Construction method of prefabricated cover beam air bag core mold

Abstract

The invention provides a construction method for an air bag core mold of a prefabricated cover beam. The construction method comprises the following steps that the air bag core mold is positioned and installed on a treated bottom mold; the bent cap steel bar structure is integrally hoisted in place; a bent cap side mold is installed, and an embedded part is arranged; the air bag core mold is inflated to expand to form a bent cap concrete cavity; and concrete is poured, and after the concrete is finally set, the air bag core mold is deflated and dismounted. The air bag is adopted as an inner film to construct the cover beam, the air bag core mold can be rapidly mounted and dismounted, the construction time is greatly saved, and the construction efficiency is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of cap beam construction, and in particular to a method for constructing a prefabricated cap beam airbag core mold. Background Art

[0002] The cap beam is a beam installed on the top of the bridge pier to support, distribute and transfer the load of the superstructure. It is also called a cap beam. A beam made of reinforced concrete or less reinforced concrete is installed on the pier (platform) or on the pile row.

[0003] Cap beams are commonly used on bridge piers. Existing practices include cast-in-place construction, integral prefabricated solid structures, or segmental prefabricated assembly construction. Cast-in-place construction is to set up supports and formwork on site, tie steel bars on them and pour concrete. After the concrete structure reaches the required strength, the supports and formwork are removed. There are many processes and the construction period is as long as dozens of days. Steel formwork is generally used as the core formwork of the prefabricated cap beam. The core formwork in the prior art is generally composed of three to four steel formworks, which are connected to the bottom formwork. In order to facilitate the operators to enter and remove the core formwork from under the bottom formwork, the cap beam prefabricated pedestal is generally set higher. However, the steel formwork disassembly process is relatively complicated. Due to the presence of embedded steel bars on the top of the hole, the operators can only remove the core formwork from under the bottom formwork, and the pedestal has to be set as high as possible. However, this also increases the safety risk of removing the core formwork, and the falling of the core formwork can easily cause an object impact accident. Summary of the invention

[0004] The purpose of this application is to provide a method for constructing a prefabricated cap beam airbag core mold, which has the advantages of simple construction and safe disassembly.

[0005] In order to achieve the above objectives, this application provides the following technical solutions: A method for constructing a prefabricated cap beam airbag core mold comprises the following steps: Positioning and installing the airbag core mold on the processed bottom mold; Lift the cap beam reinforcement structure into place as a whole; Install the cap beam side formwork and set embedded parts; Inflate the airbag core mold to expand and form a cap beam concrete cavity; Pour concrete, and after the concrete has finally set, deflate the airbag core mold and remove the airbag core mold.

[0006] Further configuration: before installing the airbag core mold, the airbag core mold is tested for air leakage, and after confirming that the airbag core mold has no air leakage, the airbag core mold is installed at a preset position of the bottom mold, and the longitudinal seam of the airbag core mold is arranged upward.

[0007] It is further arranged that the joints of the cap beam reinforcement structure are all arranged toward the outside of the cap beam reinforcement structure to avoid contact between the joints of the cap beam reinforcement structure and the airbag core mold when the cap beam reinforcement cage is hoisted into place.

[0008] It is further configured that a fixing rubber plate is provided on the outer periphery of the airbag core mold.

[0009] Further configuration: the airbag core mold is inflated by connecting the air valve of the airbag core mold through the inflation device, and the airbag core mold is fixed to the cap beam steel bar structure by positioning hoop steel bars or cable ties around it.

[0010] Further configuration: before pouring concrete, a release agent is applied to the outer side of the airbag core mold, the inner side of the bottom mold and the inner side of the side mold.

[0011] Further setting: When pouring the cap beam concrete, pour from the center of the cap beam to both ends; pour the material in layers, and use inserted vibrating rods to vibrate in layers.

[0012] Further arrangement: an inserted vibrating rod is used to vibrate simultaneously from both sides of the cap beam, and there is no contact between the inserted vibrating rod and the airbag core mold.

[0013] Further setting: after the concrete is poured and cured to the target strength, the airbag core mold is deflated, and then the airbag is removed from the poured cap beam by gently pulling and slowly pulling.

