Laminated slab, laminated slab forming method and prefabricated composite rib for laminated slab

Abstract

The invention provides a laminated slab, a laminated slab forming method and a prefabricated composite rib for the laminated slab, and belongs to the field of fabricated constructions.The laminated slab comprises a prefabricated bottom plate and the prefabricated composite rib, and the prefabricated composite rib at least comprises a framework, a first concrete rib section and a second concrete rib section; the bottom of the framework is fixed to the prefabricated bottom plate in a buried mode, the first concrete rib section and the second concrete rib section are formed on the upper chord of the framework in a wrapping mode, a space is formed between the first concrete rib section and the prefabricated bottom plate, the bottom of the second concrete rib section and the prefabricated bottom plate form a continuous force transmission structure, and the continuous force transmission structure is located in a load concentration area of the laminated slab. The combined ribs are adopted, variable-rigidity ribs are achieved through the first concrete rib section and the second concrete rib section, force is directly transmitted between the second concrete rib section and the prefabricated bottom plate in a load concentration area (the maximum bending moment area) to meet the larger rigidity requirement, and the first concrete rib section is adopted in a load non-concentration area to save materials; and compared with a traditional concrete rib laminated slab, the rigidity of the whole laminated slab is improved by about 1.5 times.

Description

Technical Field

[0001] The invention belongs to the field of prefabricated buildings, and in particular relates to a composite board, a composite board forming method and a prefabricated composite rib for the composite board. Background Art

[0002] As an important component in the field of prefabricated buildings, concrete rib composite slabs mainly include concrete ribs and prefabricated base plates. The concrete ribs are used to strengthen the rigidity of the prefabricated base plates, which facilitates transportation and lifting and prevents cracking. Therefore, concrete rib composite slabs have been tried to be promoted due to their advantages such as good vertical rigidity, convenient construction and cost savings, and are widely used in floor slabs and floor structures.

[0003] However, during hoisting, transportation and installation, the bending moment of the composite slab is the largest in the middle and the smallest on both sides; the load is concentrated in the middle of the slab. Traditional composite slabs, whether truss ribs or concrete ribs, have a large stiffness requirement in the middle of the slab, which is difficult to meet during hoisting, transportation and installation, resulting in problems such as cracking of concrete ribs and deformation of truss ribs.

[0004] Furthermore, when laying out pipelines, concrete rib composite plates often choose to groove the ribs, which further undermines the structural strength, while truss rib composite plates are difficult to meet the stiffness requirements over large spans.

[0005] For this reason, the present invention arises as the times require.

[0006] It should be noted that the information disclosed in the background technology section of the invention is only intended to deepen the understanding of the general background technology of the invention, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0007] One object of the present invention is to provide a composite plate with variable stiffness that can meet the needs of uneven loads; The second object of the present invention is to provide a method for forming a composite plate with variable stiffness that can meet the needs of uneven loads; The third object of the present invention is to provide a prefabricated composite rib for a composite plate that can achieve variable stiffness and is applied in the structure of the composite plate.

[0008] To achieve at least one of the above purposes, the present invention first provides a composite board, comprising: Prefabricated base plate; Prefabricated composite ribs, where the prefabricated composite ribs at least include a framework, a first concrete rib section, and a second concrete rib section; the bottom of the framework is buried and fixed to the prefabricated bottom slab, the first concrete rib section is formed by wrapping around the upper chord of the framework, a space is formed between the first concrete rib section and the prefabricated bottom slab, the second concrete rib section is formed by wrapping around the upper chord of the framework, and the bottom of the second concrete rib section and the prefabricated bottom slab form a continuous force transmission structure, and the continuous force transmission structure is located in the load concentration area of the composite slab.

[0009] Preferably, the continuous force transmission structure is implemented as the second concrete rib section and the prefabricated bottom slab being integrally cast; alternatively, the second concrete rib section and the prefabricated bottom slab are in force transmission contact or connection.

[0010] Preferably, the prefabricated composite ribs further include a lower chord, the lower chord is connected to the web members of the framework, and forms a truss with the web members and the upper chord, and the lower chord is buried and fixed to the prefabricated bottom slab.

[0011] Preferably, a bearing bar is also provided between the ends of the lower chord and the ends of the upper chord.

[0012] Preferably, the position of the first concrete rib section corresponds to the non-load concentration area of the composite slab.

[0013] Preferably, the load concentration area is defined as the area with a larger mid-span moment of the composite slab; the non-load concentration area is defined as the area with a smaller side-span moment of the composite slab.

[0014] Preferably, the number of the first concrete rib sections is at least two, and one second concrete rib section is located between the two first concrete rib sections.

[0015] Preferably, a steel rib section is formed between the first concrete rib section of the prefabricated composite ribs and the edge of the prefabricated bottom slab, and the steel rib section is implemented as a wiring section for pipelines.

[0016] The technical effects produced by the above technical solutions of the present invention come from one or more of the following combinations: By adopting composite ribs, variable stiffness ribs are realized with the first concrete rib section and the second concrete rib section. In the load concentration area (the area with the largest moment), the second concrete rib section directly transmits force to the prefabricated bottom slab to meet the greater stiffness requirement. In the non-load concentration area, the first concrete rib section is used to save materials, so that the stiffness of the overall composite slab is increased by about 1.5 times compared with the traditional concrete rib composite slab.

[0017] The overall structure has a wider range of choices for precast floor slabs, and prestressed floor slabs, high-performance concrete floor slabs, ordinary concrete floor slabs, etc. can be selected. When a prestressed floor slab is selected, in the load concentration area (the area with the largest bending moment), the second concrete rib section is cast integrally with the precast floor slab or in force transmission contact, which can also prevent the precast floor slab from arching and can further reduce the thickness of the precast floor slab.

[0018] In the precast composite ribs, the steel structure can be a frame or a truss. When using a frame, the web members are fixed to the structural reinforcement of the precast floor slab. When using a truss, the lower chord is fixed to the structural reinforcement of the precast floor slab, which is simple and convenient.

[0019] For the variable stiffness precast composite ribs of this solution, the second concrete rib section in the 30% area in the middle span (with relatively large bending moment) can be precast and formed in the factory or formed integrally with the composite floor slab. In the 30% area of the two side spans (with relatively small bending moment), the first concrete rib section is precast in advance with UHPC ribs and jointly forms precast ribs with the truss reinforcement to achieve industrial production. In the 10% area at the end, it is directly a steel rib section of the truss reinforcement, which is convenient for passing through pipelines with a larger diameter.

[0020] The truss reinforcement uses steel bars with diameters of 6, 5, and 5 (mm); the upper chord reinforcement uses 6; the web members and the lower chord use 5. The bearing seat reinforcement is welded at the end to increase the stiffness contribution of the rib and achieve the continuity of the slab, turning the simply supported slab into a continuous slab.

