Reinforced concrete slab column connecting joint

Abstract

The invention discloses a reinforced concrete plate column connecting joint, which relates to the technical field of constructional engineering and comprises a concrete column, a concrete plate and a joint device, the joint device comprises a middle steel pipe and a plurality of pieces of cross-shaped steel. The cross-shaped steel is fixedly arranged on the circumferential outer side wall of the middle steel pipe around the axis of the middle steel pipe, and the cross-shaped steel is located at the same height in the vertical axis direction of the middle steel pipe. The upper end and the lower end of the middle steel pipe are located in a reinforcement cage of the concrete column. The parts, provided with the cross-shaped steel, of the middle steel pipe are all located in a reinforcement cage of the concrete slab; the cross-shaped steel is formed by fixedly connecting two web plates in a crossed mode, and acute angles are formed between the web plates of the cross-shaped steel and the upper surface of the concrete slab. Through the arrangement, the punching resistance is improved, and the integrity of the plate-column joint is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of construction engineering, and particularly to a reinforced concrete slab-column connection node. Background Art

[0002] With the development of modern architecture, people urgently need comfortable spaces to meet visual aesthetics, building functions, etc. Therefore, the flat slab floor system has emerged as the times require. As a type of flat slab floor system, the slab-column structure has good integrity and an open building space. However, when such a structure is subjected to strong earthquake actions, the additional stress caused by the unbalanced moment will produce a magnification effect around the column. When the shear stress is too large and there is a lack of effective shear resistance measures, punching failure is very likely to occur at the slab-column joint, and even lead to the continuous collapse of the structure.

[0003] Therefore, it is particularly important to provide a reinforced concrete slab-column connection node to improve the punching shear resistance performance at the connection node. Summary of the Invention

[0004] The purpose of the present invention is to provide a reinforced concrete slab-column connection node to solve the problems existing in the above-mentioned prior art, improve the punching shear resistance performance, and enhance the integrity of the slab-column joint.

[0005] To achieve the above object, the present invention provides the following solution:

[0006] The present invention provides a reinforced concrete slab-column connection node, including a concrete column, a concrete slab, and a node device; the node device includes a central steel pipe and a plurality of cross-shaped steel bars; each of the cross-shaped steel bars is fixedly arranged on the circumferential outer wall of the central steel pipe around the axis of the central steel pipe, and each of the cross-shaped steel bars is located at the same height in the vertical axis direction of the central steel pipe; the upper end and the lower end of the central steel pipe are both located inside the steel cage of the concrete column; a part of each of the cross-shaped steel bars of the central steel pipe is located inside the steel cage of the concrete slab; the cross-shaped steel bar is formed by fixedly connecting two webs in a cross shape, and each web of the cross-shaped steel bar and the upper surface of the concrete slab are both acute angles.

[0007] Preferably, in the vertical axis direction of the central steel pipe, the upper end of each of the cross-shaped steel bars is fixedly connected to the outer wall of the central steel pipe above the cross-shaped steel bar through at least one upper flange; and the lower end of each of the cross-shaped steel bars is fixedly connected to the outer wall of the central steel pipe below the cross-shaped steel bar through at least one lower flange; and in the vertical axis direction of the central steel pipe, the upper end of each upper flange and the lower end of each lower flange are both located inside the concrete column.

[0008] Preferably, connecting columns are fixedly arranged on each of the upper flanges and each of the lower flanges located within the concrete slab; in the vertical axis direction of the middle steel pipe, the upper ends of the connecting columns on the upper flange protrude above the upper plane of the upper flange; and the lower ends of the connecting columns on the lower flange all protrude below the lower plane of the lower flange.

[0009] Preferably, the concrete column includes an upper outer sleeve and a lower outer sleeve; the steel reinforcement cage of the concrete column is located within the upper outer sleeve and the lower outer sleeve, and the concrete column is formed by pouring concrete; in the vertical axis direction of the middle steel pipe, the upper outer sleeve is sleeved on the middle steel pipe above each cross-shaped steel; and the lower outer sleeve is sleeved on the middle steel pipe below each cross-shaped steel; and the distance between the lower end of the upper outer sleeve and the upper surface of the concrete slab, as well as the distance between the upper end of the lower outer sleeve and the lower surface of the concrete slab, are both 0.5 cm to 1 cm.

