Modular concrete building structure connection node and construction method thereof

Abstract

The present application relates to the technical fields of prefabricated building, and especially relates to a modular concrete building structure connecting joint and a construction method thereof, which comprises a base module, at least one upper module, a vertical connecting assembly and a horizontal connecting assembly, the base module comprises a base layer and a first layer module structure column arranged on the base layer, the upper module comprises an upper module structure column arranged above the first layer module structure column, the vertical connecting assembly comprises a reserved anchor rod pre-buried in adjacent module structure columns, a metal bellows sleeved at the connecting position of the reserved anchor rod and grouting material filled in the metal bellows, and is used for realizing vertical stress connection between the modules. The present application effectively solves the problems of poor integrity and insufficient anti-seismic performance of the existing box type modular building connecting joint, and significantly enhances the structural integrity, stability and construction efficiency through the innovative design of vertical and horizontal collaborative connection.

Description

Technical Field

[0001] This invention relates to the field of prefabricated building technology, and in particular to a modular concrete building structure connection node and its construction method. Background Technology

[0002] Modular building is a highly integrated prefabricated building system that prefabricates fully functional three-dimensional spatial modules (or 'box modules') in a factory and then transports them to the site for rapid assembly. This construction method has significant advantages in improving construction efficiency, ensuring project quality, and achieving green building. Concrete modules, due to their excellent durability, fire resistance, and load-bearing capacity, have broad application prospects in low- and mid-rise residential buildings, apartments, hotels, and other fields.

[0003] The core technology of modular construction lies in the connection nodes between modules. These connection nodes must reliably transmit vertical loads and horizontal forces (such as seismic forces) to ensure sufficient structural integrity and seismic resistance, preventing progressive collapse. Simultaneously, the node design should facilitate rapid on-site installation to leverage the efficient construction advantages of modular buildings.

[0004] Currently, connection technologies for modular concrete buildings are mainly divided into two categories: dry connections and wet connections. Dry connections mostly use mechanical methods such as bolts and welding, which are quick to construct, but the joint stiffness and overall integrity are usually not as good as cast-in-place structures. Wet connections, on the other hand, connect the components into a whole by pre-reserving steel bars, sleeves, or channels in precast components and then pouring concrete or grouting material on site. Its integrity is closer to that of cast-in-place structures, and it is more widely used.

[0005] In wet connection methods, grouting sleeves and corrugated metal pipe grout anchors are two mainstream technologies. For example, existing technologies (such as patent CN120844723A) disclose a "connection node for a fully precast concrete modular shear wall system," which achieves vertical connection between upper and lower modules by pre-embedding corrugated metal pipes in the edge members of the fully precast shear wall modules and then pouring concrete inside the pipes. Simultaneously, a post-cast area is set between the shear wall module and the fully precast integrated beam slab, and horizontal connection is achieved by lapping reinforcing bars and pouring concrete within the groove. This technology optimizes the node structure of the shear wall system, aiming to solve problems such as the difficulty of sleeve grouting operations and the large amount of in-situ casting required by traditional post-casting methods, thereby improving assembly efficiency.

[0006] However, the aforementioned existing technologies primarily optimize shear wall structural systems composed of components such as walls, beams, and slabs. For the increasingly popular "box-type modular concrete structures" that utilize entire rooms as units, the connection requirements differ significantly. A box-type module is a hexagonal closed "box," and its connections must simultaneously address the vertical connection between the top and bottom modules, the lateral connection of the side walls of adjacent modules, and the horizontal continuity of the floor slab, resulting in a more complex construction. Directly applying connection solutions designed for shear wall systems may face the following challenges:

[0007] Adaptability of force transmission path: The connection of shear wall system mainly focuses on the continuity of the wall itself and the reliability of the wall-beam joint. However, the corners and edges of the box module are the key parts of the force, which require an overall connection scheme that can effectively transmit internal forces in all directions and ensure the coordinated work between modules.

