Construction method of post-cast strip of precast floor top slab in super-long building

Abstract

The present invention discloses a method for constructing a post-cast strip of a precast floor top plate of an extra-long building, which belongs to the technical field of civil construction formwork. The method solves the problem of how to conveniently and reliably seal both sides of the post-cast strip and improve the quality of the combination of the secondary cast post-cast strip and the single-cast floor slab concrete; an inflatable and deflable flat rubber air bag is used to replace the sealing wood glue board strip under the steel mesh in the plate, thereby realizing the sealing of the concrete on both sides of the post-cast strip; when the concrete on both sides of the post-cast strip is finally set, the flat rubber air bag is deflated to shrink and is easy to remove, thereby ensuring the reliable combination of the subsequent post-cast strip concrete and the single-cast concrete, and convenient on-site operation; the present invention kills three birds with one stone, namely, it realizes the sealing of narrow gaps, and also facilitates the overall removal of the later sealing objects. In addition, the flat air bag is also reusable.

Description

Technical Field

[0001] The present invention relates to a post-cast strip of a precast floor top slab of an ultra-long building, and in particular to a blocking template structure on both sides of the post-cast strip of a precast floor top slab of an ultra-long building, and a construction method of the post-cast strip of a precast floor top slab of an ultra-long building. Background Art

[0002] In the cast-in-place concrete construction of the floor top slabs of buildings with longer spans, it is necessary to set up post-cast joints on the floor top slabs, first cast the floor top slab concrete on both sides of the post-cast joints, and after the expansion and settlement of the concrete floor top slabs cast on both sides of the post-cast joints are stable, the secondary concrete pouring of the floor top slabs at the post-cast joints can be carried out; when pouring the floor top slab concrete on both sides of the post-cast joints, it is necessary to isolate the post-cast joint area to prevent the concrete poured on both sides of the post-cast joints from flowing into the post-cast joint area, so that the post-cast joints can fully play the role of absorbing the prestress of the concrete floor slabs on both sides; according to the existing construction specifications, the steel mesh in the floor top slab is an integrated construction. That is to say, the steel mesh on the post-cast zone and the steel mesh on both sides of it are integrated and completed at the same time. These steel meshes are supported on the top surface of the floor top slab casting formwork through concrete horse stool pads to ensure that after the floor top slab is cast, a protective layer of steel mesh can be formed in the plate. The thickness of the steel protective layer at the bottom of the plate is generally between 2.5-3 cm. The on-site casting construction process of the floor top slab is as follows: after the steel mesh on the floor top slab is tied, the position of the post-cast zone is determined, and then, the blocking formwork is constructed on both sides of the post-cast zone. The blocking formwork includes dense steel wire mesh, wood glue board strips and cut concrete wooden slats. First, on both sides of the post-cast zone, the blocking formwork is constructed. A dense mesh steel wire mesh is set between the upper and lower steel meshes on the side to seal the cast-in-place concrete. Since the lower end of the dense mesh steel wire mesh cannot be inserted under the lower steel mesh, the gap between the lower steel mesh and the floor top slab casting template is sealed. On site, the gap just below the dense mesh steel wire mesh is generally sealed with wooden strips, and wooden slats for cutting off concrete are set on the upper steel mesh just above the dense mesh steel wire mesh, thereby completing the construction of a template system that completely blocks the cast-in-place concrete on one side of the post-casting strip; when the floor top slabs on both sides of the post-casting strip have completed expansion and contraction settlement, the floor top slab concrete casting template is removed. At this time, the sealing wooden strips have been separated from the cast-in-place concrete on both sides of the post-casting strip. The concrete of the post-casting zone is tightly combined together. Since the wood glue strips are easy to rot, according to relevant specifications, when pouring the post-casting zone concrete for the second time, the sealing wood glue strips must be taken out from the concrete that has been poured and finally set once. Then, the concrete pouring formwork of the post-casting zone is erected, and the secondary concrete pouring of the post-casting zone is carried out. Only in this way can the tight combination of the two pouring concretes be guaranteed. In actual operation, the removal of the sealing wood glue strips is time-consuming and labor-intensive, and the phenomenon of incomplete removal of the sealing wood glue strips often occurs, which seriously affects the bonding quality between the post-casting zone concrete and the poured floor top slab concrete. How to solve this problem is a difficulty that urgently needs to be solved in on-site construction. Summary of the Invention

[0003] The present invention provides a method for constructing a post-cast strip of a precast floor top slab of an extra-long building, which solves the technical problem in the prior art that the caulking wood strips in the sealing formwork on both sides of the post-cast strip of the floor top slab are difficult to remove later and become a hidden danger in the connection of the two pourings of concrete.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] The overall concept of the present invention is as follows: an inflatable and deflable flat rubber air bag is used to replace the sealing wooden strips under the lower steel mesh in the board to achieve the sealing of the concrete on both sides of the post-casting strip; when the concrete on both sides of the post-casting strip is finally set, the flat rubber air bag is deflated to shrink, and the air bag can be conveniently removed from the concrete as a whole, thereby creating good bonding conditions for the secondary pouring of the post-casting strip concrete, and the entire operation also has the advantages of saving time and labor; in addition, the flat rubber air bag is designed as a split unit air bag, and by connecting the end to end of multiple split unit air bags, and arranging these air bags connected end to end along the gap direction into an S shape, a tooth-shaped concrete bonding surface is constructed on both sides of the post-casting strip, thereby creating better conditions for the reliable bonding of the subsequent post-casting strip concrete with the primary pouring concrete.

[0006] A blocking formwork structure for both sides of the precast floor top slab post-casting strip of an ultra-long building comprises a floor top slab casting bottom formwork support, a floor top slab casting bottom formwork is arranged on the floor top slab casting bottom formwork support, concrete pads are arranged at intervals on the floor top slab casting bottom formwork, a lower layer of steel mesh in the slab is arranged on the concrete pads, and an upper layer of steel mesh in the slab is arranged above the lower layer of steel mesh in the slab; a floor top slab post-casting strip area is arranged on the floor top slab casting bottom formwork, a left-side dense steel wire mesh is arranged between the lower layer of steel mesh in the slab and the upper layer of steel mesh in the slab on the left side of the floor top slab post-casting strip area, and a gap is formed between the lower layer of steel mesh in the slab and the floor top slab casting bottom formwork. A left-side flat air bag is provided in the left-side gap formed between the plates. The left-side flat air bag is provided directly below the left-side dense steel wire mesh. A left-side wooden slat for cutting off the concrete is provided on the upper steel mesh in the plate directly above the left-side dense steel wire mesh. A right-side dense steel wire mesh is provided between the lower steel mesh in the plate and the upper steel mesh in the plate on the right side of the post-cast zone area of the floor top plate. A right-side flat air bag is provided in the right-side gap formed between the lower steel mesh in the plate and the bottom formwork for casting the floor top plate. The right-side flat air bag is provided directly below the right-side dense steel wire mesh. A right-side wooden slat for cutting off the concrete is provided on the upper steel mesh in the plate directly above the right-side dense steel wire mesh.

[0007] On the floor top slab casting bottom formwork on the left side of the floor top slab post-casting joint area, the floor slab concrete on the left side of the post-casting joint is cast, and on the floor top slab casting bottom formwork on the right side of the floor top slab post-casting joint area, the floor slab concrete on the right side of the post-casting joint is cast.

[0008] On the right side facade of the left flat airbag, there are respectively provided with an inflation and deflation nozzle and an airbag pulling handle, and an air nozzle plug is provided in the inflation and deflation nozzle; on the top surface of the left flat airbag, there is a groove for fixing the steel bar; the structure of the right flat airbag is exactly the same as that of the left flat airbag.

[0009] In the left gap formed between the lower steel mesh in the slab and the bottom formwork for casting the floor top slab, multiple left-side flat air bags are arranged end to end along the direction of the left gap. These left-side flat air bags are arranged in a serpentine shape to seal the left gap under the left dense-mesh steel mesh.

[0010] A method for constructing a post-cast strip of a precast floor top slab of an ultra-long building comprises: supporting a floor top slab casting bottom formwork support on a completed floor bottom slab below the precast floor top slab; setting up a floor top slab casting bottom formwork on the floor top slab casting bottom formwork support; setting up concrete pads at intervals on the floor top slab casting bottom formwork; supporting a lower layer of steel mesh in the slab on the concrete pads; and supporting an upper layer of steel mesh in the slab above the lower layer of steel mesh in the slab; and providing a floor top slab post-cast strip area on the floor top slab casting bottom formwork, characterized by the following steps:

[0011] The first step is to make a flat airbag, and to set an inflation and deflation nozzle and an airbag pulling handle on the side elevation of the flat airbag;

[0012] Step 2: Hang the dense steel mesh on the left side between the lower steel mesh and the upper steel mesh in the slab on the left side of the post-cast zone of the floor top slab;

[0013] Step 3: After inflating the flat airbag, place it in the left gap formed between the lower steel mesh in the slab and the bottom template of the floor top slab, so that the flat airbag is placed directly below the dense steel mesh on the left, and the inflation and deflation nozzles and the airbag pulling handle on the flat airbag are placed in the direction of the post-cast zone area of the floor top slab; multiple inflated flat airbags are connected end to end to block the left gap;

[0014] Step 4: Install the wooden slats on the left side of the concrete cut-off on the upper steel mesh in the slab just above the dense steel mesh on the left side;

[0015] Step 5: Follow the steps from Step 2 to Step 4 to install the dense steel wire mesh, flat airbags, and wooden slats on the right side of the concrete strip on the right side of the floor top slab post-casting zone; thus completing the layout of the blocking formwork on both sides of the floor top slab post-casting zone;

[0016] Step 6: Pour the floor slab concrete on the left side of the post-casting strip and the floor slab concrete on the right side of the post-casting strip;

[0017] Step 7: After the concrete of the floor slab on the left side of the post-casting zone and the concrete of the floor slab on the right side of the post-casting zone have finally set, remove the bottom formwork for pouring the top slab of the floor;

[0018] Step 8. Pull out the air nozzle plug on the flat airbag to deflate the flat airbag and then shrink it. Then, pull the handle through the airbag to take out the shrunken flat airbag.

[0019] Step 9: Set up the casting formwork for the post-casting zone of the floor top slab, and carry out secondary concrete pouring in the post-casting zone of the floor top slab.

[0020] The multiple inflated flat air bags used to seal the left side gap between the lower steel mesh in the slab and the bottom formwork for casting the floor top slab are arranged in an S-shaped end-to-end connection along the left side gap direction; the multiple inflated flat air bags used to seal the right side gap between the lower steel mesh in the slab and the bottom formwork for casting the floor top slab are arranged in an S-shaped end-to-end connection along the right side gap direction; thereby forming a tooth-shaped interface of concrete at the gaps on both sides of the post-cast zone area of the floor top slab, thereby improving the bonding quality of the secondary cast concrete in the post-cast zone area of the floor top slab and the once cast floor slab concrete.

[0021] The present invention arranges an inflatable flat airbag in the gap below the dense mesh steel wire mesh that blocks the two sides of the post-cast strip. By inflating the flat airbag, the concrete outside the gap is blocked, and then by deflating the flat airbag, the blocking airbag is completely removed from the narrow gap. The airbag can be tightly combined with the dense mesh steel wire mesh above, so as to achieve efficient blocking of the concrete on both sides of the post-cast strip and reduce the overflow of concrete caused by the gap. After the concrete on both sides of the post-cast strip is poured, the flat airbag is deflated and removed as a whole through the integrated pulling handle. The blocking template structure and the operation method thereof kill three birds with one stone, namely, blocking the narrow gap and facilitating the overall removal at a later time. In addition, the flat airbag is also reusable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention;

[0023] Figure 2 Schematic diagram of the arrangement structure of the flat airbags in the sealing gap of the present invention;

[0024] Figure 3 Schematic diagram of the structure of the left flat airbag 7 of the present invention;

[0025] Figure 4 1 is a schematic structural diagram of the steel bar fixing groove 14 on the left flat airbag 7 after inflation of the present invention. DETAILED DESCRIPTION

[0026] The present invention is described in detail below with reference to the accompanying drawings:

[0027] A blocking formwork structure for both sides of the post-casting strip of the precast floor top slab of an ultra-long building. The cast-in-place floor is generally cast in layers. When the precast floor top slab is constructed, the floor bottom slab below it has been cast and finally set. A floor top slab casting bottom formwork support 1 is set on the finally set floor bottom slab. A floor top slab casting bottom formwork 2 is set on the floor top slab casting bottom formwork support 1. Concrete pads are set at intervals on the floor top slab casting bottom formwork 2. A lower layer of steel mesh 3 in the slab is set on the concrete pads. Above the inner lower steel mesh 3, there is an inner upper steel mesh 9. After the above work is completed, the post-casting zone is constructed; on the floor top slab casting bottom formwork 2, there is a floor top slab post-casting zone 4. Between the inner lower steel mesh 3 and the inner upper steel mesh 9 on the left side of the floor top slab post-casting zone 4, there is a left dense steel wire mesh 8. In the left gap formed between the inner lower steel mesh 3 and the floor top slab casting bottom formwork 2, there is a left flat airbag 7. The left flat airbag 7 is set just below the left dense mesh steel wire mesh 8, and on the upper steel mesh 9 in the plate just above the left dense mesh steel wire mesh 8, a left wooden slat 10 for cutting off the concrete is set; between the lower steel mesh 3 in the plate on the right side of the post-cast zone area 4 of the floor top plate and the upper steel mesh 9 in the plate, a right dense mesh steel wire mesh is set, and in the right gap formed between the lower steel mesh 3 in the plate and the bottom template 2 of the floor top plate, a right flat air bag is set. The right flat air bag is set just below the right dense mesh steel wire mesh, and on the right On the upper steel mesh 9 in the plate just above the dense mesh steel wire mesh, there is a wooden slat on the right side of the cut concrete; with the inflated flat airbag, dense mesh steel wire mesh and the cut concrete wooden slat, a blocking template for the cast-in-place concrete on both sides of the post-cast strip is constructed. In particular, the inflated flat airbag solves the problem of blocking concrete in narrow gaps, and after completing its mission, it reduces its volume by deflating, creatively solving the problem of convenient and overall removal of the gap blocking material in the later stage, creating favorable conditions for the close bonding of the two concretes.

[0028] On the floor top slab casting bottom formwork 2 on the left side of the floor top slab post-casting strip area 4, the floor slab concrete 5 on the left side of the post-casting strip is cast, and on the floor top slab casting bottom formwork 2 on the right side of the floor top slab post-casting strip area 4, the floor slab concrete 6 on the right side of the post-casting strip is cast; the above is a one-time pouring of concrete to form the floor slabs on both sides of the post-casting strip. Due to the extra-long floor slab, the floor slabs on both sides can be expanded and contracted through the post-casting strip to fully release the stress.

[0029] On the right side facade of the left flat airbag 7, an inflation and deflation nozzle 11 and an airbag pulling handle 13 are respectively provided. A nozzle plug 12 is provided in the inflation and deflation nozzle 11. The inflation and deflation nozzle 11 is set toward the post-casting zone area to facilitate the later deflation and the overall removal of the flat airbag; on the top surface of the left flat airbag 7, fixed steel bar grooves 14 are provided, so that the steel bars at the bottom end of the dense steel wire mesh above are embedded in these grooves, so that the two are tightly combined to prevent overflow of concrete at the joints; the structure of the right flat airbag is exactly the same as that of the left flat airbag 7.

[0030] In the left gap formed between the lower steel mesh 3 in the slab and the bottom formwork 2 for casting the floor top slab, multiple left flat air bags 7 are arranged end to end along the direction of the left gap. These left flat air bags 7 are arranged in a serpentine shape to achieve the sealing of the left gap below the left dense-mesh steel wire mesh 8; multiple left flat air bags 7 are arranged in a serpentine shape, that is, connected in an S shape, which provides a more reliable sealing of the gap.

[0031] A method for constructing a post-cast strip of a precast floor top slab of an extra-long building comprises: supporting a floor top slab casting bottom formwork support 1 on a completed floor bottom slab below the precast floor top slab; setting up a floor top slab casting bottom formwork 2 on the floor top slab casting bottom formwork support 1; setting up concrete pads at intervals on the floor top slab casting bottom formwork 2; supporting a lower-layer steel mesh 3 in the slab on the concrete pads; and supporting an upper-layer steel mesh 9 in the slab above the lower-layer steel mesh 3 in the slab; and providing a floor top slab post-cast strip area 4 on the floor top slab casting bottom formwork 2. The method is characterized by the following steps:

[0032] The first step is to make a flat airbag, and to set an inflation and deflation nozzle and an airbag pulling handle on the side elevation of the flat airbag;

[0033] Step 2: Hang the dense steel wire mesh 8 on the left side between the lower steel mesh 3 and the upper steel mesh 9 on the left side of the post-cast zone 4 of the floor top plate;

[0034] The third step is to inflate the flat airbag and place it in the left gap formed between the lower steel mesh 3 in the slab and the bottom template 2 for pouring the floor top slab. The flat airbag is placed directly below the dense steel mesh 8 on the left side, and the inflation and deflation nozzles and the airbag pulling handle on the flat airbag are placed in the direction of the post-cast zone area 4 of the floor top slab. The multiple inflated flat airbags are connected end to end to block the left gap.

[0035] Step 4: Install the left side wooden slat 10 of the cut-off concrete on the upper steel mesh 9 in the slab just above the dense steel mesh 8 on the left side;

[0036] Step 5: Follow the steps from Step 2 to Step 4 to install the dense mesh steel wire mesh, flat airbag, and wooden slats on the right side of the post-casting zone 4 of the floor top plate; thus completing the layout of the blocking formwork on both sides of the post-casting zone 4 of the floor top plate;

[0037] Step 6: pour the floor slab concrete 5 on the left side of the post-cast zone and the floor slab concrete 6 on the right side of the post-cast zone;

[0038] Step 7: After the concrete 5 of the floor slab on the left side of the post-cast zone and the concrete 6 of the floor slab on the right side of the post-cast zone have finally set, remove the bottom formwork 2 for pouring the top slab;

[0039] Step 8: Pull out the air nozzle plug 12 on the flat airbag to deflate the flat airbag and shrink it. Then, pull the handle through the airbag to take out the shrunken flat airbag.

[0040] When the floor top plates on both sides of the post-casting joint are completed, according to relevant building specifications, the stress of the floor plates on both sides is fully released. After the expansion and contraction settlement is stable, the post-casting joint is poured, and the pouring formwork of the post-casting joint area 4 of the floor top plate is supported, and the secondary concrete pouring is carried out in the post-casting joint area 4 of the floor top plate.

[0041] On the top surface of the inflated left flat airbag 7, a fixed steel bar groove 14 is provided, and the lower steel bar mesh 3 in the plate is embedded in the fixed steel bar groove 14, especially the steel bar at the lower end of the dense steel wire mesh is embedded in the fixed steel bar groove 14, so that the left flat airbag 7 is tightly combined with the lower steel bar mesh 3 in the plate.

[0042] The multiple inflated flat air bags used to seal the left side gap between the lower steel mesh 3 in the slab and the bottom formwork 2 for casting the floor top slab are arranged in an S-shaped end-to-end connection along the left side gap direction; the multiple inflated flat air bags used to seal the right side gap between the lower steel mesh 3 in the slab and the bottom formwork 2 for casting the floor top slab are arranged in an S-shaped end-to-end connection along the right side gap direction; thereby forming a tooth-shaped interface of concrete at the gaps on both sides of the post-cast zone area 4 of the floor top slab, thereby improving the bonding quality of the secondary cast concrete in the post-cast zone area 4 of the floor top slab and the once cast floor slab concrete.

Claims

1. A method for constructing a post-cast strip of a precast floor top slab of an ultra-long building, comprising: supporting a floor top slab casting bottom formwork support (1) on a completed floor bottom slab below the precast floor top slab; setting a floor top slab casting bottom formwork (2) on the floor top slab casting bottom formwork support (1); arranging concrete pads at intervals on the floor top slab casting bottom formwork (2); supporting a lower layer steel mesh (3) in the slab on the concrete pads; and supporting an upper layer steel mesh (9) in the slab above the lower layer steel mesh (3); and providing a floor top slab post-cast strip area (4) on the floor top slab casting bottom formwork (2), characterized by the following steps: The first step is to manufacture a flat airbag, wherein an air filling and discharging nozzle and an airbag pulling handle are respectively provided on the side elevation of the flat airbag; a fixing steel bar groove (14) is provided on the top surface of the left flat airbag (7) after inflation; Step 2: Hang the left dense mesh steel wire mesh (8) between the lower steel mesh (3) and the upper steel mesh (9) in the slab on the left side of the post-cast zone area (4) of the floor top slab; The third step is to inflate the flat airbag and place it in the left gap formed between the lower steel mesh (3) in the slab and the bottom template (2) for pouring the floor top slab. The lower steel mesh (3) in the slab is embedded in the fixed steel groove (14). The flat airbag is placed directly below the dense steel mesh (8) on the left side. The inflation and deflation nozzle and the airbag pulling handle on the flat airbag are placed in the direction of the post-casting zone (4) of the floor top slab. The plurality of inflated flat airbags are connected end to end and together block the left gap. Step 4: On the upper steel mesh (9) in the plate just above the dense steel mesh (8) on the left, set the left side wooden slat (10) of the cut concrete; Step 5: Install the dense steel wire mesh, flat airbag and wooden slats on the right side of the post-casting zone (4) of the floor top plate according to the steps from step 2 to step 4; thereby completing the layout of the blocking templates on both sides of the post-casting zone (4) of the floor top plate; Step 6: pouring the floor slab concrete (5) on the left side of the post-cast strip and the floor slab concrete (6) on the right side of the post-cast strip; Step 7: After the floor slab concrete (5) on the left side of the post-casting zone and the floor slab concrete (6) on the right side of the post-casting zone have finally set, remove the floor top slab casting bottom formwork (2); Step 8: Pull out the air nozzle plug (12) on the flat air bag to deflate the flat air bag and then shrink it. Then, pull the handle through the air bag to take out the shrunken flat air bag.

2. The method for constructing a post-cast strip of a precast floor top slab of an ultra-long building according to claim 1, characterized in that: Step 9: Support the pouring template of the post-casting zone (4) of the floor top plate, and perform secondary concrete pouring on the post-casting zone (4) of the floor top plate.

3. The method for constructing a post-cast strip of a precast floor top slab of an ultra-long building according to claim 1, characterized in that: A plurality of inflated flat air bags for sealing the left side gap between the lower steel mesh sheet (3) in the slab and the bottom template (2) for pouring the floor top slab are arranged in an S-shaped end-to-end connection arrangement along the left side gap direction; a plurality of inflated flat air bags for sealing the right side gap between the lower steel mesh sheet (3) in the slab and the bottom template (2) for pouring the floor top slab are arranged in an S-shaped end-to-end connection arrangement along the right side gap direction; thereby, tooth-shaped interfaces of concrete are formed at the gaps on both sides of the post-casting zone (4) of the floor top slab, thereby improving the bonding quality of the secondary pouring concrete of the post-casting zone (4) of the floor top slab and the primary pouring floor slab concrete.

Images