CN220953832U - Assembled connection node of steel pipe concrete superposed column and combined steel beam - Google Patents
Assembled connection node of steel pipe concrete superposed column and combined steel beam Download PDFInfo
- Publication number
- CN220953832U CN220953832U CN202322572523.0U CN202322572523U CN220953832U CN 220953832 U CN220953832 U CN 220953832U CN 202322572523 U CN202322572523 U CN 202322572523U CN 220953832 U CN220953832 U CN 220953832U
- Authority
- CN
- China
- Prior art keywords
- steel
- node
- concrete
- plate
- column
- 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.)
- Active
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 180
- 239000010959 steel Substances 0.000 title claims abstract description 180
- 239000004567 concrete Substances 0.000 title claims abstract description 72
- 239000002131 composite material Substances 0.000 claims abstract description 49
- 239000000835 fiber Substances 0.000 claims description 9
- 230000000149 penetrating effect Effects 0.000 claims description 6
- 239000011148 porous material Substances 0.000 claims description 4
- 238000010276 construction Methods 0.000 abstract description 10
- 238000010008 shearing Methods 0.000 abstract description 5
- 230000006835 compression Effects 0.000 abstract description 3
- 238000007906 compression Methods 0.000 abstract description 3
- 210000001503 joint Anatomy 0.000 description 3
- 238000009417 prefabrication Methods 0.000 description 3
- 239000004568 cement Substances 0.000 description 2
- 238000009415 formwork Methods 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000004080 punching Methods 0.000 description 2
- 239000011150 reinforced concrete Substances 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000009435 building construction Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229920006253 high performance fiber Polymers 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 230000002262 irrigation Effects 0.000 description 1
- 238000003973 irrigation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A30/00—Adapting or protecting infrastructure or their operation
- Y02A30/30—Adapting or protecting infrastructure or their operation in transportation, e.g. on roads, waterways or railways
Landscapes
- Rod-Shaped Construction Members (AREA)
Abstract
The utility model provides an assembled connecting node of a steel tube concrete composite column and a combined steel beam, which relates to the technical field of building structures and comprises a middle node, the steel tube concrete composite column and the combined beam, wherein the steel tube concrete composite column and the middle node are assembled by adopting embedded screws, so that the integrity of the node can be enhanced to effectively resist relative sliding and deformation; the channel steel of the combined beam is welded and fixed with the middle node, so that the middle node becomes a part of the combined beam, the integrity of the node can be further enhanced, the support of cast-in-place concrete is reduced, and the construction is convenient; meanwhile, through the combined action of the longitudinal bars and the stirrups in the composite beam, the tensile property and the concrete compression property of steel can be fully exerted, the bearing capacity is improved, the node connection is more reliable, and the load transfer between the steel pipe concrete composite column and the composite beam is ensured, so that the problems of weak bearing capacity, low shearing bearing capacity and poor connection stability of the existing steel pipe concrete column connection node are solved.
Description
Technical Field
The utility model relates to the technical field of building structures, in particular to an assembled connecting node of a concrete filled steel tube composite column and a combined steel beam.
Background
Because the steel pipe and the concrete have good cooperative working characteristics, the steel pipe can effectively restrict the concrete from deforming axially, and meanwhile, the concrete can also effectively avoid the steel pipe from buckling inwards locally, so that the steel pipe concrete meets the requirements of modern building construction and industrialization, and is widely applied. However, for the structure with larger load and span, the node structure of the steel tube concrete column has the problems of weak bearing capacity, low shearing bearing capacity, poor connection stability and the like, so that the application is limited to a certain extent, and the advantages of the concrete beam and the steel tube concrete column cannot be fully exerted.
Disclosure of utility model
The utility model discloses an assembled connecting node of a steel tube concrete composite column and a combined steel beam, and aims to solve the problems of weak bearing capacity, low shearing bearing capacity and poor connecting stability of the existing connecting node of the steel tube concrete column.
