Large-size cover plate prestress rapid construction process

Abstract

The application relates to the technical field of building construction, in particular to a large-size cover plate prestress rapid construction process, which comprises the following steps: S1, designing a cover plate structure meeting prestress requirements, and erecting a cover plate concrete formwork; S2, preparing a base steel structure according to a design scheme and arranging prestress anchorage devices; S3, arranging prestress steel bars in the cover plate concrete formwork; S4, tensioning the prestress steel bars and applying prestress; S5, pouring concrete and ensuring that the concrete sufficiently fills the gaps between the prestress steel bars; and S6, solidifying the concrete and removing the formwork, thereby completing the prestress rapid construction of the large-size cover plate. The application further discloses a prestress anchorage device for the large-size cover plate prestress rapid construction process, which can improve construction efficiency; the process adopts prestress technology and an efficient construction method, can complete the construction of the large-size cover plate in a short time, greatly shortens the construction period, and improves the construction efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of concrete structure construction, specifically to a rapid prestressed construction process for large-size cover plates. Background Technology

[0002] Vehicle depot developments typically involve large-area roof slabs, with single-side lengths often exceeding 200 meters. Therefore, ultra-long concrete structures are a defining characteristic of such developments. Appropriately increasing the spacing of expansion joints can optimize the building's spatial layout. Currently, first-floor leakage in vehicle depot roof projects is mainly due to two reasons: firstly, the failure of waterproofing at expansion joints; and secondly, shrinkage cracks, or even through-cracks, in the structural slabs during construction. Reducing the number of expansion joints can help prevent waterproofing failure, but it also introduces the problem of shrinkage in the ultra-long concrete roof slabs.

[0003] The concrete beams of vehicle depot cover slabs typically have large spans, with 1-2m of soil cover on top. The heavy load, coupled with temperature stress from the excessive length of the structure, easily leads to cracking of the concrete beams and slabs in the cover layer. Furthermore, the structure below the cover layer is constructed earlier than the upper building and has a longer service life. Therefore, to improve the durability of the vehicle depot cover structure, the concrete crack grade should be appropriately increased. For the beams and slabs of the cover layer, the crack grade should be controlled within 0.1mm, referring to Clause 3.4.5 of the "Code for Design of Concrete Structures" (GB50010-2010), based on the specific project's external environment and service life requirements.

[0004] To meet crack control requirements, if designed as a conventional reinforced concrete structure, a significant amount of ordinary steel reinforcement is needed to control cracking in the beams. The components passively resist temperature stress and deformation, with limited effectiveness. However, by employing prestressed concrete structures, the prestressing tendons apply prestress to the concrete components through pre-compression, offsetting all or part of the tensile stress generated by vertical loads and temperature changes. Therefore, prestressed structures are more effective in reducing the generation and development of cracks in concrete components and improve the durability of concrete structures. However, current prestressed cap slab construction techniques are complex and can easily delay the construction schedule. Summary of the Invention

[0005] The purpose of this invention is to provide a rapid construction process for prestressed large-size cover plates to solve the problems mentioned in the background art.

[0006] To achieve this objective, the present invention provides the following technical solution: a rapid prestressed construction process for large-size cover plates, which includes the following steps:

[0007] S1: Design a cover plate structure that meets the requirements of prestressing and construct the cover plate concrete formwork;

[0008] S2: Prepare the foundation steel reinforcement structure and install prestressed anchorages according to the design plan;

[0009] S3: Arrange prestressed steel bars in the cover plate concrete formwork;

[0010] S4: Tensioning prestressed steel bars to apply prestress;

[0011] S5: Pour concrete and ensure that the gaps between the prestressed steel bars are fully filled;

[0012] S6: Solidify the concrete and remove the formwork to complete the prestressed rapid construction of the large-size cover plate.

[0013] Preferably, the prestressed anchorage is provided in two types: a formwork fixing anchorage and a rebar fixing anchorage. The formwork fixing mold is fixed in the concrete formwork by casting. The rebar fixing anchorage is provided with a quick connector and is connected to the foundation rebar structure through the quick connector.

