A beam-column joint of a horizontally precast floor slab without support and its construction method

Abstract

The present invention relates to a beam-column joint for a non-supported horizontal precast floor slab and its construction method. The beam-column joint includes a frame column, and the longitudinal steel bars of the frame column are centrally distributed at the corners of the frame column and extend into the beam-column joint area; a precast frame beam, the end of which is provided with an extension into the beam-column joint area and is bent to form a hook; a steel corbel, which is installed on the side of the frame column and is used to support the precast frame beam. The construction method is as follows: pouring or installing the frame column and installing the steel corbel; then placing the precast frame beam on the steel corbel; the precast frame beam partially extends into the beam-column joint, and then a high-strength grouting material is used to fill the void area between the temporary completion surface of the frame column and the bottom surface of the precast frame beam; installing stirrups in the joint area of the column longitudinal steel bars and the beam bottom longitudinal steel bars; finally, pouring joint concrete in the beam-column joint area. The present invention can realize a beam-column joint for a non-supported horizontal precast floor slab, improve the construction speed and quality of the project, and reduce the cost.

Description

Technical Field

[0001] The present invention relates to the technical field of building node connection, in particular to a beam-column node of a horizontally precast floor without support and its construction method. Background Art

[0002] When using composite beams in existing precast concrete buildings, supports are usually required during the construction stage. When the storey height is large or there are skip-floor columns, the support system is complex to erect and costly. Therefore, in order to simplify the support system and reduce project measure costs, the beam-column node structure design that can achieve the support-free technology during the construction stage is very valuable.

[0003] In order to avoid affecting the splicing of column longitudinal reinforcements around, in the construction stage, the length of the precast frame beam extending into the column concrete part is short, that is, usually the column concrete cover thickness, which is used for closing the slurry during the pouring of the beam-column node concrete, cannot transfer force reliably, and cannot achieve support-free and formwork-free. Summary of the Invention

[0004] The purpose of the present invention is to provide a beam-column node of a horizontally precast floor without support and its construction method that can improve the construction speed and quality of the project and reduce the cost.

[0005] The present invention is realized by the following technical solutions: A beam-column node of a horizontally precast floor without support, which includes

[0006] Frame column 1, the longitudinal reinforcements 7a of the frame column 1 are centrally distributed at the corners of the frame column 1 and extend into the beam-column node area;

[0007] The end of the precast frame beam 4 is provided with a bottom longitudinal reinforcement 8 that extends into the beam-column node area and is bent to form a hook, and the hook is in the same direction as the extension direction of the column longitudinal reinforcement 7a;

[0008] Steel corbel 2, installed on the side of the frame column 1, used to support the precast frame beam 4, so that the bottom surface of the precast frame beam 4 is slightly higher than the temporary completion surface 11 of the frame column 1;

[0009] Among them, within the scope of the frame beam-column node, special-shaped combined stirrups for ensuring the seismic performance of the node area are installed between the column longitudinal reinforcements 7a;

[0010] Part of the end of the precast frame beam 4 extends into the beam-column node area, and the space between the bottom surface of the precast frame beam 4 and the temporary completion surface of the frame column is filled with high-strength grouting material; at the same time, part of the end of the precast frame beam 4 extends into the beam-column node area, so that the beam-column node area forms an X-shaped post-cast area. After pouring the concrete in the beam-column node area, it can be used as the basic frame for the installation of the horizontally precast floor without support.

[0011] Construction method of the beam-column node of the horizontally precast floor without support,

[0012] The specific steps are as follows:

[0013] Step 1: Pour or install the frame column 1, and install the steel corbel 2 when it reaches the design conditions;

[0014] Step 2: Place the precast frame beam 4 on the steel corbel 2 and let a part of the precast frame beam 4 extend into the beam-column joint area;

[0015] Step 3: Use high-strength grouting material 5 to fill the void area between the temporary completion surface 11 of the frame column 1 and the bottom surface of the precast frame beam 4;

[0016] Step 4: Install special-shaped combined stirrups between the longitudinal column bars 7a to form stirrups for ensuring the seismic performance of the joint area;

[0017] Step 5: Pour joint concrete 6 in the beam-column joint area.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. During the construction stage, the horizontal precast floor slab can be supported without supports. The steel corbel 2 at the column top can jointly bear the load on the precast frame beam with the column, and the force transmission is reliable, which is especially suitable for buildings such as industrial plants and logistics warehouses with high load requirements;

[0020] 2. The precast frame beam is supported by a steel corbel at the column top and has sufficient adjustment ability, enabling support-free construction.