[0021] In the middle span (with relatively large bending moment) part, a casting mesh plate (steel mesh) is used to precast the pouring space for the second concrete rib section, and it is directly sleeved on the precast composite ribs in the factory for construction to improve the on-site construction efficiency.

[0022] The present invention also provides a method for forming a composite slab, including: At least the upper chord of the frame is precast and coated at intervals to form the first concrete rib section to form precast composite ribs, and a forming space for the second concrete rib section is formed between at least two of the first concrete rib sections; The precast composite ribs are poured and formed into a composite slab in cooperation with the precast floor slab. At least the forming space for the second concrete rib section and the pouring space of the precast floor slab are integrally poured and formed to form the precast floor slab and the second concrete rib section. The second concrete rib section and the precast floor slab form a continuous force transmission structure, and the continuous force transmission structure is located in the load concentration area of the composite slab.

[0023] Preferably, at least a casting mesh plate is arranged at the bottom and side of the forming space for the second concrete rib section, and the forming space for the second concrete rib section is enclosed by the casting mesh plate.

[0024] The technical effects produced by the above technical solutions of the present invention come from one or more of the following combinations: This method integrally pours and forms the second concrete rib section and the precast bottom slab of the composite slab. By setting a pouring mesh plate to form a pouring formwork, the mesh holes connect the second concrete rib section and the precast bottom slab, further improving the structural stiffness and integrity.

[0025] The steel mesh is prefabricated and directly assembled at the factory for construction, improving the on-site construction efficiency; between the second concrete rib section and the precast bottom slab, a pouring mesh plate is used for enclosing and plugging to realize the simplified process of pouring the second concrete rib section at the mid-span.

[0026] The present invention also provides a method for forming a composite slab, including: At least pre-pour and cover the upper chord of the truss to form a first concrete rib section and a second concrete rib section to form a precast composite rib, and at least the second concrete rib section is located between the two first concrete rib sections; Pour and form the precast composite rib in cooperation with the precast bottom slab, and at least the bottom end of the second concrete rib section is in force transmission contact or connection with the precast bottom slab to form a continuous force transmission structure, and the continuous force transmission structure is located in the load concentration area of the composite slab.

[0027] The technical effects produced by the above technical solutions of the present invention: This method pre-pours and forms the second concrete rib section and the first concrete rib section, and then the precast composite rib can be placed as a whole on the pouring mold of the precast bottom slab, without formwork support for the second concrete rib section.

[0028] The present invention also provides a precast composite rib for a composite slab, which at least includes a truss, two first concrete rib sections and one second concrete rib section; the first concrete rib sections are covered and formed on the upper chord of the truss, the second concrete rib section is covered and formed on the upper chord of the truss and is located between the two first concrete rib sections, and the bottom of the second concrete rib section has a force transmission contact surface with the precast bottom slab of the composite slab, and the position of the force transmission contact surface corresponds to the load concentration area of the composite slab.

[0029] The technical effects produced by the above technical solutions of the present invention: The precast composite rib of the present invention can be prefabricated in large quantities in the factory, and the first concrete rib section and the second concrete rib section are pre-poured and formed, and then transported in batches to the composite slab factory for forming the composite slab. The process is simple and there is no need for secondary formwork support for the first concrete rib section and the second concrete rib section.

[0030] The present invention also provides a precast composite rib for a composite slab, which at least includes a truss and two first concrete rib sections; the first concrete rib sections are covered and formed on the upper chord of the truss, and a second concrete rib section forming space is formed between the two first concrete rib sections. The second concrete rib section forming space is integrally formed with the precast bottom slab of the composite slab to form a second concrete rib section, and the second concrete rib section and the precast bottom slab form a continuous force transmission structure, and the continuous force transmission structure is located in the load concentration area of the composite slab.

[0031] Technical effects produced by the above technical solutions of the present invention: The precast composite ribs of the present invention can be precast in large quantities in a factory. The first concrete rib section is precast and formed to reserve the forming space for the second concrete rib section. They are transported in batches to the composite slab factory for the forming of the composite slab. The second concrete rib section and the precast bottom slab are integrally cast, making the integrity better and the bearing capacity stronger. Description of the Drawings

[0032] Figure 1 It shows a schematic structural view of a composite slab.

[0033] Figure 2 It shows another schematic structural view of a composite slab.

[0034] Figure 3 It shows a front view of a composite slab.

[0035] Figure 4 It shows another front view of a composite slab.

[0036] Figure 5 It shows a front view after the precast composite ribs are formed.

[0037] Figure 6 It shows a schematic structural view after the precast composite ribs are formed.

[0038] Figure 7 It shows a position diagram of the forming space of the second concrete rib section in the precast composite ribs.

[0039] Figure 8 It shows a front view of the formwork support of the pouring mesh plate in the precast composite ribs.

[0040] Figure 9 It shows a three-dimensional view of the formwork support of the pouring mesh plate in the precast composite ribs.

[0041] Figure 10 It shows a schematic view of the forming of the second concrete rib section in the precast composite ribs.

[0042] Wherein: 1. Precast bottom slab; 2. Precast composite rib; 21. Truss; 211. Upper chord; 212. Web member; 213. Lower chord; 214. Support bar; 22. First concrete rib section; 23. Second concrete rib section; 230. Forming space of the second concrete rib section; 231. Pouring mesh plate; 2311. Side plate; 2312. End plate; 2313. Bottom plate; 24. Steel rib section. Detailed Implementation Manner

[0043] The following description is provided to enable a person skilled in the art to implement and use the present invention and incorporate it into a specific application context. Various variations and various uses in different applications will be readily apparent to a person skilled in the art, and the general principles defined herein can be applied to a wide range of embodiments. Thus, the present invention is not limited to the embodiments given herein, but should be accorded the broadest scope consistent with the principles and novel features disclosed herein.

[0044] In the following detailed description, numerous specific details are set forth to provide a more thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the practice of the present invention may not be limited to these specific details. In other words, well-known structures and devices are shown in block diagram form without detailed display to avoid obscuring the present invention.

[0045] The reader is directed to all documents and references that are filed concurrently with this specification and that are open to public inspection with this specification, and the contents of all such documents and references are incorporated herein by reference. Unless otherwise directly stated, all features disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent, or similar purpose. Thus, unless otherwise expressly stated, each feature disclosed is only an example of a group of equivalent or similar features.

