Opposite insertion construction method for steel molds of two-layer frame columns of multi-layer factory building

Abstract

The invention provides a multi-storey plant two-storey frame column steel mould opposite insertion construction method which comprises the following steps: firstly, establishing a construction scheme offsetting group before two-storey frame column construction, checking data to determine a frame column and a hoisting machine which adopt steel mould opposite insertion, hoisting a steel reinforcement cage into a steel mould after the steel reinforcement cage is bound, and hoisting the steel reinforcement cage into the steel mould; after the steel mold is assembled, the steel mold and the reinforcement cage are integrally hoisted and installed to the position of the frame column to be fixed, and finally frame column concrete pouring, steel mold dismantling and frame column film covering maintenance are conducted. The problems that due to the fact that a column reinforcement cage is twisted and inclined due to the large dead weight, a formwork is difficult to reinforce, and the concrete pouring forming quality is poor are solved, an ultrahigh operation scaffold body needing to be erected for reinforcing steel bar installation and formwork reinforcement is omitted, materials for installing and detaching a plate buckle scaffold are saved, meanwhile, potential safety hazards of an ultrahigh frame body are avoided, and the construction period is shortened. And the forming quality of the concrete structure is also ensured through the construction method of oppositely inserting the steel column formworks.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction, and in particular relates to a method for inserting steel formwork for second-floor frame columns of a multi-story factory building. Background Art

[0002] With the rapid development of e-commerce and the deepening of global trade, the logistics and warehousing industry has become an indispensable key link in the modern economic system. As the scale of urban development continues to expand, land resources are becoming increasingly scarce, and industrial land is in short supply. In order to solve these problems, "industrial upstairs" has become a new industrial carrier space model. The traditional frame structure construction method will cause the following problems: (1) When tying the steel bars of the second-floor frame columns, it is necessary to set up an operating scaffolding with a height of more than 10m in advance, which poses a great safety hazard and construction cost; (2) The height of the second-floor frame columns is relatively high, and the column steel cage is twisted and tilted due to its heavy deadweight, which makes it difficult to reinforce the formwork and the quality of concrete pouring is poor. In summary, the construction difficulties of the second-floor frame column steel bar installation and formwork reinforcement of multi-story factory buildings, and how to avoid the safety hazards caused by the installation and removal of super-high operating scaffolding have become problems that need to be solved urgently. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a method for inserting steel formwork into the second-floor frame columns of a multi-story factory building, thereby solving construction technical problems with great safety hazards such as installation and disassembly of super-high operating frames, installation of steel cages, and reinforcement of formwork during the construction stage of the second-floor frame columns of a multi-story factory building.

[0004] The present invention achieves the above technical objectives through the following technical means.

[0005] A method for inserting steel formwork for second-floor frame columns of a multi-story factory building, comprising the following steps: Step 1: Consult the data to determine the second-floor frame columns that can be overlapped with column reinforcement, and determine the lifting machinery and lifting plan; Step 2: Binding of steel cages for second-floor frame columns; Step 3: Assemble the steel column formwork; Step 4: Use mortar to level the bottom of the steel column mold to form a mortar leveling layer; Step 5: Hoisting and inserting the steel column formwork; Step 6: Concrete pouring of second-floor frame columns; Step 7: Removal of steel column formwork Step 8: Cover and maintain the second-floor frame columns.

[0006] Furthermore, in step 2, a mobile binding frame is used to bind the steel bars, and the steel bars are directly lifted after binding. A wooden board is placed at the lower end of the binding frame column to prevent the column from sinking and causing deformation of the steel cage. The protective layer is welded and positioned using tic-tac-toe positioning bars. One tic-tac-toe positioning bar is arranged every two meters. The steel bars at the lifting point extend out of the steel cage, and threaded steel bars are also welded in the other direction, but do not need to extend out of the steel cage. A concrete pouring port is reserved in the middle PVC casing of the steel cage, and at least two diagonal holes for vibration rods are reserved.

