A method for manufacturing precast box girder tracks for highways

Abstract

This invention provides a method for fabricating precast box girder tracks for highways, belonging to the field of track fabrication technology. The method includes the following steps: S1: Concrete preparation, where screened cement, crushed stone, and sand are mixed according to a concrete mix design to obtain castable concrete; S2: Steel frame preparation, where steel bars and prestressed steel strands are combined after ensuring the materials are qualified to obtain a precast steel frame; S3: Concrete pouring, where the concrete pouring equipment includes a steel frame conveying mechanism for positioning and conveying the steel frame, a pouring mold for placing the steel frame for positioning and pouring, a demolding mechanism for quickly demolding the formed precast beam, and a moving pouring mechanism for uniform pouring; S4: Demolding and curing, where the precast beam is cured using curing equipment, ensuring that after the concrete pouring is completed and the slurry has settled, it is covered and watered for curing as soon as possible; S5: Finishing work. This invention facilitates rapid demolding of precast beams, achieving efficient demolding.

Description

Technical Field

[0001] This invention relates to the field of track beam fabrication technology, and more specifically, to a method for fabricating track beams for precast box girders for highways. Background Technology

[0002] Bridge structures, as a special type of product in my country's construction industry, have played a significant role in the development of the national economy. However, the traditional extensive, fragmented, energy-intensive, and inefficient bridge construction model has resulted in serious problems such as long construction cycles, high costs, uncontrollable quality, and resource waste. Industrialization of construction is the main way to solve the problem of fragmented construction. Precast beam structures, due to their characteristics of numerous points, wide areas, long lines, and complex engineering site environments, face many problems in design, construction, and operation and maintenance due to traditional construction methods. These problems include long design and construction cycles, frequent engineering quality problems, waste of engineering materials leading to increased costs, and damage to the original surrounding environment. The problems of long construction periods, serious resource waste, and low engineering quality in traditional construction methods are particularly evident in the construction of large bridges such as large bridges and super-large bridges. Prefabricated bridges, with their superior characteristics, have solved these problems. As a unique large-scale temporary project in prefabricated bridge engineering, the beam yard is characterized by large construction investment, short operation cycle, and high beam fabrication requirements. It plays a huge role in the bridge prefabrication process. It can be seen that the prefabrication beam yard is a key guarantee for the development of prefabricated bridges. In the entire prefabricated bridge project, the prefabrication beam yard plays a huge role in ensuring construction quality, progress, construction cost, and information management.

[0003] Existing precast beam preparation methods can only construct bridges in a traditional way. Precast beam yards suffer from chaotic and disorderly construction and management due to the complexity of on-site operations, resulting in serious waste of resources. The improper disposal of construction waste also has a serious impact on the environment. Moreover, most of the equipment used is traditional equipment, which is not only inconvenient for casting and demolding precast beams, but also cannot ensure that the overall concrete is fully poured into the steel frame, thus reducing the forming effect of precast beams. Summary of the Invention

[0004] The purpose of this invention is to provide a method for manufacturing precast box girder tracks for highways, which facilitates rapid demolding of precast beams and achieves efficient demolding.

[0005] The embodiments of the present invention are achieved through the following technical solution: a method for manufacturing precast box girder tracks for highways, the method being as follows:

[0006] S1: Concrete preparation, preparing concrete for the foundation material of precast box girder track beam, screening high-quality cement, crushed stone and sand, and removing unqualified and poor-quality cement, crushed stone and sand, and mixing the screened cement, crushed stone and sand according to the concrete mix proportion, that is, adding water and admixtures to mix, to obtain the cast concrete.

[0007] S2: Steel frame preparation. The steel frame of the precast box girder track beam foundation material is prepared. The steel bars and prestressed steel strands required for steel frame preparation are monitored to ensure that there are no defects such as cracks, burrs, mechanical damage, oil stains, or dead bends on the surface of the steel bars and prestressed steel strands. Tensile tests are conducted on the steel bars and prestressed steel strands to ensure that the materials are qualified. After that, the steel bars and prestressed steel strands are combined to obtain the precast steel frame.

