Steel connection prefabricated concrete frame structure and support-free construction method

Abstract

The invention provides a steel connection prefabricated concrete frame structure and a support-free construction method, and aims to simplify construction procedures and improve the anti-seismic property of beam column joints. The structure comprises a column and a precast beam, the column can be a cast-in-place column or a precast column, and steel structure embedded parts are embedded in the top of the column along each side. I-shaped beam end section steel is arranged at the ends of the precast beams, lower flanges of the I-shaped beam end section steel are placed on the steel structure embedded parts of the columns, and the lower flanges and the upper flanges of the precast beams are connected through the connecting steel plates and the polygonal steel plates in a welded mode. The beam end profile steel is provided with stiffening ribs, and the stress requirement in the construction stage is met. According to the node structure, the precast beam can be installed without a temporary supporting frame or a supporting bracket. The construction method comprises the steps of hoisting the columns and the beams, welding the beam-column joints, installing stirrups in joint areas, sealing joint formworks, pouring concrete and the like. According to the fabricated beam-column joint, the structure and the construction process of the fabricated beam-column joint are greatly simplified, the construction difficulty and the engineering cost are reduced, and the fabricated beam-column joint has good anti-seismic performance and economical efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction, and relates to a steel-connected precast concrete frame structure and a support-free construction method. Background Art

[0002] In prefabricated concrete structures, conventional connection nodes between precast beams and precast columns are generally cast in a reserved node area, where precast beams and precast columns need to extend the force-bearing steel bars and anchor them in the post-cast node area to ensure the force-bearing performance of the node. This structure has reliable force transmission, but the connection structure is very complex, and the protruding steel bars of the beams and columns collide with each other, making construction difficult. At the same time, this connection method requires the installation of additional temporary support frames at the ends of the precast beams, or the installation of extended temporary support brackets at the tops of the precast columns for temporary placement of the precast beams. After the beam-column nodes are cast, the temporary support frames or temporary support brackets still need to be disassembled. Therefore, the construction process of conventional connection methods is more complicated and the construction cost is higher. Summary of the invention

[0003] In view of this, the purpose of the present invention is to solve the above-mentioned problems and provide a steel-connected precast concrete frame structure and a support-free construction method, which can achieve fast and simple node connection by eliminating the anchor steel bars and supporting components at the beam ends, improve seismic performance, and reduce construction costs.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A steel-connected precast concrete frame structure, comprising columns and precast beams, wherein the columns are precast columns or cast-in-place columns; steel structure embedded parts are pre-embedded along each side of the top of the columns, and each steel structure embedded part serves as a support for the precast beam on that side;

[0006] The end of the prefabricated beam is provided with a beam end steel embedded in the concrete and extending to the outside; the beam end steel is an I-shaped section, including an upper flange, a lower flange and a web; the end of the web is provided with a plurality of through holes, and the stirrups of the prefabricated column are passed through the through holes and then tied and fixed with the longitudinal steel bars;

[0007] There are four precast beams, which are respectively located on the four sides of the column. The beam end steel of each precast beam is placed on a corresponding steel structure embedded part. The lower flange of the precast beam is placed on the steel structure embedded part, and the lower flanges of the two relatively arranged precast beams are welded and connected by connecting steel plates; the upper flanges of all precast beams are welded and connected to each other by a polygonal steel plate;

[0008] The concrete interface at the end of the precast beam is provided with a shear keyway. The steel section at the end of the beam is also provided with stirrups and side structural longitudinal reinforcement. The node area and the steel section at the end of the beam are poured with concrete of the same strength as the column.

[0009] Furthermore, the end of the beam end steel is provided with a stiffening rib perpendicular to the web, the two ends of the stiffening rib are respectively connected to the upper flange and the lower flange, and the side is connected to the web; the stiffening rib is located on the inner side of the stirrups of the column.

[0010] Furthermore, when the upper flange and the lower flange of the beam end steel section intersect with the longitudinal reinforcement of the column, through holes are opened on the upper flange and the lower flange, and the longitudinal reinforcement of the column passes through the through holes.

