Fabricated profile steel reinforced ECC-inorganic glue composite bamboo joint and construction method

Abstract

The invention provides a fabricated profile steel reinforced ECC-inorganic glue composite bamboo joint and a construction method, relates to the field of composite joints, and aims to solve the problem that a joint structure formed by combining ECC and profile steel is difficult to adapt to bio-based materials such as bamboos and the like. Cross-shaped inserting plates extend out of the two ends of a section steel column in a prefabricated section steel reinforced ECC joint core area and are matched with cross-shaped inserting grooves formed in the ends of inorganic glue composite bamboo columns in an inserted mode, and webs of connecting pieces fixed to section steel ECC beams in the prefabricated joint core area are used for being connected with linear butt joint grooves in the ends of the inorganic glue composite bamboo beams in an inserted mode. The lower flange plate supports the inorganic glue composite bamboo beam, the splicing position is filled with the adhesive, and the fastener is installed, so that the problem of low connection rigidity is effectively solved, and compared with traditional bamboo-wood structure beam column joint connection, when the joint is damaged, a beam end plastic hinge moves outwards, and the overall rigidity of the joint is improved; cross grain splitting damage caused by beam end local stress concentration is avoided, and the problem that an existing ECC type steel joint technology cannot be effectively combined with inorganic glue composite bamboo is solved.

Description

Technical Field

[0001] The present invention relates to the field of composite joints, and particularly to a prefabricated steel-reinforced ECC-inorganic glue composite bamboo joint and a construction method thereof. Background Art

[0002] Traditional bamboo-wood structure beam-column joints mostly adopt steel packing plates - bolt connections. The high strength of steel makes up for the anisotropy and weak local compressive capacity of bamboo and wood, but there are problems such as low connection stiffness, easy transverse splitting failure at the beam end, and poor energy dissipation capacity. Inorganic glue composite bamboo is environmentally friendly and has good fire resistance, but the traditional wooden structure beam-column joint connection technology still makes the joint area face challenges of insufficient bearing capacity and ductility, restricting the application and development of inorganic glue composite bamboo buildings.

[0003] In the current engineering technology field, Engineered Cementitious Composite (ECC) has been widely introduced into the beam-column joint area due to its high ductility, strain hardening characteristics, and excellent fire resistance to improve the stiffness, energy dissipation capacity, and durability of the joints. Combining ECC with steel in the joint core area can make full use of the superior crack control ability, fire resistance of ECC, as well as the high strength and high ductility characteristics of steel, comprehensively improving the bearing capacity, energy dissipation performance, and durability of the joints. In the current prefabricated structure combining ECC with steel beams, the prefabricated steel-concrete composite column is formed by the core H-shaped steel column, longitudinal bars outside the H-shaped steel column, stirrups, and concrete inside it; a beam-column joint area is provided in the middle of the prefabricated steel-concrete composite column, and the beam-column joint area is formed by pouring an ECC coating layer; the beam-column joint area is used to connect the prefabricated steel beam. For the disclosed steel-ECC joints, the connection method between the joint area and the beam-column is mainly through welding or the cooperation of extended end plates and bolts for assembly. This connection method is applicable to steel structures or steel-concrete composite structures, but it is not adaptively designed for the anisotropic characteristics of bio-based materials such as bamboo and wood. Especially for inorganic glue composite bamboo materials, the connection between inorganic glue composite bamboo beams and columns is different from that of steel structures or steel-concrete composite structures. If an internal steel plate is used in inorganic glue composite bamboo materials, it will cause the internal steel plate to be unable to form an effective interfacial bond with the bamboo fiber matrix, affecting its strength and stress effect, and it is difficult to meet the application requirements of the existing ECC steel joint technology in green buildings and high-performance composite structures. Summary of the Invention

[0004] The object of the present invention is to address the deficiencies existing in the prior art and provide an assembled steel-reinforced ECC-inorganic glue composite bamboo joint and a construction method. Cross-shaped plug-in plates extend from both ends of the steel ECC column in the core area of the precast joint to be plugged into the cross-shaped plug-in grooves opened at the ends of the inorganic glue composite bamboo columns, and fasteners and adhesives are used to establish the connection between the inorganic glue composite bamboo columns and the steel ECC columns. The web of the connector fixed on the steel ECC beam is used to plug into the linear docking groove at the end of the inorganic glue composite bamboo beam, and the lower flange plate of the connector supports the inorganic glue composite bamboo beam. The upper surfaces of the inorganic glue composite bamboo beam and the steel ECC beam are respectively fitted with a top plate. Through holes are opened in the top plate and are used in conjunction with fasteners to establish the connection between the top plate, the lower flange plate, the inorganic glue composite bamboo beam and the steel ECC beam. Adhesives are filled in the plug-in positions and fasteners are installed, effectively solving the problem of low connection stiffness. Compared with the connection of traditional bamboo and wood structure beam-column joints, when the joint fails, the plastic hinge at the beam end moves outwards, improving the overall bearing capacity of the joint; at the same time, it avoids the transverse splitting failure caused by local stress concentration at the beam end, and solves the problem that the existing steel ECC joint technology cannot be effectively combined with inorganic glue composite bamboo; by utilizing the high ductility, strain hardening characteristics and excellent fire resistance of ECC, as well as the high strength and high ductility characteristics of steel, the energy dissipation capacity of the joint is comprehensively improved, enabling the inorganic glue composite bamboo material to be better applied to building structures.