[0010] Preferably, each cross-shaped steel is circumferentially and evenly distributed around the vertical axis of the middle steel pipe; adjacent two cross-shaped steels are fixedly connected together through a ring plate assembly.

[0011] Preferably, the inner diameter of the ring plate assembly is smaller than the outer diameter of the concrete column; and the outer diameter of the ring plate assembly is larger than the outer diameter of the concrete column.

[0012] Preferably, the widths of the upper flange and the lower flange on the cross-shaped steel gradually increase from the end far from the middle steel pipe to the end close to the middle steel pipe.

[0013] Preferably, non-node stirrups are arranged within the concrete column, the non-node stirrups are located within the concrete column and on the outer side of the column longitudinal bars of the steel reinforcement cage of the concrete column away from the axis of the concrete column, and the non-node stirrups are fixedly connected to the column longitudinal bars of the steel reinforcement cage of the concrete column; node area stirrups are arranged on the outer side of the middle steel pipe away from its axis, and the node area stirrups are fixedly connected to the column longitudinal bars of the steel reinforcement cage of the concrete column.

[0014] Preferably, the ring plate assembly includes an upper ring plate and a lower ring plate; in the vertical axis direction of the middle steel pipe, the upper ring plate is arranged parallel above the lower ring plate; and a plurality of stiffening ribs are also fixedly connected between the upper ring plate and the lower ring plate, and each stiffening rib is perpendicularly arranged with respect to the upper ring plate and the lower ring plate respectively.

[0015] Preferably, on the vertical axis direction of the middle steel pipe, extension side plates are fixedly arranged at both the upper end and the lower end of the web, and the extension side plates are fixedly connected to the corresponding parts of the corresponding upper flange or lower flange.

[0016] The present invention has achieved the following technical effects compared with the prior art:

[0017] For the reinforced concrete slab-column connection joint provided by the present invention, by arranging the cross-shaped steel placed obliquely on the middle steel pipe, when punching load acts, stress usually concentrates on certain parts. After the cross-shaped steel placed obliquely undergoes minor buckling, it can change the stress transmission path, disperse the originally concentrated stress to a larger area. This is because the buckled cross-shaped steel is like an elastic "buffer", which can transfer the local high stress to the surrounding concrete through its own deformation, avoiding excessive local stress concentration. For example, when a certain corner of the joint bears a large punching force, the buckling of the cross-shaped steel can transfer this part of the stress to the surrounding concrete and the steel in other parts, making the stress distribution of the entire joint more uniform; by improving the stress transmission path, the cross-shaped steel and concrete can cooperate better in bearing force. Under normal circumstances, the cross-shaped steel and concrete each bear a part of the load, but due to the different material properties and force-bearing characteristics, their cooperation is not ideal. However, the minor buckling of the cross-shaped steel enables the stress to be transmitted more smoothly between the two, enabling them to reasonably share the load according to their respective mechanical properties, improving the ability of the entire joint to resist punching load, and thus enhancing the integrity of the slab-column joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of the overall structure of the reinforced concrete slab-column connection joint provided by the present invention;

[0020] Figure 2 It is a schematic diagram of the structure of the joint device in the reinforced concrete slab-column connection joint provided by the present invention from the first perspective;

[0021] Figure 3 It is a schematic diagram of the structure of the joint device in the reinforced concrete slab-column connection joint provided by the present invention from the second perspective;

[0022] Figure 4 It is a top view of the reinforced concrete slab-column connection joint provided by the present invention in the state before pouring concrete.

