A concrete box girder groove steel bar mounting device and construction method

Abstract

The application discloses a concrete box girder notch steel bar mounting device and a construction method. The device comprises a protection box which is assembled by a plurality of plate pieces and is used for enclosing a box girder notch and containing a pre-buried steel bar in the protection box; a reserved steel bar hole is formed in a box wall of the protection box and is used for allowing the steel bar to pass through; the position of the reserved steel bar hole corresponds to the position of a cross beam steel bar at the box girder notch; and an extrusion sleeve is used for extruding and connecting the steel bar passing through the reserved steel bar hole and the pre-buried steel bar. The application has the advantages of simple structure, low cost, effective reduction of a chiseling process, avoidance of steel bar pollution, reusability of the protection box, satisfaction of the equal strength reinforcement requirement of the steel bar connection, and significant improvement of construction quality and efficiency.

Description

Technical Field

[0001] This application relates to the field of road and municipal engineering and highway bridge construction technology, and in particular to a device and construction method for installing reinforcing bars in the groove of concrete box girders, which is mainly applicable to the post-tensioning construction of urban viaducts. Background Technology

[0002] With increasingly scarce urban land resources, elevated highways, as an important component of the three-dimensional transportation system, can effectively alleviate ground traffic pressure. Prestressed concrete box girders are widely used in post-tensioning construction due to their advantages such as light weight, high load-bearing capacity, and convenient construction. Post-tensioning requires pre-reserving tensioning slots in the crossbeams of the box girder to accommodate tensioning equipment for tensioning, grouting, and anchoring operations. These slots are typically located in the area of ​​the reinforcing steel bars in the crossbeams. During construction, these reinforcing bars must be cut and prepared in advance. After tensioning and anchoring are completed, the cut reinforcing bars are reconnected to ensure the structural integrity.

[0003] However, existing methods for restoring reinforcing bars in slots present numerous challenges. Firstly, the length and placement of reinforcing bars rely heavily on manual calculations, which are prone to errors, leading to rework, wasted materials, and shortened construction time. Secondly, the traditional construction sequence involves first pouring the box girder concrete, then tensioning and anchoring after the concrete reaches the required strength, followed by chiseling away the high-strength concrete (e.g., C50) at the slot to expose the embedded reinforcing bars. This chiseling process is time-consuming and labor-intensive, and the reinforcing bar surface is easily contaminated by concrete, making cleaning difficult and severely impacting subsequent connection quality and secondary pouring effects. Thirdly, reinforcing bar restoration often employs welding or straight threaded sleeve connections: welding quality is highly dependent on the welder's skill level, and the narrow slot makes double-sided welding difficult, resulting in unstable weld quality; straight threaded connections require pre-rolling the threads, making tightening long reinforcing bars in confined spaces difficult, and even slight deviations can prevent proper alignment and tightening, compromising construction quality.

[0004] Therefore, there is an urgent need for an installation device and construction method that can quickly install and restore steel bars of equal strength, ensure construction quality, simplify the chiseling process, avoid steel bar contamination, provide reliable and efficient connections, and reduce construction difficulty and cost, so as to effectively solve the above problems. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, the purpose of this application is to provide a device and construction method for installing reinforcing bars in the groove of a concrete box girder. This application utilizes a detachable, reusable protective box to enclose the groove of the box girder. Pre-drilled holes for reinforcing bars, corresponding to the positions of the crossbeam reinforcing bars, are made in the box wall. Extrusion sleeves are used to mechanically connect the reinforcing bars, effectively reducing the concrete removal process, lowering construction difficulty, shortening the construction period, and saving construction costs. Furthermore, the use of extrusion sleeves for reinforcing bar connection is simple to operate and ensures consistent strength recovery.

[0006] To achieve the above objectives, the first aspect of this application provides a device for restoring the strength of reinforcing bars in the groove of a concrete box girder, comprising: a protective box, which is detachably assembled from several plates and is used to enclose the groove of the box girder and accommodate the pre-embedded reinforcing bars within the protective box; the protective box has reserved reinforcing bar holes on its wall for the reinforcing bars to pass through, the positions of the reserved reinforcing bar holes corresponding to the positions of the crossbeam reinforcing bars at the groove of the box girder; and a compression sleeve, which is used to compress and connect the reinforcing bars passing through the reserved reinforcing bar holes to the pre-embedded reinforcing bars.