[0021] 3. The longitudinal column bars are concentratedly arranged at the column corners, and the longitudinal beam bottom bars in the same direction are horizontally staggered, reducing the steel bar density at the joint, being easy to install and improving the efficiency. Description of the Drawings

[0022] Figure 1 It is a structural schematic diagram of the unidirectional precast frame beam at the joint of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the bidirectional precast frame beam at the joint of the present invention;

[0024] Figure 3 It is a structural schematic diagram of the frame column;

[0025] Figure 4 It is Figure 3 a longitudinal sectional view of

[0026] Figure 5 It is a structural schematic diagram of the frame column with the steel corbel installed;

[0027] Figure 6 It is Figure 5 a longitudinal sectional view of

[0028] Figure 7Effect diagram during the installation of precast frame beam (longitudinal column bars are omitted in the figure);

[0029] Figure 8 Plan view at the joint of the present invention;

[0030] Figure 9 Three-dimensional display diagram of stirrups in the joint area.

[0031] Label description: 1 - Frame column, 11 - Temporary finished surface, 2 - Steel corbel, 4 - Precast frame beam, 5 - Void area, 7a - Longitudinal column bars, 7b - Inner longitudinal bars, 8 - Longitudinal bottom bars of beam, 9a - First stirrup in joint area, 9b - Second stirrup in joint area, 9c - Third stirrup in joint area. Specific implementation mode

[0032] The present invention will be described in detail below with reference to the accompanying drawings:

[0033] As Figures 1-9 shown: A beam-column joint of a non-support horizontal precast floor slab, which includes

[0034] Frame column 1, the longitudinal bars 7a of the frame column 1 are concentratedly distributed at the corners of the frame column 1 and extend into the beam-column joint area;

[0035] The end of the precast frame beam 4 is provided with longitudinal bottom bars 8 that extend into the beam-column joint area and are bent to form a hook, and the hook is in the same extending direction as the longitudinal column bars 7a; here, the longitudinal bottom bars 8 extending into the beam-column joint area can adopt a 90-degree hook at the end; of course, forms such as a steel bar anchorage plate can also be used.

[0036] Steel corbel 2, installed on the side of the frame column 1, used to support the precast frame beam 4, so that the bottom surface of the precast frame beam 4 is slightly higher than the temporary finished surface 11 of the frame column 1; here, the temporary finished surface 11 refers to the top surface of the frame column 1 before grout and concrete pouring.

[0037] Among them, within the scope of the frame beam-column joint, special-shaped combined stirrups for ensuring the seismic performance of the joint area are installed between the longitudinal column bars 7a; here, all vertical bars located within the frame beam-column joint are processed by stirrups.

[0038] Part of the end of the precast frame beam 4 extends into the beam-column joint area, and the space between the bottom surface of the precast frame beam 4 and the temporary finished surface of the frame column is filled with high-strength grout; at the same time, part of the end of the precast frame beam 4 extends into the beam-column joint area, so that an X-shaped post-cast area is formed in the beam-column joint area. After pouring the concrete in the beam-column joint area, it can be used as the basic frame for the installation of the non-support horizontal precast floor slab.

[0039] The frame column 1 is basically the same as the existing structural column, except that the distribution of the longitudinal reinforcement bars in the frame column 1 is divided into a dense area and a sparse area. The longitudinal reinforcement bars in the present invention are mainly distributed at the corners of the frame column 1 to form column longitudinal reinforcement bars 7a; a small number of inner longitudinal reinforcement bars 7b are distributed in other areas (see Figure 3 , 4 ); in addition, the column longitudinal reinforcement bars 7a distributed at the corners of the frame column 1 also extend into the beam-column joint area.