[0023] In the figure:

[0024] 10 - Node device; 11 - Middle steel pipe; 12 - Cross - shaped steel; 121 - Web; 122 - Extended side plate; 13 - Upper flange; 14 - Lower flange; 15 - Steel bolt; 16 - Upper ring plate; 17 - Lower ring plate; 18 - Stiffener

[0025] 20 - Concrete column; 21 - Upper outer sleeve; 22 - Lower outer sleeve; 23 - Column longitudinal reinforcement

[0026] 30 - Concrete slab Specific implementation manner

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention

[0028] The purpose of the present invention is to provide a reinforced concrete slab - column connection node to solve the problems existing in the prior art, improve the punching shear resistance, and enhance the integrity of the slab - column node

[0029] To make the above - mentioned objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners

[0030] Embodiment 1

[0031] This embodiment provides a reinforced concrete slab - column connection node, as Figures 1 to 4 shown, including a concrete column 20, a concrete slab 30, and a node device 10; the node device 10 includes a middle steel pipe 11 and a plurality of cross - shaped steels 12; each cross - shaped steel 12 is fixedly arranged on the circumferential outer wall of the middle steel pipe 11 around the axis of the middle steel pipe 11, and each cross - shaped steel 12 is at the same height in the vertical axis direction of the middle steel pipe 11; the upper end and the lower end of the middle steel pipe 11 are both located inside the steel cage of the concrete column 20; the part of the middle steel pipe 11 with each cross - shaped steel 12 is located inside the steel cage of the concrete slab 30; the cross - shaped steel 12 is formed by fixedly connecting two webs 121 in a cross - shape, and each web 121 of the cross - shaped steel 12 forms an acute angle with the upper surface of the concrete slab 30

[0032] Specifically, the node device 10 is in the poured concrete of the concrete column 20 and the concrete slab 30

[0033] By adopting the cross-shaped steel 12 placed obliquely on the middle steel pipe 11, when punching load acts, stress usually concentrates on certain parts. After the cross-shaped steel 12 placed obliquely undergoes minor buckling, it can change the stress transmission path and disperse the originally concentrated stress to a larger area. This is because the buckled cross-shaped steel 12 is like an elastic "buffer", which can transfer the local high stress to the surrounding concrete through its own deformation, avoiding excessive stress concentration in a local area. For example, when a large punching force is borne at a certain corner of the joint, the buckling of the cross-shaped steel 12 can transfer this part of the stress to the surrounding concrete and the steel shapes in other parts, making the stress distribution of the entire joint more uniform; by improving the stress transmission path, the cross-shaped steel 12 and the concrete can work together better. Under normal circumstances, the cross-shaped steel 12 and the concrete each bear a part of the load, but due to the different material properties and stress characteristics, their cooperation is not ideal. However, the minor buckling of the cross-shaped steel 12 enables stress to be transmitted more smoothly between the two, enabling them to share the load reasonably according to their respective mechanical properties, improving the ability of the entire joint to resist punching load, and thus enhancing the integrity of the slab-column joint.

[0034] Specifically, multiple cross-shaped steels 12 are arranged around the circumferential outer wall of the middle steel pipe 11, and the cross-shaped steel 12 is fixedly connected by two webs 121 in a cross shape. This structure can effectively increase the flexural section modulus at the joint. When the concrete slab 30 is subjected to a bending moment, each web 121 of the cross-shaped steel 12 can bear large tensile stress and compressive stress, thereby improving the flexural capacity of the joint and reducing the deformation and cracking of the concrete slab 30 at the joint; the acute angle setting enables the webs 121 of the cross-shaped steel 12 to more effectively resist shear force, disperse the shear force into the middle steel pipe 11 and the concrete column 20, avoid shear failure at the joint, and improve the shear resistance performance of the joint; the middle steel pipe 11 and the cross-shaped steel 12 of the joint device 10 are located inside the steel reinforcement cages of the concrete column 20 and the concrete slab 30. After concrete pouring, good bonding is formed between the steel shapes and the concrete. The special arrangement and angle setting of the cross-shaped steel 12 enable it to work better with the surrounding concrete when stressed. For example, under the action of load, the deformation of the cross-shaped steel 12 will drive the surrounding concrete to deform together, and the concrete also plays a restraining role on the cross-shaped steel 12. The two interact with each other and jointly bear the load, improving the overall performance of the joint.

[0035] Among them, the relevant setting description of the joint device 10:

[0036] Specifically, the length of the middle steel pipe 11 (or the height in the vertical axis direction of the concrete column 20) should be greater than 1.5 times the thickness of the concrete slab 30.

