A construction of layering and continuous building of existing concrete column

Abstract

The utility model provides a kind of layering continued construction of existing concrete column, this construction includes first longitudinal reinforcement, second longitudinal reinforcement and stirrup;A plurality of first longitudinal reinforcement is arranged at the outside of the top of existing structure column, and first longitudinal reinforcement penetrates the removed area of existing structure beam slab;A plurality of second longitudinal reinforcement is arranged at the outside of the top of existing structure column, and lower end of second longitudinal reinforcement is fixed in existing structure beam slab;Stirrup is circumferentially connected to the outside of a plurality of first longitudinal reinforcement and a plurality of second longitudinal reinforcement, and a plurality of new column stirrups is arranged along vertical direction with interval, and the lower part of first longitudinal reinforcement, the lower part of second longitudinal reinforcement and stirrup form the reinforcement system of new column base with section greater than the section of existing structure column at the top of existing structure column, and the upper part of first longitudinal reinforcement and the upper part of second longitudinal reinforcement are used as longitudinal reinforcement of new column.The utility model relates to the field of building construction technology, and can solve the problems of great structural damage risk, low construction efficiency and many construction obstacles in the prior art.

Description

Technical Field

[0001] This utility model relates to the field of building construction technology, and in particular to a structure for adding floors to existing concrete columns. Background Technology

[0002] In the field of existing building renovation and upgrading, to meet the needs of functional changes (such as adding floors or structural modifications) or structural reinforcement, it is often necessary to add vertical structural columns at the top of the existing concrete columns. Current mainstream technologies in the industry include:

[0003] Method 1: Existing rebar anchoring and pouring method.

[0004] This method requires drilling holes in the top of the original column to insert steel bars and pouring new concrete. However, during implementation, the steel bars at the beam-column joint are often too dense, making it difficult for the inserted steel bars to meet the design requirements for seismic resistance specifications, dimensions, and depth, thus affecting the vertical transfer of loads between the old and new structures.

[0005] Method 2: Reconstruction of beam-column joints by chiseling away.

[0006] This method requires chiseling away the concrete column head and surrounding beam concrete to expose the original structural column reinforcement, then extending it by welding the longitudinal reinforcement before recasting. This method not only damages the integrity of the original structure and requires extensive temporary support reinforcement for the surrounding structures, but also causes stress redistribution at the chiseled areas. Furthermore, construction vibrations may cause microcracks to propagate, affecting the long-term durability of the structure.

[0007] The aforementioned traditional methods all suffer from common problems such as high risk of structural damage, low construction efficiency, and numerous construction obstacles. Therefore, there is a need to provide a structure for adding floors to existing concrete columns that can solve the problems of high risk of structural damage, low construction efficiency, and numerous construction obstacles in existing technologies. Utility Model Content

[0008] The purpose of this utility model is to provide a structure for adding floors to existing concrete columns, which can solve the problems of high risk of structural damage, low construction efficiency and many construction obstacles in the existing technology.

[0009] To achieve the above objectives, the technical solution of this utility model is as follows:

[0010] A method for adding a story to an existing concrete column includes: first longitudinal reinforcement, second longitudinal reinforcement, and stirrups; several first longitudinal reinforcements are located on the top outer side of the existing structural column, and several first longitudinal reinforcements penetrate the area to be removed from the existing structural beams and slabs; several second longitudinal reinforcements are located on the top outer side of the existing structural column, and the lower ends of several second longitudinal reinforcements are fixed within the existing structural beams and slabs; both the first and second longitudinal reinforcements are arranged circumferentially along the top outer side of the existing structural column; stirrups are circumferentially connected to the outer side of the first and second longitudinal reinforcements; several new column stirrups are arranged vertically at intervals; the lower parts of the first and second longitudinal reinforcements and the stirrups form a reinforcement system at the column head of the existing structural column, with a cross-section larger than that of the existing structural column, for the new column base; the upper parts of the first and second longitudinal reinforcements serve as the longitudinal reinforcement of the new column.

[0011] The lower end of the first longitudinal bar is bent toward the existing structural column to form an L-shaped anchor bar, and the horizontal section of the L-shaped anchor bar is anchored into the existing structural column.

[0012] The horizontal section of the L-shaped anchor bar is anchored into the existing structural column to a depth of not less than 150mm, and the first longitudinal bar is inserted into the new column base to a depth of 1.2×laE×d, where laE is the seismic anchorage length of the L-shaped anchor bar and d is the diameter of the first longitudinal bar.

