Laminated slab cast-in-place belt slurry leakage prevention formwork structure and construction method

Abstract

The invention belongs to the field of laminated slab construction, and particularly relates to a laminated slab construction joint slurry leakage prevention formwork structure and a construction method.The formwork structure comprises a formwork arranged on the lower side of a laminated slab cast-in-place belt, a sealing strip is arranged on the surface of the included angle between the side face of the formwork and a laminated slab, and a main keel is arranged on the outer side of the sealing strip; the main keels on the two sides of the formwork are fixed to the formwork through clamps. Secondary keels are arranged on the lower side of the main keel at equal intervals, telescopic supporting rods are arranged on the lower sides of the secondary keels, and the lower ends of the telescopic supporting rods are fixed to a scaffold supporting system; the construction method comprises the steps that the formwork is arranged on the lower side of the laminated slab cast-in-place belt; a long-strip-shaped sealing strip is laid at the included angle position of the formwork and the laminated slab in the length direction of the cast-in-place belt; the main keels are pressed on the surfaces of the sealing strips, then the main keels on the two sides of the formwork are clamped through a clamp, and the sealing strips are tightly attached to the side faces of the formwork; secondary keels are uniformly arranged on the lower side of the main keel, and telescopic supporting rods are arranged on the lower sides of the secondary keels, so that the sealing strip is tightly attached to the bottom surface of the laminated slab.

Description

Technical Field

[0001] This invention belongs to the field of composite slab construction technology, specifically relating to a formwork structure and construction method for preventing grout leakage at construction joints of composite slabs. Background Technology

[0002] With the popularization of prefabricated buildings, composite slabs are widely used in floor slab construction because they combine the advantages of stable quality of precast components and good integrity of cast-in-place structures. A cast-in-place strip of about 200mm is reserved between two adjacent composite slabs and cast in one piece with the floor slab. Before pouring, formwork needs to be set up under the cast-in-place strip and then concrete is poured. The cast-in-place concrete is poured into the cast-in-place strip to connect and reinforce the precast slabs and form a smooth composite layer on multiple precast slabs. It has good integrity, high rigidity and is also easy to finish.

[0003] However, in actual construction, due to the possibility of minute deformations or edge bumps that are difficult to detect during the transportation and hoisting of the composite slabs, as well as potential deviations in the on-site formwork erection, irregular gaps often appear between the lower surface of the composite slab and the supporting formwork below. When pouring the cast-in-place concrete strip, cement mortar is very likely to leak out from these gaps, causing a series of problems: First, the leakage leads to the loss of mortar in the cast-in-place concrete, which may cause quality defects such as insufficient strength and honeycomb surface pitting; second, it wastes building materials and increases costs; third, it pollutes the underlying structural surface and the construction environment, which does not meet the requirements of green construction; and fourth, it requires cleaning and repair of the leaked areas later, increasing additional labor and repair costs.

[0004] In the existing technology, common methods to solve the problem of grout leakage are, on the one hand, to increase the width of the template, thereby increasing the contact width between the template and the surface of the composite slab and increasing the flow resistance of the concrete grout; on the other hand, to use consumable sealing materials (such as sponge strips) to fill the contact surface between the template and the composite slab. However, increasing the template width increases material consumption, and the template is prone to bulging under the pressure of concrete, which leads to the instability of the sealing material, making it difficult to adapt to the complex changes in the gaps, and it is not easy to fix. It is also prone to failure under the impact of concrete pouring. Summary of the Invention

[0005] The technical problem to be solved by this invention is that the sealing material is not fixed properly during the construction of cast-in-place strips in composite slabs, which easily leads to grout leakage.

[0006] The technical solution adopted by the present invention to solve the aforementioned problem is as follows: A formwork structure for preventing grout leakage in cast-in-place strips of composite slabs includes a formwork set on the lower side of the cast-in-place strip of the composite slab. A sealing strip is provided on the surface of the angle between the side of the formwork and the composite slab. A main keel is provided on the outer side of the sealing strip. The main keels on both sides of the formwork are fixed to the formwork by clamps. Secondary keels are provided at equal intervals on the lower side of the main keels. Telescopic support rods are provided on the lower side of the secondary keels. The lower end of the telescopic support rods is fixed to the scaffolding support system.

[0007] Compared with the prior art, the present invention employing the above structure has the following advantages: This invention utilizes bidirectional extrusion to fully fix the sealing strip, preventing grout leakage between the composite plate and the template, and reducing problems such as insufficient strength, honeycomb surface, material waste, environmental pollution, poor appearance quality, and high repair costs.

