Beam-column connection core area construction joint bending-shear-resistant reinforcing joint and construction method

Abstract

The invention discloses a beam-column connection core area construction joint anti-bending and anti-shearing reinforcing joint and a construction method, the beam-column connection core area construction joint anti-bending and anti-shearing reinforcing joint comprises double-layer embedded steel plates arranged between a cast-in-place concrete column and a cast-in-place concrete beam, a damping layer is arranged between the double-layer embedded steel plates, and anti-shearing channel steel is arranged in the middle of each of the two sides of each double-layer embedded steel plate; the shear-resistant channel steel extends into the cast-in-place concrete column or the cast-in-place concrete beam on the side where the shear-resistant channel steel is located. A plurality of penetrating type connecting sleeves are further arranged on the double-layer embedded steel plate, the connecting sleeves are arranged in a manner of being staggered from the shear-resistant channel steel, and the connecting sleeves are connected with bending moment transmission steel bars on the two sides of the double-layer embedded steel plate respectively; a plurality of steel plate anchor bars are further arranged on the face, facing the cast-in-place concrete column, of the double-layer embedded steel plate. According to the beam-column connection core area construction joint bending-shear-resistant reinforcing joint, the problems that a concrete column and concrete beam connection structure is relatively simple, and the shear force transmission performance and durability improvement are poor can be effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of concrete construction, and in particular to a bending and shearing reinforced node for a construction joint in a core area of ​​a beam-column connection and a construction method. Background Art

[0002] In the field of civil engineering, concrete is a widely used engineering composite material. It usually uses cement as a binder, sand and stone as aggregates, and water (which may contain admixtures and additives) mixed in a specific proportion to form cement concrete. When constructing cast-in-place concrete structures, it is often necessary to construct in batches due to the large construction area of ​​a single layer. At this time, construction joints or post-casting strips need to be left. Generally, the construction joints or post-casting strips of concrete beams are placed where the shear force and bending moment of the beam are small, such as 1 / 3 of the span of the beam. However, in the cast-in-place concrete beam-column + steel truss floor deck structural system, due to the limitation that the module of the steel truss floor deck is one span, the construction joints of concrete beams can only be left at the column side where the shear and bending of the beam are large. This makes it very easy for the construction joints to break after the secondary pouring of the beam due to the large shear force and bending moment, which in turn creates serious structural safety hazards.

[0003] Chinese patent publication number CN107489277A discloses a novel steel-concrete beam-column node construction structure and a comprehensive construction method. Before the main structure is constructed, a node three-dimensional model is created using BIM technology, the connection node between the concrete beam and the steel column is deepened, and the BIM data is used for integrated processing of the reinforcement plate. Before on-site construction, the node construction is simulated using BIM technology to determine the optimal solution; the steel column is transported to the construction site for installation, and the column longitudinal reinforcement is fixed vertically on the outside of the steel column through the reinforcement plate, and the beam longitudinal reinforcement and torsion reinforcement are fixed horizontally; and concrete pouring is performed.

[0004] However, during the construction of the above structure, the connection structure between the steel column and the concrete beam is relatively simple, and is poor in shear force transfer performance and durability improvement. Summary of the invention

[0005] The purpose of the present invention is to provide a bending and shear reinforcement node and a construction method for a construction joint in a core area of ​​a beam-column connection in view of the problems existing in the prior art.

[0006] To achieve the above object, the technical solution adopted by the present invention is: A bending and shear reinforcement node for a construction joint in a core area of ​​a beam-column connection, comprising a double-layer embedded steel plate arranged between a cast-in-place concrete column and a cast-in-place concrete beam, a damping layer being arranged between the double-layer embedded steel plates, shear-resistant channel steels being respectively arranged in the middle of both sides of the double-layer embedded steel plate, and the shear-resistant channel steels respectively extending to the cast-in-place concrete column or the cast-in-place concrete beam on the same side; a plurality of through-type connecting sleeves are also arranged on the double-layer embedded steel plate, the connecting sleeves are staggered with the shear-resistant channel steels, and the connecting sleeves are respectively connected to moment transfer steel bars on both sides of the double-layer embedded steel plate; a plurality of steel plate anchor bars are also arranged on the side of the double-layer embedded steel plate facing the cast-in-place concrete column, and the steel plate anchor bars are used to connect the column bars of the cast-in-place concrete column.

[0007] The bending and shear reinforcement node of the construction joint in the core area of ​​the beam-column connection can effectively solve the problem that the connection structure between the concrete column and the concrete beam is relatively simple, and has poor shear force transfer performance and durability improvement through the arrangement of the double-layer embedded steel plate and the shear channel steel and moment transfer steel bars on both sides thereof.

[0008] The double-layer embedded steel plate not only has good strength and stability, but can also be used as a connecting structure to connect other components on both sides. In addition, combined with the damping layer arranged inside, a good collaborative working mechanism is formed to effectively alleviate stress concentration and enhance the overall stability of the structure. The damping layer can play a buffering role and disperse the stress generated by the load. This structure can better adapt to the deformation and stress conditions at the construction joint.

[0009] The shear-resistant channel steel performs excellently in shear force transfer and has improved durability. At the same time, the high-quality moment transfer steel bars and connecting sleeves ensure reliable moment transfer and good connection performance, ensuring the stability and safety of the structure under complex stress conditions from multiple dimensions.

