A formwork structure for a steel bridge pier column protective layer

Abstract

The utility model discloses a formwork concreting structure for steel bridge pier column protective layer, including formwork, formwork adopts wooden formwork, and the wooden formwork forms the frame on the four sides of pier column base surface, and the back of formwork is fixedly connected with a plurality of secondary beams in vertical direction, and the secondary beam adopts 3*6cm square wood, and the interval is 25cm, and a plurality of secondary beams are fixedly connected with support fixing frame outside, and the support fixing frame includes 2 I -steel arranged on each side of pier column base surface, tie rod and steel pipe, and the 2 I -steel are main beams, and the 2 I -steel are arranged respectively up and down and are abutted on the secondary beam, and the two groups of I -steel of opposite sides adopt four tie rods and single tie rod single end and adopt two steel pipes arranged in vertical direction to lock, and the two ends of the two groups of I -steel of the other two sides are put on the two groups of I -steel fixedly and are abutted and fixed by depending on the inside steel pipe. The utility model discloses the formwork structure stability is good, guarantees the concreting surface quality, and the integral structure is single section one -off forming, guarantees the concreting quality, and the convenient and fast dismounting and assembling, and the formwork can also be repeatedly used.

Description

Technical Field

[0001] This utility model belongs to the field of steel bridge pier construction technology, and relates to a formwork casting structure for the protective layer of steel bridge piers. Background Technology

[0002] A high-speed railway bridge uses 10 steel box girder arch ribs to form its substructure. Each arch rib has a rectangular cross-section, 3300mm wide and 1200mm high, with a center-to-center spacing of 4060mm. The standard section has a 10mm thick top, bottom, and web plate, with thickened dimensions at the arch feet of the side and middle piers. C50 shrinkage-compensating concrete is poured into the arch feet of the side piers and the interior of the middle pier columns. The outer surface of the pier columns in the water-crossing sections requires a 3cm UHPC concrete cladding for corrosion protection. When erecting the formwork, conventional wooden formwork requires a large amount of square timber for reinforcement and nailing on the back, compromising stability. Furthermore, dismantling is time-consuming and labor-intensive. Additionally, this application uses segmented pouring along the height, requiring the reuse of the formwork. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a formwork casting structure for the protective layer of steel bridge piers, which has good stability, is easy and quick to assemble and disassemble, and can be reused.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: a template casting structure for the protective layer of steel bridge piers, including a template, which is made of wood. The wood template forms a frame on the four sides of the pier base. Multiple secondary beams are vertically fixed to the back of the template. The secondary beams are made of 3*6cm square timber with a spacing of 25cm. The multiple secondary beams are externally fixed to a support frame. The support frame includes two I-beams, tie rods, and steel pipes arranged on each side of the pier base. The two I-beams are the main beams. The two I-beams are arranged vertically and abut against the secondary beams. The two sets of I-beams on opposite sides are locked with four tie rods and two vertically arranged steel pipes at one end of each tie rod. The two sets of I-beams on the other two sides rest on the two fixed sets of I-beams and are fixed by the inner steel pipes.

[0005] Furthermore, the aforementioned formwork casting structure for the protective layer of steel bridge piers also includes a support frame. The support frame is erected around the pier after the protective layer of the steel bridge pier has been cast to a height of 1.6m. The support frame is constructed using a single-row 48-type disc-lock scaffold, with a vertical pole spacing of 1.2m × 0.9m, a horizontal bar spacing of 1.5m, and diagonal braces spaced one span apart. An adjustable base is installed at the bottom of the support frame, which is adjusted according to the site terrain to ensure the support frame is level. The footboard of the boom-launching platform is fully covered and fixed on the top of the support frame, and kickboards are installed around the boom-launching platform. A boom is installed every 5 spans, and its inclination angle is generally controlled between 45° and 60°.

[0006] Furthermore, the top of the template is provided with a flow guide channel, which is a long strip structure with baffles on both sides along the length to form a channel. The lower end is provided with an inverted U-shaped inlay groove that fits into the upper end of the template. Two lifting support columns are hinged to the back of the flow guide channel, and the lower ends of the lifting support columns rest against the ground.