[0037] In the optional scheme of this embodiment, preferably, such asFigures 1 to 4 As shown, in the vertical axis direction of the middle steel pipe 11, the upper ends of the cross-shaped steel bars 12 are fixedly connected to the outer wall of the middle steel pipe 11 above the cross-shaped steel bar 12 through at least one upper flange 13; and the lower ends of the cross-shaped steel bars 12 are fixedly connected to the outer wall of the middle steel pipe 11 below the cross-shaped steel bar 12 through at least one lower flange 14; and in the vertical axis direction of the middle steel pipe 11, the upper ends of the upper flanges 13 and the lower ends of the lower flanges 14 are both located within the concrete column 20. By arranging the upper and lower flanges 14 in the vertical axis direction of the middle steel pipe 11, the cross-shaped steel bar 12 and the middle steel pipe 11 form a more stable overall structure. The existence of the flanges increases the cross-sectional dimension and moment of inertia at the joint, improves the bending and torsional resistance of the joint in the horizontal and vertical directions, reduces the deformation and displacement of the cross-shaped steel bar 12 and the middle steel pipe 11 when stressed, enhances the stability of the entire joint, and can better withstand various complex load effects; the setting of the upper and lower flanges 14 makes the force transfer between the cross-shaped steel bar 12, the middle steel pipe 11 and the concrete column 20 more balanced.

[0038] Specifically, one upper flange 13 is fixedly arranged at the upper ends of the two webs 121 of the cross-shaped steel bar 12 respectively, and one lower flange 14 is fixedly arranged at the lower ends of the two webs 121 of the cross-shaped steel bar 12 respectively. The ends of the upper flange 13 and the lower flange 14 close to the middle steel pipe 11 are bent and attached to the corresponding outer wall of the middle steel pipe 11. Adopting the bending structure can enhance the seismic performance of the joint.

[0039] In an alternative embodiment of the present embodiment, preferably, as Figures 1 to 3 shown, connecting columns are fixedly arranged on each of the upper flanges 13 and each of the lower flanges 14 located within the concrete slab 30; in the vertical axis direction of the middle steel pipe 11, the upper ends of the connecting columns on the upper flange 13 protrude from the upper plane of the upper flange 13; and the lower ends of the connecting columns on the lower flange 14 all protrude from the lower plane of the lower flange 14. The connecting columns protruding from the flange plane increase the biting area and frictional force between the flange and the concrete slab 30. When the concrete slab 30 bears horizontal shear force, the connecting columns can effectively prevent the relative sliding between the flange and the concrete slab 30 and bear a part of the shear force, thereby improving the shear resistance of the joint.

[0040] Specifically, the connecting column is a steel bolt 15, and a plurality of through holes are formed in the upper flange 13 and the lower flange 14, and the steel bolt 15 is fixedly penetrated through the corresponding through holes; the bonding effect between the joint device 10 and the concrete is enhanced, making the joint have excellent integrity.

[0041] In an alternative embodiment of the present embodiment, preferably, as Figure 2 and Figure 3As shown, in the vertical axis direction of the middle steel pipe 11, extension side plates 122 are fixedly arranged at both the upper end and the lower end of the web 121. The extension side plates 122 are fixedly connected to the corresponding parts of the corresponding upper flange 13 or lower flange 14. The extension side plates 122 increase the connection area between the cross-shaped steel 12 and the upper and lower flanges 14, making the force transmission more uniform when the joint bears bending moment, effectively reducing the stress concentration phenomenon at the connection, thereby improving the bending resistance of the joint and enhancing the stability of the structure; the extension side plates 122 expand the force transmission area, enabling the load borne by the web 121 to be more effectively transmitted to the upper and lower flanges 14, and then transmitted to the middle steel pipe 11 and the concrete column 20 through the flanges. This effect of dispersing the load can avoid excessive concentration of the load in a local area, improve the bearing capacity of the joint, and enable the structure to bear external forces more evenly.

[0042] Specifically, when the axis of the middle steel pipe 11 is parallel or coincident with the axis of the concrete column 20, the web 121 of the cross-shaped steel 12 is a straight plate, and its central symmetry plane is placed at 45° with respect to the column cross-section of the concrete column 20 (that is, the cross-section formed after the concrete column 20 is cut by a horizontal plane when the axis of the concrete column 20 is in a vertical state). The extension side plates 122 arranged at the upper end and the lower end of the web 121 extend away from the web 121 along the direction of the column cross-section of the concrete column 20.