[0005] The first object of the present invention is to provide an assembled steel-reinforced ECC-inorganic glue composite bamboo joint, which adopts the following scheme:

[0006] It includes a steel ECC column and a steel ECC beam connected to its side. Both the steel ECC column and the steel ECC beam are precast components. Cross-shaped plug-in plates extend from both ends of the steel ECC column to be plugged into the cross-shaped plug-in grooves opened at the ends of the inorganic glue composite bamboo columns; through holes are opened in the plug-in plates, and a vertical connection system between the inorganic glue composite bamboo column and the steel ECC column is established by cooperating with fasteners; a connector is connected to one end of the steel ECC beam away from the joint area. The connector includes a top plate and an integral lower flange plate and web. Through holes are opened in both the lower flange plate and the top plate. The web is used to plug into the linear docking groove at the end of the inorganic glue composite bamboo beam, and the lower flange plate supports the inorganic glue composite bamboo beam that it cooperates with. The top plate fits the upper surfaces of the inorganic glue composite bamboo beam and the steel ECC beam, and a transverse connection system between the inorganic glue composite bamboo beam-connector-steel ECC beam is established by cooperating with fasteners; adhesives are filled in the gaps between the plug-in plates and the plug-in grooves and between the web and the docking grooves.

[0007] Among them, the adhesive can be an organic glue or an inorganic glue. For working conditions with higher requirements for bonding performance and lower requirements for fire resistance, an organic glue can be used, while for applications with higher requirements for fire resistance, an inorganic glue can be used.

[0008] Further, the plug-in board includes a first board and a second board that are vertically and crosswise distributed. Through holes are respectively formed in the first board and the second board, and fasteners are respectively fitted thereto.

[0009] Further, the orientation of the fastener fitted to the through hole on the first board is perpendicular to the space of the fastener fitted to the through hole on the second board.

[0010] Further, the fastener fitted to the through hole on the plug-in board penetrates through the inorganic glue composite bamboo column.

[0011] Further, the through hole positions on the lower flange plate of the connecting member and the top plate correspond to each other and are fixedly connected by fasteners. The fasteners fitted to the lower flange plate are arranged in a staggered manner with the fasteners fitted to the through holes on the web. The fasteners jointly fitted by the lower flange plate and the top plate penetrate through the lower flange plate, the inorganic glue composite bamboo beam, and the top plate. The fasteners fitted to the web penetrate through the inorganic glue composite bamboo beam.

[0012] Further, the profiled steel ECC beam includes a profiled steel beam and ECC wrapped outside the profiled steel beam. The connecting member is fixedly welded to the profiled steel beam and temporarily positioned by embedded fasteners. The fasteners penetrate through the lower flange plate of the connecting member and the top plate of the profiled steel ECC beam and are fastened.

[0013] Further, the profiled steel beam is in an I shape, and the ECC is filled at the connection position between the connecting member and the profiled steel beam. The ECC is distributed between the lower flange plate and the top plate of the connecting member.

[0014] Further, the profiled steel ECC column includes a cruciform core column and side plates connected to the core column. The side plates are distributed at intervals along the circumferential direction of the core column. ECC is filled between the side plates and the core column, and the outside of the side plates is wrapped with ECC. The core column and the plug-in board are of an integral structure, and the profiled steel beam is connected to the side plates.

[0015] The second object of the present invention is to provide a construction method for an assembled profiled steel reinforced ECC-inorganic glue composite bamboo node, including:

[0016] Fix the profiled steel beam on the side of the profiled steel column. After installing the connecting member on the profiled steel beam, pour ECC to form a connected profiled steel ECC column and profiled steel ECC beam. Open corresponding plug-in grooves and docking grooves on the inorganic glue composite bamboo column and the inorganic glue composite bamboo beam, and open a hole for the fastener to pass through;

[0017] Insert the plug-in board at the end of the profiled steel ECC column into the plug-in groove at the end of the inorganic glue composite bamboo column, and inject the adhesive. String the fasteners through the through holes and the holes for locking; insert the web at the end of the connecting member into the docking groove at the end of the inorganic glue composite bamboo beam, and inject the adhesive. String the fasteners through the through holes and the holes for locking.

[0018] Furthermore, the steel ECC column and the steel ECC beam connected to its side constitute the core area of ​​the prefabricated node, and the inorganic glue composite bamboo beam is positioned and supported by the lower flange plate of the connecting piece, so that the end of the inorganic glue composite bamboo beam overlaps the lower flange plate of the connecting piece, and cooperates with the top plate to establish a connection between the inorganic glue composite bamboo beam and the core area of ​​the prefabricated node.

