Formwork-free high-ductility material fabricated composite column

Abstract

The invention relates to the technical field of fabricated structures, and discloses a formwork-free high-ductility material fabricated composite column, which comprises a plurality of groups of prefabricated outer plates, the outer plates are spliced with one another to form a hollow shell, and fillers are poured in the shell, and the formwork-free high-ductility material fabricated composite column is characterized in that at least one row of truss ribs is embedded in the single outer plate; the truss ribs extend towards the interiors of the shells and form hooks on the two sides of the adjacent shells, and the adjacent hooks are overlapped and then penetrate into the reserved longitudinal ribs to fasten the adjacent outer plates. A cavity in the shell is filled with light environment-friendly filler; and the material for manufacturing the outer plate is selected from a high-ductility material. According to the formwork-erecting-free high-ductility material assembly type composite column, the outer plates and the truss ribs are poured into the prefabricated outer plates, the two sides of each prefabricated outer plate are each provided with a row of hooks, longitudinal reserved steel bars are inserted into the hooks in a penetrating mode, the four prefabricated outer plates are spliced into a hollow box type structure, and the hollow composite column is formed; the reserved steel bars inserted into the hooks can provide bolt pin force, and the crack resistance and the shear bearing capacity of the structure are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of assembled structures, and in particular to a formwork-free assembled composite column made of high-ductility materials. Background Art

[0002] In the field of construction engineering, composite columns are an important structural component and are widely used in various types of buildings. However, the existing composite column technology still has some problems that need to be solved in practical applications.

[0003] Prior art 1:

[0004] Traditional solid concrete columns, due to their excessive deadweight, present significant inconvenience during transportation and hoisting. This not only increases construction difficulty but can also lead to increased costs. This issue is particularly prominent in high-rise buildings and large-scale projects, severely impacting construction efficiency and progress.

[0005] Prior art 2:

[0006] The existing Chinese patent publication number CN118481299A provides a high-strength concrete composite column and a construction method. The composite column includes a core concrete layer, a high-strength concrete layer, and a connection structure. A through cavity 1 is provided at the inner center of the high-strength concrete layer. A steel bar skeleton is passed through the inner part of the high-strength concrete layer. A surface treatment layer is evenly applied to the outer wall of the high-strength concrete layer. The connection structure is provided inside the through cavity 1. A through cavity 2 is provided at the inner center of the connection structure. A plurality of equidistant connection grooves are provided on the four sides of the bottom of the connection structure. The core concrete layer is provided inside the through cavity 2. A steel bar skeleton is passed through the inner part of the core concrete layer. The composite column of the present invention adopts a combination of high-strength concrete and a steel bar skeleton. The design of the connection structure and the connection groove achieves a tight connection between the core concrete and the high-strength concrete layer. At the same time, the surface treatment layer is applied to the outer wall to improve the waterproof, anti-corrosion and wear-resistant properties of the column. This composite column not only has a higher load-bearing capacity and durability, but also has a simple construction process.

[0007] Existing technology three:

[0008] A Chinese patent, publication number CN222120738U, discloses a hollow column structure with a non-removal formwork. The structure comprises two opposing precast concrete slabs and two opposing non-removal formwork, which enclose a column cavity. A steel mesh is located within the column cavity, with both sides of the mesh cast into the two precast concrete slabs. Side panels are provided on either side of the precast concrete slabs, with the non-removal formwork tightly connected to the side panels. Embedded reinforcement is connected to the side panels, which are cast into the precast concrete slabs. A welding ring is provided within the non-removal formwork, welded to the side panels. The inner ring side of the welding ring forms a welding cavity, which extends through the non-removal formwork, exposing the side panels to the outside of the non-removal formwork through the welding cavity. The non-removal formwork is cast and formed, with the welding ring embedded in the non-removal formwork. Connecting reinforcement is connected to the welding ring, which is embedded in the non-removal formwork.

[0009] The defects of the above prior art are as follows:

[0010] 1. The traditional composite column in the existing technology is too heavy, which makes transportation and lifting inconvenient:

[0011] 2. The existing technology uses a cumbersome formwork and dismantling process. This technology often requires additional formwork during the production of composite columns. This cumbersome and time-consuming process not only increases construction workload, but the use and recycling of formwork can also lead to additional environmental impact and waste of resources.