[0008] S3: Concrete pouring. The precast box girder track beam foundation steel frame is transported to the mold in the concrete pouring point for positioning. After the precast box girder track beam foundation steel frame is positioned, the concrete is poured. The mixed concrete is poured into the mold. The concrete pouring equipment includes a steel frame conveying mechanism for positioning and conveying the steel frame, a pouring mold for placing the steel frame for positioning and pouring, a demolding mechanism for quickly demolding the formed precast beam, and a moving pouring mechanism for uniform pouring.

[0009] S4: Demolding and curing. When the concrete strength reaches 2.5 MPa, the precast beam is demolded and cured using curing equipment. After the concrete is poured, it is covered and watered as soon as possible after the slurry is finished, and the concrete surface is kept moist for no less than 7 days.

[0010] S5: Final work. Prestressed tendons can only be tensioned when the concrete of the box girder reaches 90% of the design strength. Tensioning should be carried out symmetrically, slowly and uniformly. Tensioning should be done from both ends, and the two ends should be closely connected and kept synchronized. Grouting should be carried out as soon as possible after tensioning to complete the preparation of the precast beam.

[0011] Furthermore, the steel frame conveying mechanism includes an installation guide rail, with a conveying platform movably connected to the upper end of the installation guide rail, and an installation guide wheel rotatably connected to the lower end of the conveying platform. The installation guide wheel is movably connected to the installation guide rail, and a limit plate is fixedly connected to the upper end of the conveying platform. A positioning cylinder is fixedly connected to the outer side of the limit plate, and the movable end of the positioning cylinder extends through the outer side of the limit plate to the inner side of the limit plate.

[0012] Furthermore, the casting mold includes a bottom mold, and a positioning platform is provided at the lower end of the bottom mold. The four walls of the positioning platform are fixedly connected with height adjusting cylinders for vertical adjustment. The movable end of the height adjusting cylinder is fixedly connected with a horizontal adjusting cylinder for horizontal adjustment. The movable end of the horizontal adjusting cylinder in the length direction of the bottom mold is fixedly connected with a first side template, and the movable end of the horizontal adjusting cylinder in the width direction of the bottom mold is fixedly connected with a second side template. The shapes and sizes of the first side template, the second side template, and the adjacent sides of the bottom mold are compatible.

[0013] Furthermore, a first sealing block is fixedly connected to the side of the first side template and the second side template near the bottom mold. A first sealing groove adapted to the first sealing block is opened on the side wall of the bottom mold. A second sealing block is fixedly connected to the side of the first side template near the second side template. A second sealing groove adapted to the second sealing block is opened on the side wall of the second side template.

[0014] Furthermore, the demolding mechanism includes a mounting base plate fixed to the lower end of the positioning platform. An ejector cylinder is fixedly connected to the upper end of the mounting base plate, and an ejector plate is fixedly connected to the movable end of the ejector cylinder. The ejector plate is movably connected to the bottom mold. A mounting sleeve is fixedly connected to the upper end of the mounting base plate, and a movable rod is fixedly connected to the lower end of the ejector plate. The mounting sleeve has a movable hole inside that matches the movable rod, and the outer diameter of the movable rod is equal to the inner diameter of the movable hole.

[0015] Furthermore, the mobile pouring mechanism includes a fixed frame, one end of which is fixedly connected to a motor. The output end of the motor extends through the outside of the fixed frame into the inside of the fixed frame. The output end of the motor is fixedly connected to a lead screw body. A lead screw nut adapted to the lead screw body is movably connected to the outside of the lead screw body. A mixing tank is fixedly connected to the upper end of the lead screw nut. A suction pump is fixedly connected to the discharge port of the mixing tank. The suction end of the suction pump extends through the discharge port of the mixing tank into the inside of the mixing tank. A fixed horizontal pipe is fixedly connected to the discharge end of the suction pump. A pouring pipe is fixedly connected to the lower end of the fixed horizontal pipe. Three sets of pouring pipes are evenly distributed at the lower end of the fixed horizontal pipe.

[0016] Furthermore, a stirring motor is fixedly connected to the upper end of the mixing tank, and the output end of the stirring motor extends through the upper end of the mixing tank into the interior of the mixing tank. A stirring rod is fixedly connected to the output end of the stirring motor, and stirring blades are fixedly connected to the outside of the stirring rod. The stirring blades are evenly distributed on the outside of the stirring rod.

