A construction method for reinforced concrete columns using precast steel cages and UHPC formwork.

Abstract

This invention provides a precast steel cage and UHPC formwork for reinforced concrete columns and a construction method thereof. The reinforced concrete column includes a steel cage comprising multiple longitudinal bars and multiple stirrups spaced longitudinally on the longitudinal bars; it also includes multiple transverse bars and multiple UHPC formworks; the stirrups are welded to the longitudinal bars; multiple transverse bars are welded to each stirrup in the same horizontal direction, and the transverse bars on adjacent stirrups are arranged in different directions; the length of the transverse bars is greater than the outer dimension of the stirrups, and both ends of the transverse bars protrude outward to form protruding sections; the UHPC formwork is supported on the outer periphery of the steel cage before initial setting, and the protruding sections are inserted into the UHPC formwork; after the UHPC formwork solidifies, concrete is poured into it; UHPC has many advantages such as high strength, good durability and good impermeability, and using it as a permanent formwork for concrete columns can effectively prevent problems such as cracks and corrosion in the columns; at the same time, the connection between each UHPC formwork is a wet connection, which improves the integrity between the formworks and prevents grout leakage.

Description

Technical Field

[0001] This invention relates to the field of building technology, and more specifically, to a construction method for reinforced concrete columns using precast steel cages and UHPC formwork. Background Art

[0002] Reinforced concrete columns are suitable for various building structures, possessing numerous advantages such as high load-bearing capacity, good fire and corrosion resistance, and low cost, playing a vital role in engineering structures. However, compared to columns in other structures, they have a larger number of rebar tying points, making construction more complex. After tying the rebar cage, formwork must be erected on-site and concrete poured, followed by the removal of the formwork. This time-consuming and labor-intensive process significantly impacts the construction schedule. Furthermore, ordinary concrete has lower overall load-bearing capacity and ductility, and is prone to cracking. While using ultra-high performance concrete (UHPC) can overcome these drawbacks, its cost is significantly higher than that of ordinary concrete. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a construction method for reinforced concrete columns using precast steel cages and UHPC formwork to solve the above problems.

[0004] The present invention adopts the following solution:

[0005] This application provides a precast steel cage and UHPC formwork for a reinforced concrete column, including a steel cage comprising multiple longitudinal bars and multiple stirrups spaced longitudinally on the longitudinal bars; it also includes multiple transverse bars and multiple UHPC formwork; the stirrups are welded to the longitudinal bars; each stirrup has multiple transverse bars welded in the same horizontal direction, the transverse bars on adjacent stirrups are not in the same direction, and the transverse bars on spaced stirrups are in the same direction; the length of the transverse bars is greater than the outer dimension of the stirrups, and both ends of the transverse bars protrude outward to form protruding sections; the UHPC formwork is supported on the outer periphery of the steel cage before initial setting, and the protruding sections are inserted into the UHPC formwork; after the UHPC formwork solidifies, concrete is poured into it.

[0006] Furthermore, the steel cage is square, and each of the two adjacent stirrups is provided with a plurality of first transverse bars arranged along a first direction and a plurality of second transverse bars arranged along a second direction; the first direction is perpendicular to the second direction; and the protruding sections at both ends of the transverse bars are perpendicularly inserted into the UHPC template.

[0007] Furthermore, the first horizontal bar and the second horizontal bar are simultaneously welded onto the first stirrup at both ends of the steel cage.

[0008] Furthermore, it also includes a connecting cage for connecting the steel cage to another reinforced concrete column, which includes connecting cage longitudinal bars that correspond to and are staggered with the longitudinal bars of the steel cage, and four third transverse bars welded to the middle of the inner periphery of the connecting cage longitudinal bars.

[0009] A construction method for a reinforced concrete column includes the following steps:

[0010] S1: Prefabrication of steel cages, which involves welding longitudinal bars, stirrups, and transverse bars to form a column-shaped steel cage;

[0011] S2: Prefabrication of UHPC templates;

[0012] S3: The UHPC formwork and reinforcing cage are assembled using a horizontal casting method;

[0013] Assemble the UHPC templates obtained in step S2 before initial setting; hoist the precast steel cage from step S1 so that one side of it lies on the first UHPC template and insert the protruding section of that side into the first UHPC template; after the first UHPC template reaches the required solidification strength, hoist the steel cage so that the other side opposite the first UHPC template lies on the second UHPC template and insert the protruding section of that side into the second UHPC template; after the second UHPC template reaches the required solidification strength, hoist the steel cage so that the third side of it lies on the third UHPC template and insert the protruding section of that side into the third UHPC template; after the third UHPC template reaches the required solidification strength, hoist the steel cage so that the fourth side of it lies on the fourth UHPC template and insert the protruding section of that side into the fourth UHPC template; after the fourth UHPC template reaches the required strength, the factory prefabrication stage is completed.