[0008] Targeted construction and installation: The existing technology for post-cast area design of nodes may not be able to perfectly adapt to the joint structure formed when splicing the sides of box modules, making it difficult to achieve efficient and flat connection of the box side floor slabs while ensuring connection strength.

[0009] Specialization of seismic performance: Low-rise and multi-story box-type houses have clear requirements for structural integrity and seismic ductility, requiring connection nodes to have excellent energy dissipation capacity and robustness to prevent progressive collapse, which may not be the focus of optimization in general solutions for non-box-type systems.

[0010] Therefore, developing a connection node and construction method specifically designed for the characteristics of box-type modular concrete structures, capable of achieving reliable vertical and horizontal connections, ensuring structural integrity and seismic performance, and facilitating construction, is of significant engineering importance and market demand. Summary of the Invention

[0011] The purpose of this invention is to provide a modular concrete building structure connection node and its construction method to solve the problems mentioned in the background art, such as insufficient seismic performance of current prefabricated low-rise and multi-story box-type concrete structure houses, inability to guarantee the continuity of components and the overall stability of the structure, and inability to ensure that the structure has the necessary load-bearing capacity, rigidity and ductility, as well as good wind resistance, earthquake resistance and accidental load resistance. The structural system may collapse continuously at any time, and the safety cannot be guaranteed.

[0012] To achieve the above objectives, the present invention provides the following technical solution: a modular concrete building structure connection node, comprising a foundation module, at least one upper module, a vertical connection component, and a horizontal connection component;

[0013] The basic module includes a basic layer and a first-layer module structure column disposed thereon;

[0014] The upper module includes an upper module structure column disposed above the first-layer module structure column;

[0015] The vertical connection assembly includes pre-embedded anchor bars in the structural columns of adjacent modules, a corrugated metal pipe sleeved at the connection of the pre-embedded anchor bars, and grouting material filled in the corrugated metal pipe, which is used to realize the vertical force connection between modules.

[0016] The horizontal connection component includes a tight joint formed between adjacent module structural columns and floor slabs, a post-cast groove opened at the tight joint, and post-cast concrete filled in the post-cast groove, for realizing horizontal force connection between modules.

[0017] Preferably, mortar is laid between the base layer and the first-layer module structure column, and between the first-layer module structure column and the upper module structure column.

[0018] Preferably, the side wall of the metal corrugated pipe is provided with a grouting port.

[0019] Preferably, at least three of the metal corrugated pipes are arranged at intervals along the length direction on each side of the cross-section of the first-layer module structure column and the upper module structure column.

[0020] Preferably, four sets of reserved anchor bars are provided inside the metal corrugated pipe located at the corner of the modular structure column, and four sets of grouted lapped post-reinforcement bars are provided on its outer side.

[0021] Preferably, two sets of reserved anchor bars are provided inside the metal corrugated pipe located at the end of the column of the modular structure, and two sets of grout-anchored post-installed steel bars are provided on its outer side.

[0022] Preferably, the post-cast trench is provided with a transverse connecting steel reinforcement assembly, which includes additional tie bars and connecting stirrups.

[0023] Preferably, the post-cast strip formed at the joint has a width of 75mm and a depth of 120mm.

[0024] A construction method for connection nodes in a modular concrete building structure includes the following steps:

[0025] S1. Vertical connection construction: After laying the grout on the foundation layer, hoist the first-floor module structural column into place, aligning the pre-embedded anchor bars of the first-floor module with the pre-embedded anchor bars of the foundation layer; install metal corrugated pipes at the joints, and inject grout through the grouting port until it is filled and cured, thus completing the first-floor installation.

[0026] S2. Repeated vertical connection construction: Lay grout on the top of the installed module, hoist the upper module structural column into place, align the pre-embedded upper module anchor bars with the pre-embedded lower module anchor bars, and repeat the grouting connection process to complete the installation of the upper module.

