CN112922230A - Section steel partially-wrapped concrete composite beam and design and construction method thereof - Google Patents
Section steel partially-wrapped concrete composite beam and design and construction method thereof Download PDFInfo
- Publication number
- CN112922230A CN112922230A CN202110347336.5A CN202110347336A CN112922230A CN 112922230 A CN112922230 A CN 112922230A CN 202110347336 A CN202110347336 A CN 202110347336A CN 112922230 A CN112922230 A CN 112922230A
- Authority
- CN
- China
- Prior art keywords
- steel
- concrete
- stirrup
- rock wool
- fire
- 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.)
- Pending
Links
Images
Classifications
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Building Environments (AREA)
- Rod-Shaped Construction Members (AREA)
Abstract
The utility model provides a shaped steel part parcel concrete composite beam and design and construction method thereof, includes the concrete of H shaped steel roof beam and part parcel H shaped steel roof beam, and the H shaped steel roof beam includes the girder steel web and establishes perpendicularly at two girder steel edges of a wing on girder steel web both sides, still includes to establish girder steel web both sides, and be located the fire-resistant rock wool board between two girder steel edges of a wing, and the height of fire-resistant rock wool board is less than the distance between two girder steel edges of a wing, and the width of fire-resistant rock wool board is less than girder steel edge of a wing width and the half of girder steel web width difference. Through the reasonable arrangement of the part structures, the problems that the existing large span beam is heavy in mass and has initial deflection in the span are solved while the bearing capacity and rigidity of the composite beam are not excessively reduced, the construction cost is reduced, and the composite beam can be applied to high-rise large-span steel structure buildings.
Description
Technical Field
The invention belongs to the technical field of structural engineering, and particularly relates to a section steel partially-wrapped concrete composite beam and a design and construction method thereof.
Background
The steel-concrete combined structure is a new structure developed on the basis of steel structure and reinforced concrete structure, and is characterized by that it uses section steel or steel plate to weld steel section, and on the upper surface, periphery or interior the concrete and section steel are poured to form a whole body so as to form a structure system with common stress. The steel beam web plate is generally provided with welding steel bars, studs, section steel or drilling penetrating bars and other modes so as to ensure that the steel beam and the abdominal concrete can jointly participate in work as a whole and improve the fire resistance of the member, and simultaneously, the upper and lower flanges of the steel beam and the web plate and the concrete interact with each other to be restrained, so that the peeling and cracking of the concrete in the abdomen are also restrained.
The existing section steel partially-wrapped concrete composite structure is in a large-span super high-rise structure, has heavy mass under the condition of high beam section, and is not beneficial to the construction and installation of a super high-rise steel structure or a reinforced concrete composite structure; the concrete part is added with additional structure dead weight, which brings adverse effect on horizontal structure earthquake resistance; the initial deflection of the composite beam exists in the span of the large-span structure, so that potential safety hazards are brought to the structure. The steel part of the composite beam has high manufacturing cost for antiseptic treatment, and has the problem of long-term maintenance after being put into use.
Disclosure of Invention
Aiming at the problems, the invention aims to provide a section steel partially-wrapped concrete composite beam and a design and construction method thereof, which solve the problems of heavy mass and initial deflection in the span of the existing large-span beam and reduce the construction cost by reasonably arranging the component structure without reducing the bearing capacity and the rigidity of the composite beam too much, and can be applied to high-rise large-span steel structure buildings.
In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:
the utility model provides a shaped steel part parcel concrete composite beam, includes the concrete of H shaped steel roof beam and part parcel H shaped steel roof beam, the H shaped steel roof beam includes the girder steel web and establishes two girder steel edges of a wing on girder steel web both sides perpendicularly, still including establishing girder steel web both sides, and be located two anti fire rock wool boards between the girder steel edge of a wing, the height of anti fire rock wool board is less than the distance between two girder steel edges of a wing, the width of anti fire rock wool board is less than girder steel edge of a wing width and the half of girder steel web width difference.
Further, still including establishing the steel reinforcement cage between two girder steel edges of a wing and fire-resistant rock wool inter-plate, the length and the H shaped steel roof beam length of steel reinforcement cage equal, and the steel reinforcement cage is wrapped up by the concrete.
Preferably, the reinforcement cage comprises a plurality of stirrup assemblies uniformly distributed along the longitudinal direction of the H-shaped steel beam;
the stirrup assembly comprises a first rectangular stirrup arranged on the inner side of a steel beam flange, the coplanarity of the first rectangular stirrup is perpendicular to the steel beam flange and the steel beam web, the height of the first rectangular stirrup is smaller than the distance between the inner side of the steel beam flange and the fire-resistant rock wool slab, and the width of the first rectangular stirrup is smaller than half of the difference between the width of the steel beam flange and the width of the steel beam web; the stirrup assembly further comprises a second rectangular stirrup which is arranged on the inner side of the flange of the other steel beam and is symmetrical to the first rectangular stirrup, and the structure of the second rectangular stirrup is consistent with that of the first rectangular stirrup;
the stirrup assembly also comprises a third stirrup which is connected between the first rectangular stirrup and the second rectangular stirrup and is vertical to the flange of the steel beam; the fire-resistant rock wool board is located the stirrup subassembly inboard, and leave the space of pouring concrete with the stirrup subassembly within a definite time, and the distance between fire-resistant rock wool board and first rectangle stirrup and second rectangle stirrup equals.
Preferably, the steel reinforcement cage still includes along H shaped steel roof beam vertical, and locate eight vertical muscle at first rectangle stirrup and second rectangle stirrup internal angle respectively, the length of indulging the muscle equals with H shaped steel roof beam length.
Further, still include along H shaped steel roof beam vertical even and transversely establish a plurality of shear bolt nails of two girder steel flanges inboards between two centreing, arbitrary shear bolt nail is established at two adjacent steel reinforcement cage midpoints.