[0040] Here, a steel corbel 2 is added, and the top surface height H1 of the steel corbel 2 (which is also the bottom surface height of the precast frame beam) is higher than the temporary completion surface height H2 of the frame column 1 (see Figure 6 ).

[0041] The distance between the top surface of the steel corbel 2 and the temporary completion surface of the frame column 1 ranges from 10 mm to 100 mm (i.e., the distance of the void area mentioned in the construction method).

[0042] The column longitudinal reinforcement bars 7a at any corner of the frame column 1 are arranged in a rectangular shape.

[0043] When installing, for two precast frame beams 4 in the same direction, the bottom longitudinal reinforcement bars 8 extending into the beam-column joint area are horizontally offset from each other, preferably in an anti-symmetric relationship.

[0044] Among them, the special-shaped combined stirrups include

[0045] The first joint area stirrup 9a: The column longitudinal reinforcement bars 7a at any corner of the frame column 1 are enclosed by welded closed stirrups;

[0046] The second joint area stirrup 9b: Enclose the hooks of the column longitudinal reinforcement bars 7a and the bottom longitudinal reinforcement bars 8 located in the same column; it should be noted that the second joint area stirrup 9b should enclose as many hooks of the column longitudinal reinforcement bars 7a and the bottom longitudinal reinforcement bars 8 located in the same column as possible.

[0047] The third joint area stirrup 9c: Enclose part of the hooks of the bottom longitudinal reinforcement bars 8.

[0048] The special-shaped combined stirrups (9a\9b\9c) ensure the seismic performance of the joint area.

[0049] The construction method of the beam-column joint of the un-supported horizontal precast floor slab disclosed in the present invention is specifically as follows:

[0050] Step 1: Pour or install the frame column 1, and install the steel corbel 2 when it reaches the design conditions;

[0051] Step 2: Place the precast frame beam 4 on the steel corbel 2 and let part of the precast frame beam 4 extend into the beam-column joint area;

[0052] Step 3: Use high-strength grouting material 5 to fill the void area between the temporary completion surface 11 of the frame column 1 and the bottom surface of the precast frame beam 4;

[0053] Step 4: Install special-shaped combined stirrups between the longitudinal column bars 7a to form special-shaped combined stirrups that ensure the seismic performance of the joint area;

[0054] Step 5: Pour joint concrete 6 in the beam-column joint area. The frame joint here forms an in-situ cast area in an X shape (as Figure 8 shown). After pouring the joint, it can be used as the basic load-bearing system for installing the un-supported horizontal precast floor slab.

[0055] The steel corbels 2 in Step 1 are distributed relatively, and the relatively distributed steel corbels 2 are connected and fixed by bolts and nuts passing through the frame column.

[0056] In Step 2, the installation sequence of the precast frame beam 4 is based on the height difference between the bottom surface of the precast frame beam 4 and the temporary completion surface of the frame column 1; the smaller the height difference between the two, the higher the installation priority.

[0057] The length range of the precast frame beam 4 extending into the beam-column joint area is between 50 mm and 200 mm (i.e., corresponding to Figure 7 A in).

[0058] In Step 4, the joint area stirrups include

[0059] The first joint area stirrup 9a: Four longitudinal column bars 7a at any corner of the frame column 1 are enclosed by a welded closed stirrup;

[0060] The second joint area stirrup 9b: Enclose the hooks of the longitudinal column bars 7a and the longitudinal beam bottom bars 8 located in the same column;

[0061] The third joint area stirrup 9c: Enclose part of the hooks of the longitudinal beam bottom bars 8.

[0062] Although the present invention is illustrated and described by specific embodiments and their alternative forms, it should be understood that various changes and modifications can be implemented as long as they do not deviate from the spirit of the present invention. Therefore, it should be understood that the present invention is not limited in any sense except by the limitations of the appended claims and their equivalent conditions.

