A prefabricated middle plate joint sealing structure

Abstract

The utility model relates to building waterproof technology field, concretely disclose a prefabricated middle plate joint sealing structure, this structure sets up the step sealing cavity and the bottom sealant storage tank in prefabricated middle plate piecing side, and both form the sealing system through the joint. The cavity is from top to bottom layer arrangement waterproof mortar layer, the paste seal strip, polyurethane sealant; The inlay type compression seal strip is placed in the joint, and the sealant is pre-filled in the storage tank and is provided with a chamfer. When piecing together adjacent middle plates, the compression seal strip is filled in the joint and the sealant is driven along the joint to form a continuous sealing curtain, realizing the joint full-depth closure. The utility model breaks through the traditional segmented sealing limitation, and the material efficiency is doubled through the pressure activation mechanism, and the waterproof reliability is obviously improved and the maintenance process is simplified.

Description

Technical Field

[0001] This utility model relates to the field of building waterproofing technology, specifically to a sealing structure for the joints of precast slabs. Background Technology

[0002] In the construction of prefabricated subway stations, waterproofing the joints of precast slabs is a crucial aspect of ensuring the sealing performance of the underground structure. Traditional methods employ a layered approach to waterproofing: first, a waterproof mortar leveling layer is laid on the joint surface; then, grout-stopping sealing strips and embedded compression sealing strips are installed sequentially; finally, polyurethane sealant is applied to form a sealed system. However, this approach has three inherent drawbacks:

[0003] 1. Low construction efficiency: The four layers of material require independent construction in stages, and the complex process connections significantly extend the construction cycle of each loop, easily becoming a bottleneck in the progress under overlapping work environments. 2. Large fluctuations in sealing quality: The compaction and continuity of each layer of material are highly dependent on the skill of manual operation. Local wrinkles or breaks are prone to occur during the installation of sealing strips. The thickness of the polyurethane sealant coating is difficult to control evenly, and the interlayer interface bonding strength is significantly affected by the cleanliness of the substrate. Human factors lead to the random distribution of leakage risk points. 3. Insufficient long-term service reliability: Under dynamic loads such as train vibration and foundation settlement, the rigid waterproof mortar layer and the flexible sealing strip generate interfacial shear stress due to the difference in modulus, causing interlayer debonding and forming through-seepage channels. Although existing technologies attempt to optimize material combinations, they have not solved the structural delamination problem of the layered system.

[0004] Statistics show that the above-mentioned layered waterproofing structure has a high construction defect rate, and the repair requires the complete removal of the sealant, causing secondary damage to the main structure. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the existing technology and provide a sealing structure for the joints of precast middle plates that is reliable in sealing, stable in quality and resistant to peeling.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A precast mid-plate joint sealing structure includes a sealing cavity and a sealant storage tank respectively disposed at both ends of the joint;

[0008] The sealing cavity includes multiple cavities, which gradually decrease in size from top to bottom towards the joint, forming a stepped sealing cavity.

[0009] A waterproof mortar layer, a first sealing strip, and a first sealant are sequentially arranged from top to bottom within the plurality of cavities; and the waterproof mortar layer, the first sealing strip, and the first sealant are respectively filled in different cavities;

[0010] A second sealing strip is provided in the joint;

[0011] The sealant reservoir is filled with a second sealant.

[0012] As a further improvement to the above technical solution:

[0013] The sealing cavity and sealant storage tank are directly machined from the joint.

[0014] As a further improvement to the above technical solution:

[0015] The opening of the sealant reservoir away from the joint end is chamfered.

[0016] As a further improvement to the above technical solution:

[0017] The waterproof mortar layer is flush with the top surface of the concrete substrate of the precast slab.

[0018] As a further improvement to the above technical solution:

[0019] The first sealant and the second sealant are polyurethane sealants.

[0020] As a further improvement to the above technical solution:

[0021] The first sealing strip is a stop sealant sealing strip.

[0022] As a further improvement to the above technical solution:

[0023] The second sealing strip is an embedded compression sealing strip.

[0024] Compared with the prior art, the advantages of this utility model are:

[0025] A precast slab joint sealing structure includes sealing cavities and sealant reservoirs respectively disposed at both ends of the joint. Each sealing cavity comprises multiple chambers, which decrease in size progressively towards the joint to form a stepped sealing cavity. A waterproof mortar layer, a first sealing strip, and a first sealant are sequentially disposed within each of the multiple chambers from the sealing cavity to the joint. A second sealing strip is disposed within the joint. The sealant reservoir is filled with a second sealant. This invention mechanically locks the waterproof mortar, the sealing strip, and the polyurethane sealant through the stepped sealing cavity, reducing interlayer delamination. The compressed sealing strip actively fills small micro-cracks, improving pressure resistance and significantly enhancing sealing reliability. Simultaneously, the standardized precast sealing cavity reduces reliance on manual skills; during maintenance, only the surface sealant needs to be replenished at the bottom, avoiding structural demolition and optimizing overall life-cycle costs. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the joint sealing structure when adjacent precast intermediate plates are joined together.

[0027] Figure 2 This is a schematic diagram showing the activated state of the joint sealing structure after adjacent precast slabs are joined together.

