Anti-cracking connecting structure of precast slab

Abstract

The utility model discloses a prefabricated slab anti -cracking connecting structure relates to the technical field of assembly building, and this prefabricated slab anti -cracking connecting structure includes: contact board, is symmetrically arranged in the butt joint end surface of prefabricated slab and is fixedly connected in prefabricated slab, and the contact board is the wave -shaped tenon and mortise structure, and the concave -convex surface of wave -shaped tenon and mortise structure mutually engages, alloy ring, is set in the circumferential outside of contact board, prestressed anchor rod, the prestressed anchor rod is worn in prefabricated slab, bifurcated anchor bar, bifurcated anchor bar includes the main stem and bifurcated anchor head, and bifurcated anchor head sets up in one end of main stem and is connected in angle with main stem, and the end of bifurcated anchor head embeds adjacent prefabricated slab. The utility model through the wave -shaped mortise and tenon structure of contact board realizes the multiaxial constraint of adjacent prefabricated slab when being stressed, disperses the stress at the gap, reduces the cracking risk, and simultaneously realizes stress even transmission through bifurcated anchor bar and prestressed anchor rod, improves the seismic resistance and durability of link structure, realizes the effect of anti -cracking and easy construction.

Description

Technical Field

[0001] This utility model relates to the field of prefabricated building technology, and in particular to a prefabricated panel anti-cracking connection structure. Background Technology

[0002] With the increasing maturity of prefabricated construction, more and more buildings are adopting prefabricated structures. Various prefabricated components are prefabricated in factories, and after being transported to the construction site, they are assembled to complete the project, greatly improving the construction speed. Among them, prefabricated slabs were used as floor slabs in early buildings, and they have now become the main product among prefabricated components. In actual use, multiple prefabricated slabs need to be connected together for use.

[0003] However, the joints between precast slabs are prone to cracking due to stress concentration, shrinkage deformation, or external loads, affecting the integrity and durability of the structure. Traditional precast slab connection methods often use rigid connections or simple overlapping structures, which are difficult to effectively adapt to deformation caused by temperature changes, foundation settlement, or dynamic loads, leading to frequent cracking problems at the joints of precast slabs.

[0004] Therefore, there is a need for a precast slab anti-cracking connection structure that is simple in structure, easy to construct, and can adapt to the deformation of precast slabs. Utility Model Content

[0005] The main purpose of this utility model is to provide a precast slab anti-cracking connection structure, which aims to solve the problem that existing precast slab connections are prone to cracking.

[0006] To achieve the above objectives, the precast slab anti-cracking connection structure proposed in this utility model is applied to precast slabs and includes:

[0007] The contact plate is symmetrically arranged on the mating end face of the precast slab and fixedly connected to the precast slab. The contact plate has a wavy tenon and groove structure, and the concave and convex surfaces of the wavy tenon and groove structure interlock with each other.

[0008] An alloy ring, which is sleeved on the circumferential outer side of the contact plate;

[0009] A prestressed anchor rod is inserted through the precast slab. The prestressed anchor rod also includes tension nuts, which are disposed at both ends of the prestressed anchor rod. The prestressed anchor rod is fixedly connected to the contact plate through the tension nuts.

[0010] The bifurcated anchor bar includes a main trunk and a bifurcated anchor head. The main trunk extends axially along the contact plate and is disposed within the contact plate. The bifurcated anchor head is disposed at one end of the main trunk and is connected to the main trunk at an angle. The end of the bifurcated anchor head is embedded in the adjacent precast slab.

[0011] Preferably, the contact plate is made of flexible concrete incorporating polypropylene fibers, wherein the length of the polypropylene fibers is 12-18 mm and the dosage is 0.5%-1.2% of the concrete volume.

[0012] Preferably, the angle between the forked anchor head and the main trunk is 30° to 60°, and the end of the forked anchor head is provided with a bending structure.

[0013] Preferably, the contact plate further includes an elastic filler layer, which is bonded to the side of the contact plate away from the precast plate, and the elastic filler layer is made of either neoprene rubber or polyurethane foam.

[0014] Preferably, the inner side of the alloy ring is provided with a serrated groove, and the outer side of the elastic filling layer is provided with a protrusion corresponding to the serrated groove, and the alloy ring is engaged with the elastic filling layer.