[0008] As a preferred option, a further technical solution to the above structure is: The clamp includes a connecting rod, one end of which is provided with a fixing hook that abuts against the outer surface of the main keel on one side; the other end of the connecting rod is equipped with a movable block, which is provided with a movable hook that abuts against the outer surface of the main keel on the other side.

[0009] The telescopic support rod includes a telescopic rod, the upper end of which is connected to an abutment plate via a universal joint. The abutment plate abuts against the lower surface of the main keel. A locking block is fixed to the lower end of the telescopic rod, and the lower surface of the locking block is provided with a groove that matches the scaffold tube.

[0010] The lower surface of the main keel and the lower surface of the template are on the same plane.

[0011] To address the aforementioned problem, the present invention also provides a construction method based on the composite slab cast-in-place strip anti-leakage formwork structure, which is constructed according to the following steps: The first step is to set up a scaffolding support system under the floor slab, and after the composite slab is installed in place, adjust the scaffolding support system to lift and support the composite slab. The second step is to place the template under the cast-in-place strip of the composite slab, with the required overlap width between the template and the composite slab on both sides. The third step is to lay the long strip of sealing strip along the length of the cast-in-place strip at the angle between the formwork and the composite slab. The fourth step is to press the main keel onto the surface of the sealing strip, so that the cross-section of the sealing strip becomes a curved shape that fits the side and top surface of the main keel. Then, use clamps to clamp the main keels on both sides of the template, so that the sealing strip fits tightly against the side of the template. Fifth step: evenly install secondary keels on the underside of the main keel, and install telescopic support rods on the underside of the secondary keels to squeeze the sealing strip so that the sealing strip is tightly attached to the bottom surface of the composite plate.

[0012] Optionally, the overlap width between the template and the composite board is 10mm-50mm.

[0013] Optionally, the sealing strip can be a rubber sheet, EPE pearl cotton, or polyethylene foam pad.

[0014] Optionally, the lower end of the telescopic support rod is fixed to the scaffolding support system. Attached Figure Description

[0015] Figure 1 This is an overall diagram of the leak-proof structure of the template of this invention; Figure 2 This is an elevation view of the template fixing structure of the present invention; Figure 3 This is a structural diagram of the fixture of the present invention.

[0016] Explanation of reference numerals in the attached drawings: 1. Composite plate; 2. Template; 3. Sealing strip; 401. Main keel; 402. Secondary keel; 5. Clamp; 6. Telescopic support rod; 501. Connecting rod; 502. Movable block; 503. Movable hook; 504. Fixed hook. Detailed Implementation

[0017] The present invention will be further described below with reference to embodiments, which are intended only to provide a better understanding of the invention. Therefore, the examples given do not limit the scope of protection of the present invention.

[0018] See Figure 1 and Figure 3 This invention provides a formwork structure for preventing grout leakage in cast-in-place strips of composite slabs, which is set on the lower side of the cast-in-place strip of composite slab 1. It includes a formwork 2 set on the lower side of the cast-in-place strip of composite slab 1. The feature is that a sealing strip 3 is provided on the surface of the angle between the side of the formwork 2 and the composite slab 1. A main keel 401 is provided on the outer side of the sealing strip 3. The main keels 401 on both sides of the formwork 2 are fixed to the formwork 2 by clamps 5. Secondary keels 402 are provided at equal intervals on the lower side of the main keels 401. Telescopic support rods 6 are provided on the lower side of the secondary keels 402. The lower end of the telescopic support rods 6 is fixed to the scaffolding support system.

[0019] Optionally, the clamp 5 includes a connecting rod 501, one end of which is provided with a fixing hook 504, which abuts against the outer surface of the main keel 401 on one side; the other end of the connecting rod 501 is equipped with a movable block 502, which is provided with a movable hook 503, which abuts against the outer surface of the main keel 401 on the other side. A woodworking clamp can be specifically selected.

[0020] Optionally, the telescopic support rod 6 includes a telescopic rod, the upper end of which is connected to an abutment plate via a universal joint. The abutment plate abuts against the lower surface of the main keel 401. A locking block is fixed to the lower end of the telescopic rod, and the lower surface of the locking block is provided with a groove adapted to the scaffold tube. The number of telescopic support rods 6 corresponds to the number of secondary keels 402. Their lower ends can directly support the scaffolding support system on the floor slab. If there is no scaffolding horizontal tube below the cast-in-place strip, a scaffold tube is added to the scaffolding support system to support the telescopic support rods 6.

[0021] In this design, the main keel 401 is designed on both sides of the template 2. It is used to pressurize and fix the sealing strip 3 and does not have an upward supporting force on the template 2. The secondary keel 402 is used to support the template 2 upward and to squeeze the sealing strip 3 upward. Therefore, the secondary keel 402 is preferably designed so that the lower surface of the main keel 401 is on the same plane as the lower surface of the template 2, so that it can contact the main keel 401 and the template 2 at the same time.

