Dry connection nodes and connection methods for precast concrete beams

Abstract

This invention provides a dry connection node for precast concrete beams and its connection method, belonging to the field of prefabricated buildings. High-strength bolts are placed above the top surface of the precast concrete beam (within the floor slab height) to increase the connection lever arm of the high-strength bolts. This allows for a connection with the beam reinforcement using a single large-diameter high-strength bolt, achieving a connection of equal strength to the beam reinforcement, greatly improving installation convenience. Shear resistance is provided by a support base, and the clamping of the upper and lower high-strength bolts achieves bidirectional force transmission in both tension and compression (under normal conditions, the upper high-strength bolt resists tension, and the lower high-strength bolt resists compression; this may be reversed during earthquakes), thus addressing the change in bending moment sign of the precast concrete beam under cyclic loads.

Description

Technical Field

[0001] This invention belongs to the field of prefabricated buildings, and in particular relates to a dry connection node for precast concrete beams and its connection method. Background Technology

[0002] In prefabricated concrete structures, the connection nodes between beams and the main building structure (such as columns or shear walls) all need to be cast in place, resulting in the need for scaffolding during beam construction, slow connection speed, and high cost. For example, Chinese patent CN 108049633 A discloses a construction method for precast concrete frame beam-column joints, involving the connection of precast columns and composite beams. Although it achieves a simple and quick on-site connection between precast columns and composite beams, it does not eliminate wet work during beam and column installation and requires steel reinforcement connections, resulting in a large number of connections.

[0003] In recent years, some methods have involved embedding steel sections at the ends of concrete beams and using bolted and welded connections. However, this exposes the steel joints, requiring secondary pouring, resulting in high steel consumption and demanding welding skills from workers. Meanwhile, fully bolted connections require high precision. Therefore, achieving fully bolted connections between beams and columns, especially with a minimal number of bolts for rapid connection, has always been a problem that engineering projects have been eager to solve. Summary of the Invention

[0004] The objective of this invention is to provide a quick-connection node for fully bolted concrete beams. To this end, this invention provides a dry connection node for precast concrete beams, comprising a structural body, precast concrete beams, and an installation assembly. The precast concrete beams are assembled and connected to the structural body via the installation assembly. The installation assembly comprises:

[0005] The first mounting component includes at least an upper embedded sleeve, a lower embedded sleeve, and a support base. The upper and lower embedded sleeves are embedded in the main structure and arranged vertically. The elevation of the upper embedded sleeve is higher than the top surface of the precast concrete beam, and the elevation of the lower embedded sleeve is higher than the bottom surface of the precast concrete beam. The support base is located on the main structure.

[0006] The second mounting component includes at least a second end plate, an upper high-strength bolt, and a lower high-strength bolt. The second end plate is fixed to the end of the precast concrete beam and supported by the support seat. The top of the second end plate extends above the precast concrete beam to form an extension corresponding to the position of the upper embedded sleeve. The upper high-strength bolt and the lower high-strength bolt pass through the second end plate and are correspondingly installed on the upper embedded sleeve and the lower embedded sleeve.

[0007] Preferably, the precast concrete beam is provided with a reinforcing cage, the reinforcing cage including longitudinal bars and stirrups; the second end plate is connected to the longitudinal bars.

[0008] Preferably, a reinforcing brace is formed between the extension section and the precast concrete beam, and the reinforcing brace is connected between the extension section and the longitudinal reinforcement.

[0009] Preferably, the reinforcing brace is a triangular plate; one right-angled side of the triangular plate is connected to the extension section, and the other right-angled side is connected to the longitudinal reinforcement; the reinforcing cage has stirrups at least near the triangular plate.

[0010] Preferably, the number of reinforcing diagonal braces is two, and the upper high-strength bolt is located between the two reinforcing diagonal braces.

[0011] Preferably, there are two supports; the two supports are located on both sides of the second end plate, and the side of the second end plate forms an overlap joint, and the supports are supported on the overlap joint.

[0012] Preferably, the second mounting component further includes a mounting box for mounting the lower high-strength bolt; the mounting box is disposed on the second end plate and embedded in the precast concrete beam, the mounting box has an installation chamber inside, an opening at the bottom corresponding to the bottom of the precast concrete beam, and a side position corresponding to the lower embedded sleeve.

[0013] Preferably, a post-filled adjustment gap is formed between the main structure and the second end plate, and a pressure-bearing adjustment nut is provided on both the upper high-strength bolt and the lower high-strength bolt, with the pressure-bearing adjustment nut located in the post-filled adjustment gap.