[0046] Note that, where used, the labels left, right, front, rear, top, bottom, positive, negative, clockwise, and counterclockwise are used for convenience only and do not imply any specific fixed direction. In fact, they are used to reflect the relative positions and / or orientations between various parts of an object. Additionally, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" shall be construed broadly. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection; it may be a direct connection, or an indirect connection through an intermediate medium, and it may be the communication between two elements inside. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Note that, in cases where it is used, "furthermore", "preferably", "even further", and "more preferably" are simply the starting points for elaborating another embodiment based on the foregoing embodiments. The content following the "furthermore", "preferably", "even further", or "more preferably" in combination with the foregoing embodiments constitutes the complete composition of another embodiment. Combinations can be made arbitrarily among several "furthermore", "preferably", "even further", or "more preferably" settings following the same embodiment to form yet another embodiment.

[0049] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. Note that the aspects described below in conjunction with the accompanying drawings and specific embodiments are merely exemplary and should not be construed as imposing any limitation on the protection scope of the present invention.

[0050] Application Overview: The composite slab includes a precast bottom slab and a composite layer (cast-in-place layer). In the market, the widely promoted composite slabs are steel truss composite slabs and concrete rib composite slabs. As those skilled in the art should know, generally for the convenience of description, the precast bottom slab + steel truss; or the precast bottom slab + concrete rib, which is the factory precast part, is directly named as the composite slab because the core of this technical field generally lies in the technological iteration of the precast part. Therefore, in this application, the precast bottom slab and the precast composite rib are also named as the composite slab, and the cast-in-place composite layer is not described. Those skilled in the art should know.

[0051] Structural Embodiment 1: Please refer to Figures 1 to 10 , this embodiment provides a composite slab, including a precast bottom slab 1 and a precast composite rib 2. Among them, the precast composite rib 2 at least includes a framework, a first concrete rib section 22 and a second concrete rib section 23; the bottom of the framework is buried and fixed on the precast bottom slab 1, the first concrete rib section 22 is formed by covering the upper chord 211 of the framework, a space is formed between the first concrete rib section 22 and the precast bottom slab 1, the second concrete rib section 23 is formed by covering the upper chord 211 of the framework, and the bottom of the second concrete rib section 23 forms a continuous force transmission structure with the precast bottom slab 1, and the continuous force transmission structure is located in the load concentration area of the composite slab.

[0052] This embodiment does not uniquely limit the type of the precast bottom slab 1, and high-performance concrete slabs, prestressed concrete slabs, etc. can be selected.

[0053] As is well known, the bending moment in the mid-span region of the composite slab is the largest, while that in the two side regions is smaller. Therefore, the stiffness requirement is the largest at the mid-span position and gradually decreases towards the two side edges. Thus, in this embodiment, the load concentration region is defined as the region with a larger mid-span bending moment of the composite slab; the non-load concentration region is defined as the region with a smaller bending moment at the side edges of the composite slab. Specifically, during hoisting and installation, the load is larger in the 30% region at the mid-span (where the bending moment is larger), and the structural rib with large stiffness is strengthened through the continuous structure of the second concrete rib section 23 and the precast bottom slab 1; the load is smaller in the 30% region of the two side spans (where the bending moment is smaller), and the first concrete rib section 22 is precast in advance with UHPC ribs and jointly forms a precast rib with the truss 21 steel bars to achieve industrialized production.

[0054] The continuous force transmission structure between the second concrete rib section 23 and the precast bottom slab 1 is implemented such that they are in surface-to-surface contact for force transmission or they are directly integrally cast into a whole. That is, the continuous force transmission structure is implemented as the second concrete rib section 23 and the precast bottom slab 1 being integrally cast into a whole ( Figure 1 ); or, the second concrete rib section 23 and the precast bottom slab 1 are in force transmission contact or connection ( Figure 2 ).

[0055] When the second concrete rib section 23 and the precast bottom slab 1 are integrally cast into a whole, please refer to Figure 1 、 Figure 3 、 Figure 7 and Figure 8 and Figure 9 . Preferably, the first concrete rib section 22 is precast in the 30% region of the two side spans (where the bending moment is smaller), and a forming space 230 for the second concrete rib section is formed between the two first concrete rib sections 22. Further, pouring mesh plates 231 are arranged at the bottom and side of the forming space 230 for the second concrete rib section, and the forming space 230 for the second concrete rib section is enclosed by the pouring mesh plates 231.

[0056] Specifically, please refer to Figure 9 . The pouring mesh plate 231 at least includes a bottom plate 2313 and side plates 2311, and the two side plates 2311 are located on both sides of the upper chord 211. There is a space between the top surface of the first concrete rib section 22 and the precast bottom slab 1. As a preferred embodiment of this embodiment, end plates 2312 are also provided at this space for blocking. Thus, the pouring and forming space for the second concrete rib section 23 is formed together by the side plates 2311 on both sides, the bottom plate 2313 at the bottom, and the end plates 2312 at the ends. During the pouring process, the bottom plate 2313, the side plates 2311, and the end plates 2312 are all steel mesh plates. Their advantage is that it is convenient to avoid the position of the web members. When there is a position conflict, the web members can directly pass through the steel mesh plates, and at the same time, positioning and fixing can also be completed.

[0057] Furthermore, a steel rib section 24 is formed between the first concrete rib section 22 of the precast composite rib 2 and the edge of the precast bottom plate 1, and the steel rib section 24 is implemented as a routing section for pipelines. Preferably, in a total of 10% of the areas at both ends of the composite slab, the steel rib section 24 is directly the steel bar of the truss 21, which is convenient for routing pipelines with a larger diameter. It should be noted that the total of 10% of the areas at both ends of the composite slab is not the only limitation. Firstly, the regional parameters are not restricted, and secondly, its necessity is not restricted. When the space below the first concrete rib section 22 of the precast composite rib 2 can complete the routing, the steel rib section 24 can be replaced by the extension of the first concrete rib section 22 to form a structure in which the first concrete rib section 22 and the second concrete rib section 23 are of the same length as the span of the precast bottom plate 1.

[0058] Furthermore, the end of the first concrete rib section 22 facing the second concrete rib section 23 can be implemented as a vertical surface or a slope surface; the end of the second concrete rib section 23 is implemented as Figure 3 the slope surface shown, or is implemented as Figure 4 the vertical surface + slope surface shown, so as to prevent stress concentration with the change of the inclined surface.

[0059] As described above, the entire precast composite rib 2 is implemented as a variable stiffness composite rib of 5% steel rib section 24 + 30% first concrete rib section 22 + 30% second concrete rib section 23 + 30% first concrete rib section 22 + 5% steel rib section 24, which meets the anti-bending moment requirements of different areas of the composite slab. It should be noted that this is the preferred implementation mode of this embodiment and is not the only limitation. The proportion of each area also changes reasonably according to actual needs or span design.

