Rigid connection nodes and construction methods for modular concrete buildings

Abstract

This invention discloses a rigid connection node for modular concrete buildings and its construction method. The rigid connection node includes a modular composite beam, a modular column, a post-cast node core area, connecting steel bars, forming ducts, and fasteners. The connecting steel bars pass through forming ducts embedded in the modular composite beam and modular column to connect adjacent modules and are reliably fixed to end plates by fasteners. The post-cast node core area is filled with concrete, ultra-high performance concrete, or high-strength grout to form a whole. Compared with the prior art, this invention ensures reliable transmission of positive bending moment at the beam-column joint by setting connecting steel bars and the post-cast node core area, and enhances the shear bearing capacity of the joint, achieving a rigid connection in the node area. The force transmission path is clear, the structure is simple, and construction is convenient. The rigid connection node of this invention effectively solves the problems of ambiguous force transmission paths and complex connections in existing semi-rigid connection nodes for modular columns, combining performance and construction advantages.

Description

Technical Field

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

[0002] As a new type of building, modular concrete construction uses precast concrete modules that are precisely manufactured in a factory and then quickly assembled on the construction site. This process achieves standardization, efficiency, and environmental friendliness in the construction process. Compared with steel structure modules, it has a significant cost advantage and has broad application prospects in various fields such as residential, commercial, and public facilities.

[0003] The connection of adjacent modular column nodes is a key technology in modular concrete buildings. Existing technologies use steel connectors, energy dissipation devices, prestressing and other technical means to ensure the force transmission performance of the node area and enhance the ductility of the node. However, they generally have problems such as complex node structure and complicated construction process. Moreover, most of them are semi-rigid connections, which have complex stress performance and greatly increase the design difficulty.

[0004] Therefore, how to simplify the node construction, achieve rigid connection between adjacent module columns, improve construction efficiency, simplify design methods, and ensure a more reliable connection in the node area is an urgent technical problem to be solved. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a concrete modular building connection node and its construction method, which addresses the problems of complex structure, unclear force transmission path and cumbersome design method of existing connection nodes.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A rigid connection node for a modular concrete building includes a first modular composite beam, a second modular composite beam, a modular column, a post-cast node core area, connecting steel bars, forming ducts, and fasteners. The first modular composite beam is parallel to the connection direction of the modular column and includes a precast beam body, a precast haunch area, and a post-cast composite layer. The second modular composite beam is perpendicular to the connection direction of the modular column and includes a second precast beam body and a post-cast composite portion. The top of the modular column has a groove, and the grooves of adjacent modular columns are joined together to form a whole. Post-casting is carried out in the grooves of adjacent modular columns and in the gaps between them to form the post-cast node core area. The forming duct is pre-embedded at the same horizontal height as the precast haunch area and the modular column. The connecting steel bar passes through the forming duct to connect adjacent modular columns and is fixed to the side surface of the modular column away from the post-cast node core area by fasteners. The top reinforcement of the first adjacent modular composite beam is set through the post-cast node core area.

[0008] In one embodiment, the post-cast composite layer is located at the top of the precast beam, and the top reinforcement bar runs through it along the length of the modular composite beam; the precast haunch area is located at both ends of the bottom of the precast beam, and stirrups of the modular composite beam are distributed therein.

[0009] In one embodiment, the post-cast composite portion is located at the top of the precast beam two and together with the precast beam two forms a rectangular cross section. The top reinforcement two passes through it along the length direction of the modular composite beam two and extends into the top of the core area of ​​the post-cast node.

[0010] In one embodiment, ordinary concrete, ultra-high performance concrete, or high-strength grout is poured into the core area of ​​the post-cast node to ensure the effective transfer of compressive stress in the core area of ​​the node. The interface between the core area of ​​the post-cast node and the groove side of the module column is a natural forming surface, a rough surface, or a keyway. The post-cast composite layer of the first modular composite beam and the post-cast composite part of the second modular composite beam are cast with ordinary concrete.

[0011] In one embodiment, the forming duct is reliably fixed to the reinforcing cage of the precast haunch area, and the forming duct extends through into the reinforcing cage of the modular column, with its end near the core area of ​​the post-cast node flush with the side surface of the modular column.