Preferably, the diameter of the longitudinal bar is D, and the diameter of the stirrup component is D2D and D2All are 6mm-8 mm; the height of the stirrup component is hg1＝h-2tf-10mm, wherein H is the height of the H-beam, tfThe thickness of the steel beam flange is 10mm, and the reserved error is 10 mm;
the width of the first rectangular stirrup is
Wherein b is the width of the H-shaped steel beam, twThe thickness of the steel beam web is shown, c is the thickness of concrete outside the first rectangular stirrup, and c is 15-20mm, and 20mm is the thickness of concrete between the first rectangular stirrup and the steel beam web;
the height of the first rectangular stirrup is hg3＝h1-10mm≥6D+2d2Wherein h is1The distance between the inner side of the flange of the steel beam and the fire-resistant rock wool plate is 10mm, and the thickness of concrete between the first rectangular stirrup and the fire-resistant rock wool plate is 10 mm;
length h of shear studs＝h115mm, 15mm being the thickness of the concrete from the free end of the shear-resistant stud to the fire-resistant rock wool slab, the diameter of the shear-resistant stud being
The distance between the adjacent stirrup components and the distance between the adjacent shear studs are both 150mm-200 mm.
Preferably, the height-width ratio of the H-shaped steel beam is 1.5, and the thickness t of the flange of the steel beam isf8mm-10mm, the thickness t of the steel beam web platew10mm-12mm, the distance h between the inner side of the steel beam flange and the fire-resistant rock wool plate1Is the thickness t of the flange of the steel beam f10 times, the distance between the flanges of the two steel beams is more than 5 times of the distance h between the inner side of the flange of the steel beam and the fireproof rock wool plate1；
The height of the fire-resistant rock wool board is hk1＝h-2tf-2h1The width of the fire-resistant rock wool board is
The invention discloses a design method of a section steel part wrapped concrete composite beam, which comprises the following steps:
determining the beam height and the beam width of the H-shaped steel beam according to the total length of the combined beam;
determining the thicknesses of the steel beam flange and the steel beam web according to the beam height and the beam width;
and determining the height and the width of the fire-resistant rock wool board according to the height and the width of the beam and the thickness of the steel beam flange and the steel beam web.
The invention discloses a design method of a section steel part wrapped concrete composite beam, which comprises the following steps:
determining the beam height and the beam width of the H-shaped steel beam according to the total length of the combined beam;
determining the thicknesses of the steel beam flange and the steel beam web according to the beam height and the beam width;
determining the diameter and height of the stirrup assemblies and the distance between adjacent stirrup assemblies according to the height and width of the beam, the width and height of the beam, the thickness of the steel beam flange and the steel beam web and the height and width of the fire-resistant rock wool plate, determining the width and height of the first rectangular stirrup, determining the diameter and length of the longitudinal bar and determining the length and diameter of the shear-resistant stud;
determining the height and the width of the fire-resistant rock wool board according to the size of the stirrup assembly;
meanwhile, the mechanical property of the composite beam meets the following conditions:
fcwDesigned value (N/mm) for compression strength of concrete at abdomen of main steel part of beam2)；
x is the distance (mm) from the neutral axis of the combined section to the pressed edge of the concrete;
α1the concrete compression stress influence coefficient of the compression area is when the concrete strength grade does not exceed C5When the concrete strength grade is C80, the alpha is 0.94, and the alpha is determined by a linear interpolation method;
fydesigned value (N/mm) for tensile strength of steel bar2)；
fy' design value for compressive strength of reinforcing steel bar (N/mm)2)；
faDesigned value (N/mm) for tensile strength of beam main steel part2)；
fa' design value for compressive strength of girder main steel member (N/mm)2)；
AsIs the cross-sectional area (mm) of the tensioned steel bar2)；
As' is the cross-sectional area (mm) of the steel bar under pressure2)；
AcIs the whole cross-sectional area (mm) of the main steel part of the beam2)；
AacIs the section area (mm) of the compression zone of the beam main steel part2)；
asThe distance (mm) from the resultant point of the reinforcing steel bar in the tension area to the tension edge of the concrete;
a′sthe distance (mm) from the resultant point of the reinforcing steel bar in the compression area to the compression edge of the concrete;
Satarea moment (mm) of beam main steel member cross section to combined cross section plasticity neutralization shaft in tension area3)；
SacIs the area moment (mm) of the plastic neutralization shaft of the section of the compression zone beam main steel component to the combined section3)；
hwThe height (mm) of the web of the steel beam;
fvis the shear-resisting bearing capacity (N/mm) of steel2)；
And 3, adopting a converted section method for the local stability and the overall stability of the composite beam, wherein the converted section method is
Or
σcIs the strain of the concrete;
σsstrain of steel;
Ecis the modulus of elasticity (N/mm) of the concrete2)；
EsIs the modulus of elasticity (N/mm) of the steel material2)；
αEIs the modulus of elasticity E of the steel materialsModulus of elasticity E with concretecThe ratio of (A) to (B);
Acis the area (mm) of the concrete unit;
As' is the area (mm) of the concrete section converted into the equivalent steel section.
The invention discloses a construction method for a section steel part-wrapped concrete composite beam, which comprises the following steps:
and 2, pouring concrete between two steel beam flanges of the H-shaped steel beam.
Compared with the prior art, the invention has the advantages that:
(1) according to the section steel part-wrapped concrete composite beam and the design method thereof, through reasonable arrangement of components, the two fire-resistant rock wool boards are respectively arranged on two sides of the steel beam web and are positioned between two steel beam flanges, the beam is light in weight and occupies space, the use of concrete is reduced, the fire resistance is improved while the overall structure quality is reduced, the overall structure is arranged, the mass of the overall composite beam is reduced while the bearing capacity and the rigidity of the composite beam are not reduced too much, the initial deflection is reduced, the engineering cost is reduced, and the beam can be applied to high-rise large-span steel structure buildings.
(2) According to the section steel part-wrapped concrete composite beam and the design method thereof, through reasonable arrangement of the parts, the steel reinforcement cage is used for bearing the fire-resistant rock wool boards and limiting the fire-resistant rock wool boards, and meanwhile, the overall stability of concrete is improved, and the bearing capacity and the rigidity of the overall composite beam are improved; the structure setting of stirrup subassembly increases lateral rigidity, prevents the outer bucking in plane, increases concrete overall stability, has improved the common working ability of H shaped steel roof beam with the concrete.