Claims

1. A beam-column joint of a self-supporting horizontal precast floor slab, characterized in that: it includes a frame column (1), the longitudinal steel bars (7a) of the frame column (1) are centrally distributed at the corners of the frame column (1) and extend into the beam-column joint area; a precast frame beam (4), with longitudinal bottom steel bars (8) at the end extending into the beam-column joint area and bent to form a hook, and the hook is in the same direction as the extending direction of the column longitudinal steel bars (7a); a steel corbel (2), installed on the side of the frame column (1) to support the precast frame beam (4), so that the bottom surface of the precast frame beam (4) is slightly higher than the temporary completion surface (11) of the frame column (1); wherein, within the range of the frame beam-column joint, special-shaped combined stirrups are installed between the column longitudinal steel bars (7a) to ensure the seismic performance of the joint area; the end part of the precast frame beam (4) extends into the beam-column joint area, and the space between the bottom surface of the precast frame beam (4) and the top surface of the frame column is filled with high-strength grouting material; at the same time, the end part of the precast frame beam (4) extends into the beam-column joint area, so that an X-shaped post-cast area is formed in the beam-column joint area. After pouring the concrete in the beam-column joint area, it can be used as the basic frame for the installation of the self-supporting horizontal precast floor slab; the special-shaped combined stirrups include the first joint area stirrup (9a): the column longitudinal steel bars (7a) at any corner of the frame column (1) are enclosed by welded closed stirrups; the second joint area stirrup (9b): enclosing the column longitudinal steel bars (7a) and the hooks of the longitudinal bottom steel bars (8) on the same column; the third joint area stirrup (9c): enclosing part of the hooks of the longitudinal bottom steel bars (8).

2. The beam-column joint of the self-supporting horizontal precast floor slab according to claim 1, characterized in that: the distance between the top surface of the steel corbel (2) and the temporary completion surface of the frame column (1) ranges from 10 mm to 100 mm.

3. The beam-column joint of the self-supporting horizontal precast floor slab according to claim 1, characterized in that: the column longitudinal steel bars (7a) at any corner of the frame column (1) are arranged in a rectangular shape.

4. The beam-column joint of the self-supporting horizontal precast floor slab according to claim 1, characterized in that: for two precast frame beams (4) installed in the same direction, the longitudinal bottom steel bars (8) extending into the beam-column joint area are horizontally offset from each other.

5. The construction method of the beam-column joint according to any one of claims 1-4, characterized in that: the specific steps are as follows: Step 1: Pour or install the frame column (1), and install the steel corbel (2) when it reaches the design conditions; Step 2: Place the precast frame beam (4) on the steel corbel (2) and let part of the precast frame beam (4) extend into the beam-column joint area; Step 3: Use high-strength grouting material (5) to fill the void area between the temporary completion surface (11) of the frame column (1) and the bottom surface of the precast frame beam (4); Step 4: Install joint area stirrups between the column longitudinal steel bars (7a) to form special-shaped combined stirrups to ensure the seismic performance of the joint area; Step 5: Pour joint concrete (6) in the beam-column joint area; wherein, in step 4, the special-shaped combined stirrups include The first joint area stirrup (9a): Four longitudinal column bars (7a) at any corner of the frame column (1) are enclosed by a welded closed stirrup; The second joint area stirrup (9b): Encloses the hooks of the longitudinal column bars (7a) and the longitudinal bottom beam bars (8) located in the same column; The third joint area stirrup (9c): Encloses the hooks of part of the longitudinal bottom beam bars (8).

6. The construction method of the beam-column joint according to claim 5, characterized in that: The steel corbels (2) in step 1 are distributed relatively, and the relatively distributed steel corbels (2) are connected and fixed by screws and nuts passing through the frame column.

7. The construction method of the beam-column joint according to claim 5, characterized in that: In step 2, the installation order of the precast frame beam (4) is based on the height difference between the bottom surface of the precast frame beam (4) and the top surface of the frame column (1); the smaller the height difference between the two, the higher the installation priority.

8. The construction method of the beam-column joint according to claim 5, characterized in that: The length range of the precast frame beam (4) extending into the beam-column joint area is between 50 mm and 200 mm.

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