A beam-column connection core area construction joint bending shear strengthening joint and construction method

Abstract

The application discloses a kind of beam-column connecting core area construction joint bending shear strengthening node and construction method, including the double-layer pre-embedded steel plate being arranged between cast-in-place concrete column and cast-in-place concrete beam, the double-layer pre-embedded steel plate between being equipped with damping layer, the two sides of the double-layer pre-embedded steel plate middle part are equipped with shear groove steel respectively, the shear groove steel extends to cast-in-place concrete column or cast-in-place concrete beam in the side respectively;Several through connecting sleeve are further equipped on the double-layer pre-embedded steel plate, the connecting sleeve is staggered the shear groove steel arrangement, the connecting sleeve is respectively connected with bending moment transmission reinforcement on the two sides of the double-layer pre-embedded steel plate;The one side of the double-layer pre-embedded steel plate towards cast-in-place concrete column is further equipped with multiple steel plate anchor bars.This beam-column connecting core area construction joint bending shear strengthening node can effectively solve the problem that concrete column and concrete beam connecting structure are relatively simple, are poor in shear transfer performance and durability improvement.

Description

Technical Field

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

[0002] In civil engineering, concrete, a widely used engineering composite material, is typically made of cement as the binder, sand and stone as aggregates, and water (which may contain admixtures and additives) mixed in specific proportions to create cement concrete. During the construction of cast-in-place concrete structures, due to the large construction area of ​​a single floor, construction often requires batches. This necessitates the creation of construction joints or post-cast strips. Typically, these joints are located where the beam is subject to minimal shear and bending moments, such as mid-span. However, in a cast-in-place concrete beam-column + reinforced truss floor slab system, the reinforced truss floor slab module is limited to one span, so concrete beam construction joints can only be placed near the column edge where the beam is subject to significant shear and bending forces. This makes the construction joints highly susceptible to fracture after the beam is poured a second time due to the high shear and bending moments, creating a serious structural safety hazard.

[0003] Chinese patent publication number CN107489277A discloses a novel steel-concrete beam-column node construction structure and integrated construction method. Before the main structure is constructed, BIM technology is used to create a three-dimensional model of the node, deepen the connection node between the concrete beam and the steel column, and use BIM data for integrated processing of the reinforcement plate. Before on-site construction, BIM technology is used to simulate the node construction and determine the optimal solution. The steel column is transported to the construction site for installation, and the reinforcement plate is used to fix the column longitudinal reinforcement vertically and the beam longitudinal reinforcement and torsion reinforcement horizontally on the outside of the steel column. Concrete pouring is then carried out.

[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 terms of 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 response to the problems existing in the prior art.

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

[0007] A bending and shear reinforcement node for a construction joint in a core area of ​​a beam-column connection 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 being provided between the double-layer embedded steel plates, shear-resistant channel steels being respectively provided in the middle of both sides of the double-layer embedded steel plate, the shear-resistant channel steels respectively extending into the cast-in-place concrete column or cast-in-place concrete beam on the respective sides; a plurality of through-type connecting sleeves are also provided on the double-layer embedded steel plate, the connecting sleeves being staggered with the shear-resistant channel steels, and the connecting sleeves being 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 provided on the side of the double-layer embedded steel plate facing the cast-in-place concrete column, the steel plate anchor bars being used to connect the column bars of the cast-in-place concrete column.

[0008] The bending and shear reinforcement node of the construction joint in the core area of ​​the beam-column connection is effectively solved by the arrangement of the double-layer embedded steel plate and the shear channel steel and bending moment transfer steel bars on both sides thereof, which has 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.

[0009] The double-layer pre-buried steel plate not only possesses excellent strength and stability, but also serves as a connecting structure to other components on either side. Furthermore, combined with the damping layer within, it forms a synergistic mechanism, effectively alleviating stress concentration and enhancing the overall stability of the structure. The damping layer acts as a buffer, dispersing the stress generated by the load. This structure can better adapt to the deformation and stress conditions at the construction joint.

[0010] 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.

[0011] 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 one-to-one corresponding through holes to connect the connecting sleeve, and the outer sides of the first steel plate and the second steel plate are respectively provided with the shear-resistant channel steel.

[0012] 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 of pre-connection and positioning when splicing the steel plates.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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 upper half of the semicircle 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.