[0027] S3. Horizontal connection construction: At the close joint of the floor slab of the adjacent module structural column, clean the post-pouring groove and arrange the horizontal connecting steel reinforcement components. Then, set up the formwork and pour post-pouring concrete into the post-pouring groove. After it has cured, a horizontal connection node is formed.

[0028] Preferably, in steps S1 and S2, pressure grouting is used when injecting grout into the metal corrugated pipe, and the injection is continued until the grout overflows from the top of the metal corrugated pipe.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] 1. This invention forms a three-dimensional rigid connection system by using vertical and horizontal connection components. In the vertical connection, the high-performance grout inside the metal corrugated pipe provides high-bond-strength anchorage for the pre-reserved anchor bars and the post-installed reinforcing bars after the grout-anchor lap joint, ensuring reliable transmission of vertical loads and the pull-out resistance of the joints. In the horizontal connection, the post-cast trench and its internal additional tie bars, connecting stirrups, and post-cast concrete work together to firmly connect the floor slabs of adjacent modules into a whole, effectively transmitting horizontal shear force and bending moment. The two work together to enable the independent box-type modules to work collaboratively like cast-in-place structures, greatly enhancing the integrity, stability, and lateral stiffness of the building.

[0031] 2. The construction method of this invention has clear steps and strong standardization. Vertical connections are made using on-site pressure grouting, and the density can be intuitively judged by observing the overflow of grout at the grouting port, making quality easy to control. The post-cast strips for horizontal connections have optimized specific dimensions, which minimizes the amount of concrete used in on-site wet work and the amount of formwork support work while ensuring connection strength. The laying of the grouting material effectively ensures the initial leveling and contact compaction during module hoisting. The entire process significantly improves construction efficiency, reduces the complexity of on-site operations and reliance on skilled workers, and strongly supports the advantages of efficient and high-quality modular building construction.

[0032] 3. This invention specifically optimizes the structure for the stress characteristics of "modular box-type concrete structures". For example, four sets of reinforcing bars are set in the critical stress areas at the corners of the modules, and two sets of reinforcing bars are set at the edges, achieving an optimized match between stress and materials. The design of opening grouting ports on the sidewalls of the corrugated metal pipes facilitates on-site construction operations. The connection node has a clear structure and a direct stress path, making it particularly suitable for low-rise and multi-story box-type residential buildings, apartments, and other building systems. It solves the problem of dedicated connections in critical parts such as corners and edges of such structures, and has broad applicability and promotional value.

[0033] 4. While pursuing structural safety and seismic performance, the invention achieves good comprehensive economic benefits through structural optimization and construction technology improvement. The reliability of its connection reduces the maintenance risks and costs throughout the structure's life cycle, while the improvement of construction efficiency and optimization of material usage directly save construction costs and time. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the grout-anchored lap connection structure between the first-layer module and the foundation of the present invention;

[0035] Figure 2 This is a schematic diagram of the mortar anchor lap connection structure of the upper and lower modules of the present invention;

[0036] Figure 3 This is a schematic diagram of the cross-sectional view of the upper module structure column of the present invention;

[0037] Figure 4 This is a schematic diagram of the horizontal connection structure of the module of the present invention.