The utility model adopts the following scheme:
The assembled connecting node comprises a middle node, a steel pipe concrete superposed column and a combined beam, wherein perforated steel plates are arranged around the middle node, and an upper end plate and a lower end plate are respectively arranged at two axial ends of the perforated steel plates; the steel tube concrete superposed column comprises a steel tube, an upper steel plate, a lower steel plate, an embedded screw, a counter-pulling screw and a flying nut, wherein the upper steel plate and the lower steel plate are respectively welded at two axial ends of the steel tube, the embedded screw is connected with the upper steel plate, and the embedded screw sequentially penetrates through the lower end plate and the upper end plate from bottom to top to be connected with a lower steel plate of another steel tube concrete superposed column; a plurality of screw holes are formed along the circumferential side wall of the steel pipe, and the opposite-pull screws are arranged in the screw holes in a penetrating manner and are locked through the ring nut; the combined beam comprises channel steel, longitudinal ribs, stirrups and precast slabs, wherein the channel steel is welded and fixed with the perforated steel plate, the longitudinal ribs penetrate through the middle nodes and the channel steel, the stirrups are arranged in the channel steel and matched with the longitudinal ribs, and the precast slabs are paved on the channel steel; and concrete is filled from the inner cavity of the steel pipe to the middle node and the channel steel integrally, and the outer wall of the steel pipe is solidified with a high-ductility fiber concrete shell.
As a further improvement, the upper end plate, the lower end plate, the upper steel plate and the lower steel plate are all in a shape like a Chinese character 'hui'.
As a further improvement, the section of the channel steel is U-shaped.
As a further improvement, a plurality of embedded screws are equidistantly arranged along the circumferential direction of the upper steel plate, the lower steel plate is provided with mounting holes corresponding to the embedded screws, and the upper end plate and the lower end plate are provided with through holes corresponding to the embedded screws.
As a further improvement, the side wall of the steel tube concrete superposed column is provided with an operation groove corresponding to the embedded screw, and the operation groove is used for screwing a nut into the embedded screw.
As a further improvement, the middle node is square, the perforated steel plate is provided with holes along four sides, and the channel steel is just opposite to the holes.
As a further improvement, the steel pipe is square, and the opposite-pulling screw is used for being connected with two opposite surfaces.
By adopting the technical scheme, the utility model can obtain the following technical effects:
the steel pipe concrete superposed column and the middle joint are connected in an assembly mode by the embedded screw rod, the embedded screw rod sequentially penetrates through the lower end plate and the upper end plate from the lower superposed column to be connected with a lower steel plate of the upper superposed column, the integrity of the joint can be enhanced, relative sliding and deformation can be effectively resisted, and the mechanical property is excellent; the channel steel and the middle node of the composite beam are welded and fixed, so that the middle node becomes a part of the composite beam, the support of cast-in-place concrete can be reduced, and the construction is convenient. In addition, through the combined action of the longitudinal bars and the stirrups, the integrity of the composite beam and the steel pipe concrete superposed column is further enhanced, so that the composite beam can fully exert the tensile and concrete compression characteristics of steel, the bearing capacity is improved, and the node connection is more reliable; the method ensures the load transfer between the steel tube concrete composite column and the composite beam, and has good mechanical properties, thereby solving the problems of weak bearing capacity, low shearing bearing capacity and poor connection stability of the traditional steel tube concrete column.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some examples of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of an embodiment of the present utility model;
FIG. 2 is a schematic view of an intermediate node to composite beam connection in accordance with one embodiment of the present utility model;
Fig. 3 is a schematic structural view of a concrete filled steel tube composite column according to an embodiment of the present utility model in a prefabrication stage.
Icon: 1-an intermediate node; 11-perforated steel sheet; 12-an upper end plate; 13-a lower end plate;
2-a steel tube concrete superposed column; 21-a steel pipe; 22-upper steel plate; 23-lower steel plate; 231-mounting holes; 24-embedding a screw; 25-opposite-pulling screw rods; 26-a ring nut; 27-a high-ductility fiber concrete casing; 28-an operation slot;
3-composite beams; 31-channel steel; 32-longitudinal ribs; 33-stirrups; 34-prefabricated panels.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments. All other embodiments, based on the embodiments of the utility model, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the utility model. Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, based on the embodiments of the utility model, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the utility model.
