A precast panel capable of applying prestress to post-installed joints

Abstract

The scheme belongs to the field of structural engineering, and particularly relates to a prefabricated panel capable of applying prestress to post-poured joints, which comprises a panel main body, a steel reinforcement cage, permanent prestress bundles, temporary prestress bundles and a prestress release assembly; the steel reinforcement cage is embedded in the panel main body, and a local structure thereof extends out of the panel main body; the permanent prestress bundles are embedded in the panel main body and arranged along the main stress direction of the prefabricated panel; the temporary prestress bundles are embedded in the panel main body and arranged along the main stress direction of the prefabricated panel; the two ends of the temporary prestress bundles extend out of the panel main body; the prestress release assembly is installed at the end of the temporary prestress bundle and fixedly connected with the steel reinforcement cage. Compared with the prior art, the scheme solves the problem that the post-poured joints between prefabricated panels cannot be applied with prestress and are prone to cracks during use. The scheme generates a cooperative deformation between the prefabricated panel and the post-poured joint through the prestress technology, so that the post-poured joint forms a compressive stress reserve to avoid cracking.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of structure engineering, concretely relates to a prefabricated panel capable of exerting prestress on post-poured joint. BACKGROUND

[0002] In recent years, with the continuous deepening of the high-quality development direction of China's engineering construction industry, the continuous popularization and breakthrough of industrialized construction mode, the prefabricated structure as a structure form with industrialized construction characteristics is more and more widely applied.

[0003] When the prefabricated panel is used, the post-poured wet joint between each prefabricated panel is connected with the beam below through shear nails to form an integral whole; for the negative bending moment area, the internal tension prestressed beam is often applied to the prefabricated panel to generate compressive stress reserve to limit cracking; the prior art: CN219637600U discloses a reinforcing structure of a prefabricated prestressed concrete pavement panel, which optimizes the design of the reinforcing structure to improve the impact resistance, wear resistance and durability of the prefabricated pavement panel, and reduces and avoids the occurrence of panel cracking and damage; CN105863088A discloses a design and construction process of super-long floor slab concrete post-poured joint, which utilizes the sufficient extension capacity of the post-poured joint and the shrinkage prestress to realize the release of the floor slab concrete temperature stress and the resistance to residual shrinkage stress, and ensures that the super-long floor slab does not crack; CN218149155U discloses a post-poured joint of a super-long structure reinforced concrete composite slab, which installs the steel bars on the capillary tube capsules containing liquid adhesive, so that the liquid adhesive can be used for bonding when cracks occur, thereby realizing the self-healing function of the cracks.

[0004] However, in the prior art, the post-poured joint for connecting each prefabricated panel cannot exert prestress, so that cracks are concentrated in the width range of the post-poured joint during use. Therefore, it is urgent to study a technology capable of exerting prestress on the post-poured joint to improve the durability of the prefabricated structure and fully release its advantages. UTILITY MODEL CONTENTS

[0005] The utility model aims at solving at least one of the above problems and provides a prefabricated panel capable of exerting prestress on a post-poured joint, so as to solve the problem that the post-poured joint between prefabricated panels in the prior art cannot exert prestress and is prone to cracks during use. The present application utilizes prestress technology to generate cooperative deformation between the prefabricated panel and the post-poured joint, so that the post-poured joint forms compressive stress reserve.

[0006] The utility model achieves the above-mentioned purpose through the following technical scheme:

[0007] A prefabricated panel capable of exerting prestress on a post-poured joint, comprising a panel body, a steel cage, a permanent prestressed beam, a temporary prestressed beam and a prestress release assembly.

[0008] The steel reinforcement cage is embedded in the panel body, and a partial structure of the steel reinforcement cage extends out of the panel body;

[0009] The permanent prestress beam is embedded in the panel body, and the permanent prestress beam is arranged along the main stress direction of the prefabricated panel;

[0010] The temporary prestress beam is embedded in the panel body, and the temporary prestress beam is arranged along the main stress direction of the prefabricated panel; both ends of the temporary prestress beam extend out of the panel body;

[0011] The prestress release assembly is installed at the end of the temporary prestress beam, and the prestress release assembly is further fixedly connected with the steel reinforcement cage.

[0012] Preferably, the thickness of the panel body is 240-400 mm, the length is 4000-12000 mm, and the width is 1000-4000 mm;

[0013] The panel body is a concrete prefabricated panel, and the panel body is made of a concrete material with a strength grade of C40 or above.

[0014] Preferably, the steel reinforcement cage is composed of steel bars arranged in a staggered manner, including transverse steel bars arranged along the length direction of the panel body and longitudinal steel bars arranged along the width direction of the panel body.

[0015] Preferably, in the steel reinforcement cage, the transverse steel bars and the longitudinal steel bars are fixedly welded at the staggered positions to form an integral frame type steel reinforcement cage.

[0016] Preferably, in the steel reinforcement cage, the transverse steel bars and the longitudinal steel bars are respectively arranged in a two-layer structure.

[0017] Preferably, in the steel reinforcement cage, the steel bars are in a U-shaped structure or a hook-shaped structure, both ends of the steel bars are embedded in the panel body, and the corner of the steel bars extends out of the panel body.

[0018] Preferably, in the steel reinforcement cage, the vertical distance from the farthest end of the steel bar extending out of the panel body to the surface of the panel body is not less than 50 mm.

[0019] Preferably, the permanent prestress beam and the temporary prestress beam are arranged alternately and in an axial symmetry in the panel body.

[0020] Preferably, the permanent prestress beam is a steel strand, a steel wire rope or a steel rod, and the end of the permanent prestress beam is fixed to the panel body through a flat anchor; the temporary prestress beam is a steel strand, a steel wire rope or a steel rod, and one end of the temporary prestress beam is fixed to the panel body through a permanent anchor, and the other end of the temporary prestress beam is fixed to the panel body through a prestress release assembly.

[0021] The permanent prestress beam and the temporary prestress beam are located at the center of the prefabricated panel along the thickness direction.

[0022] Preferably, the prestress release assembly comprises a steel frame and a tensioning bolt.

[0023] The steel frame is embedded in the panel body, and the steel frame is welded and fixed with the steel reinforcement cage.

[0024] The tensioning bolt is threadedly connected with the anchor head at the end of the temporary prestress beam.

[0025] The working principle of the utility model is as follows:

[0026] The scheme is based on the principles of modular construction and forced cooperative deformation: the temporary prestress beam is tensioned to generate forced compression deformation before the prefabricated panel is installed, and the temporary prestress beam is released after the installation to the beam and the completion of the post-cast joint, so that the prefabricated panel and the post-cast joint generate cooperative deformation, that is, a part of the compression of the prefabricated panel rebounds, and thus the post-cast joint is extruded by the prefabricated panels to form compression stress reserve.

[0027] Compared with the prior art, the utility model has the following beneficial effects:

[0028] The post-cast joint of the conventional prefabricated panel cannot be applied with prestress, and thus the cracks are concentrated in the width range of the post-cast joint, while the scheme of the utility model can apply pre-compression stress to the post-cast joint to improve the overall crack resistance of the concrete panel. Specifically, the prestress release assembly is used in cooperation with the temporary prestress beam, and before the prefabricated panel is combined with the lower alloy beam / concrete beam / wood beam, the temporary prestress beam is first tensioned to make the prefabricated panel generate forced compression deformation; after all the prefabricated panels are installed and the post-cast joint between the prefabricated panels is poured to reach the age, the temporary prestress beam is released by adjusting the prestress release assembly, so that a part of the forced compression deformation of the prefabricated panel rebounds to the post-cast joint and is pressed into compression stress for storage. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a plan structure schematic view of the prefabricated panel (prestress beam perspective) which can apply prestress to the post-cast joint.

[0030] Figure 2 It is a plan structure schematic view of the arrangement mode of the steel reinforcement cage in the prefabricated panel which can apply prestress to the post-cast joint.

[0031] Figure 3 Structure side view of prefabricated panel which can apply prestress to post-pouring joint;

[0032] Figure 4 Structure perspective view of prefabricated panel which can apply prestress to post-pouring joint;

[0033] Figures 5-8 Structure view of prefabricated panel which can apply prestress to post-pouring joint assembled on beam, wherein, Figure 5 the prefabricated panel is formed, Figure 6 the prestress is tensioned, Figure 7 the prefabricated panel is installed on the beam, Figure 8 the post-pouring joint is poured and tensioned;

[0034] In the figure: 1-panel body; 2-steel cage; 3-permanent prestress beam; 4-temporary prestress beam; 5-prestress release assembly; 6-beam. DETAILED DESCRIPTION

[0035] The utility model will be described in detail below in combination with the drawings and specific embodiments. The embodiments are implemented on the premise of the technical scheme of the utility model, and detailed implementation modes and specific operation processes are given, but the protection scope of the utility model is not limited to the following embodiments.

[0036] EMBODIMENT

[0037] A prefabricated panel which can apply prestress to post-pouring joint, as shown in the figure, comprises a panel body 1, a steel cage 2, a permanent prestress beam 3, a temporary prestress beam 4 and a prestress release assembly 5. Figures 1-8

[0038] The steel cage 2 is embedded in the panel body 1, and part of the structure of the steel cage 2 extends out of the panel body 1.

[0039] The permanent prestress beam 3 is embedded in the panel body 1, and the permanent prestress beam 3 is arranged along the main stress direction of the prefabricated panel.

[0040] The temporary prestress beam 4 is embedded in the panel body 1, and the temporary prestress beam 4 is arranged along the main stress direction of the prefabricated panel. The two ends of the temporary prestress beam 4 extend out of the slot holes of the panel body 1, one end is permanently anchored to the panel body 1, and the other end is temporarily anchored to the panel body 1 through the prestress release assembly 5.

[0041] The prestress release assembly 5 is installed at the end of the temporary prestress beam 4, and the prestress release assembly 5 is also fixedly connected with the steel cage 2.

[0042] More specifically, in the embodiment, ​

[0043] A precast panel that can apply prestress to post-cast joints, such as Figure 1 and Figure 2 and Figure 3 and Figure 4 and Figure 5 and Figure 6 and Figure 7 and Figure 8 As shown, the structure comprises five parts: a precast concrete panel body 1, a reinforcing cage 2 embedded inside the panel body 1, permanent prestressing tendons 3, temporary prestressing tendons 4, and a prestressing release assembly 5. The internal reinforcing cage 2 consists of longitudinal and transverse reinforcing bars, with two layers in each direction. These bars form the framework of the reinforcing cage 2 within the concrete panel body 1 and limit crack propagation. The permanent prestressing tendons 3 and temporary prestressing tendons 4 are arranged along the main structural stress direction of the precast panel and at the height of the central axis in the thickness direction within the precast panel / panel body 1 to avoid eccentric stress. The prestressing release assembly 5 is used in conjunction with the temporary prestressing tendons 4. The prestressing release assembly 5 is located at one end of the temporary prestressing tendon 4, near the edge of the panel body 1, and welded to the internal reinforcing bars through a steel frame. The tensioning bolts within the assembly are threadedly connected to the anchor heads of the temporary prestressing tendons 4.

[0044] Furthermore, the precast concrete panel is a flat rectangular prism. Its thickness can be selected from 240mm to 400mm according to actual design requirements, its length can be selected from 4000mm to 12000mm according to actual requirements, and its width can be selected from 1000mm to 4000mm according to actual requirements. The concrete grade of the precast panel should be C40 or higher.

[0045] Furthermore, the reinforcing cage 2 inside the panel body 1 has a total of four layers in the thickness direction, with two layers arranged along the length direction and two layers arranged along the width direction, and the two are arranged in an alternating manner. The longitudinal and transverse reinforcing bars are spot-welded together at their intersections to form an integral frame. The outermost part of the reinforcing cage 2 extends from the panel body 1, and the distance (protective layer thickness) between its outermost end and the surface of the panel body 1 should not be less than 50mm. Even further, the reinforcing bars have a U-shaped or hook-shaped structure. The upper layer of reinforcing bars extends from the side of the panel body 1 and bends back externally before re-inserting into the panel body 1 to form the lower layer of reinforcing bars. This bend-back portion exposed outside the concrete panel body 1 can be connected to other precast panels to form an integral whole after the precast panel is embedded in the post-cast joint.

[0046] Further, the embedded permanent prestressed beam 3 is arranged along the main stress direction of the structure of the prefabricated panel, symmetrically arranged in the length direction (axis) of the prefabricated panel, and arranged alternately with the temporary prestressed beam 4. The permanent prestressed beam 3 can be a steel strand, a steel wire rope or a steel rod, and the end is fixed by a flat anchor to match the small thickness of the prefabricated concrete panel body 1. The permanent prestressed beam 3 is arranged at the center of the thickness of the concrete panel body 1 to avoid eccentric moment generated by tensioning on the concrete panel body 1. In addition, a through hole in the thickness direction can be formed at the fixed position of the two ends of the permanent prestressed beam 3 as needed.

[0047] Further, the embedded temporary prestressed beam 4 is arranged along the main stress direction of the structure of the prefabricated panel, symmetrically arranged in the length direction (axis) of the prefabricated panel, and arranged alternately with the permanent prestressed beam 3. The temporary prestressed beam 4 can be a steel strand, a steel wire rope or a steel rod, and the two ends are arranged in the groove of the panel body 1, wherein one end is fixed by a flat anchor to match the small thickness of the prefabricated concrete panel body 1. The temporary prestressed beam 4 is arranged at the center of the thickness of the concrete panel body 1 to avoid eccentric moment generated by tensioning on the concrete panel body 1. One end of the temporary prestressed beam 4 is a permanent anchor (flat anchor), and the other end is connected to the panel body 1 through a prestress release assembly 5 and forms a temporary anchor with the side wall of the panel body 1.

[0048] Further, the prestress release assembly 5 has tensioning and untensioning functions to realize prestress storage and release. It is specifically composed of a square steel frame and a tensioning bolt: the square steel frame is embedded in the interior of the concrete prefabricated panel body 1 and is welded and fixed with the steel reinforcement cage 2; the tensioning bolt is screwed with the end anchor head of the temporary prestressed beam 4, and the tightness is adjusted by rotating to realize tensioning and untensioning.

[0049] The construction of the prefabricated panel capable of applying prestress to the post-poured joint is realized by the following steps:

[0050] Step one: prefabricated panel forming:

[0051] In the prefabricated factory, the concrete prefabricated panel body 1 is poured through a mold, wherein the internal steel reinforcement cage 2 and the linear type and anchor position of the permanent prestressed beam 3 and the temporary prestressed beam 4 are positioned in the mold before pouring, and then pouring is performed. During pouring, measures such as vibration are paid attention to. After the prefabricated panel is formed, it is stored for more than six months before prestress tensioning and installation. The purpose of this measure is to release most of the shrinkage effect to reduce the shrinkage stress in the later period, and to make the subsequent load creep effect as small as possible.

[0052] Step two: prestress tensioning of prefabricated panel:

[0053] The permanent prestress beam 3 and the temporary prestress beam 4 in the prefabricated panel are tensioned in the order of the permanent prestress beam 3 first and then the temporary prestress beam 4, and specifically, tensioned in a symmetrical manner in the length direction of the prefabricated panel.

[0054] Step three: prefabricated panel installation and connection:

[0055] The prefabricated panel is hoisted to a designated position on the beam 6, without any temporary connection to limit the free deformation of the prefabricated panel, and only rests on the beam 6.

[0056] Step four: pre-compression stress on post-pouring joint:

[0057] The post-pouring wet joint is poured, and after the post-pouring joint is coagulated, the prefabricated panels and the beam 6 are connected to form a reliable whole. After the post-pouring joint reaches the age, the temporary prestress beam 4 in the prefabricated panel is released by the prestress release assembly 5, and at this time, the cooperative deformation will make the post-pouring joint be squeezed by the prefabricated panels and stored in the pre-compression stress.

[0058] The prefabricated panel provided by the scheme can apply pre-stress to the post-pouring joint, solves the problem that the post-pouring joint of the existing prefabricated panel cannot apply pre-compression stress, and causes cracks to appear in the post-pouring joint range during operation. The prefabricated panel is based on the principles of modular construction and forced cooperative deformation, and is matched with the temporary prestress beam 4 through the prestress release assembly 5. The temporary prestress beam 4 is tensioned to produce forced compression deformation before the prefabricated panel and the lower alloy beam / concrete beam / wood beam are installed. After the prefabricated panel is installed on the beam 6 and the wet joint post-pouring is completed and reaches the age, the prestress release assembly 5 is adjusted to release the temporary prestress beam 4, so that the prefabricated panel and the post-pouring joint produce cooperative deformation, that is, a part of the compression amount of the prefabricated panel rebounds, and the post-pouring joint is squeezed by the prefabricated panels to form a compression stress reserve. The structure of the scheme can apply pre-compression stress to the post-pouring joint, improve the crack resistance of the whole concrete prefabricated panel, and provide an effective and novel solution for improving the durability of the prefabricated panel of the assembled structure.

[0059] The above description of the embodiments is for the convenience of those skilled in the art to understand and use the utility model. Those skilled in the art can obviously make various modifications to these embodiments, and apply the general principles described herein to other embodiments without creative labor. Therefore, the utility model is not limited to the above embodiments, and those skilled in the art can make improvements and modifications within the scope of the utility model without departing from the scope of the utility model.

Claims

1. A precast panel capable of applying prestress to post-cast joints, characterized in that, It includes the panel body (1), the steel cage (2), the permanent prestressed tendons (3), the temporary prestressed tendons (4), and the prestress release assembly (5); The steel cage (2) is embedded inside the panel body (1), and a portion of the steel cage (2) extends out of the panel body (1). The permanent prestressed tendons (3) are embedded inside the panel body (1), and the permanent prestressed tendons (3) are arranged along the main force direction of the precast panel; The temporary prestressed tendons (4) are embedded inside the panel body (1), and the temporary prestressed tendons (4) are arranged along the main force direction of the precast panel; both ends of the temporary prestressed tendons (4) extend out of the panel body (1); The prestress release component (5) is installed at the end of the temporary prestressed tendon (4), and the prestress release component (5) is also fixedly connected to the steel cage (2).

2. A precast panel capable of applying prestress to post-cast joints according to claim 1, characterized in that, The thickness of the panel body (1) is 240~400mm, the length is 4000~12000mm, and the width is 1000~4000mm; The panel body (1) is a precast concrete panel, and the panel body (1) is made of concrete with a strength grade of C40 or above.

3. A precast panel capable of applying prestress to post-cast joints according to claim 1, characterized in that, The steel cage (2) is composed of steel bars arranged in an alternating pattern, including transverse steel bars arranged along the length of the panel body (1) and longitudinal steel bars arranged along the width of the panel body (1).

4. A precast panel capable of applying prestress to post-cast joints according to claim 3, characterized in that, In the steel cage (2), the transverse steel bars and the longitudinal steel bars are welded and fixed at the intersection to form an integral frame steel cage (2).

5. A precast panel capable of applying prestress to post-cast joints according to claim 3, characterized in that, In the steel cage (2), the transverse steel bars and the longitudinal steel bars are respectively set as two-layer structures.

6. A precast panel capable of applying prestress to post-cast joints according to claim 5, characterized in that, In the steel cage (2), the steel bars are U-shaped or hook-shaped, and both ends of the steel bars are embedded inside the panel body (1). The corners of the steel bars extend out from the panel body (1).

7. A precast panel capable of applying prestress to post-cast joints according to claim 6, characterized in that, In the steel cage (2), the vertical distance from the farthest end of the steel bar extending out of the panel body (1) to the surface of the panel body (1) is not less than 50 mm.

8. A precast panel capable of applying prestress to post-cast joints according to claim 1, characterized in that, The permanent prestressed tendons (3) and the temporary prestressed tendons (4) are spaced apart and alternately arranged, and the permanent prestressed tendons (3) and the temporary prestressed tendons (4) are arranged axially symmetrically in the panel body (1).

9. A precast panel capable of applying prestress to post-cast joints according to claim 1, characterized in that, The permanent prestressed tendon (3) is a steel strand, steel wire rope or steel bar, and the end of the permanent prestressed tendon (3) is fixed to the panel body (1) by a flat anchor; the temporary prestressed tendon (4) is a steel strand, steel wire rope or steel bar, and one end of the temporary prestressed tendon (4) is fixed to the panel body (1) by a permanent anchor, and the other end of the temporary prestressed tendon (4) is fixed to the panel body (1) by a prestress release component (5); Both the permanent prestressed tendon (3) and the temporary prestressed tendon (4) are located at the center of the precast panel along the thickness direction.

10. A precast panel capable of applying prestress to post-cast joints according to claim 1 or 9, characterized in that, The prestress relief assembly (5) includes a steel frame and tension bolts; The steel frame is embedded in the panel body (1), and the steel frame is welded and fixed to the steel cage (2); The tensioning bolt is threadedly connected to the anchor head at the end of the temporary prestressed tendon (4).

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