Post-tensioned prestressed reinforced concrete floor system skeleton structure and floor system construction method

Abstract

The invention relates to the field of building construction, and discloses a post-tensioned prestressed reinforced concrete floor system structure and a floor system construction method.The floor system framework structure is integrally in a #-shaped grid shape and comprises column caps, the column caps are located at the four corners of a floor system framework, and the column caps are located at the upper ends of structural columns arranged at the four corners; the node modules are distributed at cross node positions of the net-shaped structure; the two ends of the beam mold are connected with the node mold to form a #-shaped frame of the floor system framework; the plate mold is laid in a #-shaped lattice in a #-shaped lattice frame formed by the beam mold and the node mold, and the edge part of the plate mold is connected with the beam mold for supporting; the reinforcing mesh is laid on the node mold, the plate mold and the beam mold to serve as a framework of post-cast reinforced concrete; the steel strand is laid in the beam formwork, and the two ends of the steel strand are connected to the tensioning pedestal; the steel strand is a post-tensioned prestressed steel strand. The scheme has the advantages of simplicity in construction, low cost, large bearing load and the like.

Description

Technical Field

[0001] The present invention relates to the field of construction, and mainly relates to a post-tensioned prestressed reinforced concrete floor skeleton structure and a floor construction method. Background Art

[0002] The traditional cast-in-situ reinforced concrete frame structure is the most commonly used structural form in current industrial and civil buildings. Due to the properties of reinforced concrete materials and the mechanical characteristics, the column grid size and floor load of this structural form are limited. However, for some industrial factories and civil buildings such as civil warehouse yards, cold storages, and supermarkets, the live loads required for functional use are often at least above 10 kN, often 50 kN, and even close to 100 kN for production functions. It is very difficult for the previous ordinary reinforced concrete frame structures to bear such large live loads. For this reason, technologies such as steel structure technology have been developed, but problems such as anti-corrosion and fire protection exist. Some prestressed reinforced concrete technologies have also been developed, as well as prefabricated structures such as an assembled floor system disclosed in CN204386002U, but ultimately the problem of the floor structure for multi-story large loads has not been perfectly solved. Currently, the engineering community has taken the construction of industrial and civil buildings with large loads as a new research and development direction. Summary of the Invention

[0003] The present invention aims at the deficiencies in the prior art and provides a post-tensioned prestressed reinforced concrete floor skeleton structure and a floor construction method.

[0004] The post-tensioned prestressed reinforced concrete floor skeleton structure has an overall "well" grid shape, and it includes:

[0005] Column caps, which are located at the four corners of the floor skeleton and are located at the upper ends of the structural columns arranged at the four corners;

[0006] Node molds, which are distributed at the cross-node positions of the grid structure;

[0007] Beam molds, whose two ends are connected to the node molds to form the "well" grid framework of the floor skeleton;

[0008] Plate molds, which are laid in the wells of the "well" grid framework formed by the beam molds and node molds, and the edges are connected and supported by the beam molds;

[0009] Steel bar meshes, which are laid on the node molds, plate molds, and beam molds as the skeleton of the cast-in-place reinforced concrete;

[0010] Steel strands, which are laid in the beam molds and the two ends are connected to the tensioning pedestal; the steel strands are post-tensioned prestressed steel strands.

[0011] Preferably, the node formwork, beam formwork and slab formwork are all precast formworks; the node formwork includes a middle node formwork in the middle area and side node formworks in the edge area, the beam formwork includes a middle beam formwork laid in the middle area and side beam formworks at the edges, and the node formwork is supported by vertical supports; the side beam formworks are laid between the column caps and side nodes on the same side and between side nodes, the middle beam formwork is laid between middle node formworks except at the edges, and both the side beam formworks and the middle beam formwork are arranged horizontally or longitudinally; the tensioning pedestal is arranged on the column caps at the four corners and on the side node formworks, and steel strands are laid horizontally and longitudinally where the grid beam formwork is located, and both ends of the steel strands are connected to the tensioning pedestals on the side node formworks at both ends and pass through all the beam formworks in this horizontal or longitudinal direction.