[0013] The stirrups located within the height range of the existing structural beams and slabs are composed of several segments of 7-shaped steel bars. These segments of 7-shaped steel bars pass through holes opened in the existing structural beams and slabs and are connected end to end to form a ring-shaped stirrup.

[0014] The stirrups located outside the height range of the existing structural beams and slabs are single-leg stirrups. The two ends of the single-leg stirrups are tied and fixed to the first longitudinal reinforcement. Several single-leg stirrups are circumferentially wrapped around the side of the existing structural column, and the intersection of two adjacent single-leg stirrups is connected and fixed.

[0015] The existing structural beam and slab have several tie bars embedded at the top and bottom, and these tie bars are respectively tied and fixed to several second longitudinal bars.

[0016] An opening is drilled in the top surface of the existing structural column, and the concrete of the new column base is filled into the opening, so that the existing structural column and the new column base are connected into a whole.

[0017] The lower end of the second longitudinal reinforcement is anchored into the existing structural beam and slab, and is staggered from the beam reinforcement in the existing structural beam and slab.

[0018] Compared with the prior art, this utility model has the following advantages:

[0019] This invention utilizes the column head of an existing structural column to form an enlarged cross-section for the new column base, facilitating the addition of new columns. Simultaneously, by drilling through the existing structural beams and slabs around the beam-column joint, the first and second longitudinal reinforcement bars are connected to the existing beam-column joint as a whole, avoiding the core area of ​​the beam-column joint. This solves the difficulties of installing reinforcement bars at the column top and removing concrete from the beam-column joint, achieving a rigid connection between the old and new columns and efficient load transfer. This invention effectively avoids structural damage to the original concrete column-beam joint, utilizes the original structural bearing capacity design, reduces the need for surrounding structural support measures, and improves construction efficiency. It is suitable for the vertical continuation construction of existing structural columns in the design of adding floors to existing buildings, and can meet the core requirements of green renovation of existing buildings. Attached Figure Description

[0020] The above and other objects, features and advantages of this disclosure will become more apparent from the accompanying drawings, in which like reference numerals generally denote like parts.

[0021] Figure 1 This is a structural schematic diagram of an existing concrete column addition and extension structure according to the present invention.

[0022] Figure 2 yes Figure 1 Cross-sectional view of AA.

[0023] In the diagram, 1 is the first longitudinal reinforcement, 2 is the opening, 3 is the second longitudinal reinforcement, 4 is the stirrup, 5 is the existing structural beam and slab, 6 is the existing structural column, 7 is the L-shaped anchor bar, 8 is the tie bar, and 9 is the single-leg stirrup. Detailed Implementation

[0024] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the proposed structure for adding floors to existing concrete columns. The advantages and features of this utility model will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this utility model.

[0025] Please see the appendix Figure 1 and attached Figure 2A method for extending an existing concrete column by adding a new story includes first longitudinal reinforcement 1, second longitudinal reinforcement 3, and stirrups 4; several first longitudinal reinforcement 1 are located on the top outer side of the existing structural column 6, and several first longitudinal reinforcement 1 penetrate the excavated area of ​​the existing structural beam-slab 5 (the non-core area of ​​the existing beam-column joint); several second longitudinal reinforcement 3 are located on the top outer side of the existing structural column 6, and the lower ends of several second longitudinal reinforcement 3 are fixed within the existing structural beam-slab 5 (the core area of ​​the existing beam-column joint); several first longitudinal reinforcement 1 and several second longitudinal reinforcement 4 are used for the construction of an extension of an existing concrete column. All three longitudinal bars are arranged circumferentially around the top outer side of the existing structural column 6 (the second longitudinal bar 3 can be arranged around the outer side of the first longitudinal bar 1); the stirrups 4 are circumferentially connected around the outer side of several first longitudinal bars 1 and several second longitudinal bars 3, and several new column stirrups 4 are arranged vertically at intervals. The lower part of the first longitudinal bar 1, the lower part of the second longitudinal bar 3 and the stirrups 4 form a steel reinforcement system for the new column base with a cross section larger than that of the existing structural column 6 at the column head. The upper part of the first longitudinal bar 1 and the upper part of the second longitudinal bar 3 serve as the longitudinal bars of the new column.

[0026] By adding a new column base reinforcement system, a new column base is formed at the column head of the existing structural column 6 after formwork and concrete pouring. This base serves as an additional base for the new column, improving the connection strength between the new column and the existing structural column 6, ensuring the transfer of vertical loads, and without damaging the original structure.