[0014] Further configuration: the surface of the disassembled airbag core mold needs to be cleaned, and a protective agent is applied to the cleaned airbag surface.

[0015] Compared with the prior art, the solution of this application has the following advantages: 1. In the prefabricated cap beam airbag core mold construction method involved in the present application, an airbag is used as an inner membrane to construct the cap beam, and the airbag core mold can be quickly installed and disassembled, which greatly saves construction time and effectively improves construction efficiency.

[0016] 2. Compared with traditional formwork support and concrete construction methods, the prefabricated cap beam airbag core mold construction method involved in this application has a low cost of the airbag core mold. By setting different airbag shapes, the construction of different inner cavities of the cap beam can be achieved. The operation is simple and can be used multiple times, which greatly reduces the construction cost.

[0017] 3. In the construction method of the prefabricated cap beam airbag core mold involved in the present application, the use of the airbag core mold can further ensure the quality of the prefabricated cap beam. The airbag core mold can form uniform pressure during the concrete pouring process, which helps to reduce cracks in the concrete and improve the compressive resistance of the concrete.

[0018] 4. In the construction method of the prefabricated cap beam airbag core mold involved in the present application, the surface of the airbag core mold removed from the completed cap beam is cleaned in time, and a protective agent can be applied on the surface of the cleaned airbag core mold. The airbag core mold is placed in a ventilated and dry place to avoid contact with corrosive substances such as oils, acids, and alkalis to facilitate recycling.

[0019] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 This is a process flow chart of the construction method of the prefabricated cap beam airbag core mold for this application. DETAILED DESCRIPTION

[0021] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present application.

[0022] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0023] The term "including" and its variations used herein are open inclusions, i.e., "including but not limited to". The term "connected" may be directly connected or indirectly connected through intermediate components (elements). The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0024] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish between devices, modules or units, and are not used to limit these devices, modules or units to be different devices, modules or units, nor are they used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0025] In response to the current problem of difficulty in dismantling steel formwork during cap beam construction, the present application provides a method for constructing an airbag core mold for a prefabricated cap beam, which uses an airbag as the core mold for the prefabricated cap beam. It has the advantages of fast construction speed, low cost, convenient construction, guaranteed construction quality and strong adaptability. It simplifies the core mold structure of the prefabricated cap beam and can reduce the safety risks of dismantling the steel formwork.

[0026] Specifically, see Figure 1 The prefabricated cap beam airbag core mold construction method of the present application comprises the following steps: First, position and install the airbag core mold on the processed base mold.

[0027] In this embodiment, compressed air or other tools are used to remove debris, dust, etc. in the bottom mold to ensure that the bottom mold surface is clean and free of dirt, improve the bonding force between the concrete and the bottom mold, and ensure the appearance quality of the cap beam concrete surface. At the same time, it is also necessary to check the flatness and elevation of the bottom mold, determine the axis and elevation of the cap beam through measurement and setting out, and use tools such as automatic leveling to accurately control the elevation of the bottom mold to ensure that the bottom mold elevation is within the design allowable range, which helps to ensure the dimensional accuracy and overall quality of the cap beam.

[0028] Before installing the airbag core mold, check whether the airbag core mold has air leakage or damage to ensure its integrity and sealing to avoid leakage during the subsequent concrete pouring process. Install the airbag core mold at the target position of the bottom mold with the longitudinal seam of the airbag core mold facing upward to reduce the friction between the longitudinal seam and the concrete. At the same time, the longitudinal seam facing upward can also facilitate construction personnel to observe and inspect, ensuring that the airbag core mold maintains the correct position and state during the pouring process, thereby further improving the construction quality.

[0029] Subsequently, the cap beam reinforcement structure was hoisted into place as a whole.

[0030] The bottom formwork steel bars of the cap beam are pre-installed on the bottom formwork, and the airbag core formwork is installed on the bottom formwork. After the side plate steel bars are tied, they are hoisted onto the bottom formwork steel bars by a crane and connected to the bottom formwork steel bars to form a complete steel cage. The joints of the cap beam steel bar structure are all arranged toward the outside of the cap beam steel bar structure to avoid contact between the airbag core formwork located in the cap beam steel bar structure and the joints of the cap beam steel bar structure, so as to avoid being punctured by the joints and causing leakage of concrete in the subsequent pouring.