Examples
Referring to fig. 1 to 3, the embodiment provides an assembled connection node of a concrete filled steel tube composite column and a composite steel beam, which comprises a middle node 1, a concrete filled steel tube composite column 2 and a composite beam 3, wherein an open-pore steel plate 11 is arranged around the middle node 1, and two axial ends of the open-pore steel plate 11 are respectively provided with an upper end plate 12 and a lower end plate 13; the steel tube concrete composite column 2 comprises a steel tube 21, an upper steel plate 22, a lower steel plate 23, an embedded screw 24, a counter screw 25 and a suspension ring nut 26, wherein the upper steel plate 22 and the lower steel plate 23 are respectively welded at two axial ends of the steel tube 21, the embedded screw 24 is connected with the upper steel plate 22, and the embedded screw 24 sequentially penetrates through the lower end plate 13 and the upper end plate 12 from bottom to top to be connected with the lower steel plate 23 of the other steel tube concrete composite column 2; a plurality of screw holes are formed along the circumferential side wall of the steel pipe 21, and opposite-pull screws 25 are arranged in the screw holes in a penetrating manner and are locked through ring nuts 26; the composite beam 3 comprises a channel steel 31, longitudinal ribs 32, stirrups 33 and precast slabs 34, wherein the channel steel 31 is welded and fixed with the perforated steel plate 11, the longitudinal ribs 32 penetrate through the middle node 1 and the channel steel 31, the stirrups 33 are arranged in the channel steel 31 and matched with the longitudinal ribs 32, and the precast slabs 34 are paved on the channel steel 31; the steel pipe 21 is entirely filled with concrete from the inner cavity to the intermediate joint 1 and the channel steel 31, and the outer wall of the steel pipe 21 is solidified with a high-ductility fiber concrete shell 27. The high-ductility fiber concrete is a novel high-performance fiber toughened cement-based composite material which comprises cement, sand, water, mineral admixture and chemical admixture as a matrix, uses high-strength high-elastic modulus short fiber with the fiber volume admixture of less than 3% as a toughening material, and has strain hardening property and multiple stable cracking characteristics after hardening.
It should be noted that, the steel pipe concrete composite column 2 and the middle node 1 are connected in an assembled manner by adopting the embedded screw 24, the embedded screw 24 sequentially passes through the lower end plate 13 and the upper end plate 12 from the lower composite column to be connected with the lower steel plate 23 of the upper composite column, so that the integrity of the node can be enhanced, relative sliding and deformation can be effectively resisted, and the mechanical property is excellent; the channel steel 31 of the composite beam 3 is welded and fixed with the intermediate node 1, so that the intermediate node 1 becomes a part of the composite beam 3, the support of cast-in-place concrete can be reduced, and the construction is convenient. In addition, through the combined action of the longitudinal ribs 32 and the stirrups 33, the integrity of the composite beam 3 and the steel pipe concrete composite column 2 is further enhanced, so that the composite beam 3 can fully exert the tensile and concrete compression characteristics of steel, the bearing capacity is improved, and the node connection is more reliable; the load transmission between the steel tube concrete composite column 2 and the composite beam 3 is ensured, and the steel tube concrete composite column has good mechanical properties, so that the problems of weak bearing capacity, low shearing bearing capacity and poor connection stability of the traditional steel tube concrete column are solved.
In addition, the steel pipe concrete superposed column 2 is used as a supporting platform of the combined beam 3, the combined beam 3 is used as a supporting platform of the precast slab 34, and the precast slab 34 is used as a bottom die of the reinforced concrete floor slab, a supporting platform and a steel bar binding operation platform, so that the construction portability is greatly improved. The node has simple structure and convenient construction, and can effectively realize the connection of the steel pipe concrete composite column 2 and the composite beam 3, so that the node of the steel pipe concrete composite column 2 has universal applicability in prefabricated assembly type buildings and has wide application prospect. Specifically, the load of the connecting structure is transferred to the precast slab 34, the composite beam 3, the middle node 1, the embedded screw 24, the upper steel plate 22 and the lower steel plate 23, the steel pipe 21, the cast-in-situ core concrete and the high-ductility fiber concrete shell 27.
Preferably, the upper end plate 12, the lower end plate 13, the upper steel plate 22 and the lower steel plate 23 are all in a shape like a Chinese character 'hui', the middle node 1 is square and the steel tube 21 is square, the perforated steel plate 11 is provided with holes along four sides, the channel steel 31 is U-shaped and is arranged opposite to the holes, and the opposite pull screws 25 are used for being connected with two opposite surfaces, so that the internal strength of the steel tube 21 is enhanced.
Based on the above embodiment, in an alternative embodiment of the present utility model, a plurality of embedded screws 24 are equidistantly configured along the circumferential direction of the upper steel plate 22, the lower steel plate 23 is provided with mounting holes 231 corresponding to the embedded screws 24, and the upper end plate 12 and the lower end plate 13 are provided with through holes corresponding to the embedded screws 24. The side wall of the steel pipe concrete superposed column 2 is provided with an operation groove 28 corresponding to the embedded screw 24, so that a nut is screwed into the embedded screw 24, the nut is conveniently locked from the side surface, and the construction efficiency is improved.
