Formwork-free prefabricated box girder

Abstract

The utility model relates to the field of box girders, and provides a formwork-free prefabricated box girder, a flange plate of the box girder is provided with a semi-U-shaped groove, and the grooves of two adjacent box girders are spliced into a complete U-shaped groove. The prefabricated box girder has the beneficial effects that the box girder is prefabricated in a factory in advance, and the semi-U-shaped grooves are formed in the flange plates, so that a mold for pouring concrete can be formed only by splicing the grooves of adjacent box girders during site construction, and an additional mold does not need to be erected. By means of the design, the construction process is greatly simplified, the construction period is shortened, the method is particularly suitable for projects with short construction periods or complex construction conditions, and the overall construction efficiency is remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of box girder technology, specifically to a precast box girder that does not require formwork support. Background Technology

[0002] Box girders are widely used in bridges with small to medium spans due to their advantages such as convenient erection, rapid construction, and reliable quality. This structural form not only meets the safety and durability requirements of modern bridge engineering but also effectively reduces construction difficulty and project costs. In the construction of new highways, precast small box girders are generally used, mainly because they offer significant advantages such as high standardization, short construction period, and strict quality control.

[0003] In the process of erecting box girder bridge decks, transverse connections are a crucial link, and their construction quality directly affects the overall stability and service life of the bridge. Cast-in-place wet joint connections are the most common and reliable method for transverse connections, especially in complex construction environments crossing existing railways, highways, or urban roads, where their importance is even more pronounced. Traditional wet joints generally use the suspended formwork method, requiring formwork installation. To ensure construction safety and smooth traffic flow, construction teams often need to take a series of rigorous measures, such as blocking traffic or erecting sheds, to prevent potential falling objects from affecting traffic during construction.

[0004] For bridge projects that cross important transportation routes, the construction team also needs to work closely with the traffic management department to develop a scientific and reasonable traffic diversion plan, and monitor the construction process in real time and adjust the construction plan in a timely manner to minimize the impact on traffic. Therefore, there is an urgent need to propose a precast box girder that can eliminate the need for formwork. Utility Model Content

[0005] To address the shortcomings of existing technologies, this paper aims to solve the problem of traffic disruption caused by the need for formwork during the construction of precast box girders.

[0006] This utility model provides a precast box girder that does not require formwork support. The flange plate of the box girder is provided with a semi-U-shaped groove, and the grooves of two adjacent box girders are joined together to form a complete U-shaped groove.

[0007] As a preferred embodiment, the U-shaped groove uses lapped reinforcing bars in the longitudinal direction of the bridge.

[0008] As a preferred embodiment, UHPC is injected into the U-shaped groove to form a UHPC wet joint.

[0009] As a preferred embodiment, the width of the U-shaped groove is not less than 150 mm, and the depth is not less than four-fifths of the flange height.

[0010] As a preferred embodiment, the joint of the U-shaped groove is provided with epoxy resin or a sealing strip.

[0011] The beneficial effects of this utility model are as follows:

[0012] 1. This utility model prefabricates the box girders in the factory and sets semi-U-shaped grooves on the flange plates, so that during on-site construction, the grooves of adjacent box girders are simply spliced ​​together to form a mold for pouring concrete, without the need for additional formwork. This design greatly simplifies the construction process, shortens the construction cycle, and is especially suitable for projects with tight schedules or complex construction conditions, significantly improving overall construction efficiency.

[0013] 2. This utility model enhances the overall structural integrity by injecting UHPC into the U-shaped groove to form a wet joint. This allows the wet joint to fully fill and wrap the lapped reinforcing bars, creating a uniform stress system and effectively improving the connection strength and stability between box girders. This structural design not only better distributes loads but also enhances the overall bending and shear resistance of the bridge, ensuring its safety and durability during long-term use. Attached Figure Description

[0014] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] Figure 2 This is an enlarged schematic diagram of part A of this utility model.

[0017] The numbers in the attached diagram are:

[0018] 1-Flange plate; 2-U-shaped groove; 3-Box girder; 4-UHPC wet joint; 5-Lap reinforcement. Detailed Implementation

[0019] To illustrate the features of this utility model, the following description, in conjunction with the accompanying drawings and embodiments, will further explain this utility model.

[0020] Example:

[0021] refer to Figure 1 and Figure 2This embodiment provides a precast box girder that requires no formwork. The flange plate 1 of the box girder 3 has a semi-U-shaped groove, and the grooves of two adjacent box girders 3 are joined to form a complete U-shaped groove 2. By prefabricating the box girders in a factory and setting the semi-U-shaped grooves on the flange plates, on-site construction only requires joining the grooves of adjacent box girders to form a mold for pouring concrete, eliminating the need for additional formwork. This design greatly simplifies the construction process, shortens the construction cycle, and is particularly suitable for projects with tight schedules or complex construction conditions, significantly improving overall construction efficiency.

[0022] Preferably, in this embodiment, the U-shaped groove 2 uses lapped steel bars 5 in the longitudinal direction of the bridge.

[0023] Preferably, in this embodiment, UHPC is injected into the U-shaped groove 2 to form a UHPC wet connector 4.

[0024] By injecting UHPC into the U-shaped groove to form a wet joint, the overall integrity of the structure is further enhanced. This allows the wet joint to fully fill and wrap the lapped reinforcing bars, forming a uniform stress system and effectively improving the connection strength and stability between box girders. This structural design not only better distributes the load but also enhances the overall bending and shear resistance of the bridge, ensuring its safety and durability in long-term use.

[0025] Preferably, in this embodiment, the width of the U-shaped groove 2 is set to 180mm, and the depth is 4 / 5 of the height of the flange plate 1.

[0026] Preferably, in this embodiment, the joint of the U-shaped groove 2 is sealed with epoxy resin to ensure that no leakage occurs.

[0027] This embodiment prefabricates the box girders in the factory and sets semi-U-shaped grooves on the flange plates, so that during on-site construction, the grooves of adjacent box girders are simply spliced ​​together to form a mold for pouring concrete, eliminating the need for additional formwork. This design greatly simplifies the construction process, shortens the construction cycle, and is especially suitable for projects with tight schedules or complex construction conditions, significantly improving overall construction efficiency.

[0028] The above embodiments and accompanying drawings are only used to illustrate the technical solutions of this utility model and are not intended to limit this utility model. This utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of this utility model do not depart from the spirit of this utility model and should also fall within the protection scope of the claims of this utility model. Other related technical structures not disclosed in detail in this utility model are existing technologies in the art.

Claims

1. A precast box girder without formwork support, characterized in that: The flange plate (1) of the box girder (3) is provided with a semi-U-shaped groove, and the grooves of two adjacent box girders (3) are joined together to form a complete U-shaped groove (2).

2. The precast box girder without formwork as described in claim 1, characterized in that: The U-shaped groove (2) uses lapped steel bars (5) in the longitudinal direction.

3. The precast box girder without formwork as described in claim 1, characterized in that: UHPC is injected into the U-shaped groove (2) to form a UHPC wet joint (4).

4. The precast box girder without formwork as described in claim 1, characterized in that: The width of the U-shaped groove (2) is not less than 150 mm, and the depth is not less than 4 / 5 of the height of the flange plate (1).

5. The precast box girder without formwork as described in claim 1, characterized in that: The joint of the U-shaped groove (2) is made of epoxy resin or a sealing strip.

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