[0031] Next, install the cap beam side formwork and set the embedded parts.

[0032] The side formwork of the cap beam includes vertical supports and transverse plates, which work together to shape the side of the cap beam and ensure the geometric size and stability of the cap beam during concrete pouring. Anchor bars, steel beams, and expansion cement prestressed bars can be embedded in the cap beam to improve the construction quality and structural safety of the bridge cap beam.

[0033] The airbag core mold is inflated to expand and form a cap beam concrete cavity.

[0034] A fixed rubber plate is provided on the outside of the airbag core mold, which can prevent the airbag core mold from being over-inflated and deformed and invading the cap beam concrete to affect the size of the reserved hole. At the same time, the fixed rubber plate can also serve as a sealing layer of the airbag core plate to ensure that the airbag core layer maintains a stable shape and pressure during the inflation process, thereby improving the reliability of the airbag core mold.

[0035] The airbag core mold is inflated by connecting the air valve of the airbag core mold with the air inflation device. The airbag core mold can be inflated by using an air compressor or a manual air pump. When inflating, it is necessary to be careful not to over-pressurize the core mold to avoid damage to the core mold due to excessive inflation pressure. In addition, since the core mold may float or move left and right during the concrete pouring process, the present embodiment needs to be fixed to the cap beam steel structure by positioning hoop steel bars or tie bands around the core mold to ensure the stability of the core plate during the concrete pouring process and the inner cavity forming quality of the cap beam.

[0036] Before pouring concrete, a release agent is applied to the outer side of the airbag core mold, the inner side of the bottom mold, and the inner side of the side mold. The release agent can form an isolation film on the template that is separated from the concrete surface, so that the template can be easily separated from the concrete surface after pouring concrete without affecting the finish of the concrete surface. The release agent in this embodiment can be selected from different concrete release agents such as pure oil release agent, emulsified oil release agent, saponified oil release agent, paraffin release agent, chemically active release agent, and synthetic resin release agent according to the on-site construction environment and usage needs.

[0037] After the formwork and the steel structure are installed, the concrete can be poured. The concrete of this application is first mixed centrally at a mixing station and then transported to the construction site by a concrete tanker. When pouring the cap beam concrete, pour from the center of the cap beam to both ends to avoid the uneven phenomenon caused by pouring from both ends of the cap beam to the center, and cut the material in layers, and the thickness of each layer is not greater than the set value. The set value of the pouring thickness of each layer in this embodiment is 30cm. At the same time, use an inserted vibrator to vibrate in layers to ensure that the concrete is dense and uniform. When vibrating the upper layer of concrete, it is necessary to insert the lower layer of concrete to a certain depth (such as 5~10cm) to ensure that the interlayer concrete is well bonded. In addition, this embodiment also needs to strengthen the vibration of the concrete on the top of the airbag core mold to reduce the loose concrete around the top of the airbag core mold, but it should be noted that when vibrating the concrete on the top of the airbag core mold, avoid the vibration rod from contacting the airbag core mold and causing damage to the airbag core mold. In the process of pouring concrete, it is also necessary to observe the position and state of the airbag core mold in real time to ensure the inner cavity shape of the cap beam.

[0038] After the cap beam concrete is poured, the concrete needs to be cured. Different curing methods should be selected according to the specific climatic conditions, concrete materials and engineering requirements of the construction to ensure the quality and stability of the concrete. For example, watering can be used for curing. After the concrete is initially set, water is evenly sprayed on the concrete surface to keep the surface moist, prevent the concrete surface from drying out prematurely, and thus avoid problems such as cracking. After the concrete solidifies to the target strength, that is, when the concrete strength reaches a strength value between 30MPa and 35MPa, the airbag core mold can be deflated and disassembled.