[0015] Preferably, the crest height of the wave-shaped tenon and groove structure on the contact plate is 20~30mm, the trough spacing is 50~80mm, and the ratio of the curvature radius of the crest to the trough is 1:1.2~1:1.5.

[0016] Preferably, the precast slab anti-cracking connection structure further includes a threaded sleeve, which is disposed inside the precast slab, and the main trunk of the bifurcated anchor bar is detachably connected to the prestressed anchor rod through the threaded sleeve.

[0017] This invention's precast slab crack-resistant connection structure utilizes the wavy tenon and mortise structure of the contact plate to create multi-directional constraints between adjacent precast slabs under stress, dispersing stress at the joint and reducing the risk of cracking. The prestressed anchor rods and contact plate form a tensile system, further enhancing the overall connection rigidity and preventing crack propagation due to load or temperature deformation. This invention offers advantages such as crack resistance, earthquake resistance, and ease of construction, solving the problem of cracking easily occurring at existing precast slab connection points. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the precast slab anti-cracking connection structure according to an embodiment of the present invention;

[0020] Figure 2 This is a cross-sectional structural diagram of the contact plate according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the contact plate in one embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure of the elastic filling layer in one embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of an alloy ring according to an embodiment of the present invention.

[0024] Explanation of icon numbers:

[0025] label name label name 1000 Precast slab anti-cracking connection structure 100 Contact plate 110 elastic filler layer 200 alloy ring 300 Prestressed anchor bolts 310 Tensioner nut 400 bifurcated anchor bar 410 trunk 420 bifurcated anchor head 500 Threaded sleeve 2000 precast slabs

[0026] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] It should be noted that all directional indicators in this embodiment are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicator will also change accordingly.

[0029] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0030] In existing technologies, precast slabs are mostly connected using rigid connections or simple overlapping structures, which are difficult to effectively adapt to deformation caused by temperature changes, foundation settlement, or dynamic loads, leading to cracking at the joints of precast slabs. Common anti-cracking measures include adding steel mesh, using elastic sealant, or setting expansion joints, but these methods have problems such as complex construction, high cost, or poor long-term effectiveness. For example, although steel mesh can enhance the overall integrity, it still cannot completely prevent micro-cracks caused by shrinkage stress; elastic sealant is prone to aging and has poor durability. In addition, some connection structures in existing technologies are overly complex, which is not conducive to rapid on-site installation and affects construction efficiency.

[0031] Based on this, such as Figures 1 to 5 As shown. This utility model proposes a crack-resistant connection structure 1000 for precast slab 2000, applied to precast slab 2000, including: a contact plate 100, the contact plates 100 being symmetrically arranged on the mating end faces of the precast slab 2000 and fixedly connected to the precast slab 2000, the contact plates 100 having a wavy tenon-and-groove structure, the concave and convex surfaces of the wavy tenon-and-groove structure interlocking with each other; an alloy ring 200, the alloy ring 200 being sleeved on the circumferential outer side of the contact plate 100; and a prestressed anchor rod 300, the prestressed anchor rod 300 being inserted through the precast slab 2000, the prestressed anchor rod... 300 also includes tension nuts 310, which are disposed at both ends of the prestressed anchor rod 300, and the prestressed anchor rod 300 is fixedly connected to the contact plate 100 through the tension nuts 310; and a bifurcated anchor bar 400, which includes a main bar 410 and a bifurcated anchor head 420. The main bar 410 extends along the axial direction of the contact plate 100 and is disposed within the contact plate 100. The bifurcated anchor head 420 is disposed at one end of the main bar 410 and is connected to the main bar 410 at an angle. The end of the bifurcated anchor head 420 is embedded in the adjacent precast slab 2000.