(3) The section steel part-wrapped concrete composite beam and the design and construction method thereof have the advantages of reasonable design, capability of ensuring good bearing capacity of the structure, simplified construction, guaranteed construction quality, full complementation of the advantages of the concrete and the steel structure and convenience in popularization and use.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:
FIG. 1 is a schematic external view of a sectional steel partially-wrapped concrete composite beam according to the present invention;
FIG. 2 is a schematic view of the structure of FIG. 1;
FIG. 3 is an elevational cross-sectional view of FIG. 1;
FIG. 4 is a side sectional view of FIG. 1;
FIG. 5 is a dimensioning diagram of FIG. 4;
FIG. 6 is a stress cloud of an H-shaped steel beam in a composite beam according to an embodiment of the present invention;
FIG. 7 is a cloud view of concrete stress in a composite beam according to an embodiment of the present invention;
FIG. 8 is a force cloud of a reinforcement cage in a composite beam according to an embodiment of the present invention;
FIG. 9 is a load-deflection plot for a two point monotonic loading of the midspan of the composite beams of the present invention and the comparative steel beams;
the reference numerals in the figures denote:
1H-shaped steel beam; 1-1 steel beam flange; 1-2 steel beam webs; 2 shear resistant studs; 3, a reinforcement cage; 3-1, a stirrup assembly; 3-11 first rectangular stirrups; 3-12 second rectangular stirrups; 3-13 third stirrups; 3-2 longitudinal ribs; 4, fire-resistant rock wool boards; 5 concrete
Detailed Description
The present invention is further described in detail below with reference to the attached drawings, which are illustrative of the invention and not limiting, and the terminology herein is understood according to the conventional understanding of those skilled in the art unless otherwise specified.
In the description of the present invention, it should be construed that the terms "end", "length", "height", "width", "thickness", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present invention.
A section steel partially-wrapped concrete composite beam comprises an H-shaped steel beam 1 and concrete 5 partially wrapping the H-shaped steel beam 1, wherein the H-shaped steel beam 1 comprises a steel beam web 1-2, two steel beam flanges 1-1 vertically arranged on two sides of the steel beam web 1-2, and fire-resistant rock wool boards 4 arranged on two sides of the steel beam web 1-2 and positioned between the two steel beam flanges 1-1, the height of each fire-resistant rock wool board 4 is smaller than the distance between the two steel beam flanges 1-1, and the width of each fire-resistant rock wool board 4 is smaller than half of the difference between the width of the steel beam flange 1-1 and the width of the steel beam web 1-2;
the function is as follows: the H-shaped steel beam 1 and the concrete 5 partially wrapping the H-shaped steel beam 1 jointly form a steel-concrete combined beam to form a commonly stressed structural system; the two fire-resistant rock wool boards 4 are respectively arranged on two sides of the steel beam web plate 1-2 and are positioned between the two steel beam flanges 1-1, the weight is light, the space is occupied, the use of concrete 5 is reduced, the fire resistance is improved while the quality of the whole structure is reduced, the quality of the whole combination beam is reduced while the bearing capacity and the rigidity of the combination beam are not excessively reduced, the initial deflection is reduced, the construction cost is reduced, and the fire-resistant rock wool board can be applied to high-rise large-span steel structure buildings.
Wherein, the H-shaped steel beam 1 preferably adopts the steel type of Q345 and above, and is subjected to sand blasting treatment before construction; the concrete 5 is preferably high-strength concrete or high-strength grouting material C60 or C80; the fire-resistant rock wool boards 4 are of a moisture-proof type and have a hard outer shell.
The steel bar reinforcement cage is characterized by further comprising a steel bar cage 3 arranged between two steel beam flanges 1-1 and the fireproof rock wool board 4, wherein the length of the steel bar cage 3 is equal to that of the H-shaped steel beam 1, and the steel bar cage 3 is wrapped by concrete 5;
the function is as follows: the reinforcement cage 3 is used for bearing the fire-resistant rock wool boards 4 and limiting the fire-resistant rock wool boards 4, and meanwhile, the overall stability of concrete is improved, and the bearing capacity of the overall composite beam is improved; the reinforcement cage 3 is wrapped by the concrete 5 to protect the reinforcement cage 3, and meanwhile, the upper and lower steel beam flanges 1-1 are indirectly connected, so that the overall stability of the concrete is improved, and the overall bearing capacity and rigidity of the composite beam are improved.
Wherein, the steel reinforcement cage 3 is preferably HRB335 type smooth round steel bar, and is polished smoothly before construction.
Specifically, the reinforcement cage 3 comprises a plurality of stirrup assemblies 3-1 which are uniformly distributed along the longitudinal direction of the H-shaped steel beam 1; the stirrup component 3-1 comprises a first rectangular stirrup 3-11 arranged on the inner side of a steel beam flange 1-1, the coplane of the first rectangular stirrup 3-11 is perpendicular to the steel beam flange 1-1 and a steel beam web 1-2, the height of the first rectangular stirrup 3-11 is smaller than the distance between the inner side of the steel beam flange 1-1 and the fire-resistant rock wool board 4, and the width of the first rectangular stirrup 3-11 is smaller than half of the difference between the width of the steel beam flange 1-1 and the width of the steel beam web 1-2; the stirrup component 3-1 also comprises a second rectangular stirrup 3-12 which is arranged at the inner side of the other steel beam flange 1-1 and is symmetrical to the first rectangular stirrup 3-11, and the structure of the second rectangular stirrup 3-12 is consistent with that of the first rectangular stirrup 3-11; the stirrup component 3-1 also comprises a third stirrup 3-13 which is connected between the first rectangular stirrup 3-11 and the second rectangular stirrup 3-12 and is vertical to the steel beam flange 1-1; the fire-resistant rock wool board 4 is positioned on the inner side of the stirrup component 3-1, a space for pouring concrete is reserved between the fire-resistant rock wool board 4 and the stirrup component 3-1, and the distances between the fire-resistant rock wool board 4 and the first rectangular stirrup 3-11 and the second rectangular stirrup 3-12 are equal;
the function is as follows: the plurality of the stirrup assemblies 3-1 and the stirrup assemblies 3-1 are uniformly distributed along the longitudinal direction of the H-shaped steel beam 1, so that the lateral rigidity is increased while the fire-resistant rock wool boards 4 are limited, out-of-plane buckling is prevented, the overall stability of concrete is improved, and the common working capacity of the H-shaped steel beam 1 and the concrete 5 is improved.