[0060] When the second concrete rib section 23 is in force transmission contact with the precast bottom plate 1, as shown in Figure 2 and Figure 4 shown, at this time, the second concrete rib section 23 and the first concrete rib section 22 are precast and then cast with the precast bottom plate 1. The second concrete rib section 23 is in force transmission contact or connection with the precast bottom plate 1; this connection is implemented as the second concrete rib section 23 being pressed into the precast bottom plate 1 by 5 - 10 mm to achieve partial biting by the precast bottom plate 1, and a burr surface can be formed on the outer surface of the second concrete rib section 23 where it is pressed in. Furthermore, when the second concrete rib section 23 and the first concrete rib section 22 are precast, a temporary formwork can be used to form the second concrete rib section 23, or a non-removable steel mesh formwork can be used and fixed on the truss.

[0061] It is worth mentioning that in this embodiment, the steel structure of the prefabricated composite rib 2 at least includes the framework of the upper chord 211 and the web members 212; in another advantageous aspect, the steel structure of the prefabricated composite rib 2 may further include the lower chord 213, so as to form a truss 21 structure with the framework (the upper chord 211 and the web members 212). The two ends of the upper chord 211 can extend outside the edge of the precast bottom slab 1 to form a lapping section, and this lapping section can be welded to the laminated structural bars of the composite beam, or welded to the upper chord lapping sections of adjacent composite slabs to form a common force-bearing structure.

[0062] As an implementation manner of this embodiment, the upper chord 211, the lower chord 213 and the web members 212 can adopt strip structures such as steel bars, steel pipes, and section steels. Further, in this embodiment, the steel structure is preferably a truss 21, and the truss 21 steel bars adopt steel bars with diameters of 8, 6, and 4.5 (mm); the upper chord 211 steel bars adopt steel bars with a diameter of 8 (mm), and the bearing seat bars 214 are welded at the ends to increase the stiffness contribution of the rib and realize the continuity of the slab, so that the simply supported slab becomes a continuous slab.

[0063] As an implementation manner of this embodiment, the web members 212 of the truss 21 or the framework can adopt single-row web members, double-row web members, triangular web members, etc.

[0064] As an implementation manner of this embodiment, please refer to Figure 10 , the web members 212 of the truss 21 are U-shaped bars, the number of the upper chords 211 is two, which are respectively located on the bent bars extending outward on both sides of the top of the U-shaped bar, and the number of the lower chords 213 can be one, which is located on the horizontal bar at the bottom of the U-shaped bar. Preferably, the upper chord 211 steel bars adopt steel bars with a diameter of 6 (mm), and the web members 212 and the lower chords 213 adopt steel bars with a diameter of 5 (mm).

[0065] It is worth mentioning that, as known to those skilled in the art, it is common knowledge in the art to set multiple ribs on the precast bottom slab 1. Therefore, the number of the prefabricated composite ribs 2 in this embodiment is also multiple, and multiple prefabricated composite ribs 2 are arranged side by side at intervals on the precast bottom slab 1. It should be noted that this embodiment does not uniquely limit the number of the prefabricated composite ribs 2 on the precast bottom slab 1.

[0066] The beneficial effects of this embodiment: By adopting the composite rib, variable stiffness ribs are realized with the first concrete rib section 22 and the second concrete rib section 23. In the load concentration area (the area with the largest bending moment), the second concrete rib section 23 directly transfers force to the precast bottom slab 1 to meet greater stiffness requirements, and the first concrete rib section 22 is used to save materials in the non-load concentration area, so that the stiffness of the overall composite slab is increased by about 1.5 times compared with the traditional concrete rib composite slab.

[0067] The overall structure has a wider selection for the precast bottom slab 1, and prestressed bottom slabs, high-performance concrete bottom slabs, ordinary concrete bottom slabs, etc. can be selected. When a prestressed bottom slab is selected, in the load concentration area (the area with the largest bending moment), the second concrete rib section 23 is integrally cast with the precast bottom slab 1 or in force-transfer contact / connection, which can also prevent the precast bottom slab 1 from arching and can further reduce the thickness of the precast bottom slab 1.

[0068] In the precast composite rib 2, the steel structure can adopt a framework or a truss 21. When using a framework, the web member 212 is fixed to the structural reinforcement of the precast bottom slab 1. When using a truss 21, the lower chord 213 is fixed to the structural reinforcement of the precast bottom slab 1, which is simple and convenient.

[0069] For the variable stiffness precast composite rib 2 of this solution, the second concrete rib section 23 in the middle 30% area (with a larger bending moment) can be precast and formed in the factory or integrally formed with the precast bottom slab. In the 30% area of both side spans (with a smaller bending moment), the first concrete rib section 22 is precast in advance with UHPC rib and jointly forms a precast rib with the truss 21 steel bars to achieve industrialized production. In the 10% area at the end, it is directly the steel rib section 24 of the truss 21 steel bars, which is convenient for passing pipelines with a larger diameter.

[0070] The truss 21 steel bars adopt steel bars with diameters of 8, 6, and 4.5 mm. The upper chord 211 steel bars adopt 8 mm steel bars, and the support bars 214 are welded at the ends to increase the stiffness contribution of the rib and achieve the continuity of the slab, turning the simply supported slab into a continuous slab.

[0071] In the middle part (with a larger bending moment), a casting mesh plate 231 (steel mesh) is used to precast the pouring space of the second concrete rib section 23, and it is directly sleeved on the precast composite rib 2 in the factory for construction, improving the on-site construction efficiency.

[0072] Structural Embodiment 2: Please refer to Figure 5 and Figure 6 This embodiment discloses a precast composite rib for a composite slab, which at least includes a framework, two first concrete rib sections 22, and one second concrete rib section 23. Among them, the first concrete rib section 22 is formed by covering and molding on the upper chord 211 of the framework, and the second concrete rib section 23 is formed by covering and molding on the upper chord 211 of the framework and is located between the two first concrete rib sections 22. The bottom of the second concrete rib section 23 has a force-transfer contact surface with the precast bottom slab 1 of the composite slab, and the position of the force-transfer contact surface corresponds to the load concentration area of the composite slab.

[0073] Specifically, the first concrete rib section 22 and the second concrete rib section 23 are formed by covering the upper chord 211 with UHPC. Specifically, it is designed according to the span size of the composite slab. The first concrete rib section 22 is precast in the 30% area of both side spans (with a smaller bending moment), and the second concrete rib section 23 is cast and formed between the two first concrete rib sections 22. At this time, the second concrete rib section 23 can be directly formed by temporary formwork casting.