[0014] Preferably, the method for constructing the concrete formwork for the cover plate is as follows:

[0015] A1: First, excavate and level the foundation, then set up the bottom formwork of the slab, and then build a steel reinforcement cage around it;

[0016] A2: Then, the steel reinforcement cage is used to pour the surrounding slab at the edge of the bottom formwork, and the formwork fixing anchor is fixed in it.

[0017] Preferably, the tensioning of prestressed steel bars is accomplished using prestressing equipment and tensioning tools.

[0018] Preferably, the arrangement of prestressed steel bars before concrete pouring is determined according to the design scheme, and the accurate position and spacing of the prestressed steel bars are ensured. The spacing of the prestressed steel bars is 50-150cm.

[0019] Preferably, the curing steps of the cover plate include curing promotion and strength testing, removing the formwork after the concrete has reached sufficient strength, and trimming and surface treatment of the cover plate.

[0020] Preferably, during the pouring process in step S5, the anchorage is first sealed with micro-expansion cement mortar, and the anchorage position is vibrated during the pouring process.

[0021] A prestressed anchor for rapid prestressed construction of large-size cover plates is disclosed. The prestressed anchor includes an anchor seat, on which a positioning element and a reinforcing bar sleeve are provided. A central rod is fixedly connected to the anchor seat, and an end plate is provided on the central rod. A support block is provided on the end plate. A double-rebound structure is provided on the central rod. The double-rebound structure includes a movable seat that is slidably installed, and a first spring is fixedly connected to the movable seat. A clamping screw is connected to the end plate, and a lifting and lowering rebound structure is provided on the movable seat.

[0022] Preferably, the lifting and retraction structure includes a pad block inserted into the movable seat via an inclined insert rod, and a mounting screw is fixedly connected to the movable seat. A push frame is sleeved on the mounting screw, and a nut is installed on the mounting screw.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. This invention can improve construction efficiency. The process adopts prestressed technology and efficient construction methods, which can complete the construction of large-size cover plates in a short time, greatly shortening the construction period and improving construction efficiency. Due to the shortened construction time, the use of manpower and equipment resources is reduced, thereby reducing construction costs.

[0025] 2. The process of the present invention can improve the structural strength and stability. By tensioning and applying prestress to the prestressed steel bars, the large-size cover plate has better bending and tensile strength, thereby improving the strength and stability of the structure.

[0026] 3. The prestressing equipment and tools used in the process of this invention can assist in completing the operation of tensioning steel bars and applying prestress, simplifying the construction process, reducing construction difficulty, and ensuring the quality and appearance of the cover plate by accurately arranging prestressed steel bars, fully filling the gaps between steel bars, curing concrete and edge finishing treatment, thereby improving the safety of construction.

[0027] 4. When the prestressed anchorage with adjustable prestress is used, the steel bars on it can retain a certain adjustable length after the prestress is applied. Subsequently, the prestress of the steel bars can be adjusted as needed, so that the steel bar structure can be optimized. Attached Figure Description

[0028] Figure 1 This is a first schematic diagram of the anchor structure of the present invention.

[0029] Figure 2 This is a second schematic diagram of the anchor structure of the present invention.

[0030] Figure 3 This is a schematic diagram of the dual callback structure of the present invention.

[0031] Figure 4 This is a schematic diagram of the lifting and lowering callback structure of the present invention.

[0032] In the diagram: 1. Anchor seat; 2. Positioning component; 3. Rebar sleeve; 4. Center rod; 5. End plate; 6. Support block; 7. Movable seat; 8. First spring; 9. Clamping screw; 10. Pad block; 11. Inclined insert rod; 12. Push frame; 13. Mounting screw; 14. Nut. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention provides a technical solution: The technical solution of this patent will be further described in detail below with reference to specific embodiments.

[0035] An implementation method for a rapid prestressed construction process for large-size cover plates includes the following steps:

[0036] S1: Design a cover plate structure that meets prestressing requirements and construct the cover plate concrete formwork. The construction method for the cover plate concrete formwork is as follows:

[0037] A1: First, excavate and level the base to ensure it is flat and stable.

[0038] A2: Then, set up the bottom formwork of the slab and build a steel reinforcement frame around it to provide support and strength for the cover plate.

