CN109469259B - Replaceable partially assembled steel-concrete double-sided combined action beam - Google Patents
Replaceable partially assembled steel-concrete double-sided combined action beam Download PDFInfo
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- CN109469259B CN109469259B CN201811063626.1A CN201811063626A CN109469259B CN 109469259 B CN109469259 B CN 109469259B CN 201811063626 A CN201811063626 A CN 201811063626A CN 109469259 B CN109469259 B CN 109469259B
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C3/00—Structural elongated elements designed for load-supporting
- E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
- E04C3/29—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures
- E04C3/293—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures the materials being steel and concrete
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Abstract
A replaceable partially assembled steel-concrete double-sided combined action beam belongs to the field of combined structures. The upper concrete slab of the combined beam is a cast-in-situ slab, the lower concrete slab is a precast slab, and the precast slab and the triangular steel plate stopper are integrally precast. During construction, the lower concrete plate and the triangular steel plate stopper are integrally arranged at the lower part of the lower flange of the steel beam, the lower flange of the steel beam is connected with the lower flange of the steel beam through bolts, gaps between the lower concrete plate and the steel column are filled with grouting materials, and finally the upper concrete plate is poured. And in the later period, if the lower concrete plate is damaged or the bearing capacity of the combined beam needs to be improved, the lower concrete plate can be removed and a new concrete plate can be replaced. The invention not only has the excellent performance of the traditional composite beam, but also can fully exert the respective advantages of steel and concrete, improve the utilization rate of materials, strengthen the cracking resistance, rigidity and bearing capacity of the composite beam, and has reliable performance, low cost, convenient construction, quick repair after earthquake and particular suitability for large-span and heavy-load structures.
Description
Technical field:
the invention belongs to the technical field of combined structures, and relates to a replaceable partially assembled steel-concrete double-sided combined action beam.
The background technology is as follows:
the current construction engineering is increasingly applied in the aspects of large span and heavy load, if the traditional reinforced concrete beam is adopted, the section height of the beam can be very large, the indoor clear height is influenced, the dead weight of the beam is also very large, the construction is difficult, and the construction is uneconomical. If the traditional steel-concrete composite beam is adopted, the problem can be solved well, but the lower flange of the steel beam is severely stressed and possibly unstable due to the large hogging moment existing at the support in the common continuous composite beam; the upper concrete plate is easy to be pulled and cracked, the thickness of the lower flange of the steel beam and the height of the beam are often determined by a hogging moment area, so that the utilization rate of materials is low, and the steel consumption is large. In order to solve the problem, although some technologies for improving the cracking resistance have been developed at present, the technologies are complex, the cost is high, the effect is very little, and the repair is very difficult after the damage. Therefore, how to improve the bearing capacity of the common composite beam and the material utilization rate, and meanwhile, the composite beam has certain replaceability, is convenient for quick repair after earthquake, is suitable for the development trend of the current green building industrialization construction, and is a challenge which must be faced in the scientific research and engineering practice of the composite structure system. Therefore, to overcome the above problems, development of a new green composite member that can be adapted for large span, heavy load, and replacement is urgently required.
The invention comprises the following steps:
the invention aims to provide a set of replaceable partially assembled steel-concrete double-sided combined action beam.
The proposal of the invention is as follows:
the replaceable partially assembled steel-concrete double-sided combined action beam is characterized by comprising an upper concrete slab (1), an upper steel bar (2), a steel beam (4), bolts (3), a first bolt sleeve group (9), a second bolt sleeve group (7), a triangular steel plate stopper (6), a lower precast concrete slab (5) and a lower steel bar (8); the upper concrete plate (1) is a cast-in-situ plate, bolt holes are reserved on the lower flange of the steel beam at the hogging moment of the combined action beam, and the lower precast concrete plate, the triangular steel plate stopper and the lower flange of the steel beam are connected into a whole through bolts; the top of the upper flange of the steel beam is welded with a peg, and a concrete slab is poured; the triangular steel plate stopper is formed by welding two rectangular steel plates and three right-angle triangular steel plates with the same size, the width ratio of the two rectangular steel plates is 1:2, the length and the thickness are the same, the long sides of the two rectangular steel plates are overlapped and welded at right angles, the right-angle edges of the three right-angle triangular steel plates are arranged in a short direction, and the three right-angle triangular steel plates are respectively welded at the four equal-dividing points of the long sides of the two rectangular steel plates;
the height h of the triangular steel plate stopper is equal to the thickness of the lower precast concrete slab, the length L of the triangular steel plate stopper is equal to the width of the lower precast concrete slab, and the thickness t of the steel plate is equal to the thickness of the lower flange of the steel beam and is not less than 16mm.