[0012] In one embodiment, to prevent localized pressure damage, a reinforcing end plate is pre-embedded on the side of the precast haunch area away from the core area of ​​the post-cast node. The reinforcing end plate is reliably fixed to the forming channel, and the connecting steel rod is fixed to the side of the reinforcing end plate away from the core area of ​​the post-cast node by fasteners.

[0013] In one embodiment, the top of the module, composed of the first modular composite beam, the second modular composite beam, and the modular column, is simultaneously prefabricated as a floor slab, or laid on-site.

[0014] In one embodiment, to enhance the shear resistance of the nodes, one or two shear-resistant steel plates are installed between adjacent module columns. The shear-resistant steel plates are welded to the pre-embedded steel plates on the side of the module columns through fillet welds.

[0015] The present invention also provides a construction method for the rigid connection node of the concrete modular building, comprising the following steps:

[0016] Step 1: In the factory, the precast beam body 1 of modular composite beam 1, the precast beam body 2 of modular composite beam 2, and the steel cage of the modular column are tied together, and the forming duct is fixed to the steel cage of the precast beam body 1 and the modular column.

[0017] Step 2: In the factory, the precast beam 1, precast beam 2 and modular columns are poured to form an integral module;

[0018] Step 3: After positioning and hoisting the precast modules at the construction site, pass the connecting steel rods through the forming channels at the same horizontal height of the adjacent precast modules, and fix the connecting steel rods with fasteners.

[0019] Step 4: Use sealant or cover plate to seal the gaps between adjacent module columns and adjacent module composite beams to prevent grout leakage;

[0020] Step 5: After installing the top reinforcement bar 1 of modular composite beam 1 and the top reinforcement bar 2 of modular composite beam 2, pour the concrete for the post-cast composite layer and the post-cast composite part. When ordinary concrete is used in the core area of ​​the post-cast node, it is poured simultaneously with the post-cast composite layer and the post-cast composite part. When high-strength grouting material or ultra-high performance concrete is used in the core area of ​​the post-cast node, the core area of ​​the post-cast node is poured first, and then the concrete for the post-cast composite layer and the post-cast composite part is poured.

[0021] In one embodiment, when shear-resistant steel plates are installed, in step 1 the embedded steel plates are fixed to the reinforcing cage of the module column; in step 3 the shear-resistant steel plates are welded to the embedded steel plates of adjacent module columns.

[0022] Compared with the prior art, the present invention can effectively transfer the tensile and compressive stress in the node area by setting the connecting steel bar, and effectively transfer the compressive stress in the node area through the core area of ​​the post-cast node. Together with the through top reinforcement, it realizes the transfer of positive and negative bending moments in the node area, and realizes the rigid connection of the modular column node.

[0023] The invention also adds a shear-resistant steel plate, which further enhances the shear bearing capacity of the joint. At the same time, the shear-resistant steel plate deforms and dissipates energy under rare earthquakes, thus enhancing the seismic performance of the joint.

[0024] The node components of this invention are simple, the force transmission path is clear, and the construction is convenient, which solves the application pain points of existing concrete modular semi-rigid connection nodes. Attached Figure Description

[0025] Figure 1 This is a three-dimensional schematic diagram of the rigid connection node of the modular building according to the present invention.

[0026] Figure 2 This is a three-dimensional schematic diagram of a modular composite beam in an embodiment of the present invention.

[0027] Figure 3 This is a three-dimensional schematic diagram of the second modular composite beam in an embodiment of the present invention.

[0028] Figure 4 This is a three-dimensional schematic diagram of the node core area in an embodiment of the present invention.

[0029] Figure 5 This is a three-dimensional schematic diagram of the module column in an embodiment of the present invention.

[0030] Figure 6 This is a three-dimensional schematic diagram of the reinforcing end plate and the forming channel being integrally fixed in one embodiment of the present invention.

[0031] Figure 7 This is a three-dimensional schematic diagram of the arrangement of module columns and shear-resistant steel plates in one embodiment of the present invention.