[0012] 3. The prefabricated composite columns provided by the third prior art have poor crack resistance of ordinary concrete, which is difficult to meet the high requirements of modern buildings for structural durability and safety. During long-term use, concrete is prone to cracks and breakage, which affects the overall performance and life of the composite columns. However, engineered cement-based composites (ECC) effectively make up for this shortcoming with their unique crack development characteristics - numerous and dense fine cracks. ECC can form a large number of fine crack networks when subjected to stress. These cracks can disperse and absorb stress, thereby significantly enhancing the crack resistance of concrete and extending the service life of the composite columns.

[0013] 4. Existing technologies suffer from a shortage of coarse aggregate and underutilization of resources: Coarse aggregate is crucial in concrete production. However, with the development of the construction industry, resource shortages and rising prices are driving up costs and putting pressure on the environment. Furthermore, coal gangue, as coal mine waste, accumulates and pollutes the environment. Therefore, utilizing coal gangue as coarse aggregate, achieving both recycling and environmental protection, is a pressing issue for the construction industry. Summary of the Invention

[0014] The purpose of the present invention is to provide a high-ductility assembled composite column made of materials that does not require formwork, which is used to solve the problems of heavy weight, low seismic performance and crack resistance and tensile strength of assembled integral composite columns in the prior art, reduce the time for lifting and formwork support and dismantling during on-site construction, and improve construction efficiency.

[0015] The present invention provides the following technical solutions:

[0016] A formwork-free assembled composite column made of high-ductility material, comprising several groups of prefabricated outer panels, which are spliced together to form a hollow shell, and filler is cast inside the shell. The invention is characterized in that at least one row of truss bars is embedded in a single outer panel, and the truss bars extend toward the interior of the shell and form hooks on both sides of adjacent shells. Adjacent hooks overlap and penetrate reserved longitudinal bars to fasten adjacent outer panels; the cavity inside the shell is filled with lightweight environmentally friendly filler; and the material for making the outer panels is selected from high-ductility materials.

[0017] According to some embodiments, the material used to make the outer panel is selected from ECC material or UHPC material.

[0018] According to some embodiments, the lightweight environmentally friendly filler is selected from coal gangue aggregate, waste glass aggregate or waste rubber particles.

[0019] According to some embodiments, the components of the gangue aggregate are water, ordinary Portland cement, natural sand, water reducer, crushed stone and non-natural gangue, and the non-natural gangue is continuously graded gangue with a particle size of 4.75-19 mm, and the mass ratio thereof is 1:2.13:4.18:0.032:4.22:1.37, wherein the water-binder ratio is 0.47.

[0020] According to some embodiments, the components of the ECC material are water, ordinary Portland cement, quartz sand, fly ash, water reducer and PVA fiber, and the mass ratio thereof is 1:1.25:1:1.53:0.01:0.058, wherein the water-binder ratio is 0.36.

[0021] According to some embodiments, each row of the truss bars includes multiple groups, and a single group of the truss bars includes transverse stirrups, upper chord steel bars, lower chord steel bars and web steel bars. The stirrups are pre-cast in the outer plate, and both ends extend out of the outer plate to form hooks. After adjacent hooks overlap, reserved longitudinal bars are fixed therein; the lower chord steel bars fixed on the stirrups are fixedly connected to the upper chord steel bars through the web steel bars.

[0022] According to some embodiments, the housing is cylindrical or prism-shaped with a regular polygonal cross section.

[0023] According to some embodiments, when the shell is prismatic, the number of the outer panels is at least four, and the cross-section thereof is trapezoidal.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention provides a prefabricated composite column made of high-ductility material without formwork, in which outer panels and truss bars are cast into prefabricated outer panels. Each prefabricated outer panel has a row of hooks on both sides. The longitudinal reserved steel bars are inserted into the hooks, and the four prefabricated outer panels are spliced into a box-type structure to form a hollow composite column. The reserved steel bars inserted into the hooks can provide pinning force, thereby improving the crack resistance and shear bearing capacity of the structure.

[0026] (2) In terms of internal structure, the truss reinforcement serves as the skeleton of the prefabricated outer panel to improve its rigidity and crack resistance, and also as the load-bearing reinforcement of the composite column. At the same time, it connects the prefabricated outer panel with the post-cast coal gangue concrete so that the two can bear the load together.

[0027] (3) The cross-section of the outer plate is trapezoidal, which makes the cavity inside the spliced hollow composite column larger, and the density of the coal gangue concrete poured later is better, and the structural integrity is basically the same as that of cast-in-place.

