Prefabricated assembly steel concrete rectangular combination column and construction method

Abstract

The invention discloses a prefabricated assembly steel concrete rectangular combination column and a construction method, and belongs to the technical field of building structures. According to the technical scheme, an ultra-high performance concrete shell, a stainless steel pipe, a PBL plate, a reinforcement cage, profile steel and common concrete are included. The stainless steel-UHPC formwork steel reinforced concrete rectangular combination column is formed through the components. The formwork part is prefabricated in a factory and has the advantages of being high in strength, excellent in crack resistance, fire resistance and corrosion resistance and the like, and on the construction site, the profile steel is fixed firstly, then the profile steel is sleeved with the formwork part, and finally common concrete is poured to complete installation of the combination column. The bearing capacity, the anti-seismic property and the ductility of the column can be remarkably improved through the formwork, later-poured common concrete and beam and plate concrete can be poured at the same time, and the integrity of the structure is improved. The method has the advantages of convenience in construction, excellent performance, cost saving, environment friendliness and the like, and is suitable for the fields of high-rise and super high-rise buildings, bridges, offshore buildings, energy infrastructures and the like.

Description

Technical Field

[0001] The invention relates to the technical field of building structures, and in particular to a prefabricated steel-concrete rectangular composite column and a construction method. Background Art

[0002] Traditional steel UHPC columns and prefabricated structures still have some technical bottlenecks:

[0003] 1) Heavy deadweight, high hoisting and installation costs. Steel concrete columns usually have large cross-sectional dimensions and heavy deadweight, which requires high transportation and hoisting equipment, increasing construction costs.

[0004] 2) The formwork engineering costs are high. The formwork engineering costs are high. Traditional construction methods require on-site steel bar binding, formwork support and formwork removal. The formwork material costs are high, and the labor costs during production, assembly and reuse are also quite high. As a result, the formwork engineering costs account for more than half of the total construction cost. There are also significant differences in the quality of formwork construction at different construction sites, which affects the overall quality of the project.

[0005] 3) The connection quality is difficult to guarantee and the structural integrity is insufficient. When the fully prefabricated steel-concrete columns are spliced ​​and assembled, although the steel and steel bars in the columns can be effectively connected, the stress mechanism of the concrete connection interface is unclear, the connection quality is difficult to meet the requirements, and the structural integrity is difficult to guarantee.

[0006] 4) The brittleness of UHPC materials is prominent. Compared with traditional concrete, the most prominent problem of UHPC is its obvious brittle characteristics. The concrete protective layer of steel UHPC columns is prone to bursting at critical failure, and the bearing capacity of the components drops sharply. Its ductility needs to be further improved.

[0007] 5) Inadequate use of high-performance materials. In traditional steel tube concrete columns, ordinary carbon steel is widely used as the main load-bearing material. Although it has certain strength and good processing properties, it is easily corroded by various environmental factors during use, which brings many adverse effects. For example, in coastal areas or industrial environments, salt, acidic substances in the air and high humidity conditions will accelerate the corrosion process of ordinary carbon steel. Rust will cause the cross-sectional size of the steel to decrease and the strength to decrease, which will in turn affect the bearing capacity and stability of the entire structure and shorten the service life of the structure. In order to cope with these problems, stainless steel has become a more preferred material. Stainless steel has excellent corrosion resistance. At the same time, stainless steel also has high strength and good ductility, which can work better with concrete and improve the overall performance of the structure. However, the high cost of stainless steel limits its application in large-scale buildings. Compared with ordinary carbon steel, the price of stainless steel is usually several times higher, which makes the comprehensive use of stainless steel as a load-bearing material in construction projects significantly increase the project cost and have an adverse effect on the economic efficiency of the project. At the same time, UHPC has obvious advantages in reducing the cross-sectional size of components and improving structural performance due to its ultra-high mechanical properties and durability, but its brittle characteristics and material cost also limit its promotion.

[0008] Therefore, a new composite column design is needed that can overcome the above technical defects while improving construction efficiency and reducing construction costs. Summary of the invention

[0009] In order to solve the above problems, the present invention proposes a prefabricated steel-concrete rectangular composite column and construction method, which combines ultra-high performance concrete, stainless steel pipes, PBL plates and steel cages to form a new type of composite column structure. Compared with the prior art, the present invention realizes full utilization and optimized combination of material properties in structural design, so that the column has higher bearing capacity, seismic resistance and durability; in terms of construction technology, the prefabricated formwork parts in the factory reduce the on-site construction process and time, improve construction efficiency and quality, and reduce construction costs.

[0010] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0011] A prefabricated steel-concrete rectangular composite column, comprising a high-performance formwork, wherein the high-performance formwork comprises an outer shell, a stainless steel pipe wrapped outside the outer shell, a plurality of PBL plates arranged in the stainless steel pipe, and a steel cage arranged in the outer shell;

[0012] Also included is a steel section disposed within a high performance formwork;

[0013] The shell is made of UHPC ultra-high performance concrete; as an ultra-high performance material, UHPC's ultra-high mechanical properties and durability can fully exert the material performance, thereby having certain advantages in reducing the cross-sectional size of the component, reducing the dead weight of the structure, and improving the structural stress performance.

[0014] Pour C50 grade ordinary concrete between the high-performance formwork and the steel section.

[0015] The cross-sectional shape of the high-performance mold shell is rectangular, and the cylindrical outer surface and inner surface are both flat.

[0016] The outer surface of the shell is wrapped with a thin-walled stainless steel tube, which has excellent corrosion resistance and can effectively prevent external environmental factors such as moisture, salt spray, chemicals, etc. from damaging the internal beam body, which is particularly important in buildings in coastal areas or industrial environments. For steel-concrete beams, the external stainless steel coating can act as a barrier to prevent moisture and oxygen from penetrating into the concrete, thereby delaying the corrosion process of the steel bars;

[0017] A plurality of evenly distributed PBL plates are welded on the inner wall of the stainless steel tube. On the one hand, the PBL plates can delay the buckling of the stainless steel tube, and on the other hand, improve the interface connection performance between the stainless steel tube and the UHPC material, thereby improving the overall performance of the structure.