[0010] Furthermore, the double-layer embedded steel plate includes a first steel plate and a second steel plate arranged in parallel, the damping layer is arranged between the first steel plate and the second steel plate, the first steel plate and the second steel plate are provided with a plurality of corresponding through holes to connect the connecting sleeve, and the shear-resistant channel steel is respectively arranged on the outer sides of the first steel plate and the second steel plate.

[0011] Furthermore, the first steel plate and the second steel plate are both rectangular steel plates, the four corners of the rectangular steel plates are respectively provided with arc chamfers, the outer peripheral surfaces of the rectangular steel plates are respectively provided with a number of anchoring teeth, and a number of shear-resistant positioning terminals are also connected between the first steel plate and the second steel plate, which play a role in pre-connection and positioning when the steel plates are spliced.

[0012] Preferably, the first steel plate is a Q355B steel plate with a thickness of 12 to 15 mm, the second steel plate is a high-strength low-alloy steel with a thickness of 6 to 8 mm, and the damping layer is a rubber damping layer with a thickness of 6 to 8 mm.

[0013] Furthermore, the connecting sleeves are symmetrically distributed on the upper and lower sides of the double-layer embedded steel plate. The connecting sleeves are made by a thread rolling forming process and are filled with high-performance structural adhesive. The elongation of the moment transfer steel bars is 12% to 15%, and the surface of the moment transfer steel bars is coated with a 0.15 to 0.2 mm nano-ceramic anti-corrosion coating.

[0014] Preferably, there are at least four steel plate anchor bars, and the ends of the steel plate anchor bars are provided with bending portions bent toward the direction of the double-layer embedded steel plate. The surfaces of the bending portions are provided with a plurality of arc-shaped fitting grooves to increase the contact area with the bar body so as to improve the welding quality.

[0015] Furthermore, the shear-resistant channel steel includes a semicircular upper half and a pair of bottom flat plate sections, the two ends of the semicircular upper half are respectively connected to the pair of bottom flat plate sections in an arc-shaped transition, and a flat plate notch is reserved between the pair of bottom flat plate sections.

[0016] Furthermore, the surface of the shear-resistant channel steel is provided with a fire-proof and anti-corrosion coating, and the inner arc surface of the shear-resistant channel steel is provided with a plurality of shear grooves; the inner periphery of the semicircular upper half is provided with a plurality of freely hanging silk threads, and the ends of the silk threads are connected to the inner wall of the shear-resistant channel steel through a plurality of branch wires.

[0017] A construction method for the bending and shear reinforcement node of the construction joint in the core area of ​​the beam-column connection, the construction method comprises the following steps: According to the general layout and construction drawings, confirm that the construction joint of the cast-in-place concrete beam is located at the position of the cast-in-place concrete column, and calculate the cross-sectional dimensions, concrete strength and expected load parameters of the cast-in-place concrete beam and the cast-in-place concrete column at this position; Based on the statistical load parameters, the reinforcement parts are further designed, including the double-layer embedded steel plates, shear-resistant channel steels, connecting sleeves and moment transfer steel bars, and their models, sizes and layouts are determined; According to the requirements of the in-depth design, the reinforcement is produced, the double-layer embedded steel plate and the steel plate anchor are welded, and then the shear channel steel is welded on the outer surface of the double-layer embedded steel plate, and one end of the moment transfer steel bar is inserted into the connecting sleeve for welding. After completion, the weld appearance quality inspection, ultrasonic inspection and pull-out inspection are carried out; After the reinforcement weld and pull-out test are qualified, positioning is performed, the moment transfer steel bar does not conflict with the reserved main reinforcement position of the cast-in-place concrete beam, and the steel plate anchor bar is welded with the column reinforcement of the cast-in-place concrete column for temporary fixation; Install the formwork and pour concrete for the cast-in-place concrete columns. After removing the formwork of the cast-in-place concrete columns, check the quality of the reinforcement parts, then tie the steel bars of the cast-in-place concrete beams and pour concrete. After the pouring is completed, perform maintenance.