[0017] Furthermore, a clamping cylinder is fixedly connected to the rear end of the fixed horizontal tube, a clamping plate is fixedly connected to the movable end of the clamping cylinder, a circulation pump is fixedly connected to the side wall of the mixing tank, the suction end of the circulation pump extends through the side wall of the mixing tank into the interior of the mixing tank, and a circulation pipe is fixedly connected to the discharge end of the circulation pump, the upper end of the circulation pipe extends through the side wall of the mixing tank into the interior of the mixing tank.

[0018] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0019] 1. This invention uses a steel frame conveying mechanism with a positioning and engaging structure to convey the steel frame, thereby ensuring that the steel frame will not tip over or shift during the conveying process, thus ensuring the safe transport of the steel frame, reducing damage caused by expansion during transport, increasing overall transport safety, and achieving the effect of safe operation of the steel frame.

[0020] 2. By setting a casting mold with a demolding mechanism, the present invention can quickly separate the mold after the precast beam is formed, which facilitates the quick removal of the formed precast beam. In addition, the bottom mold is equipped with an ejection mechanism after the mold is separated, which facilitates the quick demolding of the whole, ensuring that the whole has a fast processing efficiency and achieving the effect of high-efficiency demolding.

[0021] 3. By setting up a mobile pouring mechanism with a mobile spraying system, the present invention can quickly and evenly spray existing concrete into the mold, ensuring a good overall pouring effect. At the same time, a clamping cylinder is set at the rear end of the spraying pipe, which can initially compact the precast beam to ensure the subsequent shaping effect, thus achieving the effect of mobile pouring. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is a three-dimensional structural diagram of the casting mold of the present invention;

[0025] Figure 3 This is a schematic diagram showing the disassembled structure of the casting mold of the present invention;

[0026] Figure 4 For the present invention Figure 3 Schematic diagram of the disassembled structure of the movable rod at the location;

[0027] Figure 5 This is a three-dimensional structural diagram of the mobile pouring mechanism of the present invention;

[0028] Figure 6 This is a schematic diagram of the internal structure of the mixing tank of the present invention.

[0029] Icons: 1. Steel frame conveyor mechanism; 2. Casting mold; 3. Demolding mechanism; 4. Moving casting mechanism; 11. Mounting guide rail; 12. Conveying platform; 13. Mounting guide wheel; 14. Limiting plate; 15. Positioning cylinder; 21. Bottom mold; 22. Positioning platform; 23. Height adjustment cylinder; 24. Lateral adjustment cylinder; 25. First side template; 26. Second side template; 27. First sealing block; 28. First sealing groove; 29. ​​Second sealing block; 210. Second sealing groove 31. Mounting base plate; 32. Ejector cylinder; 33. Ejector plate; 34. Mounting sleeve; 35. Movable rod; 36. Movable hole; 41. Fixed frame; 42. Motor; 43. Lead screw body; 44. Lead screw nut; 45. Mixing tank; 46. Suction pump; 47. Fixed horizontal pipe; 48. Pouring pipe; 49. Mixing motor; 410. Mixing rod; 411. Mixing blade; 412. Pressing cylinder; 413. Pressing plate; 414. Circulation pump; 415. Circulation pipe. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. Example

[0032] The following description, in conjunction with specific embodiments, provides further details. Figures 1-6 As shown, the present invention provides a method for fabricating precast box girder tracks for highways, the method of which is as follows:

[0033] S1: Concrete preparation, preparing concrete for the foundation material of precast box girder track beam, screening high-quality cement, crushed stone and sand, and removing unqualified and poor-quality cement, crushed stone and sand, and mixing the screened cement, crushed stone and sand according to the concrete mix proportion, that is, adding water and admixtures to mix, to obtain the cast concrete.

[0034] S2: Steel frame preparation. The steel frame of the precast box girder track beam foundation material is prepared. The steel bars and prestressed steel strands required for steel frame preparation are monitored to ensure that there are no defects such as cracks, burrs, mechanical damage, oil stains, or dead bends on the surface of the steel bars and prestressed steel strands. Tensile tests are conducted on the steel bars and prestressed steel strands to ensure that the materials are qualified. After that, the steel bars and prestressed steel strands are combined to obtain the precast steel frame.