[0018] The steel cage is composed of longitudinal steel bars and annular stirrups or spiral stirrups. It is arranged inside the ultra-high performance concrete shell. The stirrups are preferably continuous spiral composite stirrups, preferably continuous spiral composite high-strength stirrups with smaller stirrup spacing, so as to improve the lateral restraint effect of the prefabricated formwork on the internal post-cast concrete, improve the deformation and ductility of the composite column, ensure that the composite column has good seismic performance, and effectively prevent the external high performance or ultra-high performance concrete from bursting under fire, thereby improving the fire resistance of the composite column.

[0019] At the construction site, the steel section is first fixed, then the formwork is partially inserted into the steel section, and finally ordinary concrete is poured to ensure that the ordinary concrete is evenly filled to avoid voids or unevenness, ensure the density and integrity of the structure, and finally form a complete stainless steel-UHPC formwork steel-concrete rectangular composite column.

[0020] The construction method of the prefabricated steel-concrete rectangular composite column comprises the following steps:

[0021] S1: Material preparation, the specific steps are as follows:

[0022] 1) Select UHPC materials that meet the standards, whose main components include cement, fine aggregate, coarse aggregate, steel fiber, water reducer, etc. The specific mix ratio is: cement: fine aggregate: coarse aggregate: steel fiber: water reducer = 1: 2.5: 1.5: 0.03: 0.01 (mass ratio). The length of the steel fiber is 12mm, the diameter is 0.2mm, the tensile strength is ≥ 1500MPa, and the elastic modulus is ≥ 200GPa. The water reducer is a high-efficiency water reducer with a water reduction rate of ≥ 25%.

[0023] 2) 304 stainless steel is used, which has good corrosion resistance and strength. The thickness of the stainless steel pipe is 5mm, and the outer diameter is determined according to the design requirements;

[0024] 3) The PBL plate is made of high-strength steel plate with a thickness of 3mm. The surface is processed into a round hole or a long hole groove shape. The round hole diameter is 20mm, the long hole size is 20mm×50mm, and the hole spacing is 50mm. The tensile strength of the PBL plate is ≥500MPa, and the yield strength is ≥300MPa;

[0025] 4) The longitudinal reinforcement is HRB400 grade steel bar with a diameter of 12mm, a yield strength of ≥400MPa, and a tensile strength of ≥540MPa. The circular stirrups or spiral stirrups are also HRB400 grade steel bars with a diameter of 6mm and a stirrup spacing of 100mm. The size of the steel cage is determined according to the design requirements of the composite column to ensure that it can be completely wrapped in the ultra-high performance concrete shell;

[0026] 5) Select Q345B grade steel, which has good strength and rigidity. The specifications of the steel are determined according to the design bearing capacity and cross-sectional dimensions of the composite column;

[0027] 6) Use C50 grade ordinary concrete, whose main components include cement, fine aggregate, coarse aggregate, water, etc. The specific mix ratio is: cement: fine aggregate: coarse aggregate: water = 1:2.5:3.5:0.5 (mass ratio). Cement is silicate cement with a strength grade of 42.5. Fine aggregate is river sand with a fineness modulus of 2.5. Coarse aggregate is crushed stone with a particle size of 5mm-25mm.

[0028] S2: Prefabricated high-performance formwork is prepared in the factory. The specific steps are as follows:

[0029] 1) Cut the 304 stainless steel plate into an L shape according to the design size. Arrange the processed PBL plates evenly along the length direction of the L-shaped stainless steel, with the long side of the PBL plate parallel to the long side of the L-shaped stainless steel, and the short side perpendicular to the short side of the L-shaped stainless steel. The spacing between adjacent PBL plates is 1 / 3 of the length and width along the section. Use welding equipment to weld the PBL plate into the L-shaped stainless steel, with the weld length being twice the width of the PBL plate and the weld height being 3 mm;

[0030] 2) Splice two L-shaped stainless steels welded with PBL plates together to form a complete stainless steel pipe structure. When splicing, align the long sides of the two L-shaped stainless steels and fit the short sides together. Use welding equipment to weld the short sides of the two L-shaped stainless steels together. The length of the weld is twice the length of the short side and the weld height is 3mm. Ensure that the welding is firm and there are no defects such as pores and slag inclusions in the weld.

[0031] 3) According to the design requirements, HRB400 grade steel bars are cut into the required length and made into longitudinal steel bars and annular stirrups or spiral stirrups. The length of the longitudinal steel bars is the height of the composite column, and the length of the annular stirrups or spiral stirrups is the height of the composite column minus the thickness of the protective layer at both ends.

[0032] Tie the longitudinal reinforcement and the circular or spiral stirrups together to form a reinforcement cage. When tying, use iron wire to fix the stirrups to the longitudinal reinforcement, with a spacing of 100mm between the tying points to ensure that the shape of the reinforcement cage is regular and the size is accurate.

[0033] 4) Place the prepared steel cage into the stainless steel pipe, with the center of the steel cage coinciding with the center of the stainless steel pipe, and the two ends of the steel cage flush with the two ends of the stainless steel pipe. In the internal cavity of the stainless steel pipe, select a suitable inner mold according to the design requirements, which can be an inflatable rubber inner mold or a corrugated steel plate inner mold. The inflatable rubber inner mold is easy to disassemble and reuse, and is suitable for small-scale production; the corrugated steel plate inner mold is disposable, which can strengthen the interaction between the inner and outer concrete interfaces and is suitable for large-scale production. Fix the inner mold inside the stainless steel pipe to ensure that the inner mold fits tightly against the inner wall of the stainless steel pipe. Then, inject the prepared UHPC material into the stainless steel pipe through the concrete pouring equipment. The pouring should be continuous and uniform to avoid bubbles and voids. After the pouring is completed, perform appropriate vibration to make the concrete dense. After the UHPC solidifies and hardens, remove the inner mold to form the shell part of the prefabricated stainless steel-UHPC shell steel concrete rectangular composite column;

[0034] S3: Cast-in-place prefabricated steel-concrete rectangular composite columns. The specific steps are as follows:

[0035] 1) At the construction site, according to the design drawings and construction plan, fix the Q345B grade steel in the predetermined position. When fixing, you can use embedded parts or support frames to fix the steel on the foundation or existing structure to ensure the stability of the steel and prevent displacement or tilt during construction. The fixed position of the steel should meet the design requirements, and the deviation range should be controlled within ±5mm.