[0018] Furthermore, in the step of deepening the design of the reinforcement, the single-side length of the shear channel steel is not less than 200 mm, the moment transfer steel bar adopts hot-rolled ribbed steel bar with a minimum diameter of not less than 16 mm and a single-side length of not less than 2.5 times the single-side length of the shear channel steel, and the diameter of the shear channel steel is 10 to 15 times the diameter of the moment transfer steel bar.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The bending and shearing reinforcement node of the construction joint in the core area of ​​the beam-column connection can effectively solve the problem that the connection structure between the concrete column and the concrete beam is relatively simple and has poor shear force transmission performance and durability improvement through the arrangement of the double-layer embedded steel plate and the shear-resistant channel steel and the moment transfer steel bars on both sides thereof; 2. The double-layer embedded steel plate not only has good strength and stability itself, but can also be used as a connection structure to connect other components on both sides thereof, and combined with the damping layer arranged therein, a good collaborative working mechanism is formed to effectively alleviate stress concentration and enhance the overall stability of the structure; 3. The damping layer can play a buffering role and disperse the stress generated by the load. This structure can better adapt to the deformation and stress conditions at the construction joint; 4. The shear-resistant channel steel has excellent performance in shear force transmission and improved durability. At the same time, the high-quality moment transfer steel bars and connecting sleeves ensure reliable moment transmission and good connection performance, ensuring the structure in complex from multiple dimensions. Stability and safety under mixed stress conditions; compared with traditional rectangular channels, the shear channel with a semicircular outer surface design has a more uniform stress distribution when subjected to shear force, and the bottom flat plate section below is convenient for connection with other structural members in the beam column, and the arc transition setting can avoid local stress concentration; the setting of the flat plate notch is conducive to the entry of concrete into the shear channel when pouring concrete, which is conducive to the filling of the interior; 5. This method lays a solid foundation for subsequent construction through accurate construction joint position confirmation and comprehensive parameter statistics in the early stage of construction. The in-depth design of the reinforcement ensures that all components work together to efficiently transmit force. In the production stage of the reinforcement, strict quality control and comprehensive testing methods ensure product quality. The precise operation and stabilization measures of the positioning pre-embedded links effectively prevent the displacement and deformation of the reinforcement. During the construction process, attention is paid to the protection of finished products and quality control in each link. The use of non-destructive testing technology further ensures the quality of key parts. The standardized operation and maintenance measures of the overall construction effectively maintain the overall stability and safety performance of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of a bending and shearing reinforced node of a construction joint in a core area of ​​a beam-column connection according to the present invention; Figure 2 It is a structural schematic diagram of the double-layer embedded steel plate of the present invention; Figure 3 For the present invention Figure 2 The enlarged structural diagram at A in the middle; Figure 4 It is a structural schematic diagram of the connection sleeve and the moment transfer steel bar of the present invention; Figure 5 It is a schematic diagram of the cross-sectional structure of the double-layer embedded steel plate of the present invention; Figure 6It is a structural schematic diagram of the steel plate anchor bar of the present invention; Figure 7 It is a structural schematic diagram of the shear-resistant channel steel of the present invention; Figure 8 Another structural schematic diagram of the shear-resistant channel steel of the present invention; Fig. 9 It is a schematic diagram of the method flow of the present invention; In the figure: 1. cast-in-place concrete column; 2. cast-in-place concrete beam; 3. double-layer embedded steel plate; 301. first steel plate; 302. second steel plate; 4. damping layer; 5. anchoring teeth; 6. steel plate anchor bars; 601. bending part; 7. shear channel steel; 701. semicircular upper part; 702. bottom flat plate section; 703. flat plate notch; 8. connecting sleeve; 9. moment transfer steel bar; 10. positioning hole; 11. shear positioning terminal; 12. arc-shaped fitting groove; 13. wire; 14. dividing wire. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "middle", "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0023] like Figure 1 to Figure 3As shown, a bending and shear reinforcement node of the construction joint in the core area of ​​the beam-column connection comprises a double-layer embedded steel plate 3 arranged between a cast-in-place concrete column 1 and a cast-in-place concrete beam 2, a damping layer 4 is arranged between the double-layer embedded steel plates 3, and shear-resistant channel steels 7 are respectively arranged in the middle of both sides of the double-layer embedded steel plates 3, and the shear-resistant channel steels 7 extend to the cast-in-place concrete column 1 or the cast-in-place concrete beam 2 on the same side; a plurality of through-type connecting sleeves 8 are also arranged on the double-layer embedded steel plate 3, and the connecting sleeves 8 are staggered with the shear-resistant channel steels 7, and the connecting sleeves 8 are respectively connected to moment transfer steel bars 9 on both sides of the double-layer embedded steel plate 3; a plurality of steel plate anchor bars 6 are also provided on the side of the double-layer embedded steel plate 3 facing the cast-in-place concrete column 1, and the steel plate anchor bars 6 are used to connect the column bars of the cast-in-place concrete column 1.

[0024] The bending and shear reinforcement node of the construction joint in the core area of ​​the beam-column connection can effectively solve the problem that the connection structure between the concrete column and the concrete beam is relatively simple, and has poor shear force transfer performance and durability improvement through the arrangement of the double-layer embedded steel plate 3 and the shear channel steel 7 and the moment transfer steel bars 9 on both sides thereof.

[0025] The double-layer embedded steel plate 3 not only has good strength and stability, but also can be used as a connecting structure to connect other components on both sides. In addition, combined with the damping layer arranged inside, a good collaborative working mechanism is formed to effectively relieve stress concentration and enhance the overall stability of the structure. The damping layer can play a buffering role and disperse the stress generated by the load. This structure can better adapt to the deformation and stress conditions at the construction joint.

[0026] The shear-resistant channel steel 7 and the moment transfer steel bar 9 can both extend into the cast-in-place concrete column and the cast-in-place concrete beam. The shear-resistant channel steel is the main shear-resistant force-bearing structure, which can effectively transfer and disperse the shear force at the node and has high stability. While the moment transfer steel bar transmits the bending moment, it can also play the role of connecting the double-layer embedded steel plate together with the connecting sleeve.

[0027] The shear-resistant channel steel 7 performs excellently in shear force transmission and has improved durability. At the same time, the high-quality moment transfer steel bars 9 and connecting sleeves 8 ensure reliable moment transmission and good connection performance, ensuring the stability and safety of the structure under complex stress conditions from multiple dimensions.

[0028] The provision of the steel plate anchor bars 6 plays a role of pre-connection and positioning, so that the double-layer embedded steel plates, shear-resistant channel steels and moment transfer steel bars can be installed at the nodes as required, which is beneficial to the overall installation and construction.

[0029] Furthermore, the double-layer embedded steel plate 3 includes a first steel plate 301 and a second steel plate 302 arranged in parallel, the damping layer 4 is arranged between the first steel plate 301 and the second steel plate 302, a plurality of one-to-one corresponding through holes are provided on the first steel plate 301 and the second steel plate 302 to connect the connecting sleeve 8, and the shear-resistant channel steel 7 is respectively arranged on the outer side surfaces of the first steel plate 301 and the second steel plate 302.