[0022] Meanwhile, the present invention also provides a construction method for preventing grout leakage in the cast-in-place strip of the composite slab 1. The design concept is to use the elastic deformation ability of the sealing strip 3 to fit tightly with the surface of the composite slab 1, thereby solving the problem of grout leakage caused by irregular gaps between the composite slab 1 and the template 2. By applying controllable pressure to the sealing strip 3 from bottom to top and from the outside to the middle, the sealing strip 3 is driven to tightly fill and seal all gaps between the composite slab 1 and the template 2.

[0023] The construction method specifically includes the following steps: The first step is to erect a scaffolding support system under the floor slab. After the composite slab 1 is installed in place, the scaffolding support system is adjusted to prepare for the jacking and support construction of the composite slab 1. As the precast floor slab structure is assembled and fixed, the composite slab 1 must be supported by a scaffolding support system on its underside. The scaffolding support system can only be completely removed after the floor slab is poured and the two sides of the composite slab 1 form an integral structure. Therefore, the scaffolding structure must exist when pouring the cast-in-place strip.

[0024] The second step involves placing template 2 under the cast-in-place strip of the composite slab 1, with the required overlap width on both sides. Template 2 can be made of wood. This invention incorporates a sealing strip 3 that works in conjunction with template 2 to completely seal the gap between the cast-in-place strip and template 2. Therefore, it is unnecessary to widen template 2 to increase the flow resistance of the grout. The overlap width between template 2 and composite slab 1 does not need to be large, as long as they can overlap. Specifically, the overlap width between template 2 and composite slab 1 is 10mm-50mm. This allows for the use of a narrower template 2, saving materials.

[0025] The third step is to lay the long strip of sealing strip 3 along the length of the cast-in-place strip at the angle between the formwork 2 and the composite slab 1. The sealing strip 3 is made of materials with good elasticity, compression set recovery, and corrosion resistance, such as rubber sheets, EPE pearl cotton, or polyethylene foam pads. The thickness can be selected from 10mm to 20mm, and it is non-absorbent or slightly absorbent, allowing it to fit snugly against the gap between the formwork 2 and the composite slab 1. Adjacent sealing strips 3 can be joined by compression to prevent leakage or by overlapping.

[0026] The fourth step involves pressing the main keel 401 onto the surface of the sealing strip 3, causing the cross-section of the sealing strip 3 to become a curved shape that fits against the sides and top of the main keel 401. Then, clamps 5 are used to clamp the main keels 401 on both sides of the template 2, ensuring that the sealing strip 3 is tightly fitted against the sides of the template 2. The sides of the main keel 401 press against the template 2 to compress the sealing strip 3, making the sealing strip 3 tightly abut against the surface of the template 2. The upper surface of the main keel 401 presses against the composite plate 1 to compress the sealing strip 3, making the sealing strip 3 tightly abut against the surface of the composite plate 1. The main keel 401 is aligned with the template 2, and the corners of the main keel 401 are pressed into the angled gap between the template 2 and the composite plate 1, completely sealing the gap in the cast-in-place strip by utilizing the material properties of the sealing strip 3.

[0027] Fifth step, secondary keels 402 are evenly arranged on the lower side of the main keel 401, and telescopic support rods 6 are set on the lower side of the secondary keels 402. The lower end of the telescopic support rods 6 is fixed to the scaffolding support system. The telescopic support rods 6 are used to squeeze the sealing strip 3 so that the sealing strip 3 is tightly attached to the bottom surface of the composite plate 1.

[0028] The principle of force application in this invention: Secondary joists 402 are installed perpendicular to the main joists 401, simultaneously restraining both main joists 401. Both main joists 401 and secondary joists 402 are made of timber, with multiple secondary joist timbers spaced at intervals, and the secondary joist timbers are pressed onto the main joist timbers 401. The main joists 401 and secondary joists 402 together form a frame that uniformly transmits force and provides stable support.

[0029] Below the secondary keel 402 timber, an adjustable telescopic support rod 6 is installed. The lower end of the telescopic support rod 6 is stably supported on the erected scaffold frame. By operating the telescopic support rod 6 (such as rotating the adjusting nut), it is extended, thereby applying an upward pushing force to the secondary keel 402. The upward pushing force is transmitted sequentially through the secondary keel 402 and the main keel 401 to the sealing strip 3. Under the uniform vertical pressure, the sealing strip 3 undergoes elastic deformation, bulges upward, and tightly adheres to the lower surface of the upper composite board 1, filling the vertical gaps caused by unevenness, deformation, or installation errors of the composite board 1.