[0036] 2) Accurately fit the prefabricated formwork parts in the factory onto the outside of the profiled steel. The gap between the formwork and the profiled steel should meet the design requirements. During fitting, ensure that the center of the formwork coincides with the center of the profiled steel, and the two ends of the formwork are flush with the two ends of the profiled steel. Lifting equipment can be used to hoist the formwork to the construction site, and appropriate adjustment and positioning should be carried out during the fitting process.

[0037] 3) Pour C50 ordinary concrete between the formwork and the profiled steel. During pouring, it should be continuous and uniform to avoid generating bubbles and voids. Concrete pouring equipment can be used to inject the concrete into the gap between the formwork and the profiled steel, and the pouring height should be the same as the height of the formwork. After pouring, carry out appropriate vibration to make the concrete dense. After the concrete sets and hardens, carry out curing. The curing time is generally 28 days. During this period, keep the concrete surface moist to prevent cracks caused by dry shrinkage.

[0038] 4) During and after the construction process, strict quality inspection and acceptance should be carried out. The inspection contents include: the fixed position and stability of the profiled steel, the fitting position and gap of the formwork, the pouring quality and density of the concrete, the appearance and dimensions of the composite column, etc. The acceptance standards should comply with relevant codes and design requirements to ensure that the quality and performance of the composite column reach the expected goals.

[0039] It also includes auxiliary brackets for hoisting and installation;

[0040] The auxiliary bracket includes two bottom plates and two U-shaped clamps arranged in butt joint. Connecting ear plates are arranged on both sides of each U-shaped clamp, and the two U-shaped clamps are fixedly connected to the outer wall of the stainless steel pipe through bolts;

[0041] A vertical electric push rod is arranged at one end of the bottom plate close to the U-shaped clamp;

[0042] Connection seats are arranged at one end of the bottom plate far from the U-shaped clamp and on the outer wall of the U-shaped clamp, and a telescopic rod is arranged between the two connection seats.

[0043] The fixed end of the vertical electric push rod is fixedly arranged on the upper surface of the bottom plate, and the telescopic end of the vertical electric push rod is fixedly connected to the outer wall of the U-shaped clamp.

[0044] The telescopic rod includes an inner rod and an outer rod arranged in a sleeved manner. The two connection seats are respectively hinged to one end of an outer rod, and the inner rod is slidably arranged between the two outer rods;

[0045] Through holes are opened on the side walls of the inner rod and the outer rod, and the inner rod and the outer rod are fixedly connected by fixing the through holes with bolts.

[0046] It also includes a support adjustment mechanism that plays an auxiliary support and positioning role when the prefabricated assembled steel-concrete composite column is connected to the composite beam;

[0047] The support adjustment mechanism comprises two U-shaped clamps 2 that are butt-jointed, each of which is provided with connecting ear plates 2 on both sides, and the two U-shaped clamps 2 are fixedly connected to the outer wall of the stainless steel pipe by bolts;

[0048] A top plate is provided on the top of the second U-shaped clamp;

[0049] Both ends of each top plate are provided with electric push rods 2, the telescopic ends of the two electric push rods 2 are arranged opposite to each other, and push plates are fixedly provided at the ends of the telescopic ends of the two electric push rods 2, and the two push plates fix the combined beam from both sides;

[0050] The edge of the top plate is provided with scale lines for locating the position of the push plate.

[0051] The top plate is provided with a notch on one side close to the stainless steel pipe, and the notch corresponds to the groove of the second U-shaped clamp.

[0052] Through mechanical adjustment, the composite beams can be accurately aligned during installation and temporary support can be provided during construction to ensure structural stability and construction accuracy.

[0053] The organization mainly consists of the following parts:

[0054] U-shaped clamp 2: used to fix on the outer wall of the stainless steel pipe of the composite column to provide a stable support point.

[0055] Top plate: Installed on the top of the U-shaped clamp 2, serving as the mounting base for the electric push rod 2.

[0056] Electric push rod 2: installed at both ends of the top plate, its telescopic end contacts the combined beam through the push plate, and is used to adjust the position of the combined beam and provide support.

[0057] Push plate: fixed at the telescopic end of the second electric push rod, used to contact the composite beam and apply thrust.

[0058] Scale line: set on the edge of the top plate, used to accurately control the position of the push plate to ensure the positioning accuracy of the composite beam.

[0059] Notch: Opened on the side of the top plate close to the stainless steel pipe, corresponding to the groove of the second U-shaped clamp, used for installation and fixation.

[0060] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention is particularly suitable for load-bearing columns of high-rise and super-high-rise buildings, piers of bridges, supporting structures of offshore buildings, and towers in energy infrastructure, etc., and can effectively improve the bearing capacity and durability of these structures. Its advantages are mainly reflected in the following aspects:

[0061] (1) UHPC has extremely high compressive strength, which can reach more than 200 MPa, which is 3-4 times that of ordinary concrete. Its high strength comes from its low water-cement ratio, fine pore structure and the reinforcement of steel fibers. In composite columns, UHPC, as the core material, can effectively withstand axial pressure and lateral loads, significantly improving the bearing capacity of the column, making it suitable for structures with high bearing capacity requirements such as high-rise buildings and long-span bridges.

[0062] (2) The stainless steel tube itself has high strength and good ductility, with a yield strength of 200-300 MPa and a tensile strength of 500-700 MPa. In the composite column, the stainless steel tube is wrapped outside the UHPC shell, which plays a lateral restraining role on the UHPC, limiting its lateral expansion when under pressure, so that the strength of the UHPC can be fully utilized. At the same time, the stainless steel tube can also bear the load together with the UHPC, further improving the bearing capacity of the composite column, so that it can still maintain stable structural performance when bearing large loads.

