A method for constructing secondary concrete of a fabricated door trough

Abstract

The application discloses a kind of assembly type door slot second phase concrete construction methods, it is related to construction technology field, method steps include: in first phase concrete, pre-buried connecting tendon assembly one, and connecting tendon assembly one is welded with the main reinforcement in first phase concrete;Prefabricated assembly type second phase concrete prefabricated component is prefabricated, and pre-buried assembly is arranged in second phase concrete prefabricated component, pre-buried assembly at least includes I-steel and connecting tendon assembly two;First phase concrete is connected with assembly type second phase concrete prefabricated component by pre-buried connecting tendon assembly one, connecting tendon assembly two;Install first group of sealing formwork and second group of sealing formwork, pour self-compacting concrete, after concrete strength reaches specified requirement, remove first group of sealing formwork and second group of sealing formwork and carry out maintenance.The door slot second phase concrete of the application adopts prefabricated type, avoids the cumbersome procedure such as site installation formwork and fixed embedded part, and prefabricated concrete quality is good, significantly reduces the possibility of quality defect.

Description

Technical Field

[0001] This invention relates to the field of construction technology, specifically to a method for the second-stage concrete construction of prefabricated door slots. Background Technology

[0002] In hydraulic gate engineering, when pouring concrete for the gate piers, a space is typically reserved for the second-stage concrete pouring at the corresponding location in the gate slot. After the first-stage concrete has set, the gate's embedded parts are installed, and then formwork is erected for the second-stage concrete pouring. Traditional gate embedded part installation and formwork erection are cumbersome, time-consuming, and labor-intensive. When using conventional cast-in-place methods for the second-stage concrete pouring, insufficient vibration often leads to surface defects such as honeycomb, pitting, and hollow areas. Even worse, if there is insufficient vibration or improper placement height, it can cause aggregate segregation and bleeding, resulting in a loose concrete structure, poor bonding, and ultimately, loosening and detachment of embedded parts, as well as water leakage in the gate slot, seriously affecting the construction quality of the gate slot. Summary of the Invention

[0003] This invention addresses the problems of construction quality defects and low construction efficiency in the secondary concrete of hydraulic gate slots in existing technologies, and provides a prefabricated method for secondary concrete construction of gate slots.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A method for second-stage concrete construction of prefabricated door slots includes the following steps:

[0006] Step S1: In the first-stage concrete, pre-embed the first connecting bar assembly, and weld the first connecting bar assembly to the main reinforcement in the first-stage concrete;

[0007] Step S2: Precast precast concrete components for the second phase of assembly, and install embedded components in the precast concrete components for the second phase of assembly. The embedded components include at least I-beams and connecting bar components.

[0008] Step S3: Connect the first-phase concrete with the prefabricated second-phase concrete components using pre-embedded connecting bar assembly one and connecting bar assembly two.

[0009] Step S4: Install the first set of sealing templates and the second set of sealing templates, pour self-compacting concrete, and after the concrete strength reaches the specified requirements, remove the first set of sealing templates and the second set of sealing templates and carry out curing.

[0010] Based on the above technical solution, further, in step S1, the connecting bar assembly includes at least a first connecting bar and a second connecting bar, wherein the first connecting bar is made of threaded steel bar, the second connecting bar is made of plain round steel bar, and there is at least a 20cm interval between two adjacent first connecting bars and at least a 40cm interval between two adjacent second connecting bars.

[0011] Based on the above technical solution, further, in step S3, the second connecting bar assembly includes at least a third connecting bar and a fourth connecting bar, wherein the third connecting bar is made of threaded steel bar, the fourth connecting bar is made of plain round steel bar, and there is at least a 20cm interval between two adjacent third connecting bars and at least a 40cm interval between two adjacent fourth connecting bars.

[0012] Based on the above technical solution, the first connecting bar and the third connecting bar are connected by extrusion sleeve. First, half of the sleeve is put on the first connecting bar, and then the prefabricated concrete component of the second phase of the assembly is hoisted to the corresponding position of the door slot, and the other half of the sleeve is put on the third connecting bar.

[0013] Based on the above technical solution, the second connecting bar and the fourth connecting bar are connected by lap splicing. The precast concrete components of the second phase of the assembly are hoisted to the corresponding positions of the door slot. The second connecting bar has a bending structure and the fourth connecting bar has a recess. The recess is lapped onto the bending position of the second connecting bar.