[0018] A construction method for the bending and shear reinforcement node of the construction joint in the core area of ​​the beam-column connection according to the above-mentioned method comprises the following steps:

[0019] According to the general layout drawing and the construction drawing, 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;

[0020] Based on the statistical load parameters, the reinforcement parts are further designed, including the double-layer embedded steel plates, shear channel steels, connecting sleeves and moment transfer steel bars, and their models, sizes and layouts are determined;

[0021] According to the requirements of the in-depth design, the reinforcement is produced, the double-layer embedded steel plate and the steel plate anchor bar 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 bending 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;

[0022] After the reinforcement welds and pull-out tests are qualified, positioning is performed, and the moment transfer reinforcement does not conflict with the reserved main reinforcement position of the cast-in-place concrete beam, and temporary fixation is performed by welding the steel plate anchor reinforcement to the column reinforcement of the cast-in-place concrete column;

[0023] 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 reinforcements, then tie the steel bars of the cast-in-place concrete beams and pour the concrete. After pouring, perform maintenance.

[0024] 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.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The bending-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 the bending 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, which effectively relieves stress concentration and enhances 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 channel steel performs excellent in shear force transfer and its durability is improved. At the same time, the high-quality bending moment transfer steel bars and connecting sleeves ensure reliable bending moment transfer and good connection performance, ensuring the structure in complex from multiple dimensions. Stability and safety under mixed stress conditions; compared with traditional rectangular channel steel, the shear channel steel 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-shaped transition setting can avoid local stress concentration; the setting of the flat plate groove is conducive to the entry of concrete into the shear channel steel during 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 the various components work together to transmit force efficiently. 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 of 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

[0026] Figure 1 This is a schematic diagram of the overall structure of a bending and shear reinforcement node for a construction joint in a core area of ​​a beam-column connection according to the present invention;

[0027] Figure 2 This is a schematic structural diagram of the double-layer embedded steel plate of the present invention;

[0028] Figure 3 For the present invention Figure 2 A schematic diagram of the structure enlarged in the middle;

[0029] Figure 4 It is a structural schematic diagram of the connecting sleeve and the moment transfer steel bar of the present invention;

[0030] Figure 5A sectional structure schematic diagram of a double-layer embedded steel plate of the present application;

[0031] Figure 6 A structure schematic diagram of a steel plate anchor of the present application;

[0032] Figure 7 A structure schematic diagram of a shear groove steel of the present application;

[0033] Figure 8 Another structure schematic diagram of a shear groove steel of the present application;

[0034] Figure 9 A method flow schematic diagram of the present application;

[0035] 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 tooth; 6, steel plate anchor; 601, bending part; 7, shear groove steel; 701, semicircular upper half; 702, bottom flat section; 703, flat notch; 8, connecting sleeve; 9, bending moment transmission steel bar; 10, positioning hole; 11, shear positioning terminal; 12, arc-shaped fitting groove; 13, wire; 14, wire division. DETAILED DESCRIPTION

[0036] The technical solutions of the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0037] In the description of the present application, it should be noted that the terms “intermediate”, “upper”, “lower”, “left”, “right”, “inner”, “outer” and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms “first”, “second” and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0038] As Figures 1 to 3As shown, a bending and shear reinforcement node for the construction joint of the core area of ​​the beam-column connection includes a double-layer embedded steel plate 3 arranged between the cast-in-place concrete column 1 and the cast-in-place concrete beam 2, a damping layer 4 is provided between the double-layer embedded steel plate 3, and shear-resistant channel steels 7 are respectively provided in the middle of both sides of the double-layer embedded steel plate 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 provided on the double-layer embedded steel plate 3, and the connecting sleeves 8 are staggered with the shear-resistant channel steels 7. The connecting sleeves 8 are respectively connected to bending 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.

[0039] The bending and shear reinforcement node of the construction joint in the core area of ​​the beam-column connection is effectively solved by the arrangement of the double-layer embedded steel plate 3 and the shear channel steel 7 and the bending moment transfer steel bars 9 on both sides thereof, which has 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.

[0040] The double-layer pre-embedded steel plate 3 not only possesses excellent strength and stability, but also serves as a connecting structure to connect other components on both sides. Furthermore, combined with the damping layer arranged within it, it forms a good synergistic mechanism, effectively alleviating stress concentration and enhancing the overall stability of the structure. The damping layer acts as a buffer, dispersing the stress generated by the load. This structure can better adapt to the deformation and stress conditions at the construction joint.

[0041] The shear-resistant channel steel 7 and the moment transfer steel bar 9 can both be extended into the cast-in-place concrete columns and cast-in-place concrete beams. 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.

[0042] The shear-resistant channel steel 7 performs excellently in shear force transmission and has improved durability. At the same time, the high-quality bending moment transmission steel bars 9 and the connecting sleeves 8 ensure reliable bending moment transmission and good connection performance, ensuring the stability and safety of the structure under complex stress conditions from multiple dimensions.

[0043] The provision of the steel plate anchor bars 6 serves the purpose of pre-connection and positioning, so that the double-layer embedded steel plates, shear channel steels and moment transfer steel bars can be installed at the nodes as required, which is beneficial to the overall installation and construction.

[0044] Further, the double-layer embedded steel plate 3 comprises 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 arranged on the first steel plate 301 and the second steel plate 302 to connect the connecting sleeve 8, and the outer sides of the first steel plate 301 and the second steel plate 302 are respectively provided with the shear-resistant channel steel 7.

[0045] 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, can better arrange the damping layer 4, and can make the two have the possibility of stress buffering, is not a completely rigid butt joint, and the energy dissipation is more obvious.

[0046] Further, the first steel plate 301 and the second steel plate 302 are both rectangular steel plates, the four corners of the rectangular steel plate are respectively provided with a circular arc chamfer, and the outer circumferential surface of the rectangular steel plate is respectively provided with a plurality of anchoring teeth 5, and a plurality of shear-resistant positioning terminals are further connected between the first steel plate 301 and the second steel plate 302.

[0047] The anchoring teeth 5 extend from the circular arc chamfer at one corner to the circular arc chamfer at the other corner, and the circular arc chamfers are not provided with the anchoring teeth. The circular arc chamfers at the four corners can avoid stress concentration, the anchoring teeth can greatly optimize the stress distribution, and the anchoring 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.

[0048] As shown in Figure 5 The shear-resistant positioning terminal 11 is a small strip-shaped terminal with a circular arc at both ends, can play a positioning and pre-connection role, is conducive to the assembly of the double-layer embedded steel plate 3. A plurality of one-to-one corresponding positioning holes 10 are arranged 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, the positioning holes 10 on the two are corresponded, one end of the shear-resistant positioning terminal 11 is 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 plate is temporarily connected together and does not slide relative to each other, which is conducive to the further connection of other parts.

[0049] The shear-resistant positioning terminal 11 can be a magnetic terminal with a certain magnetism, which can be attracted in 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 that of the shear-resistant positioning terminal. In the subsequent use process, if there is a buffering situation, the shear-resistant positioning terminal can move internally without losing the effect of the damping layer.

[0050] 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.

[0051] 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.

[0052] 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. This allows the moment transfer steel bar 9 to be more tightly connected to the connecting sleeve 8, and then it is welded and fixed to further improve its connection strength.

[0053] The elongation of the moment transfer steel bar 9 is 12% to 15%, which gives it 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.

[0054] 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 .

[0055] The setting of the bending portion 601 can better connect the column reinforcement in the cast-in-place concrete column, and can connect vertical, horizontal and longitudinal reinforcements; 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, and facilitate welding, thereby improving the quality and stability of welding and reducing false welding.

[0056] Further, combined Figure 7 As shown, the shear-resistant channel steel 7 includes a semicircular upper half 701 and a pair of bottom flat plate sections 702. The two ends of the semicircular upper half 701 are respectively connected to the pair of bottom flat plate sections 702 in an arc-shaped transition, and a flat plate notch 703 is reserved between the pair of bottom flat plate sections 702.

[0057] Compared to traditional rectangular channels, the semicircular outer surface of the shear channel 7 provides more uniform stress distribution when subjected to shear forces. The lower flat plate section 702 facilitates connection with other structural components within the beam column, and the curved transition prevents localized stress concentration. The flat plate notches 703 facilitate concrete entry into the shear channel during concrete pouring, promoting full filling within the channel.

[0058] 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.

[0059] In some embodiments, as Figure 8 As shown, the inner periphery of the semicircular upper portion 701 is provided with a plurality of freely hanging threads 13. The ends of these threads 13 are connected to the inner wall of the shear channel 7 via a plurality of branch threads 14. These threads 13 and branch threads 14 are integrated into the concrete after pouring, enhancing the strength and stability of the connection with the concrete. This improves the strength of the concrete around the inner periphery of the shear channel and enhances its load-bearing performance. These threads and branch threads form a mesh structure, reducing the occurrence of internal cracks.

[0060] 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 Figure 9 As shown, the construction method includes the following steps:

[0061] Step 1: Confirmation of construction joint location 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 to provide an accurate basis for subsequent construction.

[0062] Step 2: Reinforcing member deepening design: According to the statistical load parameters, the reinforcing member is deepened and designed, including the double-layer embedded steel plate, the shear groove steel, the connecting sleeve and the bending moment transmission steel bar, etc., to determine their types, sizes and arrangement modes; the single-side length of the shear groove steel is not less than 200 mm, the bending moment transmission steel bar adopts hot-rolled ribbed steel bar, the minimum diameter is not less than 16 mm, and the single-side length is not less than 2.5 times of the single-side length of the shear groove steel, such as not less than 500 mm, the diameter of the shear groove steel is 10-15 times of the diameter of the bending moment transmission steel bar, such as 100-120 mm, to ensure the cooperative work and effectively enhance the bending shear capacity of the joint, to design multiple schemes for comparison and analysis, to select the optimal arrangement mode, and to ensure the clear and efficient force transmission path.

[0063] Step 3: Reinforcing member production and quality detection: The reinforcing member is produced according to the deepening design requirements, the double-layer embedded steel plate and the steel plate anchor bar are welded, then the shear groove steel is welded on the outer surface of the double-layer embedded steel plate, and one end of the bending moment transmission steel bar is inserted into the connecting sleeve for welding, after completion, the welding appearance quality detection, ultrasonic detection and pulling detection are carried out; the welding current, voltage and welding speed are strictly controlled during welding to ensure that the welding is full, without pores and slag inclusion, and the connection is firm; the welding appearance quality detection is visually inspected by professional quality inspection personnel according to the specification requirements, the ultrasonic detection covers all welds, the appearance detection and ultrasonic detection should meet the relevant provisions of the Steel Structure Welding Specification GB50661-2011, the pulling detection of the connecting sleeve 8 (grade I sleeve) and the bending moment transmission steel bar 9 is sampled according to a certain proportion, the detection equipment is calibrated regularly to ensure that the detection data is accurate and reliable, and the unqualified products are timely reworked or scrapped.

[0064] Step 4: Reinforcing member positioning and embedding: After the welding and pulling detection of the reinforcing member are qualified, positioning is carried out, the bending moment transmission steel bar does not conflict with the position of the reserved main reinforcement of the cast-in-place concrete beam, and temporary fixation is made through the welding of the steel plate anchor bar and the column reinforcement of the cast-in-place concrete column;

[0065] Specifically, before the total station is positioned, the measuring instrument is calibrated and debugged to ensure measurement accuracy. A high-precision measurement control network is established at the construction site, and the lines are laid out and points are marked based on the control points. After the reinforcement welds and steel bar pull-out tests are qualified, the total station is used for precise positioning. During the positioning process, the reinforcement is fixed with auxiliary brackets to keep it stable during the concrete pouring process. At the same time, temporary support points are set on the double-layer embedded steel plate 3 to prevent it from being deformed due to lateral pressure during concrete pouring, ensuring that its position is accurate and does not conflict with the position of the main reinforcement reserved in the beam. Then, the steel plate anchor reinforcement 6 is welded to the column reinforcement for temporary fixation. A symmetrical welding method is used to reduce welding deformation. After welding is completed, the position of the reinforcement is checked again to ensure that the error is within the allowable range. If there is any deviation, it is adjusted in time.

[0066] 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 for the cast-in-place concrete column, check the quality of the reinforcement. Then, tie the steel bars of the cast-in-place concrete beam and pour the concrete. After pouring, perform maintenance.

[0067] 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 protection of the finished reinforcement to prevent damage to the reinforcement such as impact and collision 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 flat.

[0068] Step 6: Quality Inspection and Subsequent Construction: During the quality inspection of embedded reinforcements, in addition to routine position and connection firmness checks, non-destructive testing technology is also required to conduct internal quality inspections of welds in key areas. Before tying the beam reinforcement, the steel bars are rust-removed and straightened. The steel bars are arranged according to the spacing and position required by the design to ensure that the intersections of the steel bars are firmly tied. Before pouring concrete, the beam formwork is sprinkled with water to moisten it to prevent concrete loss and affect its strength. During the pouring process, concrete test blocks are retained as required for testing the concrete strength. Covering and moisturizing maintenance is adopted for maintenance work. The curing time and watering frequency are adjusted according to weather conditions to ensure the normal growth of concrete strength. During the curing period, it is strictly forbidden to stack heavy objects on the beam or apply additional loads to ensure structural safety.

[0069] 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 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.

[0070] By applying a uniform load on the beam The beam span was set at 8m, and an axial pressure of 1500kN was applied to the column tops. After calculation, the components worked together without significant non-convergence or singular stresses. This demonstrates that the overall structural model was constructed appropriately and that the components could be assembled as designed. This also proves that this arrangement of reinforced flexural and shear joints in the core beam-column connection construction joint is feasible.

[0071] In the following embodiments, a variety of solutions are compared and analyzed to select the optimal arrangement to ensure a clear and efficient force transmission path.

[0072] (1) Parameter selection and verification of double-layer embedded steel plates

[0073] The material parameters can be set as follows: the outer layer of the double-layer embedded steel plate 3 (for example, the first steel plate) 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 , inner steel plate yield strength , elastic modulus , the thickness of the rubber damping layer is , assuming its elastic modulus .

[0074] 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.

[0075] Furthermore, the calculation results above demonstrate that the double-layer pre-embedded steel plate 3 functions properly under load, with the inner and outer steel plates synergistically supporting the load. Simultaneously, the rubber damping layer acts as a buffer, dispersing the stress generated by the load. This validates the double-layer pre-embedded steel plate 3 and the rubber damping layer, demonstrating that this structure can better adapt to the deformation and stress conditions at the construction joint.

[0076] Furthermore, the finite element software mentioned above is an existing technology. It is a numerical analysis technology based on the finite element method. It discretizes complex continuous physical systems into many simple units, and undergoes major steps such as pre-processing (including geometric modeling, meshing, material property definition, and boundary condition setting), computational solution (using algorithms and solvers to solve unit equations to obtain various physical quantities based on the set problem type), and post-processing (result visualization and data analysis) to approximately simulate the behavior of physical systems. Common software such as ABAQUS, ANSYS, and MSCNastran are widely used in many fields such as aerospace, automotive industry, mechanical manufacturing, civil engineering, and electronic appliances. They are powerful engineering analysis tools that help engineers understand the performance of design objects, optimize designs, and ensure project quality.

[0077] 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 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.

[0078] See 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.

[0079] 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 arc-shaped (arc chamfered) 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 .

[0080] Traditional right-angle design: Under the above-mentioned load and boundary conditions, the finite element software calculated that when the corners of the double-layer embedded steel plate 3 of the traditional right-angle design are subjected to load, the maximum stress value at the corners reaches 300 MPa.

[0081] The maximum stress value of the corner part of the double-layer embedded steel plate 3 with the arc-shaped corner design is 240 MPa under the same conditions.

[0082] Result analysis: According to the above, the maximum stress of the arc-shaped corner part is reduced by about 20% compared with the traditional right-angle design, which fully shows that the arc-shaped corner can effectively avoid stress concentration, so that the stress distribution of the double-layer embedded steel plate 3 is more uniform when bearing load, thereby improving the reliability and stability of the structure, which reflects the advantages of the arc-shaped corner design compared with the traditional right-angle design in this regard.

[0083] Further, under the above load conditions and boundary conditions, the relative displacement of the steel plate with anchoring tooth groove 5 in the concrete is calculated by the finite element analysis software as follows:

[0084] Horizontal relative displacement: Near the beam end and column connection part, the maximum relative displacement of the steel plate relative to the concrete in the horizontal direction (along the beam length direction) is about 0.15 mm;

[0085] 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 (perpendicular to the beam plane direction) is about 0.2 mm;

[0086] Similarly, under the above load conditions and boundary conditions, the relative displacement of the steel plate without anchoring tooth 5 in the concrete is calculated as follows:

[0087] Horizontal relative displacement: Near the beam end and column connection part, the maximum relative displacement of the steel plate relative to the concrete in the horizontal direction is about 0.3 mm, which is increased by about .

[0088] 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 increased by about .

[0089] Result analysis: The anchoring tooth 5 can enhance the bonding force between the steel plate and the concrete. From the displacement calculation result, the relative displacement of the steel plate with anchoring tooth 5 in the concrete is obviously smaller than that of the steel plate without anchoring tooth 5, so the design of the double-layer embedded steel plate 3 and the anchoring tooth 5 helps to improve the integrity and connection performance of the structure.

[0090] (2) Analysis, parameter selection and verification of shear groove steel structure

[0091] Referring to Figure 7 , the outer surface of the shear groove steel 7 is semicircular with a radius of 100-120 mm, a wall thickness of 6-8 mm, and a 50-60 mm flat section at the end, and a shear key is provided on the inner arc surface, and a fireproof and anticorrosive coating is applied on the outer arc surface.

[0092] 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 its yield strength is , the elastic modulus is , a pair of The bottom flat section.

[0093] Under load, the maximum stress of shear channel steel 7 is calculated by finite element software and is 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 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.

[0094] (3) Parameter selection and verification of connecting sleeves and moment transfer reinforcement

[0095] See Figure 4 The connecting sleeve 8 adopts the thread rolling forming process and is filled with high-performance structural adhesive. The yield strength of the bending moment transfer steel bar 9 is 420~450MPa and the uniform elongation is 12%~15%. The surface of the bending moment transfer steel bar 9 is coated with 0.15~0.2mm nano-ceramic anti-corrosion coating.

[0096] 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%, and the surface is coated with a nano-ceramic anti-corrosion coating with a thickness of 0.18mm, and the elastic modulus is .

[0097] Result analysis: The calculation results of finite element software show that the maximum stress of the moment transfer steel bar 9 during the process of transferring the bending moment is approximately , this value is less than its yield strength The connection with the connecting sleeve 8 is well-transmitted, with no significant stress concentration or connection failure. The nano-ceramic anti-corrosion coating effectively protects the steel from corrosion, thereby improving its durability. The thread roll-formed connecting sleeve 8 and the high-performance structural adhesive filling ensure excellent connection performance.

[0098] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the 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 provided between the double-layer embedded steel plates, shear-resistant channel steels are respectively provided in the middle of both sides of the double-layer embedded steel plate, and the shear-resistant channel steels respectively extend into the cast-in-place concrete column or cast-in-place concrete beam on the corresponding side; the double-layer embedded steel plate is also provided with a plurality of through-type connecting sleeves, 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; the double-layer embedded steel plate is also provided with a plurality of steel plate anchor bars on the side 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; 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. 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.

2. The beam-column connection core area construction joint bending and shear reinforcement node according to claim 1, 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 one-to-one 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 provided on the outer sides of the first steel plate and the second steel plate.

3. The beam-column connection core area construction joint bending and shear reinforcement node according to claim 2, 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 positioning terminals are also connected between the first steel plate and the second steel plate.

4. The beam-column connection core area construction joint bending and shear reinforcement node according to claim 2, 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 beam-column connection core area construction joint bending and shear reinforcement node according to claim 1, 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 beam-column connection core area construction joint bending and shear reinforcement node according to claim 1, 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. A construction method for a flexural and shear reinforced node of a construction joint in a core area of ​​a beam-column connection according to any one of claims 1 to 6, characterized in that: The construction method comprises the following steps: According to the general layout drawing and the construction drawing, 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 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 bar 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 bending 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 welds and pull-out tests are qualified, positioning is performed, and the moment transfer reinforcement does not conflict with the reserved main reinforcement position of the cast-in-place concrete beam, and temporary fixation is performed by welding the steel plate anchor reinforcement to the column reinforcement of the cast-in-place concrete column; 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 reinforcements, then tie the steel bars of the cast-in-place concrete beams and pour the concrete. After pouring, perform maintenance.

8. The construction method of the beam-column connection core area construction joint bending and shear reinforcement node according to claim 7 is 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.

Images