[0039] A3: Next, pour concrete at the edge of the bottom formwork and fix the formwork anchors therein to ensure the stability and accurate positioning of the formwork.

[0040] S2: Prepare the foundation steel reinforcement structure and install prestressed anchorages according to the design plan. Prestressed anchorages include formwork fixing anchorages and steel reinforcement fixing anchorages. Formwork fixing anchorages are fixed in the concrete formwork by pouring concrete, while steel reinforcement fixing anchorages are connected to the foundation steel reinforcement structure through quick-connect fittings.

[0041] S3: Arrange the prestressed steel bars in the cover slab concrete formwork. Determine the exact position and spacing of the prestressed steel bars according to the design plan. The spacing of the prestressed steel bars is generally in the range of 50-150cm.

[0042] S4: Using prestressing equipment and tensioning tools, tension the prestressed steel bars to apply prestress. Ensure the prestressed steel bars reach the required prestress level to enhance the strength and stability of the cover plate.

[0043] S5: Pour concrete, ensuring that the gaps between the prestressed steel bars are fully filled. During the pouring process, first use micro-expansion cement mortar to seal the anchorage positions, and then properly vibrate the concrete to ensure its density and quality.

[0044] S6: Curing the concrete and removing the formwork completes the rapid prestressed construction of the large-size cover slab. After the concrete reaches sufficient strength, curing-promoting measures are implemented, such as insulation and wet curing. Then, the formwork is removed, and the cover slab is edge-trimmed and surface-treated to ensure construction quality and aesthetics.

[0045] Example 1

[0046] Taking a specific large-size prestressed rapid construction project of a cover plate as an example, the project includes the following steps:

[0047] Design a cover plate structure that meets the requirements of prestressing, and determine the cover plate size and load requirements according to the project needs.

[0048] Erect the concrete formwork for the cover slab, and set up the bottom formwork and steel reinforcement cage according to the design plan.

[0049] Prepare the foundation steel reinforcement structure and install prestressed anchorages, including formwork fixing anchorages and steel reinforcement fixing anchorages.

[0050] According to the design plan, prestressed steel bars are arranged in the concrete formwork at predetermined intervals and positions.

[0051] Prestressing equipment and tensioning tools are used to tension the prestressed steel bars, apply prestress, and ensure that the prestressed steel bars reach the required prestress level.

[0052] Pour concrete to ensure that the gaps between the prestressed steel bars are fully filled, and use micro-expansion cement mortar to seal the anchorage positions during the pouring process.

[0053] Implement concrete curing promotion measures, such as heat preservation and wet curing, to promote concrete curing and strength development.

[0054] After the concrete reaches sufficient strength, the formwork is removed, and the edges of the cover plate are trimmed and the surface is treated to complete the prestressed rapid construction of the large-size cover plate.

[0055] This embodiment illustrates the process of completing a large-size cover plate using the prestressed rapid construction technology. Through prestressing technology and efficient construction methods, construction efficiency is improved, construction costs are reduced, and construction quality and safety are guaranteed.

[0056] A prestressed anchor for rapid prestressed construction of large-size cover plates includes an anchor seat 1, a positioning element 2 and a reinforcing bar sleeve 3 on the anchor seat 1, a central rod 4 fixedly connected to the anchor seat 1, an end plate 5 on the central rod 4, a support block 6 on the end plate 5, a double-rebound structure on the central rod 4, the double-rebound structure including a movable seat 7 slidably installed, a first spring 8 fixedly connected to the movable seat 7, a clamping screw 9 connected to the end plate 5, and a lifting and lowering rebound structure on the movable seat 7.

[0057] The lifting and retraction structure includes a pad 10 that is inserted into the movable seat 7 via an inclined insert rod 11, and a mounting screw 13 is fixedly connected to the movable seat 7. A push frame 12 is sleeved on the mounting screw 13, and a nut 14 is installed on the mounting screw 13.