[0038] In the diagram: 1. Foundation layer; 2. First-floor module structural column; 3. Grouting material; 4. Corrugated metal pipe; 5. Foundation anchor bar; 6. First-floor module anchor bar; 7. Grouting material; 8. Grouting port; 9. Upper module structural column; 10. Lower module anchor bar; 11. Upper module anchor bar; 12. Post-installed reinforcement bar after grouting and anchoring; 13. Tight joint; 14. Post-cast trench; 15. Additional tie bar; 16. Connecting stirrup; 17. Longitudinal reinforcement of connecting beam; 18. Longitudinal reinforcement of slab. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Please see Figure 1-4This invention provides a technical solution: a modular concrete building structure connection node, including a foundation module, at least one upper-level module, vertical connection components, and horizontal connection components. The foundation module is the starting and load-bearing foundation of the building structure. Its foundation layer 1 is usually a cast-in-place reinforced concrete strip foundation, raft foundation, or pile foundation. During construction, its top surface elevation and flatness must be strictly controlled, with the error controlled within ±3mm. It also has pre-embedded foundation anchor bars 5. The first-level module structural column 2 set on it is the core vertical load-bearing component of the factory-prefabricated box-type concrete module. It is usually located at the four corners of the module or at the junction of partition walls. The column is integrally cast with the module's wall panels and floor slabs, and is equipped with longitudinal load-bearing steel bars and stirrups determined by structural calculations. The upper module is used to construct the structure of the second floor and above. Its upper module structural column 9 is consistent with the first-floor module structural column 2 in terms of construction form, reinforcement principle and connection interface design. Through layer-by-layer hoisting, alignment and connection, the vertical superposition and load transfer of the building are realized. The vertical connection component is the core structure to ensure the reliable transfer of axial force, bending moment and shear force between the upper and lower modules. Its core lies in the fact that during the factory prefabrication, metal corrugated pipes 4 are pre-embedded at designated positions (such as corners and edges) at the top of the module structural columns 2 and 9, and the lower module reserved anchor bars 10 and the upper module reserved anchor bars 11 are reserved with a certain length of extension. During on-site installation, the pre-reserved anchor bars 10 extending from the top of the lower module and the pre-reserved anchor bars 11 at the bottom of the upper module are connected by one or more mortar-grouted lapped reinforcing bars 12. Then, a corrugated metal pipe 4 is installed over the connection area. Finally, a high-strength, high-flowability, micro-expansion special cement-based grout 7 is injected into the pipe through the grouting port 8. After the grout 7 cures, it generates strong adhesion and mechanical interlocking force with the reinforcing bars and the inner wall of the corrugated pipe, thus forming a vertical connection node with excellent rigidity and integrity. The horizontal connection components ensure the coordinated work and formation between adjacent box-type modules on the same floor. The key to forming a complete floor system is that, during factory production, regular, tight-fitting joints 13 are pre-formed on all sides of each box-type modular floor slab, and a groove-shaped post-pouring groove 14 is reserved in the middle of the joint surface. After hoisting and positioning on site, the tight-fitting joints 13 of the adjacent modules are naturally aligned, and the reinforcement is arranged and connected within the space of the formed post-pouring groove 14. Finally, fine stone concrete with shrinkage compensation function is poured. After it cures, the post-pouring concrete and the precast floor slab concrete are combined into a whole, so that the originally independent floor slabs are connected into a complete horizontal force system, which jointly bears the vertical load and transmits the horizontal force.

[0041] Furthermore, grout 3 is laid between the foundation layer 1 and the first-floor module structural column 2, and between the first-floor module structural column 2 and the upper module structural column 9. This grout 3 is a dry-hard cement-based mortar with early strength, high strength, high adhesion and low shrinkage characteristics. Its strength grade is not lower than that of the module concrete itself, usually M40 or higher grade. During construction, after cleaning and moistening the top surface of the lower component (foundation layer 1 or the installed module), the grout 3 mixed evenly according to the ratio is laid in the predetermined position. The laying thickness should be controlled between 20mm and 30mm. A screed is used to level it to control the elevation and flatness. Its main functions are threefold: First, it serves as a leveling layer to compensate for dimensional errors between factory prefabrication and on-site installation, ensuring the initial horizontality and verticality of the upper module during installation; second, it enables the vertical pressure transmitted from the upper module to be evenly and effectively diffused to the lower structure; and third, it seals the bottom of the horizontal joint between the upper and lower modules, providing a base layer for possible subsequent waterproofing treatment and preventing leakage when grouting material is injected into the vertical connection node.