[0035] S3: Concrete pouring. The precast box girder track beam foundation steel frame is transported to the mold in the concrete pouring point for positioning. After the precast box girder track beam foundation steel frame is positioned, the concrete is poured. The mixed concrete is poured into the mold. The concrete pouring equipment includes a steel frame conveying mechanism 1 for positioning and conveying the steel frame, a pouring mold 2 for placing the steel frame for positioning and pouring, a demolding mechanism 3 for quickly demolding the formed precast beam, and a moving pouring mechanism 4 for uniform pouring.

[0036] S4: Demolding and curing. When the concrete strength reaches 2.5 MPa, the precast beam is demolded and cured using curing equipment. After the concrete is poured, it is covered and watered as soon as possible after the slurry is finished, and the concrete surface is kept moist for no less than 7 days.

[0037] S5: Final work. Prestressed tendons can only be tensioned when the concrete of the box girder reaches 90% of the design strength. Tensioning should be carried out symmetrically, slowly and uniformly. Tensioning should be done from both ends, and the two ends should be closely connected and kept synchronized. Grouting should be carried out as soon as possible after tensioning to complete the preparation of the precast beam.

[0038] Reference Figure 1The steel frame conveying mechanism 1 includes an installation guide rail 11. A conveying platform 12 is movably connected to the upper end of the installation guide rail 11, and an installation guide wheel 13 is rotatably connected to the lower end of the conveying platform 12. The installation guide wheel 13 is movably connected to the installation guide rail 11. A limit plate 14 is fixedly connected to the upper end of the conveying platform 12. A positioning cylinder 15 is fixedly connected to the outer side of the limit plate 14. The movable end of the positioning cylinder 15 extends through the outer side of the limit plate 14 to the inner side of the limit plate 14. The positioning cylinder 15 and the limit plate 14 are symmetrically distributed about the horizontal center line of the conveying platform 12, and multiple sets of positioning cylinders 15 and limit plates 14 are distributed on the upper end of the conveying platform 12, which facilitates the overall positioning and conveying and increases the overall conveying stability. The installation guide wheel 13 is not just a wheel, but a movable base with a drive mechanism. It is convenient to correspond with the installation guide rail 11 and is not the focus of this design, so it is not described in detail in the abstract.

[0039] Reference Figure 2 and Figure 3 The casting mold 2 includes a bottom mold 21. A positioning platform 22 is located at the lower end of the bottom mold 21. Height-adjusting cylinders 23 for vertical adjustment are fixedly connected to the four walls of the positioning platform 22. A horizontal adjustment cylinder 24 for horizontal adjustment is fixedly connected to the movable end of the height-adjusting cylinders 23. A first side template 25 is fixedly connected to the movable end of the horizontal adjustment cylinder 24 in the length direction of the bottom mold 21, and a second side template 26 is fixedly connected to the movable end of the horizontal adjustment cylinder 24 in the width direction of the bottom mold 21. The shapes and sizes of the adjacent sides of the first side template 25, the second side template 26, and the bottom mold 21 are compatible, allowing for full fit and positioning, thereby ensuring proper casting. The position of the reinforcing bars is defined and can be easily disassembled, thus facilitating the demolding of the precast beam. The first side formwork 25 and the second side formwork 26 are fixedly connected to the side of the bottom formwork 21 with a first sealing block 27. The side wall of the bottom formwork 21 is provided with a first sealing groove 28 that matches the first sealing block 27. The first side formwork 25 is fixedly connected to the side of the second side formwork 26 with a second sealing block 29. The side wall of the second side formwork 26 is provided with a second sealing groove 210 that matches the second sealing block 29. The first sealing block 27 and the first sealing groove 28 can fully fit and seal, and the second sealing block 29 and the second sealing groove 210 can also fully fit and seal, ensuring a good overall sealing effect.

