A construction method for segmented precast concrete cap beams and its component molds

Abstract

This invention discloses a construction method for segmented precast concrete cap beams and its component molds. The invention uses a combined component mold consisting of a bottom mold, side molds, a first side mold, and a second side mold. Component one and component two are then fabricated using this mold. Component one and component two are then assembled on-site and cast into segmented precast concrete cap beams. This method enables the fabrication of large-cantilever precast cap beams under special working conditions such as narrow construction sites, small spacing between supporting columns, large cantilever sections on both sides, and high stress requirements. Furthermore, because precast concrete cap beams are heavy and difficult to transport, segmenting the construction of component one and component two reduces the difficulty of transportation and hoisting, thus lowering the overall fabrication difficulty of the precast concrete cap beams. Simultaneously, it also allows for the fabrication of larger-sized and heavier precast concrete cap beams, effectively meeting the requirements for precast concrete cap beams in different projects.

Description

Technical Field

[0001] This invention relates to the field of urban elevated bridge girder manufacturing technology, and in particular to a construction method for segmented precast concrete girder and its component molds. Background Technology

[0002] With the rapid development of urban elevated road prefabrication technology, urban elevated roads are mostly produced in factories and then assembled on site, which can effectively improve the construction speed and the level of on-site construction civilization. However, as construction conditions become increasingly complex, traditional integral or segmented prefabricated cap beam technology cannot meet the actual needs of some specific projects. Segmented cap beams can effectively meet the overall stress requirements of large cantilever at both ends of the cap beam, but related efficient production and manufacturing technologies are still lacking. Summary of the Invention

[0003] In view of this, the present invention provides a construction method for segmented precast concrete cap beams and its component molds to solve the technical problems existing in the background art.

[0004] A segmented precast concrete cap beam component mold, the segmented precast concrete cap beam including component one, component two, and a post-cast strip formed in the casting cavity between component one and component two, the component mold including a bottom mold, end molds set at both ends of the bottom mold, and a first side mold and a second side mold set on both sides of the bottom mold, the bottom mold, end molds, first side molds and second side molds together enclose a casting area for casting component one or component two;

[0005] The structure of the bottom mold, end mold, and second side mold used for casting component one is the same as the structure of the bottom mold, end mold, and second side mold used for casting component two.

[0006] The first side mold used for casting component one includes a first mold frame and a first side plate fixed inside the first mold frame. The first mold frame has bent portions at both ends. The end mold is fixed on the bent portions, and there is a first gap between its inner side and the folded surface of the bent portion to form a first outer leaf plate on the inner side of the end of component one. The bottom shape of the first side plate matches the top shape of the bottom mold, and there is a second gap between the bottom edge of the first side plate and the top surface of the bottom mold to form a second outer leaf plate on the inner side of the bottom surface of component one. The first side plate is provided with positioning holes for inserting transverse prestressing tendons.

[0007] The first side mold used for casting component two includes a second mold frame and a second side plate fixed inside the second mold frame. The inner side of the end mold is in contact with the end of the second mold frame, and the bottom edge of the second side plate is in contact with the top surface of the bottom mold. The second side plate is also provided with positioning holes for inserting transverse prestressing tendons.

[0008] Preferably, the structure of the second mold frame is the same as that of the first mold frame, both including a steel frame and side templates fixed inside the steel frame.

[0009] Preferably, the bottom mold includes a bottom template and several bottom mold supports fixed to the bottom of the bottom template, and the shape of the bottom template matches the bottom surface shape of component one and component two.

[0010] Preferably, the shape of the inner surface of the second side mold matches the shape of the outer surface of component one and component two.

[0011] A construction method for segmented precast concrete cap beams specifically includes the following steps:

[0012] S1. The component mold is composed of bottom mold, end mold, first side mold and second side mold used for component one. Component one is manufactured in the factory. After component one is manufactured, the first side mold used for component one is replaced with the first side mold used for component two to manufacture component two. Meanwhile, the pile foundation, pile cap and pier column are constructed at the same time.

