Shear reinforcement structure for construction joint of concrete beam and construction method thereof

Abstract

The application relates to the technical field of building engineering construction, and discloses a shear-resistant reinforcing structure of a concrete beam construction joint, which comprises a first-poured beam section, a second-poured beam section and a pre-buried shaped steel. A construction joint is formed between the first-poured beam section and the second-poured beam section, the construction joint is located in the span of the concrete beam and is close to the beam end position, the pre-buried shaped steel is arranged across the construction joint, a part of the pre-buried shaped steel is embedded in the first-poured beam section as an anchoring section, and another part of the pre-buried shaped steel extends into the second-poured beam section as an exposed section. The pre-buried shaped steel has a web and flanges, and shear-resistant studs are arranged outside the upper and lower flanges. The shear-resistant reinforcing structure of the construction joint is simple in construction, does not damage the original structure, is reliable in quality, directly transmits force, and is high in shear-resistant efficiency.

Description

Technical Field

[0001] This application relates to the field of building construction technology, and in particular to a shear reinforcement structure for construction joints of concrete beams and its construction method. Background Technology

[0002] In industrial and civil buildings, the construction of concrete beams (especially large-section beams) often cannot leave construction joints in favorable locations such as "1 / 3 span from the beam end" as required by standards and specifications due to site conditions, equipment access, and process coordination. Instead, construction joints are forced to be placed near the beam end where shear force and bending moment are greatest. This practice seriously violates the principles of structural stress and poses a great safety hazard to the structure.

[0003] In the existing technology, the main approaches to addressing this type of problem are as follows: 1. Post-installed shear reinforcement method (abbreviated as: post-installed reinforcement): Shear reinforcement is achieved by post-installing rebar at the construction joint interface. The specific procedure is as follows: At the construction joint interface, based on the calculated required shear capacity, holes are drilled at the end of the original concrete beam (the pre-cast section), and a certain number and diameter of rebars (usually HRB400 grade or higher) are inserted. These rebars are distributed along the beam height, some extending into the pre-cast section and some exposed. Subsequently, the rebars of the post-cast section are tied, and concrete is poured, anchoring the post-installed rebars within the post-cast section to bear the shear force at the construction joint.

[0004] 2. Pre-reserved shear reinforcement method (abbreviated as: pre-reserved reinforcing bars): When pouring the first section of concrete, a certain number of short shear bars (commonly known as "beard bars") are pre-reserved at the construction joint interface. These bars are then wrapped and anchored during the construction of the subsequent section. Specifically, before pouring the first section of concrete, during the rebar tying stage, a certain number and diameter of short rebars are pre-installed at the construction joint interface based on shear capacity calculations. One end of each rebar is anchored within the first section, while the other end extends a certain length beyond the construction joint interface (meeting anchorage requirements). During the construction of the subsequent section, these pre-reserved "beard bars" are encased in the concrete, forming a shear force transmission path. This method avoids the drilling and grouting process required for post-installation rebar, simplifying the construction process.

[0005] Another crude approach is to leave construction joints in unfavorable locations without communicating with the design team on-site, relying solely on the natural bonding of the old and new concrete and the existing stirrups at the interface to bear the shear force. This approach poses a significant safety hazard.

[0006] Those skilled in the art will understand that the above-mentioned prior art has limitations: For post-installed rebar solutions, when the beam cross-section is large and bears heavy loads, the number of shear-resistant post-installed rebars required is enormous. Each rebar needs to undergo multiple processes such as layout, drilling, hole cleaning, adhesive injection, installation, and curing. This not only results in a long construction period and a large workload, but also damages the pre-cast concrete section due to extensive drilling operations, especially in areas with dense rebar, where drilling is difficult and may even damage the original main reinforcement. Furthermore, the quality of rebar installation is affected by factors such as drilling depth, hole cleaning degree, and adhesive injection fullness, making it difficult to guarantee reliability.

[0007] While pre-installed reinforcing bars avoid the drilling process required for post-installation, when shear resistance is extremely high, a large number of short shear bars need to be arranged at the construction joint interface. This may be limited by the beam cross-sectional dimensions (excessive spacing of reinforcing bars affects the quality of concrete pouring), and if there are too many reinforcing bars, a "reinforcing bar cluster" can form at the construction joint interface, potentially affecting the bond quality between the old and new concrete. Furthermore, dispersed reinforcing bars lack the advantage of an "integral" load-bearing member, resulting in relatively low shear resistance. Additionally, to increase overall shear resistance, the interface of the first-poured section often needs to be notched, increasing construction difficulty.