[0014] Based on the above technical solution, further, in step S4, the first set of sealing templates is installed below the sleeve, and the first set of sealing templates is set along the direction of water flow. A steel pipe is provided below the first set of sealing templates. One end of the steel pipe is connected to the first connecting rib by using iron wire, and the other end of the steel pipe is connected to the third connecting rib by using iron wire, thereby reinforcing the first set of sealing templates located between the steel pipe and the first and third connecting ribs.

[0015] Based on the above technical solution, further, in step S4, the construction process of pouring concrete is as follows: after the extrusion sleeve completes the extrusion, the first set of sealing templates and the second set of sealing templates are installed, and then concrete is poured; since the amount of concrete is small, a mixer is used on site to mix self-compacting concrete, and then manual labor is used in conjunction with scaffolding and chutes to pour the concrete into the corresponding compartment surface.

[0016] Based on the above technical solution, further, in step S4, the concrete strength is specified as follows: when the concrete strength is sufficient to ensure that the surface and edges of the second-phase concrete formwork are not damaged by the demolition operation, the demolition operation is carried out.

[0017] Based on the above technical solution, further, in step S4, the process of removing the formwork and curing is as follows: the second-phase concrete formwork is removed from top to bottom; after the second-phase concrete formwork is removed, the exposed iron wires on the concrete surface are cut with pliers, and cement mortar is applied to the cut to prevent rust; the concrete is cured by sprinkling water, and the curing time is not less than 28 days.

[0018] Based on the above technical solution, further, in step S4, at least two second-group sealing templates are set, and the two second-group sealing templates are installed between two adjacent H-beams. Each H-beam is equipped with one second-group sealing template, and both second-group sealing templates are set along the direction perpendicular to the water flow. Square timber and wooden wedges are provided between the two second-group sealing templates, wherein the distance between adjacent square timbers is no more than 20cm; because the square timbers serve as supports, their spacing should not be too large, otherwise the corresponding sealing templates are prone to deformation during the concrete pouring process.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The second-stage concrete of the gate slot of the present invention adopts a precast form, which avoids the cumbersome process of on-site installation of formwork and fixing of embedded parts, and the precast concrete has good quality, which significantly reduces the possibility of quality defects; the connecting bars are connected by sleeves and special structural forms, which is simple and quick to operate; the gap between the first-stage concrete and the second-stage concrete is filled with self-compacting concrete, which eliminates the need for vibration and other processes, saving time and effort. In contrast, the existing technology uses the cast-in-place method for the construction of the second-stage concrete of the gate slot, which generally does not have reinforcement, so the first-stage concrete and the second-stage concrete do not need to reserve the connecting bar components; the second-stage concrete of the gate slot is generally conventional concrete and does not use self-compacting concrete.

[0021] (2) The construction method of the present invention involves pre-embedding the first and second connecting bars in the first-stage concrete and welding them to the main reinforcement of the sluice gate pier; pre-embedding the corresponding connecting bar assembly 2 and I-beams in the precast concrete components of the second-stage prefabricated gate slot, with the connecting bar assembly 2 arranged vertically according to the spacing of the first-stage concrete connecting bar assembly 1, wherein the connecting bars are connected by extrusion sleeves or lap joints; the gap between the first-stage concrete and the second-stage concrete is filled with self-compacting concrete to protect the connecting bars, and at the same time make the first-stage concrete and the second-stage concrete form a whole, which plays a role in force transmission. Attached Figure Description

[0022] Figure 1 This is a flowchart of the construction method of the present invention;

[0023] Figure 2 This is a schematic diagram of the installation of pre-embedded components in the prefabricated components during the construction of this invention;

[0024] Figure 3 This is an assembly structure diagram of the second and fourth connecting bars in the construction structure of the present invention.

[0025] Figure 4 This is a structural diagram of the steel pipe installation in the construction structure of this invention;

[0026] Figure 5This is a schematic diagram of a certain state during the construction of the scaffolding and flow pipe in the construction structure of the present invention;

[0027] Reference numerals in the attached drawings: 1. First connecting rib; 2. Second connecting rib; 3. Third connecting rib; 4. Fourth connecting rib; 5. Sleeve; 6. First set of sealing templates; 7. I-beam; 8. Wire; 9. Steel pipe; 10. Second set of sealing templates; 11. Square timber; 12. Wooden wedge; 13. Chute; 14. Support; 15. Loading bucket; 16. Scaffolding; 17. Mixing bucket. Detailed Implementation

[0028] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly, provided that there is no mutual conflict.