[0019] Compared with the prior art, the present invention has the following advantages and positive effects:

[0020] In view of the problem that the node structure combining ECC and steel is difficult to adapt to bio-based materials such as bamboo and wood, the present invention proposes an assembled steel reinforced ECC-inorganic adhesive composite bamboo node. The two ends of the steel ECC column in the core area of ​​the prefabricated node extend out cross-shaped plug-in plates that are plugged into the cross-shaped plug-in grooves opened at the ends of the inorganic adhesive composite bamboo columns. The web of the connecting piece fixed on the steel ECC beam is used to plug into the I-shaped docking groove at the end of the inorganic adhesive composite bamboo beam. The lower flange plate supports the inorganic adhesive composite bamboo beam. The inorganic adhesive composite bamboo beam and the upper surface of the steel ECC beam are attached to the top plate. The top plate is provided with through holes and cooperates with fasteners to establish a top plate, a lower flange plate, an inorganic adhesive composite bamboo beam and For the connection of steel ECC beams, adhesive is filled at the plug-in position and fasteners are installed, which effectively solves the problem of low connection stiffness. Compared with the traditional bamboo-wood structure beam-column node connection, the plastic hinge at the beam end moves outward when the node is damaged, which improves the overall bearing capacity of the node; at the same time, it avoids the transverse splitting damage caused by local stress concentration at the beam end, and solves the problem that the existing steel ECC node technology cannot be effectively combined with inorganic adhesive composite bamboo; by utilizing the high ductility, strain hardening characteristics and excellent fire resistance of ECC, as well as the high strength and high ductility characteristics of steel, the energy consumption capacity of the node is comprehensively improved, so that the inorganic adhesive composite bamboo material can be better used in building structures.

[0021] The plug-in board is formed by combining a first plate and a second plate that are perpendicular to each other, and can fasten the inorganic adhesive composite bamboo column from two mutually perpendicular directions. Due to the anisotropy of the inorganic adhesive composite bamboo column, the connection in a single direction may become loose or fail when subjected to complex loads. Through fasteners that run vertically in space, the inorganic adhesive composite bamboo column can be constrained in different directions, effectively resisting loads such as tension and shear from all directions, greatly improving the stability of the connection, further enhancing the connection stiffness of the node, and preventing the node from relative displacement or rotation during the force process, thereby improving the stability of the overall structure and better solving the problem of low stiffness of traditional node connections.

[0022] The fasteners matched with the through holes on the plug-in board penetrate the inorganic adhesive composite bamboo column, so that the plug-in board and the inorganic adhesive composite bamboo column form a tight whole. Compared with non-penetrating connections, the penetration design can transfer loads more effectively and avoid damage caused by stress concentration at the connection interface. It ensures that the force can be evenly transmitted from the steel column to the inorganic adhesive composite bamboo column through the plug-in board, reducing local deformation caused by loose connection, thereby further preventing transverse splitting damage, and at the same time improving the energy dissipation capacity of the node, because when subjected to large loads, the penetration fasteners can better participate in the energy dissipation mechanism and dissipate energy through their own deformation and friction with the material.

[0023] The fasteners provided for the through holes on the lower flange plate and the top plate are staggered with the fasteners provided for the through holes on the web plate. The fasteners provided for the lower flange plate and the top plate penetrate the lower flange plate, steel ECC beam and top plate of the connecting piece on one side, and penetrate the lower flange plate, inorganic adhesive composite bamboo beam and top plate of the connecting piece on the other side. At the same time, the fasteners provided for the web plate penetrate the inorganic adhesive composite bamboo beam. The staggered fasteners can make the inorganic adhesive composite bamboo beam receive the fastening force at different positions, avoiding excessive local stress caused by the concentration of fasteners at the same position. The different penetration methods of the lower flange plate, the top plate and the web plate constrain the inorganic adhesive composite bamboo beam from multiple angles, enhance the connection strength between the node area and the inorganic adhesive composite bamboo beam, meet the requirements of the structure under complex stress conditions, and also help to improve the energy dissipation capacity of the node. When subjected to seismic loads, the staggered fasteners can work together from different directions to dissipate energy more effectively.

[0024] Through the "bamboo-glue-steel" synergistic force transmission system, the vertical load is transmitted to the prefabricated node through the prefabricated inorganic glue composite bamboo column through the synergistic action of the plug-in plate and the plug-in slot. In the transverse load transfer path, the bending moment and shear force are transferred from the prefabricated inorganic glue composite bamboo beam to the core area of ​​the node through the connector. After the connector is inserted into the preset docking groove on the prefabricated inorganic glue composite bamboo beam, it is bonded with adhesives and locked with fasteners to form a multi-path force transmission mechanism.

[0025] The overall mechanical properties of the node are enhanced. The synergistic effect of the steel frame and ECC materials significantly improves the node's bending stiffness, ultimate bearing capacity and energy absorption capacity, forming a "strong column and weak beam" mechanical system, which transforms the failure mode from the brittle splitting of traditional bamboo and wood nodes to controllable ductile crushing, ensuring structural safety.

[0026] ECC is filled between the side plates and the core columns, and the side plates are wrapped with ECC. The core columns and the plug-in plates are of an integral structure. The profiled steel beams are welded and fixed to the side plates, making full use of the high strength of the profiled steel and the excellent properties of ECC. On the one hand, by utilizing the ultra-high tensile and shear ductility of ECC, the development of cracks can be effectively controlled, the shear bearing capacity and seismic performance of the joints are improved, and the complex reinforcement in the joint area can be eliminated. On the other hand, since the PVA fibers in the ECC material melt at high temperatures to provide channels for the release of high-temperature and high-pressure gases in the matrix, the good fire resistance of the ECC material effectively solves the problem of poor fire resistance of the internal profiled steel.

[0027] Among them, the adhesive can be an organic adhesive or an inorganic adhesive. For working conditions with higher requirements for bonding performance and lower requirements for fire resistance, an organic adhesive can be used, while for those with higher requirements for fire resistance performance, an inorganic adhesive can be used.

