudinal or angle steel, steel mesh, and horizontal reinforcing bars. The longitudinal or angle steel in the steel mesh mold also serves as vertical reinforcing steel for the wall structure. This hole-forming method is applicable to both precast interior wall panels and the inner leaf walls of precast sandwich insulated exterior wall panels. Specifically, a vertically continuous steel mesh mold is set during precast wall panel production. In addition, vertical structural reinforcing bars, horizontal reinforcing bars, and tie bars are provided. For wall panels with openings, longitudinal reinforcing bars and stirrups are also required within the area above and below the opening.

[0030] Example 1

[0031] See Figure 1 , Figure 2 This is a schematic diagram of a precast wall panel with holes formed by steel mesh molds according to Embodiment 1 of the present invention. The precast wall panel does not have any openings. The precast wall panel includes a plurality of steel mesh molds 1 or 2 spaced apart (generally at equal intervals) along the horizontal direction of the wall and vertical structural steel bars 3, horizontal steel bars 4 spaced apart along the vertical direction of the wall, structural tie bars 5 for connecting the vertical structural steel bars 3 and the horizontal steel bars 4, and concrete 6 located outside each steel mesh mold and poured in the factory. Except for the horizontal steel bars 4 extending out of the wall, the other components are all located inside the wall. Each steel mesh mold 1 or steel mesh mold 2 forms a vertical through hole 7 inside the wall.

[0032] See Figure 3 , Figure 4 The steel mesh mold 1 has a rectangular planar shape. It consists of four corner longitudinal ribs 11 and four steel meshes 12 welded together to form a closed cavity with open top and bottom. The steel mesh 12 can be made of expanded metal mesh or wire mesh. The four corner longitudinal ribs 11 are placed inside the steel mesh. Horizontal ribs 13 are evenly spaced vertically on the outer side of the steel mesh 12. These horizontal ribs 13 can be made of reinforcing steel or thin-walled steel and are welded to the steel mesh 12. The distance from the ends and sides of the steel mesh mold 1 to the surface of the precast wall panel is not less than 35mm and not more than 50mm. The length of the steel mesh mold 1 along the wall is not less than 150mm and not more than 250mm. The aperture size in the expanded metal mesh or wire mesh is not less than 3mm and not more than 5mm. The spacing of the horizontal ribs 13 should be determined according to the dimensions and rigidity requirements of the steel mesh mold 1, generally not less than 100mm and not more than 300mm. The corner longitudinal bars in steel mesh mold 1 also serve as wall longitudinal bars, and must meet the requirements for the cross-sectional area and bearing capacity of the wall longitudinal bars.

[0033] See Figure 5 , Figure 6 The steel mesh mold 2 uses four corner thin-walled angle steels 21 to replace the four corner longitudinal reinforcements 11 in the steel mesh mold 1, and the rest of the structure is the same as the steel mesh mold 1. The angle steels 21 should be cold-formed thin-walled angle steels, and the size of the angle steels should be determined according to the cross-section and bearing capacity of the angle steels that also serve as longitudinal reinforcements of the wall, with a side length of not less than 25mm and not more than 50mm.

[0034] The horizontal reinforcing bars 4 installed in the precast wall panel should meet the stress and structural requirements of the shear wall; the diameter of the vertical structural reinforcing bars 3 and structural tie bars 5 should not exceed 8mm, and the spacing of the structural tie bars 5 should be 400-600mm.

[0035] During the production of precast wall panels, only the portion outside the steel mesh mold 1 or 2 is poured to ensure that the concrete 6 does not flow into the steel mesh mold 1 or 2, so that a complete and continuous cavity is formed inside the steel mesh mold 1 or 2, which serves as the vertical continuous hole 7 of the precast wall panel.

[0036] See Figure 7 This is the connection structure for the precast wall panels. No vertical reinforcement is provided in the precast wall panels. Before pouring concrete into the vertically continuous opening 7 in the lower precast wall panel 01, vertical connecting reinforcement 03 should be installed between the upper precast wall panel 02 and the lower precast wall panel 01. This vertical connecting reinforcement 03 should lap with the corner longitudinal reinforcement or angle steel of the steel mesh in the lower precast wall panel 01 and the upper precast wall panel 02. During construction, the vertical connecting reinforcement 03 is inserted into the lower precast wall panel 01, and the insertion length meets the lap force transmission requirements. After the concrete pouring of the vertically continuous opening 7 in the lower precast wall panel 01 is completed and the floor slab 8 is constructed, the vertical connecting reinforcement 03 is protected. The exposed wall panels must meet the requirements for lap joint force transmission. Then, the upper precast wall panel 02 is installed, with connecting steel bars 03 inserted into the vertical through-hole of the upper precast wall panel 02 during installation. Finally, concrete is poured into the vertical through-hole of the upper precast wall panel 02 to connect the upper and lower precast wall panels. Furthermore, a joint 9 must be provided between the upper precast wall panel 02 and the top surface of the floor slab 8. High-strength grout should be laid at the joint 9 before the installation of the upper precast wall panel 02, or a gap should be pre-reserved so that the concrete flows in and fills the vertical through-hole after the installation of the precast wall panel 02. The precast wall panels have horizontal reinforcing bars, which can be in a closed ring shape. A post-cast section 04 is provided between adjacent wall panels on the same floor, containing horizontal connecting steel bars 05 and vertical steel bars 06. Concrete is poured into the post-cast section 04 to connect the adjacent wall panels.