[0014] S4: Pour concrete; transport the UHPC formwork and steel cage assembled in step S3 to the construction site, fix them, and then pour concrete into the UHPC formwork.

[0015] By adopting the above technical solution, the present invention can achieve the following technical effects:

[0016] Welding is performed at all connection points of the longitudinal bars and stirrups of the reinforcing cage, allowing the cage to bear loads independently. Multiple transverse bars are welded to the stirrups of the reinforcing cage to connect with the UHPC formwork, strengthening the overall integrity of the reinforcing skeleton. UHPC has numerous advantages such as high strength, good durability, and good impermeability; using it as permanent formwork for concrete columns effectively prevents cracking and corrosion. Furthermore, the connections between each UHPC formwork panel are wet connections, resulting in better overall integrity and preventing grout leakage. The entire reinforcing cage and UHPC formwork of the reinforced concrete column are prefabricated in the factory, allowing for direct pouring after hoisting into place on site. This eliminates the complex procedures of on-site rebar tying, formwork erection, and subsequent formwork removal, significantly reducing the on-site construction process. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the steel cage structure of a reinforced concrete column with a precast steel cage and UHPC formwork according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of a reinforced concrete column with precast steel cage and UHPC formwork after the horizontal bars have been welded.

[0020] Figure 3 This is a schematic diagram of the structure of a reinforced concrete column after the precast steel cage and the first UHPC formwork are assembled, according to an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of the structure of a reinforced concrete column after the precast steel cage and the second UHPC formwork are assembled, according to an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of the structure of a reinforced concrete column after the precast steel cage and UHPC formwork are assembled with a third UHPC formwork according to an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of the structure of a reinforced concrete column with a precast steel cage and a UHPC formwork according to an embodiment of the present invention, after the steel cage is assembled with the fourth UHPC formwork. Figure 1 ;

[0024] Figure 7 This is a schematic diagram of the structure of a reinforced concrete column with a precast steel cage and a UHPC formwork according to an embodiment of the present invention, after the steel cage is assembled with the fourth UHPC formwork. Figure 2 ;

[0025] Figure 8 This is a schematic diagram of the structure of a connecting cage for a precast steel cage and a UHPC formwork reinforced concrete column according to an embodiment of the present invention.

[0026] Figure 9 This is a partial structural diagram of the connection between two reinforced concrete columns and the connecting cage in an embodiment of the present invention;

[0027] Figure 10 This is a schematic diagram of the structure after two reinforced concrete columns are connected according to an embodiment of the present invention;

[0028] Icons: Longitudinal reinforcement 1, Stirrup 2, First transverse reinforcement 31, Second transverse reinforcement 32, UHPC formwork 4, Connecting cage longitudinal reinforcement 51, Third transverse reinforcement 52. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example

[0031] Combination Figures 1 to 10As shown, this embodiment provides a precast steel cage and UHPC formwork for a reinforced concrete column, including a steel cage comprising multiple longitudinal bars 1 and multiple stirrups 2 spaced longitudinally on the longitudinal bars 1; it also includes multiple transverse bars and multiple UHPC formwork; the stirrups 2 are welded to the longitudinal bars 1; each stirrup 2 has multiple transverse bars welded in the same horizontal direction, the transverse bars on two adjacent stirrups 2 are not in the same direction, and the transverse bars on two spaced stirrups 2 are in the same direction; the length of the transverse bars is greater than the outer dimension of the stirrup 2, and both ends of the transverse bars protrude outward to form protruding sections; the UHPC formwork is supported on the outer periphery of the steel cage before initial setting, and the protruding sections are inserted into the UHPC formwork; after the UHPC formwork solidifies, concrete is poured into it.

