A self-supporting box formwork system and construction method for large-span hollow floor construction

Abstract

A self-supporting box formwork system for large-span hollow floor construction, comprising: a plurality of columns, the top of the column being fixedly provided with a support frame; a plurality of spliced bottom forms, the spliced bottom forms being laid and installed on the support frame, the plurality of spliced bottom forms being mutually spliced through a clamping structure and forming a continuous pouring bottom surface; and a plurality of self-supporting box forms, the self-supporting box forms being detachably installed on the spliced bottom forms, and the adjacent self-supporting box forms being reserved with intervals and forming rib beam channels. The support frame is used to replace the traditional full-dense support, the number of vertical rods and connecting pieces is greatly reduced, the lower operation space is released, the passing, transportation and multi-work cross construction are facilitated, and the construction organization is more efficient. The continuous support, higher stiffness and more accurate forming are realized: the support frame cooperates with the cross beam to uniformly support the spliced bottom form, the overall stiffness is significantly improved, the settlement, sagging and joint misalignment are effectively reduced, the bottom surface flatness and elevation control are more stable, and the floor forming quality is higher.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a self-supporting box formwork system and construction method for large-span hollow floor slab construction. Background Technology

[0002] Cast-in-place reinforced concrete hollow slab floor systems are widely used in large-space structures such as underground parking garages, commercial complexes, exhibition buildings, transportation hubs, and industrial plants due to their advantages such as light weight, large span, flat bottom surface, good bidirectional load-bearing capacity, and strong adaptability to mechanical and electrical pipeline layout. In engineering projects, self-supporting boxes or hollow boxes are often used as inner molds, forming a bidirectional ribbed hollow slab floor system by integral casting with cast-in-place concrete.

[0003] Currently, the construction of large-span hollow core slabs generally adopts a traditional formwork support system consisting of full-span scaffolding / dense uprights support + timber / steel beam support + integral bottom formwork laying + self-supporting box installation. To prevent the self-supporting boxes from floating or drifting, additional temporary measures such as pressure bars, binding, local restraint, and additional counterweights are required on site. This traditional construction method has the following drawbacks: The dense supporting components and narrow working space below hinder material transportation, personnel passage and the interweaving of different trades, making construction organization difficult. The load-bearing path is dispersed and the overall stiffness is insufficient. Under the conditions of large span and thick plate, it is easy to have accumulated support settlement, bottom formwork deflection, misalignment of joints and inconsistent elevation, which affects the accuracy of floor forming. The self-supporting box relies on temporary measures for buoyancy resistance and positioning, which are constrained, have poor stability, and are prone to box drift, array offset, and local misalignment, resulting in rib beam section deviation and concrete defects. The system has complicated assembly and disassembly procedures, many types of components, high dependence on manual labor, low turnover efficiency, large material loss, and high overall construction cost. It has poor adaptability to large-span, high-clearance scenarios, makes it difficult to balance structural load-bearing capacity and construction space requirements, and has a low degree of standardization and modularization.

[0004] Based on this, developing a hollow floor slab formwork system with fewer support points, stable load-bearing capacity, accurate elevation, reliable box positioning, and efficient modular turnover has become a technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to solve the problems pointed out in the background art and to propose a self-supporting box formwork system for the construction of large-span hollow floor slabs.

[0006] The objective of this invention can be achieved through the following technical solutions: A self-supporting box formwork system for the construction of large-span hollow floor slabs includes: Multiple columns, with a support frame fixedly installed on the top of each column; Multiple splicing bottom molds are laid on the support frame. The bottom of the splicing bottom molds is provided with threaded holes, and bolts that correspond to the threaded holes can be inserted on the support frame. The bolts are tightened into the threaded holes for fixation. Multiple splicing bottom molds are spliced ​​together by a snap-fit ​​structure to form a continuous casting bottom surface. Multiple self-supporting box templates are provided, which can be detachably installed on the splicing bottom formwork. Spacing is reserved between adjacent self-supporting box templates to form rib beam channels.

[0007] Simplified support and open space: The column + support frame structure with fewer support points replaces the traditional dense scaffolding, which greatly reduces the number of uprights and connectors, frees up the working space below, facilitates passage, transportation and cross-construction of multiple trades, and makes the construction organization more efficient.

[0008] Continuous support, higher rigidity, and more precise molding: The support frame, together with the crossbeams, provides uniform support for the splicing bottom formwork, significantly improving overall rigidity, effectively reducing settlement, deflection, and misalignment at the joints, resulting in more stable bottom surface flatness and elevation control, and higher quality floor slab molding.

[0009] As a further aspect of the present invention: at least two sides of the splicing bottom mold are provided with dovetail grooves along their length direction, and multiple splicing bottom molds are positioned by interlocking with each other through the dovetail grooves and locked and fixed by connectors.

[0010] Reliable splicing and leak-proof sealing: The splicing bottom formwork adopts dovetail groove interlocking and connector fixing, and the splice joint is equipped with a sealing structure. The positioning is accurate and the connection is firm, which avoids grout leakage and misalignment from the structure and improves the forming effect of the concrete bottom surface.

[0011] As a further aspect of the present invention: the splicing bottom mold is provided with an installation component, and the self-supporting box template is provided with a corresponding locking component. The locking component and the installation component cooperate with each other to limit the position and prevent the self-supporting box template from falling off.

[0012] The mounting component can be a snap-fit, and the locking component can be a latch. The snap-fit ​​and the latch work together to secure the device.

[0013] As a further aspect of the present invention: the self-supporting box template includes a bottom mold and a side mold, the side mold is fixed on the bottom mold and forms an integral structure, and a sealing strip is provided on the top of the side mold, the sealing strip is tightly fitted and sealed with the upper surface of the spliced ​​bottom mold.

[0014] As a further aspect of the present invention: the bottom mold is provided with a first reinforcing rib and the side mold is provided with a second reinforcing rib, which is used to improve the overall rigidity of the self-supporting box template.

[0015] As a further aspect of the present invention: the side of the support frame protrudes outward and is provided with a top plate connector, and a crossbeam can be detachably installed between the top plate connectors of adjacent support frames. The crossbeam is used to support the splicing bottom formwork.

[0016] As a further aspect of the present invention, a cross brace and a crossbar can be detachably installed between two adjacent columns to improve the overall stability and lateral displacement resistance of the support system.

[0017] A construction method comprising the following steps: S1. Measurement and layout of support points: Determine the installation positions of columns, support frames and splicing bottom formwork according to the floor design parameters. S2. Foundation treatment and column installation: Level the supporting surface, install the columns and ensure verticality; S3. Install connecting components, including horizontal bars and cross braces between the columns, to form a stable support system; S4. Install the support frame and crossbeams, fix the support frame to the top of the column, and install the crossbeams between the top plate connectors; S5. Lay out the splicing bottom mold, and fix the splicing bottom mold by dovetail groove and connector to form a continuous bottom surface; S6. Install the self-supporting box template. Arrange the self-supporting box template in an array on the splicing bottom mold and fix it by locking parts. S7. Reinforcement binding and concrete pouring: Bind the rib beams and surface reinforcement, and pour concrete in sections and layers. S8. Curing, demolding and reuse: After the concrete reaches its strength, the self-supporting box formwork, splicing bottom formwork, support frame and columns are removed in sequence. The components are cleaned and reused. Attached Figure Description

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a structural schematic diagram of the self-supporting box template; Figure 3 This is a schematic diagram showing the support position between the supporting frame and the splicing bottom formwork; Figure 4 yes Figure 3 Enlarged view of point A in the middle; Figure 5 This is a schematic diagram showing the connection between the column and the connecting components.

[0020] In the diagram: 1. Column; 106. Support frame; 2. Connecting component; 201. Horizontal bar; 202. Cross brace; 203. Top plate connector; 204. Connecting component; 3. Splicing bottom formwork; 301. Dovetail groove; 302. Connector; 303. Fixture; 4. Self-supporting box formwork; 401. Bottom formwork; 402. Side formwork; 403. First reinforcing rib; 404. Second reinforcing rib; 405. Sealing strip; 5. Rib beam channel. Detailed Implementation

[0021] 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 some embodiments of the present invention, and not all embodiments. 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.

[0022] The columns 1 are arranged at the designed spacing, with their bottoms supported on the leveled floor or foundation surface, and the tops fixedly installed with the support frame 106. Horizontal bars 201 and cross braces 202 are installed between adjacent columns 1 via connecting components 204 to form a stable lower structure, effectively resisting horizontal lateral displacement and overturning, and improving the overall support safety.

[0023] The side of the support frame 106 protrudes outward to provide the top plate connector 203. A crossbeam can be detachably installed between the top plate connectors 203 of adjacent support frames 106. The crossbeam provides uniform support to the spliced ​​bottom mold 3, making the stress more stable and the overall rigidity higher.

[0024] The support frame 106 can be tightened and locked to the splicing bottom mold 3 by means of bolts or other methods.

[0025] The splicing bottom formwork 3 is a modular panel, with dovetail grooves 301 on at least two sides along its length. Multiple splicing bottom formwork 3 panels are interlocked and positioned by the dovetail grooves 301 and further secured by connectors 302. A sealing structure is provided in the joint to prevent grout leakage during concrete pouring. Mounting components are provided on the splicing bottom formwork 3 for use with the self-supporting box formwork 4 for positioning.

[0026] The self-supporting box formwork 4 includes a bottom mold 401 and side molds 402, with the side molds 402 fixed to the bottom mold 401 to form an integral structure. A first reinforcing rib 403 is provided on the bottom mold 401, and a second reinforcing rib 404 is provided on the side mold 402 to improve the structural rigidity of the self-supporting box formwork 4 and prevent deformation during pouring and vibration. A sealing strip 405 is provided on the side of the side mold 402 away from the bottom mold 401, and the sealing strip 405 fits tightly against the upper surface of the spliced ​​bottom mold 3 to achieve a leak-proof seal. Locking components that match the installation parts of the spliced ​​bottom mold 3 are provided on the self-supporting box formwork 4; the two lock together to reliably limit the position of the self-supporting box formwork 4 and prevent floating and displacement during pouring.

[0027] Multiple self-supporting box formwork 4 are arranged in an array on the splicing bottom formwork 3 according to the design. The interval between adjacent self-supporting box formwork 4 forms a rib beam channel 5, which is used to pour rib beam concrete and together with the surface concrete, forms a two-way dense rib hollow floor slab structure.

[0028] This invention also provides a supporting construction method, the steps of which are as follows: S1. Measurement and layout of support points: Determine the installation positions of column 1, support frame 106 and splicing bottom formwork 3 according to the floor span, slab thickness and box module. S2. Foundation treatment and column 1 installation: Clean and level the supporting surface, install column 1 and correct its verticality. S3. Install connecting components, install horizontal bars 201 and cross braces 202 between columns 1 to form an overall stable support system; S4. Install the support frame 106 and the crossbeam, fix the support frame 106 to the top of the column 1, and install the crossbeam between the top plate connectors 203. S5. Lay the splicing bottom mold 3, and fix the splicing bottom mold 3 by dovetail groove 301 and connector 302 to form a continuous flat bottom surface. The splicing seam is sealed. S6. Install the self-supporting box template 4. Arrange the self-supporting box template 4 in an array on the splicing bottom mold 3, and fix it by locking and installing parts. S7. Reinforcement binding and concrete pouring: Bind the rib beams and surface reinforcement, and pour concrete in sections and layers, with the rib beams first and the surface layer second. S8. Curing, demolding and reuse: After the concrete reaches the design strength, it is removed in the following order: self-supporting box formwork 4, splicing bottom formwork 3, support frame 106, and column 1. After cleaning and inspection, the components are reused.

[0029] In another construction plan: S1. Measurement and layout of support points: Determine the installation positions of column 1, support frame 106 and splicing bottom formwork 3 according to the floor span, slab thickness and box module; column 1 is arranged in a grid with a spacing of 2.0m to 2.5m, with a plane positioning deviation ≤ ±3mm and an elevation control deviation ≤ ±5mm.

[0030] S2. Foundation treatment and column 1 installation: Clean and level the supporting surface to ensure that the flatness of the supporting surface is ≤2mm / 2m and the compressive strength is ≥C20; install column 1 and correct the verticality, with a verticality deviation of ≤1 / 1000; set a 500mm×500mm×20mm steel pad at the bottom of column 1 to prevent local settlement.

[0031] S3. Install connecting components: Install horizontal bars 201 between columns 1 at a height of 300mm to 500mm from the ground, and install cross braces 202 at half the height of the columns; the horizontal bars 201 and cross braces 202 are made of Φ48mm×3.5mm steel pipes and are fastened through connecting components 204, with the bolt tightening torque ≥40N. m, forming an overall stable support system.

[0032] S4. Install the support frame 106 and the crossbeam: Fix the support frame 106 to the top of the column 1. The horizontal deviation of the support frame 106 is ≤2mm / total length. Install a 100mm×50mm rectangular steel pipe crossbeam between the top plate connectors 203. Connect them with M12 bolts to form a continuous support surface. The elevation deviation is ≤±3mm.

[0033] S5. Laying the splicing bottom mold 3: The splicing bottom mold 3 is engaged by the dovetail groove 301 and fixed by the connector 302. The splicing bottom mold 3 adopts a standard module of 600mm×1200mm. A 3mm thick EPDM sealing strip is set in the splice joint, the splice joint width is ≤1mm, and the overall flatness is ≤2mm / 2m.

[0034] S6. Install the self-supporting box template 4: Arrange the self-supporting box template 4 on the splicing bottom mold 3 in a 600mm modular array, and fix it by locking and installing parts; the sealing strip 405 is pressed against the splicing bottom mold 3 by ≥2mm, and the width deviation of the rib beam channel 5 is ≤±2mm.

[0035] S7. Reinforcement binding and concrete pouring: Bind the rib beams and surface reinforcement, with a reinforcement protective layer thickness deviation of ≤±3mm; use C30~C40 concrete, pour in sections and layers, with each layer thickness ≤300mm, first pour the rib beams and vibrate them to compact them, then pour the surface concrete; the vibrator should be ≥50mm away from the edge of the self-supporting box formwork.

[0036] S8. Curing, demolding and reuse: Cover and moisturize the concrete within 12 hours after pouring, and cure for ≥14 days; demolding can only be carried out after reaching 100% of the design strength; demold in the following order: self-supporting box formwork 4 → splicing bottom formwork 3 → support frame 106 → crossbeam → connecting component 2 → column 1; reuse the components after cleaning and inspection, with a reuse count of ≥50 times.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A self-supporting box formwork system for the construction of large-span hollow floor slabs, characterized in that, include: Multiple columns (1) with a supporting frame (106) on top; Multiple splicing bottom molds (3) are provided on the support frame (106) and the multiple splicing bottom molds (3) are interlocked and spliced ​​together; Multiple self-supporting box templates (4) are detachably installed on the splicing bottom mold (3), and the intervals between the multiple self-supporting box templates (4) form rib beam channels (5).

2. The self-supporting box formwork system according to claim 1, characterized in that, At least two edges of the splicing bottom mold (3) are formed with dovetail grooves (301) along their length direction, and multiple splicing bottom molds (3) are engaged with each other through the dovetail grooves (301).

3. The self-supporting box formwork system according to claim 1, characterized in that, The multiple splicing bottom molds (3) are also fixed to each other by connectors (302).

4. The self-supporting box formwork system according to claim 1, characterized in that, The splicing bottom mold (3) is provided with an installation component, and the self-supporting box template (4) is provided with a locking component corresponding to the installation component. The locking component and the installation component are locked together for limiting the position.

5. The self-supporting box formwork system according to claim 1, characterized in that, The self-supporting box template (4) includes a bottom mold (401) and a side mold (402). The side mold (402) is fixed on the bottom mold (401) and the two are integrated. A sealing strip (405) is provided on the side of the side mold (402) away from the bottom mold (401). The sealing strip (405) is in contact with the splicing bottom mold (3).

6. The self-supporting box formwork system according to claim 5, characterized in that, The bottom mold (401) is also provided with a first reinforcing rib (403), and the side mold (402) is provided with a second reinforcing rib (404).

7. The self-supporting box formwork system according to claim 1, characterized in that, The side of the support frame (106) protrudes outward to form at least one top plate connector (203), and a crossbeam is detachably installed between the top plate connectors (203) on the two support frames (106), the crossbeam being used to support the splicing bottom mold (3).

8. The self-supporting box formwork system according to claim 1, characterized in that, A cross brace (202) and a crossbar (201) are detachably installed between the two columns (1).

9. A construction method applicable to the self-supporting box formwork system as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Measure and lay out the support points, and determine the installation positions of the columns (1), support frame (106) and splicing bottom formwork (3) according to the floor design parameters; S2. Foundation treatment and column (1) installation: Level the supporting surface, install the column (1) and ensure verticality; S3. Install connecting components, install horizontal bars (201) and cross braces (202) between columns (1) to form a stable support system; S4. Install the support frame (106) and the crossbeam, fix the support frame (106) to the top of the column (1), and install the crossbeam between the top plate connectors (302); S5. Lay the splicing bottom mold (3), and fix the splicing bottom mold (3) by using the dovetail groove (301) and the connector (302) to form a continuous bottom surface; S6. Install the self-supporting box template (4). Arrange the self-supporting box template (4) in an array on the splicing bottom mold (3) and fix it by locking parts. S7. Reinforcement binding and concrete pouring: Bind the rib beams and surface reinforcement, and pour concrete in sections and layers. S8. Curing, demolding and reuse: After the concrete reaches its strength, the self-supporting box formwork (4), splicing bottom formwork (3), support frame (106) and column (1) are removed in sequence. The components are cleaned and reused.

10. The construction method according to claim 9, characterized in that, In step S5, when the splicing bottom mold (3) is laid, it is positioned and engaged by the dovetail groove (301), and a sealing structure is set at the splice joint to prevent grout leakage during concrete pouring.

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