[0032] In this embodiment, as Figures 1-2 As shown, the contact plate 100 is displayed in a half-section window for ease of public viewing. When connecting two precast slabs 2000, the contact plates 100 on the two precast slabs 2000 are positioned opposite each other and then cement is poured into them. After curing, the two precast slabs 2000 are joined together. Specifically, the contact plate 100 and the precast slab 2000 are cast in layers; that is, when casting the precast slabs 2000 in the mold, the contact plate 100 is poured onto the mating end faces of the precast slabs 2000. For example... Figure 3As shown, the outer side of the contact plate 100 features an interlaced wavy tenon-and-groove structure. When two adjacent precast slabs 2000 are connected, the interlaced wavy tenon-and-groove structure increases the contact area and forms a multi-directional interlocking, dispersing shear and shear stresses and reducing the risk of cracking at the joint between the two adjacent precast slabs 2000. The alloy ring 200 is made of nickel-titanium alloy and is fitted around the circumferential outer side of the contact plate 100, extending a certain distance. When two adjacent precast slabs 2000 are connected, the alloy ring 200 fits precisely at the joint. During temperature changes, the alloy ring 200 absorbs the deformation caused by thermal expansion and contraction. At low temperatures, the alloy ring 200 contracts to tighten the joint, and at high temperatures, it expands to release stress, enhancing structural stability. Prestressed anchor rods 300 penetrating the precast slabs 2000 are prestressed at both ends and locked by tension nuts 310, forming an integral tensile skeleton and enhancing mechanical properties. In detail, the phase transformation temperature of the alloy ring 200 is set to the annual average temperature of the construction site ±10℃, the ring thickness is 3~5mm, the ring width is 0.5~1cm, the surface of the prestressed anchor rod 300 is threaded, and the pre-tightening force of the tensioning nuts 310 at both ends is 40%~60% of the anchor rod yield strength.

[0033] It is understandable that prestressed anchor rods 300 are pre-embedded when casting precast slab 2000 and contact plates 100 are cast at both ends of precast slab 2000. In another embodiment, the contact plates 100 are prepared by spraying concrete onto the mating end face of precast slab 2000 after precast slab 2000 is prepared and thoroughly dried. The concrete prepared by spraying needs to be ground and cured with precast slab 2000.

[0034] In one embodiment, the contact plate 100 is made of flexible concrete incorporating polypropylene fibers, the polypropylene fibers being 12-18 mm in length and the amount incorporated being 0.5%-1.2% of the concrete volume.

[0035] In this embodiment, the contact plate 100 and the precast plate 2000 are cast in layers. The range of flexible concrete is 5cm from the butt joint of the precast plate 2000 (i.e., within 10cm on both sides from the center of the joint). Flexible concrete inhibits cracks from spreading from the edge of the joint into the plate and reduces the risk of cracking caused by sudden changes in stiffness.

[0036] In one embodiment, the angle between the forked anchor head 420 and the main trunk 410 is 30° to 60°, and the end of the forked anchor head 420 is provided with a bending structure.

[0037] In this embodiment, there are multiple branched anchor heads 420, which are staggered along the circumference of the main trunk 410 to form a tree-like structure. The ends of the branched anchor heads 420 are radially distributed and embedded into adjacent precast slabs 2000. The tree-like distributed branched anchor heads 420 enhance pull-out resistance and improve mechanical properties. The bending structure of the branched anchor heads 420 increases the concrete bonding area and improves the anchorage load.

[0038] In one embodiment, such as Figure 4 As shown, the contact plate 100 also includes an elastic filler layer 110, which is bonded to the side of the contact plate 100 away from the precast plate 2000. The elastic filler layer 110 is made of either neoprene rubber or polyurethane foam.

[0039] In this embodiment, a gap is formed after the two precast slabs 2000 are connected. The operator fills the gap by applying or pasting an elastic filler layer 110 onto the surface of the corrugated tongue and groove structure. The elastic filler layer 110 has a compression rebound rate of ≥80%, which is used to absorb the micro-displacement at the joint through its own deformation. The joint changes caused by concrete shrinkage and creep can be absorbed by the elastic filler layer 110, which is used to absorb the deformation caused by thermal expansion and contraction during temperature changes, thus avoiding stress accumulation.

[0040] In another embodiment, the elastic filling layer 110 is formed after the two prefabricated panels 2000 are connected and a gap is formed between the two contact panels 100. Then, an operator fills the gap with a foamed elastic material to form the elastic filling layer 110.

[0041] In one embodiment, the inner side of the alloy ring 200 is provided with a serrated groove, and the outer side of the elastic filling layer 110 is provided with a protrusion corresponding to the serrated groove. The alloy ring 200 and the elastic filling layer 110 are engaged and connected.

[0042] In this embodiment, as Figure 5 As shown, the serrated groove has a tooth height of 3mm, a tooth pitch of 8mm, and a tooth angle of 60°. The interference fit between the serrated groove of the alloy ring 200 and the protrusion of the elastic filling layer 110 is 0.5~1mm. The serrated groove of the alloy ring 200 and the serrations between the elastic filling layer 110 form an interlocking structure, which makes the alloy ring 200 and the elastic layer deform together, and improves the interface peeling resistance.