[0043] In an alternative solution of this embodiment, preferably, as Figure 2 and Figure 3 shown, the cross-shaped steels 12 are circumferentially and evenly distributed around the vertical axis of the middle steel pipe 11; adjacent two cross-shaped steels 12 are fixedly connected together through a ring plate assembly. The uniform distribution of the cross-shaped steels 12 makes the force on the slab-column connection joint more balanced in all directions. When the concrete slab 30 bears the load, the force can be evenly transmitted to the middle steel pipe 11 and the concrete column 20 through the uniformly distributed cross-shaped steels 12, avoiding the situation of excessive local stress caused by uneven distribution of the cross-shaped steels 12, and improving the bearing capacity and stability of the joint; the uniformly distributed cross-shaped steels 12 and the ring plate assembly together form a space truss structure, enhancing the overall stiffness and integrity of the joint. Under the action of the load, each cross-shaped steel 12 and the ring plate assembly can work together to jointly bear the external force, reducing the deformation and displacement of a single component, making the deformation of the entire joint more coordinated, and improving the seismic and wind resistance performance of the structure.

[0044] In an alternative solution of this embodiment, preferably, the inner diameter of the ring plate assembly is smaller than the outer diameter of the concrete column 20; and the outer diameter of the ring plate assembly is larger than the outer diameter of the concrete column 20. Since the outer diameter of the ring plate assembly is larger than the outer diameter of the concrete column 20, when the joint is subjected to a large external force, the ring plate can disperse the force to a larger area, avoiding local damage to the surface of the concrete column 20 due to stress concentration, such as column corner breakage, concrete spalling, etc., thereby protecting the integrity of the concrete column 20 and improving its bearing capacity; the outer diameter of the ring plate assembly being larger than the outer diameter of the concrete column 20 provides a larger area for the connection between the concrete slab 30 and the joint. When pouring the concrete slab 30, the concrete can better wrap the ring plate, forming a more reliable bond between the ring plate and the concrete slab 30, increasing the connection force between the slab and the column, improving the efficiency of the joint in transferring loads, and ensuring that the loads on the concrete slab 30 can be effectively transferred to the concrete column 20.

[0045] In an alternative solution of this embodiment, preferably, as Figure 2 and Figure 3 shown, the widths of the upper flange 13 and the lower flange 14 on the cruciform steel 12 gradually increase from the end far from the middle steel pipe 11 to the end close to the middle steel pipe 11. By setting the flanges with gradually decreasing widths, it can ensure good bending resistance while reducing the amount of steel used; the increase in the flange width near the middle steel pipe 11 can increase the section modulus of the cruciform steel 12 at this part, thereby improving its bending resistance. At the slab-column connection joint, the bending moment is relatively large. This design of gradually changing flange widths can better resist the bending moment, reduce the deformation of the cruciform steel 12, and improve the overall stability of the joint; since a smaller flange width is adopted at the part far from the middle steel pipe 11, while ensuring the joint performance, the self-weight of the structure is reduced, which is very beneficial to the force of the entire structure and the foundation design, can reduce the burden on the foundation, and improve the economy and safety of the structure.

[0046] In an alternative solution of this embodiment, preferably, as Figure 2 and Figure 3 shown, the ring plate assembly includes an upper ring plate 16 and a lower ring plate 17; in the vertical axis direction of the middle steel pipe 11, the upper ring plate 16 is arranged parallel above the lower ring plate 17; and a plurality of stiffening ribs 18 are fixedly connected between the upper ring plate 16 and the lower ring plate 17, and each stiffening rib 18 is perpendicularly arranged with respect to the upper ring plate 16 and the lower ring plate 17. The stiffening ribs 18 connect the upper ring plate 16 and the lower ring plate 17 together, enabling the load to be more evenly distributed on the ring plate assembly. When the load on the concrete slab 30 is transferred to the ring plate assembly, the stiffening ribs 18 can disperse the load to each part of the upper ring plate 16 and the lower ring plate 17, avoiding load concentration in a certain area, thereby reducing the local stress of the ring plate and improving the overall mechanical performance of the joint.