[0013] Both the manufactured component one and component two contain transverse prestressed steel strands and longitudinal prestressed steel strands. Component one has a first outer leaf plate formed on the inner side of both ends and a second outer leaf plate formed on the inner side of its bottom surface.

[0014] After component one and component two are fabricated, the first batch of prestressed steel strands in the longitudinal direction on component one and component two are tensioned.

[0015] S2, hoist component one and component two onto the bridge pier column;

[0016] S3, the transverse prestressed steel strands of component one are connected to the transverse prestressed steel strands of component two through the joint reinforcement, and then ultra-high performance concrete is poured into the casting cavity between component one and component two, while the post-cast concrete of the support pad stone and the stop block is completed at the same time.

[0017] S4. After the strength of the ultra-high performance concrete in the pouring cavity between component one and component two reaches 100% of the design strength, the second batch of prestressed steel strands in the longitudinal direction on component one and component two are tensioned.

[0018] S5, tension the transverse prestressed steel strands on component one and component two, then install the precast box girder and tension the third batch of longitudinal prestressed steel strands on component one and component two;

[0019] S6, bridge deck construction completed.

[0020] Preferably, the manufacturing methods of component one and component two in step S1 are the same, both including the following steps:

[0021] S11, Place the bottom formwork on a flat ground, set a positioning plate in the center of the bottom formwork, and set a grouting sleeve on the positioning plate;

[0022] S12, hoist the tied steel cage onto the bottom formwork, and insert longitudinal prestressed corrugated pipes inside the steel cage;

[0023] S13, the first side mold and the second side mold are set on both sides of the bottom mold, and the end mold is set at both ends of the bottom mold. The bottom mold, the end mold, the first side mold and the second side mold together form a casting area.

[0024] S14, a transverse prestressed corrugated pipe is inserted into the positioning hole of the first side formwork, with one end of the prestressed corrugated pipe extending into the steel cage and the other end exposed outside the first side formwork.

[0025] S15 involves pouring ultra-high performance concrete within the pouring area, and then curing the resulting component after the concrete has solidified.

[0026] S16, prestressed steel strands are threaded inside the prestressed corrugated pipes in the longitudinal and transverse directions;

[0027] S17, component demolding.

[0028] Preferably, the specific steps for demolding the component in step S17 are as follows:

[0029] First remove the end mold, then remove the second side mold;

[0030] Then, destroy the side plate of the first side mold;

[0031] Finally, the mold frame of the first side mold is removed.

[0032] Preferably, the specific steps in step S2 of hoisting component one and component two onto the bridge pier column are as follows:

[0033] First, pre-assemble component one and component two;

[0034] Then, component one and component two are transported to the viaduct construction site and hoisted onto the bridge pier columns respectively. The first and second outer leaf plates of component one abut against the inner side of component two.

[0035] Then, grout is injected into the grouting sleeves of component one and component two to connect component one and component two to the pier column.

[0036] Preferably, the specific steps for pre-assembling component one and component two are as follows:

[0037] Fix component one, and lift component two to make it fit against component one;

[0038] After component two is moved to be in contact with component one, one end of component two is fixed to the ground and the other end is slowly lowered. During the process of the other end of component two slowly lowering to a stable contact with the ground, observe whether there is any collision or interference between the transverse prestressed steel strands on component two and the transverse prestressed steel strands on component one. If there is no collision or interference, the pre-assembly of component one and component two is completed; otherwise, adjust the transverse prestressed steel strands on component one or component two.

[0039] Preferably, each time the prestressed steel strand is tensioned, it is tensioned symmetrically, and an initial stress is applied first, and then the tension force is gradually increased to the design value and held for a set time before grouting and anchoring.