[0007] The protective box is assembled from several detachable plates. In a typical embodiment of this application, the protective box is formed by assembling four steel plates: an upper steel plate, a lower steel plate, a left steel plate, and a right steel plate. The four steel plates are joined end to end to form a hollow rectangular frame structure, which forms a protective cavity inside to accommodate the ends of the embedded reinforcing bars and isolate the concrete. However, this application is not limited to the form of four plates. Any protective box that is assembled from several detachable plates and can protect the box girder slot and accommodate the embedded reinforcing bars falls within the scope of this application.

[0008] Its working principle is as follows: During construction, a protective box is pre-installed at the slot of the box girder. The embedded reinforcing bars are passed through pre-drilled holes in the box wall. When the box girder concrete is poured, the protective box creates a cavity at the slot that is not filled with concrete, protecting the ends of the embedded reinforcing bars that need to be restored later within this cavity, preventing them from being contaminated by concrete. After the concrete reaches its strength and the tensioning and grouting processes are completed, the protective box can be directly removed to expose the clean slot cavity and the ends of the embedded reinforcing bars, eliminating the need for large-scale removal of high-strength concrete. Subsequently, the crossbeam reinforcing bars are passed through the slot and connected to the embedded reinforcing bars using a compression sleeve, achieving a quick and reliable restoration of the reinforcing bars to their equal strength. Therefore, this application, by using a pre-drilled cavity for protection and a compression sleeve connection, fundamentally avoids the problems of difficult removal, reinforcing bar contamination, and difficulties in welding or threading operations found in traditional solutions.

[0009] Furthermore, the protective box is formed by an upper steel plate, a lower steel plate, a left steel plate, and a right steel plate, with adjacent steel plates being detachably connected by bolts; thus, the protective box can be assembled from several steel plates according to the size of the slot on site, and can be reused after disassembly, making it widely applicable and low in cost.

[0010] Furthermore, the upper steel plate, lower steel plate, left steel plate and right steel plate are all provided with reserved bolt holes, and adjacent steel plates are fixedly connected by bolts through the reserved bolt holes, thereby realizing quick assembly and disassembly between the steel plates.

[0011] Furthermore, the reserved rebar holes are opened on the left and right steel plates to correspond to the rebars extending into the slots on both sides of the crossbeam.

[0012] Furthermore, a rubber sealing strip is provided in the reserved rebar hole. The rubber sealing strip covers and wraps the rebar passing through the reserved rebar hole, thereby preventing mortar from flowing into the protective box from the reserved rebar hole and contaminating the rebar during concrete pouring. At the same time, it plays a buffering role and avoids direct contact between the rebar and the steel plate, which could damage the raw materials.

[0013] Furthermore, the rubber sealing strip is made of natural rubber, which is elastic and durable.

[0014] Furthermore, the upper steel plate, lower steel plate, left steel plate, and right steel plate are coated with a release agent on the surface facing the concrete to facilitate the easy disassembly and reuse of the protective box after pouring.

[0015] Furthermore, the extrusion sleeve is made of cold-rolled precision seamless steel pipe, which has high strength to ensure that the extrusion connection meets the requirement of equal strength reinforcement.

[0016] The second aspect of this application provides a construction method for restoring the strength of reinforcing bars in the grooves of concrete box girders, employing the aforementioned device and including the following steps:

[0017] S1. Based on the position of the crossbeam reinforcement at the box girder slot, a corresponding reserved reinforcement hole is machined on the box wall of the protective box, and the embedded reinforcement is passed through the reserved reinforcement hole; when the device used includes a rubber sealing strip, a rubber sealing strip is also installed in the reserved reinforcement hole to wrap the embedded reinforcement.

[0018] S2, the several plates are detachably assembled into a protective box, which is then installed at the slot of the box girder, so that the protective box encloses the slot and the embedded steel bars are located inside the protective box;

[0019] S3, pour the box girder concrete (when a rubber sealing strip is provided, the rubber sealing strip prevents mortar from flowing into the protective box and contaminating the reinforcing steel); after the concrete reaches its strength, disassemble the plate and remove the protective box;

[0020] S4, pass the crossbeam reinforcing bar through the groove and connect it with the pre-embedded reinforcing bar, and use the extrusion sleeve to extrude and connect the two to restore the groove reinforcing bar.

[0021] Furthermore, prior to step S1, the cutting length, quantity, and position of the crossbeam reinforcement at the box girder slot are determined through three-dimensional modeling, and the position of the reserved reinforcement hole is determined accordingly, so that the cutting length of the reinforcement and the position of the reserved hole are clear at a glance and are accurately controllable; and / or, the protective box removed in step S3 is cleaned and reused for the construction of the next box girder slot, realizing the reuse of the protective box.

[0022] This application proposes a device and construction method for installing reinforcing bars in the groove of concrete box girders. All components used are conventional steel, extrusion sleeves, and rubber sealing strips, making the materials readily available, easy to process and install, and minimally increasing costs. The core of this method lies in pre-forming a closed cavity at the groove using a detachable protective box, isolating and protecting the ends of the embedded reinforcing bars. During pouring, the rubber sealing strip effectively seals the pre-reserved holes, preventing mortar seepage. Once the concrete reaches its strength, the box can be directly removed to expose the clean reinforcing bars. This completely eliminates the arduous work of large-area chiseling of high-strength concrete in traditional processes, while ensuring the reinforcing bars remain uncontaminated and meet the requirements for subsequent equal-strength connections.

[0023] Before construction, 3D modeling can be used to accurately determine the length, quantity, and location of pre-drilled holes for the reinforcing bars, enabling precise hole positioning and reinforcing bar detailing. This effectively reduces rework, saves raw materials, and makes it easier to connect the embedded reinforcing bars with the beam reinforcing bars. Mechanical connection is achieved using extrusion sleeves. After extrusion, the sleeve and reinforcing bar form a high-strength interlock. The connection quality is guaranteed by controllable hydraulic pressure, unaffected by the welder's skill level, and reliably meets the principle of equal strength reinforcement. Compared to welding, it reduces waste of reinforcing bars at joints. Compared to straight thread connections, it eliminates the need for thread rolling and sleeve tightening, simplifying operation and eliminating limitations imposed by slot space.

[0024] The extrusion sleeve process is highly adaptable to harsh environments such as rain, snow, and low temperatures. A single connection takes only 1-2 minutes and involves no open flame, welding slag, or noise, significantly improving construction safety and green construction standards. The steel plates of the protective box can be prefabricated according to different slot sizes, and can be reused after disassembly and cleaning, offering good economic efficiency. This solution effectively prevents concrete cracking and leakage at the crossbeam slots, extends the bridge's service life, and improves driving safety and comfort, resulting in significant economic and social benefits. Attached Figure Description

[0025] Figure 1 This is a top view of the installation device of this application;

[0026] Figure 2 This is a front view of the installation device of this application;

[0027] Figure 3 This is a side view of the installation device of this application;

[0028] Figure 4 This is a perspective view of the installation device of this application.

[0029] In the diagram: 1. Upper steel plate; 2. Lower steel plate; 3. Left steel plate; 4. Right steel plate; 5. Extrusion sleeve; 6. Reserved bolt hole; 7. Bolt; 8. Rubber sealing strip; 9. Reserved rebar hole. Detailed Implementation

[0030] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0031] like Figures 1 to 4 As shown, this application provides a device for restoring the strength of reinforcing bars in the groove of a concrete box girder. It mainly includes a protective box assembled from several steel plates and a compression sleeve 5. In this embodiment, the protective box is formed by four steel plates: an upper steel plate 1, a lower steel plate 2, a left steel plate 3, and a right steel plate 4. The four steel plates are detachably connected by bolts 7, forming a protective box body that can accommodate pre-embedded reinforcing bars. The left steel plate 3 and the right steel plate 4 have reserved reinforcing bar holes 9 for the reinforcing bars to pass through. The compression sleeve 5 is used to compress and connect the reinforcing bars passing through the reserved reinforcing bar holes 9 to the pre-embedded reinforcing bars. The entire device constitutes a modular protective box system that can be customized according to the groove size and is detachable and reusable. The components are described in detail below with reference to the accompanying drawings.

[0032] The upper steel plate 1, lower steel plate 2, left steel plate 3, and right steel plate 4 are the steel plates of this application, which together form a protective box. Figure 3 and Figure 4 As shown, the upper steel plate 1, the lower steel plate 2, the left steel plate 3, and the right steel plate 4 constitute the upper, lower, left, and right sides of the protective box, respectively. The four steel plates are connected end to end to form a frame-shaped (or box-shaped) protective box body, which forms a protective cavity inside to accommodate the ends of the pre-embedded steel bars and to isolate the concrete during pouring.

[0033] The steel plates in this application can be customized according to the dimensions of the groove on site and can be reused. That is to say, the dimensions of the steel plates on the top, bottom, left and right sides can be prefabricated according to the groove dimensions of different design drawings, thus making the device widely applicable; before use, only the outermost side of the steel plate (i.e. the surface facing the concrete) needs to be brushed with a release agent so that the protective box can be easily removed, disassembled and reused after pouring.

[0034] Preferably, the upper steel plate 1, lower steel plate 2, left steel plate 3, and right steel plate 4 are made of custom-made Q235B steel plates with a thickness of 6mm. Q235B carbon structural steel is chosen because it is a conventional steel material, widely available, inexpensive, and meets the strength requirements. The 6mm thickness is chosen to balance weight and economy, ensuring the steel plate has sufficient rigidity and strength to withstand the lateral pressure of concrete pouring and allowing for reuse. It should be noted that the above grade and thickness are merely preferred examples; those skilled in the art can also select other grades of carbon structural steel plates and corresponding thicknesses according to the groove size and stress requirements, all of which fall within the scope of this application.

[0035] It should be noted that this embodiment uses four steel plates (top, bottom, left, and right) as the specific implementation of the protective box. However, the protective box of this application is not limited to the form of four steel plates assembled together. Any protective box that is detachably assembled from several plates and can protect the box girder slot and accommodate the embedded reinforcing bars is within the scope of protection of this application. For example, the protective box can also be assembled from more or fewer plates, or it can be enclosed by other connection methods that enable detachable assembly. The method of bolting together four steel plates (top, bottom, left, and right) has the advantages of convenient assembly and disassembly, adaptability to rectangular slots, and ease of reuse, and is the preferred embodiment of this application.

[0036] Bolt 7 and the pre-drilled bolt hole 6 are used to achieve a detachable connection between the steel plates. For example... Figure 1 , Figure 3 and Figure 4 As shown, the upper steel plate 1, lower steel plate 2, left steel plate 3, and right steel plate 4 are all provided with pre-drilled bolt holes 6. Adjacent steel plates are fixedly connected by bolts 7 through the corresponding pre-drilled bolt holes 6. During assembly, align the pre-drilled bolt holes 6 of adjacent steel plates, insert the bolts 7 and tighten them to firmly assemble the four steel plates into a whole protective box; during disassembly, unscrew the bolts 7 to separate and remove each steel plate.

[0037] like Figure 1 As shown, the upper and lower steel plates (i.e., upper steel plate 1 and lower steel plate 2) are fixed to the left and right steel plates by bolt connection, which can effectively fix and quickly disassemble, facilitating construction. The detachable connection method using bolts 7 and pre-drilled bolt holes 6 has the advantages of: firstly, rapid assembly and disassembly, and secondly, allowing the protective box to be completely disassembled, cleaned, and reused after use, avoiding the one-time consumption caused by non-detachable connection methods such as welding. It should be noted that bolt connection is the preferred implementation of detachable connection; those skilled in the art can also use other methods to achieve detachable connection, such as snap-fit ​​or pin connection, all of which fall within the scope of this application.

[0038] Reserved rebar hole 9 is used for pre-embedded rebar and subsequent beam rebar to pass through. For example... Figure 4 As shown, pre-drilled rebar holes 9 are provided on the left steel plate 3 and the right steel plate 4. The positions of the pre-drilled rebar holes 9 correspond to the positions of the crossbeam rebars at the box girder slot, that is, the holes are accurately drilled and positioned on the steel plates according to the actual positions of the crossbeam rebars in the drawings. During installation, the pre-embedded rebars are passed through the pre-drilled rebar holes 9, so that the ends of the pre-embedded rebars extend into the protective cavity inside the protective box; when pouring concrete, the part of the pre-embedded rebars located inside the protective box is not filled or encased by concrete; after the box is removed, the crossbeam rebars can be inserted through the slot and connected to the pre-embedded rebars.

[0039] The reason for placing the pre-reserved rebar holes 9 on the left steel plate 3 and the right steel plate 4 is that the reinforcing bars of the crossbeam are usually arranged along the length of the crossbeam and extend into the groove area from both sides of the crossbeam. Therefore, opening holes on the left and right steel plates of the protective box can correspond one-to-one with the reinforcing bars extending into the crossbeam from both sides. The position of the pre-reserved rebar holes 9 can be adjusted according to the position of the crossbeam reinforcing bars in the drawings, thereby achieving precise construction and saving raw materials.

[0040] Rubber sealing strip 8 is used to seal pre-reserved rebar holes 9 and prevent mortar from contaminating the rebar. For example... Figure 3 As shown, a rubber sealing strip 8 is installed in the reserved rebar hole 9. The rubber sealing strip 8 covers and wraps around the rebar passing through the reserved rebar hole 9. The rubber sealing strip 8 is preferably made of natural rubber, which is elastic and durable. The rubber sealing strip 8 has two functions: First, the rubber sealing strip 8 has elasticity and sealing function, which can effectively prevent mortar from flowing into the protective box from the gap between the reserved rebar hole 9 and the rebar and contaminating the rebar when the box girder concrete is poured; Second, the rubber sealing strip 8 is sandwiched between the rebar and the steel plate, which can play a buffering role and avoid direct contact between the rebar and the steel plate and damage to the original material.

[0041] The extrusion sleeve 5 is used to achieve mechanical connections of equal strength for reinforcing bars. For example... Figure 1 , Figure 3 and Figure 4 As shown, the extrusion sleeve 5 is a single-sleeve design. Preferably, the extrusion sleeve 5 is made of cold-rolled precision seamless steel pipe of material 20# steel. In use, the extrusion sleeve 5 is placed on the reinforcing bars to be connected (i.e., the joint between the end of the beam reinforcing bar passing through the reserved reinforcing bar hole 9 and the end of the embedded reinforcing bar). After the groove is sealed and anchored, the sleeve is directly extruded using a special extrusion device to form a whole with the reinforcing bar, thereby achieving a mechanical connection of the reinforcing bars. It should be noted that the cold-rolled precision seamless steel pipe of material 20# steel is only a preferred example. Those skilled in the art can also choose other cold-rolled precision seamless steel pipes that can meet the strength requirements, all of which are within the scope of this application.

[0042] The mechanism by which the extrusion sleeve 5 achieves equal-strength connections lies in the following: During extrusion, a specialized extrusion device applies controllable hydraulic pressure to the sleeve radially, causing plastic deformation of the sleeve wall and tight engagement with the transverse and longitudinal ribs of the connected reinforcing bars, forming a high-strength mechanical interlocking connection. Compared to traditional welding methods, the connection quality of extrusion connections depends on the controllable extrusion hydraulic pressure, rather than the welder's skill level. This ensures standardized operation, stable quality, and reduces steel waste at welded joints. Compared to traditional straight-threaded sleeve connections, extrusion connections eliminate the need for pre-rolling threads during reinforcing bar layout, reducing the processing time for semi-finished reinforcing bars and preventing gaps at the joints. Furthermore, it is not limited by space; as long as the extrusion equipment can fit, equal-strength connections can be achieved. Field testing and verification have shown that the extrusion sleeve mechanical connection method meets the requirements for Class I joints in standards such as JGJ107-2016, with tensile strength exceeding 1.1 times the standard value of the base material, surpassing the requirements of the "equal strength" reinforcement principle.

[0043] During assembly, the upper steel plate 1, lower steel plate 2, left steel plate 3, and right steel plate 4 are enclosed and fastened into a protective box through the reserved bolt holes 6 and bolts 7; rubber sealing strips 8 are inserted into the reserved rebar holes 9 on the left steel plate 3 and right steel plate 4 for the embedded rebar to pass through and be sealed and wrapped; the extrusion sleeve 5 is used as a supporting part for the subsequent extrusion connection of the rebar.

[0044] Before use, the four steel plates (top, bottom, left, and right) are prefabricated according to the dimensions of the groove on site, and a release agent is applied to the concrete-facing surface of each steel plate. During installation, the embedded reinforcing bars are passed through the pre-drilled reinforcing bar holes 9 on the left steel plate 3 and the right steel plate 4. The four steel plates are then assembled and tightened with bolts 7 to form the protective box body. The protective box is installed at the groove position of the box girder, protecting the groove and ensuring that the ends of the embedded reinforcing bars are located in the protective cavity inside the protective box. The rubber sealing strips 8 installed in the pre-drilled reinforcing bar holes 9 effectively prevent mortar from flowing into the protective box and contaminating the reinforcing bars while fixing them in place.

[0045] This application also proposes a construction method for the installation device for the grooved reinforcement of the concrete box girder as described above, comprising the following steps:

[0046] S0: BIM-based 3D modeling and rebar detailing.

[0047] Before formal construction, preliminary rebar detailing is performed using 3D modeling technology (i.e., BIM rebar detailing technology). Specifically, BIM 3D modeling technology is used to import drawings and create a 3D model of the bridge, making the location and quantity of rebar affecting the tensioning slots immediately clear. This completes the rebar detailing, allowing the rebar cutting length to be exported. Simultaneously, the positions of the reserved rebars can also be determined, thereby identifying the locations of the reserved rebar holes 9 on the left steel plate 3 and right steel plate 4 of the protective box. This allows for precise calculation and determination of the rebar cutting length and installation position, laying the foundation for accurate hole positioning and rebar connection in subsequent construction, effectively reducing rework and saving raw materials.

[0048] S1: Drilling holes in the steel plate, inserting reinforcing bars, and installing sealing strips.

[0049] Based on the position of the crossbeam reinforcement at the box girder slot (combined with the above BIM detailing results), corresponding reserved reinforcement holes 9 are machined on the left steel plate 3 and right steel plate 4 of the protective box to achieve accurate hole positioning; the embedded reinforcement is passed through the reserved reinforcement holes 9 so that the end of the embedded reinforcement extends into the protective box; and a rubber sealing strip 8 is installed in the reserved reinforcement holes 9 to cover and wrap the embedded reinforcement, preparing for sealing and pollution prevention during subsequent pouring.

[0050] S2: Assemble the protective box and install it in the slot.

[0051] The upper steel plate 1, lower steel plate 2, left steel plate 3, and right steel plate 4 are detachably assembled into a protective box via pre-drilled bolt holes 6 and bolts 7. This protective box is then installed at the slot opening of the box girder, enclosing the slot and placing the embedded reinforcing bars within it. The upper and lower steel plates are connected by bolts, ensuring effective fixation and facilitating quick disassembly.

[0052] S3: Pouring concrete and unpacking.

[0053] During the pouring process, the rubber sealing strip 8 installed in the reserved rebar hole 9, with its elasticity and sealing effect, prevents mortar from flowing into the protective box from the reserved rebar hole 9 and contaminating the rebar, thus ensuring the cleanliness of the protective cavity inside the protective box and the cleanliness of the ends of the embedded rebar. After the concrete reaches its strength and the relevant tensioning, grouting, and anchoring processes are completed, the bolts 7 are removed, and the upper steel plate 1, lower steel plate 2, left steel plate 3, and right steel plate 4 are taken off, allowing the protective box to be removed as a whole. Since the surface of each steel plate facing the concrete is pre-coated with a release agent, the protective box can be easily removed. After removing the box, a clean protective cavity and the ends of the embedded rebar that are not contaminated by concrete are exposed at the groove, eliminating the need for large-scale chiseling of the high-strength concrete.

[0054] S4: Strong connection such as extrusion sleeve.

[0055] After the tensioning, grouting, and anchoring processes of the groove are completed, the crossbeam reinforcement is passed through the groove and connected to the pre-embedded reinforcement. Five extrusion sleeves are placed at the rebar connection point, and a specialized extrusion device is used to directly compress the sleeves, forming a unified structure between the rebar and the sleeves, thus restoring the groove reinforcement. Field testing and verification have shown that this extrusion sleeve connection method meets the Class I joint requirements of the specifications, with a strength exceeding 1.1 times the strength of the parent material, satisfying the specification requirements for "equal strength" reinforcement restoration. The second pouring of the groove can then proceed.

[0056] S5: Cleaning and reuse of the protective box.

[0057] The removed protective boxes (upper steel plate 1, lower steel plate 2, left steel plate 3, right steel plate 4, and bolts 7) can be cleaned and reused for the construction of the next box girder slot. This repeated use of the protective boxes significantly reduces material amortization costs, minimizes resource waste, and improves the economic efficiency and environmental friendliness of the construction process.