[0063] (3) The PBL plates are evenly arranged and welded inside the stainless steel tube. When the composite column is subjected to earthquake or other forms of impact loads, the PBL plates can delay the buckling of the stainless steel tube and provide additional ductility. The circular hole or long hole groove design of the PBL plate enables it to produce local deformation and plastic hinges when subjected to force, absorbing and dissipating energy, thereby improving the seismic performance of the composite column, enabling it to better resist destruction in an earthquake and reduce structural damage.

[0064] (4) The steel cage is composed of longitudinal steel bars and annular or spiral stirrups and is arranged inside the UHPC shell. Under earthquake action, the steel cage can work together with the UHPC to provide good tensile and shear resistance. The continuous spiral composite design of the stirrups enhances the lateral constraint of the precast formwork on the internal post-cast concrete, improves the deformation capacity and ductility of the composite column, and ensures that the column will not suffer brittle failure during an earthquake, but absorbs energy through plastic deformation, thereby improving the seismic performance and safety of the structure.

[0065] (5) Stainless steel pipes have excellent corrosion resistance and can effectively resist erosion from environmental factors such as acid rain, salt spray, and chemicals. In buildings in coastal areas or industrial environments, stainless steel pipes serve as an external protective layer to prevent moisture and oxygen from penetrating into the concrete, thereby delaying the corrosion process of the steel bars and extending the service life of the structure. At the same time, stainless steel pipes can also protect UHPC from erosion by the external environment, maintaining its high strength and durability.

[0066] (6) The formwork part includes UHPC shell, stainless steel pipe, PBL plate and steel cage, which are prefabricated in the factory. Factory prefabrication can realize the standardization and automation of the production process, improve production efficiency and product quality. After the prefabricated formwork part is transported to the construction site, only simple installation and on-site pouring of ordinary concrete are required to complete the construction of the composite column, which reduces the on-site construction process and time, reduces the construction difficulty and labor intensity, and improves the construction efficiency.

[0067] (7) Traditional construction methods require a large amount of formwork materials, and the purchase, rental, transportation, installation and removal of the formwork all require a lot of costs. However, the composite column of the present invention has the formwork function included in the formwork part when it is prefabricated in the factory, and no additional formwork is required for on-site construction, which greatly reduces the formwork cost and construction cost. Since the composite column has excellent durability and corrosion resistance, it has a long service life and requires less maintenance and repair during use. Compared with traditional reinforced concrete columns, it can save a lot of maintenance costs and reduce the full life cycle cost of the building.

[0068] By combining UHPC and stainless steel, the column has high bearing capacity and crack resistance, and can maintain long-term durability in harsh environments. In addition, the prefabricated construction method improves construction efficiency and reduces on-site construction time and errors.

[0069] (8) The support adjustment mechanism can accurately adjust the position of the composite beam through the telescopic function of the electric push rod to ensure the connection accuracy between it and the composite column; the design of the scale line further improves the accuracy of positioning; the traditional installation method relies on manual adjustment, and the accuracy is difficult to guarantee, while this mechanism significantly improves the installation accuracy through mechanical adjustment;

[0070] During the installation of the composite beam, the support force provided by the electric push rod can effectively prevent the composite beam from being displaced or overturned due to its own weight or external force, ensuring the stability of the construction process; this mechanism provides temporary support for the composite beam, avoiding structural deformation or damage caused by improper installation;

[0071] The mechanical adjustment method reduces the tedious operation of manual adjustment, reduces labor intensity, improves construction efficiency, and speeds up construction progress;

[0072] The mechanism can adapt to combined beams of different sizes and weights through the telescopic range of the electric push rod and the adjustment function of the scale line, and has a wide range of applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0074] Figure 1 It is an overall schematic diagram of the prefabricated and assembled steel-concrete rectangular composite column according to an embodiment of the present invention.

[0075] Figure 2 It is a schematic diagram of the cross-sectional structure of the prefabricated steel-concrete rectangular composite column according to an embodiment of the present invention.

[0076] Figure 3 for Figure 2 Schematic diagram of the AA section along the central axis.

[0077] Figure 4 for Figure 2 Schematic diagram of the BB section along the central axis.

[0078] Figure 5 for Figure 2 Schematic diagram of the CC section along the central axis.

[0079] Figure 6 It is an overall schematic diagram of a complete steel-concrete rectangular composite column according to an embodiment of the present invention.

[0080] Figure 7 It is a schematic diagram of the cross-sectional structure of a complete steel-concrete rectangular composite column according to an embodiment of the present invention.

[0081] Figure 8 Schematic diagram of the structure of the auxiliary bracket according to an embodiment of the present invention.

[0082] Fig. 9 It is a structural schematic diagram of a support and adjustment mechanism according to an embodiment of the present invention.

[0083] Fig.10 It is a schematic structural diagram of the second U-shaped clamp according to an embodiment of the present invention.

[0084] The reference numerals are: 1. shell; 2. stainless steel pipe; 3. PBL plate; 4. steel cage; 5. steel; 6. ordinary concrete;

[0085] 11. U-shaped clamp; 13. Bottom plate; 12. Connecting ear plate; 14. Vertical electric push rod; 15. Connecting seat; 16. Telescopic rod;

[0086] 21. Two U-shaped clamps; 22. Two connecting ear plates; 23. Top plate; 24. Notch; 25. Two electric push rods; 26. Push plate; 27. Scale line. DETAILED DESCRIPTION

[0087] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0088] Example 1

[0089] See also Figures 1 to 7 , this embodiment provides a prefabricated assembled steel-concrete rectangular composite column and a construction method.

[0090] A prefabricated steel-concrete rectangular composite column, comprising a high-performance formwork, the high-performance formwork comprising an outer shell 1, a stainless steel pipe 2 wrapped outside the outer shell 1, a plurality of PBL plates 3 arranged in the stainless steel pipe 2, and a steel cage 4 arranged in the outer shell 1;

[0091] Also includes a steel section 5 disposed in the high performance formwork;

[0092] Shell 1 is made of UHPC ultra-high performance concrete;

[0093] C50 grade ordinary concrete 6 is poured between the high performance formwork and the steel section 5.

[0094] The cross-sectional shape of the high-performance mold shell is a rectangle, and both the outer surface and the inner surface of the rectangle are flat.