[0030] The structures of the first steel plate 301 and the second steel plate 302 are basically the same. Compared with a single steel plate or an integrally formed structure, this structure can better disperse stress and better arrange the damping layer 4, so that the two can have the possibility of force buffering. It is not a completely rigid docking, and the energy dissipation is more obvious.

[0031] Furthermore, the first steel plate 301 and the second steel plate 302 are both rectangular steel plates, the four corners of the rectangular steel plates are respectively provided with arc chamfers, the outer peripheral surfaces of the rectangular steel plates are respectively provided with a plurality of anchoring teeth 5, and a plurality of shear-resistant positioning terminals are also connected between the first steel plate 301 and the second steel plate 302.

[0032] The anchor teeth 5 extend from the circular chamfer of one corner to the circular chamfer of another corner, and the circular chamfers are not provided with these anchor teeth. The circular chamfers at the four corners can avoid stress concentration, and the anchor teeth can greatly optimize the stress distribution. At the same time, the anchor teeth (there are grooves between the teeth) can better connect the concrete, enhance the adhesion of the concrete, and significantly improve the reliability and integrity of the structure.

[0033] like Figure 5 As shown, the shear-resistant positioning terminal 11 is a small strip-shaped terminal with arcs at both ends, which can play a role in positioning and pre-connection, and is conducive to the assembly of the double-layer embedded steel plate 3. A plurality of one-to-one corresponding positioning holes 10 are provided on the first steel plate 301, the second steel plate 302 and the damping layer 4. When assembling the double-layer embedded steel plate, the damping layer is attached to one of the steel plates, such as the first steel plate, so that the positioning holes 10 on the two correspond. One end of the shear-resistant positioning terminal 11 can be inserted into the positioning hole of one of the steel plates, and then the other steel plate is connected. At this time, the double-layer embedded steel plates are temporarily connected together without relative slippage, which is conducive to the further connection of other subsequent components.

[0034] The shear-resistant positioning terminal 11 can be a magnetic terminal with certain magnetism, which can be sucked into the positioning hole and slightly connect the two steel plates. After assembly, the total length of the positioning holes in the two steel plates and the damping layer is longer than the shear-resistant positioning terminal. If there is a buffering situation during subsequent use, the shear-resistant positioning terminal can move inside without causing the damping layer to lose its effect.

[0035] Preferably, the first steel plate is a Q355B steel plate with a thickness of 12 to 15 mm, the second steel plate is a high-strength low-alloy steel with a thickness of 6 to 8 mm, and the damping layer is a rubber damping layer with a thickness of 6 to 8 mm.

[0036] Preferably, the arc chamfer is not a simple chamfer structure, and its distance is one tenth to one eighth of the side length of the double-layer embedded steel plate; the cross-sectional shape of the anchoring tooth is an isosceles triangle, the tooth height is about 5 to 10 mm, and the tooth spacing is 20 to 30 mm. This size design has better connection performance.

[0037] Furthermore, the connecting sleeve 8 is symmetrically distributed on the upper and lower sides of the double-layer embedded steel plate 3. The connecting sleeve 8 is made by a thread rolling forming process and is filled with high-performance structural adhesive, so that the moment transfer steel bar 9 and the connecting sleeve 8 can be more tightly connected, and then they are welded and fixed to further improve their connection strength.

[0038] The elongation of the moment transfer steel bar 9 is 12% to 15%, so that it has a certain deformation capacity and can resist a certain deformation without breaking. In the process of transmitting the bending moment, the maximum stress value of the moment transfer steel bar is less than its yield strength, and the stress transmission at the connection part with the connecting sleeve is good, and there is no obvious stress concentration or connection failure; the surface of the moment transfer steel bar 9 is coated with a 0.15 to 0.2 mm nano-ceramic anti-corrosion coating, which can effectively protect the steel bar from corrosion, thereby improving its durability.

[0039] Preferably, the number of the steel plate anchor bars 6 is at least four, and the ends of the steel plate anchor bars 6 are provided with bending portions 601 bent toward the direction of the double-layer embedded steel plate. Figure 6 As shown, a plurality of arc-shaped fitting grooves 12 are provided on the surface of the bending portion 601 .

[0040] The setting of the bending portion 601 can better connect the column reinforcement in the cast-in-place concrete column, whether it is vertical, horizontal or longitudinal reinforcement; the setting of the arc-shaped fitting groove 12 can accommodate a part of the outer circumference of the reinforcement body, increase the contact area between the steel plate anchor reinforcement and the column reinforcement, and thus increase the welding area, which is convenient for welding, thereby improving the quality and stability of welding and reducing false welding.

[0041] Further, combined with Figure 7 As shown, the shear-resistant channel steel 7 includes a semicircular upper portion 701 and a pair of bottom flat plate sections 702 . The two ends of the semicircular upper portion 701 are respectively connected to the pair of bottom flat plate sections 702 in an arc-shaped transition. A flat plate notch 703 is reserved between the pair of bottom flat plate sections 702 .

[0042] Compared with the traditional rectangular channel steel, the shear channel steel 7 with a semicircular outer surface design has a more uniform stress distribution when subjected to shear force, and the bottom flat plate section 702 below is convenient for connecting with other structural members in the beam column, and the arc transition setting can avoid local stress concentration. The setting of the flat plate notch 703 is conducive to the concrete entering the shear channel steel during pouring concrete, which is conducive to the filling of the interior.