[0008] Therefore, in current engineering practice, there is an urgent need for a shear reinforcement scheme for construction joints of concrete beams that is easy to construct, does not damage the original structure, is reliable in quality, transmits force directly, and has high shear resistance efficiency. Summary of the Invention

[0009] The purpose of this application is to provide a shear reinforcement structure for construction joints of concrete beams. This structure involves arranging pre-embedded steel sections with webs and flanges across the construction joint, with the anchored section embedded in the pre-cast beam section and the exposed section extending into the post-cast beam section. Shear studs are installed on the flanges of the steel sections. This structure utilizes the steel web as a single load-bearing member to directly bear the enormous shear force at the construction joint interface. Combined with the shear studs, it achieves coordinated work between the steel and concrete, effectively replacing the traditional method of distributing force through extensive post-installation of rebar or pre-installed reinforcing bars. This significantly reduces the amount of on-site drilling and rebar installation work, avoids damage to the original structure, and significantly improves the reliability of shear bearing capacity and construction efficiency.

[0010] The embodiments of this application disclose a shear reinforcement structure for construction joints of concrete beams, comprising: Pre-cast concrete beam segments, post-cast concrete beam segments, and embedded steel sections; A construction joint is formed between the pre-cast beam segment and the post-cast beam segment. The construction joint is located within the span of the concrete beam and close to the beam end. The pre-embedded steel section is set across the construction joint. A portion of the pre-embedded steel section is embedded in the pre-cast beam section as an anchoring section, and the other portion of the pre-embedded steel section extends into the post-cast beam section as an exposed section. The embedded steel section has a web and flanges, and shear studs are provided on the outer sides of both the upper and lower flanges of the embedded steel section.

[0011] In another preferred embodiment, additional stirrups are provided on both sides of the pre-embedded steel section, and the additional stirrups are arranged more densely along the length of the beam.

[0012] In another preferred embodiment, the additional stirrups are tied together with the longitudinal reinforcement of the beam.

[0013] In another preferred embodiment, the additional stirrups are arranged continuously along the length of the beam, completely covering the anchorage section and exposed section of the embedded steel.

[0014] In another preferred embodiment, the shear stud is welded to the upper surface of the upper flange and the lower surface of the lower flange of the pre-embedded steel section.

[0015] In another preferred embodiment, the embedded steel section is a hot-rolled H-beam, an I-beam, or a composite steel section welded from steel plates.

[0016] In another preferred embodiment, the web of the embedded steel section is arranged vertically within the concrete beam, and the embedded steel section is centrally arranged along the beam height or offset according to the calculation results of the beam end bending moment and shear force distribution.

[0017] In another preferred embodiment, the embedded steel section is a steel truss, which includes an upper chord, a lower chord, and web members connecting the upper and lower chords. The upper and lower chords are provided with the shear studs.

[0018] In another preferred embodiment, the pre-cast beam segment and the post-cast beam segment are further provided with beam web reinforcement, which is provided on both sides of the concrete beam, in the side area between the upper longitudinal reinforcement and the lower longitudinal reinforcement of the concrete beam.

[0019] The embodiments of this application also disclose a shear reinforcement construction method for construction joints of concrete beams, including the following steps: Select a pre-embedded steel section and install shear studs on the outer sides of the upper and lower flanges of the pre-embedded steel section; The steel reinforcement cage of the pre-cast beam segment is tied, and the pre-embedded steel is positioned according to the design position, so that the anchorage section of the pre-cast steel is located within the range of the pre-cast beam segment, and the exposed section extends to the side of the post-cast beam segment across the construction joint. The concrete of the pre-cast beam segment is poured and vibrated to make it dense, so that the anchoring section of the pre-embedded steel is embedded in the concrete of the pre-cast beam segment, and the exposed section extends out of the construction joint interface. After the concrete of the first-poured beam segment reaches the predetermined strength, the steel reinforcement cage of the subsequent-poured beam segment is tied. The concrete of the post-cast beam segment is poured so that the exposed section of the pre-embedded steel is enclosed in the concrete of the post-cast beam segment.