[0095] The outer surface of the housing 1 is wrapped with a thin-walled stainless steel tube 2 , and a plurality of evenly distributed PBL plates 3 are welded on the inner wall of the stainless steel tube 2 .

[0096] The reinforcement cage 4 is composed of longitudinal reinforcement and annular stirrups or spiral stirrups.

[0097] A construction method based on a prefabricated steel-concrete rectangular composite column includes the following steps:

[0098] S1: Prepare prefabricated high-performance formwork in the factory. The specific steps are as follows:

[0099] 1) According to the design size, two L-shaped stainless steels are selected, and the PBL plates 3 are evenly arranged along the length direction of the L-shaped stainless steels and welded inside the L-shaped stainless steels;

[0100] 2) splicing and welding two L-shaped stainless steels welded with PBL plates 3 to form a stainless steel pipe 2 structure;

[0101] 3) The stainless steel tube 2 is used as the external formwork, and the internal cavity formwork adopts an inflatable rubber inner formwork or a corrugated steel plate inner formwork, wherein the corrugated steel plate inner formwork is disposable to strengthen the interaction between the inner and outer concrete interfaces, and the inflatable rubber inner formwork is easy to disassemble and can be reused;

[0102] 4) According to the design requirements, the longitudinal steel bars and the annular stirrups or the spiral stirrups are tied together to form a steel cage 4;

[0103] 5) Place the tied steel cage 4 into the stainless steel pipe 2 and pour the ultra-high performance concrete. After one-time pouring and forming, remove the inner mold to form a prefabricated steel-concrete rectangular composite column formwork;

[0104] S2: Cast-in-place prefabricated steel-concrete rectangular composite columns. The specific steps are as follows:

[0105] 1) Fix the steel section 5 at a predetermined position to ensure its stability during the construction process;

[0106] Then, the high-performance formwork is accurately mounted on the outside of the steel section 5 to ensure that the gap between the high-performance formwork and the steel section 5 meets the design requirements;

[0107] 2) pouring ordinary concrete 6 to ensure that the ordinary concrete 6 is evenly distributed and completely fills the formwork to avoid voids or unevenness. After the curing is completed, a complete stainless steel-UHPC formwork type prefabricated assembled steel-concrete rectangular composite column is finally formed.

[0108] Example 2

[0109] A prefabricated steel-concrete rectangular composite column, comprising a high-performance formwork, the high-performance formwork comprising an outer shell 1, a stainless steel pipe 2 wrapped outside the outer shell 1, a plurality of PBL plates 3 arranged in the stainless steel pipe 2, and a steel cage 4 arranged in the outer shell 1;

[0110] Also includes a steel section 5 disposed in the high performance formwork;

[0111] The shell is the core structure of this assembly column. The shell 1 is made of UHPC ultra-high performance concrete to ensure the high strength, durability and earthquake resistance of the column;

[0112] C50 grade ordinary concrete 6 is poured between the high performance formwork and the steel section 5.

[0113] The cross-sectional shape of the high-performance mold shell is rectangular, and the outer and inner surfaces of the cylinder are both flat.

[0114] Combination Figure 1 , Figure 2 and Figure 4 The outer surface of the shell 1 is wrapped with a thin-walled stainless steel tube 2. On the one hand, the brittle characteristics of UHPC are overcome by wrapping the stainless steel tube 2, thereby improving the ductility of the component; on the other hand, the stainless steel tube 2 and UHPC are prefabricated into a formwork with a certain strength and rigidity, which plays a role in protecting the ultra-high performance concrete from external environmental erosion;

[0115] Several evenly distributed PBL plates 3 are welded on the inner wall of the stainless steel tube 2. The PBL plates 3 are designed in the form of round holes or long hole grooves. On the one hand, the PBL plates can delay the buckling of the stainless steel tube 2, and on the other hand, improve the connection quality with the UHPC components and enhance the overall performance of the structure.

[0116] Combination Figure 5 The steel cage 4 is arranged inside the ultra-high performance concrete pipe 1 to enhance the structural strength of the ultra-high performance concrete pipe 1. The steel cage 4 is composed of longitudinal steel bars and stirrups, and provides additional tensile and compressive resistance through combination with concrete. There are two ways to design the stirrups of the steel cage 4: parallel wrapping (C1-C1) and spiral wrapping (C2-C2). The stirrups should be continuous spiral composite high-strength stirrups, preferably with a smaller spacing, to enhance the lateral constraint of the prefabricated formwork on the post-poured concrete, improve the deformation capacity and ductility of the composite column, ensure good seismic performance, and effectively prevent the outer high-performance or ultra-high performance concrete from bursting in a fire, thereby improving the fire resistance.

[0117] Combination Figure 6 and Figure 7 At the construction site, the steel 5 is first fixed at a predetermined position, and then the formwork is inserted into the outside of the steel 5, and finally the ordinary concrete 6 is poured to ensure that the ordinary concrete 6 is evenly filled to avoid voids or unevenness, and to ensure the density and integrity of the structure. A complete stainless steel-UHPC formwork steel concrete composite column is formed.

[0118] A construction method based on a prefabricated steel-concrete rectangular composite column includes the following steps:

[0119] S1: Material preparation, the specific steps are as follows:

[0120] 1) Select UHPC materials that meet the standards, whose main components include cement, fine aggregate, coarse aggregate, steel fiber, water reducer, etc. The specific mix ratio is: cement: fine aggregate: coarse aggregate: steel fiber: water reducer = 1: 2.5: 1.5: 0.03: 0.01 (mass ratio). The length of the steel fiber is 12mm, the diameter is 0.2mm, the tensile strength is ≥ 1500MPa, and the elastic modulus is ≥ 200GPa. The water reducer is a high-efficiency water reducer with a water reduction rate of ≥ 25%.

