A construction method of a composite floor band reinforcement leakproof slurry and application thereof

Abstract

This invention provides a method for reinforcing and preventing grout leakage in composite floor slabs and its application, belonging to the field of building construction technology. The invention includes the following steps: pre-drilling holes in a polytetrafluoroethylene (PTFE) formwork according to fixed points; arranging secondary ribs, bottom channel steel, and main ribs; placing upper embedded cross-connectors, one end of which crosses over two adjacent composite floor slabs, and the other end sequentially passing through a downward-facing PVC conical nut, the pre-drilled hole on the upper surface of the PTFE formwork, and the bottom channel steel, thus reinforcing the slab strip. This invention uses PTFE formwork as the bottom formwork for slab strip leak prevention, combined with a fixed formwork system consisting of upper embedded cross-connectors, PVC conical nuts, and bottom channel steel, eliminating the need for full-span support scaffolding. It can precisely seal the joint gap between the composite slab and the slab strip formwork, preventing grout leakage and slab misalignment at the source, while also reducing on-site construction workload. The core reinforcement components are reusable, significantly improving construction efficiency and reducing overall costs.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a construction method for reinforcing and preventing grout leakage of composite floor slabs and its application, which is especially suitable for the construction of large-span arched composite floor slabs. Background Technology

[0002] Composite slab strips are structural measures used in prefabricated composite slab construction to ensure structural integrity and improve structural performance. Conventional large-span cambered composite slab strips are supported by steel pipes, with sponge strips attached to the edges of the formwork as a grout leakage prevention measure. Large-span floor slabs need to be cambered according to design requirements, and the cast-in-place beams should camber synchronously. However, as precast components, composite slabs cannot camber in sync with the cast-in-place beams. During the formwork erection at the strip area, gaps easily appear between the formwork and the composite slab, leading to loose strip joints, misalignment of the slab bottom, and poor surface appearance of the concrete after demolding. This is the main quality challenge currently faced by this construction process. Summary of the Invention

[0003] In view of this, to address the technical problems of grout leakage at splice joints and misalignment at the bottom of slabs in traditional construction of precast composite floor slabs in large-span arched scenarios, which are prone to such issues, as well as the need for full-span scaffolding, resulting in low construction efficiency and high costs, this invention provides a method for reinforcing and preventing grout leakage in composite floor slab strips and its application. Using polytetrafluoroethylene (PTFE) formwork as the bottom formwork for the slab strip, and employing a dedicated reinforcement component system consisting of upper embedded cross-connectors, PVC tapered nuts, and bottom channel steel, the formwork system is fixed, eliminating the need for full-span support scaffolding. This solution can precisely seal the splice gaps between the composite slab and the formwork strip, fundamentally preventing grout leakage and misalignment at the bottom of the slab, while also reducing on-site construction workload. The core reinforcement components are reusable, significantly improving construction efficiency and reducing overall costs.

[0004] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a construction method for reinforcing and preventing grout leakage of composite floor slabs with strip reinforcement, comprising the following steps: Step (1): Use a polytetrafluoroethylene template as a plate and strip support template, and pre-drill holes in the polytetrafluoroethylene template according to the fixed points; Step (2): Arrange secondary ribs below the polytetrafluoroethylene template, arrange the bottom channel steel of the fixing device in a direction perpendicular to the secondary ribs, and arrange the main ribs below the bottom channel steel in a direction perpendicular to the bottom channel steel. Step (3): Place the upper pre-embedded cross-connector. One end of the upper pre-embedded cross-connector is connected to two adjacent composite floor slabs, and the other end passes through the PVC tapered nut with the opening facing down, the pre-drilled hole on the upper surface of the polytetrafluoroethylene template, and the bottom channel steel in sequence. Then, lock and fix the upper pre-embedded cross-connector, polytetrafluoroethylene template, secondary rib and main rib to complete the plate and strip reinforcement.

[0005] Secondly, the present invention provides the application of the above-mentioned composite floor slab strip reinforcement and anti-leakage construction method in the construction of large-span arched composite floor slab strips.