[0007] The beneficial effects of this utility model are as follows: Compared with the prior art, the template structure of this utility model has good stability, ensuring the quality of the poured surface. It has an integrated structure, and each section is formed in one go, ensuring the quality of the poured surface. It is also convenient and quick to assemble and disassemble, and the template can be reused. Attached Figure Description

[0008] Figure 1 A schematic diagram of a construction method for UHPC high-performance concrete in steel bridge piers; Figure 2 A schematic diagram of the wire mesh arrangement structure; Figure 3 This is a schematic diagram of the formwork casting structure used for the protective layer of steel bridge piers; Figure 4 This is a partial top view of the template support frame structure. Figure 5 This is a schematic diagram of the guide channel installation structure; Figure 6 This is a schematic diagram of the flow guide channel structure. Detailed Implementation

[0009] The utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0010] Example 1: As Figures 1-6 As shown, a formwork casting structure for the protective layer of steel bridge piers is provided. The formwork 4 has multiple secondary beams 5 vertically fixed to its back. The secondary beams 5 are made of 3*6cm square timber, spaced 25cm apart. Support frames 6 are externally fixed to the multiple secondary beams 5. The support frames 6 include two I-beams 601 arranged on each side of the pier 2 base, tie rods 602, and steel pipes 603. The two I-beams 601 are the main beams, arranged vertically and abutting against the secondary beams 5. The two sets of I-beams 601 on opposite sides are supported by four tie rods 602 and a single... The tie rod is locked at one end by two vertically arranged steel pipes 603. That is, the two ends of the tie rod 602 are equipped with locking plates 604 and locking nuts 605. The two locking plates 604 are symmetrically abutted against the two steel pipes 603 and the locking nuts 605 are rotated to lock them. In addition, the two sets of I-beams 601 on both sides rest on the two fixed sets of I-beams 601 and are fixed by the inner steel pipes 603. This template structure has good stability, ensuring the quality of the poured surface. It is an integrated structure, formed in one piece, ensuring the quality of the poured surface, and is convenient and quick to assemble and disassemble.

[0011] To facilitate pouring in confined spaces, a flow guide trough 7 is installed on the top of the formwork 4. The flow guide trough 7 is a long strip structure with baffles 701 on both sides along its length to form the trough. An inverted U-shaped inlay groove 702 is located at the lower end, which is inserted into the upper part of the formwork 4 and locked with set screws 708. Two lifting support columns 703 are hinged to the back of the flow guide trough 7, with their lower ends resting on the ground. This structure allows for flow guidance in narrow pouring spaces, facilitating the introduction of concrete into the narrow gap between the formwork and the pier, preventing concrete from falling to the ground and wasting it. In use, the inlay groove of the flow guide trough is inserted into the formwork, the lifting support columns are adjusted to contact the ground for auxiliary support, and the inlay groove is locked with set screws. The outlet of the concrete spray pipe 8 is placed into the inlay groove, and the concrete flows along the flow guide trough into the narrow gap between the formwork and the pier. Because the pouring area is relatively wide, Therefore, it is necessary to move along the length of the guide channel. A chute 704 is set at the top of the outer end of the guide channel 7. A roller assembly 705 is movably inserted into the chute 704. The roller assembly 705 is equipped with at least two rollers. The rollers are rotatably connected to the rotating shaft 706. The rotating shaft 706 is fixedly connected to the wheel frame 707. The top surface of the wheel frame 707 is fixedly connected to the concrete spraying pipe 8 by the binding strap 708. In use, the wheel frame can be moved along the horizontal transverse length of the guide channel to achieve concrete spraying at different positions. This is more conducive to quickly achieving the uniformity of the pouring of the cavity to be poured, avoiding local concrete overflow which would result in less concrete flowing to distant places, thus affecting the pouring efficiency. The chute serves to limit the pulleys and support their movement. Sliding movement is time-saving, labor-saving, easy to operate, and quick to move. The open chute structure of the trough makes it easy to assemble and disassemble the pulley assembly, and it is easy to move to different pier sides for pouring.

[0012] To facilitate formwork erection and pouring, a support system is also included. This system is erected around the perimeter of the steel bridge pier after the protective layer has been poured to a height of 1.6m. The support system uses a single-row, 48-type disc-lock scaffolding, with uprights spaced 1.2m x 0.9m apart, horizontal struts spaced 1.5m apart, and diagonal braces spaced one span apart. Adjustable bases are installed at the bottom of the support system, allowing for adjustments based on the site terrain to ensure levelness. Footboards are fully laid on top of the support system and secured, and kickboards are installed around the platform. Supports are placed every five spans, with the inclination angle generally controlled between 45° and 60°. The operating platform supported by the erected support system allows for the erection of the formwork after the 1.6m pour and the pouring of the second protective layer.

