A solid waste-based 3D printing concrete ring-steel wire tie-lacing composite column and a manufacturing method thereof

Abstract

The application provides a solid waste-based 3D printing concrete ring steel wire tie-lacing composite column and a manufacturing method, and relates to the field of civil engineering building components. The composite column comprises a solid waste-based 3D printing concrete permanent formwork, internal cast-in-place concrete, a steel reinforcement cage and a ring steel wire tie-lacing system arranged between 3D printing strip layers. The permanent formwork is printed layer by layer along the circumference of the column to form a hollow columnar shell, and the ring steel wire tie-lacing system is arranged closed along the cross section of the column and embedded between adjacent printing strips. The ring steel wire tie-lacing system is embedded during the printing process to achieve dual effects: the tie-lacing effect connects the permanent formwork and the internal cast-in-place concrete to limit interface slip and separation; the constraint effect forms the force transmission path among the ring steel wire tie-lacing system, the permanent formwork and the internal concrete. The application also provides a manufacturing method for the composite column, which is superior to traditional reinforced concrete columns and existing 3D printing concrete columns in terms of structure, material, construction, stress, environmental protection and the like.

Description

Technical Field

[0001] This invention relates to the field of civil engineering building components technology, and more specifically, to the cross-technical field of solid waste resource utilization, 3D printing concrete permanent formwork technology and reinforced concrete composite structures. Background Technology

[0002] With the deepening of the "dual carbon" goals and the urgent need for low-carbon construction technologies in the civil engineering industry, applying industrial solid waste to 3D-printed concrete materials has become an important technological path to achieve carbon reduction and emission reduction and resource utilization in building materials. However, due to the combined effects of factors such as the layer-by-layer stacking molding method, the lack of coarse aggregate, and the weakening of interlayer interfaces, solid waste-based 3D-printed concrete still has significant deficiencies in compressive strength, ductility, and interlayer synergistic load-bearing capacity compared to traditional reinforced concrete load-bearing components. When used directly as load-bearing columns, it is difficult to fully meet the requirements for load-bearing capacity and deformation capacity.

[0003] Against this backdrop, 3D-printed concrete permanent formwork composite column technology has emerged and gradually gained attention. This technology can effectively reduce the amount and consumption of traditional formwork, improve the molding freedom of complex cross-sectional shapes, and also has certain advantages in low-carbon construction. However, existing 3D-printed permanent formwork composite columns have an unresolved key technical problem in practical applications: the external 3D-printed concrete formwork and the internal cast-in-place concrete mainly rely on interfacial bonding and geometric interlocking to achieve coordinated stress. Both are formed in stages, and the interfacial bonding strength is limited. Under axial pressure, the inner and outer concrete are prone to delamination, causing the outer formwork to be prematurely decommissioned. Once the external printed concrete formwork cracks, falls off, or partially peels off, the load-bearing capacity of the composite column will decrease significantly, exhibiting strong brittle failure characteristics, and the safety and durability of the component cannot be guaranteed.

[0004] More fundamentally, current standards for calculating the bearing capacity of concrete columns are primarily based on ordinary cast-in-place concrete columns or traditional confined concrete members. Their constraint mechanisms typically assume that the confining members (such as stirrups or steel pipes) act directly on the core concrete, creating a confinement effect. For 3D-printed concrete composite columns with permanent formwork, the external 3D-printed formwork not only participates in bearing pressure but also forms external constraints through its interface with the internal cast-in-place concrete. Simultaneously, the reinforcing wires do not act directly on the core concrete but are embedded between the layers of the 3D-printed strips, first constraining the external formwork and maintaining its integrity, and then transferring lateral constraints from the external formwork to the core concrete. However, existing theoretical frameworks lack analytical methods for this indirect constraint and synergistic mechanism of "reinforcing wires—external formwork—core concrete," making it difficult to accurately reflect the true stress characteristics and bearing capacity of composite columns. This leads to discrepancies between the bearing capacity calculated using existing formulas and the actual stress state, hindering the widespread application of such members.

[0005] In view of the above, this application is hereby submitted. Summary of the Invention

[0006] The present invention aims to provide a solid waste-based 3D printed concrete reinforced concrete composite column with steel wire tie and manufacturing method, in order to solve the shortcomings of existing solid waste-based 3D printed concrete permanent formwork composite columns, such as limited interfacial bonding strength, easy peeling of inner and outer concrete, easy detachment of outer formwork, and lack of bearing capacity calculation method.

[0007] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: A solid waste-based 3D-printed concrete reinforced composite column with wire tie rings includes: Solid waste-based 3D printed concrete permanent formwork, internal cast-in-place concrete, reinforcing cage, and wire mesh reinforcement system; The solid waste-based 3D printed concrete permanent template is a hollow columnar shell formed by printing 3D printed concrete strips layer by layer along the column circumference using a concrete 3D printer. The core pressure-bearing area formed by the internal cast-in-place concrete filling the interior of the solid waste-based 3D printed concrete permanent formwork, together with the steel cage, bears the axial pressure. The steel cage is set in the internal cast-in-place concrete and is composed of longitudinal steel bars and stirrups; The circumferential reinforcing wire tie system is embedded between adjacent 3D printed concrete strips and arranged in a closed ring along the column section. It includes an outer ring of steel wire, an inner ring of steel wire, and tie sections, forming an integrated structure with the 3D printed concrete strips. This structure provides circumferential ties and external constraints to the solid waste-based 3D printed concrete permanent template. Through the contact, interlocking, and interface synergy between the solid waste-based 3D printed concrete permanent template and the internal cast-in-place concrete, the lateral constraint effect is transferred to the internal cast-in-place concrete.

[0008] Preferably, the solid waste-based 3D printed concrete permanent template is prepared from industrial solid waste materials according to a preset design mix ratio; The industrial solid waste materials include one or more of nickel-iron slag, slag, fly ash, steel slag, and recycled micro powder as cementing materials or fine aggregate components.

[0009] Preferably, the inner ring of the reinforcing wire tie system is located in the internal cast-in-place concrete area, the outer ring of the reinforcing wire is located at the edge of the solid waste-based 3D printed concrete permanent formwork, and the tie section spans the interface between the internal cast-in-place concrete and the solid waste-based 3D printed concrete permanent formwork.