[0006] Compared with the prior art, the present invention has the following beneficial effects: More stable and reliable molding quality: Using polytetrafluoroethylene templates as the bottom mold of the slab strip, combined with the pre-embedded locking fixing method, the splicing gap between the composite slab and the slab strip template can be completely sealed. After demolding, there is no grout leakage or protrusion at the joint between the slab strip and the composite floor slab, and no misalignment of the bottom of the slab. No additional surface repair work is required. The molding quality is highly consistent and is not affected by the operating experience of on-site personnel.

[0007] The construction process is simpler and more efficient: there is no need to erect full-span support scaffolding, and all reinforcement work can be completed through a mobile operating platform. The process is simple and easy to learn, which greatly shortens the preparation and operation cycle of the slab and strip construction and makes it more adaptable to the construction progress requirements of large-span structures.

[0008] Lower overall construction costs: Core components such as PTFE formwork, upper embedded cross-connectors, PVC tapered nuts, bottom channel steel, secondary ribs, and main ribs can all be reused, and there is no need to purchase additional release agents or misalignment repair materials, resulting in a significant reduction in overall investment compared to traditional strip construction methods.

[0009] It has stronger adaptability to various scenarios: It can be adapted to various complex slab construction scenarios such as large-span composite floor slabs with camber height differences, and splicing of cast-in-place beams and precast composite slabs. No additional formwork adjustment procedures are required for camber height differences, making it more universally applicable.

[0010] During the construction of the composite slab in the Xiongdong Comprehensive Cultural and Sports Center project, the method provided by this invention can effectively improve the construction quality of the cast-in-place slab strip, solve the quality pain points on the construction site, meet the functional requirements of the building, ensure the structural safety, not only greatly improve construction efficiency, but also significantly save costs. Attached Figure Description

[0011] Figure 1 This is a front view of the fixing device of the present invention; Figure 2 This is a left view of the fixing device of the present invention; Figure 3 This is a top view of the fixing device of the present invention; Figure 4 This is an overall rendering of the invention; In the diagram, 1. PTFE template; 2. Secondary rib; 3. Main rib; 4. Upper embedded cross-connector; 5. Bottom channel steel; 6. Connector; 7. PVC tapered nut; 8. Supporting steel bar; 9. Threaded rod. Detailed Implementation

[0012] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0013] like Figure 1-4 As shown, this invention provides a construction method for reinforcing and preventing grout leakage in composite floor slabs. This method uses polytetrafluoroethylene (PTFE) formwork 1 instead of ordinary formwork to ensure a tight bond between the formwork and the composite floor slab, preventing grout leakage. Reinforcement is achieved using a fixing device, reducing scaffolding requirements, improving construction efficiency, and saving costs. The construction method includes the following steps: Step (1): Use PTFE template 1 as the support template and pre-drill holes in PTFE template 1 according to the fixed points. In this step (1), PTFE template 1, which does not adhere to concrete and has a high surface flatness, is selected as the bottom template of the strip. Holes are pre-drilled according to the fixed points to avoid temporary drilling on site damaging the template structure and causing positioning deviation. This avoids the problem of concrete sticking to the template when demolding from the material source. The pre-drilled holes ensure accurate positioning of the subsequent locking parts and prevent template displacement and splicing gaps due to hole deviation.

[0014] Step (2): Secondary ribs 2 are installed below the PTFE template 1, and bottom channel steel 5 of the fixing device is installed along the direction perpendicular to the secondary ribs 2. Main ribs 3 are installed below the bottom channel steel 5 along the direction perpendicular to the bottom channel steel 5. The secondary ribs 2 directly support the PTFE template 1, providing uniform local support for the PTFE template 1. The bottom channel steel 5 and main ribs 3 are installed vertically in sequence to form a two-way stress-bearing skeleton, which disperses the local stress generated by subsequent locking to the entire reinforcement system and avoids local stress deformation. The layered stress-bearing structure has sufficient support rigidity, which can ensure the overall flatness of the PTFE template 1 and avoid problems such as unevenness of the bottom of the board and splicing gaps caused by local depressions of the PTFE template 1. All materials used are common consumables on the construction site, which are easy to obtain and can be reused.