[0020] The main differences and effects of the implementation method of this application compared with the prior art are as follows: By arranging pre-embedded steel sections with webs and flanges across the construction joint, with the anchoring section embedded in the pre-cast beam section and the exposed section extending into the post-cast beam section, and shear studs installed on the flanges of the steel sections, this structure utilizes the steel web as an integral load-bearing member to directly bear the enormous shear force at the construction joint interface. Combined with the shear studs, this achieves coordinated work between the steel and concrete, effectively replacing the existing method of dispersing force transmission through extensive post-installation of rebar or pre-installed reinforcing bars. This significantly reduces the amount of on-site drilling and rebar installation work, avoids damage to the original structure, and significantly improves the reliability of shear bearing capacity and construction efficiency.

[0021] Furthermore, it abandons the traditional method of relying on dispersed steel bars to transfer shear force by using "post-installed steel bars" or "pre-reserved reinforcing bars". Instead, it adopts pre-embedded steel sections as the main shear-resistant components at the construction joint interface. By utilizing the strong shear resistance of the steel section web, it directly bears the huge shear force at the beam end. The force path is clear and reliable, and the shear resistance efficiency is much higher than that of dispersed steel bars.

[0022] Furthermore, shear studs are installed on the flanges of the pre-embedded steel sections to form a full-interface mechanical anchoring system, ensuring no relative slippage between the steel sections and the concrete and achieving complete collaborative work.

[0023] Furthermore, before pouring the concrete for the first section, the steel sections are pre-embedded in place, which completely avoids the tedious procedures such as drilling and grouting that are required for post-reinforcement. It also overcomes the problem of limited space for the pre-embedded reinforcing bars under extreme loads, achieving "one-time pre-embedding for permanent reinforcement".

[0024] Furthermore, a multi-layered shear defense system is formed through a combination of pre-embedded steel sections, shear studs, and additional stirrups. The studs ensure the coordinated work between the steel section and the concrete, while the additional stirrups restrain the concrete near the steel flange, preventing local crushing failure under enormous pressure.

[0025] Furthermore, for beams with different cross-sections and loads, the shear bearing capacity requirements can be easily met by adjusting the specifications of the steel sections (such as web height and thickness), without having to increase the number of steel bars as much as post-installed reinforcement or pre-installed reinforcing bars. This makes the design simple and construction convenient. Attached Figure Description

[0026] Figure 1 This is a longitudinal elevation sectional view of a concrete beam with a shear reinforcement structure for a construction joint in the first embodiment of this application. Figure 2 yes Figure 1 The cross-sectional view of the shear reinforcement structure of the construction joint of the concrete beam shown. Figure 3This is a flowchart illustrating a method for shear reinforcement of a construction joint in a concrete beam according to the second embodiment of this application.

[0027] Explanation of reference numerals in the attached figures: 1-Pre-cast beam segment, 2-Post-cast beam segment, 3-Construction joint, 4-Embedded steel section, 5-Shear stud, 6-Additional stirrups, 7-Longitudinal reinforcement of beam, 8-Web reinforcement of beam, 9-Frame column. Detailed Implementation

[0028] In the following description, numerous technical details are presented to facilitate the reader's understanding of this application. However, those skilled in the art will understand that the technical solutions claimed in the claims of this application can be implemented even without these technical details and with various variations and modifications based on the following embodiments.

[0029] Explanation of some concepts: Construction joint: An interface reserved during the concrete pouring process for subsequent pouring due to construction organization needs (such as segmented pouring, waiting for material or equipment installation).

[0030] Beam end: refers to the end area where a concrete beam connects to its support (such as a column or wall), and this area usually bears the greatest shear force and bending moment.

[0031] Section steel: refers to steel with a specific cross-sectional shape (such as I-beams, H-beams, and channel steel), which has high shear and bending resistance.

[0032] Steel truss: A lattice-type steel structure component consisting of an upper chord, a lower chord, and web members (diagonal web members and vertical web members). It is characterized by its light weight and high stiffness and is suitable for embedded reinforcement of large-section concrete beams.