[0010] Preferably, the cross-sectional form of the solid waste-based 3D printed concrete ring-reinforced steel wire-connected composite column includes: square column, round column, or irregular column.

[0011] Preferably, when the cross-sectional shape is cylindrical, the coiled steel wire tie system is arranged in a circular closed arrangement, with the inner and outer coiled steel wires arranged in concentric circles.

[0012] Preferably, the reinforcing cage is made of longitudinal reinforcing bars and stirrups tied or welded together; The longitudinal reinforcement bars are arranged along the longitudinal direction of the column; The stirrups are fitted around the longitudinal reinforcing bars to form a cage-like structure; The reinforcing cage is placed inside the 3D-printed concrete permanent formwork on the solid waste base after the formwork is formed.

[0013] Preferably, the parameters of the ring reinforcement wire tie system include the inner ring wire side length, the outer ring wire side length, the ring reinforcement wire diameter, and the spacing of the ring reinforcement wires along the column height direction. These parameters can be adjusted according to actual engineering needs. This structure is suitable for both square columns and round columns with different cross-sectional forms.

[0014] Furthermore, the aforementioned reinforcing wire tie system plays a dual role in the composite column. The first role is tie-in: the reinforcing wire tie system, through its closed arrangement and tie sections, connects the solid waste-based 3D-printed concrete permanent formwork to the internal cast-in-place concrete, restricting interface slippage, peeling, and outer formwork detachment. The second role is constraint: during stress, the reinforcing wire tie system first restricts the lateral deformation of the solid waste-based 3D-printed concrete permanent formwork, maintaining its integrity and external constraint capacity. Then, it transmits lateral pressure from the solid waste-based 3D-printed concrete permanent formwork to the internal core concrete, improving the compressive state of the core concrete. Unlike the constraint formed by ordinary stirrups or wires directly wrapping the core concrete, the constraint in this invention is an indirect constraint and interface synergistic constraint achieved through the solid waste-based 3D-printed concrete permanent formwork, i.e., the 3D-printed outer formwork, forming a force transmission path of "reinforcing wires constraining the outer formwork—outer formwork constraining the core concrete—improved compressive performance of the core concrete."

[0015] Preferably, the axial compressive bearing capacity of the solid waste-based 3D printed concrete reinforced concrete composite column is composed of the bearing capacity of the solid waste-based 3D printed concrete permanent formwork, the internal cast-in-place concrete, and the reinforcing cage, under the combined action of the hoop and the tie constraint. The calculation process is as follows: First, the confinement effect of the solid waste-based 3D-printed concrete permanent formwork on the internal cast-in-place concrete is calculated to correct the compressive strength of the internal cast-in-place concrete. The expression for this is: ; ; ; in, This represents the compressive strength of the internal cast-in-place concrete under the action of the hoop. , The coefficient representing the influence of cross-sectional shape on the hoop effect; The hoop coefficient for permanent formwork of solid waste-based 3D printed concrete; This refers to the design value of the compressive strength of the internal cast-in-place concrete; The percentage of the cross-sectional area of ​​the 3D-printed concrete permanent formwork based on solid waste. The reduction factor for permanent formwork of solid waste-based 3D-printed concrete; The design value for the compressive strength of the permanent formwork for 3D-printed concrete based on solid waste; The total cross-sectional area of ​​the 3D-printed concrete permanent formwork based on solid waste; This refers to the cross-sectional area of ​​the internal cast-in-place concrete. The cross-sectional area of ​​the 3D-printed concrete permanent formwork based on solid waste; Then, the lateral confining pressure load caused by the tie constraint of the wire-reinforced ring system is calculated, and expressed as: ; ; ; ; ; in, This is a lateral confining pressure load; The effective constraint coefficient; It is the ratio of the volume of the transverse confinement ring reinforcement to the volume of the confinement concrete core. The yield strength of the transverse reinforcing wire; To effectively constrain the area of ​​the concrete; The area of ​​the region surrounded by the reinforcing bars; This represents the cross-sectional area of ​​a single reinforcing wire. The vertical net spacing between the reinforcing steel wires; The length of the reinforcing wire; To constrain the side length of the concrete square column; This is the distance from the center of the reinforcing wire to the edge of the column section; It is the ratio of the longitudinal reinforcement area to the core area of ​​the cross section; Next, based on the effect of the hoop, the indirect constraint strengthening of the ring reinforcement steel wire tie system is superimposed to obtain the final compressive strength of the cast-in-place concrete after confining pressure reinforcement, which is expressed as: ; in, This refers to the compressive strength of the final internal cast-in-place concrete; Finally, by integrating the bearing capacity contributions of the internal cast-in-place concrete, the solid waste-based 3D-printed concrete permanent formwork, and the longitudinal reinforcement, the axial compressive bearing capacity of the composite column with wire-reinforced ring reinforcement is calculated, and the expression is: ; in, Axial compressive bearing capacity of 3D-printed concrete ring-reinforced steel wire-connected composite columns based on solid waste; This is the stability coefficient of the reinforced concrete member; The yield strength of the longitudinal reinforcement; This represents the cross-sectional area of ​​the longitudinal reinforcing bars.

[0016] This invention also provides a method for fabricating a solid waste-based 3D-printed concrete reinforced steel wire-connected composite column, comprising: The solid waste-based 3D printed concrete permanent template is prepared by using industrial solid waste materials according to a preset design ratio; wherein, the industrial solid waste materials include one or more of nickel-iron slag, slag, fly ash, steel slag, and recycled micro powder as cementing materials or fine aggregate components. The solid waste-based 3D printed concrete permanent template is extruded layer by layer along the circumference of the column by the printing nozzle of the concrete 3D printing equipment to create 3D printed concrete strips. After printing one layer of strip, the printing equipment pauses or adjusts the nozzle position, and the reinforcing wire tie system is placed flat on the surface of that layer of strip. Then, the next layer of strip is printed, so that the reinforcing wire tie system is wrapped between the two adjacent printed strips, forming a hollow outer template that shares the force with the printed layers. The reinforcing wire tie system includes an outer ring of steel wire, an inner ring of steel wire, and tie sections. After printing is completed, a reinforcing cage is installed inside the permanent formwork of the solid waste-based 3D printed concrete; the reinforcing cage consists of longitudinal reinforcing bars and stirrups; Concrete is poured into the interior of the solid waste-based 3D-printed concrete permanent template and vibrated to form the internal cast-in-place concrete. After vibration, smooth the surface of the column top and cover it with plastic film or water it for curing. After curing, a composite column of solid waste-based 3D printed concrete ring reinforcement steel wire is formed. During the curing period, the strength of the permanent formwork of solid waste-based 3D printed concrete and the internal cast-in-place concrete gradually increases. The two form a whole and share the force through the interface bonding and the tie effect of the ring reinforcement steel wire tie system.