[0028] The inorganic adhesive has no problem of releasing harmful substances such as formaldehyde and has low production costs. A large amount of industrial waste such as fly ash and slag is used in the production process of ECC, greatly reducing the amount of cement used. The environmental friendliness of the inorganic adhesive composite bamboo and ECC meets the green building evaluation standards.

[0029] Through the introduction of the inorganic adhesive composite bamboo material and the multi-phase collaborative design of ECC-steel-bamboo, controlled ductile failure is achieved. At the same time, the plug-in groove, docking groove + fastener + adhesive composite connection mechanism and the fully prefabricated assembly process are adopted. The plug-in groove and docking groove are used to release the lateral stress, and the adhesive is used to enhance the interfacial bonding, alleviating the splitting risk, reducing the use of steel and cement-based materials, greatly reducing the self-weight of the joints, achieving the goal of green sustainability. On-site, only component splicing bolt locking and glue injection filling are required for the joint system, greatly reducing on-site steel welding and tying operations, simplifying the construction process, and reducing on-site pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0031] Figure 1 It is a schematic diagram of the prefabricated profiled steel reinforced ECC-inorganic adhesive composite bamboo joint in one or more embodiments of the present invention.

[0032] Figure 2 It is a schematic diagram of the profiled steel column, profiled steel beam and connector in one or more embodiments of the present invention.

[0033] Figure 3 It is a schematic diagram of the prefabricated joint core in one or more embodiments of the present invention.

[0034] Figure 4Schematic diagram of the connection between the connecting member and the profiled steel beam in one or more embodiments of the present invention.

[0035] Among them, 1. Profiled steel ECC column; 2, profiled steel ECC beam; 3. Profiled steel column; 4. Plug-in plate; 5. Profiled steel beam; 6. Connecting member; 7. Fastener; 8. Connecting plate; 9. Web; 10. Inorganic glue composite bamboo beam; 11. Inorganic glue composite bamboo column; 12. Top plate. Detailed implementation manners

[0036] Embodiment 1

[0037] In a typical embodiment of the present invention, as Figures 1 - 4 shown, a prefabricated profiled steel reinforced ECC-inorganic glue composite bamboo joint is provided.

[0038] In the existing joint technology of high ductility cementitious composite material (ECC) combined with profiled steel, its connection method is mainly applicable to steel structures or steel-concrete composite structures, and it is not designed for the anisotropic characteristics of bio-based materials such as bamboo and wood, such as inorganic glue composite bamboo. If an embedded steel plate is used in the inorganic glue composite bamboo material, it cannot be effectively combined with the bamboo fiber matrix, affecting the strength and stress effect, and it is difficult to meet the application requirements of green buildings and high-performance composite structures. Based on this, this embodiment provides a prefabricated profiled steel reinforced ECC-inorganic glue composite bamboo joint, including a profiled steel ECC column 1 and a profiled steel ECC beam 2 connected to the side of the column. The profiled steel ECC column 1 extends out a plug-in plate 4, and the profiled steel ECC beam 2 is fixed with a connecting member 6, which can establish the stress relationship between the joint core area and the inorganic glue composite bamboo beam 10 and the inorganic glue composite bamboo column 11 through plugging, and realizes locking by combining fasteners 7 and adhesive caulking, effectively solving the problem of low connection stiffness. Compared with the traditional bamboo and wood structure beam-column joint connection, it can better transfer the load and improve the overall mechanical performance of the structure; by using the high ductility, strain hardening characteristics and excellent fire resistance of ECC, as well as the high strength and high ductility characteristics of profiled steel, the seismic performance and fire resistance of the joint are comprehensively improved.

[0039] As Figures 1 - 4 shown, the prefabricated profiled steel reinforced ECC-inorganic glue composite bamboo joint mainly includes a profiled steel ECC column 1, a profiled steel ECC beam 2 and a connecting member 6. Among them, the profiled steel ECC column 1 is vertically arranged, and the profiled steel ECC beam 2 is connected to the side of the profiled steel ECC column 1.

[0040] The joint core area is connected to the inorganic glue composite bamboo column 11 vertically. Specifically, cross-shaped plug-in plates 4 extend from both ends of the profiled steel ECC column 1 in the joint area, and are inserted and matched with the cross-shaped plug-in slots opened at the ends of the inorganic glue composite bamboo column 11. Through holes are opened on the plug-in plate 4, and the inorganic glue composite bamboo column 11 is connected by cooperating with fasteners 7, and the gap between the plug-in plate 4 and the plug-in slot is filled with adhesive.

[0041] The node core area is connected to the inorganic glue composite bamboo beam 10 transversely. Specifically, the steel section in the steel ECC beam 2 is in an I-shaped cross-section, which can be an I-beam or an H-beam. One end of the steel ECC beam 2 far from the node core area is connected with a connector 6. The connector 6 includes a top plate 12, a lower flange plate, a connecting plate 8 and a web 9. The lower flange plate, the connecting plate 8 and the web 9 are of an integral structure, and after combination, they form an inverted T-shaped cross-section. Through holes are provided on the top plate 12, the lower flange plate and the web 9. The web 9 is used for inserting the end butt groove in the shape of a straight line of the inorganic glue composite bamboo beam 10. The lower flange plate positions and supports the inorganic glue composite bamboo beam 10, and the top plate 12 fits the upper surfaces of the inorganic glue composite bamboo beam 10 and the steel ECC beam 2.

[0042] In this embodiment, as Figure 2 shown, in order to facilitate the connection with the steel ECC beam 2, the lower flange plate of the connector 6 is provided with a connecting plate 8, and a plate member is arranged on one side of the connecting plate 8 as the web 9. The web 9 and the connecting plate 8 are perpendicular, which is convenient for establishing the insertion fit with the inorganic glue composite bamboo beam 10. There is no web on the other side of the connecting plate 8, which is convenient for fixing with the end of the steel beam 5. During connection, the steel beam 5 can be welded to the connecting plate 8.

[0043] In this embodiment, both the inorganic glue composite bamboo column 11 and the inorganic glue composite bamboo beam 10 are prefabricated components. The inorganic glue composite bamboo column 11 and the inorganic glue composite bamboo beam 10 are prefabricated in the factory, and the material composite is completed by the molding process.

[0044] In this embodiment, the fastener 7 adopts structural forms such as bolts, high-strength bolts, high-strength studs and nuts. The bolts and high-strength bolts mentioned later are all fasteners 7.

[0045] Among them, the adhesive can be an organic glue or an inorganic glue. For working conditions with higher requirements for bonding performance and lower requirements for fire resistance, an organic glue can be used. For working conditions with higher requirements for fire resistance performance, an inorganic glue can be used. The inorganic glue is a high-strength fire-resistant inorganic glue.

[0046] Through the insertion fit of the insertion plate 4, the connector 6 with the inorganic glue composite bamboo column 11 and the inorganic glue composite bamboo beam 10, and combined with the use of the fastener 7 and the adhesive, the problem of low connection stiffness is effectively solved. Compared with the traditional bamboo and wood structure beam-column node connection, it can better transfer the load and improve the overall mechanical performance of the structure. Different from the situation where the beam end is prone to transverse splitting in the traditional structure, in this embodiment, the connection method of the inorganic glue composite bamboo column 11, the inorganic glue composite bamboo beam 10 and the node avoids the transverse splitting failure caused by local stress concentration at the beam end, and prolongs the service life of the structure. Utilizing the high ductility, strain hardening characteristics and excellent fire resistance performance of ECC, as well as the high strength and high ductility characteristics of the steel, the energy dissipation capacity of the node is comprehensively improved. When disasters such as earthquakes occur, it can better absorb and dissipate energy and protect the structural safety.

[0047] By configuring the above connection method, the connection requirements of the anisotropic characteristics of inorganic glue composite bamboo materials can be adapted, solving the problem that the existing ECC steel node technology cannot be effectively combined with inorganic glue composite bamboo, enabling the inorganic glue composite bamboo materials to be better applied in building structures, and promoting the development of green buildings and high-performance composite structures.

[0048] As Figures 2 - 4 shown, the plug-in plate 4 includes a first plate and a second plate that are vertically and cross-distributed. Through holes are respectively formed on the first plate and the second plate, and fasteners 7 are respectively fitted. Moreover, the fasteners 7 fitted with the through holes on the first plate and the fasteners 7 fitted with the through holes on the second plate are vertically oriented in space, and can fasten and connect the inorganic glue composite bamboo column 11 from two mutually perpendicular directions. Due to the anisotropy of bamboo and wood materials, connections in a single direction may become loose or the connection may fail when bearing complex loads. Through the fasteners 7 with a vertically oriented space, the inorganic glue composite bamboo column 11 can be constrained in different directions, effectively resisting loads such as tensile force and shear force from various directions, greatly improving the stability of the connection, further enhancing the connection stiffness of the node, preventing relative displacement or rotation of the node during the stress process, thereby improving the stability of the overall structure, and better solving the problem of low connection stiffness of traditional nodes.

[0049] The fasteners 7 fitted with the through holes on the plug-in plate 4 penetrate through the inorganic glue composite bamboo column 11. The through connection makes the plug-in plate 4 and the inorganic glue composite bamboo column 11 form a tight whole. Compared with non-through connections, the through design can more effectively transfer loads, avoiding damage caused by stress concentration at the connection interface. It ensures that forces can be evenly transferred from the inorganic glue composite bamboo column 11 through the plug-in plate 4 to the core area of the node, reducing local deformation caused by loose connections, thereby further preventing cross-grain splitting damage of the inorganic glue composite bamboo column 11, and at the same time enhancing the energy dissipation capacity of the node. When bearing large loads, the through fasteners 7 can better participate in the energy dissipation mechanism and dissipate energy through their own deformation and friction with the material.

[0050] In this embodiment, as Figure 3 and Figure 4 shown, the fasteners 7 fitted with the through holes on the lower flange plate, the top plate 12 in the connector 6 and the fasteners 7 fitted with the through holes on the web 9 are arranged in a staggered manner. Among them, the fasteners 7 fitted with the lower flange plate and the top plate 12 penetrate through the lower flange plate, the steel ECC beam 2 and the top plate 12 on one side of the connector 6, and penetrate through the lower flange plate, the inorganic glue composite bamboo beam 10 and the top plate 12 on the other side of the connector 6; horizontally, the fasteners 7 fitted with the web 9 penetrate through the inorganic glue composite bamboo beam 10.