[0040] Reference Figure 4The demolding mechanism 3 includes a mounting base plate 31 fixed to the lower end of the positioning platform 22. An ejector cylinder 32 is fixedly connected to the upper end of the mounting base plate 31. An ejector plate 33 is fixedly connected to the movable end of the ejector cylinder 32. The ejector plate 33 is movably connected to the bottom mold 21. A mounting sleeve 34 is fixedly connected to the upper end of the mounting base plate 31. A movable rod 35 is fixedly connected to the lower end of the ejector plate 33. The mounting sleeve 34 has a movable hole 36 that matches the movable rod 35. The outer diameter of the movable rod 35 is equal to the inner diameter of the movable hole 36. The movable rod 35 will not deviate during the movement of the mounting sleeve 34, thereby ensuring the stability of the overall adjustment and reducing the possibility of deviation during demolding.

[0041] Reference Figure 5 The mobile pouring mechanism 4 includes a fixed frame 41. A motor 42 is fixedly connected to one end of the fixed frame 41. The output end of the motor 42 extends through the outside of the fixed frame 41 and into its interior. A lead screw body 43 is fixedly connected to the output end of the motor 42. A lead screw nut 44, compatible with the lead screw body 43, is movably connected to the outside of the lead screw body 43. A mixing tank 45 is fixedly connected to the upper end of the lead screw nut 44. A suction pump 46 is fixedly connected to the outlet of the mixing tank 45. The suction end of the suction pump 46 extends through the outlet of the mixing tank 45 and into its interior. A fixed horizontal pipe 47 is fixedly connected to the outlet end of the suction pump 46. A pouring pipe 48 is fixedly connected to the lower end of the fixed horizontal pipe 47. The pouring pipe 48 is located within the fixed horizontal pipe 47. Three sets of equal-spaced concrete pipes are distributed at the lower end. The pouring pipe 48 is driven by the relative movement of the screw body 43 and the screw nut 44 to spray the concrete horizontally, ensuring that the concrete is fully poured and improving the overall pouring effect. The rear end of the fixed horizontal pipe 47 is fixedly connected to the clamping cylinder 412, and the movable end of the clamping cylinder 412 is fixedly connected to the clamping plate 413. The side wall of the mixing tank 45 is fixedly connected to the circulating pump 414. The suction end of the circulating pump 414 extends through the side wall of the mixing tank 45 into the interior of the mixing tank 45. The discharge end of the circulating pump 414 is fixedly connected to the circulating pipe 415. The upper end of the circulating pipe 415 extends through the side wall of the mixing tank 45 into the interior of the mixing tank 45, ensuring that the concrete does not solidify during the mixing process and improving the overall pouring effect.

[0042] Reference Figure 6 A mixing motor 49 is fixedly connected to the upper end of the mixing tank 45. The output end of the mixing motor 49 extends through the upper end of the mixing tank 45 into the interior of the mixing tank 45. A mixing rod 410 is fixedly connected to the output end of the mixing motor 49. A mixing blade 411 is fixedly connected to the outside of the mixing rod 410. The mixing blade 411 is evenly distributed on the outside of the mixing rod 410. The mixing motor 49 drives the mixing rod 410 and the mixing blade 411 to rotate, preventing the concrete from solidifying before pouring.

