Composite plate with dragon boat hanging rod to strengthen the bearing capacity of joints and preparation method thereof

Abstract

The invention discloses a composite slab provided with dragon boat hanging bars for strengthening the bearing capacity of a joint and a preparation method thereof. The composite slab comprises a dragon boat hanging bar net, a concrete precast slab without reinforcement on four sides, additional steel bars, a composite slab surface reinforcement net and a cast-in-place layer; two ends of the dragon boat hanging bars are bent upward at the end of the concrete precast slab without reinforcement on four sides and extend out of the concrete precast slab without reinforcement on four sides to form an upper bent hanging end, the end of the upper bent hanging end is processed into a hook-shaped structure, the upper bent hanging end extends out of the concrete precast slab without reinforcement on four sides to the composite slab surface reinforcement net in the cast-in-place layer, and the end hook-shaped structure of the upper bent hanging end is hooked on the longitudinal steel bars of the composite slab surface reinforcement net of the composite slab surface reinforcement net; the invention effectively improves the transmission capacity of shear force and bending moment at the joint between the precast slab and the surrounding components, improves the shear strength of the interface between the precast slab and the cast-in-place layer, effectively avoids the possibility of new and old concrete at the joint being cracked when subjected to a large load, thereby enhancing the reliability of the overall structure.

Description

Technical Field

[0001] The invention belongs to the technical field of building structures, and specifically relates to a composite plate structure and a construction method thereof, which adopts dragon boat suspension bars to strengthen the bearing capacity of joints. Background Art

[0002] Reinforced concrete composite slabs can combine the advantages of cast-in-place slabs and fully prefabricated slabs, and have the advantages of fast construction speed, short construction period, light weight of prefabricated components, good integrity, and saving of formwork. However, there are still some problems in its actual engineering application: the shear strength of the interface between the prefabricated body and the cast-in-place body of the composite slab is insufficient, which can easily cause relative displacement between the new and old concrete and lead to cracking; the moment and shear force transmission efficiency between the composite slab and the surrounding components is low, especially at the joints between the composite slab and the beam support, and the joints between the two prefabricated slabs, which are prone to large deformation and cracks. These problems are important obstacles to the promotion of prefabricated buildings.

[0003] The currently used four-side unreinforced composite slabs use additional steel bars to transmit force at the joints between the composite slabs and the surrounding components. The bending moment of the section at the joints is borne by the cast-in-place concrete layer and the additional steel bars. However, since there is no direct and effective overlap between the additional steel bars and the load-bearing longitudinal reinforcement in the precast slabs, the heights of the sections where the two types of steel bars are located are inconsistent, resulting in a sudden change in the section. The bearing capacity and stiffness of the nodes are significantly reduced, and weak points are easily formed at the node joints under both ordinary loads and earthquakes. Summary of the invention

[0004] Based on the shortcomings of the existing prefabricated concrete building main and secondary beam node connection forms, the present invention provides a composite board with a dragon boat hanger to strengthen the bearing capacity of the joint and a preparation method thereof. The composite board effectively improves the transmission capacity of shear force and bending moment at the joint between the prefabricated board and the surrounding components, and improves the shear strength of the interface between the prefabricated board and the cast-in-place layer, effectively avoiding the possibility of cracking of the new and old concrete at the joint when subjected to a large load, thereby enhancing the reliability of the overall structure.

[0005] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0006] The composite slab with dragon boat hanging bars to strengthen the bearing capacity of the joints includes a precast concrete slab without reinforcement on four sides, additional steel bars, a composite slab reinforcement mesh and a cast-in-place layer; a plurality of additional steel bars are longitudinally spaced on the upper surface of the precast concrete slab without reinforcement on four sides, one end of the additional steel bars is connected to the precast concrete slab without reinforcement on four sides, and the other end is connected to the surrounding components; the anchorage length of the additional steel bars in the precast concrete slab without reinforcement on four sides and the surrounding components and the spacing between two adjacent additional steel bars meet the requirements of the Technical Code for Prefabricated Concrete Structures and the Technical Code for Prefabricated Concrete Structure Buildings; the cast-in-place layer is formed by pouring concrete onto the precast concrete slab without reinforcement on four sides and the surrounding components; the cast-in-place layer constitutes a concrete composite slab tightly combined with the precast concrete slab without reinforcement on four sides; the surrounding components are another precast concrete slab without reinforcement on four sides, a concrete beam or a concrete wall;