[0032] Figure 8 This is a three-dimensional schematic diagram of the arrangement of module columns and shear-resistant steel plates in another embodiment of the present invention.

[0033] In the picture:

[0034] 1-Module composite beam one; 11-Precast beam one; 12-Precast haunch area; 13-Post-cast composite layer; 131-Top reinforcement one; 2-Module composite beam two; 21-Precast beam two; 22-Post-cast composite part; 221-Top reinforcement two; 3-Module column; 31-Groove; 32-Embedded steel plate; 4-Core area of ​​post-cast node; 5-Connecting steel bar; 6-Forming duct; 7-Fastener; 8-Reinforcing end plate; 9-Shear steel plate. Detailed Implementation

[0035] The specific technical solutions of the present invention are described below with reference to the embodiments.

[0036] This invention relates to a rigid connection node for modular concrete buildings. It aims to achieve a rigid connection between modular concrete columns through a core area of ​​the integrally cast node and connecting steel bars, thereby clarifying the force transmission path, improving structural safety, and simplifying the design process. (Reference) Figure 1 As shown, it includes a modular composite beam 1, a modular composite beam 2, a modular column 3, a post-cast node core area 4, connecting steel bars 5, forming ducts 6, and fasteners 7. The modular composite beam 1 is parallel to the connection direction of the modular column 3 and includes a precast beam body 11, a precast haunch area 12, and a post-cast composite layer 13; the modular composite beam 2 is perpendicular to the connection direction of the modular column 3 and includes a precast beam body 21 and a post-cast composite portion 22. The top of the modular column 3 is provided with a groove 31, and the grooves 31 of adjacent modular columns 3 are joined together to form a whole. The post-cast node core area 4 is formed by post-casting in the grooves 31 of adjacent modular columns 3 and in the gap between them. The forming channel 6 is pre-embedded in the prefabricated haunch area 12 at the same horizontal height as the modular column 3. The connecting steel bar 5 passes through the forming channel 6 to connect the adjacent modular columns 3, and is fixed to the side surface of the modular column 3 away from the post-cast node core area 4 by fasteners 7. The top reinforcement 131 of the adjacent modular composite beam 1 is set through the post-cast node core area 4.

[0037] refer to Figure 2As shown, in this structure, the post-cast composite layer 13 is located at the top of the precast beam 11, and the top reinforcement 131 runs through it along the length of the modular composite beam 1. The top reinforcement 131 of the adjacent modular composite beam 1 runs through the top of the post-cast node core area 4. To enhance anchorage, an anchor plate is provided at one end of the bottom reinforcement of the precast beam 11 that extends into the post-cast node core area 4. The precast haunch area 12 is located at both ends of the bottom of the precast beam 11, and the stirrups of the modular composite beam 1 are distributed therein. The forming channel 6 is pre-embedded and located inside the stirrups. The stirrups can restrain the concrete of the precast haunch area 12, enhance its ductility, and prevent splitting failure. The precast beam 11 and the precast haunch area 12 are integrally cast in the factory.

[0038] refer to Figure 3 As shown, in this structure, the post-cast composite portion 22 is located on top of the precast beam 21 and together with the precast beam 21 forms a rectangular cross-section. The top reinforcement 221 extends through the composite beam 2 along its length and reaches the top of the post-cast node core area 4. To enhance anchorage, an anchoring plate can be installed at the end of the top reinforcement 221 that extends into the post-cast node core area 4. In some embodiments of the present invention, there is a splice joint between adjacent composite beams 2, typically not exceeding 2 cm.

[0039] In this structure, taking into account both the stress performance and construction cost, the post-cast composite layer 13 of the modular composite beam 1 and the post-cast composite part 22 of the modular composite beam 2 are both cast with ordinary concrete. When the core area 4 of the post-cast node is made of ultra-high performance concrete or high-strength grouting material, the core area 4 of the post-cast node should be cast first. After the core area casting material reaches the design strength, the ordinary concrete of the modular composite beam is then cast.

[0040] In this structure, the gap between the grooves 31 of adjacent module posts 3 is the same width as the installation gap of adjacent module posts 3, and usually does not exceed 2cm.