[0047] Specifically, the upper ring plate 16 and the lower ring plate 17 have the same shape, and the width of the upper ring plate 16 and the lower ring plate 17 should be greater than 1 / 3 of the diameter of the concrete column 20, and its thickness should be greater than the steel plate thickness of the cross-shaped steel 12.

[0048] Specifically, the thickness of the stiffening rib 18 is the same as the thickness of the web 121 of the cross-shaped steel 12, and the width of the stiffening rib 18 is not less than 1 / 2 of the width of the upper ring plate 16 and the lower ring plate 17.

[0049] Specifically, the setting of the ring plate assembly can increase the contact area with the concrete slab 30, thereby improving the integrity of the slab-column joint system.

[0050] Specifically, both ends of the upper ring plate 16 are fixedly connected to the corresponding upper flanges 13 on the corresponding sides of two adjacent cross-shaped steels 12, and both ends of the lower ring plate 17 are fixedly connected to the corresponding lower flanges 14 on the corresponding sides of two adjacent cross-shaped steels 12.

[0051] Specifically, a stiffening rib 18 is provided between the upper flange 13 and the lower flange 14 on the same side of the cross-shaped steel 12. The upper end of the stiffening rib 18 corresponds to the connection position between the upper ring plate 16 and the upper flange 13 of the cross-shaped steel 12, and the lower end of the stiffening rib 18 corresponds to the connection position between the lower ring plate 17 and the lower flange 14 of the cross-shaped steel 12.

[0052] Specifically, the joint device 10, the upper outer sleeve 21 and the lower outer sleeve 22 are all prefabricated parts; after the joint device 10 is prefabricated, concrete is poured in advance in its voids (such as the voids between the upper ring plate 16 and the lower ring plate 17, etc., to reduce the problem of insufficient pouring in the voids during the overall pouring of concrete), and the concrete should preferably use first-class graded coarse aggregate to prevent incomplete compaction; and when the joint device 10 is manufactured, intumescent fireproof coating should be sprayed at the weld to prevent stress concentration at the weld and brittle fracture at high temperatures.

[0053] Specifically, one end of the upper flange 13 and the lower flange 14 is welded to the side wall of the square steel pipe (a kind of middle steel pipe 11), and the width of this end should not be less than 1 / 3 of the side width of the square steel pipe.

[0054] Specifically, the minimum width of the upper flange 13 and the lower flange 14 fixed at one end of the cross-shaped steel 12 is greater than 5 times the diameter of the steel bolt 15.

[0055] Specifically, the joint device 10 can be completed by simple welding.

[0056] Among them, the relevant settings of the concrete column 20 and the concrete slab 30 are described as follows:

[0057] In the alternative scheme of this embodiment, preferably, such as Figure 1 and Figure 4As shown in the figure, the concrete column 20 includes an upper outer sleeve 21 and a lower outer sleeve 22; the steel reinforcement cage of the concrete column 20 is located inside the upper outer sleeve 21 and the lower outer sleeve 22, and the concrete column 20 is formed by pouring concrete; in the vertical axis direction of the middle steel pipe 11, the upper outer sleeve 21 is sleeved on the middle steel pipe 11 above each cross-shaped steel 12; and the lower outer sleeve 22 is sleeved on the middle steel pipe 11 below each cross-shaped steel 12; and the distance between the lower end of the upper outer sleeve 21 and the upper surface of the concrete slab 30, and the distance between the upper end of the lower outer sleeve 22 and the lower surface of the concrete slab 30 are both 0.5 cm to 1 cm. The reserved distance of 0.5 cm to 1 cm can provide a certain deformation space for the structure when it is stressed. The concrete column 20 and the concrete slab 30 will generate deformation and displacement under the influence of factors such as load bearing and temperature change. This distance can prevent the upper outer sleeve 21 and the lower outer sleeve 22 from restricting each other's deformation due to rigid contact with the concrete slab 30, thereby reducing the additional stress generated by inconsistent deformation and improving the safety and reliability of the structure.