[0029] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Technical features in the various embodiments of the present invention can be combined accordingly without mutual conflict.

[0030] In the description of this invention, it should be understood that when an element is considered to be "connected" to another element, it can be a direct connection to the other element or an indirect connection, i.e., there is an intermediate element. Conversely, when an element is said to be "directly" connected to another element, there is no intermediate element.

[0031] In the description of this invention, it should be understood that the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" and "second" may explicitly or implicitly include at least one of those features.

[0032] Example

[0033] The conventional method for constructing gate slots is to first pour the first-stage concrete for the gate pier. After the gate pier concrete has set, embedded parts are installed and formwork is installed, followed by the second-stage concrete pouring. Figures 1-4 As shown, this method implements a prefabricated door slot secondary concrete construction method, wherein, Figure 1 The shaded area containing the diagonal line represents the first-stage concrete, while the rest represents the second-stage concrete. Figure 2The structural diagram of the precast components differs from traditional schemes in that it uses conventional cast-in-place secondary concrete to prefabricate the components in a factory, creating secondary concrete precast components. These precast components embed multiple connecting bar assemblies and I-beam assemblies. After the secondary concrete precast components are installed on-site, a gap exists between them and the primary concrete of the gate pier. This gap needs to be filled and compacted with concrete, known as post-cast concrete, which serves to protect the connecting components.

[0034] The specific method includes the following steps:

[0035] Step S1: In the first-stage concrete, a first connecting bar assembly is pre-embedded, and the first connecting bar assembly is welded to the main reinforcement bars in the first-stage concrete; wherein the first connecting bar assembly includes at least a first connecting bar 1 and a second connecting bar 2, wherein the first connecting bar 1 is a threaded steel bar, and the second connecting bar 2 is a plain round steel bar, with a minimum interval of 20cm between two adjacent first connecting bars 1 and a minimum interval of 40cm between two adjacent second connecting bars 2 along the vertical direction. The interval between the first connecting bars 1 and the second connecting bars 2 can be set according to actual needs.

[0036] Step S2: Precast precast concrete components for the second phase of construction, and install embedded components in these components. These embedded components include at least I-beams (7) and connecting reinforcement components (2). Precasting the second phase of concrete requires material preparation and mold making. For example, since precast concrete materials include cement, sand, aggregates, and water, these materials need to be inspected and certified for quality before construction to ensure they meet relevant requirements. Furthermore, precast second-phase concrete requires mold making according to design requirements. Common mold materials include steel plates and plywood. The finished molds need to be inspected and treated for corrosion and erosion. Precast concrete mixing can be done at a batching plant or a suitable site. Traditionally, cement, sand, aggregates, and other materials are placed in a concrete mixer; the mixer is then started, and the mixing time needs to be adjusted according to specific requirements. The mixed concrete needs to be marked to ensure that the materials used can be traced at the construction site.

[0037] Step S3: Connect the first-phase concrete with the prefabricated second-phase concrete components using pre-embedded connecting bar assembly one and connecting bar assembly two. Connecting bar assembly two includes at least a third connecting bar 3 and a fourth connecting bar 4. The third connecting bar 3 is made of threaded steel bar, and the fourth connecting bar 4 is made of plain round steel bar. There is a minimum interval of 20cm between adjacent third connecting bars 3 and a minimum interval of 40cm between adjacent fourth connecting bars 4. The first connecting bar 1 and the third connecting bar 3 are connected by a compression sleeve 5. First, half the length of the sleeve 5 is fitted onto the first connecting bar 1. Then, the prefabricated second-phase concrete components are hoisted to the corresponding position in the doorway, and the other half of the sleeve 5 is fitted onto the third connecting bar 3. Figure 3 The second connecting bar 2 and the fourth connecting bar 4 are connected by an lap joint. The precast concrete components of the second phase are hoisted to the corresponding positions in the doorway. The second connecting bar 2 has a bent structure, and the fourth connecting bar 4 has a recessed portion, which is lapped onto the bent position of the second connecting bar 2. Specifically, the two ends of the second connecting bar 2 are located within the first-phase concrete, the bent portion of the second connecting bar 2 is located within the post-cast concrete, and the fourth connecting bar 4 is lapped onto the bent structure of the second connecting bar 2 located within the post-cast concrete.