[0014] Preferably, the first mounting component further includes a first end plate, which is fixed to the main body of the structure by an embedded part, and the support is disposed on the first end plate;

[0015] The upper pre-embedded sleeve is positioned at the top of the first end plate, and the lower pre-embedded sleeve is positioned at the bottom of the first end plate.

[0016] Preferably, the two precast concrete beams are connected to both sides of a main structure; the upper high-strength bolt and the lower high-strength bolt pass through the main structure and are tensioned to the second end plate of the two precast concrete beams.

[0017] The present invention also provides a connection method for a dry connection node of a precast concrete beam, characterized in that it includes:

[0018] The main structure is formed, and an upper pre-embedded sleeve, a lower pre-embedded sleeve, and a support are embedded and fixed within the main structure; the upper pre-embedded sleeve and the lower pre-embedded sleeve are arranged vertically;

[0019] A precast concrete beam is formed, and a second end plate is fixed at the end of the precast concrete beam. The height of the precast concrete beam is less than the distance between the upper and lower pre-embedded sleeves. The top of the second end plate extends above the precast concrete beam to form an extension section corresponding to the upper pre-embedded sleeve. A through hole is provided on the second end plate for the upper and lower high-strength bolts to pass through.

[0020] In a dry connection, the precast concrete beam is hoisted to the support and supported by the support, and the upper high-strength bolt and the lower high-strength bolt are installed on the upper and lower embedded sleeves respectively.

[0021] Preferably, a floor slab is formed on the precast concrete beam, and the cast-in-place layer of the floor slab at least covers the upper high-strength bolts and extension sections.

[0022] The technical effects of the above-mentioned technical solutions of the present invention arise from one or more of the following combinations:

[0023] The high-strength bolts are positioned above the top surface of the precast concrete beam (within the floor slab height) to increase the connection arm of the high-strength bolts. This allows for a single large-diameter high-strength bolt to achieve a node connection with the reinforcing steel in the beam of equal strength, greatly improving installation convenience. The high-strength bolts used have a strength greater than that of the reinforcing steel, ensuring that the bearing capacity of a single bolt is greater than the sum of the bearing capacities of all the reinforcing steel, enabling single-bolt connections between upper and lower layers of reinforcing steel. Shear resistance is provided by supports, and the clamping of the upper and lower high-strength bolts achieves bidirectional force transmission in both tension and compression (the upper high-strength bolt resists tension under vertical loads, while the lower high-strength bolt resists compression; the opposite may occur under seismic loads), thus addressing the change in bending moment sign of the precast concrete beam under cyclic loads.

[0024] Beam joints are connected by bolts, which allows for fast construction and requires minimal worker skills as welding is not required.

[0025] By utilizing the shear resistance of the reinforcing diagonal braces, the beam can be installed without support. The shear force at the beam end is connected by the reinforcing diagonal braces, and the bolts do not need to bear the shear force. This allows the bolts to have larger holes to adjust for errors, and there is no need to use preload.

[0026] The double-bolted connection on both sides of the end allows the bolt section to resist both compression and tension, thus enabling the beam to withstand the negative bending moment under gravity load and the positive bending moment that may be generated under seismic reciprocating load.

[0027] Traditional bolted connection schemes have poor ability to adjust for errors in the length direction of components. This node uses bolts on both sides of the end plate to adjust for errors caused by inaccurate beam length. The adjustment gap can be filled after adjustment by pressure-adjusting nuts.

[0028] The joint connection does not require on-site casting or post-cast concrete wrapping; it only requires filling the gap after caulking with polymer mortar.

[0029] The nodes require less steel and have a lower cost.

[0030] The exposed high-strength bolts are easy to connect and are embedded in the cast-in-place part of the floor slab after construction is completed. The lower high-strength bolts are set above the bottom of the beam, which also ensures that they are not exposed after construction is completed. Attached Figure Description

[0031] Figure 1 A schematic diagram illustrating the structure of the present invention is shown.

[0032] Figure 2 The front view of the invention is shown.

[0033] Figure 3 This is a schematic diagram illustrating an assembly of the present invention from one perspective.

[0034] Figure 4 This is an assembly diagram illustrating another perspective of the present invention.

[0035] Figure 5 This diagram illustrates the steel structure of the precast concrete beam in this invention.