[0011] Furthermore, the longitudinal steel bars at the top and bottom of the column extend to the outside, and the longitudinal steel bars between the columns of the upper and lower adjacent sections are connected by grouting sleeves or mechanical sleeves, and the height of the connection point is set in the middle area of ​​the beam-column node; when prefabricated columns are used, the concrete bottom surface elevation of the upper prefabricated columns is lower than the top surface elevation of the floor slab of that layer.

[0012] Furthermore, the connecting steel plate and the lower flange of the beam end steel section are of equal width and thickness, and the butt joint cross-sections of the polygonal steel plate and the upper flange of the beam end steel section are the same.

[0013] A support-free construction method for the steel-connected precast concrete frame structure as described above comprises the following steps:

[0014] (1) When the columns are prefabricated, the columns and beams are prefabricated in the factory, and the prefabricated columns are hoisted in place first, and then the prefabricated beams are hoisted; when the columns are cast in place, the curing columns are cast in situ first and reach the design strength, and then the prefabricated beams are hoisted;

[0015] (2) Place the beam end steel on the embedded steel structure parts at the top of the column;

[0016] (3) Use a connecting steel plate with the same width and thickness as the lower flange of the beam end steel to weld the lower flanges of the beam end steel on both sides of the column;

[0017] (4) Use a polygonal steel plate to weld the upper flanges of the beam end steel sections on both sides of the column;

[0018] (5) When the columns are prefabricated, the prefabricated columns of the previous layer are hoisted; when the columns are cast-in-place, the longitudinal reinforcement of the columns of the previous layer is installed, and then the longitudinal reinforcement of the upper and lower columns is quickly connected by grouting sleeves or mechanical sleeves;

[0019] (6) Use multiple L-shaped short steel bars, pass through the through holes of the web and then weld them to form stirrups in the column end node area;

[0020] (7) Install the casting formwork in the beam-column joint area;

[0021] (8) Install cast-in-place or precast floor slabs, and then pour concrete at the nodes of this layer.

[0022] Optionally, in step (5), when prefabricated columns are used, after the longitudinal reinforcements of the upper and lower columns are connected, temporary inclined supports of the upper prefabricated columns are installed to calibrate the verticality.

[0023] The beneficial effects of the present invention are:

[0024] 1. In the present invention, since the anchor steel bars at the ends of beams in conventional connection nodes are eliminated, the structure is greatly simplified, the difficulty of construction and installation is greatly reduced, and the beam-column node assembly is fast. At the same time, the addition of embedded connectors in the steel structure can ensure that the seismic performance of the beam-column connection node is better than the traditional method, effectively improving the safety of the assembled concrete structure.

[0025] 2. The present invention does not require the installation of additional temporary support frames at the beam ends or temporary support brackets extending outward from the column tops, and can achieve reliable placement of prefabricated beams, greatly simplifying the construction process, reducing project costs and construction safety hazards.

[0026] 3. Different from the conventional steel-concrete beam-column joint structure, the present invention only sets a small amount of steel embedded parts in the column, ensuring the penetration and continuity of the longitudinal reinforcement of the column, greatly reducing the amount of steel used, with good economic efficiency and high market acceptance. At the same time, the connecting parts used in the structure are all covered in concrete, eliminating the need for fire prevention and anti-corrosion measures, and the economic efficiency is better than that of traditional steel structure connection nodes.

[0027] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 It is an overall stereoscopic diagram of the steel-connected precast concrete frame structure of the present invention.

[0030] Figure 2 It is a schematic diagram of the connection node between the beam and the column in the present invention.

[0031] Figure 3 for Figure 2 A partial schematic diagram of the connection node between the center beam and the column.

[0032] Figure 4 Schematic diagram of the construction of prefabricated columns.

[0033] Figure 5 This is a schematic diagram of embedded steel structure parts.

[0034] Figure 6 , 7 Schematic diagram of the construction of precast beams.

[0035] Figure 8 This is a schematic diagram of the embedded parts structure of the steel structure.

[0036] Fig. 9 Schematic diagram of polygonal steel plate.

[0037] Fig.10 It is a schematic diagram of the beams, columns and floor slabs after pouring in the present invention.