[0038] Step S4: Install the first set of sealing templates 6 and the second set of sealing templates 10, pour self-compacting concrete, and after the concrete strength reaches the specified requirements, remove the first set of sealing templates 6 and the second set of sealing templates 10 and carry out curing.

[0039] Specifically, the first set of sealing templates 6 is installed below the sleeve 5, and the first set of sealing templates 6 is set along the direction of water flow. A steel pipe 9 is installed below the first set of sealing templates 6. One end of the steel pipe 9 is connected to the first connecting rib 1 using wire 8, and the other end of the steel pipe 9 is connected to the third connecting rib 3 using wire 8, thereby reinforcing the first set of sealing templates 6 located between the steel pipe 9 and the first and third connecting ribs 1 and 3. The concrete pouring process is as follows: after the extrusion sleeve 5 has completed extrusion, the first set of sealing templates 6 and the second set of sealing templates 10 are installed, and then concrete is poured. Due to the small amount of concrete, a mixer is used on-site to mix self-compacting concrete, and then manual labor, in conjunction with scaffolding 16 and chutes 13, pours the concrete into the corresponding compartment surface, combined with... Figure 5As shown, a material container 15 is placed on the scaffold 16, and a support 14 is installed on the scaffold 16. The support 14 is used to stabilize the chute 13. Specifically, after the second-phase precast concrete components are installed, the gap between them and the first-phase concrete needs to be filled with concrete to make it dense. On the construction site, given a fixed gate height, to avoid multiple formwork erections, it is recommended that the formwork for the post-cast concrete be erected at a height of not less than 2m at a time, and the pouring operation should be carried out using a liftable scaffold 16 construction platform. First, concrete is mixed using a concrete mixing bucket 17 and filled with material using the material container 15. Then, construction workers standing on the construction platform of the scaffold 16 use ropes to lift the material container 15 to the construction platform of the scaffold 16 and move it above the chute 13. The material is then unloaded through the chute 13 to complete the concrete pouring operation. The concrete strength requirement is ≥2.5MPa. Formwork removal can proceed when the concrete strength is sufficient to prevent damage to the surface and edges of the secondary concrete formwork during the removal process. The formwork removal and curing process is as follows: the secondary concrete formwork is removed from top to bottom; after removal, the exposed wire 8 on the concrete surface is cut with pliers, and the cut is coated with cement mortar to prevent rust; the concrete is cured by watering for at least 28 days. At least two second-group sealing templates 10 are provided, and the two second-group sealing templates 10 are installed between two adjacent H-beams 7. Each H-beam 7 is equipped with one second-group sealing template 10, and both second-group sealing templates 10 are set along the direction perpendicular to the water flow. A square timber 11 and a wooden wedge 12 are provided between the two second-group sealing templates 10. Specifically, one second-group sealing template 10 is set between one end of the square timber 11 and one H-beam 7, and the other end of the square timber 11 is connected to a wooden wedge 12 with an inclined angle. Another second-group sealing template 10 is set between the wooden wedge 12 and another H-beam 7 to enhance stability. The distance between adjacent square timbers 11 is not greater than 20cm. Because the square timbers 11 serve as supports, their spacing should not be too large, otherwise the corresponding sealing templates are prone to deformation during the concrete pouring process. Specifically, the concrete space in the second stage of the gate slot is narrow and not suitable for pouring tools such as chutes, guide pipes, or tremie pipes. To avoid segregation of concrete poured at high altitudes, the layer pouring height should not exceed 2m. Therefore, when the door groove height is greater than 2m, it should be poured in stages, and the height of each formwork erection should not exceed 2m.

[0040] The construction principle of this method is as follows:

[0041] In the first-stage concrete, the first connecting bar 1 and the second connecting bar 2 are pre-embedded and welded to the main reinforcement of the sluice gate pier. In the precast concrete components of the second-stage prefabricated gate slot, corresponding connecting bar assemblies 2 and I-beams 7 are pre-embedded. The connecting bar assemblies 2 are arranged vertically according to the spacing of the first-stage concrete connecting bar assemblies 1. The connecting bars are connected by extrusion sleeves 5 or by lap splicing. The gaps between the first-stage and second-stage concrete are filled with self-compacting concrete to protect the connecting bars and to form a unified whole, thus transferring force. By adopting a prefabricated method, the cumbersome procedures of on-site formwork installation and fixing of embedded parts are avoided. The precast concrete has high quality, significantly reducing the possibility of quality defects. The connecting bars are lapped using sleeves 5 and a special structural design, making the operation simple and quick. The filling of the gaps between the first-stage and second-stage concrete with self-compacting concrete eliminates the need for vibration, saving time and labor. In actual operation, the following should be noted: 1. The connecting bars using sleeve 5 should be threaded steel bars, and the connecting bars using lap joints should be plain round steel bars; 2. The precast secondary concrete is a slender structure, and its verticality should be strictly controlled to avoid bending.