Specifically, the reinforcement cage 3 further comprises eight longitudinal bars 3-2 which are arranged at inner corners of the first rectangular stirrups 3-11 and the second rectangular stirrups 3-12 in the longitudinal direction of the H-shaped steel beam 1, and the length of each longitudinal bar 3-2 is equal to that of the H-shaped steel beam 1;
the function is as follows: the longitudinal ribs 3-2 are used to withstand stress caused by temperature change and concrete shrinkage and to suppress the development of concrete cracks.
Specifically, the steel bar cage further comprises a plurality of shear-resistant studs 2 which are uniformly arranged in the longitudinal direction of the H-shaped steel beam 1 and transversely and centrally arranged on the inner sides of the flanges 1-1 of the two steel beams, and any shear-resistant stud 2 is arranged at the midpoint of two adjacent steel bar cages 3;
the function is as follows: the shear-resistant stud 2 increases the contact area between the structure and the concrete 5, reduces the slippage of the H-shaped steel beam 1 and the concrete 5 in the combined beam, improves the bearing capacity, and improves the common working capacity of the H-shaped steel beam 1 and the concrete 5.
The shear-resistant stud 2 can be welded on the inner sides of the two steel beam flanges 1-1, and then the stirrup component 3-1 is spot-welded between the upper and lower steel beam flanges 1-1, or vice versa; the longitudinal bars 3-2 are connected and fixed to the stirrup component 3-1 later than the previous two processes, wherein the reinforcement cage 3 is bound and formed.
Wherein, the fire-resistant rock wool board 4 can be fixed on the right center of two sides of the steel beam web plate 1-2 by industrial bonding glue in advance before the formation of the steel reinforcement cage 3 and the welding of the shear-resistant stud 2; after the reinforcement cage 3 is bound and the shear-resistant studs 2 are welded, the reinforcement cage 3 can be inserted into two sides of the H-shaped steel beam, and then the steel beam is adjusted to the center of two sides of a steel beam web plate 1-2, and the ends of the steel beam web plate are fixed.
Specifically, the diameter of the longitudinal rib 3-2 is D, the diameter of the stirrup component 3-1 is D2, and both the diameter D and the diameter D2 are 6mm-8 mm; the height of the stirrup component 3-1 is hg1＝h-2tf10mm, wherein H is the height of the H-shaped steel beam 1, tfThe thickness of the steel beam flange is 1-1, and the reserved error is 10 mm; the first rectangular stirrups 3 to 11 have the width of
Wherein b is the width of the H-shaped steel beam 1, twThe thickness of a steel beam web plate 1-2 is shown, c is the thickness of concrete 5 on the outer side of the first rectangular stirrups 3-11, and c is 15-20mm, and 20mm is the thickness of the concrete 5 between the first rectangular stirrups 3-11 and the steel beam web plate 1-2; the height of the first rectangular stirrup 3-11 is hg3＝h1-10mm≥6D+2d2Wherein h is1The distance between the inner side of the steel beam flange 1-1 and the fire-resistant rock wool board 4 is 10mm, and the thickness of concrete between the first rectangular stirrup 3-11 and the fire-resistant rock wool board 4 is 10 mm; length h of shear stud 2s＝h115mm, the thickness of the concrete between the free end of the shear-resistant stud 2 and the fire-resistant rock wool board 4 is 15mm, and the diameter of the shear-resistant stud 2 is
The distance between the adjacent stirrup components 3-1 and the distance between the adjacent shear studs 2 are both 150mm-200 mm.
Wherein, the reinforcement cage 3 is formed by binding a stirrup component 3-1 and a longitudinal bar 3-2 by steel wires.
Wherein the height h of the first rectangular stirrup is 3-11g3≥6D+2d2To ensure that it is greater than the minimum mating band ratio.