[0027] The first longitudinal reinforcement 1 and the second longitudinal reinforcement 3 serve as both longitudinal reinforcement for the new column base and for the new column itself. The quantity, specifications, and spacing of the first longitudinal reinforcement 1 and the second longitudinal reinforcement 3 can be determined according to the load requirements of the new column. Since the first longitudinal reinforcement 1 and the second longitudinal reinforcement 3 are located outside the existing structural column 6, at the existing beam-column joint, the longitudinal reinforcement inevitably conflicts with the existing structural beam-slab 5. The second longitudinal reinforcement 3 at the conflicting location is shorter than the first longitudinal reinforcement 1 at the non-conflicting location. Furthermore, a combination is adopted in which the second longitudinal reinforcement 3 is fixedly connected to the existing structural beam-slab 5, and the first longitudinal reinforcement 1 penetrates the excavated area of ​​the existing structural beam-slab 5, thus taking into account both the arrangement of the longitudinal reinforcement of the new column and the avoidance of the core area of ​​the existing structural beam-slab 5.

[0028] Preferably, the cross-sectional dimensions of the new column base are larger than the cross-sectional dimensions of the existing structural column 6, and the new column base is 150mm larger on one side relative to the existing structural column 6.

[0029] Please see the appendix Figure 1 The lower end of the first longitudinal reinforcement 1 is bent toward the existing structural column 6 to form an L-shaped anchor bar 7, and the horizontal section of the L-shaped anchor bar 7 is anchored into the existing structural column 6.

[0030] By anchoring the horizontal section of the L-shaped anchor bar 7 into the existing structural column 6, the reliability and integrity of the connection between the new column base and the existing structural column 6 are improved.

[0031] The horizontal section of the L-shaped anchor bar 7 is anchored into the existing structural column 6 to a depth of not less than 150mm, and the depth of the first longitudinal bar 1 inserted into the new column base (i.e., the length below the top surface of the existing structural column 6) is 1.2×laE (the seismic anchorage length of the L-shaped anchor bar 7)×d (the diameter of the first longitudinal bar 1).

[0032] The anchoring depth of the L-shaped anchor bar 7 in the existing structural column 6 and the insertion depth in the new column base can be adaptively adjusted according to the actual load requirements.

[0033] Please see the appendix Figure 2 The stirrups 4 located within the height range of the existing structural beam slab 5 are composed of several segments of 7-shaped steel bars. The segments of 7-shaped steel bars pass through the holes opened on the existing structural beam slab 5 and are connected end to end to form a ring structure stirrups 4.

[0034] When the stirrup 4 conflicts with the existing structural beam and slab 5, through holes are drilled in the existing structural beam and slab 5 to allow the 7-shaped steel bars to pass through. Then, several sections of 7-shaped steel bars are connected end to end to form a ring structure stirrup 4, which covers the outside of the first longitudinal bar 1 and the second longitudinal bar 3.

[0035] Please see the appendix Figure 2 The stirrups 4 located outside the height range of the existing structural beams and slabs 5 are single-limb stirrups 9. The two ends of the single-limb stirrups 9 are tied and fixed to the first longitudinal reinforcement 1. Several single-limb stirrups 9 are circumferentially wrapped around the side of the existing structural column 6, and the intersection of two adjacent single-limb stirrups 9 are connected and fixed.

[0036] The single-leg stirrup 9 located below the top surface of the existing structural column 6 and the 7-shaped steel bars located within the height range of the existing structural beam and slab 5 serve as stirrups 4 for the new column base, while the single-leg stirrup 9 located above the top surface of the existing structural column 6 serves as stirrup 4 for the new column.

[0037] Taking an existing structural column 6 with a rectangular cross-section as an example, through holes are drilled in the four existing structural beams 5 around the existing structural column 6. Four sections of 7-shaped steel bars pass through the four existing structural beams 5 respectively, and then are connected end to end to form a rectangular ring of stirrups 4, which surround the outside of the existing structural column 6. Four single-leg stirrups 9 surround the four sides of the existing structural column 6.

[0038] Please see the appendix Figure 2 The existing structural beam slab 5 has several tie bars 8 embedded in its top and bottom, and these tie bars 8 are respectively tied and fixed to several second longitudinal bars 3.

[0039] By setting stirrups 4 and tie bars 8, the first longitudinal bar 1 and the second longitudinal bar 3 are connected to the existing beam-column joint, namely the existing structural column 6 and the existing structural beam-slab 5, to form a whole, thereby improving the integrity and connection strength of the new column base and the existing beam-column joint.