[0043] Furthermore, the surface of the shear-resistant channel steel 7 is provided with a fire-proof and anti-corrosion coating, which can improve its durability; the inner arc surface of the shear-resistant channel steel 7 is provided with a plurality of shear grooves or shear keys, which can effectively transfer the shear force to the surrounding concrete and other components.

[0044] In some embodiments, Figure 8 As shown, the inner periphery of the semicircular upper half 701 is provided with a plurality of freely hanging threads 13, and the ends of the threads 13 are connected to the inner wall of the shear-resistant channel steel 7 through a plurality of branch threads 14. The arrangement of the threads 13 and the branch threads 14 can be melted into the concrete after pouring the concrete, thereby enhancing the strength and stability of the connection with the concrete, and can improve the strength of the concrete around the shear-resistant channel steel, so that it has better stress performance. Such threads and branch threads can form a mesh structure to reduce the occurrence of internal cracks.

[0045] A construction method for strengthening the bending and shearing resistance of the construction joint in the core area of ​​the beam-column connection according to the above-mentioned method, combined with Fig. 9 As shown, the construction method comprises the following steps: Step 1: Confirmation of construction joint position and parameter statistics: According to the general layout plan and construction drawings, confirm that the construction joint of the cast-in-place concrete beam is located at the position of the cast-in-place concrete column, organize technical personnel and construction personnel to conduct on-site inspections, mark factors that may affect the retention of construction joints, such as underground pipelines, adjacent building foundations, etc., and comprehensively count the cross-sectional dimensions, concrete strength and expected load parameters of the cast-in-place concrete beam and the cast-in-place concrete column at this location, so as to provide an accurate basis for subsequent construction.

[0046] Step 2: In-depth design of reinforcements: Based on the statistical load parameters, in-depth design of reinforcements is carried out, and the reinforcements include the double-layer embedded steel plates, shear channel steels, connecting sleeves and moment transfer steel bars, etc., and their models, sizes and layout methods are determined; the single-side length of the shear channel steel is not less than 200mm, and the moment transfer steel bars use hot-rolled ribbed steel bars with a minimum diameter of not less than 16mm, and the single-side length is not less than 2.5 times the single-side length of the shear channel steel, such as not less than 500mm. The diameter of the shear channel steel is 10 to 15 times the diameter of the moment transfer steel bars, such as 100 to 120mm, to ensure that they work together and effectively enhance the bending and shear resistance of the node. Design a variety of schemes for comparative analysis, select the optimal layout method, and ensure that the force transmission path is clear and efficient.

[0047] Step 3: Production and quality inspection of reinforcement parts: Reinforcement parts are produced in accordance with the requirements of the in-depth design, the double-layer embedded steel plate and the steel plate anchor are welded, and then the shear-resistant channel steel is welded on the outer surface of the double-layer embedded steel plate, and one end of the moment transfer steel bar is inserted into the connecting sleeve for welding. After completion, weld appearance quality inspection, ultrasonic inspection and pull-out inspection are carried out; during the welding process, the welding current, voltage and welding speed are strictly controlled to ensure that the weld is full, free of pores and slag inclusions, and to ensure a firm connection; the weld appearance quality inspection is visually inspected by professional quality inspectors in accordance with the requirements of the specifications, and ultrasonic inspection covers all welds. The appearance inspection and ultrasonic inspection shall meet the relevant provisions of the "Steel Structure Welding Code" GB50661~2011. The pull-out inspection of the connecting sleeve 8 (Grade I sleeve) and the moment transfer steel bar 9 is sampled according to a certain proportion, and the inspection equipment is calibrated regularly to ensure that the inspection data is accurate and reliable, and unqualified products are promptly reworked or scrapped.

[0048] Step 4: Positioning and embedding reinforcements: After the reinforcement welds and pull-out tests are qualified, positioning is performed, and the moment transfer reinforcements do not conflict with the reserved main reinforcement positions of the cast-in-place concrete beams, and temporary fixation is performed by welding the steel plate anchor bars to the column bars of the cast-in-place concrete columns; Specifically, before the total station is positioned, the measuring instrument is calibrated and debugged to ensure the measurement accuracy. A high-precision measurement control network is established at the construction site, and the control points are used as the reference for laying out and marking. After the welds of the reinforcements and the steel bar pull-out tests are qualified, the total station is used for precise positioning. During the positioning process, the reinforcements are fixed with auxiliary brackets to keep them stable during the concrete pouring process. At the same time, temporary support points are set on the double-layer embedded steel plates 3 to prevent them from being deformed due to lateral pressure during concrete pouring, ensuring that their position is accurate and does not conflict with the position of the main reinforcement reserved in the beam. Then, the steel plate anchor bars 6 are welded to the column bars for temporary fixation, and a symmetrical welding method is used to reduce welding deformation. After welding is completed, the position of the reinforcements is checked again to ensure that the error is within the allowable range. If there is any deviation, it is adjusted in time.