[0017] Preferably, before placing the reinforcing wire tie system flat onto the surface of the printing strip, the surface of the reinforcing wire tie system is roughened in advance. Taking advantage of the plasticity of the 3D printed concrete strip after extrusion and the self-compacting interlocking effect of the upper and lower adjacent 3D printed concrete strips after the reinforcing wire is placed, the surface roughened reinforcing wire tie system is placed flat on the current printing strip surface, and then the printing and extrusion of the next layer of 3D concrete strip is carried out to improve the interfacial bonding strength and anti-slip ability between the reinforcing wire and the printed concrete strip.

[0018] Preferably, the outer ring wire, inner ring wire, or tie section of the reinforcing wire tie system is provided with a spiral structure, which is embedded inside the 3D printed concrete strip to form a mechanical interlocking anchor with the printed layer.

[0019] In summary, compared with the prior art, the present invention has the following beneficial effects: This invention constructs a stable mechanical connection path between the inner and outer concrete by embedding a ring reinforcement steel wire tie system between the layers of 3D printed concrete strips. This can significantly inhibit interface peeling and premature detachment of the permanent formwork (outer formwork) of solid waste-based 3D printed concrete, and enhance the collaborative working ability between the outer formwork and the internal cast-in-place concrete.

[0020] The steel wire tie system of the present invention has the functions of interlayer embedding, interface tying and external formwork constraint. Its constraint effect does not act directly on the core concrete, but improves the integrity and anti-bulging ability of the 3D printed external formwork, so that the external formwork continuously participates in the lateral constraint of the internal cast-in-place concrete, thereby forming an indirect constraint system that is different from the conventional stirrup-constrained concrete, effectively improving the axial compressive bearing capacity, ductility and interface collaborative working ability of the composite column.

[0021] The technical solution of this invention is applicable to composite columns with different cross-sectional forms, and has good applicability to both square and round columns. The steel wire arrangement parameters are adjustable and can be optimized according to actual engineering needs.

[0022] This invention integrates the utilization of solid waste materials, 3D printing permanent template technology, and the construction of a steel wire tie structure. While achieving green and low-carbon construction, it improves the shortcomings of solid waste 3D printed concrete in terms of mechanical properties and interlayer integrity. By embedding the steel wire tie system between the printed strip layers, the integrity and deformation resistance of the outer template are effectively enhanced, and the synergistic stress performance between the outer template and the internal cast-in-place concrete is further improved. Thus, the efficient utilization of solid waste materials is achieved while ensuring structural performance.

[0023] The bearing capacity calculation formula proposed in this invention takes into account the confinement effect of the outer formwork on the internal cast-in-place concrete and the binding constraint effect of the steel wire tie system. It can accurately reflect the collaborative stress characteristics of the steel wire tie composite column. The formula has wide applicability and can be extended to the bearing capacity prediction of various permanent formwork composite columns and steel wire confined concrete columns, providing theoretical support for engineering design. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a structural breakdown diagram of the solid waste-based 3D-printed concrete ring-reinforced steel wire-connected composite column provided in Example 1.

[0026] Figure 2 The diagram shows the core area of ​​the coiled steel wire calculation provided in Example 1, including the longitudinal section AA and the transverse section BB.

[0027] Figure descriptions: 1: 3D-printed permanent formwork for solid waste-based concrete; 2: Internal cast-in-place concrete; 3: Reinforcing cage; 4: Wire mesh reinforcement system; 5: Outer wire mesh; 6: Inner wire mesh; 7: Tie section; 11: Effective core zone I of cast-in-place concrete; 12: Effective confined transition zone II of cast-in-place concrete; 13: Effective zone III of 3D printed concrete; 14: Ineffective zone IV of 3D printed concrete; AA: Longitudinal section view; BB: Transverse section view.

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0030] Example 1 like Figure 1 As shown, a solid waste-based 3D printed concrete composite column with ring reinforcement and steel wire tie is provided, comprising: a solid waste-based 3D printed concrete permanent formwork 1, an internal cast-in-place concrete 2, a reinforcing cage 3, and a ring reinforcement and steel wire tie system 4.

[0031] The solid waste-based 3D printed concrete permanent template 1 is a hollow columnar shell formed by printing 3D printed concrete strips layer by layer along the circumference of the column by a concrete 3D printer.

[0032] In a specific embodiment, the solid waste-based 3D-printed concrete permanent template 1 is prepared from industrial solid waste materials according to a preset design ratio. The industrial solid waste materials include one or more of nickel-iron slag, slag, fly ash, steel slag, and recycled micro powder as cementing materials or fine aggregate components.

[0033] Taking 3D-printed nickel-iron slag concrete as a permanent formwork material for solid waste-based 3D-printed concrete as an example, the mix design controls the amount of industrial solid waste to be 20% to 50% of the total mass of cementitious materials. By adjusting the ratio of nickel-iron slag to slag, the fluidity and early strength of the 3D-printed slurry can be effectively controlled. For example, nickel-iron slag accounts for 15-30% of the total mass of cementitious materials, slag accounts for 15-30% of the total mass of cementitious materials, silica fume accounts for 0-10% of the total mass of cementitious materials, and the water-cement ratio is controlled at 0.30-0.40.

[0034] In a preferred embodiment, a mix proportion of 15% nickel-iron slag, 15% slag, 10% silica fume, and 60% cement can be used, with a mortar-to-bond ratio of 1:1.5 and a water-to-binder ratio of 0.35. The resulting 3D printed concrete must meet the requirements for printing extrusion and constructability.

[0035] The internal cast-in-place concrete 2 fills the core pressure-bearing area formed inside the solid waste-based 3D printed concrete permanent formwork 1, and together with the steel cage 3, it bears the axial pressure.

[0036] The steel cage 3 is set in the internal cast-in-place concrete 2 and is composed of longitudinal steel bars and stirrups.