The number of the first bolt sets (9) in the lower precast concrete slab (5) is 300mm according to the longitudinal spacing, and the transverse spacing is half of the width of the lower flange of the steel beam; the end of the lower precast concrete slab (5) is reserved with a distance of 30mm from the post, and after the connection of the lower precast concrete slab and the triangular steel plate stopper with the steel beam is completed, the gap is filled by the C60 micro-expansion grouting material.
The number of second bolt sets (7) required by the triangular steel plate inhibitor (6) is calculated according to the design bearing capacity of the precast concrete slab at the lower part, and the calculation formula of the number of bolts is as follows:wherein A is c : the contact area between the end part of the lower precast concrete slab and the pillar; f (f) c : a concrete compressive strength design value; />And a second bolt sleeve sets a single bolt shearing bearing capacity design value.
The replaceable partially assembled steel-concrete double-sided combined action beam is characterized in that bolts connecting the lower precast concrete slab and the steel beam can bear the dead weight of the precast concrete slab and prevent the vertical lifting of the concrete slab. The horizontal thrust is borne by the triangular steel plate stopper; the number of bolts connecting the triangular steel plate stopper and the steel beam is determined by the magnitude of horizontal thrust and the shearing bearing capacity of a single bolt.
The replaceable partially assembled steel-concrete double-sided combined action beam is characterized in that the upper concrete slab is a cast-in-situ reinforced concrete slab.
The steel-concrete double-sided combined action beam is characterized in that steel materials used for the triangular steel plate stopper are the same as steel beams.
The steel-concrete double-sided combined action beam is characterized in that the lower precast concrete slab at the hogging moment of the combined beam is positioned at the lower part of the lower flange of the steel beam.
The replaceable partially assembled steel-concrete double-sided combined action beam is characterized in that the steel beam in the combined beam is an I-shaped or H-shaped steel beam.
The replaceable partially assembled steel-concrete double-sided combined action beam is characterized in that the triangular steel plate stopper is designed according to the requirements of the invention so as to ensure that the rigidity of the stopper meets the requirements, reduce the deformation and be stable and reliable after being stressed.
The replaceable partially assembled steel-concrete double-sided combined action beam is characterized in that the strength grade of concrete used by the lower precast concrete slab is not lower than C30.
The replaceable partially assembled steel-concrete double-sided combined action beam is characterized in that the positions of reserved bolt holes on a steel beam bottom flange, a lower precast concrete slab and a triangular steel plate stopper meet the precision requirement specified by the invention.
The replaceable partially assembled steel-concrete double-sided combined action beam is characterized in that the end part of the lower precast concrete slab and the triangular steel plate stopper are tightly pressed. The triangular steel plate inhibitor has the functions of resisting the horizontal thrust of the lower precast concrete plate, reducing the interface slippage between the lower precast concrete plate and the steel beam, and improving the rigidity and the ultimate bearing capacity of the composite beam;
the replaceable partially assembled steel-concrete double-sided combined action beam is characterized in that a triangular steel plate stopper is arranged at the end part of a lower precast concrete plate, and the steel-concrete double-sided combined action beam is integrally manufactured and installed.