[0049] Step 5: Column formwork installation and concrete pouring: Install the formwork and pour concrete for the cast-in-place concrete column. After removing the formwork of the cast-in-place concrete column, check the quality of the reinforcement, then tie the steel bars of the cast-in-place concrete beam, pour concrete, and perform maintenance after pouring. Specifically, before installing the column formwork, pre-assemble the formwork, check the flatness of the formwork and the tightness of the joints, trim or replace the formwork that does not meet the requirements, and then install the cast-in-place concrete column 1 formwork. During the installation process, ensure the sealing and stability of the formwork. Before pouring concrete, formulate a detailed pouring plan to clarify the pouring sequence, layer thickness and vibration method. When pouring concrete, pay close attention to the finished product protection of the reinforcement to prevent damage to the reinforcement due to impact, collision and other damages during the concrete pouring process. At the same time, ensure the quality of concrete pouring and ensure the stability of the column structure. When using an inserted vibrator to vibrate the concrete, avoid the vibrating rod touching the reinforcement and formwork to ensure that the concrete is vibrated densely and the surface is smooth.

[0050] Step 6: Quality inspection and subsequent construction: When inspecting the quality of embedded reinforcements, in addition to the conventional position and connection firmness inspection, non-destructive testing technology is also required to conduct internal quality inspections on welds in key locations. Before tying the beam reinforcement, the reinforcement is rust-proofed and straightened, and the reinforcement is arranged according to the spacing and position required by the design to ensure that the intersections of the reinforcement are firmly tied. Before pouring concrete, the beam formwork is sprinkled with water to moisten it to prevent the concrete from losing water and affecting its strength. During the pouring process, concrete test blocks are retained as required to test the concrete strength. Covering and moisturizing maintenance is used for maintenance work. The maintenance time and watering frequency are adjusted according to weather conditions to ensure the normal growth of concrete strength. During the maintenance period, it is strictly forbidden to stack heavy objects on the beam or apply additional loads to ensure structural safety.

[0051] This method lays a solid foundation for subsequent construction by accurately confirming the construction joint position and comprehensively counting parameters in the early stage of construction. The in-depth design of the reinforcement ensures that all components can transmit force in a coordinated and efficient manner. In the production stage of the reinforcement, strict quality control and comprehensive testing methods guarantee product quality. The precise operation and stabilization measures of the positioning and embedding links effectively prevent the displacement and deformation of the reinforcement. During the construction process, attention is paid to the protection of finished products and quality control in each link. The use of non-destructive testing technology further ensures the quality of key parts. The standardized operation and maintenance measures of the overall construction effectively maintain the overall stability and safety performance of the structure.

[0052] By applying a uniform load on the beam , the beam span is set to 8m, and the axial pressure applied to the column top is 1500kN. After calculation, the various components work together, and there is no obvious non-convergence or stress singularity, indicating that the overall structural model is reasonably constructed and the various components can be combined according to the design requirements, proving that the arrangement of the bending and shear strengthening nodes of the construction joints in the core area of ​​the beam-column connection is feasible.

[0053] In the following embodiments, a variety of solutions are compared and analyzed to select the optimal arrangement to ensure that the force transmission path is clear and efficient.

[0054] (1) Parameter selection and verification of double-layer embedded steel plates The material parameters can be set as follows: the outer layer (for example, the first steel plate) of the double-layer embedded steel plate 3 is Q355B with a thickness of 13.5 mm and a yield strength of , elastic modulus , the thickness of the inner layer (such as the second steel plate) high-strength low-alloy steel plate , yield strength of inner steel plate , elastic modulus , the thickness of the rubber damping layer is , assuming that its elastic modulus .

[0055] Result analysis: Under the load set above, the stress distribution of the double-layer embedded steel plate 3 is calculated by finite element software. The calculation results show that the maximum stress value of the outer steel plate is approximately , this value is less than its yield strength The maximum stress value of the inner steel plate is about , which is also less than its assumed yield strength of.

[0056] Furthermore, the above calculation results show that the double-layer embedded steel plate 3 can work normally under load, and the inner and outer steel plates can be synergistically stressed. At the same time, the rubber damping layer can play a buffering role and disperse the stress generated by the load, thereby verifying the double-layer embedded steel plate 3 and the rubber damping layer. This structure can better adapt to the deformation and stress conditions at the construction joint.

[0057] Furthermore, the finite element software mentioned above is an existing technology, which is a numerical analysis technology based on the finite element method. It discretizes complex continuous physical systems into many simple units, and undergoes the main steps of pre-processing (including geometric modeling, meshing, material property definition, boundary condition setting), calculation and solution (using algorithms and solvers to solve unit equations to obtain various physical quantities according to the set problem type), and post-processing (result visualization and data analysis) to approximate the behavior of physical systems. Common software such as ABAQUS, ANSYS, MSCNastran, etc. are widely used in many fields such as aerospace, automobile industry, machinery manufacturing, civil engineering, electronics and electrical appliances, etc., and are powerful engineering analysis tools that help engineers understand the performance of design objects, optimize designs and ensure engineering quality; Its working principle can be simply summarized as follows: divide the complex continuous physical system into many simple units, set material properties, boundary conditions and apply external loads to these units, and then use the corresponding mathematical algorithms and solvers to solve the set of equations composed of the units, calculate the displacement, stress and other physical quantities of each unit, so as to approximately simulate the behavior of the entire physical system under different working conditions.

[0058] See also Figure 2 and Figure 3 The four corners of the double-layer embedded steel plate 3 are arc-shaped, and the distance between them is one tenth to one eighth of the side length of the double-layer embedded steel plate 3. The shape of the anchoring tooth 5 is an isosceles triangle, the tooth height is about 5 to 10 mm, and the tooth spacing is 20 to 30 mm.