[0007] The composite slab also includes a dragon boat hanging bar mesh, which is cast in the concrete precast slab without reinforcement on four sides; the dragon boat hanging bar mesh is mainly formed by binding a plurality of dragon boat hanging bars arranged at longitudinal intervals and a plurality of concrete precast slab distribution steel bars arranged at transverse intervals to form a grid; the two ends of the dragon boat hanging bars are bent upward at the end of the concrete precast slab without reinforcement on four sides and extend out of the concrete precast slab without reinforcement on four sides to form an upper bent hanging end, the end of the upper bent hanging end is processed into a hook-shaped structure, the upper bent hanging end extends out of the concrete precast slab without reinforcement on four sides to the composite slab reinforcement net in the cast-in-place layer, and the end hook-shaped structure of the upper bent hanging end is hooked on the longitudinal steel bars of the composite slab reinforcement net of the composite slab reinforcement net; the distribution spacing of the dragon boat hanging bars and the distribution spacing of the longitudinal steel bars of the composite slab reinforcement net should meet the spacing of the force-bearing steel bars in the plate of the "Code for Design of Concrete Structures" GB 50010-2010.

[0008] To further achieve the purpose of the present invention, preferably, the dragon boat hanging bar net also includes compression bars; at least one compression bar is transversely arranged at both ends of a plurality of spaced dragon boat hanging bars at the ends of the concrete precast panels without reinforcement on four sides and bent upward, and the compression bars are tied to the dragon boat hanging bars, and the compression bars constitute the steel bars transversely arranged in the dragon boat hanging bar net.

[0009] Preferably, the compression reinforcement is 2-3 steel bars arranged at intervals of 30mm to 50mm, and each compression reinforcement is tied to the dragon boat suspension reinforcement.

[0010] Preferably, the distance between the bent part of the upper bent end of the dragon boat hanging bar and the edge of the precast concrete slab without reinforcement on four sides is not less than 15 mm.

[0011] Preferably, the length of the hook-shaped structure of the upper curved hanging end is 5 to 7 times the diameter of the dragon boat hanging rod.

[0012] Preferably, both ends of the dragon boat hanging rod are bent upward by 90° at the ends of the concrete precast slab without reinforcement on four sides.

[0013] Preferably, the dragon boat hanging bars 4 of the dragon boat hanging bar net and the longitudinal steel bars of the composite plate surface reinforcement net in the composite plate surface reinforcement net are on the same vertical plane.

[0014] Preferably, when the dragon boat hanging bars of the dragon boat hanging bar net and the longitudinal steel bars of the composite plate reinforcement net in the composite plate reinforcement net are not on the same vertical plane, the bent ends of the dragon boat hanging bars are tilted and hooked on the adjacent longitudinal steel bars of the composite plate reinforcement net in the composite plate reinforcement net, or additional longitudinal steel bars of the composite plate reinforcement net are added to the composite plate reinforcement net in a straight line with the bent ends of the dragon boat hanging bars at both ends, to ensure that the bent ends of the dragon boat hanging bars can be hooked on the longitudinal steel bars of the composite plate reinforcement net.

[0015] Preferably, the concrete beam is a cast-in-place negative electrode composite beam; the composite beam is a composite beam side beam prefabricated body or a composite beam middle beam prefabricated body; the composite beam side beam prefabricated body or the composite beam middle beam prefabricated body is a rectangular reinforced concrete member with a through rectangular groove on the upper part.

[0016] The method for preparing the composite plate provided with dragon boat hanging bars to strengthen the bearing capacity of the joints comprises the following steps:

[0017] a. Bend the steel bar upwards and process the end of the steel bar into a hook shape to make a dragon boat hanging bar with an upper bent end;

[0018] b. Tie the dragon boat hanging reinforcement net inside the prefabricated board formwork in the prefabrication plant to ensure that the upper bend hanging end extends out of the prefabricated board to the height of the composite board reinforcement net. After tying the dragon boat hanging reinforcement net, pour and maintain it to reach the designed strength;

[0019] c. Transport and hoist the precast concrete slab with dragon boat lifting reinforcement net to the designed location;