[0036] Figure 6 This diagram illustrates the steel structure assembly of the structural columns and precast concrete beams in this invention. Detailed Implementation

[0037] The following description is provided to enable those skilled in the art to implement and use the invention and incorporate it into specific application contexts. Various modifications and uses in different applications will be readily apparent to those skilled in the art, and the general principles defined herein are applicable to a wide range of embodiments. Therefore, the invention is not limited to the embodiments given herein, but should be granted the broadest scope consistent with the principles and novel features disclosed herein.

[0038] In the following detailed description, numerous specific details are set forth to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that practice of the invention is not necessarily limited to these specific details. In other words, well-known structures and devices are shown in block diagram form without being depicted in detail to avoid obscuring the invention.

[0039] Readers should note all documents and references submitted concurrently with this specification and open to public inspection, the contents of which are incorporated herein by reference. Unless otherwise expressly stated, all features disclosed in this specification (including any appended claims, abstracts, and drawings) may be replaced by alternative features for the same, equivalent, or similar purposes. Therefore, unless explicitly stated otherwise, each disclosed feature is merely one example of a set of equivalent or similar features.

[0040] Note that, where used, the markings left, right, front, back, top, bottom, front, back, clockwise, and counterclockwise are merely for convenience and do not imply any specific fixed direction. In fact, they are used to reflect the relative position and / or orientation between different parts of an object. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] Note that, in practice, "further," "preferably," "even further," and "more preferably" are simply starting points for describing another embodiment based on the foregoing embodiments. The combination of the content following "further," "preferably," "even further," or "more preferably" with the foregoing embodiments constitutes the complete configuration of another embodiment. Any combination of several "further," "preferably," "even further," or "more preferably" settings following the same embodiment can form yet another embodiment.

[0043] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0044] Structural Example:

[0045] Please refer to Figures 1-6 This invention provides a dry connection node for precast concrete beams, including a structural body, a precast concrete beam 2, and an installation assembly 3. The precast concrete beam 2 is assembled and connected to the structural body via the installation assembly 3. The structural body can be a structural column 1 or a shear wall; this embodiment uses a structural column 1 as the subject for detailed description.

[0046] For specific details, please refer to... Figure 2 , Figure 3 and Figure 4 The installation component 3 includes a first installation component and a second installation component. The first installation component includes at least an upper embedded sleeve 313, a lower embedded sleeve 314, and a support 312. The upper embedded sleeve 313 and the lower embedded sleeve 314 are embedded in the main structure and arranged vertically. The elevation of the upper embedded sleeve 313 is higher than the top surface of the precast concrete beam 2, and the elevation of the lower embedded sleeve 314 is higher than the bottom surface of the precast concrete beam 2. The support 312 is located on the main structure. The second installation component includes at least a second end plate 321 and an upper high-strength... Bolt 322 and lower high-strength bolt 323, second end plate 321 is fixed to the end of precast concrete beam 2, second end plate 321 is supported by support seat 312, the top of second end plate 321 extends above precast concrete beam 2 to form an extension section 3211 corresponding to the position of upper embedded sleeve 313, upper high-strength bolt 322 and lower high-strength bolt 323 pass through second end plate 321 and are correspondingly installed on upper embedded sleeve 313 and lower embedded sleeve 314. In this embodiment, the upper high-strength bolt is placed above the top surface of the precast concrete beam 2 (within the floor slab height) to increase the connection lever arm of the upper high-strength bolt. Thus, a node connection with the same strength as the steel reinforcement in the beam is achieved using a single large-diameter high-strength bolt, greatly improving the ease of installation. Shear resistance is provided by the support seat 312, and the clamping of the upper and lower high-strength bolts achieves bidirectional force transmission in both tension and compression (under normal conditions, the upper high-strength bolt 322 is tensile and the lower high-strength bolt 323 is compressive; the opposite may occur during an earthquake), in order to cope with the change in the bending moment sign of the precast concrete beam 2 under cyclic loads.

[0047] The above solutions constitute the necessity for implementing this embodiment, and will be described in detail below with reference to the accompanying drawings:

[0048] Please combine Figure 3 , Figure 5 and Figure 6 The precast concrete beam 2 is formed in the factory and installed by hoisting on site. Furthermore, the precast concrete beam 2 is equipped with a reinforcing cage, which includes longitudinal bars 21 and stirrups 22. The second installation component is located on the end plate of the precast concrete beam 2. Specifically, the second end plate 321 is connected to the longitudinal bars 21.