[0051] The staggered fasteners 7 can make the inorganic adhesive composite bamboo beam 10 receive the fastening force at different positions, avoiding excessive local stress caused by the fasteners 7 being concentrated at the same position. The different penetration methods of the lower flange plate, the top plate 12 and the web 9 on the connector 6 constrain the inorganic adhesive composite bamboo beam 10 from multiple angles, enhance the connection strength between the steel ECC beam 2 and the inorganic adhesive composite bamboo beam 10, make the connection between the steel ECC beam 2 and the inorganic adhesive composite bamboo beam 10 more stable, can better transfer loads, further improve the connection performance of the node, meet the requirements of the structure under complex stress conditions, and also help to improve the energy dissipation capacity of the node. When subjected to seismic loads, the staggered fasteners 7 can work together from different directions to dissipate energy more effectively.

[0052] The steel ECC column 1 and the steel ECC beam 2 connected to its side constitute the core area of ​​the prefabricated node. The connecting piece 6 is fixed to the steel beam 5 and connected by the fastener 7. Figure 4 As shown, one end of the steel beam 5 away from the core area of ​​the node is fixed to the connecting plate 8 by welding. In order to improve the connection strength, a pre-embedded fastener 7 is also inserted through the bolt hole between the steel beam 5 and the connecting piece 6 for temporary positioning. After the ECC is poured, the pre-embedded fastener 7 passes through the steel ECC beam 2 and is anchored with the bolt hole of the top plate 12 to ensure that the force can be smoothly transmitted from the inorganic adhesive composite bamboo beam 10 to the connecting piece 6, and then to the core area of ​​the prefabricated node.

[0053] The inorganic adhesive composite bamboo beam 10 and the connecting piece 6 are positioned and plugged in. A top plate 12 is fixedly placed on the upper surface of the inorganic adhesive composite bamboo beam 10 to establish a connection with the steel ECC beam 2. The position of the through hole on the top plate 12 corresponds to the steel flange plate inside the steel ECC beam 2 and the lower flange plate of the connecting piece 6. The fasteners 7 pass through the lower flange plate of the connecting piece 6, the inorganic adhesive composite bamboo beam 10, and the through holes on the top plate 12 in turn and are anchored. In addition, a group of fasteners 7 are arranged to pass through the inorganic adhesive composite bamboo beam 10 and the through holes on the web 9 of the connecting piece 6 in a direction perpendicular to the web 9 of the connecting piece 6 and are anchored, thereby completing the staggered connection closure of the steel ECC beam 2 and the inorganic adhesive composite bamboo beam 10.

[0054] The tight connection between the steel ECC beam 2 and the inorganic adhesive composite bamboo beam 10 through the connector 6 increases the integrity and rigidity of the connection, helps to improve the bearing capacity of the entire node, and makes up for the defect of insufficient bearing capacity of traditional inorganic adhesive composite bamboo nodes.

[0055] It should be pointed out that the ECC wrapped around the steel beam 5 is filled in the connection position between the connector 6 and the steel beam 5, and is located between the lower flange plate of the connector 6 and the top plate 12. The good crack control ability of ECC can effectively prevent cracks from appearing at the connection position, improve the durability of the connection, and further ensure the stable performance of the node during long-term use.

[0056] The overall mechanical properties of the joints are enhanced. The synergistic effect between the steel skeleton and the ECC material significantly improves the flexural stiffness, ultimate bearing capacity, and energy dissipation capacity of the joints, forming a "strong column and weak beam" mechanical system, which changes the failure mode from the brittle splitting of traditional bamboo-wood joints to a controllable ductile crushing, ensuring the structural safety.

[0057] Through the "bamboo-glue-steel" collaborative force transmission system, the vertical load is transmitted to the precast joint through the cooperation of the inorganic glue composite bamboo column 11 and the plug-in plate 4 with the plug-in groove. In the lateral load transmission path, the bending moment and shear force are transferred from the inorganic glue composite bamboo beam 10 to the joint core area through the connector 6. After the web 9 of the connector 6 is inserted into the preset docking groove on the inorganic glue composite bamboo beam 10, a multi-path force transmission mechanism is formed through adhesive bonding and fastening with the fastener 7.

[0058] As Figure 2 and Figure 4 shown, the steel column 3 includes a cruciform core column and side plates connected to the core column. The side plates are distributed at intervals along the circumference of the core column. ECC is filled between the side plates and the core column, and the outside of the side plates is wrapped with ECC. The core column and the plug-in plate 4 are of an integral structure. The steel beam 5 is welded and fixed to the side plates, making full use of the high strength of the steel column and the excellent performance of ECC.

[0059] Wrapping the steel column 3 with ECC can make full use of the strain hardening characteristics and fire resistance of ECC, which can effectively prevent the local buckling of the steel column 3, improve the mechanical properties of the steel column 3, and enhance its fire resistance.

[0060] The core column and the plug-in plate 4 are of an integral structure, ensuring that the load transferred from the inorganic glue composite bamboo column 11 can be directly and effectively transmitted to the joint core area, improving the bearing capacity and stability of the joint. When the core column and the plug-in plate 4 are of a split structure, the connection part between them becomes a potential weak point in the entire force transmission path. Under the action of the load, problems such as bolt loosening and weld cracking may occur at the connection part, resulting in unsmooth or interrupted force transmission. In this embodiment, the integral structure eliminates this additional connection, avoids such hidden dangers, and ensures that the load can be stably transmitted from the inorganic glue composite bamboo column 11 through the plug-in plate 4 to the joint core area, thereby enhancing the bearing capacity and stability of the joint.

[0061] As Figure 1 and Figure 4 shown, the steel beam 5 is connected to the side plates. It can evenly transmit the load it bears to the joint core area by virtue of the distribution characteristics of the synergistic force of the side plates, the core column, and ECC. At the same time, the side plates can restrain the deformation of the steel beam 5, optimizing the mechanical properties of the entire joint and solving the deficiencies in force transmission and structural performance of traditional joint designs.

[0062] Embodiment 2

[0063] In another typical embodiment of the present invention, as Figures 1 - 4 shown, a construction method for an assembled steel-reinforced ECC-inorganic glue composite bamboo joint is given.

[0064] The construction method for the assembled steel-reinforced ECC-inorganic glue composite bamboo joint is used for constructing the assembled steel-reinforced ECC-inorganic glue composite bamboo joint as in Example 1, and includes the following steps:

[0065] Weld and fix the steel beam 5 on the side of the steel column 3, and install the connector 6 on the steel beam 5, then pour ECC to form the connected steel ECC column 1 and steel ECC beam 2, constituting the prefabricated joint core area. Open corresponding insertion slots and docking slots on the inorganic glue composite bamboo column 11 and the inorganic glue composite bamboo beam 10, and open holes for the fasteners 7 to pass through;

[0066] Insert the insertion plate 4 at the end of the steel ECC column 1 into the insertion slot at the end of the inorganic glue composite bamboo column 11, inject the adhesive, and lock it by passing the fasteners 7 through the through holes and holes; insert the web 9 at the end of the connector 6 into the docking slot at the end of the inorganic glue composite bamboo beam 10, inject the adhesive, and lock it by passing the fasteners 7 through the through holes and holes.

[0067] Specifically, in combination with Figures 1 - 4 , the construction method for the assembled steel-reinforced ECC-inorganic glue composite bamboo joint is described in detail. In this embodiment, the opened through holes are bolt holes, and the fasteners are bolts and high-strength bolts. Both the inorganic glue composite bamboo beam 10 and the inorganic glue composite bamboo column 11 are prefabricated structures.

[0068] Step S1: The joint core area adopts a steel-reinforced ECC composite structure. Weld the cross-shaped core column combined with the side plate and the I-shaped steel beam 5 to form a skeleton, forming a "strong column and weak beam" mechanical system. Through holes are provided on the upper and lower flanges of the steel beam 5 and the outer insertion plate 4 of the steel column 3; the connector 6 includes a top plate 12, a lower flange plate, a connecting plate 8 and a web 9. The lower flange plate, the connecting plate 8 and the web 9 are an integrated structure, and form an inverted T-shaped cross-section after combination. Through holes are opened on the top plate 12, the lower flange plate and the web 9. The effective heights of the connecting plate 8 and the web 9 of the connector 6 are dynamically designed according to the beam height of the steel ECC beam 2, so as to ensure adaptation to the inorganic glue composite bamboo beams 10 with different cross-sectional dimensions; weld and fix the connector 6 at the end of the steel beam 5, and strictly control the weld position and height during welding to ensure that enough space is reserved in the welding area of the steel beam 5 and the connector 6 to meet the design requirements of the subsequent ECC wrapping layer thickness.

[0069] The embedded bolts only temporarily fix and penetrate through the lower flange plate of the connector 6 and the flange plate of the steel beam 5, and the reserved bolt extension section above the flange plate of the steel beam 5 plays a subsequent positioning and anchoring role.

[0070] Step S2: prefabricate the inorganic adhesive composite bamboo column 11 and the inorganic adhesive composite bamboo beam 10 in the factory, and use a molding process to complete the material composite. According to the design drawings, a vertical prefabricated seam and a bolt hole are opened at the end of the inorganic adhesive composite bamboo column 11, and a transverse prefabricated seam and a bolt hole for high-strength bolts to pass through are opened at the end of the inorganic adhesive composite bamboo beam 10.

[0071] Step S3: Fix the welded steel column 3 and steel beam 5 in the formwork, ensure that the extended steel plate, the position of the embedded bolts and the length of the extended section meet the design and subsequent construction connection requirements, and the extended steel plate is used as the plug-in plate 4. Prepare ECC according to the mix ratio, pour and fill the gap between the core column and the side plate, and cover the steel beam 5, vibrate and compact it, and then maintain it to the design strength.