[0015] Step (3): Place the upper pre-embedded cross-connector 4. One end of the upper pre-embedded cross-connector 4 is connected to two adjacent composite floor slabs, and the other end passes through the PVC tapered nut 7 with the opening facing downward, the pre-drilled hole on the upper surface of the PTFE template 1, and the bottom channel steel 5 in sequence. Then, lock and fix the upper pre-embedded cross-connector 4, PTFE template 1, secondary rib 2, and main rib 3 to complete the slab reinforcement. Using two adjacent existing composite floor slabs as the upper load-bearing fulcrum, the PTFE template 1, secondary rib 2, and main rib 3 are locked together with the composite slab through the vertical tie structure of the pre-embedded cross-connector. The template support force is provided entirely by the structural bearing capacity of the composite slab, without relying on the lower support system. The process of erecting a full-span scaffold is completely eliminated, reducing the construction space requirements and preparation workload. The force transmission path is direct and stable, and there will be no problems of lower support settlement or displacement. From the structural level, the fit between the template and the composite slab is guaranteed, avoiding grout leakage and misalignment.

[0016] In summary, the above-mentioned technical solution of the present invention completely avoids the problems of settlement and inaccurate positioning of traditional full-span support, has a simple process, low requirements for construction space, and ensures the stability of formwork fixing from a structural level.

[0017] In this invention, in step (2), the spacing between adjacent secondary ribs 2 is 100mm. By densely laying secondary ribs 2, uniform and sufficient support rigidity is provided for the polytetrafluoroethylene template 1, avoiding local stress-induced depression and deformation of the template. This ensures the overall flatness of the bottom mold and prevents splicing gaps and unevenness at the bottom of the template due to template deformation, resulting in higher stability of molding quality.

[0018] In this invention, in step (2), the secondary rib 2 is made of timber, and the main rib 3 is made of double steel pipes. Using timber as the secondary rib 2 is suitable for the material characteristics of polytetrafluoroethylene board, and the buffer fit avoids damage to the template; using double steel pipes as the main rib 3 provides higher overall structural strength, disperses the locking force, and avoids local stress concentration. Both materials are common consumables on construction sites, are easy to obtain, have low cost, and can be reused, with good adaptability.

[0019] In this invention, step (3) includes the upper pre-embedded bridging member 4, which comprises: Supporting steel bar 8 is horizontally connected across two adjacent composite floor slabs; The threaded rod 9 is connected to the support steel bar 8 at one end in the vertical direction of the support steel bar 8, and the other end passes through the PVC tapered nut 7 with the opening facing downward, the pre-drilled hole on the upper surface of the polytetrafluoroethylene template 1, and the bottom channel steel 5 in sequence. Connector 6 is connected to the other end of screw 9. By tightening connector 6, the upper embedded cross-connector 4, polytetrafluoroethylene template 1, secondary rib 2 and main rib 3 are locked and fixed.

[0020] The upper pre-embedded cross-connector 4 uses the supporting steel bars 8 that are horizontally connected to the composite slab as the load-bearing foundation. The locking force is transmitted through the vertically connected threaded rod 9, and finally the bottom connector 6 achieves overall tying and locking from the composite slab to the bottom formwork. The force path is direct and clear. The fixing reliability is high, and the force relies entirely on the existing composite slab structure. There is no need to add an additional lower support structure, which greatly reduces the amount of construction preparation work.

[0021] In this invention, the connector 6 is a U-shaped clip. Using a U-shaped clip as the locking connector 6, its arc-shaped opening can perfectly fit the shape of the double steel pipe main rib 3, ensuring uniform stress distribution during locking and preventing slippage or localized damage to the main rib 3. The U-shaped clip is a standard fastener in the construction field, convenient to operate, low in procurement cost, reusable, and easy to operate, unaffected by worker experience.

[0022] In this invention, the polytetrafluoroethylene (PTFE) template 1 is fitted to the edge of the composite floor slab, and the locking operation eliminates the splicing gap between the composite floor slab and the PTFE template 1. The pressure generated by the locking operation, due to the PTFE template 1's fit against the edge of the composite floor slab, ensures a complete seal between the template and the edge, directly blocking the splicing gap.