[0042] Furthermore, the side wall of the metal corrugated pipe 4 is provided with a grouting port 8. This grouting port 8 is usually a metal pipe joint with a standard internal thread, which is firmly welded or tied to the side wall of the metal corrugated pipe 4 during factory prefabrication, with its center position about 100mm to 150mm from the bottom of the corrugated pipe. This design shifts the grouting operation surface from the top of the component to the side, making it easier for on-site workers to quickly connect the grouting hose in situations with limited operating space. During the grouting operation, the grouting material 7 is injected from the grouting port 8 at the bottom under pressure, filling the entire cavity inside the metal corrugated pipe 4 from bottom to top. This effectively removes air from the cavity, ensuring a dense and void-free grouting. When the grouting material 7 flows continuously and evenly from the pre-set outlet at the top of the metal corrugated pipe 4, and the grout concentration is consistent with that at the inlet, it can be determined that the grouting is complete. Then, the outlet is sealed and pressure is maintained for a short time.

[0043] Furthermore, at least three corrugated metal pipes 4 are spaced along the length of each side of the cross-section of the first-floor modular column 2 and the upper modular column 9. This arrangement is a standardized design based on the typical cross-sectional dimensions of the box-type modular column (side length is usually not less than 600mm) and the structural stress requirements. By setting no less than three corrugated metal pipes 4 on each side of the column cross-section, multiple uniformly distributed vertical force transmission paths can be formed along the column. This not only significantly improves the overall bearing capacity and bending stiffness of the joint, but also provides good stress redundancy. When there is a minor defect in a certain connection, the load can be effectively redistributed through other paths. This arrangement also enables the joint to better adapt to the complex stress conditions of compression, bending, and shear that may occur in the column under wind loads or seismic action. The specific center-to-center spacing of the corrugated metal pipes 4 should be determined according to the structural design calculations, usually controlled between 200mm and 300mm, and kept uniform.

[0044] Furthermore, four sets of reserved anchor bars are installed inside the metal corrugated pipe 4 located at the corner of the modular structure column, and four sets of grouted lapped reinforcing bars 12 are installed on the outside of it. The corner of the box module is the most complex and critical part of the structure, bearing bending moment, shear force and large axial pressure from two directions. Therefore, a dense reinforcement scheme of "four inside and four outside" is adopted in each metal corrugated pipe 4 connection node at the corner. Among them, the four sets of reserved anchor bars (such as the reserved anchor bars 10 in the lower module or the reserved anchor bars 11 in the upper module) embedded in the modular concrete are reliably connected to the main reinforcement of the modular column, forming a rigid core inside the node; the four sets of grout-anchored lapped reinforcing bars 12 set on the outside are used to connect with the corresponding reserved anchor bars in the lower layer, forming a force transmission medium between nodes. These eight reinforcing bars together form a strong three-dimensional reinforcing cage at the corner, which is wrapped by grouting material 7 and constrained by metal corrugated pipe 4, thereby greatly enhancing the compression, shear, pull and torsion resistance of the corner node. It is a key design to ensure the overall spatial rigidity of the modular building and prevent stress concentration and damage.

[0045] Furthermore, within the corrugated metal pipe 4 located at the end of the modular structural column, two sets of pre-reserved anchor bars are correspondingly installed, and two sets of grouted lapped reinforcing bars 12 are correspondingly installed on their outer sides. At the non-corner end of the structural column, the stress state is relatively simple compared to the corner, mainly manifested as axial pressure and unidirectional bending moment around the weak axis. Therefore, a "two inner and two outer" reinforcement configuration is adopted here. The two sets of pre-reserved anchor bars embedded in the module and the two sets of grouted lapped reinforcing bars 12 used for connection on the outside work together to effectively transfer the internal forces borne at this location. This differentiated reinforcement design reflects a refined and economical design concept, effectively optimizing the amount of reinforcing bars and reducing material costs while meeting structural requirements, under the premise of ensuring structural safety and reliability.