[0037] The reinforcing cage 3 is formed by binding or welding longitudinal reinforcing bars and stirrups. The longitudinal reinforcing bars are arranged along the longitudinal direction of the column; the stirrups are sleeved around the longitudinal reinforcing bars to form a cage-like structure.

[0038] The number and diameter of longitudinal steel bars can be determined according to the bearing capacity design requirements of the composite column. Usually, 4 to 8 HRB400 or HRB500 grade steel bars with a diameter of 12mm to 25mm are used. The stirrups are HPB300 or HRB400 grade steel bars with a diameter of 6mm to 10mm. The stirrup spacing is set to 50mm to 200mm according to the shear resistance and restraint requirements.

[0039] The reinforcing cage 3 is placed inside the 3D-printed concrete permanent formwork 1 after it has been formed. At this point, the 3D-printed concrete permanent formwork 1 has a certain strength and can withstand the self-weight of the reinforcing cage 3 and the construction load.

[0040] The ring-shaped steel wire tie system 4 is embedded between adjacent 3D printed concrete strips and arranged in a closed ring along the column section. It includes an outer ring steel wire 5, an inner ring steel wire 6, and a tie section 7, forming an integrated structure with the 3D printed concrete strips to form a circumferential tie and external constraint on the solid waste-based 3D printed concrete permanent template 1. Through the contact, interlocking, and interface synergy between the solid waste-based 3D printed concrete permanent template 1 and the internal cast-in-place concrete 2, the lateral constraint effect is transferred to the internal cast-in-place concrete 2.

[0041] The inner ring steel wire 6 of the ring steel wire tie system 4 is located in the area of ​​the internal cast-in-place concrete 2, the outer ring steel wire 5 is located at the edge of the solid waste-based 3D printed concrete permanent template 1, and the tie section 7 spans the interface between the internal cast-in-place concrete 2 and the solid waste-based 3D printed concrete permanent template 1.

[0042] During the printing process, 3D-printed concrete containing solid waste is extruded layer by layer along the circumference of the column through the printing nozzle of the concrete 3D printer. Before each printed strip solidifies, a reinforcing wire tie system 4 is embedded. Then, the next strip is printed, so that the reinforcing wire tie system 4 is wrapped between adjacent printed strips, forming a composite structure that shares the load with the printed layers. The parameters of the reinforcing wire tie system 4 include the side length of the inner and outer wires, the diameter of the reinforcing wires, and the vertical net spacing between the reinforcing wires along the column height. These parameters can be adjusted according to actual engineering needs to balance the tie effect and the enclosure effect. This structure is suitable for square columns, as well as round columns, irregularly shaped columns, and other cross-sectional forms. When the cross-sectional form is a round column, the reinforcing wire tie system is arranged in a closed circular pattern, with the inner and outer wires arranged in concentric circles.

[0043] In one optional embodiment, during the printing of the solid waste-based 3D-printed concrete permanent template 1, the outer ring steel wire 5, inner ring steel wire 6, and tie section 7 of the reinforcing wire tie system 4 are pre-treated with surface roughening. This can be achieved by mechanical sandblasting, roller texturing, or physical wire drawing processes to increase the micro-roughness of the outer surface of the steel wires. During the 3D printing process, the concrete printing nozzle extrudes 3D-printed concrete strips layer by layer along the circumference of the column. After each layer is extruded, the printed concrete is still in a state of not being initially set and possessing good plasticity. The surface-roughened reinforcing wire tie system 4 is then placed smoothly on the surface of the current printing strip, and the printing and extrusion of the next layer of 3D concrete strip begins. The newly extruded concrete mixture in the upper layer has good fluidity and strong self-compacting properties. Under the action of its own weight and printing extrusion force, it automatically adheres to and wraps the outer surface of the steel wire. The unhardened concrete in the lower layer also undergoes plastic deformation as the steel wire is pressed in, closely adhering to the outline of the steel wire. Relying on the self-compacting interlocking effect of the adjacent 3D printed concrete strips, the roughened steel wire is completely wrapped and embedded between the two printed layers.

[0044] This embodiment does not change the original 3D printing continuous construction process, nor disturb the unhardened plastic concrete strip. By increasing the surface roughness of the steel wire itself, combined with the self-compacting wrapping effect between the printed concrete layers, it effectively improves the interfacial bonding strength and anti-slip ability between the reinforcing steel wire and the 3D printed concrete strip, preventing the steel wire from loosening or slipping under stress, and ensuring a stable and reliable circumferential tie constraint effect on the 3D printed concrete permanent template 1 based on solid waste.

[0045] During the wire processing and forming, the spiral reinforcement wire tie system 4 can be equipped with a spiral structure on the outer ring wire 5, inner ring wire 6, or tie section 7, maintaining the overall closed loop arrangement of the reinforcement wires and forming a continuous spiral undulating profile only along the length of the wires themselves. During 3D printing, solid waste-based 3D printed concrete strips are extruded layer by layer. Once a single layer is extruded and still in a plastic, unhardened state, the spiral reinforcement wire tie system 4 is directly laid flat on the surface of the current printed layer, and then the next layer of concrete strip is immediately printed. The spiral wires, relying on their spiral shape, can naturally and slightly embed themselves into the surface of the lower plastic concrete strip; simultaneously, the newly extruded concrete slurry can fully fill and self-compact along the pitch gaps of the spiral wires, ensuring the spiral wires are completely wrapped, embedded, and anchored by the upper and lower printed concrete layers, forming a continuous and reliable mechanical interlocking effect.

[0046] This embodiment is adapted to the process characteristics of 3D printing, which allows for real-time reinforcement and continuous molding. The spiral configuration significantly increases the contact area between the steel wire and the concrete and the mechanical interlocking effect, further strengthening the overall anchoring performance of the reinforcing steel wire and the printed layer. This effectively limits the relative slippage between layers and the outward deformation of the template, improving the overall stress coordination and structural integrity of the composite column.

[0047] The axial compressive bearing capacity of the solid waste-based 3D printed concrete ring-reinforced steel wire-connected composite column is composed of the bearing capacity of the solid waste-based 3D printed concrete permanent formwork 1, the internal cast-in-place concrete 2, and the steel cage 3, and is formed under the combined action of the hoop and the tie constraint.