[0074] Similarly, the first concrete rib section 22 of the precast composite rib 2 and the section at the end of the framework form a steel rib section 24, which is implemented as a cable routing section for pipelines. Preferably, in a total of 10% of the area at both ends of the composite slab, the steel rib section 24 is directly the steel bars of the truss 21, facilitating the threading of pipelines with a larger diameter. It should be noted that the total 10% area at both ends of the composite slab is not the only limitation. Firstly, it does not limit its area parameters, and secondly, it does not limit its necessity. When the space below the first concrete rib section 22 of the precast composite rib 2 can complete the cable routing, the steel rib section 24 can be replaced by the extension of the first concrete rib section 22, forming a structure where the first concrete rib section 22 and the second concrete rib section 23 are of the same length as the slab span of the precast bottom slab 1.

[0075] Furthermore, the end of the first concrete rib section 22 facing the second concrete rib section 23 can be implemented as a vertical surface or a slope surface; the end of the second concrete rib section 23 is implemented as Figure 3 the slope surface shown, or is implemented as Figure 4 the vertical surface + slope surface shown, so as to prevent stress concentration with the change of the inclined surface.

[0076] The second concrete rib section 23 is in force transfer contact or connection with the precast bottom slab 1; this connection is implemented as the second concrete rib section 23 being pressed into the precast bottom slab 1 by 5 - 10 mm, achieving partial biting by the precast bottom slab 1, and a burr surface can be formed on the outer surface of the second concrete rib section 23 where it is pressed in. Further, when the second concrete rib section 23 and the first concrete rib section 22 are precast, temporary formwork can be used to form the second concrete rib section 23, or a non-removable steel mesh formwork can be used and fixed on the truss.

[0077] As described above, the entire precast composite rib 2 is implemented as a variable stiffness composite rib of 5% steel rib section 24 + 30% first concrete rib section 22 + 30% second concrete rib section 23 + 30% first concrete rib section 22 + 5% steel rib section 24, meeting the anti-bending moment requirements of different regions of the composite slab. It should be noted that this is a preferred implementation method of this embodiment and does not uniquely limit it. The proportion of each region can also be reasonably changed according to actual needs or span design.

[0078] Similarly, the steel structure of the precast composite rib 2 at least includes a framework of the upper chord 211 and the web members 212; in another advantageous aspect, the steel structure of the precast composite rib 2 can also include a lower chord 213, thus forming a truss 21 structure with the framework (upper chord 211 and web members 212).

[0079] As an implementation manner of this embodiment, the upper chord 211, the lower chord 213 and the web members 212 can adopt bar structures such as steel bars, steel pipes, and profiled steels. Further, in this embodiment, a steel structure is preferably used for the truss 21. The steel bars of the truss 21 are 8, 6, and 4.5 diameter steel bars (mm); the steel bars of the upper chord 211 are 8 diameter steel bars (mm), and seat bars 214 are welded at the ends to increase the stiffness contribution of the ribs and achieve the continuity of the slab, so that the simply supported slab becomes a continuous slab.

[0080] As an implementation manner of this embodiment, the web members 212 of the truss 21 or the frame can adopt single-row web members, double-row web members, triangular web members, etc.

[0081] As an implementation manner of this embodiment, please refer to Figure 10 , the web member 212 of the truss 21 is a U-shaped rod. The number of upper chords 211 is two, which are respectively located on the bent bars extending outward on both sides of the top of the U-shaped rod. The number of lower chords 213 can be one, which is located on the horizontal bar at the bottom of the U-shaped rod. Preferably, the steel bars of the upper chord 211 are 6 diameter steel bars (mm), and the web member 212 and the lower chord 213 adopt 5 diameter steel bars (mm).

[0082] The beneficial effects of this embodiment: The precast composite ribs 2 of this embodiment can be precast in large quantities in the factory. The first concrete rib section 22 and the second concrete rib section 23 are pre-cast and formed, and are transported in batches to the composite slab factory for the formation of the composite slab. The process is simple, and there is no need for secondary formwork or separate pouring of the first concrete rib section 22 and the second concrete rib section 23.

[0083] Structural Embodiment 3: Please refer to Figure 7 , Figure 8 and Figure 9 , this embodiment discloses a precast composite rib for a composite slab, which at least includes a frame and two first concrete rib sections 22; the first concrete rib sections 22 are formed by covering and molding on the upper chord 211 of the frame. A second concrete rib section forming space 230 is formed between the two first concrete rib sections 22. The second concrete rib section forming space 230 cooperates with the precast bottom slab 1 of the composite slab to integrally form a second concrete rib section 23. The second concrete rib section 23 and the precast bottom slab 1 form a continuous force transmission structure, and the continuous force transmission structure is located in the load concentration area of the composite slab.

[0084] Specifically, the first concrete rib section 22 is formed by covering the upper chord 211 with UHPC. Specifically, it is designed according to the span size of the composite slab. The first concrete rib section 22 is pre-cast at 30% of the two side spans (where the bending moment is smaller), and a second concrete rib section forming space 230 is formed between the two first concrete rib sections 22. Further, a pouring mesh plate 231 is arranged at the bottom and side of the second concrete rib section forming space 230, and the second concrete rib section forming space 230 is enclosed by the pouring mesh plate 231.

[0085] Specifically, the casting grid plate 231 at least includes a bottom plate 2313 and side plates 2311. The two side plates 2311 are located on both sides of the upper chord 211. There is a space between the first concrete rib section 22 and the top surface of the precast bottom plate 1. As a preferred embodiment of this embodiment, end plates 2312 are also provided at this space for blocking. Therefore, the casting and forming space of the second concrete rib section 23 is formed together by the side plates 2311 on both sides, the bottom plate 2313 at the bottom, and the end plates 2312 at the ends. Preferably, the elevation of the bottom plate 2313 should not be higher than the elevation of the formed top surface of the precast bottom plate 1.

[0086] Furthermore, a steel rib section 24 is formed between the first concrete rib section 22 of the precast composite rib 2 and the edge of the precast bottom plate 1. The steel rib section 24 is implemented as a wiring section for pipelines. Preferably, in a total of 10% of the areas at both ends of the composite slab, the steel rib section 24 is directly the steel bars of the truss 21, which is convenient for passing pipelines with a larger diameter.

[0087] As described above, the entire precast composite rib 2 is implemented as a variable-stiffness composite rib with 5% steel rib section 24 + 30% first concrete rib section 22 + 30% second concrete rib section 23 + 30% first concrete rib section 22 + 5% steel rib section 24, meeting the bending moment resistance requirements of different areas of the composite slab. It should be noted that this is a preferred embodiment of this embodiment and is not the only limitation. The proportion of each area can also be reasonably changed according to actual needs or span design.

[0088] It is worth mentioning that in this embodiment, the steel structure of the precast composite rib 2 at least includes a framework of the upper chord 211 and the web members 212; in another advantageous aspect, the steel structure of the precast composite rib 2 can also include a lower chord 213, so as to form a truss 21 structure with the framework (upper chord 211 and web members 212).