[0046] Furthermore, the post-cast trench 14 is provided with a transverse connecting steel reinforcement assembly, which includes additional tie bars 15 and connecting stirrups 16. The additional tie bars 15 are usually made of HRB400 grade or higher ribbed steel bars, and their diameter is determined by calculation, generally not less than 10mm. It is arranged along the length of the post-cast groove 14. If the length is insufficient, it can be extended by mechanical sleeve connection or welding. The two ends of the additional tie bar 15 need to be reliably connected to the pre-extended longitudinal reinforcement 18 or the pre-embedded sleeve in the adjacent module floor slab (such as using straight thread sleeve or welding). Its core function is to bear the tensile force generated at the joint of the floor slab under horizontal load (such as seismic force) to ensure the continuity of the floor slab. The connecting stirrup 16 is usually a closed stirrup or a U-shaped open stirrup made of HPB300 or HRB400 grade plain round or ribbed steel bars. Its spacing is generally 100mm to 200mm. The connecting stirrup 16 is arranged perpendicular to the additional tie bar 15 and wrapped inside it. Its main functions are threefold: first, to restrain the post-cast concrete in the post-cast groove 14 and improve its crack resistance and deformation capacity; second, to form a steel skeleton together with the additional tie bar 15 to enhance the integrity of the joint; and third, to improve the shear resistance of the joint. The spatial steel mesh formed by binding the additional tie bars 15 and the connecting stirrups 16 is an important guarantee for the good mechanical properties of the post-cast strip joint.

[0047] Furthermore, the post-cast strip formed at the 13 close-fitting joints has a width of 75mm and a depth of 120mm. These dimensions were determined after multi-objective optimization. The 75mm width provides ample operating space for the installation and binding of the additional tie bars 15, connecting stirrups 16, and other transverse connecting steel reinforcement components. It also ensures that the vibrator can be smoothly inserted and fully vibrated during the pouring of the post-cast concrete, making it a key dimension for ensuring construction quality. The 120mm depth matches the common thickness of precast floor slabs (typically 130mm to 150mm). This depth ensures a sufficiently large bonding area between the post-cast concrete and the precast floor slab, generating a good shear key effect, while also ensuring that the post-cast section has sufficient cross-sectional height to bear the design internal forces. This specific dimension, while meeting structural stress and construction requirements, minimizes the amount of on-site post-cast concrete and wet work, balancing performance and efficiency.

[0048] A construction method for connection nodes in a modular concrete building structure includes the following steps:

[0049] S1. Vertical Connection Construction: After laying the grout 3 on the foundation layer 1, hoist the first-layer module structural column 2 into position, aligning its pre-embedded first-layer module anchor bars 6 with the pre-embedded foundation anchor bars 5 of the foundation layer 1; install the metal corrugated pipe 4 at the joint, and inject grout 7 through its grouting port 8 until it is filled and cured, completing the first-layer installation. The specific operation is as follows: First, accurately mix the grout 3 according to the design mix ratio. Measure and mark the lines on the top surface of the foundation layer 1 to determine the module positioning line. Then, lay the grout 3 within the line and smooth it to the designed thickness with a screed. Use a crane to slowly lift and lower the first-layer box-type module (its corner or edge is the first-layer module structural column 2). Multiple workers cooperate to make fine adjustments using pry bars and jacks to ensure the module is accurately positioned and that the pre-embedded anchor bars 6 at the bottom of the module can smoothly pass through the grout 3 layer and connect with the foundation anchor bars 5. The connection deviation should be less than 5mm. Next, the segmented or integral corrugated metal pipe 4 is fitted over the outside of the butted steel reinforcement bundle, ensuring the corrugated pipe is vertical, with its lower end inserted into the pre-reserved positioning groove in the lower layer or tightly attached to the lower layer component. Finally, a dedicated grouting device is connected, and the grouting material 7, prepared according to the specifications, is injected through the grouting port 8. A "pressure grouting, low inlet, high outlet" process is used, with the grouting pressure preferably between 0.5 MPa and 1.0 MPa, until the grouting material 7 flows smoothly from the outlet at the top of the corrugated metal pipe 4, and the grout consistency is uniform. The outlet is then sealed and pressure maintained for approximately 30 seconds. After grouting is completed, the grouting material 7 is kept warm and moist for curing. Subsequent construction or load-bearing can only proceed after the strength of the cured test blocks reaches the design requirements (usually not less than 35 MPa).