[0038] Attached icons: 1-precast column; 2-precast beam; 3-polygonal steel plate; 4-connecting steel plate; 5-floor slab; 11-longitudinal reinforcement; 12-embedded steel structure parts; 13-stirrups; 14-mechanical sleeve; 21-upper flange; 22-stiffening ribs; 23-web; 24-lower flange; 25-stirrups; 26-lateral structural longitudinal reinforcement; 27-shear keyway; 28-through hole; 29-through hole. DETAILED DESCRIPTION

[0039] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0040] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and descriptions in the drawings may be omitted.

[0041] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0042] See also Figures 1 to 9 , which is a steel-connected precast concrete frame structure, including a precast column 1 and a precast beam 2. The top of the precast column 1 is pre-buried with a steel structure embedded part 12 along each side. Each steel structure embedded part 12 serves as a shelf support for the precast beam on this side, and each steel structure embedded part 12 corresponds to the precast beam 2 connected to this side; the end of the precast beam is provided with a beam end steel embedded in the concrete and extending to the outside; the beam end steel is an I-section, including an upper flange 21, a lower flange 24 and a web 23; the end of the web 23 is provided with a plurality of through holes 28, and the stirrups 13 of the precast column pass through the through holes 28. When the upper flange 21 and the lower flange 24 of the beam end steel intersect with the longitudinal steel bar 11 of the column, through holes 29 are opened on the upper flange 21 and the lower flange 24, and the longitudinal steel bar 11 of the column passes through the through holes 29.

[0043] There are 4 precast beams, which are located on the four sides of the column respectively; the beam end steel of each precast beam is placed on a corresponding steel structure embedded part, the lower flange of the precast beam fits the steel structure embedded part, and the lower flanges of the two relatively arranged precast beams are welded and connected by a connecting steel plate 4; the connecting steel plate 4 is equal in width and thickness to the lower flange of the beam end steel, and the cross section of the butt interface between the polygonal steel plate and the upper flange of the beam end steel is the same. The upper flanges of all precast beams are welded and connected to each other by a polygonal steel plate 3.

[0044] The end of the beam end steel is provided with a stiffening rib 22 perpendicular to the web, the two ends of the stiffening rib 22 are respectively connected to the upper flange and the lower flange, and the side is connected to the web; the stiffening rib is located inside the stirrup 13 of the prefabricated column.

[0045] In this embodiment, the longitudinal steel bars 11 at the top and bottom of the precast column extend out, and the longitudinal steel bars 11 between the upper and lower columns are connected to each other through a mechanical sleeve 14, and the connection point height is located in the middle area of ​​the beam-column node. The upper steel bars and the lower steel bars in the precast beam are respectively welded to the upper flange of the beam end steel and the lower flange of the beam end.

[0046] The concrete interface at the end of the precast beam is provided with a shear keyway 27, and the beam end steel section is also provided with stirrups 25 and side structural longitudinal reinforcement 26. The node area and the beam end steel section are poured with concrete of the same strength as the column.

[0047] See also Fig.10 Taking prefabricated columns as an example, the support-free construction method of the steel-connected prefabricated concrete frame structure in this embodiment includes the following steps:

[0048] (1) Prefabricated precast beams 2 and precast columns 1 in the factory;

[0049] (2) During construction, the prefabricated column 1 is first hoisted into place, and then the prefabricated beam 2 is hoisted, and the beam end steel is placed on the steel structure embedded part 12 at the top of the prefabricated column, and then welded and fixed;

[0050] (3) Use a connecting steel plate with the same width and thickness as the lower flange of the beam end steel to weld the lower flanges of the beam end steel on both sides of the precast column;

[0051] (4) Use a polygonal steel plate to weld the upper flanges of the beam end steel sections on both sides of the precast column;

[0052] (5) The prefabricated columns of the upper layer are hoisted, and the longitudinal reinforcements of the upper and lower columns are quickly connected using a mechanical sleeve 14. After the longitudinal reinforcements of the upper and lower columns are connected, the temporary inclined supports of the upper prefabricated columns are installed to calibrate the verticality.