[0033] Post-installed rebar: A post-anchoring technique in which holes are drilled in hardened concrete and rebar is anchored into it using structural adhesive.

[0034] Beard reinforcement: Reinforcing bars that extend out of the construction joint interface during the pouring of the first section of concrete. They are then wrapped and anchored during the construction of the subsequent section to bear the interface shear force.

[0035] It should be noted that in this article, the terms "pre-cast segment" and "pre-cast beam segment" refer to the same concept, and "post-cast segment" and "post-cast beam segment" refer to the same concept.

[0036] Additionally, it should be noted that, as used in this article, the term "upper" refers to the side or end further away from the ground, and "lower" refers to the side or end closer to the ground.

[0037] This application aims to provide a pre-embedded steel shear reinforcement structure and its construction method. A section of steel is pre-embedded within the first-cast beam segment on one side of the construction joint, with part of it anchored within the first-cast segment and the other part exposed, to be encased during the construction of the subsequent-cast segment. This steel section, as a monolithic load-bearing component, directly bears the enormous shear force at the construction joint interface, effectively solving the problems of large workload and difficult quality control in traditional post-installation rebar schemes. It also overcomes the shortcomings of pre-reinforced rebar schemes, such as low shear resistance efficiency and limited placement under extreme loads. It is particularly suitable for situations where construction joints are located in unfavorable positions in large-section, heavy-load beams.

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0039] The first embodiment of this application relates to a shear reinforcement structure for construction joints of concrete beams. Figure 1 and Figure 2 This is a structural diagram of the shear reinforcement structure at the construction joint of the concrete beam. Among them, Figure 1 This is a sectional elevation view of the shear reinforcement structure of the construction joint of the concrete beam along the length of the concrete beam. Figure 2 It is along Figure 1 A cross-sectional view of the AA line on the top.

[0040] Specifically, such as Figure 1 and Figure 2 As shown, the shear reinforcement structure of the construction joint of the concrete beam includes: Concrete pre-cast beam segment 1, concrete post-cast beam segment 2, and pre-embedded steel section 4; A pre-cast concrete beam segment 1 and a post-cast concrete beam segment 2 are provided, with a construction joint 3 formed between the pre-cast beam segment 1 and the post-cast beam segment 2. The construction joint 3 is located within the span of the concrete beam and close to the beam end. The pre-embedded steel section 4 is set across the construction joint 3. A part of the pre-embedded steel section 4 is embedded in the pre-cast beam section 1 as an anchoring section, and the other part of the pre-embedded steel section 4 extends into the post-cast beam section 2 as an exposed section. The embedded steel section 4 has a web and flanges, and shear studs 5 are provided on the outer sides of both the upper and lower flanges of the embedded steel section 4.

[0041] Specifically, the shear studs 5 are welded to the upper surface of the upper flange and the lower surface of the lower flange of the pre-embedded steel 4 to enhance the anchoring bond between the steel and the concrete.

[0042] In this embodiment, preferably, additional stirrups 6 are provided on both sides of the pre-embedded steel section 4, and the additional stirrups 6 are arranged more densely along the length of the beam. Furthermore, the additional stirrups 6 are tied and fixed together with the longitudinal reinforcement 7 of the beam.

[0043] Furthermore, preferably, the additional stirrups 6 are arranged continuously along the length of the beam, completely covering the anchorage section and exposed section of the embedded steel 4.

[0044] In this embodiment, preferably, the embedded steel section 4 can be a hot-rolled H-beam, an I-beam, or a composite steel section welded from steel plates.

[0045] Within the concrete beam, the web of the pre-embedded steel section 4 is arranged vertically, and the pre-embedded steel section 4 is centrally arranged along the beam height or offset according to the calculation results of the beam end bending moment and shear force distribution.

[0046] In addition, the pre-embedded steel 4 can also be a steel truss, which includes an upper chord, a lower chord, and web members connecting the upper chord and the lower chord. The upper chord and the lower chord are provided with the shear studs 5.

[0047] Steel truss grids are structural steel components that are lightweight and have high rigidity, making them suitable for embedded reinforcement of large-section concrete beams.

[0048] In other words, in this embodiment, the embedded steel 4 can be a hot-rolled H-beam, I-beam, or other solid-web steel, a welded composite steel, or a steel truss.