[0037] Example 2

[0038] See Figure 8 , Figure 9 This is a schematic diagram of a precast wall panel with holes formed by a steel mesh mold according to Embodiment 2 of the present invention. The precast wall panel has openings 10 inside. The difference from Embodiment 1 is that in this embodiment, edge members 101 are provided on both sides of the openings 10. Figure 9Within the range of the thick dashed line, two steel mesh molds 1 are provided at intervals within each edge member 101. These two steel mesh molds 1 form vertical through-holes 102 in the edge members. The longitudinal bars in the steel mesh molds 1 also serve as longitudinal bars in the edge members, and must meet the requirements for the cross-sectional area and bearing capacity of the longitudinal bars in the edge members. At the same time, vertical structural steel bars 103 and tie bars 104 are also required to be provided outside the steel mesh molds within the range of each edge member 101. The diameter of the vertical structural steel bars 103 and tie bars 104 is not less than 8mm. The spacing of the tie bars 104 should be the same as that of the horizontal steel bars 4, and both should meet the minimum reinforcement quantity and spacing requirements of the stirrups in the edge members. The spacing is generally not less than 100mm and not more than 200mm. In addition, longitudinal bars and stirrups are also required to be provided above and below the opening. The longitudinal bars and stirrups must meet the stress requirements. In this embodiment, longitudinal bars 105 and 106 and stirrups 107 are provided in the upper part of the opening 10, which should meet the stress and structural requirements of the connecting beam. The construction of other wall sections outside the edge member range in this embodiment is the same as in Embodiment 1. The connection construction of the upper and lower wall panels in this embodiment is the same as in Embodiment 1.

[0039] In the description and accompanying drawings, the products and methods of the present invention are described in particular shapes, materials, or process sequences, and detailed parameters are provided for illustrative purposes for some specific embodiments. However, it should be understood that these specific descriptions do not limit the technical solutions of the present invention; that is, changes and modifications to the shapes, materials, or process sequences are still included within the spirit and scope of the present invention.

Claims

1. A precast wall panel using a steel mesh mold for forming holes, characterized in that, It includes several steel mesh molds and vertical structural steel bars spaced apart along the horizontal direction of the wall, horizontal steel bars spaced apart along the vertical direction of the wall, structural tie bars for connecting the vertical structural steel bars and horizontal steel bars, and concrete located outside each of the steel mesh molds and poured in the factory. Each steel mesh mold forms a vertical, continuous hole within the wall, and the precast wall panels are manufactured to ensure that each steel mesh mold forms a complete, continuous cavity. Except for the horizontal reinforcing bars that extend out of the wall, all other components are located inside the wall. The steel mesh mold includes a first steel mesh mold and a second steel mesh mold. The plane of each steel mesh mold is rectangular. The first steel mesh mold is a closed cavity with open top and bottom formed by welding four corner longitudinal bars that also serve as wall longitudinal bars and four steel meshes. The second steel mesh mold is a closed cavity with open top and bottom formed by welding four corner thin-walled angle steels that also serve as wall longitudinal bars and four steel meshes. The four corner longitudinal ribs or corner thin-walled angle steels are all placed inside the steel mesh, and several horizontal keels are fixed on the outside of the steel mesh at equal intervals along the vertical direction. When the precast wall panel has an opening, two first steel mesh molds are respectively spaced apart within the edge members on both sides of the opening. Each first steel mesh mold forms a vertical through hole within the edge member. The corner longitudinal ribs in the first steel mesh mold also serve as longitudinal ribs within the edge member. The outer side of the first steel mesh formwork within the edge components on both sides of the opening is also provided with a second vertical structural steel bar and a second structural tie bar; The diameter of the vertical structural reinforcement bars and structural tie bars shall not exceed 8mm; The spacing of the structural tie rods is 400-600 mm; The diameter of the second vertical structural reinforcement and the second structural tie bar is not less than 8mm. The spacing of the second structural tie bar is the same as that of the horizontal reinforcement, and the spacing is not less than 100mm and not more than 200mm. When connecting the upper and lower precast wall panels, vertical connecting bars are provided between the vertical through holes in the upper and lower precast wall panels. The vertical connecting bars form an lap relationship with the corner longitudinal bars or angle steel of the steel mesh mold in the lower and upper precast wall panels. The length of the vertical connecting bars inserted into the lower and upper precast wall panels meets the lap force transmission requirements. When connecting precast wall panels on the same floor, a post-cast section is set within the range of the horizontal reinforcing bars extending beyond the two adjacent precast wall panels on the same floor. Horizontal connecting reinforcing bars and vertical reinforcing bars are set in the post-cast section. The steel mesh is made of expanded metal mesh or steel wire mesh; The horizontal keel is made of steel bars or thin-walled steel, and the horizontal keel is welded and fixed to the steel mesh. The distance from the end and side of the steel mesh mold to the surface of the precast wall panel is not less than 35mm and not more than 50mm, and the dimension of the steel mesh mold along the length of the wall is not less than 150mm and not more than 250mm. The size of the holes in the steel mesh is not less than 3mm and not more than 5mm; The spacing between the horizontal keels shall be no less than 100mm and no more than 300mm; The side length of the thin-walled angle steel at the corner is not less than 25mm and not more than 50mm.

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