[0012] Preferably, the first steel bar socket is embedded in the node formwork, and the quantity and position of the first steel bar sockets are adapted to the quantity and position of the steel strands to be connected to this node. An assembly port for cooperating with the beam formwork is arranged on the node formwork, and the end of the beam formwork is inserted and placed on the node formwork through the assembly port.

[0013] Preferably, the beam formwork includes a trough structure as the main body. A horizontally arranged support wing structure is arranged on the upper edge of the trough. The slab formwork is laid on the support wing. A second steel bar socket is arranged at the bottom of the trough, and the steel strand passes through the second steel bar socket.

[0014] Preferably, the thickness of the slab formwork is 40mm - 80mm. The slab formwork is a precast reinforced concrete finished product, and a stiffening framework is arranged on the surface of the slab formwork.

[0015] Preferably, the stiffening framework is a steel bar framework formed by steel pipes filled with cement slurry inside. The stiffening framework protrudes from the surface of the slab formwork, and the steel bar mesh is laid on the stiffening framework.

[0016] Preferably, the column cap includes a bottom surface and a cross-shaped cantilever beam extending around the bottom surface. The cantilever beam is used to support the beam formwork. Reinforcement is arranged on the cantilever beam, and the reinforcement enters the trough of the beam formwork through the installation holes reserved on the bottom plate of the beam formwork; the side beam is a trough structure, additional steel bars spanning the column cap are arranged on the surface of the side beam, and / or a first steel bar cage is arranged inside the side beam.

[0017] Preferably, the elevation of the support wing of the beam formwork connected at the corner is lower than the elevation of other beam formworks.

[0018] Preferably, it further includes temporary vertical supports. A support cap for fitting and installing the middle node formwork and side node formworks is detachably installed at the end of the temporary vertical supports; a height adjusting device for adjusting the height of the support cap is arranged on the temporary vertical supports; or a stiffening frame is assembled on the temporary vertical supports, a stiffening rope and a rotary tensioner for adjusting the stiffening rope are connected to the stiffening frame, and a steel plate pedestal is arranged at the bottom of the temporary vertical supports.

[0019] A construction method for a prefabricated spliced bottom formwork to bear large load prestressed two-way concrete floor slabs, using the above-mentioned post-tensioned prestressed reinforced concrete floor slab skeleton structure; including prefabricated edge node forms, middle node forms, middle beam forms, edge beam forms, steel bar mesh groups, middle precast slab forms and corner precast slab forms; also including temporary vertical supports; the construction includes the following steps:

[0020] Step 1. Through planning and design, divide the construction area into a "well"-shaped grid, confirm each grid intersection point, and the grid intersection points include the corner points at the four corners, the intersection points of the horizontal and vertical lines on the edges, and the intersection points of the horizontal and vertical lines in the middle area;

[0021] Step 2. Lay the edge node forms and the middle node forms. There are cast-in-place structural reinforced concrete columns at the four corners, and column caps are provided at the upper ends of the structural columns. Temporary vertical supports are provided vertically at all the other intersection points. A supporting cap is installed at the upper end of the temporary vertical support. Then, first install the edge node forms and the middle node forms on each supporting cap;

[0022] Step 3. Lay the edge beam forms. The edge beam forms are laid horizontally and vertically. The edge node forms and the column caps support the edge beam forms to form a rectangular frame; lay the middle beam forms. The middle beam forms are laid horizontally and vertically, and both ends are placed on the middle node forms and the edge node forms; thus forming a beam form structure of a two-way grid pile;

[0023] Step 4. Lay the steel strands. Install tensioning pedestals in the edge node form area and the column cap area, and then lay the steel strands. The steel strands extend along the beam form grid formed by laying, that is, horizontally and vertically, and both ends are fixedly installed on the tensioning pedestals;

[0024] Step 5. Lay the slab forms. Install corner edge precast slab forms in the grids at the four corner positions, and place middle precast slab forms at the remaining positions. The four sides of the middle precast slab forms and the corner edge precast slab forms are all supported on the beam form edges forming the grid area;