[0028] (4) Use ECC or UHPC materials with high ductility to manufacture the outer panels, and pour coal gangue concrete in the spliced hollow columns to form composite columns without formwork. In this way, the prefabricated outer panels serve as templates, are light in weight during hoisting, and are easy to position. After positioning, they are integrated with the coal gangue concrete poured later, which simplifies the on-site formwork process, improves on-site construction efficiency, and reduces labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the prefabricated outer panel provided in Example 1 of the present invention.

[0030] Figure 2 Schematic diagram of the inner reinforcement of the prefabricated outer plate provided in Example 1 of the present invention.

[0031] Figure 3 This is the vertical reserved longitudinal reinforcement diagram provided in Example 1 of the present invention.

[0032] Figure 4 This is a top cross-sectional view of the hollow outer panel provided in Example 1 of the present invention.

[0033] Figure 5 This is a schematic diagram of post-cast coal gangue concrete provided in Example 1 of the present invention.

[0034] Figure 6 This is a cross-sectional view of the top of the composite column after casting provided in Example 1 of the present invention.

[0035] Figure 7This is a schematic diagram of the assembly of the formwork-free, high-ductility prefabricated composite column provided in Example 1 of the present invention.

[0036] Figure 8 This is a top cross-sectional view of the composite column provided in Example 2 of the present invention.

[0037] Figure 9 This is the tensile stress-strain curve of the ECC material provided by the embodiment of the present invention.

[0038] Figure 10 This is the ECC crack development situation provided by the embodiment of the present invention.

[0039] In the picture:

[0040] Truss reinforcement 1; upper chord reinforcement 11; lower chord reinforcement 12; web reinforcement 13; hook 2; ECC slab 3; reserved longitudinal reinforcement 4; post-poured coal gangue concrete 5. DETAILED DESCRIPTION

[0041] The present invention is described in detail below with reference to the embodiments and accompanying drawings. However, it should be understood that the embodiments and accompanying drawings are merely exemplary descriptions of the present invention and do not constitute any limitation on the scope of protection of the present invention. All reasonable variations and combinations within the scope of the inventive concept of the present invention fall within the scope of protection of the present invention.

[0042] The present invention will be further described below with reference to the accompanying drawings.

[0043] Example 1

[0044] like Figure 1-7 This embodiment provides a formwork-free, high-ductility composite column, hereinafter referred to as a composite column, which includes four sets of spliced outer plates and a post-cast coal gangue concrete 5 in the middle. Figure 1 In this embodiment, a single outer plate is made of ECC material and includes an ECC plate 3. The cross section of the ECC plate 3 is approximately trapezoidal, with the short side of the trapezoid facing inward. Multiple rows of truss bars 1 are cast and embedded in the ECC plate 3. Each row of truss bars 1 includes multiple groups. The truss bars 1 include transverse stirrups, upper chord bars 11, lower chord bars 12, and web bars 13 pre-cast in the ECC plate 3. Figure 4, stirrups are pre-cast inside the ECC plate 3, with both ends extending out of the ECC plate 3 to form hooks 2. Adjacent hooks 2 are overlapped and fixed with the reserved longitudinal bars 4, so that each steel bar is connected together to form a circle, thereby forming a ring-shaped stirrup. The ring-shaped stirrup can improve the shear resistance of the composite column, and can also constrain the concrete and enhance the stability of the composite column. The lower chord steel bars 12 are fixed on the stirrups, and the two lower chord steel bars 12 are arranged inside the ECC plate 3, and the upper chord steel bars 12 are arranged outside the ECC plate 3, and are connected by the web bars 13; the lower chord steel bars 12 serve as the stress-bearing steel bars at the bottom of the ECC plate 3, which can save steel; the upper chord steel bars 11 can be used as a lifting point, so the ECC plate 3 does not need to be equipped with a lifting point; the web bars 13 weld the upper chord steel bars and the lower chord steel bars together, so that the truss bar 1 forms a triangular cross-section.

[0045] like Figure 7 , a number of hooks 2 are arranged vertically on the two oblique sides of the trapezoid of the ECC plate 3, and the upper and lower hooks 2 on adjacent ECC plates 3 overlap each other, and the reserved longitudinal reinforcement 4 is vertically passed through and fixed by stirrups, such as Figure 3 、 Figure 4 and Figure 6 Four prefabricated ECC panels 3 are spliced together to form a box-shaped structure with a hollow interior and a solid exterior, forming a hollow ECC column. The reserved steel bars 4 not only connect the ECC panels together but also provide pinning force, improving the shear bearing capacity of the column.