[0013] Example 2: As Figures 1-6 As shown, a construction method for UHPC high-performance concrete in steel bridge piers includes the following steps: Step 1, Base surface cleaning: Clean the base surface of the pier column. Use a high-pressure air gun or blower to thoroughly remove dust, oil, loose materials and other impurities from the base surface of the pier column, ensuring that the base surface is dry and free of stains, and ensuring the adhesion between the high-performance concrete and the pier column. Step 2, Wire Mesh Installation: After the base surface passes inspection, install 25*25mm wire mesh 1. Its specifications and dimensions must be precisely cut according to design requirements. During installation, first unfold wire mesh 1 longitudinally along the pier column 2, and use fixing clamps 3 and binding wires to firmly fix it to the pier column base surface, ensuring a tight fit between the wire mesh and the base surface without loosening or suspension. Overlapping parts of the wire mesh must be connected by binding, with even and firm binding points to meet structural strength and durability requirements. During installation, care must be taken to protect the wire mesh from damage, ensuring its integrity and functionality. Fixing clamps 3 are shear studs, arranged in multiple rows vertically along the pier column 2 base surface, with adjacent rows of shear studs staggered. Binding wires are used to fix the wire mesh 1 to the shear studs, achieving a stable connection and fit between the wire mesh and the pier column base surface.

[0014] Step 3, Template Installation: After the wire mesh installation is accepted, the template installation work is carried out. Wooden templates are used. Before installing the templates, the templates should be inspected to ensure that the template surface is flat, without deformation or damage, and that the joints of the templates are tight and flat, without any leakage of grout. The secondary ribs of the templates are made of 3*6cm square timber with a spacing of 25cm, and the main ribs are made of 2 x 12 I-beams. The template support system should be stable and reliable to ensure that there is no displacement or deformation during the concrete pouring process. After the installation is completed, the templates should be inspected and accepted to ensure that they meet the design requirements and quality standards. The template structure is as follows: Multiple secondary beams 5 are vertically fixed to the back of template 4. These secondary beams 5 are made of 3*6cm square timber, spaced 25cm apart. Support frames 6 are externally fixed to the secondary beams 5. The support frames 6 include two I-beams 601, tie rods 602, and steel pipes 603 arranged on each side of the base of the pier 2. The two I-beams 601 are the main beams, arranged vertically and abutting against the secondary beams 5. The two sets of I-beams 601 on opposite sides are supported by four tie rods 602 and a single tie rod with a single end... The two vertically arranged steel pipes 603 are locked together. Specifically, locking plates 604 and locking nuts 605 are set at both ends of the tie rod 602. The two locking plates 604 are symmetrically abutted against the two steel pipes 603 and the locking nuts 605 are rotated to lock them in place. In addition, the two sets of I-beams 601 on both sides rest on the two fixed sets of I-beams 601 and are fixed by the inner steel pipes 603. This template structure has good stability, ensuring the quality of the poured surface. It is an integrated structure, and each section is formed in one go, ensuring the quality of the poured surface. It is also convenient and quick to assemble and disassemble.

[0015] Step 4, Concrete Mixing and Transportation: The concrete is mixed using a high-performance concrete mixer to ensure uniform mixing and reliable quality. Ingredients should be weighed in advance and prepared according to requirements to avoid waste. During mixing, the designed mix proportions must be strictly followed, and the mixing time and speed must be controlled to ensure the strength and durability of the concrete. The mixed concrete must also undergo quality testing to ensure it meets design requirements. After mixing, the flowability of the freshly mixed UHPC mixture should be measured promptly, and the slump should be controlled between 700mm and 750mm. During the mixing process, pour all the premixed materials into the mixer and start the mixer; add water and shrinkage reducer while mixing; then, add all the steel fibers evenly while mixing, and finally mix until uniform and discharge. Mixing ratio: 2188 kg of premix (HC160), 195 kg of water, 234 kg of steel fiber and 11.0 kg of shrinkage reducer; After the UHPC mixture is mixed, it should be unloaded in batches according to the pouring speed. Do not unload too much at once, as this will lead to loss of fluidity due to untimely pouring, thus affecting the pouring effect and quality. Step 5, Concrete Pouring and Curing: Due to the thinness of the concrete and the narrowness of the pouring space, a diversion channel was used for pouring, combining manual and mechanical methods. During the pouring process, φ8-10 round steel bars were continuously inserted for tamping, and an attached vibrator was used to ensure that the concrete was filled densely without air bubbles or voids. The pouring height was 4.6m. To ensure the quality of the pouring, the pouring was carried out in sections on site, with section heights of 1.6m, 1.5m, and 1.5m. The guide channel 7 is a long strip structure with baffles 701 on both sides along its length to form the channel body. An inverted U-shaped inlay groove 702 is located at the lower end, which is inserted into the upper end of the template 4 and locked with set screws 708. Two lifting support columns 703 are hinged to the back of the guide channel 7, with their lower ends resting on the ground. This structure can guide the concrete flow in narrow pouring spaces, facilitating the introduction of concrete into the narrow gap between the template and the pier, preventing concrete from falling to the ground and causing waste. In use, the inlay groove of the guide channel is inserted into the template, the lifting support columns are adjusted to contact the ground for auxiliary support, and the inlay groove is locked with set screws. The outlet of the concrete spray pipe 8 is placed into the inlay groove, and the concrete flows along the guide channel into the narrow gap between the template and the pier. Because the pouring range is relatively wide, it needs to be moved along the length of the guide channel. A sliding mechanism is provided at the top of the outer end of the guide channel 7. The trough 704 contains a roller assembly 705, which has at least two rollers. The rollers are rotatably connected to a rotating shaft 706, which is fixedly connected to a wheel frame 707. The top surface of the wheel frame 707 is fixedly connected to the concrete spraying pipe 8 via a binding strap 708. In use, the wheel frame can be moved along the horizontal length of the guide trough to achieve concrete spraying at different positions, which is more conducive to quickly achieving uniformity of pouring in the cavity to be poured and avoiding local over-pour of concrete, which would result in less concrete flowing to distant areas and thus affecting pouring efficiency. The trough serves to limit the pulleys and support their movement. It slides along the trough, saving time and effort, and is easy to operate and move quickly. The open trough structure makes it easy to assemble and disassemble the pulley assembly and move it to different pier sides for pouring. The lifting support column 703 adopts a telescopic strut structure, and the bottom is fixedly connected to a flange that connects to the ground.