[0032] Weld all the connection points of the longitudinal bars 1 and stirrups 2 of the steel cage to allow the steel cage to bear the load independently; weld multiple transverse bars in multiple directions on the stirrups 2 of the steel cage to connect the UHPC formwork and strengthen the integrity of the steel cage; UHPC has many advantages such as high strength, good durability and good impermeability, and using it as a permanent formwork for concrete columns can effectively prevent the columns from cracking and corroding; at the same time, the connection between each UHPC formwork is a wet connection, which makes the integrity between the formwork better and prevents grout leakage.

[0033] Specifically, in this implementation, such as Figure 1 and Figure 2 As shown, the reinforcing cage is square, with two first transverse bars 31 arranged along a first direction and multiple second transverse bars 32 arranged along a second direction on two adjacent stirrups 2; the first direction is perpendicular to the second direction; and the protruding sections at both ends of the transverse bars are perpendicularly inserted into the UHPC template 4. The first transverse bars 31 and the second transverse bars 32 are simultaneously welded to the first stirrup 2 at both ends of the reinforcing cage to enhance the integrity of the reinforcing cage.

[0034] In this embodiment, as Figures 3 to 7As shown, the UHPC formwork 4 and the reinforcing cage are assembled and connected using a horizontal casting method. Specifically, before the prefabricated UHPC formwork 4 has initially set, the prefabricated reinforcing cage is hoisted so that one side of it lies horizontally on the first UHPC formwork 4, and the protruding section of that side is inserted into the first UHPC formwork 4. After the first UHPC formwork 4 has reached the required solidification strength, the entire assembly of the reinforcing cage and the first UHPC formwork 4 is hoisted so that the other side of the reinforcing cage opposite to the first UHPC formwork 4 lies horizontally on the second UHPC formwork 4, and the protruding section of that side is inserted into the second UHPC formwork 4. The assembly is completed after the second UHPC formwork 4 has reached the required solidification strength. Next, the reinforcing cage is assembled with the first and second UHPC formwork 4 and hoisted as a whole, so that the third side of the reinforcing cage lies upright on the third UHPC formwork 4, and the protruding section of this side is inserted into the third UHPC formwork 4. After the third UHPC formwork 4 reaches the required solidification strength, the reinforcing cage is then assembled with the first, second, and third UHPC formwork 4 and hoisted as a whole, so that the fourth side of the reinforcing cage lies upright on the fourth UHPC formwork 4, and the protruding section of this side is inserted into the fourth UHPC formwork 4. After the fourth UHPC formwork 4 reaches the required strength, the factory prefabrication stage is completed. By using factory prefabrication to make the entire reinforcing cage and UHPC formwork 4 of the reinforced concrete column into a whole, it can be directly poured after being hoisted into place on the construction site, eliminating the complicated procedures of on-site reinforcement binding, formwork erection, and subsequent formwork removal, greatly reducing the on-site construction process.

[0035] Furthermore, such as Figures 8 to 10 As shown, the system also includes a connecting cage for connecting another reinforced concrete column. This connecting cage includes longitudinal reinforcing bars 51 that correspond to and are staggered with the longitudinal reinforcing bars 1 of the reinforced concrete column, and four third transverse reinforcing bars 52 welded to the inner circumference of the longitudinal reinforcing bars 51. The connecting cage is used to connect two reinforced concrete columns. During assembly, the longitudinal reinforcing bars 51 on both sides of the third transverse reinforcing bars 52 are placed in the reinforced concrete columns of the upper and lower columns, respectively. The longitudinal reinforcing bars 51 overlap with the longitudinal reinforcing bars 1 of the reinforced concrete column, and the third transverse reinforcing bars 52 are supported on the first transverse reinforcing bars 31 or the second transverse reinforcing bars 32. After assembly, the UHPC formwork 4 of the upper and lower reinforced concrete columns are joined together, and finally, concrete is poured inside the UHPC formwork 4.