[0039] In this embodiment, the exhaust valve of the airbag core mold can be opened to achieve rapid exhaust, and then the airbag core mold is removed from the cast cap beam by gently pulling and slowly pulling to avoid damage to the airbag when pulling the airbag core mold. The surface of the removed airbag core mold should be cleaned in time, and a protective agent can be applied to the surface of the cleaned airbag core mold. The airbag core mold should be placed in a ventilated and dry place to avoid contact with corrosive substances such as oil, acid, and alkali, so as to facilitate recycling.

[0040] In summary, the airbag core mold construction method of the prefabricated cap beam of the present application uses airbags as the inner membrane to construct the cap beam. The airbag core mold can be quickly installed and disassembled, which greatly saves construction time and effectively improves construction efficiency. Compared with traditional formwork support and concrete construction methods, the cost of the airbag core mold is low. By setting different airbag shapes, the construction of different inner cavities of the cap beam can be achieved. The operation is simple and can be used repeatedly, which greatly reduces the construction cost. The use of the airbag core mold can further ensure the quality of the prefabricated cap beam. The airbag core mold can form uniform pressure during the concrete pouring process, which helps to reduce cracks in the concrete and improve the compressive resistance of the concrete.

[0041] In addition, the airbag core mold is usually synthesized from chloroprene rubber, natural rubber and nylon cloth in advance, and then made by vulcanization process. It has strong expansion and pressure resistance, as well as elasticity and flexibility, high temperature resistance and good detachability, so that the airbag core mold can adapt to the construction environment under different conditions. For example, the material will not change within different temperature ranges (-10℃~+90℃), and it has strong adaptability.

[0042] The above description is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for constructing a prefabricated cap beam airbag core mold, characterized in that: The following steps are involved: Positioning and installing the airbag core mold on the processed bottom mold; Lift the cap beam reinforcement structure into place as a whole; Install the cap beam side formwork and set embedded parts; Inflating the airbag core mold to expand and form a cap beam concrete cavity; Pour concrete, and after the concrete has finally set, deflate the airbag core mold and remove the airbag core mold.

2. The method for constructing a prefabricated cap beam airbag core mold according to claim 1, characterized in that: Before installing the airbag core mold, the airbag core mold is tested for air leakage. After confirming that the airbag core mold has no air leakage, the airbag core mold is installed at a preset position of the bottom mold, with the longitudinal seam of the airbag core mold facing upward.

3. The method for constructing a prefabricated cap beam airbag core mold according to claim 1, characterized in that: The joints of the cap beam reinforcement structure are all arranged toward the outside of the cap beam reinforcement structure to avoid contact between the joints of the cap beam reinforcement structure and the airbag core mold when the cap beam reinforcement cage is hoisted into place.

4. The method for constructing a prefabricated cap beam airbag core mold according to claim 3, characterized in that: A fixing rubber plate is arranged on the outer periphery of the airbag core mold.

5. The method for constructing the prefabricated cap beam airbag core mold according to claim 3 is characterized in that: The airbag core mold is inflated by connecting the air valve of the airbag core mold through the inflation device, and the four sides of the airbag core mold are fixed to the cap beam steel bar structure by positioning hoop steel bars or cable ties.

6. The method for constructing a prefabricated cap beam airbag core mold according to claim 1, characterized in that: Before pouring concrete, apply release agent on the outside of the airbag core mold, the inside of the bottom mold and the inside of the side mold.

7. The method for constructing a prefabricated cap beam airbag core mold according to claim 1, characterized in that: When pouring cap beam concrete, pour from the center of the cap beam to both ends; pour in layers and vibrate in layers using an inserted vibrator.

8. The method for constructing the prefabricated cap beam airbag core mold according to claim 7, characterized in that: An inserted vibrating rod is used to vibrate simultaneously from both sides of the cap beam, and there is no contact between the inserted vibrating rod and the airbag core mold.

9. The method for constructing a prefabricated cap beam airbag core mold according to claim 1, characterized in that: After the concrete is poured and cured to the target strength, the airbag core mold is deflated, and the airbag is removed from the poured cap beam by gently pulling it out.

10. The method for constructing a prefabricated cap beam airbag core mold according to claim 9, characterized in that: The surface of the disassembled airbag core mold needs to be cleaned, and a protective agent should be applied to the cleaned airbag surface.

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