[0028] Legend:

[0029] 1. Precast mid-slab; 2. Sealed cavity; 3. Waterproof mortar layer; 4. First sealing strip; 5. Second sealing strip; 6. First sealant; 7. Joint; 8. Sealant storage tank; 9. Second sealant. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1 As shown, this embodiment provides a prefabricated mid-plate joint sealing structure, including a sealing cavity 2 and a sealant storage tank 8 respectively disposed at both ends of the joint 7, the three forming a continuous sealing system.

[0032] The sealing cavity 2 includes multiple cavities, which decrease in size from top to bottom towards the joint 7 to form a stepped sealing cavity 2 arranged in layers from top to bottom; the multiple cavities are provided with a waterproof mortar layer 3, a first sealing strip 4 and a first sealant 6 in sequence from top to bottom towards the joint 7; a second sealing strip 5 is provided in the joint 7; and the sealant storage tank 8 is filled with a second sealant 9.

[0033] In this embodiment, the cross-sectional dimensions of the waterproof mortar layer are 30mm × 50mm; the cross-sectional dimensions of the first sealing strip are 15mm × 35mm; and the first sealant is filled to be flush with the bottom of the sealing cavity, with a cross-sectional dimension of 12mm × 25mm.

[0034] The sealant reservoir has a cross-sectional dimension of 12mm × 25mm, and the opening at the end away from the joint 7 is chamfered, and the interior is filled with a second sealant.

[0035] The sealing cavity 2 and the sealant storage tank 8 are directly machined from the joint 7. The stepped sealing cavity is formed by fixing the stepped steel mold with the side mold during the precast slab casting stage, and its cross-section is stepped with a wider top and a narrower bottom.

[0036] The waterproof mortar layer 3 is flush with the top surface of the concrete substrate of the precast slab 1.

[0037] The first sealant 6 and the second sealant 9 are polyurethane sealants.

[0038] The first sealing strip 4 is a stop seal strip.

[0039] The second sealing strip 5 is an embedded compression sealing strip.

[0040] The joint sealing structure in this embodiment is mainly used for sealing the joints of precast middle slabs in prefabricated subway stations. The construction method is as follows:

[0041] 1. Precast slab processing: a) When casting the precast intermediate slab, a stepped cross-section steel mold is fixed in the side formwork; b) After the concrete has set, the mold is removed to form a stepped sealed cavity;

[0042] 2. On-site assembly preparation: a) Hoist the precast intermediate slabs to the design elevation; b) Adjust the spacing between adjacent intermediate slabs to an appropriate distance.

[0043] 3. Sealing Activation: a) Fill the sealant reservoir with polyurethane sealant; b) Embed the embedded compression sealing strip into the joint, then fill the cavity with polyurethane sealant and the grout-stopping sealing strip in sequence to each stepped cavity opening, and then fill with waterproof mortar until it is flush with the top surface of the board; c) Apply horizontal pressure; d) Observe that the polyurethane sealant ⑥ overflows evenly to form a secondary sealing layer.

[0044] 4. Surface treatment: a) Clean up any excess adhesive; b) Ensure that the adhesive layer outside the seam remains continuous and uniform.

[0045] like Figure 2 The diagram shows the activated state of the joint sealing structure after adjacent precast slabs are joined together. The arrows indicate the joining direction.

[0046] When adjacent precast intermediate plates are joined, a sealing mechanism is activated by applying horizontal pressure, forming a bidirectional pressure sealing structure. When adjacent intermediate plates are joined, the second sealing strip 5 is compressed and deformed vertically to fill the joint 7 in the groove, while the polyurethane sealant 6 is squeezed out of the joint 7 to form a sealing layer.

[0047] When local leakage occurs in the bottom sealant storage tank 8, remove the surface sealant from the leaking area and then inject new sealant to make the new sealant flush with the original sealing layer.

[0048] The above description is merely a preferred embodiment of this utility model, and the protection scope of this utility model is not limited to the above embodiments. For those skilled in the art, improvements and modifications obtained without departing from the technical concept of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A precast mid-plate joint sealing structure, characterized in that: Includes sealing cavities (2) and sealant storage tanks (8) respectively located at both ends of the joint (7); The sealing cavity (2) includes multiple cavities, which decrease in size from top to bottom toward the joint (7) to form a stepped sealing cavity (2). A waterproof mortar layer (3), a first sealing strip (4), and a first sealant (6) are sequentially arranged from top to bottom in multiple cavities; and the waterproof mortar layer (3), the first sealing strip (4), and the first sealant (6) are respectively filled in different cavities; A second sealing strip (5) is provided in the seam (7); The sealant reservoir (8) is filled with a second sealant (9).

2. The precast middle plate joint sealing structure according to claim 1, characterized in that: The opening of the sealant reservoir (8) away from the joint (7) is chamfered.

3. The precast middle plate joint sealing structure according to claim 1, characterized in that: The waterproof mortar layer (3) is flush with the top surface of the concrete substrate of the precast slab (1).

4. The precast middle plate joint sealing structure according to claim 1, characterized in that: The first sealant (6) and the second sealant (9) are polyurethane sealants.

5. The precast slab joint sealing structure according to claim 1, characterized in that: The first sealing strip (4) is a grout sealing strip.

6. The precast middle plate joint sealing structure according to claim 5, characterized in that: The second sealing strip (5) is an embedded compression sealing strip.

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