[0072] Step S4: firstly hoist the end plug-in plate 4 of the steel ECC column 1 into the prefabricated plug-in groove at the end of the inorganic adhesive composite bamboo column 11, inject high-strength fire-resistant adhesive, and then lock it with high-strength bolts. Then, the inorganic adhesive composite bamboo beam 10 is hoisted and aligned so that the web 9 of the connector 6 is inserted into the prefabricated I-shaped docking groove at the end of the inorganic adhesive composite bamboo beam 10, and the adhesive is injected into the groove, and the top plate 12 is tightly attached to the upper surface of the steel ECC beam 2 and the inorganic adhesive composite bamboo beam 10, ensuring that the through holes of the top plate 12 are aligned with the embedded bolts on the steel ECC beam 2 and the reserved through holes of the inorganic adhesive composite bamboo beam 10, tighten the anchor embedded bolts, and then insert high-strength bolts into the remaining through holes of the top plate 12 and the through holes of the inorganic adhesive composite bamboo beam 10, so that the high-strength bolts penetrate the top plate 12, the inorganic adhesive composite bamboo beam 10 and the web 9 of the connector 6, and cooperate with the fastener 7 to fasten in both directions to form an integrated rigid connection of the steel ECC beam 2 and the inorganic adhesive composite bamboo beam 10. Check all bolt connection torques and colloid filling density to ensure the overall assembly accuracy of the node, and ensure the reliability and bearing capacity of the connection.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Assembled steel reinforced ECC-inorganic adhesive composite bamboo node, characterized in that: It includes a steel ECC column and a steel ECC beam connected to its side. Both the steel ECC column and the steel ECC beam are prefabricated components. Cross-shaped plug-in plates extend from both ends of the steel ECC column to plug in the cross-shaped plug-in groove opened at the end of the inorganic adhesive composite bamboo column; a through hole is opened on the plug-in plate; a connector is connected to the end of the steel ECC beam away from the node area, and the connector includes a top plate and an integrated lower flange plate and a web plate. Both the lower flange plate and the top plate are provided with through holes. The web plate is used to plug in the I-shaped docking groove at the end of the inorganic adhesive composite bamboo beam. The lower flange plate supports the matched inorganic adhesive composite bamboo beam, and the top plate fits the inorganic adhesive composite bamboo beam and the top surface of the steel ECC beam; the through hole is connected to the inorganic adhesive composite bamboo column / inorganic adhesive composite bamboo beam through matching fasteners, and adhesive is filled in the gap between the plug-in plate and the plug-in groove, and in the gap between the web plate and the docking groove.

2. The assembled steel reinforced ECC-inorganic adhesive composite bamboo node according to claim 1, characterized in that: The plug board comprises a first board and a second board which are vertically and cross-distributed. Through holes are respectively provided on the first board and the second board, and fasteners are respectively matched therewith.

3. The assembled steel reinforced ECC-inorganic adhesive composite bamboo node according to claim 2, characterized in that: The fasteners matched with the through holes on the first plate and the fasteners matched with the through holes on the second plate are spatially perpendicular.

4. The assembled steel reinforced ECC-inorganic adhesive composite bamboo node according to claim 2 or 3, characterized in that: The fasteners matched with the through holes on the plug-in board penetrate the inorganic glue composite bamboo column.

5. The assembled steel reinforced ECC-inorganic adhesive composite bamboo node according to claim 1, characterized in that: The through holes on the lower flange plate and the top plate correspond to each other and are fixedly connected by fasteners. The fasteners on the lower flange plate and the fasteners on the through holes on the web are staggered. The fasteners that cooperate with the lower flange plate and the top plate penetrate the lower flange plate, the steel ECC beam and the top plate of the connecting part on one side, and penetrate the lower flange plate, the inorganic adhesive composite bamboo beam and the top plate on the other side. The fasteners on the web plate penetrate the inorganic adhesive composite bamboo beam.

6. The assembled steel reinforced ECC-inorganic adhesive composite bamboo node according to claim 1, characterized in that: The steel ECC beam comprises a steel beam and an ECC wrapped outside the steel beam. The connecting piece and the steel beam are welded and fixed and temporarily positioned by embedded fasteners. The fasteners penetrate the lower flange plate of the connecting piece and the top plate of the steel ECC beam and are fastened.

7. The assembled steel reinforced ECC-inorganic adhesive composite bamboo node according to claim 6, characterized in that: The steel beam is in an I-shape, and the ECC is filled in the connection position between the connector and the steel beam, and the ECC is distributed between the lower flange plate and the top plate of the connector.

8. The assembled steel reinforced ECC-inorganic adhesive composite bamboo node according to claim 1, characterized in that: The steel ECC column includes a cross-shaped core column and side panels connected to the core column, the side panels are spaced apart along the circumference of the core column, the space between the side panels and the core column is filled with ECC, the side panels are wrapped with ECC, the core column and the plug-in plate are an integrated structure, and the steel beam is connected to the side panels.

9. A construction method for an assembled steel reinforced ECC-inorganic adhesive composite bamboo node, characterized in that: The fabricated steel reinforced ECC-inorganic adhesive composite bamboo node as described in any one of claims 1 to 8 comprises: Fix the steel beam on the side of the steel column, install the connector on the steel beam and then cast the ECC to form a connected steel ECC column and steel ECC beam, open corresponding plug-in grooves and docking grooves on the inorganic adhesive composite bamboo column and inorganic adhesive composite bamboo beam, and open a channel for fasteners to pass through; The plug-in plate at the end of the steel ECC column is inserted into the plug-in groove at the end of the inorganic adhesive composite bamboo column, and the adhesive is injected, and the fasteners are strung into the through holes and channels for locking; the web at the end of the connector is inserted into the docking groove at the end of the inorganic adhesive composite bamboo beam, and the adhesive is injected, and the fasteners are strung into the through holes and channels for locking.

10. The construction method of the assembled steel reinforced ECC-inorganic adhesive composite bamboo node is characterized in that: The steel ECC column and the steel ECC beam connected to its side constitute the core area of ​​the prefabricated node. The inorganic glue composite bamboo beam is positioned and supported by the lower flange plate of the connecting piece, so that the end of the inorganic glue composite bamboo beam overlaps the lower flange plate of the connecting piece, and cooperates with the top plate to establish a connection between the inorganic glue composite bamboo beam and the core area of ​​the prefabricated node.

Images