[0023] This method avoids grout leakage at the source, eliminating the need for additional sealing materials such as sealant strips and sponge strips, thus reducing construction steps.

[0024] In this invention, no additional release agent is required when removing the PTFE formwork 1, and the concrete surface of the slab strip is smooth and free of misalignment after demolding. Utilizing the inherent non-adhesive properties of PTFE material and the flat support effect of the formwork system, the concrete does not adhere to the formwork during demolding, resulting in a high degree of surface flatness. No additional release agent is needed, saving material costs; the surface of the slab strip is free of misalignment and adhesion marks after demolding, eliminating the need for additional surface repair work and significantly improving construction efficiency.

[0025] The above-mentioned method for reinforcing and preventing grout leakage in composite floor slabs provided by this invention is particularly suitable for the construction of large-span arched composite floor slabs. The locking and fixing system of this method does not rely on the height adjustment of the lower support and can adapt to changes in the height difference of the large-span arched structure, always maintaining the fit between the formwork and the composite slab. It perfectly adapts to the construction scenario of large-span arched composite floor slabs, solving the pain points of traditional formwork's difficulty in fitting the arched surface and the tendency for grout leakage and misalignment in this scenario, without requiring additional formwork adjustment procedures for the arched height difference.

[0026] The above description is merely a preferred embodiment of the present invention. However, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. A construction method for reinforcing and preventing grout leakage in composite floor slabs, characterized in that, Includes the following steps: Step (1): Use a polytetrafluoroethylene template as a plate and strip support template, and pre-drill holes in the polytetrafluoroethylene template according to the fixed points; Step (2): Arrange secondary ribs below the polytetrafluoroethylene template, arrange the bottom channel steel of the fixing device in a direction perpendicular to the secondary ribs, and arrange the main ribs below the bottom channel steel in a direction perpendicular to the bottom channel steel. Step (3): Place the upper pre-embedded cross-connector. One end of the upper pre-embedded cross-connector is connected to two adjacent composite floor slabs, and the other end passes through the PVC tapered nut with the opening facing down, the pre-drilled hole on the upper surface of the polytetrafluoroethylene template, and the bottom channel steel in sequence. Then, lock and fix the upper pre-embedded cross-connector, polytetrafluoroethylene template, secondary rib and main rib to complete the plate and strip reinforcement.

2. A method for reinforcing and preventing grout leakage in composite floor slabs according to claim 1, characterized in that, In step (2), the spacing between adjacent secondary ribs is 100mm.

3. A method for reinforcing and preventing grout leakage in composite floor slabs according to claim 1, characterized in that, In step (2), the secondary beams are made of timber, and the main beams are made of double steel pipes.

4. A construction method for reinforcing and preventing grout leakage of composite floor slabs according to claim 1, characterized in that, In step (3), the upper pre-embedded jumper includes: Supporting steel bars are horizontally connected across two adjacent composite floor slabs; The threaded rod is connected to the support steel bar at one end in the vertical direction, and the other end passes through the PVC tapered nut with the opening facing down, the pre-drilled hole on the upper surface of the polytetrafluoroethylene template, and the bottom channel steel in sequence. The connector is attached to the other end of the lead screw. By tightening the connector, the upper embedded cross-connector, PTFE template, secondary rib and main rib are locked and fixed.

5. A method for reinforcing and preventing grout leakage in composite floor slabs according to claim 4, characterized in that, The connector is a mountain-shaped clip.

6. A construction method for reinforcing and preventing grout leakage of composite floor slabs according to claim 1, characterized in that, The PTFE formwork is fitted to the edge of the composite floor slab, and the gap between the composite floor slab and the PTFE formwork is eliminated by locking.

7. A construction method for reinforcing and preventing grout leakage of composite floor slabs according to any one of claims 1-6, characterized in that, No additional release agent is required when removing the PTFE formwork, and the concrete surface of the slab strip is flat and without misalignment after demolding.

8. The application of the composite floor slab strip reinforcement and anti-leakage construction method according to any one of claims 1-7 in the construction of large-span arched composite floor slab strips.

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