[0089] As an embodiment of this embodiment, the upper chord 211, the lower chord 213, and the web members 212 can adopt strip structures such as steel bars, steel pipes, and profiled steels. Furthermore, in this embodiment, the preferred steel structure is the truss 21, and the truss 21 steel bars adopt steel bars with diameters of 8, 6, and 4.5 (mm); the upper chord 211 steel bars adopt steel bars with a diameter of 8 (mm), and seat bars 214 are welded at the ends to increase the stiffness contribution of the rib and achieve the continuity of the slab, turning the simply supported slab into a continuous slab.

[0090] As an embodiment of this embodiment, the web members 212 of the truss 21 or the framework can adopt single-row web members, double-row web members, triangular web members, etc.

[0091] As an embodiment of this embodiment, please refer to Figure 10, the web member 212 of the truss 21 is a U-shaped rod. There are two upper chords 211, which are respectively located on the bent bars extending outward on both sides of the top of the U-shaped rod. The number of the lower chord 213 can be one, which is located on the horizontal bar at the bottom of the U-shaped rod. Preferably, the upper chord 211 is made of 6-diameter steel bars (mm), and the web member 212 and the lower chord 213 are made of 5-diameter steel bars (mm).

[0092] Advantages of this embodiment: The precast composite rib 2 of this embodiment can be precast in large quantities in the factory. The first concrete rib section 22 is precast and formed to reserve the forming space 230 for the second concrete rib section. It is transported in batches to the composite slab factory for the forming of the composite slab. The second concrete rib section 23 and the precast bottom slab 1 are integrally cast, making the integrity better and the bearing capacity stronger.

[0093] Method Embodiment 1: Please refer to Figure 1 、 Figure 3 and especially in combination with Figures 7 to 9 , this embodiment provides a method for forming a composite slab. This method mainly includes two core steps. One is the preparation of the precast composite rib 2, and the other is the precast of the composite slab (factory precast part). The core of this embodiment lies in the integral casting and forming of the second concrete rib section 23 and the precast bottom slab 1.

[0094] First, at least the upper chord 211 of the framework is precast and coated at intervals to form the first concrete rib section 22 to form the precast composite rib 2. A forming space 230 for the second concrete rib section is formed between at least two first concrete rib sections 22.

[0095] Specifically, as a preferred embodiment of this embodiment, the first concrete rib section 22 and the framework are combined and formed. The first concrete rib section 22 is formed by coating the upper chord 211 with UHPC. Specifically, it is designed according to the span size of the composite slab. The first concrete rib section 22 is precast at 30% of the two side spans (where the bending moment is smaller), and a forming space 230 for the second concrete rib section is formed between the two first concrete rib sections 22. Further, pouring mesh plates 231 are arranged at the bottom and side of the forming space 230 for the second concrete rib section, and the forming space 230 for the second concrete rib section is enclosed by the pouring mesh plates 231.

[0096] Specifically, the pouring mesh plate 231 at least includes a bottom plate 2313 and side plates 2311. The two side plates 2311 are located on both sides of the upper chord 211. There is a space between the top surface of the first concrete rib section 22 and the precast bottom slab 1. As a preferred embodiment of this embodiment, end plates 2312 are also arranged at this space for blocking. Therefore, the pouring and forming space for the second concrete rib section 23 is formed together by the side plates 2311 on both sides, the bottom plate 2313 at the bottom, and the end plates 2312 at the ends. Preferably, the elevation of the bottom plate 2313 should not be higher than the elevation of the formed top surface of the precast bottom slab 1.

[0097] Furthermore, a steel rib section 24 is formed between the first concrete rib section 22 of the precast composite rib 2 and the edge of the precast bottom plate 1, and the steel rib section 24 is implemented as a routing section for pipelines. Preferably, in a total of 10% of the area at both ends of the composite slab, the steel rib section 24 is directly the steel bars of the truss 21, which is convenient for routing pipelines with a larger diameter. It should be noted that the total 10% area at both ends of the composite slab is not the only limitation. Firstly, it does not limit its area parameters, and secondly, it does not limit its necessity. When the space below the first concrete rib section 22 of the precast composite rib 2 can complete the routing, the steel rib section 24 can be replaced by the extension of the first concrete rib section 22 to form a structure where the first concrete rib section 22 and the second concrete rib section 23 are of the same length as the span of the precast bottom plate 1.

[0098] Furthermore, the end of the first concrete rib section 22 facing the second concrete rib section 23 can be implemented as a vertical surface or a slope surface; the end of the second concrete rib section 23 is implemented as Figure 3 the slope surface shown, or is implemented as Figure 4 the vertical surface + slope surface shown, so as to prevent stress concentration with the change of the inclined surface.

[0099] As described above, the entire precast composite rib 2 is implemented as a variable stiffness composite rib of 5% steel rib section 24 + 30% first concrete rib section 22 + 30% second concrete rib section 23 + 30% first concrete rib section 22 + 5% steel rib section 24, meeting the anti-bending moment requirements of different regions of the composite slab. It should be noted that this is the preferred implementation mode of this embodiment and is not the only limitation. The proportion of each region also changes reasonably according to actual needs or span design.

[0100] It is worth mentioning that in this embodiment, the steel structure of the precast composite rib 2 at least includes a framework of upper chords 211 and web members 212; in another advantageous aspect, the steel structure of the precast composite rib 2 can also include a lower chord 213, so as to form a truss 21 structure with the framework (upper chords 211 and web members 212).

[0101] As an implementation mode of this embodiment, the upper chords 211, lower chords 213 and web members 212 can adopt strip structures such as steel bars, steel pipes, and section steels. Further, in this embodiment, the preferred steel structure is the truss 21, and the truss 21 steel bars adopt steel bars with diameters of 8, 6, and 4.5 (mm); the upper chord 211 steel bars adopt steel bars with a diameter of 8 (mm), and the end is welded with support bars 214 to increase the stiffness contribution of the rib and realize the continuity of the slab, turning the simply supported slab into a continuous slab.

[0102] As an implementation mode of this embodiment, the web members 212 of the truss 21 or the framework can adopt single-row web members, double-row web members, triangular web members, etc.

[0103] As an implementation mode of this embodiment, please refer to Figure 10, the web member 212 of the truss 21 is a U-shaped rod. There are two upper chords 211, which are respectively located on the bent bars extending outward on both sides of the top of the U-shaped rod. The number of the lower chord 213 can be one, which is located on the horizontal bar at the bottom of the U-shaped rod. Preferably, the upper chord 211 is made of steel bars with a diameter of 6 mm, and the web member 212 and the lower chord 213 are made of steel bars with a diameter of 5 mm.