[0007] Furthermore, the specific process of step 3 is as follows: Step 3.1: Place a U-shaped steel column mold flat on the ground, place square wood under the steel column mold, adjust the inclination of the square wood, and reduce the distortion of the steel column mold; Step 3.2: Before each use of the steel column formwork, clean the cement and rust on the surface, and apply oily release agent after cleaning, except for the joints. Foam strips are pasted at the joints and special-shaped transitions; Step 3.3: Use a truck crane to lift the tied steel cage into the steel column mold; Step 3.4: Close the steel column mold; first check whether the mold is deformed, check the flatness of the joints to prevent leakage; then put a U-shaped mold upside down on the lower U-shaped mold, use a crowbar to align it with the bolt holes of the column mold, slowly put it in place, first insert the first bolt at both ends and tighten it initially, then adjust the horizontality of the lower U-shaped mold and insert all the bolts at the same time, and finally tighten it symmetrically from both sides of one end.

[0008] Furthermore, the specific process of step 5 is as follows: Step 5.1: The main hook and the auxiliary hook rise simultaneously to lift the steel column formwork off the ground, and the main hook is lifted to lift the steel column formwork to a vertical state. To prevent the steel wire from colliding with the tool-type guardrail, the main hook is hung with a crossbar to connect with the upper end of the steel column formwork; Step 5.2: The overlap percentage of the steel cage in the steel column mold and the reserved steel bars of the second floor frame column is 50%, and the overlap length is 1.4LaE; the stirrups in the overlap section are welded closed stirrups, and the overlap part is the inner stirrup reinforcement; Step 5.3: When the crane loosens the wire rope but does not unhook it, tie the wire ropes on the four sides of the steel column formwork to the pre-buried lifting rings on the floor through a tensioner or hoist. Use a theodolite or a plumb bob hung on the steel column formwork to check the verticality and adjust the tensioners in each direction. After confirming the verticality, tighten the tensioners. Furthermore, the specific process of step 7 is as follows: Step 7.1: Removal of the wedge-shaped formwork at the foot: Loosen the cable wind rope 24 hours after the concrete is vibrated, first remove the connecting bolts of the wedge-shaped formwork on one side, then knock it loose with a hammer, and then use a crowbar to remove the wedge-shaped formwork on that side. After the upper column formwork on that side is opened, remove the wedge-shaped formwork on the other side in the same way; Step 7.2: Removal of the upper column formwork: First, hang the hooks on both pieces of formwork, then remove all bolts from top to bottom, install the formwork removal bracket and jack, push open one side of the column formwork, then add steel hoops to the column, and use the jack to push open and lift away the other piece of column formwork.

[0009] Furthermore, in step 4, the height of the mortar leveling layer is 50 mm, and it is ensured that the mortar does not enter the column cross section.

[0010] The present invention has the following beneficial effects: The present invention avoids the problems of distortion and tilt of the column reinforcement cage due to its heavy dead weight, which makes formwork reinforcement more difficult and the quality of concrete casting is poor, and eliminates the need for an ultra-high operating scaffolding body required for reinforcement of the reinforcement and formwork, thus saving materials for installation and disassembly of the disc-shaped scaffolding and avoiding the potential safety hazards of the ultra-high frame body. The molding quality of the concrete structure is also guaranteed by the construction method of inserting the steel column formwork. The technology is highly operational, mature and reliable, and has more obvious advantages, especially in the construction of second-floor frame columns of multi-story factories with higher floor heights. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is the construction flow chart of the steel formwork insertion of the second-floor frame columns of a multi-story factory building; Figure 2 This is a schematic diagram of the hoisting of the second-floor frame column; Figure 3 This is the cross-sectional view of the steel formwork joint of the second-floor frame column; Figure 4 It is the node plan of the automobile crane hoisting station; Figure 5 It is the cross-sectional view of the supporting node of the truck crane; In the figure: 1. Truck crane; 2. Second-floor frame column; 4. Guy rope; 6. Mortar leveling layer; 7. First-floor column reinforcement dowel bar; 8. Steel column formwork; 10. Second-floor column lap reinforcement; 11. Steel plate; 12. Square steel pipe; 13. Second-floor frame beam; 14. Second-floor beam; 15. Second-floor main frame beam. DETAILED DESCRIPTION

[0012] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0013] The method for inserting steel formwork for the second-floor frame column of a multi-story factory building according to the present invention is as follows: Figure 1 As shown, the specific process includes the following: Step 1: Construction preparation; Step 1.1: Establish a research group for the second-floor frame column construction plan of multi-story factories and clarify the organizational structure and personnel division of labor.

[0014] Step 1.2: Check the construction drawings and construction atlas "22G101-1". According to the general nodes in the drawings, the frame column reinforcement can be connected by lap joints, but when the column reinforcement is large, mechanical sleeve connection is required; by checking page 2-4 of "22G101-1", it is shown that "when the diameter of the tensile steel bar is greater than 25mm and the diameter of the compressive steel bar is greater than 28mm, binding lap joints should not be used"; it can be concluded that the second-floor frame column 2 with a column reinforcement diameter ≤25mm can be connected by lap joints.

[0015] Step 1.3: Based on the conclusion of step 1.2, select the second-floor frame columns 2 that can be overlapped with column reinforcement and conduct data statistics; rent the corresponding matching steel column formwork 8 according to the height of the selected second-floor frame columns 2, and determine the construction method of steel formwork insertion for the installation of frame column column reinforcement.

[0016] Step 1.4: Determine to use the mobile crane 1 to lift the steel cage and steel column formwork 8 of the second-floor frame column 2. The lifting plan of the mobile crane 1 needs to be calculated by the design institute for the floor load and the plan can be implemented only after it is verified by experts.

[0017] Step 1.5: Provide technical briefing and pre-job technical training to all workers.

[0018] Step 2: Binding of steel cage for second floor frame column 2; Use a mobile binding frame to bind the steel bars at the side of the column, and lift it directly after binding. Among them, a 200*200*12mm wooden board needs to be padded at the lower end of the binding frame column to prevent the steel cage from deformation caused by column settlement. The protective layer is positioned by criss-cross steel bar welding, which can be 5mm smaller than the actual column formwork size. The welding must be firm. A criss-cross positioning rib (circular pads can also be used) is set every two meters. The length of the lifting point steel bar extending out of the steel cage is 100mm. Threaded steel bars also need to be welded in the other direction, but they do not need to extend out of the steel cage. A 200mm concrete pouring port is reserved in the middle PVC casing of the steel cage, and at least two diagonal holes for vibration rods are reserved.

[0019] Step 3: Assembling the steel column mold 8; Step 3.1: Place the steel column form 8; place a U-shaped steel column form 8 flat on the ground, pad the steel column form 8 with square wood to ensure that it is as horizontal as possible, with a cantilever length of ≤1.5m. It is strictly forbidden to place the square wood in the middle of the span of the vertical square tube of the steel column form 8 to avoid deformation of the square tube. Adjust the inclination of the square wood to reduce the distortion of the steel column form 8 as much as possible.

[0020] Step 3.2: Apply mold release agent to the steel column mold 8; before each use of the steel column mold 8, clean the cement and rust on the surface, and apply oily mold release agent after cleaning. It is strictly forbidden to apply the agent at the joints. Stick the foam strips firmly at the joints and special-shaped transitions to prevent the foam strips from falling off during the subsequent mold closing process.

[0021] Step 3.3: Place the steel cage; use the automobile crane 1 to lift the steel cage tied in step 2 into the steel column mold 8, and check the direction and embedded parts to ensure the correct position. At the same time, check whether the limiting steel bars at the column cap are firmly welded.

[0022] Step 3.4: Close the steel column mold 8; before closing the mold, check whether the template is deformed, especially the flatness of the joints to prevent leakage; then put a U-shaped template upside down on the lower U-shaped mold, use a crowbar to align it with the bolt holes of the column mold, and then slowly put it in place, first insert the first bolt at both ends and tighten it initially, then adjust the horizontality of the lower U-shaped mold and insert all bolts at the same time, and the final tightening should be carried out symmetrically from both sides of one end at the same time, and the torque should reach more than 280N·m.

[0023] Step 4: Level the column bottom; The column center line, column section edge line and control line are popped up. Before installing the steel column form 8, the elevation and coordinates are checked to determine the position of the steel column form 8, and a marker is used to mark it for easy installation. The bottom of the steel column form 8 is leveled with mortar, and the height of the mortar leveling layer 6 is 50mm. The mortar of the leveling layer is strictly prohibited from entering the column section.

[0024] Step 5: Figure 2 , 3 As shown, the steel column mold 8 is hoisted and inserted; Step 5.1: The main hook and the auxiliary hook rise simultaneously to lift the steel column mold 8 to a certain height from the ground, and the main hook is lifted to lift the steel column mold 8 to a vertical state. In order to avoid collision between the steel wire and the tool-type guardrail, etc., the main hook is hung with a cross bar connected to the upper end of the steel column mold 8.

[0025] Step 5.2: The overlap percentage of the steel cage in the steel column form 8 (first-floor column reinforcement inserted reinforcement 7) and the reserved reinforcement of the second-floor floor 5 frame column (second-floor column lap column reinforcement 10) is 50%, and the overlap length is 1.4LaE; the stirrups in the overlap section should use welded closed stirrups, and the overlap is divided into inner stirrups for encryption.

[0026] Step 5.3: If Figure 2 As shown, when the crane loosens the wire rope but does not unhook it, the wire ropes 4 on the four sides of the steel column formwork 8 are tied to the pre-buried lifting rings on the floor through a 3t tensioner or a 3t hoist. Use a theodolite or a plumb bob hung on the steel column formwork 8 to check the verticality and command the tensioners in each direction to adjust. After confirming the verticality, tighten the tensioner.

[0027] Step 6: pouring concrete for frame columns; Control the concrete slump to 180mm. Ensure that there is no segregation after concrete pouring. At the same time, inject 200-300mm thick high-sand ratio concrete with two grades increased before pouring concrete, and then pour concrete.

[0028] Step 7: Dismantle the steel column form 8; Step 7.1: Removal of the wedge-shaped formwork at the base: 24 hours after the concrete is vibrated (extended to 36 hours below 10°C), the guy rope 4 can be loosened. First, remove the connecting bolts of the wedge-shaped formwork on one side, then knock it loose with a hammer, and then use a crowbar to remove the wedge-shaped formwork on that side. After the upper column formwork on that side is pushed open, remove the wedge-shaped formwork on the other side in the same way.

[0029] Step 7.2: Removal of the upper column formwork: First, hang the hooks on both pieces of formwork, then remove all bolts from top to bottom, install the formwork removal bracket and jack, push open one side of the column formwork, then add steel hoops to the column, and use the jack to push open and lift away the other piece of column formwork.

[0030] Step 8: Concrete frame column coating and maintenance; After the concrete column formwork is removed, use a water gun to water or spray concrete curing agent immediately, and wrap the column body with a film.

[0031] In the above process, when the mobile crane 1 is hoisting, the layout of the mobile crane 1 and the supporting nodes are as follows: Figure 4 , 5 As shown, the bottom is supported by a 400×500×50mm thick steel plate 11, a 3500-length 400×300×12mm thick square steel tube 12, a second-layer frame beam 13, a second-layer beam 14, and a second-layer main frame beam 15.

[0032] The embodiments are preferred implementations of the present invention, but the present invention is not limited to the above-mentioned implementations. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essential content of the present invention belong to the protection scope of the present invention.

Claims

1. A method for inserting steel formwork for second-floor frame columns of a multi-story factory building, characterized in that: The process includes the following: Step 1: Consult the data to determine the second-floor frame columns that can be overlapped with column reinforcement (2), and determine the lifting machinery and lifting plan; Step 2: Binding of steel cages for second-floor frame columns (2); Step 3: Assembling the steel column mold (8); Step 4: The bottom of the steel column mold (8) is leveled with mortar to form a mortar leveling layer (6); Step 5: The steel column mold (8) is hoisted and inserted; Step 6: Concrete pouring of second-floor frame columns (2); Step 7: Removal of steel column formwork (8) Step 8: Cover and maintain the second-floor frame columns (2).

2. The method for inserting steel formwork for the second-floor frame columns of a multi-story factory building according to claim 1 is characterized in that: In step 2, a mobile binding frame is used to bind the steel cage, and the cage is directly lifted after binding. A wooden board is placed at the lower end of the binding frame column to prevent the column from sinking and causing deformation of the steel cage. The protective layer is welded and positioned with a tic-tac-toe positioning bar. A tic-tac-toe positioning bar is arranged every two meters. The steel bars at the lifting point extend out of the steel cage, and threaded steel is also welded in the other direction, but it does not need to extend out of the steel cage. A concrete pouring port is reserved in the middle PVC casing of the steel cage, and at least two diagonal holes for the vibration rod are reserved.

3. The method for inserting steel formwork for the second-floor frame columns of a multi-story factory building according to claim 1 is characterized in that: The specific process of step 3 is as follows: Step 3.1: Place a U-shaped steel column mold (8) flat on the ground, place square wood under the steel column mold (8), and adjust the inclination of the square wood to reduce the distortion of the steel column mold (8); Step 3.2: Before each use of the steel column mold (8), clean the cement and rust on the surface, and apply oil-based mold release agent after cleaning, except for the joints. Foam strips are pasted at the joints and special-shaped transitions; Step 3.3: Using a truck crane (1), lift the bound steel cage into the steel column mold (8); Step 3.4: Close the steel column mold (8); first check whether the mold is deformed and check the flatness of the joints to prevent leakage; then put a U-shaped mold upside down on the lower U-shaped mold, use a crowbar to align the bolt holes of the column mold, slowly put it in place, first insert the first bolt at both ends and tighten it, then adjust the horizontality of the lower U-shaped mold and insert all bolts at the same time, and when tightening, do it symmetrically from both sides of one end at the same time.

4. The method for inserting steel formwork for the second-floor frame columns of a multi-story factory building according to claim 1 is characterized in that: The specific process of step 5 is as follows: Step 5.1: The main hook and the auxiliary hook are raised simultaneously to lift the steel column mold (8) off the ground, and the main hook is lifted to lift the steel column mold (8) to a vertical state. In order to prevent the steel wire from colliding with the tool-type guardrail, the main hook is hung with a cross bar connected to the upper end of the steel column mold (8); Step 5.2: The overlap percentage of the steel cage inside the steel column form (8) and the reserved steel bars of the frame column of the second floor (5) is 50%, and the overlap length is 1.4LaE; the stirrups in the overlap section are welded closed stirrups, and the overlap part is the inner stirrup reinforcement; Step 5.3: When the crane is in the state of loosening the steel wire rope but not unhooking it, tie the steel wire ropes (4) on the four sides of the steel column formwork (8) to the pre-buried lifting rings on the floor through a tensioner or hoist, use a theodolite or a plumb bob hung on the steel column formwork (8) to check the verticality and adjust the tensioners in each direction. After confirming the verticality, tighten the tensioners.

5. The method for inserting steel formwork for the second-floor frame columns of a multi-story factory building according to claim 1 is characterized in that: The specific process of step 7 is as follows: Step 7.1: Removal of the wedge-shaped formwork at the base: Loosen the cable wind rope (4) 24 hours after the concrete is vibrated, first remove the connecting bolts of the wedge-shaped formwork on one side, and then knock it loose with a hammer, and then use a crowbar to remove the wedge-shaped formwork on that side. After the upper column formwork on that side is opened, remove the wedge-shaped formwork on the other side in the same way; Step 7.2: Removal of the upper column formwork: First, hang the hooks on both pieces of formwork, then remove all bolts from top to bottom, install the formwork removal bracket and jack, push open one side of the column formwork, then add steel hoops to the column, and use the jack to push open and lift away the other piece of column formwork.

6. The method for inserting steel formwork for the second-floor frame columns of a multi-story factory building according to claim 1 is characterized in that: In step 4, the height of the mortar leveling layer (6) is 50 mm, and it is ensured that the mortar does not enter the column cross section.

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