[0049] Solid-web steel sections have shear studs 5 welded to the flanges; steel trusses without continuous flange webs have shear studs 5 welded to the upper and lower chords, relying on the upper and lower chords to bond and transfer force with the concrete.

[0050] Specifically, in addition to using finished hot-rolled H-beams, I-beams, and other solid-web steel sections, welded steel plate composite sections can also be used as embedded parts. For example, based on stress calculations, a thick steel plate can be used as the web, with flanges welded to both sides to form a cross-section similar to an H-beam. This approach is suitable for situations requiring special cross-sectional dimensions or where steel procurement is inconvenient; its stress principle and construction method are basically the same as using finished steel sections.

[0051] When concrete beams are very tall (typically over 1.5m, commonly found in high-load areas such as transfer floors and basements), solid-web steel sections may be unsuitable due to their excessive weight, difficulties in processing and transportation, and poor economic efficiency. In such cases, steel trusses can be used as an alternative to solid-web steel sections. A steel truss can consist of an upper chord, a lower chord, and diagonal web members. The diagonal web members are aligned with the principal tensile stress direction, resulting in high shear resistance. As a lattice structure, the steel truss has a significantly lower weight than solid-web steel sections of the same height, facilitating transportation and hoisting. Simultaneously, the amount of steel used is greatly reduced, significantly improving economic efficiency. During construction, the steel truss is pre-embedded at the construction joint location. Shear studs are installed on the truss chords, and additional stirrups are added on both sides. The remaining construction procedures are the same as for steel sections. This solution can be applied to shear reinforcement of construction joints in ultra-high cross-section concrete beams.

[0052] In addition, the pre-cast beam segment 1 and the post-cast beam segment 2 are also provided with beam web reinforcement 8, which is located on both sides of the concrete beam, in the side area between the upper longitudinal reinforcement and the lower longitudinal reinforcement of the concrete beam.

[0053] It should be noted that the web reinforcement of the beam is an inherent structural reinforcement of the concrete beam, independent of the embedded steel and additional stirrups. Its arrangement is determined by the height of the beam section and is not constrained by the position of the embedded steel.

[0054] In summary, this application utilizes pre-embedded steel sections with webs and flanges to span construction joints, with the anchoring section embedded in the pre-cast beam section and the exposed section extending into the post-cast beam section. Shear studs are installed on the flanges of the steel sections. This structure uses the steel web as a monolithic load-bearing member to directly bear the enormous shear force at the construction joint interface. Combined with shear studs, it achieves coordinated work between the steel and concrete, effectively replacing the traditional method of distributing force through extensive post-installation of rebar or pre-installed reinforcing bars. This significantly reduces the amount of on-site drilling and rebar installation work, avoids damage to the original structure, and significantly improves the reliability of shear bearing capacity and construction efficiency.

[0055] To better understand the technical solution of this embodiment, a preferred embodiment will be described below. The details listed in this preferred embodiment are mainly for ease of understanding and are not intended to limit the scope of protection of this application.

[0056] Figure 1 and Figure 2 This is a schematic diagram of a shear reinforcement structure for a construction joint of a concrete beam in this preferred embodiment. First, it should be noted that in this preferred embodiment, the embedded steel section 4 is illustrated using hot-rolled H-beams or I-beams as examples.

[0057] like Figure 1 and Figure 2 As shown, the shear reinforcement structure of the construction joint of the concrete beam mainly includes the following parts: (1) Pre-cast concrete beam segment: The part near the beam end that has been poured.

[0058] (2) Concrete post-cast beam segment: The beam segment constructed later is connected to the pre-cast segment through a construction joint.

[0059] (3) Embedded steel: H-beams or I-beams, whose length spans the construction joint. Part of the steel (anchoring section) is pre-embedded in the pre-cast beam section, and the other part (exposed section) extends into the post-cast beam section area.

[0060] (4) Shear studs: welded to the outer flange and both sides of the web of the embedded steel (if required) to strengthen the anchoring bond between the steel and the concrete and ensure that the shear force can be effectively transmitted. Figure 1 and Figure 2 Only the shear studs welded to the outer edge of the flange are shown in the image.