[0041] Figure 4 A three-dimensional schematic diagram of the node core area in an embodiment of the present invention is provided. As shown in the figure, the range of the post-cast node core area 4 includes the groove 31 of the adjacent module column 3 and the gap between them. Different materials can be selected for casting according to the actual needs of the project, including ordinary concrete, ultra-high performance concrete or high-strength grouting material, etc., to ensure the effective transmission of compressive stress in the node core area.

[0042] In this structure, considering the transmission of beam end shear force in the node core area, in order to enhance the interface shear bearing capacity between the post-cast node core area 4 and the precast modular column 3, the interface where the post-cast node core area 4 intersects with the side of the groove 31 of the modular column 3 is preferably a rough surface or a keyway, or a naturally formed surface can also be used.

[0043] In this structure, the forming channel 6 extends through into the steel cage 3 of the module column, and its end that is not connected to the reinforcing end plate 8 is flush with the side surface of the module column 3.

[0044] In some embodiments of the present invention, to prevent localized pressure failure of the precast haunch area 12 concrete, a reinforcing end plate 8 is pre-embedded on the side of the precast haunch area 12 away from the core area 4 of the post-cast node. The reinforcing end plate 8 is reliably fixed to the forming channel 6, and the connecting steel rod 5 is fixed to the side of the reinforcing end plate 8 away from the core area 4 of the post-cast node by fasteners 7. The reinforcing end plate 8 can be made of ordinary carbon steel or stainless steel. To facilitate channel positioning, the forming channel 6 and the reinforcing end plate 8 can be effectively fixed together in advance, such as... Figure 6 As shown, it is then pre-embedded in the prefabricated armhole area 12 and module column 3. The forming channel can be formed by welding thin-walled metal pipe, plastic pipe or core pulling.

[0045] In some embodiments of the present invention, the top surface of the concrete module can be constructed in different ways. For example, a precast floor slab can be precast in the factory at the same time as the top of the module composed of the module composite beam 1, the module composite beam 2, and the module column 3. Alternatively, a formwork-free floor slab can be laid on site or a floor formwork can be erected before pouring the floor concrete.

[0046] In this structure, to enhance the shear resistance of the nodes, one or two shear-resistant steel plates 9 are installed between adjacent modular columns 3. The shear-resistant steel plates 9 are welded to the pre-embedded steel plates 32 on the side of the modular columns 3 via fillet welds. The shear force between the modular columns can be transferred through the shear-resistant steel plates 9. Under rare earthquake conditions, the shear-resistant steel plates 9 deform and dissipate energy, thus enhancing the ductility and energy dissipation capacity of the node area. Figure 7 As shown, when the shear plate 9 is placed on the side of the column away from the composite beam 2 of the module, it is placed at the same horizontal height as the core area 4 of the post-cast node. Figure 8 As shown, when the shear steel plate 9 is placed on the side of the column near the second modular composite beam 2, it is placed below the core area 4 of the post-cast node.

[0047] The present invention further provides a construction method for rigid connection nodes in modular concrete buildings, based on modular construction technology, to improve construction efficiency and effectively control quality and cost. Specifically, the construction method includes the following steps:

[0048] Step 1: In the factory, the precast beam body 11 of modular composite beam 1, the precast beam body 21 of modular composite beam 2, and the steel cage of modular column 3 are tied together, and the forming duct 6 is fixed to the steel cage of precast beam body 11 and modular column 3.

[0049] This step is fundamental to the entire construction process. Before starting the binding, it must be ensured that all reinforcing steel materials meet the design requirements, including the specifications, quantity, and strength grade of the steel bars. The surfaces of the reinforcing steel bars should be clean, avoiding rust and contamination to ensure good connections. The design of the reinforcing cage should take into account load-bearing capacity and seismic performance, ensuring its strength and stability after concrete pouring. The fixing of the forming duct 6 should ensure its accurate positioning so that the connecting steel bars 5 can pass through smoothly during subsequent construction.

[0050] Step 2: In the factory, the precast beam 11, precast beam 21 and module column 3 are cast to form an integral module.

