Construction method of large-diameter circular shaped steel reinforced concrete inclined column

Abstract

The present application belongs to the technical field of building engineering, and particularly relates to a construction method of a large-diameter circular steel reinforced concrete inclined column. The method comprises the steps of space positioning of the to-be-installed inclined column, installation and welding of the inclined column steel, setting of the inclined column steel bars, setting of a pouring circular mold and segmented pouring. The construction method of the large-diameter circular steel reinforced concrete inclined column provided by the present application effectively shortens the construction process flow of the existing steel inclined column through a segmented construction method and a brand-new circular mold device and its installation method. The construction method is simple to operate, economical and reasonable, and high in safety, and provides a new construction route for the existing large-diameter circular steel reinforced concrete inclined column and a reference for similar projects.

Description

Technical Field

[0001] This invention belongs to the field of building engineering technology, specifically relating to a construction method for a large-diameter circular steel-concrete inclined column. Background Technology

[0002] In public buildings such as stadiums and theaters where the space and shape are easily variable, inclined and large-diameter circular steel-concrete composite columns are often used as vertical load-bearing components to meet load-bearing capacity and shape requirements. In the construction of inclined columns, the spatial positioning and connection of the steel profiles, as well as the connection and binding of the reinforcing bars, are challenging aspects. For large-diameter concrete columns, the construction of scaffolding support systems, the use of large-diameter circular molds, and the pouring of large volumes of concrete are also major challenges. In particular, the processing, connection, and dismantling of formwork present numerous technical problems. For example, traditional steel molds are heavy, increasing the difficulty of hoisting and installation, and making demolding difficult. The inclined column shape results in an angled contact surface between the ends of existing steel molds and the bottom surface of the beams and slabs, requiring custom-made steel mold end dimensions and increasing labor hours during installation, while also resulting in unsatisfactory molding effects. Using lightweight PVC formwork can lead to insufficient strength, making it prone to bulging and cracking during large-volume concrete pouring.

[0003] Providing a method for constructing large-diameter circular steel-concrete inclined columns is a technical problem that urgently needs to be solved in engineering. Summary of the Invention

[0004] This invention provides a construction method for large-diameter circular steel-concrete inclined columns. Through segmented construction and a novel circular formwork device and its installation method, the existing construction process for steel inclined columns is effectively shortened. This construction method is simple to operate, economical, and highly safe, providing a new construction route for existing large-diameter circular steel-concrete inclined columns and serving as a reference for similar projects.

[0005] The technical solution adopted in this invention is as follows:

[0006] A construction method for a large-diameter circular steel-concrete inclined column, wherein the large diameter refers to the outer diameter of the steel section being in the range of 2 to 3 meters, the method comprising the following steps:

[0007] S1. Spatial positioning of the inclined column to be installed: Based on the design requirements and the current site conditions, determine the positions of the two ends of the inclined column to be installed at the center points of the horizontal plane of the respective floors and the projected boundary lines, thereby determining the slope of the inclined column to be installed and the required formwork range;

[0008] S2. Installation and welding of inclined steel columns: The steel columns are set along the axis of the inclined columns to be installed. The steel columns are manufactured and hoisted in sections according to the number of floors and floor height. The steel columns are welded to the corresponding floor level to form a whole. The welding position is 1m above the floor level of the floor.

[0009] S3. Setting the inclined column reinforcement: The inclined column reinforcement is the cast-in-place skeleton of the inclined column to be installed, including longitudinal bars and stirrups. The longitudinal bars are set along the position of the inclined column to be installed and are constructed in sections according to the floor. The stirrups pass through the steel section and are connected by the steel sleeve extrusion connection method. The stirrups are tied and fixed to the longitudinal bars. In this step, the connection method of the longitudinal bars, stirrups and steel section holes can be constructed with reference to the existing technology.

[0010] S4. Setting up the casting circular mold: The circular mold is installed in sections. According to the section length and radius of the inclined column to be installed, the plywood is first bent and fixed into a semicircle. Then, two semicircular pieces of plywood are spliced ​​together at the position of the inclined column to be installed, i.e., the outer perimeter of the inclined column reinforcement, to form a section of the circular mold.

[0011] S5. Segmented casting: Concrete is poured into the segmented circular mold to form a segment of the inclined column to be installed;

[0012] S6. After the concrete to be poured has solidified, remove the segmented circular formwork. According to the requirements of the inclined column to be installed, repeat steps S4-S5 to continue setting and pouring the circular formwork for the next segment until the entire inclined column to be installed is poured.

[0013] Preferably, in step S4, the circular molds are joined using a tongue-and-groove joint, with the joints of the circular molds being machined with concave and convex tongues respectively, and then joined using the tongue-and-groove joint.

[0014] Preferably, a steel hoop is provided around the periphery of the assembled circular mold. The steel hoop is arranged in a circle perpendicular to the splicing interface of the circular mold, which is used to further tighten and close the circular mold.

[0015] Preferably, the steel hoop is 10cm wide, the opening of the steel hoop is connected by a fixing clip, the distance between adjacent steel hoops is 30cm, and the opening positions of adjacent steel hoops are staggered.

[0016] Preferably, a steel nail is also provided below the steel hoop to prevent the steel hoop from sliding down.

[0017] Preferably, the circular mold is segmented according to the floor height. When the length of the inclined column to be installed in a single floor is greater than the maximum length of the circular mold, multiple circular molds are spliced ​​together to form a complete circular mold segment within that floor.

[0018] Preferably, the upper and lower parts of the circular mold are spliced ​​in a staggered manner. In this case, the position of the steel hoop should be such that at least one steel hoop is provided in the middle section of each semi-circular plywood piece.

[0019] Preferably, the concrete used for casting is self-compacting concrete, and the concrete in each segment of the circular mold is cast in layers.

[0020] Preferably, the steel section is a cross-shaped steel section. After the concrete is poured, if there is a bent part in the steel section, a vibrator is inserted into the space between the flange, web and the circular mold of the steel section at the bent part to vibrate and ensure the filling of concrete.

[0021] The aforementioned curved sections refer to the possible changes in the slope of the inclined columns to be installed, such as columns that are upright on the first floor and inclined columns on the second floor and above, or other common variations that may occur in other projects.

[0022] Preferably, step S4 further includes building a scaffolding support system, specifically: according to the floor segmentation, a circular mold is first set up on each floor, and then scaffolding is built to support the circular mold.

[0023] The beneficial effects of this invention are as follows:

[0024] In the construction of ordinary reinforced concrete columns, it is difficult to control the quality of large-diameter columns in terms of casting and forming, and problems such as local bulging and poor flatness are likely to occur. Round columns, unlike square columns, are prone to grout leakage during formwork splicing, and the hoisting and splicing of long steel sections are also difficult to refer to as the overall hoisting of ordinary column reinforcement.

[0025] This invention provides a complete construction method for large-diameter steel-concrete inclined cylindrical columns. By tying the reinforcing bars floor by floor and pouring concrete in layers, the improved column formwork system ensures stability and avoids bulging caused by improper reinforcement methods, significantly improving the flatness of the column during subsequent construction. This invention also innovates a segmented construction method, effectively solving problems related to steel hoisting and welding.

[0026] A novel wooden circular formwork device is adopted, which boasts high resistance to expansion pressure, flexible assembly, and ensures a good appearance at beam-column joints. The wooden formwork uses tongue-and-groove splicing, effectively preventing concrete overflow and improving the overall integrity of the pouring. Furthermore, the circular formwork is equipped with convenient steel hoops and clips, reducing the lateral pressure exerted by the concrete's own weight on the wooden formwork and preventing cracking. This invention provides a construction method that effectively shortens the existing construction process for inclined steel columns. This construction method is simple to operate, economical, and highly safe, providing a new construction route for existing large-diameter circular steel-concrete inclined columns and serving as a reference for similar projects. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings.

[0028] Figure 1 This is a front view schematic diagram of the installation of a circular steel-concrete inclined column in an embodiment;

[0029] Figure 2 for Figure 1The cross section A-A' shows the cross-shaped steel section and the reinforcing bars of the inclined column;

[0030] Figure 3 Schematic diagram of segmented scaffolding erected for circular steel-concrete inclined columns;

[0031] Figure 4 for Figure 3 The enlarged view at point II shows the details of the steel hoops and nails around the circular mold and the scaffolding erected.

[0032] Figure 5 for Figure 1 The enlarged view at point I shows the details of setting up transverse reinforcing steel strips and longitudinal reinforcing short steel bars after the circular mold was cast;

[0033] Figure 6 for Figure 2 The enlarged view at point III shows the splicing tongue and groove structure of the circular mold;

[0034] Figure 7 for Figure 2 The enlarged view at point IV shows the connecting snap-fit ​​structure of the steel hoop;

[0035] The meanings of the symbols marked in the figure are as follows:

[0036] 10- Inclined column 11- Steel section 12- Longitudinal reinforcement 13- Stirrups 14- Floor

[0037] 20-Circular mold 21-Steel hoop 22-Fixing clip 23-Steel nail

[0038] 30-Scaffolding 31-Uprights 32-Horizontal Bars 33-Tie Bars 34-Diagonal Bars

[0039] 41-Reinforcing steel strips; 42-Reinforcing short reinforcing bars Detailed Implementation

[0040] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0041] Example 1

[0042] A construction project in Changshi City has a total building area of ​​70,030 square meters, with one underground floor and three floors above ground. The main structure is a frame structure and a steel structure. Most of the columns in the building are designed with diameters of 1.5m and 2m, and are large-diameter circular steel-concrete inclined columns.

[0043] The irregular contact surface between the formwork and the beam / slab of extra-large diameter inclined cylindrical columns significantly increases the difficulty of formwork construction compared to ordinary cylindrical or square columns. If traditional steel formwork is used, the formwork is heavy during construction, increasing the difficulty of hoisting and installation, and the steel formwork is difficult to demold. It generally needs to be repaired after three uses. Finally, the contact surface between the inclined column steel formwork and the beam / slab is irregularly cut, and the forming effect is not ideal. If PVC formwork or strip formwork is used, the strength is insufficient, and it is easy to burst under the self-weight of large volume concrete.

[0044] like Figure 1-7 As shown, the specific construction steps for a certain inclined column 10 to be installed using the construction method provided by this invention are as follows:

[0045] S1. Spatial positioning of the inclined column 10 to be installed: Based on the construction drawings and the original coordinate points on site, GPS is used to determine the center point position and projection boundary line of the two ends of the inclined column 10 on the horizontal plane of different floors 14, and to implement the control of the inclination of the inclined column 10 and the range of the circular mold 20, so as to achieve accurate positioning.

[0046] S2. Installation and welding of inclined steel section 11: The steel section 11 is set along the axis of the inclined column 10 to be installed, ensuring that the axis of the steel section 11 coincides with the axis of the inclined column 10 to be installed. The steel section 11 to be installed is fabricated and hoisted in sections according to the number of floors and floor height, and welded together at a position 1m above the floor level of the corresponding floor.

[0047] S3. Setting the inclined column reinforcement: The inclined column reinforcement includes longitudinal bars 12 and stirrups 13. According to the design drawings, the longitudinal bars 12 and stirrups 13 of the column are cut and constructed. The longitudinal bars 12 are constructed in sections according to the floors 14. In this embodiment, the inclined column 10 to be installed is inclined as a whole from the first floor. Therefore, the slope of the reinforcement between different floors 14 is the same, and sleeves are used for direct connection. If the inclined column implemented has a part that is vertical on the first floor, a hydraulic press is used to bend the longitudinal bars 12 according to the slope of the inclined column before connecting them with sleeves.

[0048] Based on the edge line and protective layer thickness of the inclined column 10 to be installed, first, the stirrups 13 are fitted onto the extended longitudinal bars 12 of the already cast column and the longitudinal bars 12 are fixed, ensuring that the column longitudinal bars 12 are fixed according to the designed slope, and the spacing of the stirrups 13 is adjusted. After the longitudinal bars 12 are erected, mechanical connection joints and sleeves are used to connect the ends of the extended longitudinal bars 12 in the already cast column to the longitudinal bars 12 that are about to be tied. Holes are pre-drilled in the steel section 11 in the column, and when tying the longitudinal bars 12, some of the stirrups 13 need to pass through the pre-drilled holes to form an integral whole with the steel section 11.

[0049] S4. Setting up the casting circular mold 20: Constructing the formwork for the inclined columns to be installed for casting. The circular mold 20 is made of 15mm thick plywood, with each piece measuring 1.5-1.8m in length. Figure 2As shown, the circular mold 20 is set on the outside of the inclined column reinforcement. In this embodiment, the length of the inclined column 10 to be installed in a single floor 14 is greater than the maximum length of the circular mold 20. The circular mold 20 is segmented and installed according to the floor 14, and a complete circular mold segment within the floor 14 is formed by splicing multiple circular molds 20 together.

[0050] First, bend and fix the plywood into a semi-circle according to the radius of the inclined column 10 to be installed. Then, assemble two semi-circular plywood pieces at the position of the inclined column 10 to form a segment of the circular mold 20. During installation, the upper and lower splices of the circular mold 20 are staggered, that is, to ensure that the adjacent upper and lower semi-circular template segments are installed in a staggered manner, and the horizontal seams are aligned.

[0051] In particular, such as Figure 6 As shown, the template interface is machined into a tongue-and-groove shape with concave and convex joints, and the left and right templates interlock longitudinally. Align the tongue-and-groove joints of the templates according to the template positioning lines, and then use steel hoops 21 to tighten and close the templates.

[0052] The aforementioned steel hoop 21 is arranged in a circle perpendicular to the splicing interface of the circular mold 20 to further tighten and close the circular mold 20, preventing it from cracking and failing due to the expansion of concrete during pouring. In this embodiment, the steel hoop 21 is 10cm wide, and the opening of the steel hoop 21 is connected by a fixing clip 22. The distance between adjacent steel hoops 21 is 30cm, and the opening positions of adjacent steel hoops 21 are staggered. Furthermore, at least one steel hoop 21 is provided in the middle section of each semi-circular plywood piece.

[0053] To prevent the steel hoops 21 from slipping, steel nails 23 are also installed below each steel hoop 21. For example... Figure 7 As shown, the fixing clip 22 is connected by a pull rod and bolts. During installation, the tightness of the steel hoop 21 can be adjusted by adjusting the nuts on the left and right sides.

[0054] S4. Setting up the scaffolding 30 support system: The scaffolding 30 can be erected according to existing technology. The difference is that in this embodiment, the scaffolding 30 is implemented in sections according to the height of floor 141. For each floor, the circular mold 20 is first set up, and then the scaffolding 30 is erected. The scaffolding 30 includes uprights 31, horizontal bars 32, tie rods 33, and diagonal braces 34. The uprights 31 and horizontal bars 32 are arranged vertically to form the scaffolding foundation. The tie rods 33 are fixed above the horizontal bars 32 that are perpendicular to each other on the same horizontal plane and are close to the circular mold 20 template, which plays the role of supporting the inclined template. The diagonal braces 34 are fixed in the center of the tie rods 33 and extend at a suitable angle to the floor where the inclined column 10 is to be installed, which plays the role of supporting the stability of the template.

[0055] S5. Segmented Casting: Concrete is poured into the circular mold 20 of the segment to form a segment of the inclined column to be installed. The concrete is poured in segments according to floor 14, and each segment of concrete should be poured in layers within the pre-assembled formwork. The free fall height of the concrete from the bucket opening should not exceed 2m. The next layer of concrete should be poured before the initial setting of the previous layer. After the self-compacting concrete is poured, according to the shape of the steel section 11 in the column, vibrators are inserted into the concrete in the gaps between the flanges, webs and formwork of the steel section 11, and extended to the bottom of the column for vibration to ensure that the concrete flows to all parts of the column.

[0056] S6. After the concrete to be poured has solidified, remove the segmented circular formwork 20 and scaffolding 30. According to the requirements of the inclined column 10 to be installed, repeat steps S4-S5 to continue the construction and pouring of the next segment of circular formwork 20 and scaffolding 30 until the entire inclined column 10 to be installed is poured.

[0057] like Figure 5 As shown, after pouring, the outer side of the circular mold 20 is also equipped with reinforcing steel strips 41 and reinforcing short steel bars 42. The reinforcing short steel bars 42 are parallel to the axial direction of the inclined column 10 to be installed and are set tightly against the circular mold 20. The reinforcing steel strips 41 are perpendicular to the axial direction of the inclined column 10 to be installed and are set around the outer circle of the reinforcing short steel bars 42. The reinforcing steel strips 41 and reinforcing short steel bars 42 are used to prevent the formwork joints from cracking and failing due to the expansion of the poured concrete.

[0058] Compared to ordinary reinforced concrete columns, the construction process for this inclined column 10 utilizes wooden cylindrical formwork, eliminating common quality defects such as water seepage, air bubbles, and cracks on the concrete surface, thus enhancing the appearance quality of the concrete and resulting in significant overall benefits. Compared to traditional steel formwork, it is lighter in weight and can be moved and positioned by 2-3 workers on the working level, without the need for vertical transportation machinery (tower cranes). The finished inclined column has a smooth surface, small and inconspicuous joints, standard dimensions, and is inclined at the designed angle without any grout leakage.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A construction method for a large-diameter circular steel-concrete inclined column, characterized in that, The outer diameter of the large-diameter finger-shaped steel is in the range of 2~3m. The method includes the following steps: S1. Spatial positioning of the inclined column to be installed: Based on the design requirements and the current site conditions, determine the positions of the two ends of the inclined column to be installed at the center points of the horizontal plane of their respective floors and the projected boundary lines, thereby determining the slope of the inclined column to be installed and the required formwork range; S2. Installation and welding of inclined steel columns: The steel columns are set along the axis of the inclined columns to be installed. The steel columns are manufactured and hoisted in sections according to the number of floors and floor height. The steel columns are welded to the corresponding floor level to form a whole. The welding position is 1 m above the floor level of the floor. S3. Setting the inclined column reinforcement: The inclined column reinforcement includes longitudinal bars and stirrups. The longitudinal bars are set along the position of the inclined column to be installed and are constructed in sections according to the floor. The stirrups pass through the steel section and are connected by the steel sleeve extrusion connection method. The stirrups are tied and fixed to the longitudinal bars. S4. Setting up the casting circular mold: The circular mold is installed in sections. According to the section length and radius of the inclined column to be installed, the plywood is first bent and fixed into a semicircle. Then, two semicircular pieces of plywood are spliced ​​together at the position of the inclined column to be installed, i.e., the outer perimeter of the inclined column reinforcement, to form a section of the circular mold. It also includes the construction of a scaffolding support system, specifically: according to the floor division, a circular mold is first set up on each floor, and then scaffolding is built to support the circular mold; the scaffolding includes uprights, horizontal bars, tie rods and diagonal braces. The uprights and horizontal bars are arranged vertically to form the scaffolding foundation; the tie rods are fixed above the horizontal bars that are perpendicular to each other on the same horizontal plane and are close to the circular mold template, so as to support the inclined template; the diagonal braces are fixed in the center of the tie rods and extend to the floor where the inclined column is to be installed, so as to support the stability of the template; S5. Segmented casting: Concrete is poured into the segmented circular mold to form a segment of the inclined column to be installed; S6. After the concrete to be poured has solidified, remove the segmented circular formwork. According to the requirements of the inclined column to be installed, repeat steps S4-S5 to continue setting and pouring the circular formwork for the next segment until the entire inclined column to be installed is poured.

2. The construction method of a large-diameter circular steel-concrete inclined column as described in claim 1, characterized in that: In step S4, the circular molds are joined using a tongue and groove interlocking method. The joints of the circular molds are respectively machined with "concave" and "convex" tongues and grooves, and then joined together using the tongue and groove interlocking method.

3. The construction method for a large-diameter circular steel-concrete inclined column as described in claim 2, characterized in that, The assembled circular mold is also surrounded by steel hoops, which are set perpendicular to the joint of the circular mold to further tighten and close the circular mold.

4. The construction method for a large-diameter circular steel-concrete inclined column as described in claim 3, characterized in that, The steel hoop is 10cm wide, and the opening of the steel hoop is connected by a fixing clip. The distance between adjacent steel hoops is 30cm, and the opening positions of adjacent steel hoops are staggered.

5. The construction method for a large-diameter circular steel-concrete inclined column as described in claim 3, characterized in that, Steel nails are also installed below the steel hoop to prevent it from slipping down.

6. The construction method of a large-diameter circular steel-concrete inclined column as described in claim 3, characterized in that: The circular mold is segmented according to the floor height. When the length of the inclined column to be installed in a single floor is greater than the maximum length of the circular mold, multiple circular molds are spliced ​​together to form a complete circular mold segment within that floor.

7. The construction method of a large-diameter circular steel-concrete inclined column as described in claim 6, characterized in that: The upper and lower parts of the circular mold are spliced ​​in a staggered manner. At this time, the position of the steel hoop should be such that at least one steel hoop is set in the middle section of each semi-circular plywood piece.

8. The construction method for a large-diameter circular steel-concrete inclined column as described in claim 1, characterized in that, The concrete used for pouring is self-compacting concrete, and the concrete in each segment of the circular mold is poured in layers.

9. The construction method of a large-diameter circular steel-concrete inclined column as described in claim 8, characterized in that, The steel section is a cross-shaped steel section. After the concrete is poured, if there is a bent part of the steel section, a vibrator is inserted into the space between the flange, web and the circular mold of the steel section at the bent part to ensure the filling of concrete.

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