[0061] (5) Additional stirrups: In the pre-cast and post-cast beam segments, stirrups are densely arranged in the areas on both sides of the steel section to restrain the concrete. Specifically, such as... Figure 1 and Figure 2 As shown, in this preferred embodiment, the web of the embedded steel is arranged in a vertical direction, and additional stirrups are arranged in the areas on both sides of the web of the embedded steel.

[0062] (6) Longitudinal reinforcement of beams: The original longitudinal reinforcing bars of concrete beams are continuously arranged at construction joints or lapped as required.

[0063] In other words, the shear reinforcement structure at the construction joint of the concrete beam includes: a pre-embedded steel section, part of which is anchored in the pre-cast beam section on one side of the construction joint, and the other part extends into the post-cast beam section on the other side of the construction joint; the web of the pre-embedded steel section serves as the main component bearing the shear force at the construction joint interface; shear studs are provided on both the upper and lower flanges of the pre-embedded steel section, and additional stirrups are densely arranged on both sides of the pre-embedded steel section.

[0064] The technical solution of this application has excellent technical effects, specifically: (1) Fundamental change in the force-bearing mechanism: The traditional method of relying on dispersed steel bars to transfer shear force by "post-installed steel bars" or "pre-reserved reinforcing bars" has been abandoned. Instead, pre-embedded steel sections are used as the main shear-resistant components at the construction joint interface. The strong shear resistance of the steel web is utilized to directly bear the huge shear force at the beam end. The force path is clear and reliable, and the shear resistance efficiency is much higher than that of dispersed steel bars.

[0065] (2) Full-interface anchoring system: Shear studs are set on the upper and lower flanges of the pre-embedded steel to form a full-interface mechanical anchoring system, ensuring that there is no relative slippage between the steel and the concrete and achieving complete collaborative work.

[0066] (3) Optimization of construction procedures: The installation of shear reinforcement components is brought forward. Before pouring the concrete of the first section, the steel is pre-embedded in place, which completely avoids the tedious procedures such as drilling and gluing caused by post-installation of reinforcement. It also overcomes the problem of limited space for the arrangement of pre-reserved reinforcement under extreme loads, and realizes "one-time pre-embedding, permanent reinforcement".

[0067] (4) Structural reinforcement: Multiple shear defense lines are formed through the combined design of pre-embedded steel sections, shear studs, and additional stirrups. The studs ensure the coordinated work of the steel sections and concrete, while the additional stirrups restrain the concrete near the flanges of the steel sections, preventing local crushing failure under huge pressure.

[0068] (5) High design flexibility: For beams with different cross sections and loads, the shear bearing capacity requirements can be easily met by adjusting the specifications of the steel section (such as web height and thickness), without having to increase the number of steel bars as much as post-installed reinforcement or pre-reserved reinforcement. The design is simple and the construction is convenient.

[0069] In summary, the technical solution of this application utilizes steel profiles as integral load-bearing components. By adjusting the thickness or height of the steel web, the load-bearing capacity can be linearly increased. It is highly adaptable and has high shear efficiency. For beams with different load levels, only the specifications of the steel profiles need to be adjusted, without changing the construction process. The design is flexible and not limited by the space for reinforcement arrangement, making it particularly suitable for extreme conditions such as ultra-large cross-sections and heavy loads. The mechanical anchorage of the steel profiles (through full-interface shear studs on the flanges) and the encapsulation of concrete are used for load-bearing, avoiding the uncertainty of chemical anchorage. Moreover, the surface of the steel profiles is simple and will not form "reinforcement clusters" that hinder concrete pouring. The quality is highly reliable, the force transmission is stable, and the shear bearing capacity is guaranteed, eliminating safety hazards caused by improper human operation or interface defects. In addition, the steel profiles used (such as H-beams) not only bear shear in the web, but their flanges can also bear part of the bending moment, which also improves the bending performance at construction joints. The overall load-bearing performance is good. While solving the shear problem, it also enhances the bending resistance and integrity of the joints, making it a more comprehensive reinforcement measure.

[0070] It should be noted that the components or devices mentioned in the embodiments of this application are all logical modules. Physically, a logical module can be a physical module, a part of a physical module, or a combination of multiple physical modules. The physical implementation of these logical modules themselves is not the most important factor; rather, the combination of functions implemented by these logical modules is the key to solving the technical problem proposed in this application. Furthermore, to highlight the innovative aspects of this application, the above-described system embodiments have not introduced components or devices that are not closely related to solving the technical problem proposed in this application. This does not mean that other components or devices do not exist in the above embodiments.

