CN112982783A - Concrete bidirectional stress laminated slab - Google Patents
Concrete bidirectional stress laminated slab Download PDFInfo
- Publication number
- CN112982783A CN112982783A CN202110365219.1A CN202110365219A CN112982783A CN 112982783 A CN112982783 A CN 112982783A CN 202110365219 A CN202110365219 A CN 202110365219A CN 112982783 A CN112982783 A CN 112982783A
- Authority
- CN
- China
- Prior art keywords
- steel bars
- longitudinal
- concrete
- bar
- bars
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B5/00—Floors; Floor construction with regard to insulation; Connections specially adapted therefor
- E04B5/16—Load-carrying floor structures wholly or partly cast or similarly formed in situ
- E04B5/32—Floor structures wholly cast in situ with or without form units or reinforcements
- E04B5/36—Floor structures wholly cast in situ with or without form units or reinforcements with form units as part of the floor
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/01—Reinforcing elements of metal, e.g. with non-structural coatings
- E04C5/06—Reinforcing elements of metal, e.g. with non-structural coatings of high bending resistance, i.e. of essentially three-dimensional extent, e.g. lattice girders
- E04C5/0636—Three-dimensional reinforcing mats composed of reinforcing elements laying in two or more parallel planes and connected by separate reinforcing parts
Abstract
The invention discloses a concrete bidirectional stress laminated slab, which has the following structure: the two concrete bidirectional stressed precast slabs are transversely closed, the return bent steel bars at two ends are aligned one by one, and every two corresponding return bent steel bars at two ends respectively penetrate through the annular steel bars; and the top-layer transverse steel bars are transversely arranged on the longitudinal steel bar truss of the concrete bidirectional stress prefabricated slab, and the transverse steel bars are perpendicular to the longitudinal steel bar truss. The invention can realize the bidirectional stress of the laminated slab without special operation, is integrally assembled on site, has simple production process and is beneficial to mechanical, automatic and intelligent production. Convenient transportation and low cost. Not only has good economic benefit, but also has excellent stress performance. And the site operation is convenient, the construction period is short, and the economic effect is good. More importantly, bidirectional stress can be realized without increasing supply and demand.
Description
Technical Field
The invention relates to a laminated slab, in particular to a concrete bidirectional stress laminated slab.
Background
The bidirectional plate has the problems that the problems are not effectively solved, and mechanical, automatic and intelligent production is difficult to realize when various forms of reinforcing steel bars are processed. Therefore, it is necessary to solve these technical problems to fully embody the advantages of the precast concrete assembled building. The bidirectional plate has high processing difficulty, high cost, difficult realization and low economy.
The composite floor slab is a better structural form combining prefabrication and cast-in-place concrete. The prefabricated prestressed thin plate (5-8 cm in thickness) and the upper cast-in-place concrete layer are combined into a whole and work together. The prestressed main reinforcement of the thin plate is the main reinforcement of the laminated floor slab, and the upper concrete cast-in-place layer is only provided with negative moment reinforcement and constructional reinforcement. The prestressed thin plate is used as a bottom die of a cast-in-place concrete layer, and a template does not need to be supported by the cast-in-place layer. The bottom surface of the thin plate is smooth and flat, and after plate seams are processed, the ceiling can not be plastered any more. The composite floor slab has the advantages of integrity, high rigidity, good crack resistance, no increase of reinforcing steel bar consumption, template saving and the like of a cast-in-place floor slab. Because the cast-in-place floor slab does not need to be provided with a formwork, and the large precast concrete partition boards can be simultaneously hoisted in the structural construction stage, the cast-in-place floor slab can be inserted into decoration engineering in advance, and the construction period of the whole engineering is shortened.
The floor slab has a span of less than 8 m, and can be widely used in various house construction projects such as hotels, office buildings, schools, houses, hospitals, warehouses, parking lots, multi-storey industrial plants and the like. The prestressed thin plates are different in structure according to the superposed surface and can be divided into three types: the laminated surface bears less shear stress, and the laminated surface is not provided with shear steel bars, but the upper surface of the concrete is required to be rough and scratched or some combination holes are reserved. Secondly, the shearing stress borne by the superposed surface is large, the surface of the thin plate needs to be additionally provided with shearing resistant steel bars besides rough roughening, and the diameter and the distance of the steel bars are determined by calculation. The shape of the reinforcing steel bar is wave shape, spiral shape and the shape of the triangular section formed by bending spot welding net sheets. And thirdly, the upper surface of the prefabricated thin plate is provided with a steel truss for enhancing the rigidity of the thin plate during construction and reducing the support erected below the thin plate.
The concrete composite floor slab is a part of a composite structure and is a structural form combining prefabrication and cast-in-place. In the construction process of the composite slab, a prefabricated bottom plate is firstly arranged at the bottom, the prefabricated bottom plate plays a role of a template when upper-layer concrete is poured, and then the two parts of concrete form a whole to bear load. The composite floor slab integrates the advantages of cast-in-place and prefabrication, and is a floor slab form with great development prospect.
1) From the aspect of stress, compared with a fully prefabricated assembled floor slab, the integral rigidity and the anti-seismic performance of the structure can be improved, and when the same prestressed tendons are configured, compared with the tensioned edge of the load action of the full section, the effective prestress built on the prefabricated section is larger, so that the anti-cracking performance of the structure is improved. On the premise of the same crack resistance, the using amount of the prestressed tendons can be saved.
2) From the manufacturing process, the main stressed part of the composite floor slab is manufactured in a factory, the mechanization degree is high, the quality is easy to guarantee, the production speed is high by adopting flow production, the composite floor slab can be manufactured in advance, the construction period is not occupied, and the template of the prefabricated part can be reused. The post-cast concrete takes the prefabricated bottom plate as a template, so that the workload of formwork support can be reduced compared with the full cast-in-place floor slab, the wet operation of a construction site is reduced, the condition of the construction site is improved, the construction efficiency is improved, the effect is more obvious especially under the condition of high-altitude operation or difficult formwork support, the factory prefabrication is easy to realize the manufacture of a more complex section form, and the post-cast concrete has obvious advantages of developing the bearing potential of a component and reducing the self weight of the structure. Meanwhile, the large-span laminated slab also conforms to the development direction of the building roof of the modern residence.
3) Long-term scientific experiments and engineering practice results show that the composite floor slab adopted in concrete structural engineering can obtain obvious benefits, and the using amount of the steel bars is greatly reduced when high-strength steel bars are adopted. When the hollow prefabricated section is adopted, the consumption of concrete can be saved, the construction period is correspondingly shortened, and the defects of the construction method are that the links of prefabricating, processing, transporting and hoisting are increased.
4) The section of the concrete composite floor slab consists of a prefabricated part and a cast-in-place part, and the common working performance of the prefabricated part and the cast-in-place part depends on the shearing resistance of a new superposed surface and an old superposed surface, so that the shearing resistance design of the superposed surfaces is an important part, the concrete composite floor slab has higher requirements on the construction technology content, and particularly, stricter requirements are provided for a use unit in the aspect of construction quality management.
Disclosure of Invention
The invention aims to provide a concrete bidirectional stressed laminated slab, which can realize bidirectional stress of the laminated slab without special operation, is integrally assembled on site, has simple production process and excellent stress performance.
In order to solve the problems in the prior art, the technical scheme adopted by the invention is as follows:
the concrete bidirectional stressed laminated slab mainly comprises a concrete bidirectional stressed precast slab, annular reinforcing steel bars, top transverse reinforcing steel bars and top longitudinal reinforcing steel bars, wherein the two concrete bidirectional stressed precast slabs are transversely closed, the concrete bidirectional stressed precast slab mainly comprises a precast concrete layer, two-end return reinforcing steel bars, longitudinal reinforcing steel bars and longitudinal reinforcing steel bar trusses, the two-end return reinforcing steel bars are aligned one by one, the two-two corresponding two-end return reinforcing steel bars respectively penetrate through the annular reinforcing steel bars, the annular reinforcing steel bars are arranged on the precast concrete layer, two ends of the annular reinforcing steel bars respectively extend into the precast concrete layer slabs on two sides, and the annular reinforcing steel bars extend into the precast concrete layer and cross over 2-5 longitudinal reinforcing steel bars;
the top layer transverse steel bars are transversely arranged on the longitudinal steel bar truss, the transverse steel bars are perpendicular to the longitudinal steel bar truss, the top layer transverse steel bars transversely span the transverse span of one third to one half of the adjacent concrete bidirectional stress prefabricated plates, and the top layer longitudinal steel bars are longitudinally arranged on the top layer transverse steel bars.
Furthermore, the precast concrete layer is a rectangular precast concrete slab, and return-bending steel bars, longitudinal steel bars and longitudinal steel bar trusses at two ends are arranged in the precast concrete layer;
longitudinal steel bars and longitudinal steel bar trusses are longitudinally and uniformly arranged, the longitudinal steel bar trusses are arranged at intervals of 2-5 longitudinal steel bars, return-bent steel bars at two ends are arranged on the upper portions of the longitudinal steel bars and the longitudinal steel bar trusses, the two ends of the return-bent steel bars at the two ends are tilted, the return-bent steel bars extend out of the top surface which is close to 20-50 mm of the transverse two ends of the precast concrete layer, and the return-bent steel bars gradually bend inwards and extend to the longitudinal steel bar trusses.
Further, both ends inflection reinforcing bar mainly includes the straight reinforcing bar of bottom, both ends perk reinforcing bar, tip reinforcing bar, inflection reinforcing bar, the straight reinforcing bar of middle long straight bottom, and the straight reinforcing bar both ends of bottom warp the warpage gradually and form both ends perk reinforcing bar respectively, and both ends perk reinforcing bar bends to the inflection gradually and becomes the tip reinforcing bar of buckling, and both ends tip inflection reinforcing bar extends to form the inflection reinforcing bar respectively.
Furthermore, the longitudinal steel bar truss mainly comprises bottom-layer lower-chord longitudinal bars, upper-chord longitudinal bars and web member steel bars, and the cross sections of the two bottom-layer lower-chord longitudinal bars and the cross section of the upper-chord longitudinal bar are respectively positioned on three vertexes of an isosceles triangle;
the two web member steel bars are respectively continuously bent steel bars, wherein one web member steel bar is welded with one side of the upper chord longitudinal bar at the top of the upper continuous bending and is welded with one bottom chord longitudinal bar at the bottom of the lower continuous bending;
the other web member steel bar is welded with the other side of the upper chord longitudinal bar at the top of the upper continuous bending part, and is welded with the other bottom chord longitudinal bar at the bottom of the lower continuous bending part.
The invention has the advantages and beneficial effects that:
according to the concrete bidirectional stressed laminated slab, two concrete bidirectional stressed prefabricated slabs are transversely folded, the return bent steel bars at two ends are aligned one by one, and the corresponding return bent steel bars at two ends respectively penetrate through the annular steel bars; the top layer transverse steel bars are transversely arranged on the longitudinal steel bar truss of the concrete bidirectional stress prefabricated slab, and the transverse steel bars are perpendicular to the longitudinal steel bar truss, so that bidirectional stress of the laminated slab can be realized without special operation, integral assembly is carried out on site, the production process is simple, and mechanical, automatic and intelligent production is facilitated. Convenient transportation and low cost. Not only has good economic benefit, but also has excellent stress performance. And the site operation is convenient, the construction period is short, the economic effect is good, the complex operation in the construction process is avoided, and the manufacturing cost is greatly reduced. More importantly, bidirectional stress can be realized without increasing supply and demand.
Drawings
FIG. 1 is a schematic view of the overall structure of a concrete bidirectional stressed composite slab;
FIG. 2 is a schematic plan view of a concrete bidirectional stressed composite slab without top layer reinforcing steel bars;
FIG. 3 is a schematic view of an end face of a concrete bidirectional stressed composite slab without a top layer of steel bars;
FIG. 4 is a schematic top plan view of the concrete bidirectional stressed precast slab;
FIG. 5 is a schematic top view of the concrete bidirectional stressed precast slab;
fig. 6 is a schematic view of a structure of a steel bar bent back at two ends.
In the figure: 1 is a concrete bidirectional stress precast slab; 2 is an annular steel bar; 3 is a top layer transverse steel bar; and 4, top longitudinal steel bars. 1-1 is a precast concrete layer; 1-2 is a steel bar with two bent ends; 1-3 are longitudinal steel bars; 1-4 are longitudinal steel bar trusses. 1-2-1 is a bottom straight steel bar; 1-2-2 is a reinforcing steel bar with two raised ends; 1-2-3 is an end bending reinforcing steel bar; 1-2-4 are return bend steel bars. 1-4-1 is a bottom layer lower chord longitudinal bar; 1-4-2 is upper chord longitudinal bar; 1-4-3 are web member reinforcing steel bars.
Detailed Description
In order to further illustrate the present invention, the following detailed description of the present invention is given with reference to the accompanying drawings and examples, which should not be construed as limiting the scope of the present invention.
As shown in figures 1-3, the concrete bidirectional stressed laminated slab mainly comprises concrete bidirectional stressed precast slabs 1, annular reinforcing steel bars 2, top-layer transverse reinforcing steel bars 3 and top-layer longitudinal reinforcing steel bars 4, wherein the two concrete bidirectional stressed precast slabs 1 are transversely gathered. As shown in fig. 4 and 5, the concrete bidirectional stressed precast slab 1 mainly comprises precast concrete layers 1-1, two ends of return bent steel bars 1-2, longitudinal steel bars 1-3 and longitudinal steel bar trusses 1-4, wherein the two ends of return bent steel bars 1-2 are aligned one by one, every two corresponding two ends of return bent steel bars 1-2 respectively pass through annular steel bars 2, the annular steel bars 2 are arranged on the precast concrete layers 1-1, two ends of the annular steel bars 2 respectively extend into the precast concrete layers 1-1 on two sides, and the annular steel bars 2 extend into the precast concrete layers 1-1 to stride over 2-5 longitudinal steel bars 1-3. The top layer transverse steel bars 3 are transversely arranged on the longitudinal steel bar trusses 1-4, the transverse steel bars 3 are perpendicular to the longitudinal steel bar trusses 1-4, the top layer transverse steel bars 3 transversely span one third to one half of the transverse span of the adjacent concrete bidirectional stress prefabricated plates 1, and the top layer longitudinal steel bars 4 are longitudinally arranged on the top layer transverse steel bars 3.
As shown in fig. 4 and 5, the precast concrete layer 1-1 is a rectangular precast concrete slab, and return steel bars 1-2, longitudinal steel bars 1-3 and longitudinal steel bar trusses 1-4 are arranged at two ends in the precast concrete layer 1-1; the longitudinal steel bars 1-3 and the longitudinal steel bar trusses 1-4 are longitudinally and uniformly arranged, one longitudinal steel bar truss 1-4 is arranged every 2-5 longitudinal steel bars 1-3, return-bent steel bars 1-2 at two ends are arranged on the upper portions of the longitudinal steel bars 1-3 and the longitudinal steel bar trusses 1-4, two ends of the return-bent steel bars 1-2 at two ends are tilted, extend out of the top surface which is 20-50 mm close to the transverse two ends of the precast concrete layer 1-1, and are gradually bent inwards and extend to the longitudinal steel bar trusses 1-4.
As shown in fig. 6, the two-end bent rebars 1-2 mainly include bottom straight rebars 1-2-1, two-end tilted rebars 1-2-2, end bent rebars 1-2-3, and bent rebars 1-2-4, the middle is long straight bottom straight rebars 1-2-1, two ends of the bottom straight rebars 1-2-1 gradually warp upward to form two-end tilted rebars 1-2-2, two-end tilted rebars 1-2-2 gradually bend back to form end bent rebars 1-2-3, and two-end bent rebars 1-2-3 extend back to form bent rebars 1-2-4.
As shown in fig. 5, the longitudinal steel bar truss 1-4 mainly comprises bottom-layer lower-chord longitudinal bars 1-4-1, upper-chord longitudinal bars 1-4-2 and web member steel bars 1-4-3, and the cross sections of two bottom-layer lower-chord longitudinal bars 1-4-1 and one upper-chord longitudinal bar 1-4-2 are respectively located on three vertexes of an isosceles triangle;
the two web member reinforcing steel bars 1-4-3 are respectively continuous bending reinforcing steel bars, wherein one web member reinforcing steel bar 1-4-3 is welded with one side of the upper chord longitudinal bar 1-4-2 at the top of the upper continuous bending, and is welded with one lower chord longitudinal bar 1-4-1 at the bottom of the upper chord longitudinal bar at the top of the lower continuous bending;
the other web member reinforcing steel bar 1-4-3 is welded with the other side of the upper chord longitudinal bar 1-4-2 at the top of the upper continuous bending, and is welded with the other bottom chord longitudinal bar 1-4-1 at the bottom of the lower continuous bending.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (4)
1. Two-way atress superimposed sheet of concrete, its characterized in that: the prefabricated concrete slab mainly comprises a concrete bidirectional stressed prefabricated slab (1), annular steel bars (2), top transverse steel bars (3) and top longitudinal steel bars (4), wherein the two concrete bidirectional stressed prefabricated slabs (1) are transversely closed, the concrete bidirectional stressed prefabricated slab (1) mainly comprises a prefabricated concrete layer (1-1), two-end bent steel bars (1-2), longitudinal steel bars (1-3) and longitudinal steel bar trusses (1-4), the two-end bent steel bars (1-2) are aligned one by one, the two-end bent steel bars (1-2) corresponding in pairs respectively penetrate through the annular steel bars (2), the annular steel bars (2) are arranged on the prefabricated concrete layer (1-1), the two ends of the annular steel bars (2) respectively extend towards the prefabricated concrete layer (1-1) on the two sides, and the annular steel bars (2) extend into the prefabricated concrete layer (1-1) to stride over 2-5 longitudinal steel bars (1-3) ) (ii) a
The top-layer transverse steel bars (3) are transversely arranged on the longitudinal steel bar trusses (1-4), the transverse steel bars (3) are perpendicular to the longitudinal steel bar trusses (1-4), the top-layer transverse steel bars (3) transversely span one third to one half of the transverse span of the adjacent concrete bidirectional stress prefabricated plates (1), and the top-layer longitudinal steel bars (4) are longitudinally arranged on the top-layer transverse steel bars (3).
2. The concrete bidirectional stressed laminated slab as claimed in claim 1, wherein: the precast concrete layer (1-1) is a rectangular precast concrete slab, and the precast concrete layer (1-1) is internally provided with two ends of return bent steel bars (1-2), longitudinal steel bars (1-3) and longitudinal steel bar trusses (1-4);
longitudinal steel bars (1-3) and longitudinal steel bar trusses (1-4) are longitudinally and uniformly arranged, one longitudinal steel bar truss (1-4) is arranged at intervals of 2-5 longitudinal steel bars (1-3), two ends of the longitudinal steel bar (1-3) and the two ends of the longitudinal steel bar truss (1-4) are bent back, the two ends of the.
3. The concrete bidirectional stressed laminated slab as claimed in claim 2, wherein: the two-end bent steel bar (1-2) mainly comprises a bottom straight steel bar (1-2-1), two-end upwarping steel bars (1-2-2), end bending steel bars (1-2-3) and bent steel bars (1-2-4), a long straight bottom straight steel bar (1-2-1) is arranged in the middle, two ends of the bottom straight steel bar (1-2-1) are gradually upwards warped to form two-end upwarping steel bars (1-2-2) respectively, the two-end upwarping steel bars (1-2-2) are gradually bent back to form an end bending steel bar (1-2-3), and the two-end bending steel bars (1-2-3) are respectively formed by extending back.
4. The concrete bidirectional stressed laminated slab as claimed in claim 2, wherein: the longitudinal steel bar truss (1-4) mainly comprises bottom-layer lower chord longitudinal bars (1-4-1), upper chord longitudinal bars (1-4-2) and web member steel bars (1-4-3), and the cross sections of the two bottom-layer lower chord longitudinal bars (1-4-1) and the upper chord longitudinal bar (1-4-2) are respectively positioned on three vertexes of an isosceles triangle;
the two web member reinforcing steel bars (1-4-3) are respectively continuous bending reinforcing steel bars, wherein one web member reinforcing steel bar (1-4-3) is welded with one side of the upper chord longitudinal bar (1-4-2) at the top of the upper continuous bending, and is welded with one bottom layer lower chord longitudinal bar (1-4-1) at the top of the lower continuous bending;
the other web member steel bar (1-4-3) is welded with the other side of the upper chord longitudinal bar (1-4-2) at the top of the upper continuous bending, and is welded with the other bottom chord longitudinal bar (1-4-1) at the bottom of the lower continuous bending.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110365219.1A CN112982783A (en) | 2021-04-06 | 2021-04-06 | Concrete bidirectional stress laminated slab |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110365219.1A CN112982783A (en) | 2021-04-06 | 2021-04-06 | Concrete bidirectional stress laminated slab |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112982783A true CN112982783A (en) | 2021-06-18 |
Family
ID=76339282
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110365219.1A Withdrawn CN112982783A (en) | 2021-04-06 | 2021-04-06 | Concrete bidirectional stress laminated slab |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112982783A (en) |
-
2021
- 2021-04-06 CN CN202110365219.1A patent/CN112982783A/en not_active Withdrawn
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN202416650U (en) | Self-supporting ribbed reinforced steel bar truss concrete composite slab | |
| WO2013166658A1 (en) | Method of casting in-situ steel wire mesh cement slab with spliced rack and suspended formwork | |
| CN112982142A (en) | Cold-formed thin-walled steel web plate combined PC box girder | |
| CN110005109A (en) | A kind of open flume type prestressed concrete overlapped slab | |
| CN111794423A (en) | Steel-concrete combined beam structure, building and construction method | |
| CN208039577U (en) | Half prefabricated prestressed concrete floor slab of figure of eight steel bar girder | |
| CN112982783A (en) | Concrete bidirectional stress laminated slab | |
| CN109853873A (en) | Overlap concrete bidirectional stress insulation roof slab | |
| CN202430877U (en) | Continuous superposed beam used for steel structure | |
| CN101294431B (en) | Construction method for steel-concrete composite truss floor | |
| CN209817217U (en) | Bidirectional floor slab with superposed concrete reinforcing steel rings | |
| CN212506971U (en) | Laminated slab for building | |
| CN209817218U (en) | Laminated concrete steel step opening spliced bidirectional floor slab | |
| CN111101628B (en) | FRP sheet material connecting structure and method for precast concrete beam plate system | |
| CN209817216U (en) | Superimposed concrete bidirectional stress heat insulation roof tooth groove type prefabricated slab | |
| CN111663696A (en) | Formwork-free self-bearing prefabricated rib beam concrete hollow laminated slab | |
| CN218881308U (en) | Self-bearing prestressed net rib plate | |
| CN213774033U (en) | Built-in steel bar truss of fabricated floor | |
| CN209975879U (en) | Superimposed concrete bidirectional stress thermal insulation roof board | |
| CN219622069U (en) | Assembled light steel strip hollow steel bar truss concrete strip superposed two-way floor slab | |
| CN219196452U (en) | Assembled self-bearing prestress plate | |
| CN214006259U (en) | Promote truss-like reinforcing bar structure of special-shaped column structure anti-seismic performance | |
| CN217000411U (en) | Truss reinforced concrete superimposed sheet | |
| CN219196451U (en) | Assembled self-bearing prestressed rib floor | |
| CN220080450U (en) | Micro-concrete ribbed 3-limb steel bar truss composite floor slab |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20210618 |
|
| WW01 | Invention patent application withdrawn after publication |