[0048] During the stress process, the solid waste-based 3D-printed concrete permanent formwork 1 initially shares the axial pressure with the internal cast-in-place concrete 2. When the internal cast-in-place concrete 2 exhibits a tendency to expand laterally under pressure and a tendency for relative slippage occurs at the interface, the ring-shaped steel wire tie system 4 embedded between the printed strip layers delays the separation of the solid waste-based 3D-printed concrete permanent formwork 1 from the internal cast-in-place concrete 2 by tying them together, and restrains the lateral outward deformation of the solid waste-based 3D-printed concrete permanent formwork 1 by closing the steel wire rings. As the load continues to increase, the ring-shaped steel wire tie system 4 does not directly form a traditional arch-shaped constraint on the internal cast-in-place concrete 2, but first forms a circumferential constraint on the solid waste-based 3D-printed concrete permanent formwork 1, and then the solid waste-based 3D-printed concrete permanent formwork 1 transmits lateral pressure to the internal cast-in-place concrete 2, placing the internal cast-in-place concrete 2 in a more favorable compressive state. Thus, the component forms a multi-level collaborative stress mechanism of "steel wire tie - solid waste-based 3D-printed concrete permanent formwork constraint - internal cast-in-place concrete constraint", thereby improving the overall bearing capacity, ductility and failure stability of the composite column.

[0049] Specifically, the calculation process for the axial compressive bearing capacity of the solid waste-based 3D-printed concrete reinforced steel wire-connected composite column is as follows: First, the constricting effect of the solid waste-based 3D-printed concrete permanent formwork 1 on the internal cast-in-place concrete 2 is calculated to correct the compressive strength of the internal cast-in-place concrete 2. The expression is as follows: ; ; ; in, The compressive strength value of the internal cast-in-place concrete under the action of the hoop; , The coefficients representing the influence of cross-sectional shape on the hoop effect are as follows: for a square column, B = 0.15 and C = 0.025; for a cylindrical column, B = 0.20 and C = 0.030. The hoop coefficient for the 3D-printed concrete permanent formwork 1 based on solid waste; The design value for the compressive strength of the internal cast-in-place concrete 2; The cross-sectional area percentage of the solid waste-based 3D printed concrete permanent formwork 1; The reduction factor for the 3D-printed concrete permanent formwork 1 based on solid waste; The design value of compressive strength for 3D-printed concrete permanent formwork 1 based on solid waste; The total cross-sectional area of ​​the 3D-printed concrete permanent formwork 1 based on solid waste; The cross-sectional area of ​​the internal cast-in-place concrete 2; The cross-sectional area of ​​the solid waste-based 3D printed concrete permanent formwork 1 is shown.

[0050] Then, the lateral confining pressure load caused by the tie constraint of the 4-link steel wire tie system is calculated, which is expressed as: ; ; ; ; ; in, This is a lateral confining pressure load; The effective constraint coefficient; It is the ratio of the volume of the transverse confinement ring reinforcement to the volume of the confinement concrete core. The yield strength of the transverse reinforcing wire; To effectively constrain the area of ​​the concrete; The area of ​​the region surrounded by the reinforcing bars; This represents the cross-sectional area of ​​a single reinforcing wire. The vertical net spacing between the reinforcing steel wires; The length of the reinforcing wire; To constrain the side length of the concrete square column; This is the distance from the center of the reinforcing wire to the edge of the column section; It is the ratio of the longitudinal reinforcement area to the core area of ​​the cross section.

[0051] Next, based on the effect of the hoop reinforcement, the indirect confinement strengthening with the addition of reinforcing steel wires is used to obtain the compressive strength of the final cast-in-place concrete after confining pressure reinforcement, expressed as: ; in, This refers to the compressive strength of the final internal cast-in-place concrete.

[0052] Finally, by integrating the bearing capacity contributions of the internal cast-in-place concrete 2, the solid waste-based 3D-printed concrete permanent formwork 1, and the longitudinal reinforcement, the axial compressive bearing capacity of the composite column with wire-reinforced ring reinforcement is calculated, and the expression is: ; in, Axial compressive bearing capacity of 3D-printed concrete ring-reinforced steel wire-connected composite columns based on solid waste; The stability coefficient of the reinforced concrete member is determined according to the slenderness ratio of the member in accordance with the "Code for Design of Concrete Structures" GB 50010. The cross-sectional area of ​​the internal cast-in-place concrete 2; Let be the reduction factor for the 3D-printed concrete permanent formwork 1 based on solid waste, such as assuming ; The design value of compressive strength for 3D-printed concrete permanent formwork 1 based on solid waste; The cross-sectional area of ​​the 3D-printed concrete permanent formwork 1 based on solid waste; The yield strength of the longitudinal reinforcement; This represents the cross-sectional area of ​​the longitudinal reinforcing bars.

[0053] This calculation method considers two aspects: the hoop effect of the solid waste-based 3D-printed concrete permanent formwork 1 and the tie-restrain effect of the reinforcing steel wire system 4. When considering the hoop effect of the solid waste-based 3D-printed concrete permanent formwork 1, the strength of the reinforced concrete in the hoop is used instead of the strength of the core area concrete to reflect the improvement effect of the hoop restraint of the solid waste-based 3D-printed concrete permanent formwork 1 on the load-bearing performance of the component.

[0054] When considering the binding and restraining effect of the reinforcing wire tie system 4, unlike ordinary confined concrete where stirrups or wires directly act on the core concrete to form a fixed arched restraint zone, the restraining effect generated by the reinforcing wire tie system 4 in this invention is first transferred to the 3D-printed concrete outer formwork, the solid waste-based 3D-printed concrete permanent formwork 1, and then the solid waste-based 3D-printed concrete permanent formwork 1 applies indirect lateral restraint to the internal cast-in-place concrete 2. Its effective restraint area is not simply determined by the geometric position of the wires, but is jointly controlled by the reinforcing wire tie system 4, the solid waste-based 3D-printed concrete permanent formwork 1, and the interface between the inner and outer concrete.

[0055] Furthermore, this invention establishes a stress-strain constitutive model for confined concrete to describe the compressive mechanical behavior of the internal cast-in-place concrete 2 under the combined action of the reinforcing wire tie system 4 and the solid waste-based 3D printed concrete permanent formwork 1, providing a theoretical basis for the analysis of the stress performance and calculation of the bearing capacity of the component.