The construction method of the embodiment comprises the following two stages:
A. factory prefabrication stage:
1. Prefabricating a steel pipe concrete superposed column 2: (1) Punching the square steel tube 21 for threading the split screws 25 according to the calculated data and the selected component size; (2) Welding two ends of the square steel tube 21 with the upper and lower steel plates in the shape of a Chinese character 'Hui'; (3) A counter-pulling screw 25 is inserted through the steel pipe 21 and is locked with a flying nut 26 at both ends; and (4) making a template according to the size of the column. (5) Placing the prepared steel structure part into a template to cast high-ductility fiber concrete; (6) removing the die after curing. Note that, for the upper and lower steel plates 23, the upper steel plate 22 needs to be embedded with high-strength screws, the lower steel plate 23 needs to be reserved with mounting holes 231, and meanwhile, an operation groove 28 needs to be reserved during formwork pouring.
2. Prefabricating an intermediate node 1: (1) According to the calculated data and the selected size of the component, manufacturing a side steel plate and an upper and lower U-shaped end plate; (2) Punching side steel plates for penetrating through the longitudinal ribs 32, and reserving through holes for screws to penetrate through by the upper end plate 13 and the lower end plate 13; (3) The perforated steel plate 11 is welded to the upper end plate 12, the lower end plate 13, and the channel steel 31.
3. Prefabricated panels 34 are prefabricated: and paving templates in a factory to finish the irrigation and maintenance of the prefabricated hollow slab.
B. And (3) in the field construction stage: this stage is after the factory prefabrication of the steel pipe concrete composite column 2, the middle joint 1 and the prefabricated plate 34 is completed and transported to the site, and the assembly construction of the assembly type connecting joint is started. First, the intermediate joint 1 is placed on the pre-buried screw 24 of the lower superposed column, and the arrangement of the penetrating longitudinal bars 32 and the bundling of the stirrups 33 are completed. And then, penetrating the embedded screw 24 of the lower superposed column through the middle joint 1 and connecting with the mounting hole 231 of the lower steel plate 23 of the upper superposed column, then placing the precast slab 34 on the channel steel 31, laying slab ribs and supporting a formwork, finally, completing pouring maintenance of the reinforced concrete floor slab, the combined beam 3 and the concrete-filled steel tube superposed column 2 cast-in-place core concrete, and completing the site construction stage when the concrete strength reaches the design requirement.
The above is only a preferred embodiment of the present utility model, and the protection scope of the present utility model is not limited to the above examples, and all technical solutions belonging to the concept of the present utility model belong to the protection scope of the present utility model.
Claims (7)
1. The utility model provides an assembled connected node of steel pipe concrete coincide post and combination girder steel which characterized in that includes:
The middle node is provided with an open-pore steel plate at the periphery, and an upper end plate and a lower end plate are respectively arranged at the two axial ends of the open-pore steel plate;
the steel pipe concrete superposed column comprises a steel pipe, an upper steel plate, a lower steel plate, an embedded screw, a counter-pulling screw and a flying nut, wherein the upper steel plate and the lower steel plate are respectively welded at two axial ends of the steel pipe, the embedded screw is connected with the upper steel plate, and the embedded screw sequentially penetrates through the lower end plate and the upper end plate from bottom to top to be connected with the lower steel plate of another steel pipe concrete superposed column; a plurality of screw holes are formed along the circumferential side wall of the steel pipe, and the opposite-pull screws are arranged in the screw holes in a penetrating manner and are locked through the ring nut;
The combined beam comprises a channel steel, longitudinal ribs, stirrups and precast slabs, wherein the channel steel is welded and fixed with the perforated steel plate, the longitudinal ribs penetrate through the middle nodes and the channel steel, the stirrups are arranged in the channel steel and are matched with the longitudinal ribs, and the precast slabs are laid on the channel steel;
And concrete is filled from the inner cavity of the steel pipe to the middle node and the channel steel integrally, and the outer wall of the steel pipe is solidified with a high-ductility fiber concrete shell.
2. The assembled connection node of the steel pipe concrete composite column and the combined steel beam according to claim 1, wherein the upper end plate, the lower end plate, the upper steel plate and the lower steel plate are all in a shape of a Chinese character 'hui'.