[0016] After the pouring is completed, the poured surface should be covered and kept moist for curing. When the average temperature is below 15℃, insulation cotton should be used for curing. After the outer formwork is removed, geotextile should be covered and watered for curing. The curing time should not be less than 14 days. This also includes scaffolding erection, which takes place after the 1.6m pour. The total pouring height is 4.6m. The scaffolding is constructed using a 48-type disc-lock single-row scaffolding system, with upright spacing of 1.2m × 0.9m, horizontal bar spacing of 1.5m, and diagonal bracing spaced one span apart. To ensure the stability of the scaffolding, adjustable bases are installed at the bottom and adjusted according to the site terrain to ensure the scaffolding is level. The footboards of the boom-launching platform are fully laid on top of the scaffolding and fixed to ensure the safety of construction personnel. Kickboards are installed around the boom-launching platform to prevent personnel and materials from falling. Outriggers are installed every five spans, with their inclination angle generally controlled between 45° and 60° to ensure effective load transfer and distribution, enhancing the scaffolding's resistance to overturning. When installing outriggers, ensure their connections are firm and reliable, forming a stable triangular support system with the uprights and horizontal members. Furthermore, the material and specifications of the outriggers should meet relevant standards and requirements to ensure their load-bearing capacity and durability. The support structure must pass inspection before it can be put into use.

[0017] The above-mentioned construction method for the protective layer uses formwork casting to achieve a 3cm protective layer. The addition of wire mesh and shear studs during construction can greatly improve the adhesion of the corrosion-resistant protective layer made of UHPC high-performance concrete, improve the stability of the corrosion-resistant protective layer, and ensure better reliability of the protective layer.

[0018] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A formwork casting structure for the protective layer of steel bridge piers, characterized in that: The system includes a wooden template that forms a frame around the base of the pier. Multiple secondary beams are vertically fixed to the back of the template. These secondary beams are made of 3*6cm square timber, spaced 25cm apart. Support frames are externally fixed to these secondary beams. Each support frame consists of two I-beams, tie rods, and steel pipes arranged on each side of the pier base. The two I-beams are the main beams, positioned vertically and resting against the secondary beams. Two sets of I-beams on opposite sides are secured with four tie rods and two vertically arranged steel pipes at one end of each tie rod. The other two sets of I-beams rest on the two fixed sets of I-beams and are secured against the inner steel pipes.

2. The formwork casting structure for the protective layer of steel bridge piers according to claim 1, characterized in that: It also includes a support structure, which is erected around the steel bridge pier column protective layer after it has been poured to a height of 1.6m. The support structure is constructed using a 48-type disc-lock single-row scaffold, with the support uprights spaced 1.2m x 0.9m apart, the horizontal bar spacing 1.5m, and the diagonal braces spaced one span apart. The bottom of the support structure is equipped with an adjustable base, which is adjusted according to the site terrain to ensure that the support structure is level. The footboards of the pole-throwing platform are fully covered and fixed on the top of the support structure, and kickboards are installed around the pole-throwing platform. A pole-throwing support is installed every 5 spans, and its inclination angle is controlled between 45° and 60°.

3. The formwork casting structure for the protective layer of steel bridge piers according to claim 1, characterized in that: The top of the template is equipped with a flow guide channel, which is a long strip structure. Baffles are set on both sides along the length to form the channel. The lower end is equipped with an inverted U-shaped inlay groove that fits into the upper end of the template. Two lifting support columns are hinged to the back of the flow guide channel, and the lower ends of the lifting support columns rest against the ground.

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