[0056] The model characterizes the relationship between axial stress and strain in confined concrete using the following formula: ; ; ; ; ; in, This refers to the axial stress in the concrete. To constrain the compressive strength of concrete; Strain ratio; These are parameters related to the elastic modulus; This represents the axial strain of the concrete. To constrain the strain of concrete under compressive strength; The strain of unconfined concrete under compressive strength; This refers to the compressive strength of unconfined concrete. This refers to the elastic modulus of concrete. To constrain the secant modulus of concrete.

[0057] This model reveals the stress-strain development law of concrete under constraint, providing a theoretical basis for the ductility, stiffness and nonlinear stress analysis of components; the bearing capacity calculation formula is based on the final result of the constraint effect, and gives the ultimate bearing capacity expression for engineering design. Together, they constitute the complete mechanical theory system of this invention.

[0058] In this invention, reinforcing wires are embedded between adjacent 3D-printed concrete strips at intervals along the column height. Arranged in a closed ring, the solid waste-based 3D printed concrete permanent formwork 1 maintains its integrity through mechanical ties and constraints, avoiding interlayer peeling and external bulging cracks.

[0059] When the column is subjected to axial pressure, the internal cast-in-place concrete 2 tends to expand laterally under pressure, exerting radial outward compressive force on the inner wall of the solid waste-based 3D-printed concrete permanent formwork 1, which can easily lead to interlayer separation and outward bulging cracking of the formwork. The ring reinforcement wire tie system balances this compressive force through the following mechanism: Yield tensile strength of a single reinforcing wire for: ; in, This represents the cross-sectional area of ​​a single reinforcing wire. This represents the yield strength of the transverse reinforcing wire.

[0060] The equivalent circumferential restraint stress provided by the reinforcing wire (Applied to the inner wall of the 3D-printed concrete permanent formwork 1 based on solid waste) is: ; in, The length of the reinforcing wire is the side length. This refers to the vertical net spacing between the reinforcing steel wires.

[0061] Mechanical conditions under which the template layers do not separate: ; in, For extrusion pressure, This refers to the wall thickness of the permanent template.

[0062] When this condition is met, the permanent formwork always maintains an overall stress state, without interlayer peeling or outward bulging and cracking, thereby maintaining the confinement effect on the internal cast-in-place concrete 2.

[0063] The stress process of the solid waste-based 3D-printed concrete permanent formwork 1 can be divided into two stages, and the role transition has a clear critical load condition: Joint bearing stage (low load): The axial compression load is jointly borne by the solid waste-based 3D printed concrete permanent formwork 1 and the internal cast-in-place concrete 2 according to the stiffness ratio. At this time, the formwork mainly participates in the work as a compression member; the lateral expansion of the internal cast-in-place concrete 2 is very small, and the radial compressive force on the solid waste-based 3D printed concrete permanent formwork 1 can be ignored, and the hoop effect has not yet been activated.

[0064] Constraint-dominated stage (high load): When the load increases to the critical value, the internal cast-in-place concrete 2 enters the plastic stage, and the lateral expansion is significant. The radial compressive force generated on the solid waste base 3D printed concrete permanent formwork 1 exceeds the unconstrained circumferential tensile capacity of the formwork itself. Under the tie action of the ring reinforcement wire, the formwork changes from a "simple compression member" to a "tension-constrained member". The hoop effect begins to dominate, and the lateral constraint pressure increases synchronously with the load.

[0065] The critical load for the transformation of the role of solid waste-based 3D-printed concrete permanent formwork 1 is defined as the axial compressive load when the radial compressive force generated by the core concrete is equal to the ultimate circumferential tensile capacity of the formwork without reinforcing bars: Ultimate circumferential tensile strength of formwork without ring reinforcement for: ; in, For the tensile strength of 3D printed concrete, This refers to the wall thickness of the permanent template.

[0066] Corresponding critical radial extrusion pressure for: ; The critical axial compressive stress of the core concrete when this radial compressive force is generated. (i.e., stress at the role transition point): ; in, The Poisson's ratio of concrete. This represents the design value of the compressive strength of the internal cast-in-place concrete 2. When the axial compressive stress of the column... At that time, the role of the 3D-printed concrete permanent formwork 1 based on solid waste changed from "compression" to "constraint", and the hoop effect began to dominate the stress, providing a lateral constraint foundation for the subsequent improvement of the core concrete strength.

[0067] In one specific embodiment, for a composite column with a cylindrical cross-section, the closed-loop arrangement of the reinforcing wire tie system 4 is adjusted to a circle, with the inner and outer rings of wire arranged concentrically, and the tie section 7 extending radially to connect the inner and outer rings. The side length of the confined concrete square column with a cylindrical cross-section... The diameter of the cylinder is replaced with the cylindrical shape, while other calculation formulas remain unchanged. The cylindrical solid waste-based 3D-printed concrete permanent formwork 1 is formed layer by layer along a spiral path using a 3D printer, with a circular reinforcing wire tie system 4 embedded during the printing process. This structure also achieves the dual function of tying and restraining the inner and outer concrete through the reinforcing wire tie system 4, and the bearing capacity calculation method can be extended to cylindrical sections.

[0068] like Figure 2The AA cross-sectional view shown illustrates the vertical net spacing between the reinforcing wires along the column height. , confined concrete square column side length Length of the reinforcing wire Key dimensional parameters are shown, and the effective and ineffective constraint areas are marked, including the cast-in-place concrete core effective area I (11), the cast-in-place concrete constraint transition effective area II (12), the 3D printed concrete effective area III (13), and the ineffective area IV (14). The arrows in the figure clearly show the indirect constraint force transmission path of "reinforcing wire - 3D printed outer formwork - core concrete". The BB section diagram uses different colors and area markings to show the positional relationship of the core effective area, ineffective area, and reinforcing wire tie system 4, intuitively presenting the dual action mechanism of reinforcing wire tie system 4 in tying and constraining the inner and outer concrete, and clarifying the embedded position of reinforcing wire tie system 4 at the interface between the inner cast-in-place concrete 2 and the 3D solid waste base 3D printed concrete permanent formwork 1.

[0069] The indirect constraint path of this invention differs fundamentally from the traditional direct constraint mechanism of stirrups / steel wires directly constraining the core concrete. A detailed comparative analysis is as follows: (1) Constraint transmission path The indirect constraints of this invention are: the use of a steel wire tie system → outer formwork → core concrete; Traditional direct restraint: using stirrups / steel wire → core concrete.