[0040] The beneficial effects of this invention are:

[0041] 1. This invention uses a combined component mold consisting of a bottom mold, side molds, a first side mold, and a second side mold to produce component one and component two. Component one and component two are then assembled on-site and cast into segmented precast concrete cap beams. This allows for the production of large-cantilever precast cap beams under special working conditions such as narrow construction sites, small spacing between supporting columns, large cantilever on both sides, and high stress requirements. Furthermore, since precast concrete cap beams are heavy and difficult to transport, segmenting component one and component two reduces the difficulty of transportation and hoisting, thus lowering the difficulty of precast concrete cap beam production. At the same time, it also enables the production of larger-sized and heavier precast concrete cap beams, effectively meeting the requirements for precast concrete cap beams in different projects.

[0042] 2. The construction method of the precast concrete cap beam of the present invention can effectively improve the production efficiency and precision of the components, and can be assembled on the ground or at low altitudes, reducing the time spent on high-altitude operations. At the same time, the construction method of the segmented cap beam can save a lot of auxiliary materials such as formwork and scaffolding, thereby reducing construction costs and construction risks.

[0043] 3. Segmented cap beams can flexibly adapt to different terrains and construction conditions, especially in sites with complex terrain or limited space, where construction is more convenient. At the same time, the construction process of segmented cap beams reduces noise, dust, and wastewater pollution generated during on-site pouring and curing, helping to reduce the negative impact of construction on the surrounding environment and residents, aligning with the concept of modern green building.

[0044] 4. The precast concrete cap beam of this invention is longitudinally divided into three parts: component one, component two, and the post-cast strip. Component one and component two are fabricated separately and prestressed tendons are reserved. After component one and component two are assembled on site, they are connected and displaced by cast-in-place concrete. Compared with segmented precast concrete cap beams, it can achieve greater cantilever force and has a wider range of applications. Moreover, since outer leaf plates are reserved at both ends and the bottom of component one, after component one and component two are spliced ​​and assembled, the outer leaf plates on component one can serve as the side formwork for the subsequent casting of the post-cast strip and form a casting cavity with one side of component two, reducing the formwork work on the construction site, and also enhancing the structural integrity and consistency of the precast concrete cap beam.

[0045] 5. The first side formwork used for both Component 1 and Component 2 is composed of steel frame structure and wooden formwork. The steel frame structure can support the overall shape of the component, while the wooden formwork can accurately position the exposed transverse prestressing tendons. Furthermore, the exposed transverse prestressing tendons on both Component 1 and Component 2 are L-shaped steel bars, which can greatly reduce the difficulty of inserting the longitudinally laid joint steel bars in the intermediate cast-in-place post-cast strip.

[0046] 6. The bottom mold, end mold and second side mold used for component one and component two are the same, only the structure of the first side mold is slightly different. After component one is made, only the first side mold of component one needs to be replaced with the first side mold of component two. The existing bottom mold, end mold and second side mold can be reused, which greatly reduces the mold making cost and the enterprise construction cost. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a structural schematic diagram of a segmented precast concrete cap beam.

[0049] Figure 2 This is a side view of a segmented precast concrete cap beam.

[0050] Figure 3 This is a structural schematic diagram of component one of the components that make up the segmented precast concrete cap beam.

[0051] Figure 4 This is a structural schematic diagram of component two, which makes up the segmented precast concrete cap beam.

[0052] Figure 5 This is a structural diagram of the component mold for making component one or component two.

[0053] Figure 6 This is a schematic diagram of the bottom mold structure.

[0054] Figure 7 This is a schematic diagram of the structure of the first side mold used for casting component one.

[0055] Figure 8 This is a schematic diagram showing the connection between the first side mold and the end mold used for casting component 1.

[0056] Figure 9 This is an enlarged view of the connection between the first side mold and the end mold used in casting component 1.

[0057] Figure 10 This is a schematic diagram of the first side mold used for casting component two.

[0058] Figure 11 This is a structural schematic diagram of the second side mold.

[0059] The meanings of the labels in the diagram are as follows:

[0060] 1 is the bottom formwork, 11 is the bottom template, and 12 is the bottom formwork support.

[0061] 2 is the end model.

[0062] 3 is the first side mold, 31 is the first mold frame, 32 is the first side plate, 33 is the bending section, 34 is the first gap, 35 is the second gap, 36 is the second mold frame, and 37 is the second side plate.

[0063] 4 is the second side mold.

[0064] 5 is component one.

[0065] 6 is component two.

[0066] 7 is the pouring area.

[0067] 8 is the post-pouring strip.

[0068] 9 is the first outer leaf plate.

[0069] 10 is the second outer leaf plate.

[0070] 11 is a segmented precast concrete cap beam.

[0071] 12 are transverse prestressing tendons.

[0072] 13 is the joint reinforcement. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0074] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0075] It should be understood that although the terms first, second, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms and should not be construed as indicating or implying relative importance. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0076] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0077] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0078] To better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings.

[0079] The present invention provides a segmented precast concrete cap beam component mold, including a bottom mold 1, end molds 2 set at both ends of the bottom mold 1, and a first side mold 3 and a second side mold 4 set on both sides of the bottom mold 2. The bottom mold 1, the end molds 2, the first side molds 3 and the second side molds 4 together form a casting area 7 for casting component 1 5 or component 2 6.

[0080] The segmented precast concrete cap beam includes component 5, component 6, and a post-cast strip 8 formed in the casting cavity between component 5 and component 6. Component 5 and component 6 are each cast separately using the component mold composed of bottom mold 1, end mold 2, first side mold 3, and second side mold 4.

[0081] The structure of the bottom mold, end mold and second side mold used for casting component 1 5 is the same as that of the bottom mold, end mold and second side mold used for casting component 2 6, but the structure of the first side mold used for casting component 1 5 is different from that of the first side mold used for casting component 2 6.

[0082] Specifically, the first side mold used for casting component 1 includes a first mold frame 31 and a first side plate 32. The first mold frame 31 is a steel frame structure, and each end of the first mold frame 31 has an inclined bending portion 33. In this embodiment, each end of the first mold frame 31 is bent outward to form an L-shaped bending portion 33. The end mold 2 is vertically fixed on the bending portion 33 and there is a first gap 34 between its inner side and the fold surface of the bending portion. The first gap 34 is used to allow the end of the cast component 1 5 to form a first outer leaf plate 9 extending inward. The first side plate 32 is fixed to the inner side of the first mold frame 31. The plate surface of the first side plate 32 is in contact with the mold surface of the first mold frame 31. The bottom surface shape of the first side plate 32 matches the top surface shape of the bottom mold 1, but the bottom surface of the first side plate 32 does not contact the top surface of the bottom mold 1. There is a second gap 35 between the bottom surface of the first side plate 32 and the top surface of the bottom mold 1. The second gap 35 is used to make the bottom surface of the cast component 5 form a second outer leaf plate 10 extending inward. At the same time, positioning holes for passing through transverse prestressing tendons 12 are opened on the first side plate 32.

[0083] The first side mold used for casting component two includes a second mold frame 36 and a second side plate 37. The second mold frame 36 is also a steel frame structure, and its structural form and dimensions are the same as those of the main steel frame of the first mold frame 31. However, the two ends of the second mold frame 36 do not have bent parts. The end mold 2 is fixed at an angle to the end of the second mold frame 36, and the mold surface of the end mold is perpendicular to the mold surface of the second mold frame 36. The second side plate 37 is fixed to the inner side of the second mold frame 36. The plate surface of the second side plate 37 is in contact with the mold surface of the second mold frame 36. The bottom shape of the second side plate 37 matches the top shape of the bottom mold 1, and the bottom surface of the second side plate 37 is in contact with the top surface of the bottom mold 1. The second side plate 37 is also provided with positioning holes for inserting transverse prestressing tendons.

[0084] In this embodiment, both the first side panel 32 and the second side panel 37 are made of wood.

[0085] The bottom mold 1 includes a bottom template 11 and several bottom mold supports 12 fixed to the bottom of the bottom template 11. The shape of the bottom template 11 matches the bottom surface shape of component one and component two.

[0086] The shape of the inner side of the second side mold 4 matches the shape of the outer side of component 5 and component 6. The shape of the outer side of component 5 is the same as that of the outer side of component 6. The structure of the second side mold 4 is similar to that of the first side mold, which is also a steel frame structure. The inner side of the steel frame structure is covered with steel plates. In this embodiment, since the outer sides of component 5 and component 6 are not flat, that is, the lower part of the outer side of component 5 and component 6 is concave inward compared with the upper part of the outer side and there are multiple rectangular protrusions on the lower part of the outer side, in order to cast this shape, in this embodiment, the inner side of the second side mold 4 is provided with a bend to form a Z-shape on the entire inner side and multiple grooves are correspondingly provided on the lower part of the outer side.

[0087] When the bottom mold 1, end mold 2, first side mold 3, and second side mold 4 are assembled together, a casting area 7 is formed. Concrete is poured into this casting area 7 to obtain component 5 and component 6. Component 6 has the same shape as the main body of component 5, except that the bottom of the inner side of component 5 extends inward with a second outer leaf plate 10, and the two ends of the inner side extend inward with first outer leaf plates 9. When manufacturing the segmented precast concrete cap beam, component 5 and component 6 are aligned. The first outer leaf plate 9 and the second outer leaf plate 10 of component 5 abut against the inner side of component 6, thus forming a casting cavity between component 5 and component 6. The first outer leaf plate 9 and the second outer leaf plate 10 can serve as side molds for the subsequent casting strip 8, reducing on-site formwork work and enhancing the structural integrity and consistency of the cap beam.

[0088] This invention also provides a construction method for segmented precast concrete cap beams, specifically including the following steps:

[0089] S1. The component mold is composed of bottom mold 1, end mold 2, first side mold used for component one and second side mold 4. Component one is manufactured in the factory. After component one is manufactured, the first side mold used for component one is replaced with the first side mold used for component two to manufacture component two.

[0090] During the fabrication of component 1 (5) and component 2 (6), the pile foundation, pile cap, and bridge pier columns are constructed simultaneously.

[0091] The manufacturing methods for component 5 and component 6 are the same, both including the following steps:

[0092] S11. Place the bottom formwork 1 on a flat surface. The bottom formwork 1 must be fixed flat and firmly to prevent movement or structural deformation during subsequent installation of the reinforcing cage and pouring. The bottom formwork should not be moved during subsequent installation of the reinforcing cage and formwork assembly. After the bottom formwork 1 is installed, clean it. Set a positioning plate at the center of the bottom formwork 1, and then install a grouting sleeve on the positioning plate.

[0093] S12, the tied steel cage is hoisted onto the bottom formwork 1, and longitudinal prestressed corrugated pipes are inserted into the steel cage.

[0094] The reinforcing cage should be tied securely according to the design. The welding length of double-sided welds on the reinforcing bars should be 5d, and the welding length of single-sided welds should be 10d. The thickness of the net protective layer of the reinforcing bars should not be less than 25 mm. The ends of the reinforcing bars should be provided with 135° hooks. The stirrup joints of adjacent reinforcing bars should be staggered longitudinally to avoid loosening or deformation during subsequent concrete pouring.

[0095] The positions of the reinforcing cage and longitudinal prestressed corrugated pipes should be accurate to avoid collisions with the mold or other components during subsequent mold closing.

[0096] S13, the first side mold 3 and the second side mold 4 are set on both sides of the bottom mold 1, and the end mold 2 is set at both ends of the bottom mold 1. The bottom mold 1, the end mold 2, the first side mold 3 and the second side mold 4 together form a casting area 7.

[0097] S14. A transverse prestressed corrugated pipe is inserted into the positioning hole of the first side formwork 3. One end of the prestressed corrugated pipe extends into the reinforcing cage, and the other end protrudes outside the first side formwork 3. Embedded parts are installed. The position and quantity of the embedded parts need to meet the design requirements to ensure their position and depth in the concrete and avoid crossing or colliding with the reinforcing cage or other components.

[0098] S15, pour ultra-high performance concrete (UHPC) in pouring area 7, and after the concrete has solidified, cure the resulting component.

[0099] S16. When the component has been cured to the point where its structural strength reaches 100%, prestressed steel strands can be threaded through the prestressed corrugated pipes in the longitudinal and transverse directions.

[0100] S17, component demolding.

[0101] When demolding the component, first remove the end mold 2, then remove the second side mold 4; then, destroy the side plate of the first side mold 3; finally, remove the mold frame of the first side mold 3.

[0102] After component one is manufactured, the first side mold used for component one is replaced with the first side mold used for component two, and component two can be manufactured according to the above method.

[0103] Both the manufactured component one and component two contain transverse prestressed steel strands and longitudinal prestressed steel strands. Component one has a first outer leaf plate 9 formed on the inner side of both ends and a second outer leaf plate 10 formed on the inner side of its bottom surface.

[0104] After components one and two are fabricated, the first batch of prestressed steel strands in the longitudinal direction of components one and two are tensioned. When tensioning the prestressed steel strands, symmetrical tensioning should be performed, with initial stress applied first, and then the tension force gradually increased to the design value and held for a set time before grouting and anchoring. In this embodiment, the first batch consists of four N3 prestressed steel strands. The four N3 prestressed steel strands are tensioned using a double-control symmetrical tensioning method. Initial stress is applied to the four N3 prestressed steel strands first, and then the tension force is gradually increased to the design value and held for a period of time before anchoring. After tensioning, vacuum grouting is used for anchoring. The grouting cement strength is not less than 60 MPa, and a vacuum grouting agent is used during grouting.

[0105] S2, hoist component one and component two onto the bridge pier column.

[0106] Specifically, component one and component two are pre-assembled: component one is fixed, and component two is lifted to fit against component one; after component two is moved to fit against component one, one end of component two is fixed to the ground and the other end is slowly lowered. During the process of the other end of component two slowly lowering to a stable touch with the ground, it is observed whether there is any collision or interference between the transverse prestressed steel strands on component two and the transverse prestressed steel strands on component one. If there is no collision or interference, the pre-assembly of component one and component two is completed; otherwise, the transverse prestressed steel strands on component one or component two are adjusted.

[0107] Then, component one and component two are transported to the viaduct construction site and hoisted onto the bridge pier columns respectively, so that the first outer leaf plate 9 and the second outer leaf plate 10 of component one abut against the inner side of component two. At this time, a casting cavity is formed between component one 5 and component two 6, and the first outer leaf plate 9 and the second outer leaf plate 10 can be used as the side formwork for the subsequent casting of the post-cast strip 8.

[0108] Then, grout is injected into the grouting sleeves of component 5 and component 6 to connect component 5 and component 6 to the pier column.

[0109] S3. Since the transverse prestressing tendons 12 (prestressed steel strands) of component 1 and component 2 are both exposed tendons, the transverse prestressing tendons on component 1 5 and the transverse prestressed steel strands on component 2 6 can be connected by the joint reinforcement 13. Then, ultra-high performance concrete (UHPC) is poured into the casting cavity between component 1 5 and component 2 6 to form the post-cast strip 8, and the post-cast concrete of the support pad stone and the stop block is completed at the same time.

[0110] S4. After the concrete strength of the post-cast strip 8 reaches 100% of the design strength, the second batch of prestressed steel strands in the longitudinal direction on component 5 and component 6 are tensioned. In this embodiment, the second batch of tensioned prestressed steel strands consists of 2 N2 and 4 N4 prestressed steel strands. The 2 N2 and 4 N4 prestressed steel strands are also tensioned using a double-control symmetrical tensioning method. Initial stress is first applied to the 6 prestressed steel strands, and then the tensioning force is gradually increased to the design value. After holding for a period of time, the strands are anchored. After tensioning, vacuum grouting is used for grouting and anchor sealing. The strength of the grouting cement is not less than 60 MPa, and vacuum grouting agent is used during grouting.

[0111] S5, tension the transverse prestressing tendons (prestressed steel strands) on component one and component two, then install the precast box girder and tension the third batch of longitudinal prestressed steel strands on component one and component two. In this embodiment, the third batch tensions 2 N2 and 4 N1 prestressed steel strands, still using double-controlled symmetrical tensioning. Initial stress is applied to the 6 prestressed steel strands first, and then the tension force is gradually increased to the design value and held for a period of time before anchoring. After tensioning, vacuum grouting is used for grouting and anchor sealing. The grouting cement strength is not less than 60MPa, and vacuum grouting agent is used during grouting.

[0112] S6, bridge deck construction completed.

[0113] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A mold for a segmented precast concrete cap beam component, the segmented precast concrete cap beam comprising component one, component two, and a post-cast strip (8) formed in the casting cavity between component one (5) and component two (6), characterized in that, The component mold includes a bottom mold (1), end molds (2) set at both ends of the bottom mold (1), and a first side mold (3) and a second side mold (4) set on both sides of the bottom mold (2). The bottom mold (1), end molds (2), first side molds (3) and second side molds (4) together form a casting area (7) for casting component one (5) or component two (6). The structure of the bottom mold, end mold, and second side mold used for casting component one (5) is the same as the structure of the bottom mold, end mold, and second side mold used for casting component two (6). The first side mold used for casting component one includes a first mold frame (31) and a first side plate (32) fixed inside the first mold frame (31). The first mold frame (31) has bent portions (33) at both ends. The end mold (2) is fixed on the bent portion (33) and there is a first gap (34) between its inner side and the fold surface of the bent portion to form a first outer leaf plate (9) on the inner side of the end of component one (5). The bottom shape of the first side plate (32) matches the top shape of the bottom mold (1) and there is a second gap (35) between the bottom edge of the first side plate (32) and the top surface of the bottom mold (1) to form a second outer leaf plate (10) on the inner side of the bottom surface of component one (5). The first side plate (32) is provided with positioning holes for inserting transverse prestressing tendons. The first side mold used for casting component 2 includes a second mold frame (36) and a second side plate (37) fixed inside the second mold frame (36). The inner side of the end mold (2) is in contact with the end of the second mold frame (36), and the bottom edge of the second side plate (37) is in contact with the top surface of the bottom mold (1). The second side plate (37) is also provided with positioning holes for inserting transverse prestressing tendons.

2. The segmented precast concrete cap beam component mold according to claim 1, characterized in that, The structure of the second mold frame (36) is the same as that of the first mold frame (31), both including a steel frame and side templates fixed inside the steel frame.

3. The segmented precast concrete cap beam component mold according to claim 1, characterized in that, The bottom mold (1) includes a bottom template (11) and several bottom mold supports (12) fixed to the bottom of the bottom template (11). The shape of the bottom template (11) matches the bottom surface shape of component one and component two.

4. The segmented precast concrete cap beam component mold according to claim 1, characterized in that, The shape of the inner side of the second side mold (4) matches the shape of the outer side of component one (5) and component two (6).

5. A construction method for a segmented precast concrete cap beam, characterized in that, Specifically, the following steps are included: S1. The component mold is composed of bottom mold, end mold, first side mold and second side mold used for component one. Component one is manufactured in the factory. After component one is manufactured, the first side mold used for component one is replaced with the first side mold used for component two to manufacture component two. Meanwhile, the pile foundation, pile cap and pier column are constructed at the same time. Both the fabricated component one and component two contain transverse prestressed steel strands and longitudinal prestressed steel strands. Component one has a first outer leaf plate (9) formed on the inner side of both ends and a second outer leaf plate (10) formed on the inner side of its bottom surface. After component one and component two are fabricated, the first batch of prestressed steel strands in the longitudinal direction on component one and component two are tensioned. S2, hoist component one and component two onto the bridge pier column; S3, the transverse prestressed steel strand of component one is connected to the transverse prestressed steel strand of component two through the joint steel bar, and then ultra-high performance concrete is poured into the pouring cavity between component one (5) and component two (6), while the support pad stone and the block post-poured concrete are completed. S4. After the strength of the ultra-high performance concrete in the pouring cavity between component one (5) and component two (6) reaches 100% of the design strength, the second batch of prestressed steel strands in the longitudinal direction on component one and component two are tensioned. S5, tension the transverse prestressed steel strands on component one and component two, then install the precast box girder and tension the third batch of longitudinal prestressed steel strands on component one and component two; S6, bridge deck construction completed.

6. The construction method of the segmented precast concrete cap beam according to claim 5, characterized in that, The manufacturing methods for component one and component two in step S1 are the same, both including the following steps: S11, place the bottom mold (1) on a flat ground, set a positioning plate in the center of the bottom mold (1), and set a grouting sleeve on the positioning plate; S12, the tied steel cage is hoisted onto the bottom formwork (1), and longitudinal prestressed corrugated pipes are inserted into the steel cage; S13, the first side mold (3) and the second side mold (4) are set on both sides of the bottom mold (1), and the end mold (2) is set at both ends of the bottom mold (1). The bottom mold (1), the end mold (2), the first side mold (3) and the second side mold (4) together form a casting area (7). S14, a transverse prestressed corrugated pipe is inserted into the positioning hole of the first side formwork (3), with one end of the prestressed corrugated pipe extending into the steel cage and the other end exposed outside the first side formwork (3); S15, pour ultra-high performance concrete in the pouring area (7), and after the concrete solidifies, perform curing treatment on the formed component. S16, prestressed steel strands are threaded inside the prestressed corrugated pipes in the longitudinal and transverse directions; S17, component demolding.

7. The construction method for segmented precast concrete cap beams according to claim 6, characterized in that, The specific steps for demolding the component in step S17 are as follows: First remove the end mold (2), then remove the second side mold (4); Then, the side plate of the first side mold (3) is destroyed; Finally, the mold frame of the first side mold (3) is removed.

8. The construction method of the segmented precast concrete cap beam according to claim 6, characterized in that, The specific steps for hoisting component one and component two onto the bridge pier column in step S2 are as follows: First, pre-assemble component one and component two; Then, component one and component two are transported to the viaduct construction site and hoisted onto the pier columns respectively. The first outer leaf plate (9) and the second outer leaf plate (10) of component one abut against the inner side of component two. Then, grout is injected into the grouting sleeves of component one and component two to connect component one and component two to the pier column.

9. The construction method of the segmented precast concrete cap beam according to claim 8, characterized in that, The specific steps for pre-assembling component one and component two are as follows: Fix component one, and lift component two to make it fit against component one; After component two is moved to be in contact with component one, one end of component two is fixed to the ground and the other end is slowly lowered. During the process of the other end of component two slowly lowering to a stable contact with the ground, observe whether there is any collision or interference between the transverse prestressed steel strands on component two and the transverse prestressed steel strands on component one. If there is no collision or interference, the pre-assembly of component one and component two is completed; otherwise, adjust the transverse prestressed steel strands on component one or component two.

10. The construction method of the segmented precast concrete cap beam according to claim 5, characterized in that, Each time the prestressed steel strands are tensioned, they are tensioned symmetrically. Initial stress is applied first, and then the tension is gradually increased to the design value and held for a set time before grouting and anchoring.

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