[0059] Specifically, the model is refined: based on the established finite element model, the feature that the four corners of the double-layer embedded steel plate 3 are in the shape of arcs (arc chamfers) is accurately simulated. Here, the radius of the arc is taken as one ninth of the side length of the double-layer embedded steel plate 3. At the same time, the isosceles triangle shape of the anchoring tooth 5 is also accurately simulated, and its tooth height is set to , the tooth spacing is .

[0060] Traditional right-angle design: Under the above-set load and boundary conditions, it was calculated by finite element software that when the corners of the double-layer embedded steel plate 3 of the traditional right-angle design were subjected to load, the maximum stress value of the corners reached 300 MPa.

[0061] Arc-shaped corner design: Under the same conditions, the maximum stress value at the corner of the double-layer embedded steel plate 3 with arc-shaped corner design is 240 MPa.

[0062] Result analysis: According to the above, it can be concluded that the maximum stress of the arc-shaped corner is reduced by about 20% compared with the traditional right-angle design. This fully demonstrates that the arc-shaped corner can effectively avoid stress concentration, making the stress distribution of the double-layer embedded steel plate 3 more uniform when bearing load, thereby improving the reliability and stability of the structure, reflecting the advantages of the arc-shaped corner design over the traditional right-angle design in this regard.

[0063] Furthermore, under the above load conditions and boundary conditions, the relative displacement of the steel plate with the anchoring groove 5 in the concrete is calculated by finite element analysis software as follows: Horizontal relative displacement: Near the connection between the beam end and the column, the maximum relative displacement of the steel plate relative to the concrete in the horizontal direction (along the length of the beam) is about 0.15mm; Relative displacement in vertical direction: Near the top of the column, the maximum relative displacement of the steel plate relative to the concrete in the vertical direction (perpendicular to the beam plane) is about 0.2 mm; Under the same load conditions and boundary conditions, the relative displacement of the steel plate without anchor teeth 5 in the concrete is calculated as follows: Horizontal relative displacement: Near the connection between the beam end and the column, the maximum relative displacement of the steel plate relative to the concrete in the horizontal direction is about 0.3 mm, which is about 0.1 mm larger than the above. .

[0064] Vertical relative displacement: Near the top of the column, the maximum relative displacement of the steel plate relative to the concrete in the vertical direction is about 0.45 mm, which is about 0.5 mm larger than the above. .

[0065] Result analysis: The anchor teeth 5 can enhance the bonding force between the steel plate and the concrete. From the displacement calculation results, the relative displacement of the steel plate with the anchor teeth 5 in the concrete is significantly smaller than that of the steel plate without the anchor teeth 5. Therefore, the design of the double-layer embedded steel plate 3 and the anchor teeth 5 helps to improve the integrity and connection performance of the structure.

[0066] (2) Structural analysis, parameter selection and verification of shear channel steel See also Figure 7 The outer surface of the shear-resistant channel steel 7 is semicircular, with a radius of 100-120mm, a wall thickness of 6-8mm, a 50-60mm flat plate section at the end, a shear key on the inner arc surface, and a fire-retardant and anti-corrosion coating on the outer arc surface.

[0067] Specifically, the material parameters are set as follows: the outer surface of the shear channel steel 7 is semicircular, and the radius is , wall thickness is , assuming that its yield strength is , the elastic modulus is , a pair of The bottom plate section.

[0068] Under load, the maximum stress of shear channel steel 7 is calculated by finite element software to be approximately , this value is less than its yield strength Moreover, the shear force can be effectively transferred to the surrounding concrete and other components through the shear keys. Compared with the traditional rectangular channel steel, the shear-resistant channel steel 7 with a semicircular outer surface design has a more uniform stress distribution when subjected to shear force, and the fire-resistant and anti-corrosion coating on the outer arc surface can improve its durability.

[0069] (3) Parameter selection and verification of connection sleeves and moment transfer reinforcement See also Figure 4 The connecting sleeve 8 adopts a thread rolling forming process and is filled with high-performance structural adhesive. The yield strength of the moment transfer steel bar 9 is 420-450MPa and the uniform elongation is 12%-15%. The surface of the moment transfer steel bar 9 is coated with a 0.15-0.2mm nano-ceramic anti-corrosion coating.

[0070] Specifically, the material parameter setting is: the moment transfer reinforcement 9 is assumed to have a yield strength of The uniform elongation is 13.5%. The surface is coated with a nano-ceramic anti-corrosion coating with a thickness of 0.18 mm and an elastic modulus of .

[0071] Result analysis: The calculation results of finite element software show that the maximum stress of the moment transfer steel bar 9 during the moment transfer process is approximately , this value is less than its yield strength The connection part with the connecting sleeve 8 has good stress transmission, and there is no obvious stress concentration or connection failure. The nano-ceramic anti-corrosion coating can effectively protect the steel bars from corrosion, thereby improving their durability. The connecting sleeve 8 of the thread rolling forming process and the high-performance structural adhesive filled in ensure good connection performance.

[0072] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A beam-column connection core area construction joint bending and shear reinforcement node, characterized in that: It comprises a double-layer embedded steel plate arranged between a cast-in-place concrete column and a cast-in-place concrete beam, a damping layer is arranged between the double-layer embedded steel plates, shear-resistant channel steels are respectively arranged in the middle of both sides of the double-layer embedded steel plates, and the shear-resistant channel steels respectively extend to the cast-in-place concrete column or the cast-in-place concrete beam on the side; a plurality of through-type connecting sleeves are also arranged on the double-layer embedded steel plate, the connecting sleeves are staggered with the shear-resistant channel steels, and the connecting sleeves are respectively connected with moment transfer steel bars on both sides of the double-layer embedded steel plate; a plurality of steel plate anchor bars are also arranged on the side of the double-layer embedded steel plate facing the cast-in-place concrete column, and the steel plate anchor bars are used to connect the column bars of the cast-in-place concrete column.