[0070] (2) Constraint objects The indirect constraint of this invention is achieved by first constraining the outer template, and then passing the constraint through the outer template. Traditional direct constraint: Directly constrain the core concrete.

[0071] (3) Sources of constraint stress The indirect constraint of this invention: the circumferential constraint is generated by the tension of the steel wire tie system, and the lateral pressure is applied to the core concrete by the outer formwork; Traditional direct restraint: Stirrups / steel wires are under tension, directly generating lateral pressure on the core concrete.

[0072] (4) Constraint stress distribution The indirect constraint of this invention is transmitted through the interface contact and interlocking between the outer formwork and the core concrete, resulting in uniform distribution and no obvious local stress concentration. Traditional direct constraint: stress concentration only occurs at the location of stirrups / wires, resulting in an unconstrained "arch effect zone".

[0073] (5) Stability of constraints The indirect constraint of this invention is that the steel wire tie system is wrapped and protected by the outer template, making it less prone to corrosion and failure, and the hoop effect remains stable. Traditional direct constraint: once the stirrups / wires yield or corrode, the constraint fails directly.

[0074] (6) The persistence of the hoop effect The indirect constraint of this invention is that the steel wire tie system maintains the integrity of the template, and the hoop effect persists from low load to ultimate load. Traditional direct constraint: The effect of the stirrups decays rapidly after the stirrups yield.

[0075] (7) The mode of action of the core concrete The indirect constraint of this invention: the template provides uniform constraint on the core concrete, making the core concrete more uniformly under triaxial compression. Traditional direct restraint: local restraint by stirrups / wires, forming only a partial triaxial compression zone between stirrups.

[0076] In summary, compared with the prior art, the present invention constructs a stable mechanical connection path between the inner and outer concrete by embedding a ring reinforcement steel wire tie system 4 between the layers of 3D printed concrete strips. This can significantly suppress interface peeling and premature detachment of the outer formwork, and enhance the collaborative working ability between the solid waste-based 3D printed concrete permanent formwork 1 and the internal cast-in-place concrete 2.

[0077] The steel wire tie system 4 has the functions of interlayer embedding, interface tying and external formwork constraint. Its constraint effect does not directly act on the core concrete, but improves the integrity and anti-bulging ability of the 3D printed solid waste-based 3D printed concrete permanent formwork 1, so that the solid waste-based 3D printed concrete permanent formwork 1 continuously participates in the lateral constraint of the internal cast-in-place concrete 2, thus forming an indirect constraint system that is different from the conventional stirrup-constrained concrete, effectively improving the axial compressive bearing capacity, ductility and interface collaborative working ability of the composite column.

[0078] The technical solution of this invention is applicable to composite columns with different cross-sectional forms, and has good applicability to both square and round columns. The steel wire arrangement parameters are adjustable and can be optimized according to actual engineering needs.

[0079] Example 2 The second embodiment of the present invention also provides a method for fabricating a solid waste-based 3D-printed concrete reinforced steel wire-connected composite column as described above, comprising: Step 1: Prepare the solid waste-based 3D printed concrete permanent template 1 by mixing industrial solid waste materials according to the preset design ratio; wherein, the industrial solid waste materials include one or more of nickel-iron slag, slag, fly ash, steel slag, and recycled micro powder as cementing materials or fine aggregate components.

[0080] Simultaneously, its fluidity, extrudability, constructability, and early strength can be adjusted according to printing requirements. Specifically, the slump spread of 3D printed concrete can be controlled between 160mm and 180mm, and its plastic viscosity can be controlled within the range of 50Pa·s to 100Pa·s to meet the requirements of smooth extrusion from the printing nozzle and layer-by-layer stacking. Regarding early strength, the early strength of the printing material must be sufficient to ensure that the formed layers can withstand the weight of the layers above without significant deformation during the printing process.

[0081] Step 2: The solid waste-based 3D printed concrete permanent template 1 is extruded layer by layer along the circumference of the column through the printing nozzle of the concrete 3D printing equipment to form 3D printed concrete strips.

[0082] During printing, the print head of the concrete 3D printer runs along a preset path, continuously extruding 3D printed concrete material to form annular strips. The width of each strip is typically 20mm to 30mm, and the height is 10mm to 20mm.

[0083] Step 3: After printing one layer of strip, the printing equipment pauses or the nozzle position is adjusted. The (pre-bent) coiled steel wire tie system 4 is placed flat on the surface of the strip at a preset interval. Then, the next layer of strip is printed so that the coiled steel wire tie system 4 is wrapped between the two adjacent printed strips, forming a hollow outer template that shares the force with the printed layer. The coiled steel wire tie system includes an outer steel wire 5, an inner steel wire 6, and a tie section 7.

[0084] The vertical net spacing between the reinforcing wires in the ring reinforcement system 4 along the column height is set according to design requirements, typically 50mm to 100mm. The vertical distance between adjacent layers of the ring reinforcement system 4 remains uniform. The closed ring arrangement of the ring reinforcement system 4 places its inner ring in the core concrete area and its outer ring at the edge of the solid waste-based 3D printed concrete permanent formwork 1. The tie section 7 spans the interface between the inner and outer concrete, connecting the solid waste-based 3D printed concrete permanent formwork 1 to the internal cast-in-place concrete 2 as a whole.

[0085] Step 4: After printing is completed, install the steel cage 3 inside the 3D printed concrete permanent template 1 based on solid waste; the steel cage 3 is composed of longitudinal steel bars and stirrups.

[0086] After the reinforcing cage 3 is tied or welded on the ground, it is hoisted and positioned inside the 3D-printed concrete permanent formwork 1. A certain gap, typically 10mm to 30mm, is left between the outer surface of the reinforcing cage 3 and the inner surface of the 3D-printed concrete permanent formwork 1 to ensure that the cast-in-place concrete 2 inside can fully fill and enclose the reinforcing cage 3. The reinforcing cage 3 is positioned and fixed by temporary support devices or spacers to ensure that it does not shift during the pouring process.

[0087] Step 5: Pour internal cast-in-place concrete into the interior of the solid waste-based 3D printed concrete permanent template 1 and vibrate it to form internal cast-in-place concrete 2; Step 6: After vibration, smooth the surface of the column top and cover it with plastic film or water it for curing.