[0040] Please see the appendix Figure 1 An opening 2 is drilled on the top surface of the existing structural column 6, and the concrete of the new column base is filled into the opening 2, so that the existing structural column 6 and the new column base are connected into a whole.

[0041] By excavating opening 2, the mechanical interlocking force between the old and new concrete can be improved after the concrete for the new column base is poured.

[0042] Please see the appendix Figure 1 The lower end of the second longitudinal reinforcement 3 is anchored into the existing structural beam slab 5 and is staggered from the beam reinforcement in the existing structural beam slab 5.

[0043] The second longitudinal reinforcement 3 is anchored into the existing structural beam and slab 5 to improve the reliability and integrity of the connection between the new column base and the existing structural beam and slab 5, while avoiding the beam reinforcement in the existing structural beam and slab 5 to prevent damage to the existing structural beam and slab 5.

[0044] Please see the appendix Figure 1 and attached Figure 2 A construction method for adding floors to existing concrete columns includes the following steps:

[0045] Step 1: Initial layout and positioning: Determine the range of the existing structural beams and slabs to be removed and determine the boundaries of the new column bases.

[0046] Step 2: Concrete removal and interface treatment: Remove the concrete from the existing structural beams and slabs 5 within the area determined in Step 1, and roughen the interface between the existing structural columns 6 and the new column bases.

[0047] The roughened interface includes: the top surface of the existing structural column 6, the side surface of the existing structural column 6 within the height range of the newly added column base (i.e., the column side surface within the range of 1.2×laE×d below the top surface of the existing structural column 6), and the beam side surface of the area to be removed from the existing structural beam and slab 5.

[0048] By roughening the interface between the existing structural column 6 and the new column base, the mechanical interlocking force between the old and new concrete can be increased.

[0049] Step 3: Secondary layout and positioning: Accurately mark the anchorage position of the lower end of the second longitudinal reinforcement 3 on the existing structural beam slab 5, the perforation position of the stirrup 4 through the existing structural beam slab 5, and the anchoring position of the tie bar 8.

[0050] Step 4: Drill through holes in the existing structural beams and slabs 5 according to the perforation positions marked in Step 3, for subsequent perforation of the stirrups 4.

[0051] Step 5: Place the first longitudinal reinforcement 1 around the existing structural column 6 and through the excavated area of ​​the existing structural beam slab 5, and bend the lower end of the first longitudinal reinforcement 1 to form an L-shaped anchor bar 7, so that the horizontal section of the L-shaped anchor bar 7 is anchored into the existing structural column 6; place the second longitudinal reinforcement 3 around the existing structural column 6, and anchor the lower end of the second longitudinal reinforcement 3 into the existing structural beam slab 5 while avoiding the beam reinforcement in the existing structural beam slab 5.

[0052] When arranging the first longitudinal reinforcement 1, it is necessary to ensure that the depth of the first longitudinal reinforcement 1 inserted into the new column base, that is, the length below the top surface of the existing structural column 6, is 1.2×laE×d, to ensure that it is inserted in place. The horizontal section of the L-shaped anchor bar 7 is anchored into the existing structural column 6 to a depth of not less than 150mm. Under the premise of not changing the axial load transmission, the structural damage in the core area of ​​the existing beam-column joint is eliminated, and the microcracks are prevented from expanding due to the vibration of the chiseling, which affects the long-term durability of the structure.

[0053] By removing part of the concrete from the existing structural beam slab 5 in step 2, it is easier to lay the first longitudinal reinforcement 1, which passes through the floor slab in the non-core area of ​​the beam and column. For the core area of ​​the beam and column, i.e., the existing structural beam slab 5, the lower end of the second longitudinal reinforcement 3 is anchored into the existing structural beam slab 5, avoiding the beam reinforcement in the existing structural beam slab 5.

[0054] The combination of the first longitudinal reinforcement 1 and the second longitudinal reinforcement 3 can avoid drilling in the core area of ​​the existing beam-column joint and can successfully implant large-diameter anchor bars with a diameter of Φ20 or more.

[0055] Step 6: Insert several tie bars 8 into the top and bottom of the existing structural beam slab 5, and fix these tie bars 8 to several second longitudinal bars 3 respectively.

[0056] The depth to which the tie bar 8 is embedded in the existing structural beam slab 5 shall not be less than 15d2 (i.e., 15 times the diameter d2 of the tie bar 8).