Specifically, the height-to-width ratio of the H-shaped steel beam 1 is 1.5, and the thickness t of the steel beam flange 1-1f8mm-10mm, thickness t of steel beam web 1-2w10mm-12mm, the distance h between the inner side of the steel beam flange 1-1 and the fire-resistant rock wool board 41Is a steel beam flange with the thickness t of 1-1f10 times, the distance between the two steel beam flanges 1-1 is more than 5 times of the distance h between the inner side of the steel beam flange 1-1 and the fire-resistant rock wool board 41(ii) a The height of the fire-resistant rock wool board 4 is hk1＝h-2tf-2h1The width of the fire-resistant rock wool board 4 is
The invention discloses a design method of a section steel part wrapped concrete composite beam, which comprises the following steps:
determining the beam height and the beam width of the H-shaped steel beam 1 according to the total length of the combined beam;
determining the thicknesses of a steel beam flange 1-1 and a steel beam web plate 1-2 according to the beam height and the beam width;
according to the height and the width of a beam, the thickness of a steel beam flange 1-1 and a steel beam web plate 1-2 and the height and the width of a fire-resistant rock wool board 4, the diameter and the height of a stirrup component 3-1 and the distance between adjacent stirrup components 3-1 are determined, the width and the height of a first rectangular stirrup 3-11 are determined, the diameter and the length of a longitudinal rib 3-2 are determined, and the length and the diameter of a shear-resistant stud 2 are determined;
determining the height and the width of the fire-resistant rock wool board 4 according to the size of the stirrup component 3-1;
meanwhile, the mechanical property of the composite beam meets the following conditions:
the method comprises the following steps that 1, the design value Md of the positive bending moment of the composite beam is smaller than the design value MU of the bending resistance bearing capacity;
fcwThe design value of the compression strength N/mm of the concrete at the belly of the girder main steel part2；
x is the distance mm from the neutralization shaft of the combined section to the pressed edge of the concrete;
α1the influence coefficient of the concrete compressive stress of the compression area is determined according to a linear interpolation method, wherein alpha is 1.0 when the concrete strength grade does not exceed C50, and alpha is 0.94 when the concrete strength grade is C80;
fydesigned value N/mm for tensile strength of steel bar2；
fy' design value N/mm for compressive strength of reinforcing steel bar2；
faDesigned value N/mm for tensile strength of beam main steel part2；
fa' design value N/mm for compressive strength of main steel part of beam2；
AsIs the cross section area mm of the tensioned steel bar2；
As' is the cross-sectional area mm of the pressed reinforcing steel bar2；
AcIs the whole cross-sectional area mm of the beam main steel part2；
AacIs the cross section area mm of the compression zone of the beam main steel part2；
asThe distance between the resultant point of the steel bar in the tension area and the tension edge of the concrete is mm;
a′sthe stress point of the steel bar in the compression area to the concreteThe distance of the edges mm;
Satarea moment mm of beam main steel member cross section in tension area to combined cross section plasticity neutralization shaft3；
SacThe area moment mm of the plastic neutralization shaft of the section of the compression area beam main steel component to the combined section3；
hwThe height of a steel beam web is mm;
fvis the shear-resistant bearing capacity N/mm of steel2；
And 3, adopting a converted section method for the local stability and the overall stability of the composite beam, wherein the converted section method is
Or
σcIs the strain of the concrete;
σsstrain of steel;
Ecis the elastic modulus N/mm of concrete2；
EsIs the elastic modulus N/mm of steel2；
αEIs the modulus of elasticity E of the steel materialsModulus of elasticity E with concretecThe ratio of (A) to (B);
Acis the area mm of the concrete unit;
As' is the area mm of the concrete section converted into the equivalent steel section.
The invention discloses a construction method for a section steel part-wrapped concrete composite beam, which comprises the following steps:
and 2, pouring concrete 5 between two steel beam flanges 1-1 of the H-shaped steel beam 1.
Example 1
The present embodiment provides a section steel partially-wrapped concrete composite girder, as shown in fig. 1 to 5.
The composite girder of the present embodiment includes an H-shaped steel girder 1, shear studs 2, a reinforcement cage 3, fire-resistant rock wool panels 4, and concrete 5. The H-shaped steel beam 1 comprises a steel beam web plate 1-2 and two steel beam flanges 1-1 vertically arranged on two sides of the steel beam web plate 1-2, the fire-resistant rock wool boards 4 are arranged on two sides of the steel beam web plate 1-2 and located between the two steel beam flanges 1-1, the height of each fire-resistant rock wool board 4 is smaller than the distance between the two steel beam flanges 1-1, and the width of each fire-resistant rock wool board 4 is smaller than half of the difference between the width of the steel beam flange 1-1 and the width of the steel beam web plate 1-2. The reinforcement cage 3 is arranged between the two steel beam flanges 1-1 and the fire-resistant rock wool board 4, the length of the reinforcement cage 3 is equal to that of the H-shaped steel beam 1, and the reinforcement cage 3 is wrapped by concrete 5; the reinforcement cage 3 comprises a plurality of stirrup assemblies 3-1 which are uniformly distributed along the longitudinal direction of the H-shaped steel beam 1, and each stirrup assembly 3-1 consists of a first rectangular stirrup 3-11, a second rectangular stirrup 3-12 and a third stirrup 3-13; the reinforcement cage 3 further comprises eight longitudinal bars 3-2 which are arranged at inner corners of the first rectangular stirrups 3-11 and the second rectangular stirrups 3-12 in the longitudinal direction of the H-shaped steel beam 1. The shear-resistant studs 2 are uniformly arranged on the inner sides of the two steel beam flanges 1-1 in the longitudinal direction of the H-shaped steel beam 1 and transversely and centrally, and any shear-resistant stud 2 is arranged at the midpoint of the two adjacent steel reinforcement cages 3.
The total length of the specific exemplary composite beam is 3300mm, and the section dimension h x b x t is determined according to the total beam length and the design principle of a steel structurew×tf400mm × 250mm × 10mm × 8 mm; selected diameter d of shear-resistant stud 2114mm, length hs60mm, total 46; the stirrup component 3-1 is made of HRB335 type steel with the diameter d of the stirrup2＝6mm，hg1＝384mm,hg2＝85mm,hg360mm, 44 in total; the longitudinal bars 3-2 are made of HRB335 type steel, the diameter D of the longitudinal bars 4 is 8mm, the length is 3300mm, and the total number of the longitudinal bars is 8. The fire-resistant rock wool board 4 has three dimensions l × b × h equal to 3300mm × 90mm × 244mm, and the fire-resistant rock wool board 4 is a non-bearing structure of a stressed member in the structure, so that the fire-resistant rock wool board may not be arranged in stress analysis simulation, and only occupies space. Concrete 5-selected C60 type high-strength concreteAnd (7) solidifying the concrete.
The combined beam of the embodiment is a simply supported beam, and stress surfaces at two ends are hinged; the composite beam of the embodiment adopts a two-point unidirectional symmetrical loading mechanism, the shear-span ratio lambda is 3.12, and the distance between the two loads is 500 mm.
Meanwhile, the mechanical property of the composite beam meets the following conditions, and the composite beam can be obtained by calculation:
Under the condition 3, the local stability and the overall stability of the composite beam adopt a conversion section method;
namely, the flange thickness is changed to 12.3+ 8-20.3 mm after conversion, the section size is changed to 400mm multiplied by 250mm multiplied by 8mm multiplied by 20.3mm, and the section size meets the requirement by consulting the technical regulation of partially filled steel-concrete structure.
Fig. 6-8 are force cloud charts of the composite beam, the concrete and the reinforcement cage in example 1, respectively, and show that the composite beam, the concrete and the reinforcement cage are well stressed.
Comparative example
Selecting the length of 3300mm and the cross-sectional dimension h x b x tw×tfThe test pieces of the comparative H-beam steel of 400mm × 250mm × 10mm × 8mm were the same as the composite beam of example 1 in terms of the constraints, boundary conditions, and loading mechanism.
As shown in fig. 9, which is a load-displacement curve diagram of the composite beam of example 1 and the test piece of the comparative H-shaped steel beam, it can be seen that the flexural capacity of the composite beam of example 1 is increased by 16.67% compared to the test piece of the comparative H-shaped steel beam, and good plasticity and ductility are exhibited.
Example 2
The embodiment provides a design method of a section steel part-wrapped concrete composite beam in embodiment 1, which specifically includes:
determining the beam height and the beam width of the H-shaped steel beam 1 according to the total length of the combined beam;
determining the thicknesses of a steel beam flange 1-1 and a steel beam web plate 1-2 according to the beam height and the beam width;
according to the height and the width of a beam, the thickness of a steel beam flange 1-1 and a steel beam web plate 1-2 and the height and the width of a fire-resistant rock wool board 4, the diameter and the height of a stirrup component 3-1 and the distance between adjacent stirrup components 3-1 are determined, the width and the height of a first rectangular stirrup 3-11 are determined, the diameter and the length of a longitudinal rib 3-2 are determined, and the length and the diameter of a shear-resistant stud 2 are determined;
determining the height and the width of the fire-resistant rock wool board 4 according to the size of the stirrup component 3-1;
meanwhile, the mechanical property of the composite beam meets the following conditions:
fcwDesigned value (N/mm) for compression strength of concrete at abdomen of main steel part of beam2)；
x is the distance (mm) from the neutral axis of the combined section to the pressed edge of the concrete;
α1the concrete compression stress influence coefficient of the compression area is that when the concrete strength grade does not exceed CAt 50, alpha is 1.0, and when the concrete strength grade is C80, alpha is 0.94, and the alpha is determined by a linear interpolation method;
fydesigned value (N/mm) for tensile strength of steel bar2)；
fy' design value for compressive strength of reinforcing steel bar (N/mm)2)；
faDesigned value (N/mm) for tensile strength of beam main steel part2)；
fa' design value for compressive strength of girder main steel member (N/mm)2)；
AsIs the cross-sectional area (mm) of the tensioned steel bar2)；
As' is the cross-sectional area (mm) of the steel bar under pressure2)；
AcIs the whole cross-sectional area (mm) of the main steel part of the beam2)；
AacIs the section area (mm) of the compression zone of the beam main steel part2)；
asThe distance (mm) from the resultant point of the reinforcing steel bar in the tension area to the tension edge of the concrete;
a′sthe distance (mm) from the resultant point of the reinforcing steel bar in the compression area to the compression edge of the concrete;
Satarea moment (mm) of beam main steel member cross section to combined cross section plasticity neutralization shaft in tension area3)；
SacIs the area moment (mm) of the plastic neutralization shaft of the section of the compression zone beam main steel component to the combined section3)；
hwThe height (mm) of the web of the steel beam;
fvis the shear-resisting bearing capacity (N/mm) of steel2)；
And 3, adopting a converted section method for the local stability and the overall stability of the composite beam, wherein the converted section method is
Or
σcIs the strain of the concrete;
σsstrain of steel;
Ecis the modulus of elasticity (N/mm) of the concrete2)；
EsIs the modulus of elasticity (N/mm) of the steel material2)；
αEIs the modulus of elasticity E of the steel materialsModulus of elasticity E with concretecThe ratio of (A) to (B);
Acis the area (mm) of the concrete unit;
As' is the area (mm) of the concrete section converted into the equivalent steel section.
The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.
It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.
In addition, any combination of the various embodiments of the present disclosure can be made, and the same should be considered as the inventive content of the present disclosure, as long as the combination does not depart from the spirit of the present disclosure.
Claims (10)
1. The utility model provides a shaped steel part parcel concrete combination roof beam, includes concrete (5) of H shaped steel roof beam (1) and part parcel H shaped steel roof beam (1), H shaped steel roof beam (1) include girder steel web (1-2) and establish two girder steel edges of a wing (1-1) on girder steel web (1-2) both sides perpendicularly, its characterized in that still including establishing girder steel web (1-2) both sides, and be located two girder steel edges of a wing (1-1) between fire-resistant rock wool board (4), the height of fire-resistant rock wool board (4) is less than the distance between two girder steel edges of a wing (1-1), and the width of fire-resistant rock wool board (4) is less than girder steel edge of a wing (1-1) width and girder steel web (1-2) width difference half.
2. The section steel partially-wrapped concrete composite beam according to claim 1, further comprising a reinforcement cage (3) provided between two beam flanges (1-1) and the fire-resistant rock wool panel (4), wherein the length of the reinforcement cage (3) is equal to the length of the H-shaped beam (1), and the reinforcement cage (3) is wrapped by the concrete (5).
3. The section steel partially-wrapped concrete composite beam according to claim 2, wherein the reinforcement cage (3) comprises a plurality of stirrup members (3-1) uniformly distributed in the longitudinal direction of the H-shaped steel beam (1);
the stirrup component (3-1) comprises a first rectangular stirrup (3-11) arranged on the inner side of a steel beam flange (1-1), the coplane of the first rectangular stirrup (3-11) is perpendicular to the steel beam flange (1-1) and a steel beam web (1-2), the height of the first rectangular stirrup (3-11) is smaller than the distance between the inner side of the steel beam flange (1-1) and the fire-resistant rock wool board (4), and the width of the first rectangular stirrup (3-11) is smaller than half of the difference between the width of the steel beam flange (1-1) and the width of the steel beam web (1-2); the stirrup component (3-1) further comprises a second rectangular stirrup (3-12) which is arranged on the inner side of the other steel beam flange (1-1) and is symmetrical to the first rectangular stirrup (3-11), and the structure of the second rectangular stirrup (3-12) is consistent with that of the first rectangular stirrup (3-11); the hoop component (3-1) further comprises a third hoop (3-13) which is connected between the first rectangular hoop (3-11) and the second rectangular hoop (3-12) and is perpendicular to the steel beam flange (1-1);
the fireproof rock wool board (4) is located on the inner side of the stirrup component (3-1) and a space for pouring concrete is reserved between the fireproof rock wool board and the stirrup component (3-1), and the distance between the fireproof rock wool board (4) and the first rectangular stirrup (3-11) and the distance between the fireproof rock wool board and the second rectangular stirrup (3-12) are equal.
4. The section steel partially-wrapped concrete composite beam according to claim 3, wherein the reinforcement cage (3) further comprises eight longitudinal bars (3-2) arranged along the longitudinal direction of the H-shaped steel beam (1) and at the inner corners of the first rectangular stirrups (3-11) and the second rectangular stirrups (3-12), respectively, and the length of the longitudinal bars (3-2) is equal to the length of the H-shaped steel beam (1).
5. The section steel partially-wrapped concrete composite beam according to claim 4, further comprising a plurality of shear studs (2) uniformly arranged in the longitudinal direction of the H-shaped steel beam (1) and centrally arranged in the transverse direction inside the two steel beam flanges (1-1), wherein any one of the shear studs (2) is arranged at the midpoint of the adjacent two reinforcement cages (3).
6. Section steel partially-wrapped concrete composite beam according to claim 5, characterized in that the diameter of the longitudinal bar (3-2) is D and the diameter of the stirrup assembly (3-1) is D2D and D2All are 6mm-8 mm;
the height of the stirrup component (3-1) is hg1＝h-2tf-10mm, wherein H is the height of the H-beam (1), tfThe thickness of the steel beam flange (1-1) is 10mm, and a reserved error is obtained;
the width of the first rectangular stirrup (3-11) is
Wherein b is the width of the H-shaped steel beam (1), twThe thickness of a steel beam web plate (1-2), c is the thickness of concrete (5) on the outer side of the first rectangular stirrups (3-11), and c is 15-20mm, and 20mm is the thickness of the concrete (5) between the first rectangular stirrups (3-11) and the steel beam web plate (1-2);
the height of the first rectangular stirrup (3-11) is hg3＝h1-10mm≥6D+2d2Wherein h is1The distance between the inner side of the steel beam flange (1-1) and the fire-resistant rock wool board (4) is 10mm, and the thickness of concrete between the first rectangular stirrup (3-11) and the fire-resistant rock wool board (4) is 10 mm;
the length h of the shear-resistant stud (2)s＝h115mm, the thickness of the concrete between the free end of the shear-resistant stud (2) and the fire-resistant rock wool board (4) is 15mm, and the diameter of the shear-resistant stud (2) is
The distance between the adjacent stirrup components (3-1) and the distance between the adjacent shear-resistant studs (2) are both 150-200 mm.
7. Section steel partially-wrapped concrete composite beam according to any one of claims 1 to 6, wherein the H-shaped steel beam (1) has an aspect ratio of 1.5, and the thickness t of the beam flange (1-1)f8mm-10mm, the thickness t of the steel beam web (1-2)w10mm-12mm, the distance h between the inner side of the steel beam flange (1-1) and the fire-resistant rock wool board (4)1Is the thickness t of the steel beam flange (1-1)f10 times, the distance between the two steel beam flanges (1-1) is more than 5 times of the distance h between the inner side of the steel beam flange (1-1) and the fire-resistant rock wool board (4)1；
The height of the fire-resistant rock wool board (4) is hk1＝h-2tf-2h1The width of the fire-resistant rock wool board (4) is
8. The method for designing a section steel partially-wrapped concrete composite beam according to claim 1, comprising:
determining the beam height and the beam width of the H-shaped steel beam (1) according to the total length of the combined beam;
determining the thicknesses of a steel beam flange (1-1) and a steel beam web plate (1-2) according to the beam height and the beam width;
and determining the height and the width of the fire-resistant rock wool board (4) according to the height and the width of the beam and the thicknesses of the steel beam flange (1-1) and the steel beam web (1-2).
9. The method for designing a section steel partially-wrapped concrete composite beam according to claims 2 to 7, comprising:
determining the beam height and the beam width of the H-shaped steel beam (1) according to the total length of the combined beam;
determining the thicknesses of a steel beam flange (1-1) and a steel beam web plate (1-2) according to the beam height and the beam width;
according to the height and width of a beam, the thickness of a steel beam flange (1-1) and a steel beam web plate (1-2) and the height and width of a fire-resistant rock wool board (4), the diameter and height of a stirrup assembly (3-1) and the distance between adjacent stirrup assemblies (3-1) are determined, the width and height of a first rectangular stirrup (3-11) are determined, the diameter and length of a longitudinal bar (3-2) are determined, and the length and diameter of a shear-resistant stud (2) are determined;
determining the height and the width of the fire-resistant rock wool board (4) according to the size of the stirrup component (3-1);
meanwhile, the mechanical property of the composite beam meets the following conditions:
condition 1, design value of positive bending moment M of composite beamdLess than the design value M of bending resistance bearing capacityU；
fcwDesigned value (N/mm) for compression strength of concrete at abdomen of main steel part of beam2)；
x is the distance (mm) from the neutral axis of the combined section to the pressed edge of the concrete;
α1the influence coefficient of the concrete compressive stress of the compression area is determined according to a linear interpolation method, wherein alpha is 1.0 when the concrete strength grade does not exceed C50, and alpha is 0.94 when the concrete strength grade is C80;
fydesigned value (N/mm) for tensile strength of steel bar2)；
fy' design value for compressive strength of reinforcing steel bar (N/mm)2)；
faDesigned value (N/mm) for tensile strength of beam main steel part2)；
fa' design value for compressive strength of girder main steel member (N/mm)2)；
AsIs the cross-sectional area (mm) of the tensioned steel bar2)；
A′sIs the cross-sectional area (mm) of the steel bar under pressure2)；
AcIs the whole cross-sectional area (mm) of the main steel part of the beam2)；
AacIs the section area (mm) of the compression zone of the beam main steel part2)；
asThe distance (mm) from the resultant point of the reinforcing steel bar in the tension area to the tension edge of the concrete;
a′sthe distance (mm) from the resultant point of the reinforcing steel bar in the compression area to the compression edge of the concrete;
Satarea moment (mm) of beam main steel member cross section to combined cross section plasticity neutralization shaft in tension area3)；
SacIs the area moment (mm) of the plastic neutralization shaft of the section of the compression zone beam main steel component to the combined section3)；
Condition 2, the design value V of the shear resistance bearing capacity of the composite beam is less than or equal to hwtwfv；
hwThe height (mm) of the web of the steel beam;
fvis the shear-resisting bearing capacity (N/mm) of steel2)；
And 3, adopting a converted section method for the local stability and the overall stability of the composite beam, wherein the converted section method is
Or
σcIs the strain of the concrete;
σsstrain of steel;
Ecis the modulus of elasticity (N/mm) of the concrete2)；
EsIs the modulus of elasticity (N/mm) of the steel material2)；
αEIs the modulus of elasticity E of the steel materialsModulus of elasticity E with concretecThe ratio of (A) to (B);
Acis the area (mm) of the concrete unit;
As' is the area (mm) of the concrete section converted into the equivalent steel section.