[0121] 2) 304 stainless steel is used, which has good corrosion resistance and strength. The thickness of the stainless steel pipe is 5mm, and the outer diameter is determined according to the design requirements;

[0122] 3) The PBL plate is made of high-strength steel plate with a thickness of 3mm. The surface is processed into a round hole or a long hole groove shape. The round hole diameter is 20mm, the long hole size is 20mm×50mm, and the hole spacing is 50mm. The tensile strength of the PBL plate is ≥500MPa, and the yield strength is ≥300MPa;

[0123] 4) The longitudinal reinforcement is HRB400 grade steel bar with a diameter of 12mm, a yield strength of ≥400MPa, and a tensile strength of ≥540MPa. The circular stirrups or spiral stirrups are also HRB400 grade steel bars with a diameter of 6mm and a stirrup spacing of 100mm. The size of the steel cage is determined according to the design requirements of the composite column to ensure that it can be completely wrapped in the ultra-high performance concrete shell;

[0124] 5) Select Q345B grade steel, which has good strength and rigidity. The specifications of the steel are determined according to the design bearing capacity and cross-sectional dimensions of the composite column;

[0125] 6) Use C50 grade ordinary concrete, whose main components include cement, fine aggregate, coarse aggregate, water, etc. The specific mix ratio is: cement: fine aggregate: coarse aggregate: water = 1:2.5:3.5:0.5 (mass ratio). Cement is silicate cement with a strength grade of 42.5. Fine aggregate is river sand with a fineness modulus of 2.5. Coarse aggregate is crushed stone with a particle size of 5mm-25mm.

[0126] S2: Prefabricated high-performance formwork is prepared in the factory. The specific steps are as follows:

[0127] 1) Cut the 304 stainless steel plate into an L shape according to the design size. Arrange the processed PBL plates evenly along the length direction of the L-shaped stainless steel, with the long side of the PBL plate parallel to the long side of the L-shaped stainless steel, and the short side perpendicular to the short side of the L-shaped stainless steel. The spacing between adjacent PBL plates is 1 / 3 of the length and width along the section. Use welding equipment to weld the PBL plate into the L-shaped stainless steel, with the weld length being twice the width of the PBL plate and the weld height being 3 mm;

[0128] 2) Splice two L-shaped stainless steels welded with PBL plates together to form a complete stainless steel pipe structure. When splicing, align the long sides of the two L-shaped stainless steels and fit the short sides together. Use welding equipment to weld the short sides of the two L-shaped stainless steels together. The length of the weld is twice the length of the short side and the weld height is 3mm. Ensure that the welding is firm and there are no defects such as pores and slag inclusions in the weld.

[0129] 3) According to the design requirements, HRB400 grade steel bars are cut into the required length and made into longitudinal steel bars and annular stirrups or spiral stirrups. The length of the longitudinal steel bars is the height of the composite column, and the length of the annular stirrups or spiral stirrups is the height of the composite column minus the thickness of the protective layer at both ends.

[0130] Tie the longitudinal reinforcement and the circular or spiral stirrups together to form a reinforcement cage. When tying, use iron wire to fix the stirrups to the longitudinal reinforcement, with a spacing of 100mm between the tying points to ensure that the shape of the reinforcement cage is regular and the size is accurate.

[0131] 4) Place the prepared steel cage into the stainless steel pipe, with the center of the steel cage coinciding with the center of the stainless steel pipe, and the two ends of the steel cage flush with the two ends of the stainless steel pipe. In the internal cavity of the stainless steel pipe, select a suitable inner mold according to the design requirements, which can be an inflatable rubber inner mold or a corrugated steel plate inner mold. The inflatable rubber inner mold is easy to disassemble and reuse, and is suitable for small-scale production; the corrugated steel plate inner mold is disposable, which can strengthen the interaction between the inner and outer concrete interfaces and is suitable for large-scale production. Fix the inner mold inside the stainless steel pipe to ensure that the inner mold fits tightly against the inner wall of the stainless steel pipe. Then, inject the prepared UHPC material into the stainless steel pipe through the concrete pouring equipment. The pouring should be continuous and uniform to avoid bubbles and voids. After the pouring is completed, perform appropriate vibration to make the concrete dense. After the UHPC solidifies and hardens, remove the inner mold to form the shell part of the prefabricated stainless steel-UHPC shell steel concrete rectangular composite column;

[0132] S3: Cast-in-place prefabricated steel-concrete rectangular composite columns. The specific steps are as follows:

[0133] 1) At the construction site, according to the design drawings and construction plan, fix the Q345B grade steel in the predetermined position. When fixing, you can use embedded parts or support frames to fix the steel on the foundation or existing structure to ensure the stability of the steel and prevent displacement or tilt during construction. The fixed position of the steel should meet the design requirements, and the deviation range should be controlled within ±5mm.

[0134] 2) Accurately fit the prefabricated formwork on the outside of the steel section. The gap between the formwork and the steel section should meet the design requirements. When fitting, ensure that the center of the formwork coincides with the center of the steel section, and the two ends of the formwork are flush with the two ends of the steel section. The formwork can be hoisted to the construction site using lifting equipment, and appropriate adjustments and positioning can be made during the fitting process.

[0135] 3) Pour C50 grade ordinary concrete between the formwork and the steel. The pouring should be continuous and uniform to avoid bubbles and voids. Concrete pouring equipment can be used to inject concrete into the gap between the formwork and the steel. The pouring height should be consistent with the height of the formwork. After pouring, vibrate appropriately to make the concrete dense. After the concrete solidifies and hardens, it is cured. The curing time is generally 28 days. During this period, the concrete surface should be kept moist to prevent cracks caused by drying and shrinkage.

[0136] 4) During the construction process and after construction is completed, strict quality inspections and acceptance should be carried out. The inspection contents include: the fixed position and stability of the profiled steel, the sleeved position and gap of the formwork, the pouring quality and density of the concrete, the appearance and dimensions of the composite column, etc. The acceptance criteria should comply with relevant codes and design requirements to ensure that the quality and performance of the composite column reach the expected goals.

[0137] Example 3

[0138] On the basis of Example 1, it also includes an auxiliary bracket for hoisting and installation;

[0139] The auxiliary bracket includes two bottom plates 13 and two U-shaped clamps 11 arranged in butt joint. Connecting ear plates 12 are arranged on both sides of each U-shaped clamp 11, and the two U-shaped clamps 11 are fixedly connected to the outer wall of the stainless steel pipe 2 through bolts; See Figure 8 ;

[0140] A vertical electric push rod 14 is arranged at one end of the bottom plate 13 close to the U-shaped clamp 11;

[0141] Connecting seats 15 are arranged at one end of the bottom plate 13 far from the U-shaped clamp 11 and on the outer wall of the U-shaped clamp 11, and a telescopic rod 16 is arranged between the two connecting seats 15.

[0142] The fixed end of the vertical electric push rod 14 is fixedly arranged on the upper surface of the bottom plate 13, and the end of the telescopic end of the vertical electric push rod 14 is fixedly connected to the outer wall of the U-shaped clamp 11.

[0143] The U-shaped clamp 11 is used to be fixed on the outer wall of the stainless steel pipe 2 to provide a stable support point.

[0144] The function of the vertical electric push rod 14 is to provide a vertical thrust to adjust the position of the formwork in the vertical direction to ensure the precise docking between the formwork and the profiled steel.

[0145] The role of the auxiliary bracket during installation and hoisting is as follows:

[0146] Provide vertical adjustment ability: The vertical electric push rod 14 can precisely adjust the position of the formwork in the vertical direction to ensure that the gap between the formwork and the profiled steel meets the design requirements, thus guaranteeing the installation quality and structural performance of the composite column.

[0147] Enhance stability: The U-shaped clamp 11 is fixed on the outer wall of the stainless steel pipe 2 to provide stable support for the formwork, prevent the formwork from shaking or displacing in the vertical direction during hoisting, and ensure the stability of the hoisting process.

[0148] Improve installation accuracy: Through the fine-tuning function of the vertical electric push rod 14, the vertical position between the mold shell and the steel section can be accurately docked, the installation accuracy of the combined column can be improved, and the integrity and stability of the structure can be ensured.

[0149] The fine-tuning function of the vertical electric push rod 14 can ensure that the vertical position between the formwork and the steel section is accurately controlled within the design range, thereby improving the installation accuracy of the combined column and ensuring the integrity and stability of the structure.

[0150] The stable support of the U-shaped clamp 11 can effectively prevent the formwork from shaking and displacing in the vertical direction during the lifting process, reduce structural damage or safety accidents caused by improper lifting, and enhance the safety of the construction process.

[0151] The traditional installation method requires a lot of manual work for vertical adjustment and calibration, which is labor-intensive. The use of the vertical electric push rod 14 can reduce the number and difficulty of manual adjustment, reduce labor intensity, and improve the work efficiency of construction personnel.

[0152] The rapid positioning and fixing function of the vertical electric push rod 14 can greatly shorten the vertical installation time of the formwork and the steel, improve the construction efficiency, and thus speed up the construction progress of the entire project.

[0153] Example 4

[0154] Based on Example 3, see Figure 8 The telescopic rod 16 includes an inner rod and an outer rod which are sleeved together, two connecting seats 15 are respectively hinged to one end of an outer rod, and an inner rod is slidably arranged between the two outer rods;

[0155] Through holes are provided on the side walls of the inner rod and the outer rod, and the inner rod and the outer rod are fixedly connected by bolts fixing the through holes.

[0156] The function of the telescopic rod 16 is to provide horizontal adjustment capability. By the relative sliding of the inner rod and the outer rod, the position of the mold shell in the horizontal direction can be adjusted to ensure the precise docking between the mold shell and the steel section.

[0157] The provision of the telescopic rod 16 can effectively prevent the formwork from shaking or shifting in the horizontal direction during the hoisting process, thereby ensuring the stability of the hoisting process.

[0158] Through the fine-tuning function of the telescopic rod 16, the horizontal position between the formwork and the steel section can be accurately docked, the installation accuracy of the combined column can be improved, and the integrity and stability of the structure can be ensured.

[0159] The traditional installation method requires a lot of manual work to adjust and calibrate the horizontal direction, which is labor-intensive. The use of the telescopic rod 16 can reduce the number and difficulty of manual adjustment, reduce labor intensity, and improve the work efficiency of construction personnel.

[0160] The rapid positioning and fixing function of the telescopic rod 16 can greatly shorten the horizontal installation time of the formwork and the steel section, improve the construction efficiency, and thus speed up the construction progress of the entire project.

[0161] Through the auxiliary bracket design of Example 3 and Example 4, the installation accuracy and construction efficiency of the prefabricated steel-concrete rectangular composite column can be significantly improved, while the safety and stability of the construction process can be enhanced.

[0162] Example 5

[0163] Based on Example 1, see Fig. 9 and Fig.10 , and also includes a support adjustment mechanism that plays an auxiliary support and positioning role when the prefabricated steel-concrete composite column and the composite beam are connected;

[0164] The support adjustment mechanism includes two U-shaped clamps 21 that are butt-jointed, and each U-shaped clamp 21 is provided with connecting ear plates 22 on both sides. The two U-shaped clamps 21 are fixedly connected to the outer wall of the stainless steel pipe 2 by bolts;

[0165] The top of the U-shaped clamp 21 is provided with a top plate 23;

[0166] Both ends of each top plate 23 are provided with electric push rods 25, the telescopic ends of the two electric push rods 25 are arranged opposite to each other, and push plates 26 are fixedly provided at the ends of the telescopic ends of the electric push rods 25, and the two push plates 26 fix the composite beam from both sides;

[0167] The edge of the top plate 23 is provided with scale lines 27 for locating the position of the push plate 26 .

[0168] A notch 24 is formed on one side of the top plate 23 close to the stainless steel tube 2 , and the notch 24 corresponds to the groove of the U-shaped clamp 21 .

[0169] The working principle of the support adjustment mechanism is as follows:

[0170] (1) Install the support adjustment mechanism

[0171] The two U-shaped clamps 21 are fixed to the outer wall of the stainless steel pipe of the combined column by bolts.

[0172] Install the top plate 23 and align it with the groove of the second U-shaped clamp through the notch 24.

[0173] Electric push rods 25 are installed at both ends of the top plate, and a push plate 26 is fixed.

[0174] (2) Composite beam hoisting and preliminary positioning

[0175] Lift the composite beam above the composite column and preliminarily adjust its position so that it is aligned with the connection part of the composite column.

[0176] Adjust the telescopic end of the electric push rod 2 so that the push plate 26 contacts the two sides of the composite beam.