[0051] The main purpose of this step is to pour the precast modules. During the process, care should be taken to control the flowability of the concrete to avoid segregation and air bubbles. After pouring, the concrete is vibrated to eliminate air bubbles and increase density. Proper curing and maintaining a moist environment are essential after pouring to prevent cracking and insufficient strength.

[0052] Through steps 1 and 2 above, the construction of the prefabricated part of the project was completed.

[0053] Step 3: After positioning and hoisting the precast modules at the construction site, pass the connecting steel rod 5 through the forming channel 6 at the same horizontal height as the adjacent precast modules, and fix the connecting steel rod 5 with fasteners 7.

[0054] This step completes the on-site positioning and hoisting. Fastener 7 can be bolts or similar, and the fixing method can be bolt connection, to ensure a firm connection between modules and enhance the stability of the overall structure.

[0055] Step 4: Use sealant or cover plate to seal the gaps between adjacent module columns 3 and adjacent module composite beams 2 to prevent grout leakage.

[0056] The main purpose of this step is to seal the gaps. After the modules are connected, a suitable sealant is selected and filled according to the size of the gaps and design requirements, or a cover plate is used to cover them to prevent grout leakage and moisture penetration. The use of sealant should ensure the gaps are sealed to prevent water seepage or structural loosening during subsequent construction or use.

[0057] Step 5: After installing the top reinforcement 131 of modular composite beam 1 and the top reinforcement 221 of modular composite beam 2, pour the concrete for the post-cast composite layer 13 and the post-cast composite part 22. When ordinary concrete is used for the core area 4 of the post-cast node, it is poured at the same time as the post-cast composite layer 13 and the post-cast composite part 22. When high-strength grouting material or high-strength concrete is used for the core area 4 of the post-cast node, the core area of ​​the post-cast node is poured first, and then the concrete for the post-cast composite layer 13 and the post-cast composite part 22 is poured.

[0058] The main purpose of this step is to pour the post-concrete. First, the connection is ensured by inserting two top reinforcing bars, and then the concrete is poured. After pouring, proper curing is carried out to ensure the strength and stability of the concrete.

[0059] In some embodiments of the present invention, when the shear-resistant steel plate 9 is provided, in step 1 the embedded steel plate 32 is fixed to the reinforcing cage of the module column 3; in step 3 the shear-resistant steel plate 9 is welded to the embedded steel plate 32 of the adjacent module column 3.

[0060] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations and substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A rigid connection node for modular concrete buildings, characterized in that, The system includes a modular composite beam one (1), a modular composite beam two (2), a modular column (3), a post-cast node core area (4), connecting steel bars (5), forming ducts (6), and fasteners (7); the modular composite beam one (1) is parallel to the connection direction of the modular column (3) and includes a precast beam body one (11), a precast haunch area (12), and a post-cast composite layer (13); the modular composite beam two (2) is perpendicular to the connection direction of the modular column (3) and includes a precast beam body two (21) and a post-cast composite part (22); the top of the modular column (3) is provided with a groove (31), and adjacent modular columns (3) The grooves (31) are joined together as a whole, and the post-cast node core area (4) is formed by post-casting in the grooves (31) of adjacent module columns (3) and the gap between them; the forming channel (6) is embedded in the same horizontal height position of the prefabricated haunch area (12) and the module column (3); the connecting steel bar (5) passes through the forming channel (6) to connect the adjacent module column (3), and is fixed to the side surface of the module column (3) away from the post-cast node core area (4) by fasteners (7); the top reinforcement (131) of the adjacent module composite beam (1) is set through the post-cast node core area (4).

2. The rigid connection node for modular concrete buildings according to claim 1, characterized in that, The post-cast composite layer (13) is located on top of the precast beam body (11), and the top reinforcement (131) runs through it along the length of the modular composite beam (1); The precast haunch area (12) is located at both ends of the bottom of the precast beam body (11), and the stirrups of the modular composite beam (1) are distributed therein.