Description of the drawings:
FIG. 1 is a schematic view of a three-dimensional structure of a replaceable partially fabricated steel-concrete double-sided composite action beam according to the present invention;
FIG. 2 is a side view of the present invention;
FIG. 3 is a schematic view of a section 1-1 of a composite beam of the present invention;
FIG. 4 is a schematic view in section 2-2 of a composite beam of the present invention;
FIG. 5 is a schematic view of a section 3-3 of a composite beam of the present invention;
FIG. 6 is a view of a triangular steel plate stopper of the composite beam of the present invention;
FIG. 7 is a schematic view of the installation position of the triangular steel plate stopper and the lower precast concrete panel of the composite beam of the present invention;
FIG. 8 is a three-dimensional schematic view of a triangular steel plate stopper of the composite beam of the present invention;
FIG. 9 is a graph comparing load-deflection curves of a composite beam of the present invention with those of a conventional composite Liang Kuazhong;
in the figure, 1-upper concrete slab, 2-upper reinforcing steel bar, 3-stud, 4-steel beam, 5-lower precast concrete slab, 6-triangular steel plate stopper, 7-second bolt set, 8-lower reinforcing steel bar, 9-first bolt set, 201-upper concrete slab top transverse distribution reinforcing steel bar, 202-upper concrete slab bottom transverse distribution reinforcing steel bar, 203-upper concrete slab top longitudinal stress reinforcing steel bar, 204-upper concrete slab bottom longitudinal stress reinforcing steel bar, 801-lower precast concrete slab top transverse distribution reinforcing steel bar, 802-lower precast concrete slab bottom transverse distribution reinforcing steel bar, 803-lower precast concrete slab top longitudinal stress reinforcing steel bar, 804-lower precast concrete slab bottom longitudinal stress reinforcing steel bar, 701-second bolt set screw, 702-second bolt set mounting nut, 901-first bolt set screw, 902-first bolt set mounting nut.
The specific embodiment is as follows:
the invention is further described below with reference to the accompanying drawings.
The invention relates to a replaceable partially assembled steel-concrete double-sided combined action beam, wherein an upper concrete slab is a cast-in-situ concrete slab, and top transverse steel bars, top longitudinal steel bars, bottom transverse steel bars and bottom longitudinal steel bars are uniformly arranged in the upper concrete slab; the steel beam is an I-shaped or H-shaped steel beam; the column is an I-shaped, H-shaped and box-shaped section steel column; the peg is a common peg; the steel beam and the steel column are formed by hot rolling or welding, and the steel used is steel for building structures; the bolts comprise a first bolt sleeve group and a second bolt sleeve group, and comprise screw rods, nuts and nuts; the lower concrete slab is a precast concrete slab, wherein top transverse steel bars, top longitudinal steel bars, bottom transverse steel bars and bottom longitudinal steel bars which are uniformly arranged are arranged in the precast concrete slab, and corresponding bolt holes are reserved in the precast concrete slab;
the upper concrete slab of the combined beam is a cast-in-situ concrete slab;
the number of the upper pegs of the upper flange of the steel beam is designed and calculated according to the complete shearing connection; the size, spacing and arrangement of the studs should meet the requirements of the relevant specifications and standards of the composite beam.
The size, the strength grade, the installation position and the like of the lower precast concrete plate are all determined by design calculation according to the formula and the method provided by the invention;
the lower concrete slab is a precast slab, and the positions of the bolt holes on the precast slab are in one-to-one correspondence with the positions of the holes on the lower flange of the steel beam, so that the precision requirement specified by the invention is met.
The first bolt sleeve bolts used by the lower precast concrete slab are used for fixing the lower precast concrete slab and preventing vertical lifting, so that the number and arrangement mode of the bolts are considered, but the vertical lifting force and the gravity of the lower precast concrete slab are small, and the bolts can meet the requirement of bearing capacity by arranging the bolts according to constructional measures.
The size, load bearing capacity and number of second bolt sets used for the delta steel plate inhibitor should be determined by the horizontal thrust between the lower precast concrete panel and the lower flange of the steel girder.
The positions of the holes on the triangular steel plate stopper are in one-to-one correspondence with the positions of the holes on the steel beam, so that the precision requirement specified by the invention is met.
The installation, disassembly and replacement method of the invention is as follows:
firstly, reserving corresponding bolt holes on the lower flange of the steel beam at the hogging moment of the combined beam, integrally prefabricating a lower concrete plate and a triangular steel plate stopper, and reserving corresponding bolt holes at the same time; secondly, placing a lower precast concrete plate and a triangular steel plate stopper at the lower part of a lower flange of the steel beam, respectively connecting the lower precast concrete plate and the triangular steel plate stopper with the lower flange of the steel beam through a first bolt sleeve group and a second bolt sleeve group, and pouring a 30mm gap by using a C60 micro-expansion grouting material; and finally, constructing the upper concrete plate by adopting a traditional construction process.