[0071] The second embodiment of this application relates to a method for shear reinforcement of construction joints in concrete beams. Figure 3 This is a flowchart illustrating the shear reinforcement construction method for the construction joint of the concrete beam.

[0072] Specifically, such as Figure 3 As shown, the shear reinforcement construction method for the construction joint of the concrete beam includes the following steps: In step 301, a pre-embedded steel section 4 is selected, and shear studs 5 are provided on the outer sides of the upper and lower flanges of the pre-embedded steel section 4.

[0073] Then proceed to step 302, tie the steel reinforcement cage of the pre-cast beam segment 1, and position the pre-embedded steel 4 according to the design position, so that the anchorage section of the pre-cast steel 4 is located within the range of the pre-cast beam segment 1, and the exposed section extends to the side of the post-cast beam segment 2 across the construction joint 3.

[0074] Then proceed to step 303, pour concrete for the pre-cast beam segment 1 and vibrate it to make it compact, so that the anchoring section of the pre-embedded steel 4 is embedded in the concrete of the pre-cast beam segment 1, and the exposed section extends out of the construction joint 3 interface.

[0075] Then proceed to step 304, after the concrete of the first-poured beam segment 1 reaches the predetermined strength, tie the steel reinforcement cage of the second-poured beam segment 2.

[0076] Then proceed to step 305, pour concrete for the post-cast beam segment 2, so that the exposed section of the pre-embedded steel 4 is encased in the concrete of the post-cast beam segment 2.

[0077] This process will then end.

[0078] In this embodiment, preferably, the following steps may be included before step 303: Additional stirrups 6 are provided on both sides of the pre-embedded steel section 4, and the additional stirrups 6 are tied and fixed to the longitudinal reinforcement of the beam.

[0079] To better understand the technical solution of this embodiment, a preferred embodiment will be described below. The details listed in this preferred embodiment are mainly for ease of understanding and are not intended to limit the scope of protection of this application.

[0080] In this preferred embodiment, the specific construction steps of the shear reinforcement construction method for the construction joint of the concrete beam are as follows: Step 1: Preparation of Embedded Parts. Based on the design calculations, select the required steel profile. Weld a certain number of shear studs (if necessary) on the outer side of the steel profile flanges and both sides of the web.

[0081] Step 2: Reinforcement Binding and Steel Embedding in the Pre-cast Section. Reinforcement is bound in the pre-cast beam section area. The prepared embedded steel sections are positioned according to the design, ensuring their anchorage sections are within the pre-cast section area. The position and elevation of the steel sections should be precisely controlled. The steel sections are temporarily fixed to the beam's reinforcement cage.

[0082] Step 3: Install additional stirrups. On both sides of the steel section, additional stirrups are installed in a denser manner according to the design requirements and securely tied to the longitudinal reinforcement of the beam.

[0083] Step 4: Concrete pouring for the pre-cast section. Erect the formwork for the pre-cast section, pour the concrete, and vibrate it to ensure compaction. At this point, the anchoring section of the steel section is poured within the pre-cast section, with its exposed portion extending beyond the construction joint interface.

[0084] Step 5: Construction of the post-cast section. After the concrete of the pre-cast section reaches a certain strength, clean the construction joint interface. Tie the longitudinal reinforcement and additional stirrups of the beam for the post-cast section. At this time, the exposed section of the steel is enclosed within the steel reinforcement cage of the post-cast section.

[0085] Step 6: Concrete pouring for the post-cast section. Erect the formwork for the post-cast section and pour concrete to completely enclose the exposed sections of the embedded steel. Once the concrete reaches its design strength, the construction of the entire beam is complete.

[0086] In other words, before pouring the first section of concrete, the steel sections used for shear reinforcement are pre-embedded in the designed positions. Then, the first section of concrete is poured, embedding the anchoring sections of the steel sections and extending the exposed sections. Finally, when constructing the subsequent beam sections, the exposed sections of the steel sections are encased within the concrete of the subsequent beam sections.