[0050] S2. Repeated Vertical Connection Construction: Lay grout 3 on top of the installed modules, hoist the upper module structural column 9 into position, aligning the pre-embedded upper module anchor bars 11 with the pre-embedded lower module anchor bars 10 of the lower module, and repeat the grouting connection process to complete the upper module installation. This step is a standardized repetition of S1, demonstrating the sustainability and efficiency of the process. After cleaning and laying grout 3 on the top surface of the installed first-floor modules, hoist the upper box-type modules. The key is to use measuring instruments (such as total stations and levels) and positioning devices to ensure that the pre-embedded upper module anchor bars 11 of the upper module and the pre-embedded lower module anchor bars 10 extending from the top of the lower module are precisely aligned in three-dimensional space, and the alignment accuracy should meet the specifications. After alignment, install the metal corrugated pipe 4, and repeat the above grouting and curing process. This cycle can be repeated layer by layer and span by span to complete the vertical connection installation of all floor box-type modules, forming a stable main structural framework.

[0051] S3. Horizontal Connection Construction: At the close joint 13 of the floor slab between adjacent module structural columns, clean the post-cast groove 14 and arrange the horizontal connecting steel reinforcement components. Then, erect the formwork and pour post-cast concrete into the post-cast groove 14. After it cures, a horizontal connection node is formed. Horizontal connection construction can be carried out on that floor after the vertical connection installation of two or more adjacent box-type modules on the same floor is completed. First, use special tools to clean the laitance, loose particles, and other debris from the post-cast groove 14 in the close joint 13, and rinse it with a high-pressure water gun, but there should be no standing water. Then, insert the additional tie bars 15 into the post-cast groove 14, and reliably connect their ends to the longitudinal reinforcing bars 18 extending from the floor slab of the adjacent module through straight threaded sleeves, welding, or lap splicing, achieving reinforcement continuity. Next, tie the connecting stirrups 16 at the designed spacing and fix them to the additional tie bars 15 to form a steel reinforcement skeleton. Subsequently, a suspended formwork is installed at the bottom of the close-fitting joint 13, with the edges of the modules used as side forms on both sides, forming a U-shaped pouring groove with a width of 75mm and a depth of 120mm. Finally, fine-aggregate concrete with a strength grade one grade higher than the precast floor slab concrete and containing a micro-expansion agent is poured. The concrete slump should be 180mm ± 20mm. It is carefully compacted using an immersion vibrator, and the surface is smoothed and polished. After pouring, it is promptly covered with plastic film or geotextile for heat preservation and moisture retention curing, which should last for no less than 14 days. Once the post-poured concrete reaches the required strength, the formwork is removed, forming a complete and robust horizontal connection node, thus integrating the floor slab system.

[0052] Furthermore, in steps S1 and S2, pressure grouting is used when injecting grout 7 into the corrugated metal pipe 4, and injection continues until the grout 7 overflows from the top of the corrugated metal pipe 4. Pressure grouting is the core technical measure to ensure that the grout 7 fills the corrugated metal pipe 4 densely and without voids. A screw-type or piston-type dedicated grouting pump should be used. The grouting pressure should be determined through testing based on the fluidity of the grout 7, the grouting height, and the pipeline resistance, and kept stable, usually controlled within the range of 0.5MPa to 1.0MPa. The grouting operation should be carried out continuously, starting from the lowest grouting port 8. When a homogeneous grout flows out of a higher grouting port, the port should be immediately sealed with a dedicated rubber stopper. Then, injection continues to the next grouting port, and so on, until all grouting ports are filled and sealed. After all grout outlets are sealed, the grouting pressure should be maintained for at least 30 seconds to ensure that the grout completely fills the gaps at the farthest end of the metal corrugated pipe 4 and the internal voids such as the gaps between the reinforcing bars. This standardized process of "pressure grouting, low-position grouting, high-position grouting, and pressure holding" can effectively remove air and moisture from the duct, ensuring that the grouting material 7 fully bonds with the surface of the reinforcing bars and the inner wall of the corrugated pipe, thereby ensuring that the vertical connection nodes meet the design bearing capacity and seismic performance requirements.