[0049] The top of the second end plate 321 extends upward to form an extension section 3211, preferably an extension plate body, considered as part of the second end plate 321. In simpler terms, the second end plate 321 can be considered to be higher than the precast concrete beam 2, and the portion of the top above the precast concrete beam 2 is defined as the extension section 3211, facilitating subsequent structural description. The extension section 3211 serves as the mounting component for the upper high-strength bolt, increasing the connecting lever arm of the upper high-strength bolt. Therefore, installation with the upper embedded sleeve 313 can be achieved using only a single large-diameter high-strength bolt. The height of the extension section 3211 should be lower than the height of the floor slab; ideally, it can be submerged by the cast-in-place floor slab layer, effectively concealing the high-strength bolt at the node.

[0050] Furthermore, reinforcing braces 325 are formed between the precast concrete beams 2. These reinforcing braces 325 connect the extension section 3211 and the longitudinal reinforcement 21 to provide shear resistance. Preferably, the reinforcing brace 325 is a triangular plate; one right-angled side of the triangular plate is connected to the extension section 3211, and the other right-angled side is connected to the longitudinal reinforcement 21. Here, both the extension section 3211 and the triangular plate are steel plates, and the connection method is welding. Furthermore, there are two reinforcing braces 325, and high-strength bolts 322 are located between the two reinforcing braces 325 to provide balanced support, tie, and shear resistance. Preferably, a ring of stirrups 22 should be directly installed at the connection between the triangular plate and the longitudinal reinforcement 21. The bending joint formed by the stirrups 22, the longitudinal reinforcement 21 and the triangular plate prevents the high-strength bolt from pulling the second end plate 321. The second end plate 321 will bend, causing the longitudinal reinforcement 21 to move upward. The stirrups 22 are used to prevent deformation and displacement. Since the high-strength bolt 322 and the longitudinal reinforcement 21 are not on the same axis, the axial force of the longitudinal reinforcement 21 can be reliably transmitted by reinforcing the diagonal brace 325 and the stirrups 22.

[0051] Furthermore, to facilitate the pre-installation of the precast concrete beam 2, in this embodiment, two support seats 312 are used; the two support seats 312 are located on both sides of the second end plate 321 to support and position the second end plate 321. Correspondingly, an overlap joint 3212 is formed on the side of the second end plate 321, and the support seat 312 is supported by the overlap joint 3212. Preferably, the overlap joint 3212 is an L-shaped groove, making the overall second end plate 321 have an inverted convex shape. The support seat 312 is preferably a triangular plate, with one right-angled side welded to the second end plate 321, and the other right-angled side forming a support part.

[0052] As another preferred embodiment of this embodiment, the support 312 can also be a corbel embedded and fixed to the main body of the structure. This embodiment does not limit it to a single embodiment.

[0053] To conceal the high-strength bolts and facilitate installation; please refer to [link / reference needed]. Figure 5 and Figure 6The second mounting component also includes a mounting box 34 for installing the lower high-strength bolt 323. The mounting box 34 is disposed on the second end plate 321 and embedded in the precast concrete beam 2. The mounting box 34 has an installation chamber inside, an opening at the bottom corresponding to the bottom of the precast concrete beam 2, and a side position corresponding to the lower embedded sleeve 314. Preferably, the mounting box 34 is composed of a metal plate with openings at both the side and bottom. The side opening corresponds to the through-hole position of the lower high-strength bolt in the second end plate 321, and the bottom opening corresponds to the bottom surface of the precast concrete beam 2, facilitating installation. This ensures that the bottom of the second end plate 321, the bottom of the precast concrete beam 2, and the bottom opening of the mounting box 34 are at the same elevation, forming a flat structure. On the one hand, it can hide the lower high-strength bolt, which, together with the aforementioned hiding of the upper high-strength bolt, achieves bolt concealment at the joint; on the other hand, it also facilitates subsequent ceiling installation at the bottom.

[0054] Please see Figure 2 In actual installation, there may be a slight error between the beam installation spacing and the actual beam length between the two main structural components. Therefore, a post-filled adjustment gap 33 is formed between the first end plate 311 and the second end plate 321 to eliminate this error. Furthermore, both the upper high-strength bolt 322 and the lower high-strength bolt 323 are equipped with a pressure-bearing adjusting nut 324, which is located in the post-filled adjustment gap 33. On the one hand, the pressure-bearing adjusting nut 324, in conjunction with the nut portion of the high-strength bolt, adjusts the spacing between the second end plate 321 and the main structural component; on the other hand, the clamping of the pressure-bearing adjusting nut 324 between the second end plate 321 and the main structural component also allows the pressure-bearing adjusting nut 324 to bear the pressure, sharing the pull-out resistance of the upper high-strength bolt 322 and the compressive resistance of the lower high-strength bolt 323.