[0025] Step 6. Lay the steel bar mesh. The steel bar mesh sheets adopt a preset steel bar mesh, and lay the corresponding steel bar meshes for the slab form area, the node form area and the beam form area;

[0026] Step 7. Pour the concrete surface layer. The concrete is poured on the steel bar mesh and fills the spaces in the beam forms and the node forms to form the concrete surface layer;

[0027] Step 8. Then tension the steel strands to apply prestress to complete the construction of the floor slab;

[0028] Step 9. Repeat the above steps for multi-layer construction as needed;

[0029] Or build using the following technical method,

[0030] Set up temporary vertical supports along the axis of the structural column grid to form the column cap of the side beam and the structural column by formwork pouring. The side beam is provided with ordinary reinforcement bars for bearing construction stage loads and post-tensioned prestressed steel strands for bearing the floor slab structure loads in the future. The two ends of the steel strands are connected to the steel pedestals on the sides of the structural columns; then, lay precast middle node forms by using temporary vertical supports at the intersection points of the divided longitudinal and transverse grid wells; lay middle beam forms longitudinally and transversely on the node forms, and one end close to the side beam is directly placed on the side beam to form the bottom form of the cross beam; then set up side forms along the edge of the side beam; then repeat steps four to eight above.

[0031] Compared with the prior art, the present solution has the following beneficial effects: This new reinforced concrete floor slab structure system uses precast reinforced concrete beam forms and slab forms to form a two-way grid structure, lays a standardized steel bar mesh, uses post-tensioned high-strength prestressed steel strands, etc., making the construction of the floor slab structure simple, fast, able to safely bear large floor slab loads, with low cost, and meeting the requirements of the currently highly advocated low-carbon energy-saving industrialized construction technology. This new floor slab structure can also be used to build an elevated ground floor. Brief Description of the Drawings

[0032] Figure 1 It is a schematic diagram of the overall structure of the device.

[0033] Figure 2 For Figure 1 It is a schematic diagram of the structure with the slab form removed.

[0034] Figure 3 It is a schematic diagram of the structure of the temporary support.

[0035] Figure 4 It is a schematic diagram of the structure of the node form.

[0036] Figure 5 It is a schematic sectional view of the beam form.

[0037] Figure 6 It is a schematic diagram of the structure of the slab form

[0038] Figure 7 It is a schematic diagram of the structure of the steel bar mesh.

[0039] Figure 8 It is a schematic diagram of the structure of the column cap.

[0040] Figure 9 It is a schematic cross-sectional view of the column cap.

[0041] Figure 10 It is a top view of the cooperation of components such as beam form units, node form units, and steel strands.

[0042] Figure 11 It is Figure 10 The sectional view of.

[0043] Figure 12 It is a schematic diagram of a tensioning pedestal.

[0044] Figure 13 It is a structural schematic diagram of a steel reinforcement cage.

[0045] Figure 14 It is a schematic diagram of the installation of a steel strand cross structure.

[0046] Figure 15 It is Figure 14 a cross-sectional view of

[0047] Figure 16 It is a structural schematic diagram of the construction method of Example 5.

[0048] Figure 17 It is a structural schematic diagram of a precast side beam form.

[0049] The technical names of the reference numerals in the figure are: 15 - vertical support, 1 - column cap, 2 - joint form, 2a - middle joint form, 2b - side joint form, 2c - assembly opening, 4 - beam form, 4a - middle beam form, 4b - side beam form, 4c - support wing, 8 - tensioning pedestal, 10 - slab form, 11 - corner side precast slab form, 12 - steel bar mesh, 6 - steel strand, 16 - support cap, 17 - height adjusting device, 18 - stiffening frame, 19 - stiffening rope, 20 - tensioner, 21 - steel plate pedestal, 22 - steel bar sleeve buckle, 24 - stiffening framework, 25 - steel reinforcement cage, 26 - cantilever beam, 27 - reinforcement, 28 - additional steel bars, 28 - side beam. Specific embodiments

[0050] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0051] Example 1

[0052] The post-tensioned prestressed reinforced concrete floor slab framework structure, the overall floor slab framework structure is in a "well" grid shape, and it includes:

[0053] Column cap 1, column cap 1 is located at the four corners of the floor slab framework, and column cap 1 is located at the upper end of the structural columns arranged at the four corners; wherein the position where column cap 1 is located is on the cast-in-place structural column, and it plays a role of a stable support column;

[0054] Joint form 2, joint form 2 is distributed at the cross-joint positions of the grid structure; the joint form 2 is a precast form made of reinforced concrete, and the size and shape of the joint form 2 are designed according to the position and function; its main purpose is to support the beam form 4, so as to form a vertical and horizontal framework structure;

[0055] The beam formwork 4 has its two ends connected to the joint formwork 2, forming a "well" grid framework of the floor slab skeleton; the side of the beam formwork 4 can be used for erecting the slab formwork 10. Among them, the beam formwork 4b is a straight beam formwork 4 in this embodiment. The straight beam formwork 4 is of a trough structure, and a flying wing is provided on the upper side of the beam formwork 4 to support the slab formwork 10.

[0056] The slab formwork 10 is laid in the well grid formed by the beam formwork 4 and the joint formwork 2, and its edge is connected to and supported by the beam formwork 4; the slab formwork 10, the beam formwork 4, and the joint formwork 2 thus form the bottom surface structure of the overall skeleton.

[0057] The steel bar mesh 12 is laid on the joint formwork 2, the slab formwork 10, and the beam formwork 4 as the skeleton of the post-cast reinforced concrete; the laying of the steel bar mesh 12 is carried out using standard steel bar mesh sheets, which greatly improves the laying efficiency. Moreover, the standardized design can also save costs. After laying the steel bar mesh 12, the slab surface can be poured.

[0058] The steel strand 6 is laid in the beam formwork 4 and its two ends are connected to the tensioning pedestal 8; the steel strand 6 is a post-tensioned prestressed steel strand. Of course, during the construction of this kind of skeleton, temporary vertical supports 15 need to be set at the intersection points. The temporary vertical supports 15 are used to support the joint formwork 2 at the joint formwork 2 position, and the positions of each node of the temporary vertical support 15 are confirmed through prior planning of the grid. Among them, the steel strand 6 is initially installed before laying the steel bar mesh 12.

[0059] The joint formwork 2, the beam formwork 4, and the slab formwork 10 are all precast forms, specifically reinforced concrete precast forms; the joint formwork 2 includes the middle joint formwork 2a in the middle area and the edge joint formwork 2b in the edge area. The beam formwork 4 includes the middle beam formwork 4b laid in the middle area and the edge beam formwork 4b at the edge. The joint formwork 2 is supported by the vertical support 15; the edge beam formwork 4b is laid between the column cap 1 on the same side and the edge joint, and between the edge joints. The middle beam formwork 4b is laid between the middle joint formwork 2a except for the edge part. The edge beam formwork 4b and the middle beam formwork 4b are both arranged horizontally or longitudinally; the tensioning pedestal 8 is set on the column caps 1 at the four corners and on the edge joint formwork 2b. The steel strand 6 is laid horizontally and longitudinally in the well grid beam formwork 4, and the two ends of the steel strand 6 are connected to the tensioning pedestal 8 on the two end edge joint formwork 2b and pass through all the beam formworks 4 in this horizontal or longitudinal direction. Among them, fine steel bars are arranged inside the beam formwork 4b to bear the construction load of the precast slab formwork 10 placed on it and the cast-in-place concrete floor slab. Generally, the pre-tensioned long-line method is used for production. The beam formwork 4b is embedded with a steel bar socket 22 at the trough bottom for buckling the passing steel strand 6 and the lifting hook during the construction stage.

[0060] A first steel bar socket 22 is embedded in the node mold 2a. The quantity and positions of the first steel bar sockets 22 are adapted to the quantity and positions of the steel strands 6 to be connected to the node. An assembly opening 2c for cooperating with the beam mold 4 is arranged on the node mold 2. The end of the beam mold 4 is inserted and placed on the node mold 2 through the assembly opening 2c.