Later, when the lower precast concrete slab is damaged or the bearing capacity of the combined beam needs to be improved, the combination Liang Xiezai is firstly supported, then the lower concrete slab of the steel beam is disassembled, and a new concrete slab is replaced; and finally, removing the support and recovering the stress of the combined beam.
Claims (10)
1. The replaceable partially assembled steel-concrete double-sided combined action beam is characterized by comprising an upper concrete slab (1), an upper steel bar (2), a steel beam (4), a bolt (3), a first bolt sleeve group (9), a second bolt sleeve group (7), a triangular steel plate stopper (6), a lower precast concrete slab (5) and a lower steel bar (8); the upper concrete plate (1) is a cast-in-situ plate, bolt holes are reserved on the lower flange of the steel beam, the lower precast concrete plate and the triangular steel plate stopper at the hogging moment of the double-sided combined acting beam respectively, and the lower precast concrete plate, the triangular steel plate stopper and the lower flange of the steel beam are connected into a whole through bolts; the top of the upper flange of the steel beam is welded with a peg and a concrete slab is poured; the triangular steel plate stopper is formed by welding two rectangular steel plates and three right-angle triangular steel plates with the same size, the width ratio of the two rectangular steel plates is 1:2, the length and the thickness dimension are the same, the long sides of the two rectangular steel plates are overlapped and welded at right angles, and the right-angle edges of the three right-angle triangular steel plates are arranged in a short direction and are welded at the four equal-dividing points of the long sides of the two rectangular steel plates respectively;
the height h of the triangular steel plate stopper is equal to the thickness of the lower precast concrete slab, the length L of the triangular steel plate stopper is equal to the width of the lower precast concrete slab, and the thickness t of the steel plate is equal to the thickness of the lower flange of the steel beam and is not less than 16mm.
2. A replaceable partially assembled steel-concrete double-sided composite action beam according to claim 1, characterized in that the number of first bolt sets (9) in the lower precast concrete panel (5) is arranged with a longitudinal spacing of 300mm and a transverse spacing of half the width of the lower flange of the steel beam; and a gap of 30mm is reserved between the end part of the lower precast concrete plate (5) and the post, and after the lower precast concrete plate and the triangular steel plate stopper are integrally connected with the steel beam, the gap is filled with C60 micro-expansion grouting material.
3. A replaceable partially assembled steel-concrete double-sided composite action beam according to claim 1, characterized in that the number of second bolt sets (7) required for the delta steel plate inhibitor (6) is calculated and determined according to the design bearing capacity of the lower precast concrete slab, and the bolt number calculation formula:wherein A is c : the contact area between the end part of the lower precast concrete slab and the pillar; f (f) c : a concrete compressive strength design value; />And a second bolt sleeve sets a single bolt shearing bearing capacity design value.
4. A replaceable partially fabricated steel-concrete double-sided composite action beam according to claim 1, wherein: the upper concrete slab (1) is a cast-in-situ reinforced concrete slab; the upper concrete slab is internally provided with upper concrete slab top transverse distribution steel bars (201), upper concrete slab bottom transverse distribution steel bars (202), upper concrete slab top longitudinal stress steel bars (203) and upper concrete slab bottom longitudinal stress steel bars (204); the lower precast concrete plate (5) is internally provided with lower precast concrete plate top transverse distribution steel bars (801), lower precast concrete plate bottom transverse distribution steel bars (802), lower precast concrete plate top longitudinal stress steel bars (803) and lower precast concrete plate bottom longitudinal stress steel bars (804).
5. A replaceable partially assembled steel-concrete double-sided composite action beam according to claim 1, characterized in that the lower precast concrete panel (5) is located at the hogging moment of the composite beam at the lower part of the lower flange of the steel beam (4).
6. A replaceable partially assembled steel-concrete double-sided composite action beam according to claim 1, characterized in that the steel beams (4) in the composite beam are i-shaped or H-shaped steel beams.