3. The rigid connection node for modular concrete buildings according to claim 1, characterized in that, The post-cast composite portion (22) is located at the top of the precast beam body two (21) and together with the precast beam body two (21) forms a rectangular section. The top reinforcement two (221) runs through it along the length direction of the module composite beam two (2) and extends into the top of the post-cast node core area (4).

4. The rigid connection node for modular concrete buildings according to claim 1, characterized in that, Ordinary concrete, ultra-high performance concrete or high-strength grouting material are poured into the core area (4) of the post-cast node to ensure the effective transmission of compressive stress in the core area of ​​the node. The interface between the core area (4) of the post-cast node and the side of the groove (31) of the module column (3) is a natural forming surface, a rough surface or a keyway. The post-cast composite layer (13) of the first module composite beam (1) and the post-cast composite part (22) of the second module composite beam (2) are cast with ordinary concrete.

5. The rigid connection node for modular concrete buildings according to claim 1, characterized in that, The forming duct (6) is reliably fixed to the reinforcing cage of the precast haunch area (12). The forming duct (6) extends through into the reinforcing cage of the module column (3), and its end near the core area (4) of the post-cast node is flush with the side surface of the module column (3).

6. The rigid connection node for modular concrete buildings according to claim 1, characterized in that, To prevent damage from local pressure, a reinforcing end plate (8) is pre-embedded on the side of the precast haunch area (12) away from the core area (4) of the post-cast node. The reinforcing end plate (8) is reliably fixed to the forming channel (6), and the connecting steel rod (5) is fixed to the side of the reinforcing end plate (8) away from the core area (4) of the post-cast node by fasteners (7).

7. The rigid connection node for modular concrete buildings according to claim 1, characterized in that, The top of the module, composed of the first modular composite beam (1), the second modular composite beam (2), and the modular column (3), is prefabricated as a whole, or laid on site.

8. The rigid connection node for modular concrete buildings according to claim 1, characterized in that, To enhance the shear resistance of the nodes, one or two shear-resistant steel plates (9) are installed between adjacent module columns (3). The shear-resistant steel plates (9) are welded to the pre-embedded steel plates (32) on the side of the module columns (3) through fillet welds.

9. A construction method for rigid connection nodes in modular concrete buildings according to any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1: In the factory, the precast beam body 1 (11) of the modular composite beam 1 (1), the precast beam body 2 (21) of the modular composite beam 2 (2) and the steel cage of the modular column (3) are tied together, and the forming duct (6) is fixed to the steel cage of the precast beam body 1 (11) and the modular column (3). Step 2: In the factory, the precast beam 1 (11), precast beam 2 (21) and modular column (3) are poured to form an integral module; Step 3: After positioning and hoisting the precast modules at the construction site, pass the connecting steel rod (5) through the forming channel (6) at the same horizontal height of the adjacent precast modules, and fix the connecting steel rod (5) with fasteners (7). Step 4: Use sealant or cover plate to seal the gaps between adjacent module columns (3) and adjacent module composite beams (2) to prevent grout leakage; Step 5: After installing the top reinforcement 1 (131) of the modular composite beam 1 (1) and the top reinforcement 2 (221) of the modular composite beam 2 (2), pour the concrete for the post-cast composite layer (13) and the post-cast composite part (22). When the post-cast node core area (4) is made of ordinary concrete, it is poured at the same time as the post-cast composite layer (13) and the post-cast composite part (22). When the post-cast node core area (4) is made of high-strength grouting material or ultra-high performance concrete, the post-cast node core area is poured first, and then the concrete for the post-cast composite layer (13) and the post-cast composite part (22) is poured.

10. The construction method for rigid connection nodes in modular concrete buildings according to claim 9, characterized in that, To enhance the shear resistance of the nodes, one or two shear-resistant steel plates (9) are installed between adjacent modular columns (3). The shear-resistant steel plates (9) are welded to the embedded steel plates (32) on the side of the modular columns (3) through fillet welds. At this time, in step 1, the embedded steel plates (32) are fixed to the reinforcing cage of the modular columns (3). In step 3, the shear-resistant steel plates (9) are welded to the embedded steel plates (32) of the adjacent modular columns (3).

Images