[0061] The described beam mold 4 includes a main body groove structure. A horizontally arranged support wing 4c structure is arranged on the upper edge of the groove body. The formwork 10 is placed on the support wing 4c. A second steel bar socket 23 is arranged at the bottom of the groove body. The steel strand 6 passes through the second steel bar socket 23.

[0062] In this embodiment, the thickness of the formwork 10 is 40 mm to 80 mm. The formwork 10 is a precast reinforced concrete finished product. A stiffening framework 24 is arranged on the surface of the formwork 10. The stiffening framework 24 is a framework made of steel bars. The formwork 10 includes a formwork 10 in the middle area and a corner edge precast formwork 11 at the corner. Both the formwork 10 and the corner edge precast formwork 11 are finished products of precast reinforced concrete structures. The described stiffening framework is used not only to increase the stiffness of the formwork 10 but also as a support for the steel bar mesh 12. The stiffening framework 24 is a steel bar framework formed by steel pipes filled with cement slurry inside. The stiffening framework 24 protrudes from the surface of the formwork 10. The steel bar mesh 12 is laid on the stiffening framework 24.

[0063] For the convenience of understanding, the column cap 1 is further explained. The column cap 1 includes a bottom surface and a "cross"-shaped cantilever beam 26 extending from the bottom surface to the surroundings. The cantilever beam 26 is used to support the beam mold 4. Reinforcement bars 27 are arranged on the cantilever beam 26. The reinforcement bars 27 enter the groove of the beam mold 4 through the installation holes reserved on the bottom plate of the beam mold 4; the side beam 28 is a groove structure. Additional reinforcement bars 28 spanning the column cap 1 are arranged on the surface of the side beam 28, and / or a first steel bar cage 25 is arranged inside the side beam 28.

[0064] In this embodiment, a supporting cap 16 for fitting and installing the middle node mold 2a and the side node mold 2b is detachably installed at the end of the temporary vertical support 15; a height adjusting device 17 for adjusting the height of the supporting cap 16 is arranged on the temporary vertical support 15; or a stiffening frame 18 is assembled on the temporary vertical support 15. A stiffening rope 19 and a rotary tensioner 20 for adjusting the stiffening are connected to the stiffening frame 18. A steel plate pedestal 21 is arranged at the bottom of the temporary vertical support 15.

[0065] Embodiment 2

[0066] On the basis of Embodiment 1, in order to better enhance the punching shear strength of the corner area of the floor slab structure, when the load on the floor slab and the column grid size are large, the precast beam formwork 4 around the corner grid is simply improved, and one side of the support formwork 10 sinks, so that the surface elevation of the corner precast slab formwork 11 drops. After pouring the floor slab in this way, the local thickness of the grid floor slab increases, achieving the purpose of enhancing the overall stiffness and punching shear strength of the floor slab structure. That is, the elevation of the support wing 4c of the beam formwork 4 connected to the corner is lower than that of other beam formworks 4.

[0067] Embodiment 3

[0068] A construction method for a precast spliced bottom formwork to bear a large load prestressed two-way concrete floor slab, adopting the above-mentioned post-tensioned prestressed reinforced concrete floor slab skeleton structure, and the skeleton is the structural skeleton described in Embodiment 1; it includes precast side node formworks 2b, middle node formworks 2a, middle beam formworks 4b, side beam formworks 4b, 12 groups of steel bar meshes, middle precast slab formworks 10 and corner precast slab formworks 10; it also includes temporary vertical supports 15; the construction includes the following steps:

[0069] Step 1: Divide the construction area into "well"-shaped grids through planning and design, and confirm each grid intersection point. The grid intersection points include the corner points at the four corners, the intersection points of the horizontal and vertical lines on the side, and the intersection points of the horizontal and vertical lines in the middle area;

[0070] Step 2: Lay the side node formworks 2b and the middle node formworks 2a. There are cast-in-place structural reinforced concrete columns at the four corners. Column caps 1 are provided at the upper ends of the structural columns. Temporary vertical supports 15 are provided at all other intersection points. A support cap 16 is installed at the upper end of the temporary vertical support 15. Then, first install the side node formworks 2b and the middle node formworks 2a on each support cap 16;

[0071] Step 3: Lay the side beam formworks 4b. The side beam formworks 4b are laid horizontally and longitudinally. The side node formworks 2b and the column caps 1 support the side beam formworks 4b to form a rectangular frame; lay the middle beam formworks 4b. The middle beam formworks 4b are laid horizontally and longitudinally, and both ends are placed on the middle node formworks 2a and the side node formworks 2b; thus, a beam formwork 4 structure of a two-way grid pile is formed;

[0072] Step 4: Lay the steel strands 6. Install the tensioning pedestals 8 in the side node formwork 2b area and the column cap 1 area, and then lay the steel strands 6. The steel strands 6 extend along the grids of the laid beam formworks 4, that is, horizontally and longitudinally, and both ends are fixedly installed on the tensioning pedestals 8;

[0073] Step 5: Lay the formwork 10. Install the corner edge precast slab formworks 11 in the grids at the four corners, and place the middle precast slab formworks 10 at the remaining positions. The four sides of the middle precast slab formworks 10 and the corner edge precast slab formworks 11 are all supported on the edges of the beam formworks 4 forming the grid area;

[0074] Step Six: Lay the steel mesh 12. The steel mesh 12 sheets adopt a preset steel mesh 12, and lay the corresponding steel mesh 12 for the slab form 10 area, the joint form 2 area, and the beam form 4 area.

[0075] Step Seven: Pour the concrete surface layer. The concrete is poured on the steel mesh 12 and fills the spaces inside the beam form 4 and the joint form 2 to form the concrete surface layer.

[0076] Step Eight: Then tension the steel strands 6 to apply prestress to complete the construction of the floor slab.

[0077] Embodiment 4

[0078] On the basis of Embodiment 3, when the floor is a multi-story structure, repeat the above steps as needed for multi-story construction.

[0079] Embodiment 5

[0080] On the basis of Embodiments 3 and 4, the following improvements are made. Set up temporary vertical supports 15 along the axis of the structural column grid to formwork and pour the side beam 28 and the column cap 1 of the structural column. The side beam 28 is provided with ordinary reinforcement 27 for bearing the construction stage load and post-tensioned prestressed steel strands 6 for bearing the floor slab structure load in the future. The two ends of the steel strands 6 are connected to the steel pedestals on the side of the structural column. Then use temporary vertical supports 15 to lay precast intermediate joint forms 2a at the intersection points of the divided vertical and horizontal grid cells. Horizontally and vertically lay intermediate beam forms 4b on the joint form 2. One end close to the side beam 28 is directly placed on the side beam 28 to form the bottom form of the cross beam. Then set up side forms along the edge of the side beam 28. Then repeat Steps Four to Eight above.

[0081] The side beam 28 along the four sides of the structural column grid is a composite beam cast in two times. The cross-section method and reinforcement 27 of the first casting satisfy bearing the construction load and self-weight transmitted from the middle as a support beam. After the floor slab is poured, an upper and lower composite beam is formed, and the tensioned embedded steel strands 7 bear the load in the service stage of the floor slab structure. The method of the steel pedestal 9 is the same as above, and it can not pass through or pass through the column. Generally, the latter is recommended. Reinforcement bars 33 and stirrups 34 are arranged on the upper part of the composite beam 30.

Claims

1. Post-tensioned prestressed reinforced concrete floor skeleton structure, characterized in that: The overall floor slab skeleton structure is in a "grid" network shape, and it includes: Column caps (1), which are located at the four corners of the floor slab skeleton and are located at the upper ends of the structural columns arranged at the four corners; Node molds (2), which are distributed at the cross-node positions of the network structure; Beam molds (4), the two ends of which are connected to the node molds (2) to form a "grid" framework of the floor slab skeleton; Slab molds (10), which are laid in the grids formed by the beam molds (4) and node molds (2), and the edges are connected and supported by the beam molds (4); Steel bar meshes (12), which are laid on the node molds (2), slab molds (10) and beam molds (4) as the skeleton of the post-cast reinforced concrete; Steel strands (6), which are laid in the beam molds (4) and the two ends are connected to the tensioning pedestals (8); the steel strands (6) are post-tensioned prestressed steel strands (6).

2. The post-tensioned prestressed reinforced concrete floor skeleton structure according to claim 1, characterized in that: The node molds (2), beam molds (4) and slab molds (10) are all precast molds; the node molds (2) include middle node molds (2a) in the middle area and edge node molds (2b) in the edge area, the beam molds (4) include middle beam molds (4b) laid in the middle area and edge beam molds (4b) at the edges, the node molds (2) are supported by vertical supports (15); the edge beam molds (4b) are laid between the column caps (1) and edge nodes on the same side, between edge nodes and edge nodes, the middle beam molds (4b) are laid between the middle node molds (2a) except at the edges, the edge beam molds (4b) and middle beam molds (4b) are arranged horizontally or longitudinally; the tensioning pedestals (8) are arranged on the column caps (1) at the four corners and on the edge node molds (2b), the steel strands (6) are laid horizontally and longitudinally where the grid network beam molds (4) are located, and the two ends of the steel strands (6) are connected to the tensioning pedestals (8) on the two end edge node molds (2b) and pass through all the beam molds (4) in this horizontal or longitudinal direction.

3. The post-tensioned prestressed reinforced concrete floor skeleton structure according to claim 1, characterized in that: First steel bar socket buttons (22) are embedded on the node molds (2), and the quantity and positions of the first steel bar socket buttons (22) are adapted to the quantity and positions of the steel strands (6) to be connected at this node. Assembly openings (2c) for cooperating with the beam molds (4) are arranged on the node molds (2), and the ends of the beam molds (4) are inserted and placed on the node molds (2) through the assembly openings (2c).

4. The post-tensioned prestressed reinforced concrete floor slab skeleton structure according to claim 1, characterized in that: The beam molds (4) include a main trough structure. A horizontally arranged support wing (4c) structure is arranged on the upper edge of the trough. The slab molds (10) are placed on the support wings (4c). Second steel bar socket buttons (23) are arranged at the bottom of the trough, and the steel strands (6) pass through the second steel bar socket buttons (23).

5. The post-tensioned prestressed reinforced concrete floor skeleton structure according to claim 1, characterized in that: The thickness of the slab molds (10) is 40 mm to 80 mm. The slab molds (10) are precast reinforced concrete finished products, and stiffening frameworks (24) are arranged on the surfaces of the slab molds (10).

6. The post-tensioned prestressed reinforced concrete floor skeleton structure according to claim 5, characterized in that: The stiffening frameworks (24) are steel bar frameworks formed by steel pipes filled with cement slurry inside. The stiffening frameworks (24) protrude from the surfaces of the slab molds (10), and the steel bar meshes (12) are laid on the stiffening frameworks (24).

7. The post-tensioned prestressed reinforced concrete floor slab skeleton structure according to claim 1, wherein: The column cap (1) includes a bottom surface and a "cross"-shaped cantilever beam (26) extending around the bottom surface. The cantilever beam (26) is used to support the beam formwork (4). Reinforcement bars (27) are arranged on the cantilever beam (26), and the reinforcement bars (27) enter the groove of the beam formwork (4) through the installation holes reserved on the bottom plate of the beam formwork (4); the side beam (28) is a groove-shaped structure, additional steel bars (28) spanning the column cap (1) are arranged on the surface of the side beam (28), and / or a first steel bar cage (25) is arranged inside the side beam (28).

8. The post-tensioned prestressed reinforced concrete floor skeleton structure according to claim 4, characterized in that: The elevation of the support wing (4c) of the beam formwork (4) connected to the corner is lower than the elevation of other beam formworks (4).

9. The post-tensioned prestressed reinforced concrete floor skeleton structure according to claim 2, characterized in that: It also includes a temporary vertical support (15). A supporting cap (16) for fitting and installing the middle node formwork (2a) and the side node formwork (2b) is detachably installed at the end of the temporary vertical support (15); a height adjusting device (17) for adjusting the height of the supporting cap (16) is arranged on the temporary vertical support (15); or a stiffening frame (18) is assembled on the temporary vertical support (15), a stiffening rope (19) and a rotary tensioner (20) for adjusting the stiffening are connected to the stiffening frame (18), and a steel plate pedestal (21) is arranged at the bottom of the temporary vertical support (15).

10. A construction method for a prefabricated spliced bottom formwork to bear a large load of prestressed two-way concrete floor slabs, characterized in that: Adopt the post-tensioned prestressed reinforced concrete floor skeleton structure described in any one of claims 1 to 9; include prefabricated side node formwork (2b), middle node formwork (2a), middle beam formwork (4b), side beam formwork (4b), steel bar mesh (12) group, middle precast slab formwork (10) and corner precast slab formwork (10); also include a temporary vertical support (15); the construction includes the following steps: Step 1: Through planning and design, divide the area to be constructed into a "well"-shaped grid, confirm each grid intersection point, and the grid intersection points include the corner points at the four corners, the intersection points of the horizontal and vertical lines on the sides, and the intersection points of the horizontal and vertical lines in the middle area; Step 2: Lay the side node formwork (2b) and the middle node formwork (2a). There are cast-in-place structural reinforced concrete columns at the four corners. Column caps (1) are arranged at the upper ends of the structural columns. Temporary vertical supports (15) are arranged vertically at all the remaining intersection points. Supporting caps (16) are installed at the upper ends of the temporary vertical supports (15). Then, first install the side node formwork (2b) and the middle node formwork (2a) on each supporting cap (16); Step 3: Lay the side beam formwork (4b). The side beam formwork (4b) is laid horizontally and longitudinally. The side node formwork (2b) and the column cap (1) support the side beam formwork (4b) to form a rectangular frame; lay the middle beam formwork (4b). The middle beam formwork (4b) is laid horizontally and longitudinally, and its two ends are placed on the middle node formwork (2a) and the side node formwork (2b); thus, a beam formwork (4) structure of a two-way grid pile is formed; Step 4: Lay the steel strands (6). Install tensioning pedestals (8) in the area of the side node formwork (2b) and the area of the column cap (1), and then lay the steel strands (6). The steel strands (6) extend along the grid of the laid beam formwork (4), that is, horizontally and longitudinally, and are fixedly installed at both ends on the tensioning pedestals (8); Step Five: Lay the slab formwork (10). Install the corner-edge precast slab formwork (11) at the four corners of the grid, and place the middle precast slab formwork (10) at the remaining positions. The four sides of the middle precast slab formwork (10) and the corner-edge precast slab formwork (11) are all supported on the edges of the beam formwork (4) that forms the grid area. Step Six: Lay the steel mesh (12). The steel mesh (12) sheets are of a preset steel mesh (12). Lay the corresponding steel mesh (12) for the slab formwork (10) area, the node formwork (2) area, and the beam formwork (4) area. Step Seven: Pour the concrete surface layer. The concrete is poured on the steel mesh (12) and fills the spaces inside the beam formwork (4) and the node formwork (2) to form the concrete surface layer. Step Eight: Then tension the steel strands (6) to apply prestress to complete the construction of the floor slab. Step Nine: Repeat the above steps for multi-story construction as needed. Or construct using the following technical method. Set up temporary vertical supports (15) along the axis of the structural column grid to formwork and pour the side beam (28) and the column cap (1) of the structural column. The side beam (28) is provided with ordinary reinforcement (27) to bear the construction stage load and post-tensioned steel strands (6) to bear the future floor slab structure load. The two ends of the steel strands (6) are connected to the steel pedestals on the sides of the structural column. Then, use the temporary vertical supports (15) to lay the precast middle node formwork (2a) at the intersection points of the divided vertical and horizontal grids. Horizontally and vertically lay the middle beam formwork (4b) on the node formwork (2). One end close to the side beam (28) is directly placed on the side beam (28) to form the bottom formwork of the cross beam. Then, set up the side form along the edge of the side beam (28). Then, repeat Steps Four to Eight above.

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