[0057] Step 7: Install single-limb hoops 9 outside the height range of the existing structural beams and slabs 5. The two ends of the single-limb hoops 9 are tied and fixed to the first longitudinal reinforcement 1. Several single-limb hoops 9 are circumferentially wrapped around the side of the existing structural column 6, and the intersection of two adjacent single-limb hoops 9 are spot welded and fixed.

[0058] Step 8: Install stirrups 4 within the height range of the existing structural beam slab 5. Several 7-shaped steel bars pass through the through holes opened on the existing structural beam slab 5 and are connected end to end to form a ring structure stirrup 4.

[0059] In step 8, the single-sided welding length of two adjacent 7-shaped steel bars is not less than 10d1 (i.e., 10 times the diameter d1 of the 7-shaped steel bar).

[0060] Step 9: Erect the formwork for the new column base and pour concrete to form a new column base with a cross-section larger than that of the existing structural column, which will serve as the base for the construction of the new column.

[0061] In step 9, the concrete for the newly added column base is of a higher grade than that for the existing structural column 6.

[0062] The above description is only a description of the preferred embodiment of the present utility model and is not intended to limit the scope of the present utility model in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A method for adding floors to existing concrete columns, characterized in that, include: First longitudinal reinforcement (1), second longitudinal reinforcement (3), and stirrups (4); several first longitudinal reinforcements (1) are set on the top outer side of the existing structural column (6), and several first longitudinal reinforcements (1) penetrate through the excavated area of ​​the existing structural beam and slab (5); several second longitudinal reinforcements (3) are set on the top outer side of the existing structural column (6), and the lower ends of several second longitudinal reinforcements (3) are fixed inside the existing structural beam and slab (5); several first longitudinal reinforcements (1) and several second longitudinal reinforcements (3) are all along the existing structural column (6). The top outer perimeter is arranged; the stirrups (4) are circumferentially connected to the outside of several first longitudinal bars (1) and several second longitudinal bars (3), and several new column stirrups (4) are arranged vertically at intervals. The lower part of the first longitudinal bar (1), the lower part of the second longitudinal bar (3) and the stirrups (4) form a steel reinforcement system for the new column base with a cross section larger than that of the existing structural column (6) at the column head of the existing structural column (6). The upper part of the first longitudinal bar (1) and the upper part of the second longitudinal bar (3) serve as the longitudinal bars of the new column.

2. The structure for adding floors to existing concrete columns as described in claim 1, characterized in that, The lower end of the first longitudinal bar (1) is bent toward the existing structural column (6) to form an L-shaped anchor bar (7), and the horizontal section of the L-shaped anchor bar (7) is anchored into the existing structural column (6).

3. The structure for adding floors to existing concrete columns as described in claim 2, characterized in that, The horizontal section of the L-shaped anchor bar (7) is anchored into the existing structural column (6) to a depth of not less than 150mm, and the first longitudinal bar (1) is inserted into the new column base to a depth of 1.2×laE×d, where laE is the seismic anchorage length of the L-shaped anchor bar (7) and d is the diameter of the first longitudinal bar (1).

4. The structure for adding a story to an existing concrete column as described in claim 1, characterized in that, The stirrups (4) located within the height range of the existing structural beams (5) are composed of several sections of 7-shaped steel bars. The several sections of 7-shaped steel bars pass through the holes opened on the existing structural beams (5) and are connected end to end to form a ring structure stirrups (4). The stirrups (4) located outside the height range of the existing structural beams (5) are single-limb stirrups (9). The two ends of the single-limb stirrups (9) are tied and fixed to the first longitudinal reinforcement (1). Several single-limb stirrups (9) are circumferentially wrapped around the side of the existing structural column (6), and the intersection of two adjacent single-limb stirrups (9) is connected and fixed.

5. The structure for adding a story to an existing concrete column as described in any one of claims 1-4, characterized in that, The existing structural beam slab (5) has several tie bars (8) embedded at the top and bottom of the slab, and the tie bars (8) are respectively tied and fixed to several second longitudinal bars (3).

6. The structure for adding a story to an existing concrete column as described in claim 5, characterized in that, The existing structural column (6) has an opening (2) on its top surface. The concrete of the new column base is filled into the opening (2), so that the existing structural column (6) and the new column base are connected into a whole.

7. The structure for adding a story to an existing concrete column as described in claim 1, characterized in that, The lower end of the second longitudinal reinforcement (3) is anchored into the existing structural beam slab (5) and is staggered from the beam reinforcement in the existing structural beam slab (5).

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