[0053] (6) A plurality of L-shaped short steel bars are used, passed through the through holes 28 of the web plate and then welded to form stirrups in the column end node area;

[0054] (7) Install the casting formwork in the beam-column joint area;

[0055] (8) After installing the cast-in-place or prefabricated floor slab 5, the node area is sealed with a concrete formwork, and then the node concrete of this layer is poured.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A steel-connected precast concrete frame structure, comprising columns and precast beams, characterized in that: The column is a prefabricated column or a cast-in-place column; a steel structure embedded part is pre-embedded along each side of the top of the column, and each steel structure embedded part serves as a support for the prefabricated beam on that side; The end of the prefabricated beam is provided with a beam end steel embedded in the concrete and extending to the outside; the beam end steel is an I-shaped section, including an upper flange, a lower flange and a web; the end of the web is provided with a plurality of through holes, and the stirrups of the prefabricated column are passed through the through holes and then tied and fixed with the longitudinal steel bars; There are four precast beams, which are respectively located on the four sides of the column. The beam end steel of each precast beam is placed on a corresponding steel structure embedded part. The lower flange of the precast beam is placed on the steel structure embedded part, and the lower flanges of the two relatively arranged precast beams are welded and connected by connecting steel plates; the upper flanges of all precast beams are welded and connected to each other by a polygonal steel plate; The concrete interface at the end of the precast beam is provided with a shear keyway. The steel section at the end of the beam is also provided with stirrups and side structural longitudinal reinforcement. The node area and the steel section at the end of the beam are poured with concrete of the same strength as the column.

2. The steel-connected precast concrete frame structure according to claim 1 is characterized in that: The end of the beam end steel is provided with a stiffening rib perpendicular to the web, the two ends of the stiffening rib are respectively connected to the upper flange and the lower flange, and the side surface is connected to the web; the stiffening rib is located on the inner side of the stirrup of the column.

3. The steel-connected precast concrete frame structure according to claim 2 is characterized in that: When the upper flange and the lower flange of the beam end section steel intersect with the longitudinal reinforcement of the column, through holes are opened on the upper flange and the lower flange, and the longitudinal reinforcement of the column passes through the through holes.

4. The steel-connected precast concrete frame structure according to claim 1, characterized in that: The longitudinal steel bars at the top and bottom of the column extend to the outside, and the longitudinal steel bars between the columns of the upper and lower adjacent sections are connected by grouting sleeves or mechanical sleeves, and the height of the connection point is set in the middle area of ​​the beam-column node; when prefabricated columns are used, the concrete bottom surface elevation of the upper prefabricated columns is lower than the top surface elevation of the floor slab of that layer.

5. The steel-connected precast concrete frame structure according to claim 1, characterized in that: The connecting steel plate is of equal width and thickness to the lower flange of the beam end section steel, and the butt interface cross-section of the polygonal steel plate and the upper flange of the beam end section steel is the same.

6. A support-free construction method for a steel-connected precast concrete frame structure as claimed in any one of claims 1 to 5, characterized in that: The steps include: (1) When the columns are prefabricated, the columns and beams are prefabricated in the factory, and the prefabricated columns are hoisted in place first, and then the prefabricated beams are hoisted; when the columns are cast in place, the curing columns are cast in situ first and reach the design strength, and then the prefabricated beams are hoisted; (2) Place the beam end steel on the embedded steel structure parts at the top of the column; (3) Use a connecting steel plate with the same width and thickness as the lower flange of the beam end steel to weld the lower flanges of the beam end steel on both sides of the column; (4) Use a polygonal steel plate to weld the upper flanges of the beam end steel sections on both sides of the column; (5) When the columns are prefabricated, the prefabricated columns of the previous layer are hoisted; when the columns are cast-in-place, the longitudinal reinforcement of the columns of the previous layer is installed, and then the longitudinal reinforcement of the upper and lower columns is quickly connected by grouting sleeves or mechanical sleeves; (6) Use multiple L-shaped short steel bars, pass through the through holes of the web and then weld them to form stirrups in the column end node area; (7) Install the casting formwork in the beam-column joint area; (8) Install cast-in-place or precast floor slabs, and then pour concrete at the nodes of this layer.

7. The support-free construction method according to claim 6, characterized in that: In step (5), when the columns are prefabricated columns, after the longitudinal reinforcements of the upper and lower columns are connected, temporary inclined supports of the upper prefabricated columns are installed to calibrate the verticality.

Images