2. The bending and shearing reinforcement node of the construction joint in the core area of ​​the beam-column connection according to claim 1 is characterized in that: The double-layer embedded steel plate includes a first steel plate and a second steel plate arranged in parallel, the damping layer is arranged between the first steel plate and the second steel plate, a plurality of corresponding through holes are provided on the first steel plate and the second steel plate to connect the connecting sleeve, and the shear-resistant channel steel is respectively arranged on the outer sides of the first steel plate and the second steel plate.

3. The bending and shearing reinforcement node of the construction joint in the core area of ​​the beam-column connection according to claim 2 is characterized in that: The first steel plate and the second steel plate are both rectangular steel plates, the four corners of the rectangular steel plates are respectively provided with arc chamfers, the outer peripheral surfaces of the rectangular steel plates are respectively provided with a plurality of anchoring teeth, and a plurality of shear-resistant positioning terminals are also connected between the first steel plate and the second steel plate.

4. The bending and shearing reinforcement node of the construction joint in the core area of ​​the beam-column connection according to claim 2 is characterized in that: The first steel plate is a Q355B steel plate with a thickness of 12 to 15 mm, the second steel plate is a high-strength low-alloy steel with a thickness of 6 to 8 mm, and the damping layer is a rubber damping layer with a thickness of 6 to 8 mm.

5. The bending and shear strengthening node of the construction joint in the core area of ​​the beam-column connection according to claim 1 is characterized in that: The connecting sleeves are symmetrically distributed on the upper and lower sides of the double-layer embedded steel plate. The connecting sleeves are made by a thread rolling forming process and are filled with high-performance structural adhesive. The elongation of the moment transfer steel bars is 12% to 15%, and the surface of the moment transfer steel bars is coated with a 0.15 to 0.2 mm nano-ceramic anti-corrosion coating.

6. The bending and shearing reinforcement node of the construction joint in the core area of ​​the beam-column connection according to claim 1 is characterized in that: There are at least four steel plate anchor bars, and the ends of the steel plate anchor bars are provided with bending portions bent toward the direction of the double-layer embedded steel plate, and the surfaces of the bending portions are provided with a plurality of arc-shaped fitting grooves.

7. The bending and shearing reinforcement node of the construction joint in the core area of ​​the beam-column connection according to claim 1 is characterized in that: The shear-resistant channel steel comprises a semicircular upper half and a pair of bottom flat plate sections. The two ends of the semicircular upper half are respectively connected to the pair of bottom flat plate sections in an arc transition. A flat plate notch is reserved between the pair of bottom flat plate sections.

8. The bending and shearing reinforcement node of the construction joint in the core area of ​​the beam-column connection according to claim 7 is characterized in that: The surface of the shear-resistant channel steel is provided with a fireproof and anti-corrosion coating, and the inner arc surface of the shear-resistant channel steel is provided with a plurality of shear grooves; the inner periphery of the semicircular upper half is provided with a plurality of freely hanging silk threads, and the ends of the silk threads are connected to the inner wall of the shear-resistant channel steel through a plurality of branch wires.

9. A construction method for the bending and shearing reinforced node of the construction joint in the core area of ​​the beam-column connection according to any one of claims 1 to 8, characterized in that: The construction method comprises the following steps: According to the general layout and construction drawings, confirm that the construction joint of the cast-in-place concrete beam is located at the position of the cast-in-place concrete column, and calculate the cross-sectional dimensions, concrete strength and expected load parameters of the cast-in-place concrete beam and the cast-in-place concrete column at this position; Based on the statistical load parameters, the reinforcement parts are further designed, including the double-layer embedded steel plates, shear-resistant channel steels, connecting sleeves and moment transfer steel bars, and their models, sizes and layouts are determined; According to the requirements of the in-depth design, the reinforcement is produced, the double-layer embedded steel plate and the steel plate anchor are welded, and then the shear channel steel is welded on the outer surface of the double-layer embedded steel plate, and one end of the moment transfer steel bar is inserted into the connecting sleeve for welding. After completion, the weld appearance quality inspection, ultrasonic inspection and pull-out inspection are carried out; After the reinforcement weld and pull-out test are qualified, positioning is performed, the moment transfer steel bar does not conflict with the reserved main reinforcement position of the cast-in-place concrete beam, and the steel plate anchor bar is welded with the column reinforcement of the cast-in-place concrete column for temporary fixation; Install the formwork and pour concrete for the cast-in-place concrete columns. After removing the formwork of the cast-in-place concrete columns, check the quality of the reinforcement parts, then tie the steel bars of the cast-in-place concrete beams and pour concrete. After the pouring is completed, perform maintenance.

10. The construction method of the beam-column connection core area construction joint bending and shear strengthening node according to claim 9, characterized in that: In the step of deepening the design of the reinforcement, the single-side length of the shear channel steel is not less than 200 mm, the moment transfer steel bar adopts hot-rolled ribbed steel bar with a minimum diameter of not less than 16 mm and a single-side length of not less than 2.5 times the single-side length of the shear channel steel, and the diameter of the shear channel steel is 10 to 15 times the diameter of the moment transfer steel bar.

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