[0177] (3) Precision adjustment and support

[0178] According to the indication of the scale line 27, the telescopic length of the electric push rod 2 is finely adjusted to accurately control the position of the composite beam and ensure the connection accuracy between it and the composite column.

[0179] The electric push rod 2 applies appropriate supporting force to fix the composite beam to prevent it from displacement or overturning during the subsequent construction process.

[0180] (4)Complete connection and removal

[0181] Complete the final connection construction (such as welding, bolt connection, etc.) at the connection point between the composite beam and the composite column.

[0182] After the concrete pouring of the connecting parts is completed and reaches the designed strength, the supporting and adjusting mechanism is removed to complete the construction.

[0183] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A prefabricated steel-concrete rectangular composite column, characterized in that: It includes a high-performance formwork, and the high-performance formwork includes a housing (1), a stainless steel pipe (2) wrapped outside the housing (1), several PBL plates (3) arranged inside the stainless steel pipe (2), and a steel reinforcement cage (4) arranged inside the housing (1); It also includes a steel section (5) arranged inside the high-performance formwork; The housing (1) is made of UHPC ultra-high performance concrete; Ordinary concrete (6) is poured between the high-performance formwork and the steel section (5).

2. The prefabricated steel-concrete rectangular composite column according to claim 1 is characterized in that: The cross-sectional shape of the high-performance formwork is rectangular, and both the cylindrical outer surface and the inner surface are flat surfaces.

3. The prefabricated steel-concrete rectangular composite column according to claim 1 is characterized in that: The outer surface of the housing (1) is wrapped with a thin-walled stainless steel pipe (2), and several uniformly distributed PBL plates (3) are welded on the inner wall of the stainless steel pipe (2).

4. The prefabricated steel-concrete rectangular composite column according to claim 1 is characterized in that: The steel reinforcement cage (4) is composed of longitudinal steel bars and circular stirrups or spiral stirrups.

5. A construction method for prefabricated steel-concrete rectangular composite columns according to any one of claims 1 to 4, characterized in that: It includes the following steps: S1: Prepare precast high-performance formwork in the factory, and the specific steps are as follows: 1) According to the design dimensions, select two L-shaped stainless steels, and arrange the PBL plates (3) uniformly along the length direction of the L-shaped stainless steels and weld them inside the L-shaped stainless steels; 2) Splice and weld the two L-shaped stainless steels welded with PBL plates (3) to form a stainless steel pipe (2) structure; 3) The stainless steel pipe (2) is used as an external formwork, and an inflatable rubber inner formwork or a corrugated steel plate inner formwork is used as the internal cavity formwork; 4) According to the design requirements, bind the longitudinal steel bars and circular stirrups or spiral stirrups together to form a steel reinforcement cage (4); 5) Place the bound steel reinforcement cage (4) into the stainless steel pipe (2), and pour ultra-high performance concrete. After one-time pouring and forming, remove the inner formwork to form a precast assembled steel-concrete rectangular composite column formwork; S2: Cast the precast assembled steel-concrete rectangular composite column on-site, and the specific steps are as follows: 1) Fix the steel section (5) at a predetermined position to ensure its stability during construction; Subsequently, accurately sleeve the high-performance formwork outside the steel section (5) to ensure that the gap between the high-performance formwork and the steel section (5) meets the design requirements; 2) Pour ordinary concrete (6). After curing is completed, finally form a complete stainless steel-UHPC formwork type precast assembled steel-concrete rectangular composite column.

6. The construction method of prefabricated steel-concrete rectangular composite columns according to claim 5 is characterized in that: It also includes an auxiliary support for hoisting and installation; The auxiliary support includes two bottom plates (13) and two U-shaped clamps (11) arranged in a butt joint. Connecting ear plates (12) are arranged on both sides of each U-shaped clamp (11), and the two U-shaped clamps (11) are fixedly connected to the outer wall of the stainless steel pipe (2) through bolts; A vertical electric push rod (14) is arranged at one end of the bottom plate (13) close to the U-shaped clamp (11); Connecting seats (15) are arranged at one end of the bottom plate (13) far from the U-shaped clamp (11) and on the outer wall of the U-shaped clamp (11), and a telescopic rod (16) is arranged between the two connecting seats (15).

7. The construction method of prefabricated steel-concrete rectangular composite columns according to claim 6 is characterized in that: The fixed end of the vertical electric push rod (14) is fixedly arranged on the upper surface of the bottom plate (13), and the telescopic end of the vertical electric push rod (14) is fixedly connected to the outer wall of the U-shaped clamp (11).

8. The construction method of prefabricated steel-concrete rectangular composite columns according to claim 6 is characterized in that: The telescopic rod (16) comprises an inner rod and an outer rod which are sleeved together, the two connecting seats (15) are respectively hinged to one end of an outer rod, and the inner rod is slidably arranged between the two outer rods; The inner rod and the outer rod are both provided with through holes on their side walls, and the inner rod and the outer rod are fixedly connected by bolts fixing the through holes.

9. The construction method of prefabricated steel-concrete rectangular composite columns according to claim 1, characterized in that: It also includes a support adjustment mechanism that plays an auxiliary support and positioning role when the prefabricated steel-concrete composite column and composite beam are connected; The support adjustment mechanism comprises two U-shaped clamps (21) arranged in a butt joint, each of the U-shaped clamps (21) is provided with connecting ear plates (22) on both sides, and the two U-shaped clamps (21) are fixedly connected to the outer wall of the stainless steel pipe (2) by bolts; A top plate (23) is provided on the top of the second U-shaped clamp (21); Both ends of each of the top plates (23) are provided with electric push rods (25), the telescopic ends of the two electric push rods (25) are arranged opposite to each other, and push plates (26) are fixedly provided at the ends of the telescopic ends of the two electric push rods (25), and the two push plates (26) fix the combined beam from both sides; The edge of the top plate (23) is provided with a scale mark (27) for locating the position of the push plate (26).

10. The construction method of prefabricated steel-concrete rectangular composite columns according to claim 9, characterized in that: The top plate (23) is provided with a notch (24) on one side close to the stainless steel pipe (2), and the notch (24) corresponds to the groove of the second U-shaped clamp (21).

Images