[0043] In one embodiment, the crest height of the wave-shaped tenon and groove structure on the contact plate 100 is 20~30mm, the trough spacing is 50~80mm, and the ratio of the curvature radius of the crest to the trough is 1:1.2~1:1.5.

[0044] In this embodiment, the wavy tenon can avoid stress concentration caused by sharp corners, while increasing the contact area, which can improve the load transfer efficiency of the contact surface compared to a flat surface.

[0045] In one embodiment, the crack-resistant connection structure 1000 of the precast slab 2000 further includes a threaded sleeve 500, which is disposed inside the precast slab 2000. The main stem 410 of the bifurcated anchor bar 400 and the prestressed anchor rod 300 are detachably connected through the threaded sleeve 500.

[0046] In this embodiment, the threaded sleeve 500 is used to connect the prestressed anchor rod 300 that penetrates the precast slab 2000 and the bifurcated anchor bar 400 that passes through the contact plate 100, thereby improving the anti-slip capability.

[0047] This invention's precast slab crack-resistant connection structure utilizes the wavy tenon and mortise structure of the contact plate to create multi-directional constraints between adjacent precast slabs under stress, thereby dispersing stress at the joint and reducing the risk of cracking. Prestressed anchor rods inserted into the precast slabs, together with the contact plate and bifurcated anchor bars, form a tensile system, further enhancing the overall connection stiffness and preventing crack propagation due to load or temperature deformation. The bifurcated anchor bars embedded at their ends in adjacent precast slabs also strengthen pull-out resistance. Therefore, this invention offers advantages such as crack prevention, earthquake resistance, and ease of construction, solving the problem of cracking easily occurring at existing precast slab connection points.

[0048] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the concept of the present utility model and using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present utility model.

Claims

1. A precast panel anti-cracking connection structure, characterized in that, Applied to precast slabs, including: The contact plate is symmetrically arranged on the mating end face of the precast slab and fixedly connected to the precast slab. The contact plate has a wavy tenon and groove structure, and the concave and convex surfaces of the wavy tenon and groove structure interlock with each other. An alloy ring, which is sleeved on the circumferential outer side of the contact plate; A prestressed anchor rod is inserted through the precast slab. The prestressed anchor rod also includes tension nuts, which are disposed at both ends of the prestressed anchor rod. The prestressed anchor rod is fixedly connected to the contact plate through the tension nuts. The bifurcated anchor bar includes a main trunk and a bifurcated anchor head. The main trunk extends axially along the contact plate and is disposed within the contact plate. The bifurcated anchor head is disposed at one end of the main trunk and is connected to the main trunk at an angle. The end of the bifurcated anchor head is embedded in the adjacent precast slab.

2. The precast panel crack control joint of claim 1, wherein, The contact plate is made of flexible concrete incorporating polypropylene fibers, wherein the length of the polypropylene fibers is 12-18 mm and the dosage is 0.5%-1.2% of the concrete volume.

3. The precast slab anti-cracking connection structure as described in claim 1, characterized in that, The angle between the forked anchor head and the main trunk is 30° to 60°, and the end of the forked anchor head is provided with a bending structure.

4. The precast panel crack control joint of claim 1, wherein, The contact plate also includes an elastic filler layer, which is bonded to the side of the contact plate away from the precast plate. The elastic filler layer is made of either neoprene rubber or polyurethane foam.

5. The precast panel crack control joint structure of claim 4, wherein, The inner side of the alloy ring is provided with a serrated groove, and the outer side of the elastic filling layer is provided with a protrusion corresponding to the serrated groove. The alloy ring and the elastic filling layer are engaged and connected.

6. The precast panel crack control joint structure of claim 1, wherein, The wave crest height of the wavy tenon-groove structure on the contact plate is 20~30mm, the trough spacing is 50~80mm, and the ratio of the radius of curvature of the wave crest to the trough is 1:1.2~1:1.

5.

7. The precast panel crack control joint structure of claim 1, wherein, The precast slab anti-cracking connection structure also includes a threaded sleeve, which is disposed inside the precast slab, and the main trunk of the bifurcated anchor bar is detachably connected to the prestressed anchor rod through the threaded sleeve.

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