[0058] Specifically, the column longitudinal reinforcements 23 of the steel reinforcement cage of the concrete column 20 are circumferentially distributed around the axis of the concrete column 20 (the distance between two adjacent column longitudinal reinforcements 23 for the cross-shaped steel 12 and the corresponding upper flange 13 and lower flange 14 to pass through is relatively larger than that at other positions), and the column longitudinal reinforcements 23 can be arranged in a circular or square pattern. There is a gap between two adjacent column longitudinal reinforcements 23. One end of the cross-shaped steel 12 is located outside the column longitudinal reinforcements 23 away from the axis of the concrete column 20, and the other end of the cross-shaped steel 12 passes through the gap between two adjacent column longitudinal reinforcements 23 and is fixedly connected to the middle steel pipe 11 located inside the column longitudinal reinforcements 23 close to the axis of the concrete column 20.

[0059] Specifically, the cross-sections of the upper outer sleeve 21 and the lower outer sleeve 22 can be circular or square; when the upper outer sleeve 21 and the lower outer sleeve 22 are PVC-FRP pipes, the FRP used can be any one of AFRP, BFRP, CFRP, GFRP, and PFRP.

[0060] Among them, the descriptions of other related settings are as follows:

[0061] In an alternative embodiment of the present embodiment, preferably, non-node stirrups are provided in the concrete column 20. The non-node stirrups are located within the concrete column 20 and on the outer side of the column longitudinal bars 23 of the steel reinforcement cage of the concrete column 20 away from the axis of the concrete column 20. The non-node stirrups are fixedly connected to the column longitudinal bars 23 of the steel reinforcement cage of the concrete column 20. Node area stirrups are provided on the outer side of the middle steel pipe 11 away from its axis. The node area stirrups are fixedly connected to the column longitudinal bars 23 of the steel reinforcement cage of the concrete column 20. The non-node stirrups are arranged inside the concrete column 20 and outside the column longitudinal bars 23, which can restrain the concrete inside the column. When the concrete is stressed, its lateral deformation is restricted, thereby improving the compressive strength and ductility of the concrete, enabling the concrete column 20 to withstand greater pressure and enhancing the bearing capacity of the structure. The node area is a key part of the slab-column connection, with complex forces, large shear forces and bending moments. The node area stirrups can effectively restrain the concrete in the node core area, improve its shear strength, bear and transfer the shear force at the node, prevent the concrete in the node core area from shear failure, and ensure the reliability of the slab-column connection node.

[0062] When using the reinforced concrete slab-column connection node provided above, first, wind the fiber-reinforced composite material (FRP) strips impregnated with epoxy resin around the PVC pipe at a certain interval. During the winding process, the FRP strips need to be tightened to ensure close contact between the FRP and the PVC pipe. The width, interval and number of layers of the FRP strips can be calculated and determined according to the design value of the column bearing capacity. Cure the PVC-FRP pipe at room temperature until the epoxy resin glue cures to form the final PVC-FRP pipe.

[0063] After each part of the node device 10 is processed, place the cross-shaped steel 12 at a 45° angle obliquely and weld it to the square steel pipe using double-sided fillet welds. Then weld the upper flange 13 and the lower flange 14 to the square steel pipe and the cross-shaped steel 12 using double-sided fillet welds. Then weld the stiffening rib 18 to the upper ring plate 16 and the lower ring plate 17 using double-sided welds. Subsequently, weld the upper ring plate 16 and the lower ring plate 17 to the adjacent upper flange 13 and lower flange 14 using full penetration groove welds. Then install the steel bolts 15 on the upper flange 13 and the lower flange 14. Spray intumescent fireproof coating on the welds of the node device 10 after installation, and pour concrete at the gaps. Then tie the steel reinforcement cages of the concrete column 20 and the concrete slab 30 (during this process, the upper outer sleeve 21 and the lower outer sleeve 22 need to be positioned and installed), and at the same time position the location of the node device 10, and finally pour the concrete integrally.

