A formwork system for prefabricating a prestressed double-T beam with a fold line

Abstract

The present application relates to a kind of formwork systems for prefabricated fold line pre-tensioning method prestressed double T beam, including formwork foundation, it is characterized in that in formwork foundation, integral outer form is set, two recesses corresponding with the web of double T beam are equipped in the middle of integral outer form, end mould is equipped at the both ends of integral outer form, flange baffle is fixed on integral outer form by magnetic positioner, beam body outer steel strand diverter is installed outside end mould, fold line steel strand bending position is set on formwork foundation below the two recesses, and bending press anchor device is set in corresponding position in recess.Compared with the traditional formwork system for bridge component prefabrication, the present application adopts integral formwork structure and reasonable fold line steel strand bending system, effectively reduces formwork construction and prestress construction operation time, improves work efficiency, reduces energy consumption, greatly improves the industrialization degree of double T beam prefabrication, has good economic benefit, scientific and technological benefit and social benefit, and is worth popularization and application.

Description

Technical Field

[0001] The invention relates to the field of prefabrication of reinforced concrete components for municipal and highway bridges, in particular to a template system for prefabricating prestressed double T beams using a broken line pre-tensioning method. Background Art

[0002] The broken line prestressed concrete beam (box beam, T-beam, etc.) is a new type of prestressed concrete beam that has been used in bridge engineering in my country in recent years. It overcomes the disadvantage that traditional prestressed concrete components using straight prestressed tendons cannot be used for larger spans. It has the advantage of post-tensioned components that the prestressed tendon line shape can be changed, and can be used to build concrete bridges with larger spans.

[0003] At present, the double T-beam with broken-line prestressing has not been applied in the domestic municipal and highway bridge construction fields, and the prefabrication production equipment supporting it has not been developed. Summary of the Invention

[0004] The purpose of the present invention is to provide a template system for prefabricating prestressed double T-beams using a broken line pre-tensioning method, thereby improving the industrialization level of bridge component prefabrication.

[0005] In order to achieve the above-mentioned purpose, the technical solution of the present invention is: a formwork system for prefabricated fold line pre-tensioned prestressed double T beams, including a formwork foundation, characterized in that an integral outer formwork is arranged on the formwork foundation, two grooves corresponding to the webs of the double T beams are provided in the middle of the integral outer formwork, end forms are provided at both ends of the integral outer formwork, the flange baffles are fixed to the integral outer formwork by magnetic locators, a beam body outer steel strand diverter is installed on the outside of the end formwork, a fold line steel strand bending position is set on the formwork foundation below the two grooves, and a bending pressure anchor is set at the corresponding position in the groove.

[0006] Furthermore, the formwork foundation includes a prestressed production pedestal and steel ground beams arranged on the prestressed production pedestal at a certain interval.

[0007] Furthermore, the integral outer formwork includes a double T-beam bending panel, two grooves corresponding to the web of the double T-beam are provided in the middle of the double T-beam bending panel, the top surface of the double T-beam bending panel forms a top plate template corresponding to the top plate of the double T-beam, and the grooves of the double T-beam bending panel form a web template. A number of longitudinal steel sections are welded on the outer side of the double T-beam bending panel along the length direction of the double T-beam bending panel, and longitudinal steel sections are welded at the bottom of each groove of the double T-beam bending panel. Transverse shaping plates are welded on the outer side of the double T-beam bending panel at certain intervals along the length direction of the double T-beam bending panel, and the integral outer formwork is welded to the steel ground beam through the transverse shaping plates or longitudinal steel sections.

[0008] Furthermore, a flexible adjustment strut is provided between the integral outer formwork and the steel ground beam, one end of the flexible adjustment strut is connected to a pin seat welded on the integral outer formwork at a position corresponding to the outer side of the double T-beam top plate, and the other end of the flexible adjustment strut is connected to a pin shaft welded at a position corresponding to the steel ground beam. By adjusting the length of the flexible adjustment strut, the double T-beam bending panel can be deformed, thereby adjusting the opening degree of the groove of the double T-beam bending panel.

[0009] Furthermore, the flexible adjustment support rod includes an internally threaded sleeve and two screw rods located at both ends of the internally threaded sleeve, and the rotation directions of the two screw rods are opposite.

[0010] Furthermore, reserved steel bar positioning holes are provided on the panel of the flange baffle.

[0011] Furthermore, the steel strand diverter outside the beam body includes a base frame, which is provided with a steering shaft and a shaft sleeve mounted on the steering shaft. The base frame is installed on the longitudinal steel section at the bottom of the groove of the double T-beam bending panel through a movable bolt connection mechanism.

[0012] Furthermore, the integral outer formwork is supported by segmented forming and integral welding; the end formwork adopts an embedded structure, and the installation position can be adjusted according to the change of the beam length; the flange baffle is fixed to the integral outer formwork by a magnetic locator, and the length change requirement of the double T-beam cantilever can be met by adjusting the position of the magnetic locator; the steel strand bending system in the beam body is arranged at the bending position of the folded line steel strand, including a bending device and a bending pressure anchor controlled by the bending device, and the bending device is connected to the steel ground beam in the formwork foundation, which is used to control the movement of the bending pressure anchor, thereby controlling the linear shape of the folded line steel strand in the beam body, and can rotate with the change of the steel strand position and the bending angle during the tensioning process; the steel strand diverter outside the beam body is installed on the outside of the end formwork, and is connected and fastened to the outer formwork by a movable bolt connection mechanism installed under the bottom plate of the integral outer formwork, which can adapt to the oblique changes of the beam shape, and the diverter can convert the oblique upward extension direction of the folded line steel strand outside the beam body into a horizontal extension direction, which is convenient for the installation of the tensioning system and meets the long-line production conditions.

[0013] The present invention has obvious technical features through the above-mentioned scheme features. First, the integral steel formwork adopts an integral structure and a combination of rigidity and flexibility, which reduces the process step of disassembling and assembling the side formwork in the traditional bridge prefabrication process, can speed up the construction process, reduce labor intensity, improve work efficiency, and meet the needs of industrialized production of building products; second, the formwork is organically combined with the steel strand bending system inside the beam body, and according to the actual working conditions, one of the bending system working modes such as pulling down from the bottom of the formwork or pressing down from the top of the formwork can be selected to achieve steel strand bending; third, the steel strand diverter outside the beam body is hingedly connected to the end formwork, with a simple structure and easy disassembly, and can be applied to skew beam types and beam length changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a side view of the present invention.

[0015] Figure 2 for Figure 1 End view.

[0016] Figure 3 This is the structural diagram of the integral outer mold.

[0017] Figure 4 This is the structural diagram of the flange baffle.

[0018] Figure 5 This is the end mold structure diagram.

[0019] Figure 6 This is the structural diagram of the steel strand diverter outside the beam body. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and examples.

[0021] like Figure 1 As shown, a formwork system for prefabricating folded-line prestressed double T-beams includes a prestressed production pedestal 1. If the steel strand bending system 8 in the beam body adopts a working mode of pulling down from the bottom of the formwork, the prestressed production pedestal 1 needs to reserve sufficient space below the folded-line steel strand bending point as the operating space for the prestressed steel strand bending system 8 in the beam body; steel ground beams 2 are arranged at a certain interval on the prestressed production pedestal 1, and the steel ground beams 2 are welded to the embedded steel plates in the floor of the prestressed production pedestal 1.

[0022] like Figure 3 As shown, the integral outer formwork 3 is welded by a double T-beam bent panel 31, a longitudinal steel section 32, and a transverse shaping plate 33. The double T-beam bent panel 31 meets the requirements of the beam body's external dimensions, and the longitudinal steel section 32 and the transverse shaping plate 33 ensure the overall rigidity of the formwork; wherein the double T-beam bent panel 31 includes a top surface corresponding to the double T-beam top plate, i.e., the top plate steel formwork, and a groove corresponding to the double T-beam web, i.e., the web steel formwork; the integral outer formwork 3 is welded to the steel ground beam 2 to form a stable structure; the double T-beam bent panel 31 has a certain flexibility at the junction of the double T-beam top plate and the web, which can be adjusted by the flexibility Adjust the support rod 4. The two ends of the flexible adjustment support rod 4 are left and right screw rods 41, which are respectively connected to the pin seats welded on the integral outer formwork 3 and the steel ground beam 2. Rotating the internal threaded sleeve 42 in the flexible adjustment support rod 4 can make the double T-beam bending panel groove, that is, the outer steel formwork of the web open and close and rotate a certain angle; before prestressing, tighten the flexible adjustment support rod 4 to make the outer steel formwork of the web of the integral outer formwork 3 rotate outward. At this time, the component is disengaged from the outer steel formwork of the web of the integral outer formwork 3, which can reduce the friction resistance between the concrete component and the formwork, and facilitate prestressing and component lifting.

[0023] like Figure 4 As shown, the flange baffle 5 is composed of a panel 51, upper and lower flanges 52 and a rib plate 53. The panel 51 is provided with a reserved steel bar positioning hole 54; the flange baffle is fixed to the integral outer mold through a magnetic locator, and the length change requirement of the double T-beam cantilever can be met by adjusting the position of the magnetic locator.

[0024] like Figure 5 As shown, the end mold 6 is composed of a panel 61, a box body 62, a rib plate 63, etc., and a steel strand positioning hole 64 is provided on the panel 61; the end mold 6 is divided into five pieces, of which three are horizontally divided at the top plate position and can be removed before prestressing is released, and one piece is located at each of the webs on both sides, which needs to be removed after prestressing is released. Each piece is connected by bolts to facilitate the disassembly and assembly of the mold; the end mold 6 adopts an embedded structure, and after being installed in place, it is connected to the steel strand diverter 7 outside the beam body through a hinge connection and bolts to form a whole.

[0025] like Figure 6 As shown, the external steel strand diverter 7 of the beam body is composed of a base frame 71, a steering shaft 72, a sleeve 73, a movable bolt connection mechanism 74, etc.; according to the number and arrangement of the double T-beam broken line steel strands, each set of diverters is equipped with a number of steering shafts 72, and each steering shaft 72 is equipped with a number of steering sleeves 73. The steering sleeves 73 are made of MGB material and can be flexibly rotated on the steering shaft 72, which can reduce the friction resistance during the tensioning movement of the steel strands and facilitate the tensioning of a single steel strand and the overall tensioning; the external steel strand diverter 7 of the beam body is installed on the outside of the end mold 6, and 4 nuts 741 are welded on the bottom steel plate of the base frame 71, and corresponding bolt holes 742 are reserved on the steel plate; the movable bolt connection mechanism 74 is used to Fix the steel strand diverter 7 outside the beam body on the integral outer formwork 3. After the steel strand diverter 7 outside the beam body is positioned, lean the movable bolt connection mechanism 74 against the longitudinal steel section 32 at the bottom of the integral outer formwork 3, and pass the bolts 744 from bottom to top through the channels on the movable bolt connection mechanism 74, the reserved holes 743 on the bottom panel of the integral outer formwork 3, and the bolt holes 742 on the bottom steel plate of the base frame 71, and finally screw in the nuts 741 to complete the connection and fixation of the steel strand diverter 7 outside the beam body and the integral outer formwork 3; the reserved holes 743 on the bottom panel of the integral outer formwork 3 are slot-type holes, and the movable bolt connection mechanism 74 can adjust the installation position within a certain range in the longitudinal direction of the template through the reserved holes 743 to adapt to changes in the beam length.

[0026] The prestressed steel strand bending system 8 in the beam body can work in two ways: pulling down from the bottom of the formwork or pressing down from the top of the formwork. The prestressed steel strand bending system 8 in the beam body is installed at the bending point of the broken line steel strands and consists of a bending pressure anchor embedded in the concrete and a bending device connected to the steel ground beam 2. In this embodiment, the bending pressure anchor is located inside the web steel formwork, while the bending device is located outside the web steel membrane. In this way, the bending and positioning of the prestressed steel bars in the web can be completed by operating outside the web steel membrane, thereby solving the problem of achieving prestressed steel bar bending in narrow working conditions. If the working method of pressing down from the top of the formwork is adopted, a crossbeam at the top of the formwork must be added to fix the hydraulic jack that applies downward pressure. Before prestressing is released, the reusable part on the outside of the beam body must be disconnected to ensure normal sliding of the component during release.

[0027] In summary, the formwork system proposed in the present invention for prefabricating prestressed double T-beams using the folded line pre-tensioning method adopts an integral formwork structure and a reasonable folded line steel strand bending system, which effectively reduces the time of formwork construction and prestressing construction operations, improves work efficiency, reduces energy consumption, and greatly improves the degree of industrialization of double T-beam prefabrication, with good economic, scientific and technological and social benefits.

[0028] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be regarded as limiting the present invention, and the protection scope of the present invention should be defined by the appended claims.

Claims

1. A formwork system for prefabricating prestressed double T-beams using a prestressed folding line method, comprising a formwork foundation, characterized in that An integral outer formwork is arranged on the basis of the formwork, and two grooves corresponding to the webs of the double T-beam are arranged in the middle of the integral outer formwork, and end forms are arranged at both ends of the integral outer formwork, and the flange baffles are fixed to the integral outer formwork by magnetic locators, and a steel strand diverter outside the beam body is installed on the outside of the end formwork, and a broken line steel strand bending device is arranged on the basis of the formwork below the two grooves, and a bending pressure anchor is arranged at the corresponding position in the groove; the integral outer formwork is supported by segmented forming and integral welding; the end formwork is divided into five pieces, of which three are horizontally divided at the top plate position and are removed before prestressing, and one piece is arranged at each of the webs on both sides, which need to be removed after prestressing, and each piece is connected by bolts to facilitate disassembly and assembly of the mold; the end formwork adopts an embedded structure, and the installation position can be adjusted according to the change of the beam length. After installation, it is connected to the steel strand diverter outside the beam body by hinges and bolts to form a whole; the flange baffle is fixed by magnetic locators The magnetic locator is fixed on the integral outer formwork, and the length change requirement of the double T-beam cantilever can be met by adjusting the position of the magnetic locator; the steel strand bending system inside the beam body is arranged at the bending position of the folded line steel strand, including a folded line steel strand bending device and a bending pressure anchor controlled by the folded line steel strand bending device, and the folded line steel strand bending device is connected to the steel ground beam in the formwork foundation, and is used to control the movement of the bending pressure anchor, thereby controlling the linear shape of the folded line steel strand in the beam body, and can rotate with the change of the position and bending angle of the folded line steel strand in the tensioning process; the steel strand diverter outside the beam body is installed on the outside of the end formwork, and is connected and fastened to the integral outer formwork through a movable bolt connection mechanism installed under the bottom plate of the integral outer formwork, which can adapt to the oblique changes of the beam shape, and the steel strand diverter outside the beam body can convert the oblique upward extension direction of the folded line steel strand outside the beam body into a horizontal extension direction, which is convenient for the installation of the tensioning system and meets the long-line production conditions.

2. The template system according to claim 1, characterized in that: The template foundation includes a pre-tensioned prestressed production pedestal and steel ground beams arranged on the pre-tensioned prestressed production pedestal at a certain interval.

3. The template system according to claim 1, wherein: The integral outer formwork includes a double T-beam bending panel, two grooves corresponding to the webs of the double T-beams are provided in the middle of the double T-beam bending panel, the top surface of the double T-beam bending panel forms a top plate template corresponding to the top plate of the double T-beam, and the grooves of the double T-beam bending panel form a web template. A number of longitudinal steel sections are welded on the outer side of the double T-beam bending panel along the length direction of the double T-beam bending panel, and longitudinal steel sections are welded at the bottom of each groove of the double T-beam bending panel. Transverse shaping plates are welded on the outer side of the double T-beam bending panel at regular intervals along the length direction of the double T-beam bending panel, and the integral outer formwork is welded to the steel ground beam through the transverse shaping plates or the longitudinal steel sections.

4. The template system according to claim 1, wherein: A flexible adjustment strut is provided between the integral outer formwork and the steel ground beam. One end of the flexible adjustment strut is connected to a pin seat welded on the integral outer formwork at a position corresponding to the outer side of the top plate of the double T-beam, and the other end of the flexible adjustment strut is connected to a pin shaft welded at a corresponding position of the steel ground beam. By adjusting the length of the flexible adjustment strut, the double T-beam bent panel can be deformed, thereby adjusting the opening degree of the groove of the double T-beam bent panel.

5. The template system according to claim 4, characterized in that: The flexible adjustment support rod includes an internal thread sleeve and two screw rods located at both ends of the internal thread sleeve, and the rotation directions of the two screw rods are opposite.

6. The template system according to claim 1, wherein: Reserved steel bar positioning holes are provided on the panel of the flange baffle.

7. The template system according to claim 1, wherein: The external steel strand diverter of the beam body includes a base frame, a steering shaft and a shaft sleeve sleeved on the steering shaft, and the base frame is installed on the longitudinal steel at the bottom of the groove of the double T beam bending panel through a movable bolt connection mechanism.

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