[0043] The working process of this embodiment involves preparing the concrete foundation material for the precast box girder track beam, screening high-quality cement, crushed stone, and sand, and discarding substandard or poor-quality cement, crushed stone, and sand. The screened cement, crushed stone, and sand are then mixed according to the concrete mix design, i.e., water and admixtures are added and stirred to obtain the cast-in-place concrete. The steel frame for the precast box girder track beam foundation material is then prepared. The reinforcing bars and prestressed steel strands required for preparing the steel frame are monitored to ensure that the surfaces of the reinforcing bars and prestressed steel strands are free from defects such as cracks, burrs, mechanical damage, oil stains, and sharp bends. Tensile stress is then applied to the reinforcing bars and prestressed steel strands. After ensuring the materials are qualified, the reinforcing bars and prestressed steel strands are combined to obtain a precast steel frame. The precast steel frame is then placed on the upper end of the conveying platform 12, and the positioning cylinder 15 simultaneously presses and positions the precast steel frame. At the same time, the position of the precast steel frame is moved by the drive installation guide wheels 13 within the installation guide rail 11. When it reaches the casting mold 2, the steel frame is hoisted into the casting mold 2, ensuring that the bottom mold 21, the first side mold 25, and the second side mold 26 are fully fitted. Simultaneously, a suction pump 46 draws concrete from the mixing tank 45 and sprays it into the casting mold 2. During the concrete pouring process, the mixing cylinder... The machine 49 drives the mixing rod 410 and mixing blades 411 to rotate, preventing the concrete from solidifying before pouring. The circulating pump 414 draws concrete from the bottom of the mixing tank 45 and discharges it back into the upper part of the mixing tank 45 through the circulating pipe 415, preventing the concrete from solidifying at the bottom. Simultaneously, during the pouring process, the motor 42 drives the lead screw body 43 to rotate, and the rotation of the lead screw body 43 causes the lead screw nut 44 and the mixing tank 45 to move laterally, achieving mobile pouring and ensuring sufficient concrete pouring. When the concrete strength reaches 2.5 MPa, the precast beam is demolded using the lateral adjustment cylinder 24. The first side formwork 25 and the second side formwork 26 are moved to separate the precast beam. At the same time, the ejector cylinder 32 pushes the ejector plate 33 and the precast beam to separate the precast beam from the bottom formwork 21, achieving rapid demolding. Then, the precast beam is cured using curing equipment. After the concrete is poured, it should be covered and watered as soon as possible after the grout has settled, keeping the concrete surface moist for no less than 7 days. The prestressed tendons can only be tensioned when the box girder concrete reaches 90% of the design strength. Tensioning should be carried out symmetrically, slowly and uniformly. Tensioning should be done from both ends, and the two ends should be closely connected and kept synchronized. After tensioning, grouting should be carried out as soon as possible to complete the preparation of the precast beam.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for fabricating precast box girder track for highways, characterized in that: The method is as follows: S1: Concrete preparation, preparing concrete for the foundation material of precast box girder track beam, screening high-quality cement, crushed stone and sand, and removing unqualified and poor-quality cement, crushed stone and sand, and mixing the screened cement, crushed stone and sand according to the concrete mix proportion, that is, adding water and admixtures to mix, to obtain the cast concrete. S2: Steel frame preparation. The steel frame of the precast box girder track beam foundation material is prepared. The steel bars and prestressed steel strands required for steel frame preparation are monitored to ensure that there are no defects such as cracks, burrs, mechanical damage, oil stains, or dead bends on the surface of the steel bars and prestressed steel strands. Tensile tests are conducted on the steel bars and prestressed steel strands to ensure that the materials are qualified. After that, the steel bars and prestressed steel strands are combined to obtain the precast steel frame. S3: Concrete pouring, the precast box girder track beam foundation steel frame is transported to the mold in the concrete pouring point for positioning, and the precast box girder track beam foundation steel frame is positioned and then poured. The mixed concrete is poured into the mold. The concrete pouring equipment includes a steel frame conveying mechanism (1) for positioning and conveying the steel frame, a pouring mold (2) for placing the steel frame for positioning and pouring, a demolding mechanism (3) for quickly demolding the formed precast beam, and a moving pouring mechanism (4) for uniform pouring. S4: Demolding and curing. When the concrete strength reaches 2.5 MPa, the precast beam is demolded and cured using curing equipment. After the concrete is poured, it is covered and watered as soon as possible after the slurry is finished, and the concrete surface is kept moist for no less than 7 days. S5: Final work. When the concrete of the box girder reaches 90% of the design strength, the prestressed tendons can be tensioned. Tensioning should be carried out symmetrically, slowly and uniformly. Tensioning should be done from both ends, and the two ends should be closely connected and kept in sync. After tensioning is completed, grouting should be carried out as soon as possible to complete the preparation of the precast beam. The steel frame conveying mechanism (1) includes an installation guide rail (11) inside. The upper end of the installation guide rail (11) is movably connected to a conveying platform (12). The lower end of the conveying platform (12) is rotatably connected to an installation guide wheel (13). The installation guide wheel (13) is movably connected to the installation guide rail (11). The upper end of the conveying platform (12) is fixedly connected to a limiting plate (14). The outer side of the limiting plate (14) is fixedly connected to a positioning cylinder (15). The movable end of the positioning cylinder (15) extends through the outer side of the limiting plate (14) to the inner side of the limiting plate (14).

2. The method for fabricating precast box girder tracks for highways according to claim 1, characterized in that: The casting mold (2) includes a bottom mold (21) inside. A positioning platform (22) is provided at the lower end of the bottom mold (21). The four walls of the positioning platform (22) are fixedly connected with height adjustment cylinders (23) for vertical adjustment. The movable end of the height adjustment cylinder (23) is fixedly connected with a horizontal adjustment cylinder (24) for horizontal adjustment. The movable end of the horizontal adjustment cylinder (24) in the length direction of the bottom mold (21) is fixedly connected with a first side template (25). The movable end of the horizontal adjustment cylinder (24) in the width direction of the bottom mold (21) is fixedly connected with a second side template (26). The shapes and sizes of the adjacent sides of the first side template (25), the second side template (26) and the bottom mold (21) are compatible.

3. The method for fabricating precast box girder tracks for highways according to claim 2, characterized in that: The first side template (25) and the second side template (26) are fixedly connected to the side of the bottom mold (21) with a first sealing block (27). The side wall of the bottom mold (21) is provided with a first sealing groove (28) that matches the first sealing block (27). The side of the first side template (25) is fixedly connected to a second sealing block (29). The side wall of the second side template (26) is provided with a second sealing groove (210) that matches the second sealing block (29).

4. The method for fabricating precast box girder tracks for highways according to claim 3, characterized in that: The demolding mechanism (3) includes a mounting base plate (31) fixed to the lower end of the positioning platform (22). An ejector cylinder (32) is fixedly connected to the upper end of the mounting base plate (31). An ejector plate (33) is fixedly connected to the movable end of the ejector cylinder (32). The ejector plate (33) is movably connected to the bottom mold (21). An mounting sleeve (34) is fixedly connected to the upper end of the mounting base plate (31). A movable rod (35) is fixedly connected to the lower end of the ejector plate (33). An movable hole (36) adapted to the movable rod (35) is opened inside the mounting sleeve (34). The outer diameter of the movable rod (35) is equal to the inner diameter of the movable hole (36).

5. The method for fabricating precast box girder tracks for highways according to claim 4, characterized in that: The mobile pouring mechanism (4) includes a fixed frame (41) inside. One end of the fixed frame (41) is fixedly connected to a motor (42). The output end of the motor (42) extends through the outside of the fixed frame (41) into the inside of the fixed frame (41). The output end of the motor (42) is fixedly connected to a lead screw body (43). A lead screw nut (44) adapted to the lead screw body (43) is movably connected to the outside of the lead screw body (43). 44) A mixing tank (45) is fixedly connected to the upper end. A suction pump (46) is fixedly connected to the discharge port of the mixing tank (45). The suction end of the suction pump (46) extends through the discharge port of the mixing tank (45) into the interior of the mixing tank (45). A fixed horizontal pipe (47) is fixedly connected to the discharge end of the suction pump (46). A casting pipe (48) is fixedly connected to the lower end of the fixed horizontal pipe (47). Three sets of casting pipes (48) are evenly distributed at the lower end of the fixed horizontal pipe (47).

6. The method for fabricating precast box girder tracks for highways according to claim 5, characterized in that: A stirring motor (49) is fixedly connected to the upper end of the stirring tank (45). The output end of the stirring motor (49) extends through the upper end of the stirring tank (45) into the interior of the stirring tank (45). A stirring rod (410) is fixedly connected to the output end of the stirring motor (49). A stirring blade (411) is fixedly connected to the outside of the stirring rod (410). The stirring blade (411) is evenly distributed on the outside of the stirring rod (410).

7. The method for fabricating precast box girder tracks for highways according to claim 6, characterized in that: A clamping cylinder (412) is fixedly connected to the rear end of the fixed horizontal tube (47). A clamping plate (413) is fixedly connected to the movable end of the clamping cylinder (412). A circulating pump (414) is fixedly connected to the side wall of the mixing tank (45). The suction end of the circulating pump (414) extends through the side wall of the mixing tank (45) into the interior of the mixing tank (45). A circulating pipe (415) is fixedly connected to the discharge end of the circulating pump (414). The upper end of the circulating pipe (415) extends through the side wall of the mixing tank (45) into the interior of the mixing tank (45).

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