[0064] In the present invention, specific examples are used to illustrate the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A reinforced concrete slab-column connection node, characterized in that: Including concrete columns, concrete slabs and node devices; The node device includes a central steel pipe and a plurality of cross-shaped steels; each of the cross-shaped steels is fixedly arranged on the circumferential outer side wall of the central steel pipe around the axis of the central steel pipe, and each of the cross-shaped steels is located at the same height in the vertical axis direction of the central steel pipe; The upper end and the lower end of the middle steel pipe are both located in the steel cage of the concrete column; The parts of the middle steel pipe having the cross-shaped steels are all located in the steel cage of the concrete slab; The cross-shaped steel is formed by two webs fixedly connected in a cross shape, and each web of the cross-shaped steel forms an acute angle with the upper surface of the concrete slab.

2. The reinforced concrete slab-column connection node according to claim 1, characterized in that: In the vertical axis direction of the middle steel pipe, the upper end of each of the cross-shaped steels is fixedly connected to the outer side wall of the middle steel pipe located above the cross-shaped steel through at least one upper flange; and the lower end of each of the cross-shaped steels is fixedly connected to the outer side wall of the middle steel pipe located below the cross-shaped steel through at least one lower flange; Furthermore, in the vertical axis direction of the middle steel pipe, the upper end of each upper flange and the lower end of each lower flange are both located in the concrete column.

3. The reinforced concrete slab-column connection node according to claim 2, characterized in that: A connecting column is fixedly provided on each of the upper flanges and each of the lower flanges located in the concrete slab; In the vertical axis direction of the middle steel pipe, the upper end of each connecting column on the upper flange protrudes from the upper plane of the upper flange; and the lower end of each connecting column on the lower flange protrudes from the lower plane of the lower flange.

4. The reinforced concrete slab-column connection node according to claim 1, characterized in that: The concrete column comprises an upper outer casing and a lower outer casing; the steel cage of the concrete column is located in the upper outer casing and the lower outer casing, and the concrete column is formed by pouring concrete; In the vertical axis direction of the middle steel pipe, the upper outer sleeve is sleeved on the middle steel pipe above each cross-shaped steel; and the lower outer sleeve is sleeved on the middle steel pipe below each cross-shaped steel; The distances between the lower end of the upper outer sleeve and the upper surface of the concrete slab, and between the upper end of the lower outer sleeve and the lower surface of the concrete slab are both 0.5 cm to 1 cm.

5. The reinforced concrete slab-column connection node according to claim 1, characterized in that: Each of the cross-shaped steels is evenly distributed circumferentially around the vertical axis of the middle steel pipe; Two adjacent cross-shaped steels are fixedly connected together via a ring plate assembly.

6. The reinforced concrete slab-column connection node according to claim 5, characterized in that: The inner diameter of the ring plate assembly is smaller than the outer diameter of the concrete column; and the outer diameter of the ring plate assembly is larger than the outer diameter of the concrete column.

7. The reinforced concrete slab-column connection node according to claim 2, characterized in that: The widths of the upper flange and the lower flange on the cross-shaped steel gradually increase from an end away from the middle steel pipe to an end close to the middle steel pipe.

8. The reinforced concrete slab-column connection node according to claim 1, characterized in that: The concrete column is provided with non-node stirrups, the non-node stirrups are located in the concrete column and outside the column longitudinal reinforcement of the steel cage of the concrete column away from the axis of the concrete column, and the non-node stirrups are fixedly connected to the column longitudinal reinforcement of the steel cage of the concrete column; The outer side of the middle steel pipe away from the axis thereof is provided with node area stirrups, and the node area stirrups are fixedly connected to the column longitudinal reinforcement of the steel cage of the concrete column.

9. The reinforced concrete slab-column connection node according to claim 6, characterized in that: The ring plate assembly comprises an upper ring plate and a lower ring plate; In the vertical axis direction of the middle steel pipe, the upper ring plate is arranged parallel to the upper part of the lower ring plate; and a plurality of stiffening ribs are fixedly connected between the upper ring plate and the lower ring plate, and each stiffening rib is arranged perpendicularly to the upper ring plate and the lower ring plate respectively.

10. The reinforced concrete slab-column connection node according to claim 2, characterized in that: In the vertical axis direction of the middle steel pipe, the upper and lower ends of the web are fixedly provided with extended side plates, and the extended side plates are fixedly connected to the corresponding parts of the corresponding upper flange or the lower flange.

Images