[0087] The first embodiment is a structural embodiment corresponding to this embodiment. The technical details in the first embodiment can be applied to this embodiment, and the technical details in this embodiment can also be applied to the first embodiment.

[0088] It should be noted that in the claims and specification of this patent, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0089] Although this application has been illustrated and described with reference to certain preferred embodiments thereof, those skilled in the art should understand that various changes in form and detail may be made thereto without departing from the spirit and scope of this application.

Claims

1. A shear reinforcement structure for construction joints of concrete beams, characterized in that, include: The pre-cast concrete beam segment (1), the post-cast concrete beam segment (2), and the pre-embedded steel section (4); A construction joint (3) is formed between the pre-cast beam segment (1) and the post-cast beam segment (2), and the construction joint (3) is located within the span of the concrete beam and close to the beam end. The pre-embedded steel section (4) is set across the construction joint (3). A part of the pre-embedded steel section (4) is embedded in the pre-cast beam section (1) as an anchoring section, and the other part of the pre-embedded steel section (4) extends into the post-cast beam section (2) as an exposed section. The embedded steel (4) has a web and flanges, and shear studs (5) are provided on the outer sides of the upper and lower flanges of the embedded steel (4).

2. The shear reinforcement structure for construction joints of concrete beams according to claim 1, characterized in that, Additional stirrups (6) are provided on both sides of the pre-embedded steel section (4), and the additional stirrups (6) are arranged densely along the beam length direction.

3. The shear reinforcement structure for construction joints of concrete beams according to claim 2, characterized in that, The additional stirrups (6) are tied together with the longitudinal reinforcement (7) of the beam.

4. The shear reinforcement structure for construction joints of concrete beams according to claim 2, characterized in that: The additional stirrups (6) are arranged continuously along the length of the beam, completely covering the anchorage section and exposed section of the pre-embedded steel (4).

5. The shear reinforcement structure for construction joints of concrete beams according to claim 1, characterized in that, The shear stud (5) is welded to the upper surface of the upper flange and the lower surface of the lower flange of the pre-embedded steel (4).

6. The shear reinforcement structure for construction joints of concrete beams according to claim 1, characterized in that, The embedded steel (4) is hot-rolled H-beam, I-beam, or composite steel made of steel plates.

7. The shear reinforcement structure for construction joints of concrete beams according to claim 1, characterized in that: In the concrete beam, the web of the embedded steel (4) is set in the vertical direction, and the embedded steel (4) is arranged in the center along the beam height direction or offset according to the calculation results of the beam end bending moment and shear force distribution.

8. The shear reinforcement structure for construction joints of concrete beams according to claim 1, characterized in that, The embedded steel (4) is a steel truss, which includes an upper chord, a lower chord, and web members connecting the upper chord and the lower chord. The upper chord and the lower chord are provided with shear studs (5).

9. The shear reinforcement structure for construction joints of concrete beams according to any one of claims 1-8, characterized in that: The pre-cast beam segment (1) and the post-cast beam segment (2) are also provided with beam web reinforcement (8). The beam web reinforcement (8) is provided on both sides of the concrete beam, in the side area between the upper longitudinal reinforcement and the lower longitudinal reinforcement of the concrete beam.

10. A method for shear reinforcement of construction joints in concrete beams, characterized in that, Includes the following steps: Select a pre-embedded steel section (4) and install shear studs (5) on the outer sides of the upper and lower flanges of the pre-embedded steel section (4); Tie the steel reinforcement cage of the pre-cast beam segment (1), and position the pre-embedded steel (4) according to the design position, so that the anchorage section of the pre-cast steel (4) is located within the range of the pre-cast beam segment (1), and the exposed section extends to the side of the post-cast beam segment (2) across the construction joint (3). The concrete of the pre-cast beam segment (1) is poured and vibrated to make it dense, so that the anchoring section of the pre-embedded steel (4) is embedded in the concrete of the pre-cast beam segment (1), and the exposed section extends out of the construction joint (3) interface. After the concrete of the first-cast beam segment (1) reaches the predetermined strength, the steel reinforcement cage of the second-cast beam segment (2) is tied. The concrete of the post-cast beam segment (2) is poured so that the exposed section of the pre-embedded steel (4) is encased in the concrete of the post-cast beam segment (2).

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