[0030] Multiple wood clamps are arranged at intervals along the length of the cast-in-place strip and clamped onto the main keel 401 on both sides. By tightening the wood clamps, the main keel 401 on the left side is subjected to a force to the right, and the main keel 401 on the right side is subjected to a force to the left, forming opposing lateral pressure. The lateral pressure is evenly applied to the sealing strip 3 through the main keel 401, causing the rubber sealing strip 3 to deform inward toward the joint between the composite plate 1 and the template 2, further filling any possible lateral gaps, thereby achieving an all-around seal.

[0031] The beneficial effects of this invention are: Reliable sealing effect: By combining vertical tightening and lateral clamping, the sealing strip can be fully deformed to actively fill irregular gaps, providing a tight seal and effectively preventing cement mortar leakage.

[0032] High adaptability: The elastic deformation of the sealing strip can adapt well to the unevenness caused by deformation and impact on the lower surface of the composite plate, and has good versatility.

[0033] Simple and efficient construction: All materials and tools commonly used on construction sites (timber, wood clamps, adjustable support rods) are used, requiring no special processing or complex processes. Assembly and disassembly are quick, improving construction efficiency.

[0034] Low cost: The materials used are inexpensive and reusable, avoiding material waste and subsequent cleaning and repair costs, resulting in significant overall economic benefits.

[0035] Green and environmentally friendly: It fundamentally reduces grout leakage during the pouring process, reduces construction waste and environmental pollution, and conforms to the concept of green construction.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent changes made based on the description and drawings of the present invention are included within the scope of the present invention.

Claims

1. A formwork structure for preventing grout leakage in cast-in-place strips of composite slabs, comprising a formwork (2) disposed on the underside of the cast-in-place strip of the composite slab (1), characterized in that, A sealing strip (3) is provided on the surface of the angle between the side of the template (2) and the composite plate (1). A main keel (401) is provided on the outside of the sealing strip (3). The main keels (401) on both sides are fixed to the template (2) by clamps (5). Secondary keels (402) are provided at equal intervals on the lower side of the main keel (401). Telescopic support rods (6) are provided on the lower side of the secondary keels (402). The lower end of the telescopic support rods (6) is fixed to the scaffolding support system of the composite plate.

2. The composite slab cast-in-place formwork structure with anti-leakage grouting as described in claim 1, characterized in that, The clamp (5) includes a connecting rod (501), one end of which is provided with a fixing hook (504), which abuts against the outer surface of the main keel (401) on one side; the other end of the connecting rod (501) is provided with a movable block (502), which is provided with a movable hook (503), which abuts against the outer surface of the main keel (401) on the other side.

3. The composite slab cast-in-place formwork structure with anti-leakage grouting as described in claim 1, characterized in that, The telescopic support rod (6) includes a telescopic rod, the upper end of which is connected to an abutment plate via a universal joint, the abutment plate abutting against the lower surface of the main keel (401), and a locking block fixed to the lower end of the telescopic rod, the lower surface of which is provided with a groove adapted to the scaffold tube.

4. The composite slab cast-in-place formwork structure with anti-leakage grouting as described in claim 1, characterized in that, The lower surface of the main keel (401) and the lower surface of the template (2) are on the same plane.

5. The construction method for the composite slab cast-in-place strip anti-leakage formwork structure according to claim 1 shall be carried out according to the following steps: The first step is to set up a scaffolding support system on the underside of the floor slab. After the composite slab (1) is installed in place, the scaffolding and support system is adjusted to lift and support the composite slab (1). The second step is to place the template (2) under the cast-in-place strip of the composite slab (1) and set the required overlap width between the template (2) and the composite slab (1) on both sides. Its features , The third step is to lay the long strip of sealing strip (3) along the length of the cast-in-place strip at the angle between the template (2) and the composite slab (1); The fourth step is to press the main keel (401) onto the surface of the sealing strip (3) so that the cross section of the sealing strip (3) becomes a curved shape that fits the side and top surface of the main keel (401). Then, use the clamp (5) to clamp the main keels (401) on both sides of the template (2) so that the sealing strip (3) fits tightly against the side of the template (2). Fifth step, secondary keels (402) are evenly arranged on the lower side of the main keel (401), and telescopic support rods (6) are set on the lower side of the secondary keel (402) to squeeze the sealing strip (3) so that the sealing strip (3) is tightly attached to the bottom surface of the composite plate (1).

6. The construction method according to claim 5, characterized in that, The overlap width between the template (2) and the composite board (1) is 10mm-50mm.

7. The construction method according to claim 5, characterized in that, The sealing strip (3) is a rubber sheet, EPE pearl cotton or polyethylene foam pad.

8. The construction method according to claim 5, characterized in that, The lower end of the telescopic support rod (6) is fixed to the scaffolding support system.

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