[0036] The following details the construction method for this reinforced concrete column, including the following steps:

[0037] S1: Prefabrication of the steel cage, which involves welding longitudinal bars 1, stirrups 2 and transverse bars to form a column-shaped steel cage;

[0038] S2: Prefabricated UHPC template 4;

[0039] S3: The UHPC formwork 4 and the reinforcing cage are assembled using a horizontal casting method;

[0040] Assemble the UHPC template 4 prefabricated in step S2 before initial setting; hoist the prefabricated steel cage in step S1 so that one side of it lies upright on the first UHPC template 4, and insert the protruding section of that side into the first UHPC template 4; after the first UHPC template 4 reaches the required solidification strength, hoist the steel cage so that the other side opposite to the first UHPC template 4 lies upright on the second UHPC template 4, and insert the protruding section of that side into the second UHPC template 4; after the second UHPC template 4 reaches the required solidification strength, hoist the steel cage so that the third side of it lies upright on the third UHPC template 4, and insert the protruding section of that side into the third UHPC template 4; after the third UHPC template 4 reaches the required solidification strength, hoist the steel cage so that the fourth side of it lies upright on the fourth UHPC template 4, and insert the protruding section of that side into the fourth UHPC template 4; after the fourth UHPC template 4 reaches the required strength, the factory prefabrication stage is completed.

[0041] S4: Pour concrete; transport the UHPC formwork 4 and steel cage assembled in step S3 to the construction site, fix them, and then pour concrete into the UHPC formwork 4.

[0042] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are 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 operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

Claims

1. A construction method for a reinforced concrete column using a precast steel cage and UHPC formwork, the reinforced concrete column comprising a steel cage including multiple longitudinal bars and multiple stirrups evenly distributed along the longitudinal direction on the longitudinal bars; characterized in that, It also includes multiple horizontal reinforcing bars and multiple UHPC formwork panels; the stirrups are welded to the longitudinal reinforcing bars; each stirrup has multiple horizontal reinforcing bars welded along the same horizontal direction, the horizontal reinforcing bars on two adjacent stirrups are not in the same direction, and the horizontal reinforcing bars on two stirrups that are spaced apart are in the same direction; the length of the horizontal reinforcing bars is greater than the outer dimension of the stirrups, and both ends of the horizontal reinforcing bars protrude outward to form protruding sections; the UHPC formwork panels are supported on the outer periphery of the reinforcing cage before initial setting, and the protruding sections are inserted into the UHPC formwork panels; after the UHPC formwork panels solidify, concrete is poured into them; The construction method includes the following steps: S1: Prefabrication of steel cages, which involves welding longitudinal bars, stirrups, and transverse bars to form a column-shaped steel cage; S2: Prefabrication of UHPC templates; S3: The UHPC formwork and reinforcing cage are assembled using a horizontal casting method; Assemble the UHPC templates obtained in step S2 before initial setting; hoist the precast steel cage from step S1 so that one side of it lies on the first UHPC template and insert the protruding section of that side into the first UHPC template; after the first UHPC template reaches the required solidification strength, hoist the steel cage so that the other side opposite the first UHPC template lies on the second UHPC template and insert the protruding section of that side into the second UHPC template; after the second UHPC template reaches the required solidification strength, hoist the steel cage so that the third side of it lies on the third UHPC template and insert the protruding section of that side into the third UHPC template; after the third UHPC template reaches the required solidification strength, hoist the steel cage so that the fourth side of it lies on the fourth UHPC template and insert the protruding section of that side into the fourth UHPC template; after the fourth UHPC template reaches the required strength, the factory prefabrication stage is completed. S4: Pour concrete; transport the UHPC formwork and steel cage assembled in step S3 to the construction site, fix them, and then pour concrete into the UHPC formwork.

2. The construction method of the reinforced concrete column with precast steel cage and UHPC formwork according to claim 1, characterized in that, The steel cage is square, and each of the two adjacent stirrups is provided with a plurality of first horizontal bars arranged along a first direction and a plurality of second horizontal bars arranged along a second direction; the first direction is perpendicular to the second direction; and the protruding sections at both ends of the horizontal bars are perpendicularly inserted into the UHPC template.

3. The construction method of the reinforced concrete column with precast steel cage and UHPC formwork according to claim 2, characterized in that, The first horizontal bar and the second horizontal bar are welded to the first stirrup at both ends of the steel cage.

4. The construction method of the reinforced concrete column with precast steel cage and UHPC formwork according to claim 1, characterized in that, It also includes a connecting cage for connecting the steel cage to another reinforced concrete column, which includes connecting cage longitudinal bars that correspond to and are staggered with the longitudinal bars of the steel cage, and four third transverse bars welded to the middle of the inner periphery of the connecting cage longitudinal bars.

Images