[0104] It is worth mentioning that, as known to those skilled in the art, it is common knowledge in the art to provide multiple ribs on the precast bottom slab 1. Therefore, in this embodiment, the number of the precast composite ribs 2 is also multiple, and multiple precast composite ribs 2 are arranged side by side at intervals on the precast bottom slab 1. It should be noted that this embodiment does not uniquely limit the number of the precast composite ribs 2 on the precast bottom slab 1.

[0105] Then, the precast composite rib 2 is combined with the precast bottom slab 1 to pour and form a composite slab. At least the pouring space of the second concrete rib section 230 and the pouring space of the precast bottom slab 1 are integrally poured and formed to form the precast bottom slab 1 and the second concrete rib section 23. The second concrete rib section 23 and the precast bottom slab 1 form a continuous force transmission structure, and the continuous force transmission structure is located in the load concentration area of the composite slab.

[0106] Specifically, when installing the precast composite rib 2, if a framework is used, the web member 212 is fixed to the structural bars of the precast bottom slab 1. If a truss 21 is used, the lower chord 213 is fixed to the structural bars of the precast bottom slab 1.

[0107] Advantages of this embodiment: In this method, the second concrete rib section 23 and the precast bottom slab 1 of the composite slab are integrally poured and formed. By setting the pouring mesh plate 231 to form a pouring formwork, the mesh holes connect the second concrete rib section 23 and the precast bottom slab 1, further improving the structural stiffness and integrity.

[0108] The steel mesh prefabrication and the factory direct packaging method are adopted for construction, improving the on-site construction efficiency; between the second concrete rib section 23 and the precast bottom slab 1, the pouring mesh plate 231 is used for enclosure and plugging, realizing the simplified process of pouring the second concrete rib section 23 at the mid-span.

[0109] Method Embodiment 2: Please refer to Figure 2 , Figure 4 And especially in combination with Figures 5 to 6 , this embodiment provides a method for forming a composite slab. This method mainly includes two core steps. One is the preparation of the precast composite rib 2, and the other is the prefabrication of the composite slab (the factory prefabricated part). The core of this embodiment is that the second concrete rib section 23 and the first concrete rib section 22 are formed in the preparation stage of the precast composite rib 2, only different from the forming time of the second concrete rib section 23 in Method Embodiment 1.

[0110] First, at least the upper chord 211 of the truss is pre-cast and covered to form a first concrete rib section 22 and a second concrete rib section 23, and at least the second concrete rib section 23 is located between two first concrete rib sections 22 to form a precast composite rib 2.

[0111] Specifically, as a preferred embodiment of this Embodiment 1, the first concrete rib section 22, the second concrete rib section 23 and the truss are integrally formed. The first concrete rib section 22 and the second concrete rib section 23 are formed by covering the upper chord 211 with UHPC. Specifically, it is designed according to the span size of the composite slab. The first concrete rib section 22 is pre-cast at 30% of the two side spans (where the bending moment is small), and the second concrete rib section 23 is cast between the two first concrete rib sections 22. At this time, the second concrete rib section 23 can be directly formed by temporary formwork.

[0112] Specifically, after the second concrete rib section 23 is formed by temporary formwork, the formwork is removed. There is no limitation on the formwork for temporary formwork. It can be a casting mesh panel 231 or a wooden formwork, a steel formwork, etc. Preferably, the bottom elevation of the formwork for temporary formwork should not be higher than the formed top elevation of the precast bottom slab 1, and it is necessary to ensure that the second concrete rib section 23 is located within the casting space of the precast bottom slab 1 for connection, or in force transmission contact with the cast precast bottom slab 1. Further, a bolt connection can also be provided on the second concrete rib section 23 and engaged in the precast bottom slab 1 after the precast bottom slab 1 is cast to improve the connection integrity. This engagement form is implemented such that the second concrete rib section 23 is pressed into the precast bottom slab 1 by 5 - 10 mm to achieve partial engagement with the precast bottom slab 1, and a burr surface can be formed on the outer surface of the second concrete rib section 23 where it is pressed in. Further, when the first concrete rib section 22 and the second concrete rib section 23 are pre-cast, the second concrete rib section 23 can be formed by temporary formwork, or a non-removable steel mesh formwork can be used and fixed to the truss.

[0113] Similarly, a steel rib section 24 is formed between the first concrete rib section 22 of the precast composite rib 2 and the edge of the precast bottom slab 1, and the steel rib section 24 is implemented as a routing section for pipelines. Preferably, in a total of 10% of the area at both ends of the composite slab, it is directly the steel rib section 24 of the truss 21 steel bars, which is convenient for routing larger diameter pipelines. It should be noted that the total 10% area at both ends of the composite slab is not the only limitation. First, the area parameters are not restricted, and second, its necessity is not restricted. When the space below the first concrete rib section 22 of the precast composite rib 2 can complete the routing, the steel rib section 24 can be extended and replaced by the first concrete rib section 22 to form a structure where the first concrete rib section 22 and the second concrete rib section 23 are as long as the slab span of the precast bottom slab 1.

[0114] Furthermore, the end of the first concrete rib section 22 facing the second concrete rib section 23 can be implemented as a vertical surface or a slope surface; the end of the second concrete rib section 23 is implemented as Figure 3 the slope surface shown, or is implemented as Figure 4The vertical surface + ramp surface shown, thus preventing stress concentration with the change of the inclined surface.

[0115] As described above, the entire precast composite rib 2 is implemented as a variable stiffness composite rib of 5% steel rib section 24 + 30% first concrete rib section 22 + 30% second concrete rib section 23 + 30% first concrete rib section 22 + 5% steel rib section 24, meeting the anti-bending moment requirements of different regions of the composite slab. It should be noted that this is a preferred embodiment of this example and is not uniquely limited. The proportion of each region also changes reasonably according to actual needs or span design.

[0116] Similarly, the steel structure of the precast composite rib 2 at least includes a framework of upper chord 211 and web members 212; in another advantageous aspect, the steel structure of the precast composite rib 2 may further include a lower chord 213, thus forming a truss 21 structure with the framework (upper chord 211 and web members 212).

[0117] As an embodiment of this example, the upper chord 211, lower chord 213 and web members 212 can adopt strip structures such as steel bars, steel pipes, and steel sections. Further, in this example, the preferred steel structure is a truss 21, and the truss 21 steel bars adopt steel bars with diameters of 8, 6, and 4.5 (mm); the upper chord 211 steel bars adopt steel bars with a diameter of 8 (mm), and the end is welded with a support bar 214 to increase the stiffness contribution of the rib and realize the continuity of the slab, making the simply supported slab become a continuous slab.