[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular concrete building structure connection node, characterized in that, It includes a basic module, at least one upper-level module, vertical connection components, and horizontal connection components; The basic module includes a basic layer (1) and a first-layer module structure column (2) disposed thereon; The upper module includes an upper module structure column (9) disposed above the first-layer module structure column (2). The vertical connection component includes a reserved anchor bar embedded in the structural column of the adjacent module, a metal corrugated pipe (4) sleeved at the connection of the reserved anchor bar, and grout (7) filled in the metal corrugated pipe (4) to realize the vertical force connection between modules; The horizontal connection component includes a tight joint (13) formed between adjacent module structural columns and floor slabs, a post-cast groove (14) opened at the tight joint (13), and post-cast concrete filled in the post-cast groove (14), for realizing horizontal force connection between modules.

2. The modular concrete building structure connection node according to claim 1, characterized in that, The base layer (1) and the first-layer module structure column (2), as well as the first-layer module structure column (2) and the upper module structure column (9), are all covered with mortar (3).

3. A modular concrete building structure connection node according to claim 1, characterized in that, The side wall of the metal corrugated pipe (4) is provided with a grouting port (8).

4. A modular concrete building structure connection node according to claim 1, characterized in that, The cross-sections of the first-layer module structure column (2) and the upper module structure column (9) are each provided with at least three of the metal corrugated pipes (4) spaced apart along the length direction.

5. A modular concrete building structure connection node according to claim 1, characterized in that, Inside the metal corrugated pipe (4) located at the corner of the modular structure column, there are four sets of reserved anchor bars, and four sets of grout-anchored post-installed steel bars (12) are correspondingly installed on its outer side.

6. A modular concrete building structure connection node according to claim 1, characterized in that, Inside the metal corrugated pipe (4) located at the end of the column side of the modular structure, there are two sets of reserved anchor bars, and two sets of grout-anchored post-installed steel bars (12) are correspondingly installed on its outer side.

7. A modular concrete building structure connection node according to claim 1, characterized in that, The post-cast groove (14) is provided with a transverse connecting steel reinforcement assembly, which includes additional tie bars (15) and connecting stirrups (16).

8. A modular concrete building structure connection node according to claim 1, characterized in that, The post-cast strip formed at the tight joint (13) has a width of 75mm and a depth of 120mm.

9. A construction method for a modular concrete building structure connection node as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Vertical connection construction: After laying the grout (3) on the foundation layer (1), hoist the first-floor module structural column (2) into place, aligning the pre-embedded anchor bars (6) of the first-floor module with the pre-embedded anchor bars (5) of the foundation layer (1); install the metal corrugated pipe (4) at the joint, and inject grout (7) through its grouting port (8) until it is filled and cured, thus completing the first-floor installation; S2. Repeated vertical connection construction: Lay grout (3) on the top of the installed module, hoist the upper module structural column (9) into place, align the pre-embedded upper module reserved anchor bar (11) with the pre-embedded lower module reserved anchor bar (10) of the lower module, and repeat the grouting connection process to complete the installation of the upper module; S3. Horizontal connection construction: At the close joint (13) of the floor slab of the adjacent module structural column, clean the post-pouring groove (14) and arrange the horizontal connection steel reinforcement assembly. Then, formwork is erected and post-pouring concrete is poured into the post-pouring groove (14). After it solidifies, a horizontal connection node is formed.

10. A construction method for a modular concrete building structure connection node according to claim 9, characterized in that, In steps S1 and S2, pressure grouting process is used when injecting grout (7) into the metal corrugated pipe (4), and the injection continues until the grout (7) overflows from the top of the metal corrugated pipe (4).

Images