[0058] In the above embodiments, the protective box is preferably assembled from four steel plates (top, bottom, left, and right) using bolts 7. However, this application is not limited to this. Any protective box assembled from several detachable plates that can enclose the box girder slot and accommodate the embedded reinforcing bars is within the scope of this application. The grade and thickness of the steel plates are not limited to Q235B and 6mm; other carbon structural steel plates and corresponding thicknesses can be selected according to actual needs. The detachable connection between adjacent plates is not limited to bolt connections; other detachable connection methods such as snap-fit ​​and pin connections can also be used. The reserved reinforcing bar holes 9 are not limited to being opened on the left and right side steel plates; they can be opened on the corresponding box wall according to the actual position of the crossbeam reinforcing bars. The rubber sealing strip 8 is not limited to natural rubber; any rubber material with elasticity and sealing function is acceptable. The material of the extrusion sleeve 5 is not limited to 20# steel cold-rolled precision seamless steel pipe; any sleeve that can meet the requirements of equal strength connection is acceptable. All the above-mentioned substitution methods are within the protection scope of this application.

[0059] This application proposes a device and construction method for installing reinforcing bars in the groove of a concrete box girder. A detachable protective box forms a closed cavity in the groove. During pouring, a rubber sealing strip prevents grouting. Once the concrete reaches its strength, the box can be directly removed to expose the clean reinforcing bars, completely eliminating the need for traditional large-area chiseling. Precise positioning using 3D modeling reduces rework. The extrusion sleeve connection quality is hydraulically controlled, making operation simple, unrestricted by space, and meeting equal-strength reinforcement requirements. It is also flameless, pollution-free, and highly efficient and safe. The protective box is reusable, offering good economic benefits. Furthermore, by avoiding disturbance and contamination of the parent material from large-area chiseling, the integrity and density of the concrete at the groove are effectively guaranteed, reducing the risk of cracks and leakage after secondary pouring, significantly extending the service life of the bridge structure, and improving driving safety and comfort.

[0060] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A device for installing reinforcing bars in the groove of a concrete box girder, characterized in that, include: A protective box, which is assembled from several detachable plates, is used to protect the groove of the box girder and to house the embedded steel bars inside the protective box. The protective box has reserved steel bar holes on its wall for steel bars to pass through, and the position of the reserved steel bar holes corresponds to the position of the crossbeam steel bars at the box girder slot; and a compression sleeve is used to compress and connect the steel bars passing through the reserved steel bar holes to the pre-embedded steel bars.

2. The installation device according to claim 1, characterized in that, The protective box is formed by an upper steel plate, a lower steel plate, a left steel plate, and a right steel plate, and adjacent steel plates are detachably connected by bolts.

3. The installation device according to claim 2, characterized in that, The upper, lower, left, and right steel plates are all provided with reserved bolt holes, and adjacent steel plates are fixedly connected by bolts through the reserved bolt holes.

4. The installation device according to claim 2 or 3, characterized in that, The reserved rebar holes are opened on the left and right steel plates.

5. The installation device according to claim 1, characterized in that, A rubber sealing strip is provided in the reserved rebar hole, and the rubber sealing strip is sleeved and wrapped around the rebar passing through the reserved rebar hole.

6. The installation device according to claim 5, characterized in that, The rubber sealing strip is made of natural rubber.

7. The installation device according to claim 2, characterized in that, The upper, lower, left, and right steel plates are coated with a release agent on their concrete-facing surfaces.

8. The installation device according to claim 1, characterized in that, The extrusion sleeve is made of cold-rolled precision seamless steel pipe.

9. A construction method for installing reinforcing bars in the groove of a concrete box girder, employing the installation device as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Based on the position of the crossbeam reinforcement at the box girder slot, a corresponding reserved reinforcement hole is machined on the box wall of the protective box, and the embedded reinforcement is passed through the reserved reinforcement hole; when the device used includes a rubber sealing strip, a rubber sealing strip is also installed in the reserved reinforcement hole to wrap the embedded reinforcement. S2, the several plates are detachably assembled into a protective box, which is then installed at the slot of the box girder, so that the protective box encloses the slot and the embedded steel bars are located inside the protective box; S3, pour the box girder concrete; after the concrete reaches its strength, disassemble the plate and remove the protective box; S4, pass the crossbeam reinforcing bar through the groove and connect it with the pre-embedded reinforcing bar, and use the extrusion sleeve to extrude and connect the two to restore the groove reinforcing bar.

10. The construction method according to claim 9, characterized in that, Before step S1, the cutting length, quantity, and position of the crossbeam reinforcement at the box girder slot are determined by three-dimensional modeling, and the position of the reserved reinforcement hole is determined accordingly; and / or, the protective box removed in step S3 is cleaned and reused for the construction of the next box girder slot.

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