[0046] The shell of the composite column is made of four spliced ECC plates 3, on which truss bars 1 and vertical reserved longitudinal bars 4 are inlaid. The shell is manufactured in the factory and poured and connected to form an integral composite column shell.

[0047] After the shell of the composite column is assembled, it is transported to the site for positioning. Filling is poured into the shell of the composite column. In this embodiment, coal gangue concrete is selected. After solidification, post-cast coal gangue concrete 5 is formed. Figure 5 , and finally form the ECC-coal gangue concrete prefabricated composite column that bears the same load and does not require formwork.

[0048] Among them, the apparent density of coal gangue is roughly 2590kg / m 3 About, the bulk density is 1330kg / m 3 The apparent density of ordinary crushed stone is about 2740kg / m 3 About, the bulk density is 1780kg / m 3 Using coal gangue aggregate instead of traditional coarse aggregate can reduce the density of concrete by 20%-25%, which can greatly reduce the weight of components. The density of ECC materials is usually 1600-2000kg / m 3The density of coal gangue aggregate is much lower than that of ordinary Portland cement. Therefore, the use of coal gangue aggregate instead of traditional coarse aggregate and ECC material can greatly reduce the deadweight of column components, which has obvious lightweight advantages and can significantly reduce earthquake inertia and post-earthquake residual deformation of the structure.

[0049] like Figure 9 Conventional concrete, commonly used in traditional engineering, typically experiences an ultimate tensile strain of around 2% under tension and can suffer brittle failure. ECC, however, possesses exceptionally high toughness. At a fiber volume content of 2%, ECC's ultimate tensile strain can reach around 3%. Under tensile and shear loads, ECC exhibits high ductility, significant strain hardening, and multiple cracking. This allows the structure to withstand significant deformation during earthquakes without immediate collapse or failure, demonstrating significant ductile failure characteristics. This improves the structure's safety reserve capacity, thereby reducing the potential for property damage and casualties.

[0050] In addition, if Figure 10 , ECC materials, with their outstanding high strength and high toughness characteristics, demonstrate extraordinary deformation tolerance and can maintain structural integrity even under extreme stress conditions. Its outstanding crack resistance is due to the addition of PVA fibers. These fibers can effectively disperse stress and inhibit crack expansion during the stress process, significantly reducing the risk of concrete cracking, thereby greatly improving the durability and service life of the structure. It is particularly worth mentioning that the multi-crack steady-state cracking mechanism of ECC materials ensures strict control of crack width, further consolidating its crack resistance. In addition, ECC also has a strong self-healing ability. Microfibers promote the self-repair of tiny cracks, reducing maintenance costs, significantly enhancing the long-term durability of the structure in a changing environment, and opening up new avenues for the innovation and application of building materials.

[0051] The ECC board 3 in this embodiment adopts ECC material, whose components are water, ordinary Portland cement, quartz sand, fly ash, water reducer and PVA fiber. Under normal circumstances, the water-binder ratio of ECC is generally 0.3-0.4, the water reducer dosage is 0.5%-2%, and the volume dosage of PVA fiber is 1%-2%. In order to ensure the strength and mechanical properties of the material, the mass ratio of each component in this embodiment is designed to be 1:1.25:1:1.53:0.01:0.058, among which the water-binder ratio is 0.36 and the volume dosage of PVA fiber is 2%. The post-cast gangue concrete 5 in the hollow ECC column is composed of water, ordinary Portland cement, natural sand, water reducer, crushed stone, and non-natural gangue. Typically, the water-binder ratio is 0.3-0.5, the gangue replacement rate is 0-100%, and the water reducer dosage is 0.5%-2%. To ensure material strength and mechanical properties, this embodiment uses continuously graded gangue with a particle size of 4.75-19 mm as coarse aggregate to replace 30% of the ordinary crushed stone. The mix ratio of the components is designed to be 1:2.13:4.18:0.032:4.22:1.37, with a water-binder ratio of 0.47. The water-binder ratio is an architectural term that refers to the ratio of water consumption to the total cementitious material consumption per cubic meter of concrete. The weight of cementitious material = the weight of cement + the weight of admixtures (such as fly ash, mineral powder, silica fume, zeolite powder, and other hydraulic or potentially hydraulic, pozzolanic or potentially pozzolanic materials, but excluding stone powder). The use of gangue material in this embodiment can greatly reduce the deadweight of the column, significantly reduce the seismic inertia force, and reduce the residual deformation of the structure after the earthquake. At the same time, the excellent deformation capacity and ultra-high toughness of the ECC material can be used to improve the tensile and crack resistance of the column. The use of ECC material also compensates for the brittleness of gangue concrete, promotes the application of gangue concrete in construction projects, and thus solves the environmental pollution problem caused by gangue accumulation.