7. A replaceable partially assembled steel-concrete double-sided composite action beam according to claim 1, characterized in that the steel used for the delta steel plate inhibitor (6) is the same as the steel beam.
8. A replaceable partially assembled steel-concrete double-sided composite action beam according to claim 1, characterized in that the concrete strength grade used for the lower precast concrete panel (5) is not lower than C30.
9. The replaceable partially assembled steel-concrete double-sided composite action beam according to claim 1, is characterized in that the position accuracy of the reserved bolt holes of the lower flange of the steel beam and the triangular steel plate stopper (6) is satisfied with + -2 mm, and the position accuracy of the reserved bolt holes in the lower precast concrete slab (5) is satisfied with + -5 mm.
10. A method for using a replaceable partially assembled steel-concrete double-sided composite action beam according to any one of claims 1-9, characterized in that corresponding bolt holes are reserved on the lower flange of the steel beam at the hogging moment of the composite beam, and a lower concrete slab and a triangular steel plate stopper are integrally prefabricated, while corresponding bolt holes are reserved; secondly, placing a lower precast concrete plate and a triangular steel plate stopper at the lower part of a lower flange of the steel beam, respectively connecting the lower precast concrete plate and the triangular steel plate stopper with the lower flange of the steel beam through a first bolt sleeve group and a second bolt sleeve group, and pouring a 30mm gap by using a C60 micro-expansion grouting material; finally, constructing an upper concrete slab;
when the lower precast concrete slab is damaged or the bearing capacity of the combined beam needs to be improved in the later period, the support pair Liang Xiezai is firstly used, then the lower concrete slab of the steel beam is disassembled, and a new concrete slab is replaced; and finally, removing the support and recovering the stress of the combined beam.
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Families Citing this family (4)
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CN110284656A (en) * | 2019-08-05 | 2019-09-27 | 郑州大学 | A kind of full assembled steel concrete combination beam |
CN110528778B (en) * | 2019-09-18 | 2024-03-12 | 苏州科技大学 | Novel tensile shear steel-concrete composite beam structure and manufacturing process thereof |
CN110629655B (en) * | 2019-10-09 | 2021-08-17 | 广西大学 | Steel concrete composite beam adopting local replaceable plate of suspended formwork system |
CN112376798B (en) * | 2020-11-09 | 2023-07-28 | 广州大学 | Assembled steel-UHPC beam plate structure based on bolt connection and manufacturing method thereof |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101022853B1 (en) * | 2010-07-15 | 2011-03-17 | 혜동브릿지 주식회사 | Composite girder for constructing bridge |
CN103556780A (en) * | 2013-10-29 | 2014-02-05 | 刘阳 | Flange buckling-preventing section steel and concrete composite beam |
CN204570445U (en) * | 2015-03-17 | 2015-08-19 | 广西交通科学研究院 | Bottom flange arranges two combination continuous beams of concrete filled steel tube |
CN106759899A (en) * | 2017-02-17 | 2017-05-31 | 北京工业大学 | A kind of assembled honeycomb web beam column node connection device for recovering function |
CN107386438A (en) * | 2017-06-23 | 2017-11-24 | 东南大学 | Edge of a wing friction-type shape-memory alloy rod Self-resetting steel-frame beam side column node |
-
2018
- 2018-09-12 CN CN201811063626.1A patent/CN109469259B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101022853B1 (en) * | 2010-07-15 | 2011-03-17 | 혜동브릿지 주식회사 | Composite girder for constructing bridge |
CN103556780A (en) * | 2013-10-29 | 2014-02-05 | 刘阳 | Flange buckling-preventing section steel and concrete composite beam |
CN204570445U (en) * | 2015-03-17 | 2015-08-19 | 广西交通科学研究院 | Bottom flange arranges two combination continuous beams of concrete filled steel tube |
CN106759899A (en) * | 2017-02-17 | 2017-05-31 | 北京工业大学 | A kind of assembled honeycomb web beam column node connection device for recovering function |
CN107386438A (en) * | 2017-06-23 | 2017-11-24 | 东南大学 | Edge of a wing friction-type shape-memory alloy rod Self-resetting steel-frame beam side column node |
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