3. The assembled connection node of the steel tube concrete composite column and the combined steel beam according to claim 1, wherein the section of the channel steel is U-shaped.
4. The assembled connecting node of the steel tube concrete composite column and the combined steel beam according to claim 1, wherein a plurality of embedded screws are equidistantly arranged along the circumferential direction of the upper steel plate, the lower steel plate is provided with mounting holes corresponding to the embedded screws, and the upper end plate and the lower end plate are provided with through holes corresponding to the embedded screws.
5. The assembled connection node of the steel tube concrete composite column and the combined steel beam according to claim 4, wherein an operation groove is formed in the side wall of the steel tube concrete composite column corresponding to the embedded screw for screwing a nut into the embedded screw.
6. The assembled connecting node of the steel tube concrete composite column and the combined steel beam according to claim 1, wherein the middle node is square, the perforated steel plate is provided with holes along four sides, and the channel steel is arranged opposite to the holes.
7. The assembled connection node of a concrete filled steel tube composite column and a composite steel beam according to claim 1, wherein the steel tube is square, and the split screws are used for connecting two opposite surfaces.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322572523.0U CN220953832U (en) | 2023-09-21 | 2023-09-21 | Assembled connection node of steel pipe concrete superposed column and combined steel beam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322572523.0U CN220953832U (en) | 2023-09-21 | 2023-09-21 | Assembled connection node of steel pipe concrete superposed column and combined steel beam |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220953832U true CN220953832U (en) | 2024-05-14 |
Family
ID=91013626
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202322572523.0U Active CN220953832U (en) | 2023-09-21 | 2023-09-21 | Assembled connection node of steel pipe concrete superposed column and combined steel beam |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN220953832U (en) |
-
2023
- 2023-09-21 CN CN202322572523.0U patent/CN220953832U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108755963B (en) | Partially prefabricated assembled type steel reinforced concrete giant frame structure and construction method | |
| CN108824818B (en) | Construction method of assembled concrete filled steel tube frame-shear wall structure system | |
| CN108678218B (en) | Assembly type concrete shear wall based on multipurpose thin-wall steel pipe and construction method thereof | |
| CN108755964B (en) | Partially prefabricated assembly type steel concrete mixing column and construction method | |
| CN114045967A (en) | Fabricated floor, building structure with fabricated floor and construction method of building structure | |
| CN109680833B (en) | Self-supporting prefabricated steel reinforced concrete wall plate component, wall, structural system and manufacturing method | |
| CN113789861B (en) | Assembly type connecting joint of corrugated plate-ECC column and concrete beam and construction method thereof | |
| CN217630848U (en) | Prefabricated steel pipe joint concrete column component | |
| CN220953832U (en) | Assembled connection node of steel pipe concrete superposed column and combined steel beam | |
| CN116752631A (en) | Prefabricated honeycomb type steel reinforced concrete beam column joint and construction method | |
| CN110894744A (en) | Truss wallboard for manufacturing shear wall, shear wall manufactured by using truss wallboard and manufacturing method of shear wall | |
| CN216840803U (en) | Temporary support structure for replacing shear wall concrete | |
| CN115928882A (en) | Assembled composite structure hybrid connection node suitable for coastal region | |
| CN115434425A (en) | Lattice type steel reinforced concrete prefabricated beam column joint and method | |
| CN215106427U (en) | Hollow superimposed sheet of enhancement steel pipe truss prestressing force | |
| CN211923210U (en) | Truss wallboard for manufacturing shear wall and shear wall manufactured by using same | |
| CN114482267A (en) | Assembled hollow corrugated sandwich concrete filled steel tube combined frame structure system | |
| CN114108808A (en) | PVC-FRP (polyvinyl chloride-fiber reinforced plastic) pipe concrete column and concrete composite beam combined structure with adjustable connecting nodes and installation method thereof | |
| CN210105041U (en) | Self-supporting prefabricated steel reinforced concrete wallboard component, wall and structural system | |
| CN219261339U (en) | Lattice type steel reinforced concrete precast beam column node | |
| CN116497976B (en) | Double-steel-plate-concrete combined shear wall connection node structure and connection construction method | |
| CN221030828U (en) | Shear wall of steel tube concrete hidden column formwork | |
| CN220565524U (en) | Large-width prestressed reinforcement truss composite floor slab | |
| CN219365020U (en) | Combined assembly type concrete shear wall | |
| CN215888962U (en) | Thin-bottom groove type prestressed concrete superposed beam |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |