Underground engineering floor post-cast strip formwork and system

Abstract

The present application discloses a template and system for a post-cast strip of a basement floor slab, including: a reinforcing bar holding strip formwork unit with a height of 50 mm, and a foam soft pad is further arranged on the groove-shaped inner side of the reinforcing bar holding strip formwork unit. When the reserved reinforcing bar passes through the reinforcing bar holding hole, the foam soft pad closely adheres to the reserved reinforcing bar, so that a small amount of cement slurry passing through the narrow gap between the reserved reinforcing bar and the reserved reinforcing bar hole is immediately blocked and no longer diffuses after passing through the reinforcing bar holding hole; a basic formwork unit, having the same length as the reinforcing bar holding strip formwork unit, and at least including two height specifications of 200 mm and 300 mm; a selected number of reinforcing bar holding strip formwork units and a selected number or height specification of basic formwork units form post-cast strip formworks with different thicknesses to adapt to the pouring works of the post-cast strips of the floor slabs with corresponding thicknesses, thereby realizing the standardization and large-scale production of the post-cast strip formworks, effectively improving the overall pouring quality of the post-cast strip concrete, and thus changing the current situation of "always leaking" of the post-cast strip.

Description

Technical Field

[0001] The present application relates to the technology of post-cast strips in underground engineering, and particularly to a formwork and system for the post-cast strip of the floor slab in underground engineering. Background Art

[0002] For post-cast strips in underground engineering, the wooden formwork technology was adopted decades ago. Due to the shortage of domestic timber and small material consumption at that time, the turnover rate was very low, and it has never been developed as it should be. Decades later, due to the introduction of the quick-installing closure net, the traditional technology was completely abandoned.

[0003] The closure net is originally a non-removable net - but only the net itself does not need to be removed, while the supporting reinforcing bars and edge sealing strips should be removed completely before the post-cast concrete. The edge sealing strips and reinforcing bars are complex in structure and need to be designed by a qualified formwork engineer. After the closure net was domesticated, the concept of another type of closure net made of thick stainless steel plate was applied (this net is firm, with single material consumption, and can be constructed with high precision, and there is nothing to be removed): the edge sealing strips and reinforcing bars were cancelled, and the net plate was thinned and the structure was weakened, resulting in serious leakage. So the non-removable net became a must-remove net: as long as it is not removed completely, water leakage will surely occur. Moreover, due to the unreasonable simplification of other related designs at the same time, there is no operating space for removing the net, and the removal of the net was completely abandoned. The result is that for post-cast strips, without removing the net, there will always be leakage. For the operating projects, most rely on diversion drainage and repeated grouting to stop leaks, which is difficult to cure completely, resulting in the projects having problems at a young age and having to continue with problems. Therefore, it is more reliable to return to the traditional wooden formwork technology. Only when it is reliable can we talk about being fast and economical.

[0004] The special feature of the traditional technology lies in the formwork for passing through the reserved bars of the post-cast strip: generally, each of the upper and lower wooden beams has a semi-circular groove to hold the protruding reserved bars, so that less slurry overflows during the pouring of concrete, the interface cleaning is relatively easy, the quality of the critical concrete is guaranteed, and the waterproof effect is better than that of the closure net. The disadvantage is that it is customized on-site for each project, with one-time formwork support, which is labor-consuming and material-consuming and not environmentally friendly.

[0005] As the scale of the project is getting larger and larger, large-scale setting of post-cast strips instead of deformation joints has become the mainstream technology, and the on-site workload is large, making the one-time formwork even more unreasonable. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present application is to provide a formwork and system for the post-cast strip of the floor slab in underground engineering to solve the problems in the prior art that the post-cast strip formwork needs to be customized on-site, with one-time formwork support, which is labor-consuming, material-consuming and not environmentally friendly.

[0007] The technical solutions adopted by the present application to solve the above technical problems are as follows:

[0008] One aspect of the present application provides a formwork for the post-cast strip of the floor slab in underground engineering, including:

[0009] The stirrup bar formwork unit, with a height of 50 mm, includes a first stirrup bar and a second stirrup bar. A composite splint is arranged between the first stirrup bar and the second stirrup bar to form a groove shape; several semi-stirrup holes are arranged at the edge of each stirrup bar.

[0010] A foam soft pad is also arranged on the inner side of the groove shape of the stirrup bar formwork unit. When the reserved bar passes through the stirrup hole, the foam soft pad closely adheres to the reserved bar, so that a small amount of cement slurry passing through the narrow gap between the reserved bar and the reserved bar hole is immediately blocked and no longer spreads after passing through the stirrup hole.

[0011] The basic formwork unit is the same length as the stirrup bar formwork unit and includes at least two height specifications of 200 mm and 300 mm.

[0012] A selected number of stirrup bar formwork units and a selected number or height specification of basic formwork units form post-cast strip formworks with different thicknesses to adapt to the pouring projects of the post-cast strips of the floor slabs with corresponding thicknesses.

[0013] Among them, the basic formwork unit is composed of an 18-mm-thick eleven-layer splint and a 50 mm × 100 mm wooden square, with a length of 600 mm or 900 mm; the splints and the wooden squares are assembled, and both use water-resistant glue and countersunk wood screws, combining gluing and nailing.

[0014] Among them, the stirrup bar formwork unit has a width of 118 mm, a height of 50 mm, and a length of 600 or 900, with openings at both ends. The first stirrup bar and the second stirrup bar are 18-mm-thick eleven-layer splints, and the width of the composite splint is 82 mm.

[0015] Among them, the composite splint is composed of an 18-mm-thick eleven-layer splint and a 15-mm-thick nine-layer splint. Between the splints, both use water-resistant glue and countersunk wood screws, combining gluing and nailing.

[0016] Among them, the semi-aperture diameter of the stirrup bar is Φ30, and the outer edge of the hole has a 45°, 2.0-wide chamfer.

[0017] Among them, a post-cast strip formwork including at least 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, and 1000 mm is formed by 4 of the above-mentioned stirrup bar formwork units and a selected number or height specification of basic formwork units.

[0018] Another aspect of the present application provides a post-cast strip formwork system for the basement engineering floor slab, including:

[0019] Any one of the above post-cast strip formworks;

[0020] Supports, used to form a supporting force outside the formwork.

[0021] Among them, the supports include horizontal braces and vertical braces. The braces are made of thick galvanized steel square tubes. The spacing of the vertical braces is 600 mm or 900 mm, and the vertical braces are close to the reserved bars at the upper and lower ends of the formwork. The horizontal braces, with the same spacing as the vertical braces, are arranged in the ballast trough.

[0022] Among them, a gap of about 50 mm to 70 mm is reserved between the horizontal braces and the vertical braces, and is wedged tightly by a pair of hardwood wedges.

[0023] Among them, temporary horizontal bars are arranged on the outside of the reserved bars passing through the hoop bar formwork unit, and the temporary horizontal bars are spot-welded to the reserved bars.

[0024] The post-cast strip formwork and system for the basement floor in the embodiment of the present application form formworks suitable for different thicknesses by modularly designing the hoop bar formwork units and the basic formwork units, and the assembly can be carried out on-site or completed in the factory; after the formwork is removed, it can also be disassembled again into the hoop bar formwork units and the basic formwork units for later use. It can be seen that the formwork of the present application not only has strong adaptability to basement floors of different thicknesses, but can also be reused, reducing costs and being environmentally friendly, and completely solving the overall pouring quality of the post-cast strip concrete, thus changing the current situation of "always leaking" in the post-cast strip. Description of the Drawings

[0025] Figure 1 It is a cross-sectional view of the hoop bar formwork unit of the post-cast strip formwork provided by the embodiment of the present application;

[0026] Figure 2 For Figure 1 The front view of the hoop bar formwork unit shown;

[0027] Figure 3 For Figure 1 The top view of the hoop bar formwork unit shown;

[0028] Figure 4 It is the front view of the basic formwork unit of the post-cast strip formwork provided by the embodiment of the present application;

[0029] Figure 5 It is the structural schematic diagram of the post-cast strip formwork of an embodiment of the present application;

[0030] Figure 6 It is the structural schematic diagram of the post-cast strip formwork system of an embodiment of the present application. Detailed Embodiments

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer and more understandable, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] In this application, all length units are in mm.

[0033] To solve the problems brought by the once-through post-cast strip formwork, this application needs to consider a formwork that can be reused and has strong adaptability. The difficulty lies in the fact that the thickness of the floor slab varies, the spacing of the reserved reinforcement bars varies, and the diameter of the reinforcement bars varies, making it difficult to solve the standardization and modularization of the formwork. This application intends to resolve the above difficulties through systematic prefabrication, assembly, and bar-holding structure of the formwork.

[0034] As Figure 1 shown, the bar-holding strip formwork unit includes two parallel bar-holding strips 10 as shown in Figure 1 . A composite clamping plate 20 is arranged between the two bar-holding strips 10. The composite clamping plate is composed of an 18-mm-thick eleven-layer clamping plate and a 15-mm-thick nine-layer clamping plate. The width of the composite clamping plate is 82 mm. When the clamping plates are assembled with each other and with the wooden beams, waterproof glue and countersunk wood screws are used simultaneously for bonding and nailing. The bar-holding strip 10 and the composite clamping plate 20 form a groove-shaped bar-holding strip formwork unit A. A foam soft pad 30 is arranged on the inner side of the groove shape. When the reserved reinforcement bar passes through the bar-holding hole, the foam soft pad 30 can closely adhere to the reserved reinforcement bar, so that a small amount of cement slurry passing through the narrow gap between the reserved reinforcement bar and the reserved reinforcement hole is immediately blocked and no longer diffuses after passing through the bar-holding hole. Since the bar-holding strip 10 is 50 mm high and 18 mm thick, and the width of the composite clamping plate is 82 mm, the composed bar-holding strip formwork unit A is 50 mm high, 118 mm wide, and 600 mm or 900 mm long, with both ends open.

[0035] The material of the foam soft pad 30 is PVC / NBR. The foam is closed-cell, with a surface skin not less than 0.5 mm thick, and the skin is formed by cooling with ice water after foaming. The soft pad is cut into a thickness of 17 mm, a width of 82 mm, and a length of 600 mm or 900 mm with a special electric saw blade. The density of the soft pad is adjusted by the formula. The formula is determined through experiments so that when the linear compression at the reinforcement bar passing-through part is only 3.0 thick at the most, it still maintains toughness. The soft pad is adhered to the groove with a special waterproof epoxy adhesive, and the bonding surface is limited to the bottom surface of the soft pad, and the side surface is not adhered.

[0036] As Figure 2 and Figure 3 shown, a number of bar-holding semi-holes 11 are arranged at the edge of each bar-holding strip 10, and the distances between the bar-holding semi-holes are equal; the aperture of the bar-holding hole is Φ30, and the outer edge of the hole has a 45°, 2.0-wide chamfer. The bar-holding holes on both sides of the bar-holding strip are divided into three series according to the spacing of the reserved reinforcement bars, including @150, @200, and @250. The range that can adapt to the reserved reinforcement bars includes and which can meet the needs of the vast majority of projects. At the clamping plate cross-section of all the bar-holding semi-holes of the bar-holding strips, a waterproof glue for enhancement is applied before assembly. This glue is preferably 495 instant-drying glue.

[0037] like Figure 4 The basic formwork unit B shown is of the same length as the reinforcing bar formwork unit A and has at least two height specifications of 200 mm and 300 mm in height; the basic formwork unit B is composed of 11 layers of 18 mm thick plywood 50 and 50 mm high × 100 mm wide wooden beams 40.

[0038] A selected number of reinforcing bar formwork units A and a selected number or height specification of basic formwork units B can form post-casting strip formworks of different thicknesses to adapt to the pouring project of the post-casting strip of the base plate of corresponding thickness.

[0039] like Figure 5 The figure shows a combination of two bar mould units A and basic formwork unit B, with the reserved bar 60 passing through the bar holes of bar mould unit A. In practice, the thickness of thin base plates is mostly 400, the thinnest is 350, and most of them are formed with different thicknesses in increments of 100 moduli. For individual base plates with a thickness of 50, the base plate can be thickened by 50 at a range of about 300 on both sides of the post-casting strip, so that the plate thickness modulus in the strip is adjusted back to 100 modulus, so as to facilitate the adaptation to standardized formwork. Since the bar mould unit is 50 high, and the basic formwork unit B has two height specifications of 200mm and 300mm high, the combination of the three can adapt to all plate thicknesses with base plate thickness of 400 and above and incremented by 100 moduli. Templates of different thicknesses can be assembled in the factory, using Φ8 bolts, two in each plate, and only three types of templates can adapt to base plates with thicknesses of 400, 500, 600, 700, 800, 900, 1000, ... Over 1000, they can be pre-assembled into large blocks in the factory to reduce on-site workload. The combination methods are listed below:

[0040]