10. A method of constructing a section steel partially-wrapped concrete composite beam according to claim 1, comprising:
step 1, fixedly arranging two fire-resistant rock wool boards (4) on two sides of a steel beam web plate (1-2) of an H-shaped steel beam (1) and between two steel beam flanges (1-1);
and 2, pouring concrete (5) between the two steel beam flanges (1-1) of the H-shaped steel beam (1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110347336.5A CN112922230A (en) | 2021-03-31 | 2021-03-31 | Section steel partially-wrapped concrete composite beam and design and construction method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110347336.5A CN112922230A (en) | 2021-03-31 | 2021-03-31 | Section steel partially-wrapped concrete composite beam and design and construction method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112922230A true CN112922230A (en) | 2021-06-08 |
Family
ID=76176771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110347336.5A Pending CN112922230A (en) | 2021-03-31 | 2021-03-31 | Section steel partially-wrapped concrete composite beam and design and construction method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112922230A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113738107A (en) * | 2021-07-15 | 2021-12-03 | 浙江绿筑集成科技有限公司 | Steel beam filling method based on inorganic material injection |
| CN114547729A (en) * | 2022-01-19 | 2022-05-27 | 江苏宿淮盐高速公路管理有限公司 | Quantitative identification method for bending rigidity of steel-concrete composite beam |
| CN114809443A (en) * | 2022-04-29 | 2022-07-29 | 东南大学 | Bearing-fireproof integrated prefabricated prestressed concrete combined secondary beam and manufacturing method thereof |
-
2021
- 2021-03-31 CN CN202110347336.5A patent/CN112922230A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113738107A (en) * | 2021-07-15 | 2021-12-03 | 浙江绿筑集成科技有限公司 | Steel beam filling method based on inorganic material injection |
| CN114547729A (en) * | 2022-01-19 | 2022-05-27 | 江苏宿淮盐高速公路管理有限公司 | Quantitative identification method for bending rigidity of steel-concrete composite beam |
| CN114809443A (en) * | 2022-04-29 | 2022-07-29 | 东南大学 | Bearing-fireproof integrated prefabricated prestressed concrete combined secondary beam and manufacturing method thereof |
| CN114809443B (en) * | 2022-04-29 | 2024-04-16 | 东南大学 | Bearing-fireproof integrated precast prestressed reinforced concrete combined secondary beam and manufacturing method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ricles et al. | Seismic performance of steel-encased composite columns | |
| US9765521B1 (en) | Precast reinforced concrete construction elements with pre-stressing connectors | |
| Tan | Strength enhancement of rectangular reinforced concrete columns using fiber-reinforced polymer | |
| KR101991638B1 (en) | Steel composite beam with steel materials on a pair of h-beams | |
| CN112922230A (en) | Section steel partially-wrapped concrete composite beam and design and construction method thereof | |
| French et al. | Connections between precast elements—Failure outside connection region | |
| CN114775408B (en) | Combined box girder external prestressed beam steering structure | |
| CN107524251B (en) | Prestress steel strip masonry faced wall | |
| CN112095920A (en) | Assembled section steel partially-wrapped concrete composite beam and design and construction method thereof | |
| Hayatdavoodi et al. | Web buckling and ultimate strength of composite plate girders subjected to shear and bending | |
| KR20220142848A (en) | Self-supporting ring girder | |
| CN215802674U (en) | Section steel part parcel concrete combination beam | |
| CN114108806A (en) | Prefabricated assembled steel pipe UHPC composite hollow column-steel beam combined frame | |
| JP2558100B2 (en) | Hybrid type fiber reinforced lightweight concrete structure | |
| CN110185145B (en) | Steel-concrete one-way combined beam column joint | |
| CN217680009U (en) | Truss web steel-concrete combined flange beam with self-fireproof and self-corrosion-resistant functions | |
| CN217680010U (en) | High-bearing-capacity steel-concrete combined flange beam with self-fireproof and self-corrosion-resistant functions | |
| CN215405531U (en) | T-shaped beam for check brake and working bridge | |
| CN218643163U (en) | Steel-concrete joint section connecting structure adopting injection type and anchor pull plate type steel truss combined bridge | |
| Holschemacher | Recent developments in timber-concrete composite construction | |
| CN214090532U (en) | Precast concrete ribbed bottom plate | |
| CN219622107U (en) | Assembled cladding steel concrete composite structure | |
| CN218843486U (en) | Quick-connection type variable-rigidity prefabricated floor slab and system thereof | |
| CN220550677U (en) | Profile steel concrete composite structure | |
| CN216893067U (en) | Assembled composite floor system |
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 |