[0055] The first mounting component also includes a first end plate 311, which is fixed to the main structure via an embedded part 315. A support 312 is disposed on the first end plate 311. An upper embedded sleeve 313 is positioned at the top of the first end plate 311, and a lower embedded sleeve 314 is positioned at the bottom of the first end plate 311. Specifically, the embedded part 315 is a pre-embedded reinforcing bar, one end of which is welded to the first end plate 311, and the entire assembly is embedded and fixed within the structural column 1. Furthermore, the top and bottom of the first end plate 311 form grooves adapted to the positioning of the upper embedded sleeve 313 and the lower embedded sleeve 314. The shape of the grooves should fit the outer circumference of the two embedded sleeves to facilitate their positioning during the pouring of the structural column 1. The support 312 is simply welded to the first end plate 311.

[0056] This embodiment can also be implemented with the installation of double-sided beams. Specifically, two precast concrete beams 2 are connected to both sides of the structural column 1. The upper high-strength bolt 322 and the lower high-strength bolt 323 pass through the structural column 1 and are tensioned to the second end plates 321 of the two precast concrete beams 2. In this case, only one upper high-strength bolt 322 and one lower high-strength bolt 323 are needed for the mounting components 3 on both sides. Furthermore, because it is a tension structure, the upper embedded sleeve 313 and the lower embedded sleeve 314 can be omitted.

[0057] The beneficial effects of this embodiment:

[0058] The upper high-strength bolt is set above the top surface of the precast concrete beam 2 (within the floor slab height) to increase the connection lever arm of the upper high-strength bolt. Thus, a node connection with the same strength as the steel reinforcement in the beam is achieved by using a single large-diameter high-strength bolt, which greatly improves the ease of installation. Shear resistance is provided by support seat 312. Combined with the clamping of the upper and lower high-strength bolts, bidirectional force transmission of tension and compression is achieved (under normal conditions, the upper high-strength bolt 322 is for tension and the lower high-strength bolt 323 is for compression; the opposite may be true during an earthquake) to cope with the change in the bending moment sign of the precast concrete beam 2 under cyclic loads.

[0059] Beam joints are connected by bolts, which allows for fast construction and requires minimal worker skills as welding is not required.

[0060] By utilizing the shear resistance of the reinforcing diagonal brace 325, the beam can be installed without support. The shear force at the beam end is connected by the reinforcing diagonal brace 325, and the bolts do not need to bear the shear force. This allows the bolts to have larger holes to adjust for errors, and there is no need to use preload.

[0061] The double-bolted connection on both sides of the end allows the bolt section to resist both compression and tension, thus enabling the beam to withstand the negative bending moment under gravity load and the positive bending moment that may be generated under seismic reciprocating load.

[0062] Traditional bolted connection schemes have poor ability to adjust for errors in the length direction of components. This node uses bolts on both sides of the end plate to adjust for errors caused by inaccurate beam length. The adjustment gap 33 can be filled after adjustment by the pressure adjusting nut 324.

[0063] The node connection does not require in-situ casting or post-cast concrete wrapping; it only requires filling the gap 33 after caulking with polymer mortar.

[0064] The nodes require less steel and have a lower cost.

[0065] Method Implementation Examples:

[0066] Please refer to Figures 1-6 This embodiment provides a connection method for a dry connection node of a precast concrete beam, including the following steps:

[0067] S1: Main structural form:

[0068] Specifically, an upper embedded sleeve 313, a lower embedded sleeve 314, and a support 312 are embedded and fixed within the main structure; the upper embedded sleeve 313 and the lower embedded sleeve 314 are arranged vertically. The main structure can be a structural column 1 or a shear wall; this embodiment uses the structural column 1 as the object for detailed description. During the casting of the structural column 1, the upper embedded sleeve, the lower embedded sleeve, and the support are arranged within the casting mold and integrally formed with the structural column 1.

[0069] Furthermore, to facilitate the pre-installation of the precast concrete beam 2, in this embodiment, the number of support seats 312 is two. As another preferred embodiment, the support seats 312 can also be corbels embedded and fixed to the main structure; this embodiment does not impose a limitation on this.

[0070] The main structure also includes a first end plate 311, which is fixed to the main structure via an embedded part 315. A support 312 is mounted on the first end plate 311. An upper embedded sleeve 313 is positioned at the top of the first end plate 311, and a lower embedded sleeve 314 is positioned at the bottom of the first end plate 311. Specifically, the embedded part 315 is a pre-embedded reinforcing bar, one end of which is welded to the first end plate 311, and the entire assembly is embedded and fixed within the structural column 1. Furthermore, the top and bottom of the first end plate 311 have grooves adapted to the positioning of the upper embedded sleeve 313 and the lower embedded sleeve 314. The shape of the grooves should fit the outer circumference of the two embedded sleeves to facilitate their positioning during the pouring of the structural column 1. The support 312 is simply welded to the first end plate 311.

[0071] S2: Precast concrete beam forming:

[0072] Specifically, a second end plate 321 is fixed at the end of the precast concrete beam 2. The height of the precast concrete beam 2 is less than the distance between the upper embedded sleeve 313 and the lower embedded sleeve 314. The top of the second end plate 321 extends above the precast concrete beam 2 to form an extension section 3211 corresponding to the position of the upper embedded sleeve 313. Through holes are provided on the second end plate 321 for the upper high-strength bolt 322 and the lower high-strength bolt 323 to pass through.

[0073] If the height of the precast concrete beam 2 is less than the distance between the upper embedded sleeve 313 and the lower embedded sleeve 314, it can be implemented such that the elevation of the upper embedded sleeve 313 is higher than the top surface of the precast concrete beam 2, and the elevation of the lower embedded sleeve 314 is higher than the bottom surface of the precast concrete beam 2.

[0074] Support 312 is provided on the main structure; second end plate 321 is fixed to the end of precast concrete beam 2, second end plate 321 is supported by support 312, the top of second end plate 321 extends above precast concrete beam 2 to form an extension 3211 corresponding to the position of upper embedded sleeve 313, upper high-strength bolt 322 and lower high-strength bolt 323 pass through the through hole of second end plate 321 and are installed in the upper embedded sleeve 313 and lower embedded sleeve 314 respectively.

[0075] The precast concrete beam 2 is formed in the factory and installed by hoisting on site. Furthermore, the precast concrete beam 2 contains a reinforcing cage, which includes longitudinal bars 21 and stirrups 22. A second end plate 321 is connected to the longitudinal bars 21. If both ends of the precast concrete beam 2 are installed through the nodes of this embodiment, both ends of the precast concrete beam 2 are provided with second end plates 321. The distance between the two end plates is the length of the beam. The longitudinal bars 21 are welded to the second end plates 321 to form a reinforcing cage, which is then cast in a mold.

[0076] The top of the second end plate 321 extends upward to form an extension section 3211, preferably an extension plate body, considered as part of the second end plate 321. In simpler terms, the second end plate 321 can be considered to be higher than the precast concrete beam 2, and the portion of the top above the precast concrete beam 2 is defined as the extension section 3211, facilitating subsequent structural description. The extension section 3211 serves as the mounting component for the upper high-strength bolt, increasing the connecting lever arm of the upper high-strength bolt. Therefore, installation with the upper embedded sleeve 313 can be achieved using only a single large-diameter high-strength bolt. The height of the extension section 3211 should be lower than the height of the floor slab; ideally, it can be submerged by the cast-in-place floor slab layer, effectively concealing the high-strength bolt at the node.

[0077] Furthermore, reinforcing braces 325 are formed between the precast concrete beams 2. These reinforcing braces 325 connect the extension section 3211 and the longitudinal reinforcement 21 to provide shear resistance. Preferably, the reinforcing brace 325 is a triangular plate; one right-angled side of the triangular plate is connected to the extension section 3211, and the other right-angled side is connected to the longitudinal reinforcement 21. Here, both the extension section 3211 and the triangular plate are steel plates, and the connection method is welding. Furthermore, there are two reinforcing braces 325, and high-strength bolts 322 are located between the two reinforcing braces 325 to provide balanced support, tie, and shear resistance. Preferably, a ring of stirrups 22 should be directly installed at the connection between the triangular plate and the longitudinal reinforcement 21. The bending joint formed by the stirrups 22, the longitudinal reinforcement 21, and the triangular plate prevents the high-strength bolt from pulling on the second end plate 321. The second end plate 321 will bend, causing the longitudinal reinforcement 21 to be pulled upwards. The stirrups 22 prevent deformation and displacement. Since the high-strength bolt 322 and the longitudinal reinforcement 21 are not on the same axis, the axial force of the longitudinal reinforcement 21 can be reliably transmitted by reinforcing diagonal braces 325 and stirrups 22. Preferably, during the pouring of the precast concrete beam 2, the longitudinal reinforcement 21 is welded to the second end plate 321 to form a reinforcing cage, and the triangular plate is also welded to the longitudinal reinforcement 21 for the pouring of the precast concrete beam 2.

[0078] Two supports 312 are located on both sides of the second end plate 321 to support and position the second end plate 321. Correspondingly, the side of the second end plate 321 has an overlap joint 3212, on which the supports 312 are supported. Preferably, the overlap joint 3212 is an L-shaped groove, making the overall second end plate 321 have an inverted convex shape. The supports 312 are preferably triangular plates, with one right-angled side welded to the second end plate 321, and the other right-angled side forming a support portion.

[0079] To conceal the high-strength bolts and facilitate installation; please refer to [link / reference needed]. Figure 5 and Figure 6 The precast concrete beam 2 also includes an installation box 34 for installing the lower high-strength bolts 323. The installation box 34 is located on the second end plate 321 and embedded in the precast concrete beam 2. The installation box 34 has an installation chamber inside, an opening at the bottom corresponding to the bottom of the precast concrete beam 2, and a side position corresponding to the lower embedded sleeve 314. Preferably, the installation box 34 is made of metal plate with openings at the side and bottom. The side opening corresponds to the through hole position of the lower high-strength bolt in the second end plate 321, and the bottom opening corresponds to the bottom surface of the precast concrete beam 2, facilitating installation. This ensures that the bottom of the second end plate 321, the bottom of the precast concrete beam 2, and the bottom opening of the installation box 34 are at the same elevation, forming a flat structure. On the one hand, it can hide the lower high-strength bolts, which, together with the aforementioned hiding of the upper high-strength bolts, achieves bolt hiding at the joint; on the other hand, it also facilitates subsequent installation of the bottom ceiling, etc.

[0080] S3: Dry connection:

[0081] Specifically, the precast concrete beam 2 is hoisted to the support 312 and supported by the support 312, and the upper high-strength bolt 322 and the lower high-strength bolt 323 are installed on the upper embedded sleeve 313 and the lower embedded sleeve 314 respectively.

[0082] Please see Figure 2 In actual installation, there may be a slight error between the beam installation spacing and the actual beam length between the two main structural components. Therefore, a post-filled adjustment gap 33 is formed between the first end plate 311 and the second end plate 321 to eliminate this error. Furthermore, both the upper high-strength bolt 322 and the lower high-strength bolt 323 are equipped with a pressure-bearing adjusting nut 324, which is located in the post-filled adjustment gap 33. On the one hand, the pressure-bearing adjusting nut 324, in conjunction with the nut portion of the high-strength bolt, adjusts the spacing between the second end plate 321 and the main structural component; on the other hand, the clamping of the pressure-bearing adjusting nut 324 between the second end plate 321 and the main structural component also allows the pressure-bearing adjusting nut 324 to bear the pressure, sharing the pull-out resistance of the upper high-strength bolt 322 and the compressive resistance of the lower high-strength bolt 323.

[0083] Finally, the post-cast floor slab is formed.

[0084] The floor slab (not shown) is formed on the precast concrete beam 2. The cast-in-place layer of the floor slab can be at least covered by the high-strength bolts and extension sections to complete the design of the upper part of the installation components.

[0085] The beneficial effects of this embodiment:

[0086] The upper high-strength bolt is set above the top surface of the precast concrete beam 2 (within the floor slab height) to increase the connection lever arm of the upper high-strength bolt. Thus, a node connection with the same strength as the steel reinforcement in the beam is achieved by using a single large-diameter high-strength bolt, which greatly improves the ease of installation. Shear resistance is provided by support seat 312. Combined with the clamping of the upper and lower high-strength bolts, bidirectional force transmission of tension and compression is achieved (under normal conditions, the upper high-strength bolt 322 is for tension and the lower high-strength bolt 323 is for compression; the opposite may be true during an earthquake) to cope with the change in the bending moment sign of the precast concrete beam 2 under cyclic loads.

[0087] Beam joints are connected by bolts, which allows for fast construction and requires minimal worker skills as welding is not required.

[0088] By utilizing the shear resistance of the reinforcing diagonal brace 325, the beam can be installed without support. The shear force at the beam end is connected by the reinforcing diagonal brace 325, and the bolts do not need to bear the shear force. This allows the bolts to have larger holes to adjust for errors, and there is no need to use preload.

[0089] The double-bolted connection on both sides of the end allows the bolt section to resist both compression and tension, thus enabling the beam to withstand the negative bending moment under gravity load and the positive bending moment that may be generated under seismic reciprocating load.

[0090] Traditional bolted connection schemes have poor ability to adjust for errors in the length direction of components. This node uses bolts on both sides of the end plate to adjust for errors caused by inaccurate beam length. The adjustment gap 33 can be filled after adjustment by the pressure adjusting nut 324.

[0091] The node connection does not require in-situ casting or post-cast concrete wrapping; it only requires filling the gap 33 after caulking with polymer mortar.

[0092] The nodes require less steel and have a lower cost.

[0093] Furthermore, the present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A dry connection node for precast concrete beams, comprising a structural body, precast concrete beams, and installation components, wherein the precast concrete beams are assembled and connected to the structural body via the installation components; characterized in that, The installation components include: The first mounting component includes at least an upper embedded sleeve, a lower embedded sleeve, and a support base. The upper and lower embedded sleeves are embedded in the main structure and arranged vertically. The elevation of the upper embedded sleeve is higher than the top surface of the precast concrete beam, and the elevation of the lower embedded sleeve is higher than the bottom surface of the precast concrete beam. The support base is located on the main structure. The second mounting component includes at least a second end plate, an upper high-strength bolt, and a lower high-strength bolt. The second end plate is fixed to the end of the precast concrete beam and supported by the support seat. The top of the second end plate extends above the precast concrete beam to form an extension corresponding to the position of the upper embedded sleeve. The upper high-strength bolt and the lower high-strength bolt pass through the second end plate and are correspondingly installed on the upper embedded sleeve and the lower embedded sleeve.

2. The dry connection node for precast concrete beams as described in claim 1, characterized in that: The precast concrete beam is equipped with a steel cage, which includes longitudinal bars and stirrups; the second end plate is connected to the longitudinal bars.

3. The dry connection node for precast concrete beams as described in claim 2, characterized in that: A reinforcing brace is formed between the extension section and the precast concrete beam, and the reinforcing brace is connected between the extension section and the longitudinal reinforcement.

4. The dry connection node for precast concrete beams as described in claim 3, characterized in that: The reinforcing brace is a triangular plate; one right-angled side of the triangular plate is connected to the extension section, and the other right-angled side is connected to the longitudinal reinforcement; the steel cage has stirrups at least near the triangular plate.

5. The dry connection node for precast concrete beams as described in claim 4, characterized in that: The number of the reinforcing diagonal braces is two, and the upper high-strength bolt is located between the two reinforcing diagonal braces.

6. The dry connection node for precast concrete beams as described in claim 1, characterized in that: The number of the support seats is two; the two support seats are located on both sides of the second end plate, and the side of the second end plate forms an overlap interface, and the support seats are supported on the overlap interface.

7. The dry connection node for precast concrete beams as described in claim 1, characterized in that: The second mounting component also includes a mounting box for mounting the lower high-strength bolt; the mounting box is disposed on the second end plate and embedded in the precast concrete beam, the mounting box has an installation chamber inside, an opening at the bottom corresponding to the bottom of the precast concrete beam, and the side position corresponds to the lower embedded sleeve.

8. The dry connection node for precast concrete beams as described in claim 1, characterized in that: A post-filled adjustment gap is formed between the main structure and the second end plate. Both the upper high-strength bolt and the lower high-strength bolt are provided with pressure-bearing adjustment nuts, which are located in the post-filled adjustment gap.

9. The dry connection node for precast concrete beams as described in claim 1, characterized in that: The first mounting component also includes a first end plate, which is fixed to the main body of the structure by an embedded part, and the support is disposed on the first end plate; The upper pre-embedded sleeve is positioned at the top of the first end plate, and the lower pre-embedded sleeve is positioned at the bottom of the first end plate.

10. The connection method for dry connection nodes of precast concrete beams as described in any one of claims 1 to 9, characterized in that, include: The main structure is formed, and an upper pre-embedded sleeve, a lower pre-embedded sleeve, and a support are embedded and fixed within the main structure; the upper pre-embedded sleeve and the lower pre-embedded sleeve are arranged vertically; A precast concrete beam is formed, and a second end plate is fixed at the end of the precast concrete beam. The height of the precast concrete beam is less than the distance between the upper and lower pre-embedded sleeves. The top of the second end plate extends above the precast concrete beam to form an extension section corresponding to the upper pre-embedded sleeve. A through hole is provided on the second end plate for the upper and lower high-strength bolts to pass through. In a dry connection, the precast concrete beam is hoisted to the support and supported by the support, and the upper high-strength bolt and the lower high-strength bolt are installed on the upper and lower embedded sleeves respectively.

11. The connection method as described in claim 10, characterized in that, A floor slab is formed on the precast concrete beam, and the cast-in-place layer of the floor slab at least covers the upper high-strength bolts and the extension section.

Images