[0118] As an embodiment of this example, the web members 212 of the truss 21 or the framework can adopt single-row web members, double-row web members, triangular web members, etc.

[0119] As an embodiment of this example, please refer to Figure 10 , the web member 212 of the truss 21 is a U-shaped bar, the number of upper chords 211 is two, which are respectively located on the bent bars extending outward on both sides of the top of the U-shaped bar, and the number of lower chords 213 can be one, which is located on the horizontal bar at the bottom of the U-shaped bar. Preferably, the upper chord 211 steel bars adopt steel bars with a diameter of 6 (mm), and the web members 212 and lower chords 213 adopt steel bars with a diameter of 5 (mm).

[0120] Then, the precast composite rib 2 is poured and formed in cooperation with the precast bottom slab 1, and at least the bottom end of the second concrete rib section 23 is in force-transferring contact with the precast bottom slab 1 to form a continuous force-transferring structure, and the continuous force-transferring structure is located in the load concentration area of the composite slab.

[0121] It should be noted that the "force-transferring contact" here includes the bottom surface of the second concrete rib section 23 abutting against the top surface of the precast bottom slab 1, and the degree of abutment should reach the level where action and reaction forces can be formed; it also includes that the bottom of the second concrete rib section 23 is partially buried in the precast bottom slab 1.

[0122] Specifically, when installing the precast composite rib 2, if a framework is used, the web member 212 is fixed to the structural reinforcement of the precast base plate 1; if a truss 21 is used, the lower chord 213 is fixed to the structural reinforcement of the precast base plate 1.

[0123] Advantages of this embodiment: The precast composite rib 2 of the present invention can be precast in large quantities in a factory. The first concrete rib section 22 and the second concrete rib section 23 are precast and formed, and then transported in batches to the composite slab factory for the formation of composite slabs. The process is simple and there is no need for secondary formwork for the first concrete rib section 22 and the second concrete rib section 23.

[0124] Furthermore, the present invention has been described in detail with reference to the embodiments in the accompanying drawings. Those of ordinary skill in the art can make various variations of the present invention based on the above description. Therefore, some details in the embodiments should not constitute a limitation to the present invention, and the scope of the present invention will be defined by the scope of the appended claims.

Claims

1. Laminated board, characterized in that, Comprising: Prefabricated bottom slab; Prefabricated composite ribs, the prefabricated composite ribs at least comprising a framework, a first concrete rib section and a second concrete rib section; The bottom of the framework is buried and fixed to the prefabricated bottom slab, the first concrete rib section is formed by covering and molding on the upper chord of the framework, a space is formed between the first concrete rib section and the prefabricated bottom slab, the second concrete rib section is formed by covering and molding on the upper chord of the framework, and the bottom of the second concrete rib section and the prefabricated bottom slab form a continuous force transmission structure, and the continuous force transmission structure is located in the load concentration area of the composite slab.

2. The laminated board according to claim 1, wherein: The continuous force transmission structure is implemented as being integrally cast and formed with the second concrete rib section and the prefabricated bottom slab; or, the second concrete rib section and the prefabricated bottom slab are in force transmission contact or connection.

3. The laminated board according to claim 1, wherein: The prefabricated composite ribs further comprise a lower chord, the lower chord is connected to the web members of the framework, and forms a truss with the web members and the upper chord, and the lower chord is buried and fixed to the prefabricated bottom slab.

4. The laminated board according to claim 3, wherein: There is also a support bar between the end of the lower chord and the end of the upper chord.

5. The laminated board according to claim 1, wherein: The position of the first concrete rib section corresponds to the non-load concentration area of the composite slab.

6. The laminated slab according to claim 5, wherein: The load concentration area is defined as the area with a larger mid-span bending moment of the composite slab; the non-load concentration area is defined as the area with a smaller bending moment at the side of the composite slab.

7. The laminated slab according to claim 1, 5 or 6, characterized in that: The number of the first concrete rib sections is at least two, and one second concrete rib section is located between the two first concrete rib sections.

8. The laminated board according to claim 7, characterized in that: A steel rib section is formed between the first concrete rib section of the prefabricated composite ribs and the edge of the prefabricated bottom slab, and the steel rib section is implemented as a wiring section for pipelines.

9. A method for forming a laminated slab according to any one of claims 1 to 8, characterized in that, Comprising: At least pre-casting the upper chord of the framework at intervals, covering and molding the first concrete rib section to form prefabricated composite ribs, and forming a forming space for the second concrete rib section between at least two first concrete rib sections; Cooperating the prefabricated composite ribs with the prefabricated bottom slab to cast and form a composite slab, and integrally casting and forming at least the forming space of the second concrete rib section and the casting space of the prefabricated bottom slab to form the prefabricated bottom slab and the second concrete rib section, and the second concrete rib section and the prefabricated bottom slab form a continuous force transmission structure, and the continuous force transmission structure is located in the load concentration area of the composite slab.

10. A method for forming a laminated plate as described in claim 9, characterized in that, Comprising: At least arranging casting mesh plates at the bottom and side of the forming space of the second concrete rib section, and the forming space of the second concrete rib section is enclosed by the casting mesh plates.

11. A method for forming a laminated slab according to any one of claims 1 to 8, characterized in that, Comprising: At least pre-casting the upper chord of the framework at intervals to cover and mold the first concrete rib section and the second concrete rib section to form prefabricated composite ribs, and at least the second concrete rib section is located between the two first concrete rib sections; Cooperating the prefabricated composite ribs with the prefabricated bottom slab to cast and form, and at least the bottom end of the second concrete rib section is in force transmission contact or connection with the prefabricated bottom slab to form a continuous force transmission structure, and the continuous force transmission structure is located in the load concentration area of the composite slab.

12. A precast composite rib for the laminated slab according to any one of claims 1 to 8, characterized in that, At least comprising a framework, two first concrete rib sections and one second concrete rib section; the first concrete rib section is formed by covering and molding on the upper chord of the framework, the second concrete rib section is formed by covering and molding on the upper chord of the framework and is located between the two first concrete rib sections, and the bottom of the second concrete rib section has a force transmission contact surface with the prefabricated bottom slab of the composite slab, and the position of the force transmission contact surface corresponds to the load concentration area of the composite slab.

13. A precast composite rib for the laminated slab according to any one of claims 1 to 8, characterized in that, It includes at least a framework and two first concrete rib segments; the first concrete rib segments are formed by wrapping on the upper chord of the framework, and a forming space for the second concrete rib segment is formed between the two first concrete rib segments. The forming space for the second concrete rib segment is integrally formed with the precast bottom slab of the composite slab to form the second concrete rib segment. The second concrete rib segment and the precast bottom slab form a continuous force transfer structure, and the continuous force transfer structure is located in the load concentration area of the composite slab.

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