[0058] When using the prestressed anchorage of this invention, the anchorage seat 1 is first fixed to the foundation steel reinforcement structure by the positioning member 2. Then, the steel reinforcement is passed through the steel reinforcement sleeve 3 and connected through the pad block 10 and the support block 6, thus generating a certain degree of bending. After applying prestress tension, a certain adjustable length can still be retained. Subsequently, the prestress of the steel reinforcement can be adjusted as needed. Furthermore, this invention is equipped with a double adjustment structure. On the one hand, the movable seat 7 can be pushed by rotating the clamping screw 9 on the end plate 5, which, in conjunction with the first spring 8, achieves adjustment. From the perspective of the function of the movable seat 7, since the movable seat 7 is located between the end plate and the rebar sleeve 3, the rebar passes through the movable seat 7. When the position of the movable seat 7 is adjusted, different magnitudes of thrust can be generated by the pad 10 to change the magnitude of the prestress on the rebar. Similarly, the nut 14 can be moved on the mounting screw 13 to apply thrust to the push frame 12. By pushing the push frame 12 along the inclined plane of the inclined insert rod 11, the position of the pad 10 can be adjusted, further changing the magnitude of the thrust of the pad 10 on the rebar, adjusting the prestress of the rebar, so that the rebar structure can be optimized.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A rapid construction process for prestressed large-size cover plates, characterized in that: The construction process includes the following steps: S1: Design a cover plate structure that meets the requirements of prestressing and construct the cover plate concrete formwork; S2: Prepare the foundation steel reinforcement structure and install prestressed anchorages according to the design plan; S3: Arrange prestressed steel bars in the cover plate concrete formwork; S4: Tensioning prestressed steel bars to apply prestress; S5: Pour concrete and ensure that the gaps between the prestressed steel bars are fully filled; S6: Solidify the concrete and remove the formwork to complete the prestressed rapid construction of the large-size cover plate; The prestressed anchor includes an anchor seat (1), and the anchor seat (1) is provided with a positioning component (2) and a steel bar sleeve (3). A central rod (4) is fixedly connected to the anchor seat (1), and an end plate (5) is provided on the central rod (4). A support block (6) is provided on the end plate (5). A double-rebound structure is provided on the central rod (4). The double-rebound structure includes a slidingly installed movable seat (7), and a first spring (8) is fixedly connected to the movable seat (7). A clamping screw (9) is connected to the end plate (5). A lifting and lowering rebound structure is provided on the movable seat (7). The lifting and retraction structure includes a pad (10) inserted into the movable seat (7) via a slanted insert rod (11), and a mounting screw (13) is fixedly connected to the movable seat (7). A pusher (12) is sleeved on the mounting screw (13), and a nut (14) is installed on the mounting screw (13).

2. The rapid construction process for prestressed large-size cover plates according to claim 1, characterized in that: There are two types of prestressed anchorages: formwork fixing anchorages and rebar fixing anchorages. The formwork fixing anchorages are fixed in the concrete formwork by casting. The rebar fixing anchorages are equipped with quick connectors and are connected to the foundation rebar structure through the quick connectors.

3. The rapid construction process for prestressed large-size cover plates according to claim 2, characterized in that: The method for constructing the concrete formwork for the cover plate is as follows: A1: First, excavate and level the foundation, then set up the bottom formwork of the slab, and then build a steel reinforcement cage around it; A2: Then, the steel reinforcement cage is used to pour the surrounding slab at the edge of the bottom formwork, and the formwork fixing anchor is fixed in it.

4. The rapid construction process for prestressed large-size cover plates according to claim 1, characterized in that: The tensioning of prestressed steel bars is accomplished using prestressing equipment and tensioning tools.

5. The rapid construction process for prestressed large-size cover plates according to claim 1, characterized in that: The arrangement of prestressed steel bars before concrete pouring is determined according to the design plan, ensuring the accurate position and spacing of the prestressed steel bars. The spacing of the prestressed steel bars is 50-150cm.

6. The rapid construction process for prestressed large-size cover plates according to claim 1, characterized in that: The curing process for the cover plate includes curing acceleration and strength testing. After the concrete reaches sufficient strength, the formwork is removed, and the cover plate undergoes edge trimming and surface treatment.

7. The rapid construction process for prestressed large-size cover plates according to claim 1, characterized in that: In step S5, when pouring, the anchorage is first sealed with micro-expansion cement mortar, and the anchorage position is vibrated during pouring.

Images