[0052] Example 2

[0053] The present embodiment provides a high ductility composite column made of a formwork-free material. In the composite column structure, the overall shell is cylindrical, and the single ECC board 3 is a plurality of arc-shaped pieces, which are spliced together to form a cylindrical composite column. Figure 8 In some other embodiments, the housing is a prism with a regular polygonal cross section composed of multiple ECC plates 3, and there are at least four ECC plates 3.

[0054] Example 3

[0055] The formwork-free assembled composite column made of high-ductility materials provided in this embodiment can use other high-ductility materials such as UHPC materials to manufacture the shell in addition to ECC materials to enhance the crack resistance of the shell.

[0056] In addition to coal gangue aggregate, other waste materials with similar properties can also be considered as fillers for the cavity in the shell, such as waste glass aggregate, waste rubber particles, etc., to replace the coarse aggregate of traditional composite panels, so as to achieve the purpose of reducing material costs and environmental protection.

[0057] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of protection of the present invention are within the scope of protection of the present invention. It should be noted that improvements and modifications that can be made by a person skilled in the art without departing from the principles of the present invention are also considered to be within the scope of protection of the present invention.

Claims

1. A formwork-free, assembled composite column made of a highly ductile material, comprising a plurality of prefabricated outer panels joined together to form a hollow shell, wherein a filler is poured into the shell, characterized in that: At least one row of truss bars is embedded in a single outer panel. The truss bars extend toward the interior of the outer shell and form hooks on both sides of adjacent outer shells. Adjacent hooks overlap and penetrate into the reserved longitudinal bars to fasten the adjacent outer panels. The cavity in the outer shell is fully filled with lightweight environmentally friendly filler. The material for making the outer plate is selected from high ductility materials.

2. The formwork-free, high-ductility assembled composite column according to claim 1, characterized in that: The material for manufacturing the outer plate is selected from ECC material or UHPC material.

3. The formwork-free, high-ductility assembled composite column according to claim 2, characterized in that: The lightweight environmentally friendly filler is selected from coal gangue aggregate, waste glass aggregate or waste rubber particles.

4. The formwork-free, high-ductility assembled composite column according to claim 3, characterized in that: The components of the gangue aggregate are water, ordinary Portland cement, natural sand, water reducer, crushed stone and non-natural gangue. The non-natural gangue is continuously graded gangue with a particle size of 4.75-19 mm, and the mass ratio is 1:2.13:4.18:0.032:4.22:1.37, wherein the water-binder ratio is 0.

47.

5. The formwork-free, high-ductility assembled composite column according to claim 2, characterized in that: The components of the ECC material are water, ordinary Portland cement, quartz sand, fly ash, water reducer and PVA fiber, and the mass ratio thereof is 1:1.25:1:1.53:0.01:0.058, wherein the water-binder ratio is 0.

36.

6. The formwork-free, high-ductility assembled composite column according to claim 1, characterized in that: Each row of truss bars includes multiple groups, and a single group of truss bars includes transverse stirrups, upper chord steel bars, lower chord steel bars and web steel bars. The stirrups are pre-cast in the outer plate, and both ends extend out of the outer plate to form hooks. After adjacent hooks overlap, reserved longitudinal bars are fixed therein; the lower chord steel bars fixed on the stirrups are fixedly connected to the upper chord steel bars through the web steel bars.

7. The formwork-free, high-ductility assembled composite column according to claim 1, characterized in that: The shell is cylindrical or prism-shaped with a regular polygonal cross section.

8. The formwork-free, high-ductility assembled composite column according to claim 7, characterized in that: When the shell is prismatic, the number of the outer panels is at least four, and the cross-section thereof is trapezoidal.

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