[0020] d. Additional reinforcements are installed at intervals on the precast concrete slab with the dragon boat hanging reinforcement mesh, and the composite slab reinforcement mesh is tied;

[0021] e. Hook the hook-shaped structures at the ends of the upper curved ends of the dragon boat lifting bars at both ends of the dragon boat lifting bar net onto the longitudinal steel bars of the laminated plate reinforcement net;

[0022] f. Pour cast-in-place concrete on the composite slab surface reinforcement mesh and surrounding components and vibrate to ensure a tight connection between the composite slab and surrounding components, forming a composite slab with strong bearing capacity at the joints and equipped with dragon boat suspension bars to strengthen the bearing capacity at the joints.

[0023] The concept of the present invention is as follows: by changing the longitudinal reinforcement of the steel mesh of the traditional concrete precast panel, at the node where the concrete precast panel 1 without reinforcement on the four sides is connected to the surrounding components, the dragon boat hanging bar mesh in the precast panel 1 is connected to the composite panel surface reinforcement mesh 7 in the cast-in-place layer 3 to form a whole, so as to enhance the bending moment and shear force transmission performance of the composite panel at the node joint, and it is hoped that by connecting the precast panel steel mesh with the composite panel surface reinforcement mesh 7, the connection between the new and old concrete is enhanced to prevent the relative movement of the precast panel and the cast-in-place layer under the action of shear force when loaded, thereby causing cracking of the interface between the new and old concrete. The dragon boat hanging bar 4 connects the dragon boat hanging bar mesh in the concrete precast panel 1 without reinforcement on the four sides and the composite panel surface reinforcement mesh 7 in the cast-in-place layer 3 to form a whole through the upper curved hanging end 4a, so as to achieve the above purpose.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] 1. The upper curved end of the dragon boat hanging bar net extends into the cast-in-place layer, which strengthens the connection between the new and old concrete and limits the relative displacement between the precast slab and the cast-in-place layer under the action of shear force.

[0026] 2. The dragon boat lifting rod hangs the surface reinforcement of the composite plate through the upward bending lifting end hook, making full use of the tensile strength of the surface reinforcement of the composite plate to form a whole with the steel mesh in the composite plate, thus improving the structure's ability to transmit bending moment and shear force at the joints between the composite plate and surrounding components, thereby greatly improving the rigidity and bearing capacity of the structure.

[0027] 3. The dragon boat sling with an upward curved end can be formed by simply bending and hooking the steel bars. The structure is simple and the production process can be efficiently completed through an automated production line.

[0028] 4. The concrete precast panels using dragon boat hangers can achieve the goal of no steel bars sticking out around the precast panels. There is no need to make new templates according to the different reinforcement conditions of the precast panels, which reduces the consumption of steel templates and the cost of precast panels. It has extremely high economic efficiency and also improves the production efficiency of the component prefabrication plant to a certain extent, which is in line with the economic and efficient characteristics of prefabricated buildings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The composite slab is provided with dragon boat hanging rods to strengthen the bearing capacity of the joints;

[0030] Figure 2 for Figure 1 Isometric view of the dragon boat suspension network;

[0031] Figure 3 for Figure 1 The main view of the dragon boat suspension net;

[0032] Figure 4 for Figure 1 A top view of the dragon boat suspension net;

[0033] Figure 5 for Figure 1 Side view of the dragon boat suspension net;

[0034] Figure 6 for Figure 1 Schematic diagram of the dragon boat suspension rod;

[0035] Figure 7 It is an isometric view of a prefabricated part of a concrete precast panel and a composite beam of the present invention;

[0036] Figure 8 It is a front view of the node of the concrete composite slab and the composite beam of the present invention;

[0037] Fig. 9 It is a side view of a node of a concrete composite slab and a composite beam of the present invention;

[0038] Fig.10 It is a front view of the node between the concrete composite slab and the composite beam edge beam of the present invention;

[0039] Fig.11 It is a front view of the middle beam node of the concrete composite slab and the composite beam of the present invention;

[0040] Fig.12 It is an isometric diagram of a concrete precast panel and a concrete precast panel node of the present invention;

[0041] Fig.13 It is a side view of a concrete precast panel and a concrete precast panel node of the present invention;

[0042] Fig.14 It is a front view of a concrete precast panel and a concrete precast panel node of the present invention;

[0043] The figure shows: a precast concrete slab 1 without reinforcement on all four sides, a precast composite side beam 2a, a precast composite middle beam 2b, a cast-in-place layer 3, a dragon boat hanger 4, an upper bent hanger 4a, a compression rib 5, additional reinforcement 6, a composite slab reinforcement mesh 7, longitudinal reinforcement 7a of the composite slab reinforcement mesh, and distributed reinforcement 8 for the precast concrete slab. DETAILED DESCRIPTION

[0044] To better support the present invention, the present invention is further described below in conjunction with the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0045] like Figure 1-Figure 6As shown, a composite slab provided with dragon boat hanging bars to strengthen the bearing capacity of the joints, comprises a concrete precast slab 1 without reinforcement on four sides, a dragon boat hanging bar net, additional steel bars 6, a composite slab surface reinforcement net 7 and a cast-in-place layer 3; the dragon boat hanging bar net is cast in the concrete precast slab without reinforcement on four sides; the dragon boat hanging bar net is mainly formed by binding a plurality of dragon boat hanging bars 4 arranged at longitudinal intervals and a plurality of concrete precast slab distribution steel bars 8 arranged at transverse intervals to form a grid shape; the two ends of the dragon boat hanging bar 4 are bent upward at the end of the concrete precast slab 1 without reinforcement on four sides and extend out of the concrete precast slab 1 without reinforcement on four sides to form an upper bent hanging end 4a, the end of the upper bent hanging end 4a is processed into a hook-shaped structure, the upper bent hanging end 4a extends out of the concrete precast slab 1 without reinforcement on four sides to the composite slab surface reinforcement net 7 in the cast-in-place layer 3, and the hook-shaped structure at the end of the upper bent hanging end 4a is hooked on the composite slab surface reinforcement net longitudinal steel bar 7a of the composite slab surface reinforcement net 7; A plurality of additional steel bars 6 are longitudinally spaced on the upper end surface of the reinforced concrete precast panel 1, one end of the additional steel bars 6 is connected to the concrete precast panel 1 without reinforcement on four sides, and the other end is connected to the surrounding components; the anchorage length of the additional steel bars 6 in the concrete precast panel 1 without reinforcement on four sides and the surrounding components and the spacing between two adjacent additional steel bars 6 meet the requirements of the Technical Code for Prefabricated Concrete Structures and the Technical Code for Prefabricated Concrete Structure Buildings; the cast-in-place layer 3 is formed by pouring concrete onto the concrete precast panel 1 without reinforcement on four sides and the surrounding components; the cast-in-place layer 3 constitutes a concrete composite slab tightly combined with the concrete precast panel 1 without reinforcement on four sides; the surrounding components are another concrete precast panel 1 without reinforcement on four sides, a concrete beam or a concrete wall; the distribution spacing of the dragon boat hanger bars 4 and the distribution spacing of the longitudinal steel bars 7a of the composite panel surface reinforcement mesh shall meet the spacing of the force-bearing steel bars in the plate of the Code for Design of Concrete Structures GB 50010-2010.

[0046] Preferably, the dragon boat lifting bar net also includes compression bars 5; at least one compression bar 5 is transversely arranged at both ends of the multiple spaced dragon boat lifting bars 4 at the ends of the concrete precast slab 1 that bends upward without reinforcement on the four sides, and the compression bars 5 are tied to the dragon boat lifting bars 4 to improve the pull-out resistance of the dragon boat lifting bars 4 when subjected to load. It is further preferred that 2-3 compression bars 5 are arranged at intervals of 30mm-50mm, and each compression bar 5 is tied to the dragon boat lifting bar 4.

[0047] Preferably, the distance between the bent portion of the upper bent end 4a of the dragon boat hanging bar 4 and the edge of the precast concrete slab 1 without reinforcement on four sides is not less than 15 mm.

[0048] Preferably, the length of the hook-shaped structure of the upper curved hanging end 4a is 5 to 7 times the diameter of the dragon boat hanging rod, thereby ensuring the connection strength between the dragon boat hanging rod and the ribs.

[0049] Preferably, both ends of the dragon boat hanging rod 4 are bent upward by 90° at the end of the concrete precast slab 1 without reinforcement on four sides.

[0050] Preferably, the dragon boat hanging bars 4 in the dragon boat hanging bar net and the longitudinal steel bars 7a of the composite plate rib net in the composite plate rib net 7 are arranged correspondingly up and down, that is, the dragon boat hanging bars 4 of the dragon boat hanging bar net and the longitudinal steel bars 7a of the composite plate rib net in the composite plate rib net 7 are on the same vertical plane; ensure that the upper bent hanging end 4a of the dragon boat hanging bar 4 can be hooked on the longitudinal steel bars 7a of the composite plate rib net 7.

[0051] When the dragon boat hanging bar 4 of the dragon boat hanging bar net and the longitudinal reinforcement 7a of the composite plate reinforcement net 7 are not on the same vertical plane, the upward bent hanging end 4a of the dragon boat hanging bar 4 is tilted and hooked on the adjacent longitudinal reinforcement 7a of the composite plate reinforcement net 7, or additional longitudinal reinforcement 7a of the composite plate reinforcement net are provided on the composite plate reinforcement net 7 on the same line as the upward bent hanging ends 4a at both ends of the dragon boat hanging bar 4, to ensure that the upward bent hanging end 4a of the dragon boat hanging bar 4 can be hooked on the longitudinal reinforcement 7a of the composite plate reinforcement net 7, so that the steel mesh in the composite plate forms a whole that is subjected to common force.

[0052] Preferably, the concrete beam is a cast-in-place negative electrode composite beam; the composite beam is a composite beam side beam prefabricated body 2a or a composite beam middle beam prefabricated body 2b; the composite beam side beam prefabricated body 2a or the composite beam middle beam prefabricated body 2b is a rectangular reinforced concrete member with a rectangular groove through the upper part.

[0053] like Figure 7-Figure 11As shown, the composite slab and composite beam connection device with dragon boat hanging bars to strengthen the bearing capacity of the joints includes a precast concrete slab 1 without reinforcement on four sides, a composite beam side beam precast body 2a, a composite beam middle beam precast body 2b, a dragon boat hanging bar mesh, additional steel bars 6, a composite slab surface reinforcement mesh 7 and an upper cast-in-place layer 3. The composite beam side beam precast body 2a and the composite beam middle beam precast body 2b are rectangular reinforced concrete components with rectangular grooves penetrating through the upper part. When the composite slab is connected with the composite beam, the two sides of the four-side unreinforced concrete precast slab 1 with the dragon boat hanging bar net are placed on the upper surface edges of the composite beam side beam precast body 2a and the composite beam middle beam precast body 2b respectively. After the composite slab surface reinforcement net 7 is tied, according to the design situation, the upper curved hanging end 4a exposed on the surface of the four-side unreinforced concrete precast slab 1 is hooked on the longitudinal reinforcement 7a of the composite slab surface reinforcement net, and the additional reinforcement 6 is placed on the upper surface of the four-side unreinforced concrete precast slab 1 with the spacing and anchorage length designed according to the "Technical Code for Prefabricated Concrete Structures" (JGJ 1-2014) and "Technical Code for Prefabricated Concrete Structure Buildings" (GBT51231-2016). Finally, the cast-in-place layer 3 is poured. The cast-in-place layer 3 is combined with the four-side unreinforced concrete precast slab 1, the composite beam side beam precast body 2a, and the composite beam middle beam precast body 2b to form a composite slab and a composite beam. The conventional four-side unreinforced composite slab mainly transmits force to the composite beams on both sides through the cast-in-place concrete. Since the additional steel bars are not directly overlapped with the steel mesh in the precast slab, the force transmission capacity is relatively weak, which easily leads to cracks at the joints between the composite slab and the composite beam. The upper curved hanging end 4a of the dragon boat hanging bar 4 can realize the direct transmission of shear force and bending moment between the dragon boat hanging bar mesh in the four-side unreinforced concrete precast slab 1 and the composite slab surface reinforcement mesh 7 in the cast-in-place layer, making full use of the tensile strength of the longitudinal steel bars 7a of the composite slab surface reinforcement mesh, reducing the stress on the cast-in-place layer 3 concrete, and reducing the possibility of cracks at the joints between the composite slab and the composite beam.

[0054] Figure 12-14As shown, a connecting device for a composite slab provided with dragon boat hanging bars to strengthen the bearing capacity at the joints and another composite slab provided with dragon boat hanging bars to strengthen the bearing capacity at the joints comprises a precast concrete slab 1 without reinforcement on four sides, a dragon boat hanging bar mesh, additional steel bars 6, a composite slab surface reinforcement mesh 7 and an upper cast-in-place layer 3; the height of the upper curved hanging end 4a is set to reach the height of the composite slab surface reinforcement mesh 7 so as to hook the longitudinal steel bars 7a of the composite slab surface reinforcement mesh; the length of the upper curved hanging end 4a extending out of the precast concrete slab 1 without reinforcement on four sides is equal to the thickness of the cast-in-place layer 3 minus the thickness of the concrete protective layer. When the composite slab is connected to the composite slab, the concrete precast slab 1 with the dragon boat hanging bar mesh without reinforcement on the four sides is first hoisted to the designed position, and after the composite slab surface reinforcement mesh 7 is tied, the upper curved hanging end 4a of the dragon boat hanging bar is hooked on the longitudinal reinforcement 7a of the composite slab surface reinforcement mesh in the composite slab surface reinforcement mesh 7, so as to ensure that the bending moment and shear force are transmitted between the dragon boat hanging bar 4 and the longitudinal reinforcement 7a of the composite slab surface reinforcement mesh through the connection of the upper curved hanging end 4a. The horizontal distribution of the dragon boat hanging bar 4 in the concrete precast slab and the longitudinal reinforcement 7a of the composite slab surface reinforcement mesh in the cast-in-place layer 3 should be kept uniform, so as to ensure that the upper curved hanging end 4a of the dragon boat hanging bar can be hooked on the longitudinal reinforcement 7a of the composite slab surface reinforcement mesh, and the reinforcement mesh in the composite slab forms a whole body that is subjected to common force. The additional steel bars 6 are placed on the upper surface of the precast concrete slab 1 without reinforcement on four sides according to the design requirements. The spacing and anchorage length of the additional steel bars 6 shall meet the relevant provisions of the Technical Code for Prefabricated Concrete Structures (JGJ 1-2014) and the Technical Code for Prefabricated Concrete Structure Buildings (GBT51231-2016). Finally, the cast-in-place layer 3 is cast, and the cast-in-place layer 3 is tightly combined with the precast concrete slab 1 without reinforcement on four sides to form a composite slab. The close joints between the traditional precast concrete slabs 1 without reinforcement on four sides cannot transmit the bending moment. The bending moment in the composite slab is mainly transmitted by the cast-in-place layer 3 and the composite slab surface reinforcement mesh 7 in the cast-in-place layer. Due to the lack of steel connection between the precast concrete slab 1 without reinforcement on four sides and the cast-in-place layer 3, the bending moment in the precast concrete slab 1 without reinforcement on four sides cannot be effectively transmitted, which easily leads to cracks in the joints between the precast slabs and the junction of the new and old concrete layers around the joints. The upward curved hanging end 4a of the dragon boat hanging bar connects the dragon boat hanging bar net in the precast panel with the composite panel surface bar net 7 in the composite panel, so that the bending moment in the precast panel 1 can be effectively transmitted through the composite panel surface bar net 7 in the cast-in-place layer 3, reducing the possibility of cracking in the joint between the two precast panels. At the same time, the upward curved hanging end 4a penetrates the new and old concrete layers, closely connecting the new and old concrete layers, and also reducing the possibility of cracking at the junction of the new and old concrete layers around the joint.

[0055] The present invention is implemented through the following construction method: in a component prefabrication plant, the steel bars are bent 90 degrees according to design requirements and the ends of the steel bars are processed into a hook shape to form a dragon boat hanging bar 4 with an upper bent hanging end; the dragon boat hanging bar net is tied in the template of the concrete prefabricated slab 1 without reinforcement on four sides of the component prefabrication plant to ensure that the upper bent hanging end 4a is perpendicular to the upper surface of the concrete prefabricated slab 1 without reinforcement on four sides; the height of the upper bent hanging end 4a should reach the height of the composite plate surface reinforcement net 7 so as to hook the longitudinal steel bars 7a of the composite plate surface reinforcement net; the length of the upper bent hanging end 4a extending out of the concrete prefabricated slab 1 without reinforcement on four sides is equal to the thickness of the cast-in-place layer 3 minus the thickness of the concrete protective layer. After the binding is completed, the concrete precast panel 1 without reinforcement on four sides is poured with concrete, and the upper surface of the concrete precast panel 1 without reinforcement on four sides is roughened; after the concrete precast panel 1 without reinforcement on four sides is cured to reach the design strength, the concrete precast panel 1 without reinforcement on four sides is transported and hoisted to the designed position, which can be placed on the precast part of the composite beam or closely connected with other precast panels with dragon boat hanging bars according to the specific design situation; the additional steel bars 6 are placed on the upper surface of the concrete precast panel 1 with reinforcement on four sides according to the design requirements, and the spacing and anchorage length of the additional steel bars 6 shall meet the relevant provisions of the "Technical Code for Prefabricated Concrete Structures" (JGJ 1-2014) and the "Technical Code for Prefabricated Concrete Structure Buildings" (GBT51231-2016). And tie the composite plate surface reinforcement mesh 7; hook the upper bent end 4a of the dragon boat suspension mesh on the longitudinal reinforcement 7a of the composite plate surface reinforcement mesh; pour the cast-in-place layer 3 concrete and vibrate it to form a structure with strong bearing capacity that is closely connected between the composite plate and the composite beam, and between the composite plates and the composite plates at the joints.

[0056] The present invention is not limited to the above-mentioned specific implementation modes. According to the above-mentioned contents, in accordance with the common technical knowledge and customary means in the field, without departing from the above-mentioned basic technical ideas of the present invention, the present invention can also make other various forms of equivalent modifications, replacements or changes, all of which fall within the protection scope of the present invention.

Claims

1. A composite slab with dragon boat hanging bars to strengthen the bearing capacity of the joints includes a precast concrete slab without reinforcement on four sides, additional steel bars, a composite slab reinforcement mesh and a cast-in-place layer; a plurality of additional steel bars are longitudinally spaced on the upper surface of the precast concrete slab without reinforcement on four sides, one end of the additional steel bars is connected to the precast concrete slab without reinforcement on four sides, and the other end is connected to the surrounding components; the anchorage length of the additional steel bars in the precast concrete slab without reinforcement on four sides and the surrounding components and the spacing between two adjacent additional steel bars meet the requirements of the Technical Code for Prefabricated Concrete Structures and the Technical Code for Prefabricated Concrete Structure Buildings; the cast-in-place layer is formed by pouring concrete onto the precast concrete slab without reinforcement on four sides and the surrounding components; the cast-in-place layer constitutes a concrete composite slab tightly combined with the precast concrete slab without reinforcement on four sides; the surrounding components are another precast concrete slab without reinforcement on four sides, a concrete beam or a concrete wall; Features: The composite slab also includes a dragon boat hanging bar mesh, which is cast in the concrete precast slab without reinforcement on four sides; the dragon boat hanging bar mesh is mainly formed by binding a plurality of dragon boat hanging bars arranged at longitudinal intervals and a plurality of concrete precast slab distribution steel bars arranged at transverse intervals to form a grid; the two ends of the dragon boat hanging bars are bent upward at the end of the concrete precast slab without reinforcement on four sides and extend out of the concrete precast slab without reinforcement on four sides to form an upper bent hanging end, the end of the upper bent hanging end is processed into a hook-shaped structure, the upper bent hanging end extends out of the concrete precast slab without reinforcement on four sides to the composite slab reinforcement net in the cast-in-place layer, and the end hook-shaped structure of the upper bent hanging end is hooked on the longitudinal steel bars of the composite slab reinforcement net of the composite slab reinforcement net; the distribution spacing of the dragon boat hanging bars and the distribution spacing of the longitudinal steel bars of the composite slab reinforcement net should meet the spacing of the force-bearing steel bars in the plate of the "Code for Design of Concrete Structures" GB 50010-2010.

2. The composite plate with dragon boat hanging rods to strengthen the bearing capacity of the joints according to claim 1, characterized in that: The dragon boat hanging bar net also includes compression bars; at least one compression bar is transversely arranged at both ends of a plurality of spaced dragon boat hanging bars at the ends of the concrete precast panels that are bent upward without reinforcement on all four sides, and the compression bars are tied to the dragon boat hanging bars, and the compression bars constitute the transversely arranged steel bars in the dragon boat hanging bar net.

3. The composite plate with dragon boat hanging rods to strengthen the bearing capacity of the joints according to claim 2 is characterized in that: The compression reinforcement is 2-3 steel bars arranged at intervals of 30mm-50mm, and each compression reinforcement is tied to the dragon boat suspension reinforcement.

4. The composite plate with dragon boat hanging rods to strengthen the bearing capacity of the joints according to claim 1, characterized in that: The distance between the bent part of the upper bent end of the dragon boat hanging bar and the edge of the concrete precast slab without reinforcement on four sides is not less than 15mm.

5. The composite plate with dragon boat hanging rods to strengthen the bearing capacity of the joints according to claim 1, characterized in that: The length of the hook-shaped structure at the upper curved hanging end is 5 to 7 times the diameter of the dragon boat hanging rod.

6. The composite plate with dragon boat hanging rods to strengthen the bearing capacity of the joints according to claim 1, characterized in that: The two ends of the dragon boat hanging rod are bent upward by 90 degrees at the end of the concrete precast slab without reinforcement on four sides.

7. The composite plate with dragon boat hanging rods to strengthen the bearing capacity of the joints according to claim 1, characterized in that: The dragon boat suspension bars (4) of the dragon boat suspension bar net are on the same vertical plane as the longitudinal steel bars of the composite plate surface reinforcement net in the composite plate surface reinforcement net.

8. The composite plate with dragon boat hanging rods to strengthen the bearing capacity of the joints according to claim 1, characterized in that: When the dragon boat hanging bars of the dragon boat hanging bar mesh and the longitudinal reinforcement of the composite slab reinforcement mesh in the composite slab reinforcement mesh are not in the same vertical plane, the bent end of the dragon boat hanging bar is tilted and hooked on the adjacent longitudinal reinforcement of the composite slab reinforcement mesh in the composite slab reinforcement mesh, or additional longitudinal reinforcement of the composite slab reinforcement mesh is added to the composite slab reinforcement mesh in a straight line with the bent ends of the dragon boat hanging bars at both ends, to ensure that the bent end of the dragon boat hanging bar can be hooked on the longitudinal reinforcement of the composite slab reinforcement mesh of the composite slab reinforcement mesh.

9. The composite plate with dragon boat hanging rods to strengthen the bearing capacity of the joints according to claim 1, characterized in that: The concrete beam is a negative pole composite beam of a cast-in-place beam; the composite beam is a composite beam side beam prefabricated body or a composite beam middle beam prefabricated body; the composite beam side beam prefabricated body or the composite beam middle beam prefabricated body is a rectangular reinforced concrete component with a rectangular groove penetrating the upper part.

10. The method for preparing the composite slab with dragon boat hanging bars to strengthen the bearing capacity of the joints as claimed in claim 1, characterized in that The following steps are involved: a. Bend the steel bar upwards and process the end of the steel bar into a hook shape to make a dragon boat hanging bar with an upper bent end; b. Tie the dragon boat hanging reinforcement net inside the prefabricated board formwork in the prefabrication plant to ensure that the upper bend hanging end extends out of the prefabricated board to the height of the composite board reinforcement net. After tying the dragon boat hanging reinforcement net, pour and maintain it to reach the designed strength; c. Transport and hoist the precast concrete slab with dragon boat lifting reinforcement net to the designed location; d. Additional reinforcements are installed at intervals on the precast concrete slab with the dragon boat hanging reinforcement mesh, and the composite slab reinforcement mesh is tied; e. Hook the hook-shaped structures at the ends of the upper curved ends of the dragon boat lifting bars at both ends of the dragon boat lifting bars net onto the longitudinal steel bars of the laminated plate reinforcement net; f. Pour cast-in-place concrete on the composite slab surface reinforcement mesh and surrounding components and vibrate to ensure a tight connection between the composite slab and surrounding components, forming a composite slab with strong bearing capacity at the joints and equipped with dragon boat suspension bars to strengthen the bearing capacity at the joints.

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