[0042] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for second-stage concrete construction of prefabricated door slots, characterized in that, Includes the following steps: Step S1: In the first-stage concrete, pre-embed the first connecting bar assembly, and weld the first connecting bar assembly to the main reinforcement in the first-stage concrete; Step S2: Precast precast concrete components for the second phase of assembly, and install embedded components in the precast concrete components for the second phase of assembly. The embedded components include at least I-beams and connecting bar components. Step S3: Connect the first-phase concrete with the prefabricated second-phase concrete components using pre-embedded connecting bar assembly one and connecting bar assembly two. Step S4: Install the first set of sealing templates and the second set of sealing templates, pour self-compacting concrete, and after the concrete strength reaches the specified requirements, remove the first set of sealing templates and the second set of sealing templates and carry out curing. In step S1, the connecting rib assembly includes at least a first connecting rib and a second connecting rib; In step S3, the second connecting rib assembly includes at least a third connecting rib and a fourth connecting rib; The first connecting bar and the third connecting bar are connected by a compression sleeve. First, half of the sleeve is put on the first connecting bar, and then the prefabricated concrete component of the second phase of the prefabrication is hoisted to the corresponding position of the door slot, and the other half of the sleeve is put on the third connecting bar. The second connecting bar and the fourth connecting bar are connected by lap splicing. The precast concrete components of the second phase of the assembly are hoisted to the corresponding positions of the door slot. The second connecting bar has a bending structure and the fourth connecting bar has a recess. The recess is lapped onto the bending position of the second connecting bar. In step S4, the first set of sealing templates is installed below the sleeve, and the first set of sealing templates is set along the direction of water flow. A steel pipe is provided below the first set of sealing templates. One end of the steel pipe is connected to the first connecting rib by a wire, and the other end of the steel pipe is connected to the third connecting rib by another wire, thereby reinforcing the first set of sealing templates located between the steel pipe and the first and third connecting ribs. The second set of sealing templates shall be provided in at least two, and the two second sets of sealing templates shall be installed between two adjacent I-beams. Each I-beam shall be equipped with one second set of sealing template, and both second sets of sealing templates shall be set along the direction perpendicular to the water flow. Square timber and wooden wedges shall be provided between the two second sets of sealing templates, wherein the distance between adjacent square timbers shall not be greater than 20cm.

2. The prefabricated door slot secondary concrete construction method according to claim 1, characterized in that, The first connecting bar is made of threaded steel bar, and the second connecting bar is made of plain round steel bar. There is a minimum interval of 20cm between two adjacent first connecting bars and a minimum interval of 40cm between two adjacent second connecting bars.

3. The prefabricated door slot secondary concrete construction method according to claim 2, characterized in that, The third connecting bar is made of threaded steel bar, and the fourth connecting bar is made of plain round steel bar. There should be at least a 20cm interval between two adjacent third connecting bars and at least a 40cm interval between two adjacent fourth connecting bars.

4. The prefabricated door slot secondary concrete construction method according to claim 1, characterized in that, In step S4, the concrete pouring process is as follows: self-compacting concrete is mixed on site using a mixer, and then the concrete is poured into the formwork surface by manual labor in conjunction with scaffolding and chutes.

5. The prefabricated door slot secondary concrete construction method according to claim 1, characterized in that, In step S4, the concrete strength requirement is: when the concrete strength is ≥2.5MPa, and the surface and edges of the second-stage concrete formwork are not damaged by the removal operation, the formwork removal operation shall be carried out.

6. The prefabricated door slot secondary concrete construction method according to claim 5, characterized in that, In step S4, the formwork removal and curing process is as follows: the second-phase concrete formwork is removed from top to bottom; after the second-phase concrete formwork is removed, the exposed wires on the concrete surface are cut with pliers, and cement mortar is applied to the cut surfaces; the concrete is cured by sprinkling water, and the curing time is no less than 28 days.

Images