[0041] like Figure 6The post-cast strip formwork system for the basement floor shown is provided with formwork at the post-cast strip 200 for pouring the floor slab 100. The combination method of the formwork is determined by the thickness of the floor slab 100. The formwork is composed of multiple hoop bar formwork units A and basic formwork units B. The reserved bars 60 pass through the hoop holes of the hoop bar formwork units A. Vertical supports C and horizontal supports D are arranged on the other side of the formwork. The horizontal supports D are arranged in the sediment trough with a depth of 100 mm and a width of about 600 mm, so that the net width for post-cast strip operation remains between 1000 mm and 1200 mm for both thick and thin floor slabs. The support frame is made of thick galvanized steel square tubes, □50×50×4, prefabricated in the factory, fully welded, sealed, with the weld slag removed and rust-proofed. The spacing of the vertical supports C is 600 mm or 900 mm. The support frame can be closely attached to the reserved bars at the upper and lower ends of the formwork, and the two are tied for stability. Temporary cross bars 70 can be set on the upper reserved bars 60 and spot welded to the reserved bars 60. The temporary cross bars do not need to be removed. When the vertical support C is removed, it only needs to be slightly rotated to be withdrawn. When pouring the protective layer on the upper surface of the floor slab, the cross bars will be immersed in the concrete protective layer. The spacing of the horizontal supports is the same as that of the vertical supports, and its longitudinal stability can be solved by the diagonal braces arranged in the sediment trough. The diagonal braces can be fixed-type metal tie rods that can be tightened; they can also be directly nailed with temporary wooden beams. A gap of about 50 mm to 70 mm is reserved between the horizontal and vertical supports and is wedged tightly by pairs of hardwood wedges 90. The wooden wedges can be placed vertically or horizontally.

[0042] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, which does not limit the scope of the rights of the present application. Those skilled in the art can implement the present application in various variant schemes without departing from the scope and essence of the present application. For example, the features of one embodiment can be used in another embodiment to obtain another embodiment. Any modifications, equivalent replacements, and improvements made within the technical concept of the present application shall be within the scope of the rights of the present application.

Claims

1. A template for the post-cast strip of the basement floor of an underground project, characterized in that Comprising: The stirrup bar mold unit includes a first stirrup bar and a second stirrup bar. A composite splint is arranged between the first stirrup bar and the second stirrup bar to form a groove shape. A number of semi-stirrup holes are arranged at the edges of each stirrup bar. The width of the stirrup bar mold unit is 118 mm, the height is 50 mm, and the length is 600 mm or 900 mm. Both ends are open. The first stirrup bar and the second stirrup bar are eleven-layer splints with a thickness of 18 mm, and the width of the composite splint is 82 mm. A foam soft pad is also arranged on the inner side of the groove shape of the stirrup bar mold unit. When the reserved bar passes through the stirrup hole, the foam soft pad closely adheres to the reserved bar, so that a small amount of cement slurry passing through the narrow gap between the reserved bar and the stirrup hole is immediately blocked and no longer spreads after passing through the stirrup hole. The basic template unit is of the same length as the stirrup bar mold unit and includes at least two height specifications of 200 mm and 300 mm. The basic template unit is composed of an eleven-layer splint with a thickness of 18 mm and a 50 mm×100 mm wooden square. The length is 600 mm or 900 mm. The splints and the wooden squares are assembled by using waterproof glue and countersunk wood screws, with both gluing and nailing. A selected number of stirrup bar mold units and a selected number or height specification of basic template units form post-cast strip templates with different thicknesses to adapt to the pouring project of the post-cast strip of the floor slab with corresponding thicknesses.

2. The post-cast strip formwork for the basement floor of an underground project according to claim 1, wherein: The composite splint is composed of an eleven-layer splint with a thickness of 18 mm and a nine-layer splint with a thickness of 15 mm. Between the splints, waterproof glue and countersunk wood screws are used, with both gluing and nailing.

3. The post-cast strip formwork for the basement floor of an underground project according to claim 1, wherein: The aperture of the semi-stirrup hole is Φ30, and the outer edge of the hole has a 45°, 2.0 wide chamfer.

4. The post-cast strip formwork for the basement floor of an underground project according to claim 1, wherein: The post-cast strip template composed of 4 of the stirrup bar mold units and a selected number or height specification of basic template units includes at least 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, 1000 mm.

5. An underground engineering floor post-cast strip formwork system, characterized in that, Comprising: The post-cast strip template according to any one of claims 1-4; Supports for forming a supporting force outside the template.

6. The post-cast strip formwork system for the basement floor of underground engineering according to claim 5, wherein: The supports include transverse braces and vertical braces. The braces are made of thick galvanized steel square tubes. The spacing of the vertical braces is 600 mm or 900 mm. The vertical braces are close to the reserved bars at the upper and lower ends of the template. Transverse braces with the same spacing as the vertical braces are arranged in the slag trough.

7. The post-cast strip formwork system for the basement floor of an underground project according to claim 6, characterized in that: A space of 50 mm to 70 mm is reserved between the transverse braces and the vertical braces and is wedged tightly by a pair of hardwood wedges.

8. The post-cast strip formwork system for the basement floor of underground engineering according to claim 5, wherein: Temporary transverse bars are arranged on the outer side of the reserved bars passing through the stirrup bar mold unit, and the temporary transverse bars are spot-welded to the reserved bars.

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