[0088] The internal cast-in-place concrete 2 is typically made of ordinary Portland cement concrete with a strength grade of not less than C30. The slump is controlled between 180mm and 220mm to ensure good fluidity. During pouring, it is poured in from the opening at the top of the column and compacted in sections along the column height using an immersion vibrator. The vibration interval is no more than 1.5 times the radius of action of the vibrator, ensuring that the internal cast-in-place concrete 2 is densely packed and in full contact with the inner wall of the 3D-printed concrete permanent formwork 1. After vibration, the surface of the column top is smoothed and covered with plastic film or watered for curing.

[0089] Step 7: After curing, a solid waste-based 3D printed concrete composite column with reinforcing steel wire is formed. During the curing period, the strength of the solid waste-based 3D printed concrete permanent formwork 1 and the internal cast-in-place concrete 2 gradually increases. The two form a whole and share the force through the interface bonding and the tying effect of the reinforcing steel wire system.

[0090] Under natural curing conditions, the composite column can be put into use after a curing period of no less than 28 days. During the curing period, the strength of the solid waste-based 3D printed concrete permanent formwork 1 and the internal cast-in-place concrete 2 gradually increases, and the two form a whole to share the load through the bonding effect of the interface and the tie-bar steel wire system 4.

[0091] In this embodiment of the invention, the ring-reinforced steel wire tie system 4 performs a dual function. The first function is tie connection: the ring-reinforced steel wire tie system 4, through its closed arrangement and tie section 7, connects the solid waste-based 3D-printed concrete permanent formwork 1 to the internal cast-in-place concrete 2 as a whole, restricting interface slippage, peeling, and outer formwork detachment. Specifically, the tie section 7 of the ring-reinforced steel wire tie system 4 spans the interface area between the solid waste-based 3D-printed concrete permanent formwork 1 and the core concrete. When the inner and outer concrete tend to slip relative to each other due to shrinkage differences or uneven stress, the tie section 7 bears the tensile force and transmits the force to the annular portion of the solid waste-based 3D-printed concrete permanent formwork 1 and the core concrete, thereby inhibiting interface separation. The closed ring structure formed by the outer steel wire 5 and the inner steel wire 6 allows the tensile force to be evenly distributed along the circumference, avoiding localized damage caused by stress concentration.

[0092] In this embodiment, the solid waste-based 3D-printed concrete permanent formwork 1 uses industrial solid wastes such as nickel-iron slag, slag, fly ash, steel slag, and recycled micro powder as cementitious materials or fine aggregates to replace cement and natural aggregates, reducing resource consumption and carbon emissions, which aligns with the dual-carbon goals and the development direction of green building materials. Preparing solid waste-based 3D-printed concrete according to a preset mix proportion ensures the printability, early strength, and long-term mechanical properties of the material, achieving high-value and large-scale utilization of solid waste, thus combining environmental and economic benefits.

[0093] This invention achieves comprehensive technical advantages through the organic combination of a solid waste-based 3D-printed permanent template 1, internal cast-in-place concrete 2, a reinforcing cage 3, and a ring reinforcement wire tie system 4. It features no need for formwork removal, solid waste resource utilization, strong interface synergy, multi-level constraints, high load-bearing capacity, high ductility, and convenient construction. It is superior to traditional reinforced concrete columns and existing 3D-printed concrete columns in terms of structure, materials, construction, stress, and environmental protection, and has extremely high engineering application value and promotion prospects.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A solid waste-based 3D-printed concrete reinforced steel wire-connected composite column, characterized in that, include: Solid waste-based 3D printed concrete permanent formwork, internal cast-in-place concrete, reinforcing cage, and wire mesh reinforcement system; The solid waste-based 3D printed concrete permanent template is a hollow columnar shell formed by printing 3D printed concrete strips layer by layer along the column circumference using a concrete 3D printer. The core pressure-bearing area formed by the internal cast-in-place concrete filling the interior of the solid waste-based 3D printed concrete permanent formwork, together with the steel cage, bears the axial pressure. The steel cage is set in the internal cast-in-place concrete and is composed of longitudinal steel bars and stirrups; The reinforcing wire tie system is embedded between adjacent 3D-printed concrete strips, arranged in a closed ring along the column cross-section. It includes an outer ring of steel wires, an inner ring of steel wires, and tie sections, forming an integrated structure with the 3D-printed concrete strips. This structure provides circumferential ties and external constraints to the solid waste-based 3D-printed concrete permanent template. Through the contact, interlocking, and interface synergy between the solid waste-based 3D-printed concrete permanent template and the internal cast-in-place concrete, the lateral constraint effect is transferred to the internal cast-in-place concrete. Specifically, the inner ring of the reinforcing wire tie system is located in the internal cast-in-place concrete area, the outer ring of steel wires is located at the edge of the solid waste-based 3D-printed concrete permanent template, and the tie sections span the interface between the internal cast-in-place concrete and the solid waste-based 3D-printed concrete permanent template. The axial compressive bearing capacity of the solid waste-based 3D-printed concrete reinforced concrete composite column is composed of the bearing capacity of the solid waste-based 3D-printed concrete permanent formwork, the internal cast-in-place concrete, and the reinforcing cage, under the combined action of the hoop and the tie constraint. The calculation process is as follows: First, the confinement effect of the solid waste-based 3D printed concrete permanent formwork on the internal cast-in-place concrete is calculated to correct the compressive strength of the internal cast-in-place concrete. Then calculate the lateral confining pressure load caused by the tie constraint of the wire mesh reinforcement system; Next, based on the effect of the hoop, the indirect constraint reinforcement of the ring reinforcement steel wire tie system is superimposed to obtain the final compressive strength of the internal cast-in-place concrete after confining pressure reinforcement. Finally, by integrating the bearing capacity contributions of the internal cast-in-place concrete, the solid waste-based 3D-printed concrete permanent formwork, and the longitudinal reinforcement, the axial compressive bearing capacity of the composite column with wire mesh reinforcement was calculated.

2. The solid waste-based 3D printed concrete ring-reinforced steel wire-connected composite column according to claim 1, characterized in that, The solid waste-based 3D printed concrete permanent template is prepared from industrial solid waste materials according to a preset design ratio; The industrial solid waste materials include one or more of nickel-iron slag, slag, fly ash, steel slag, and recycled micro powder as cementing materials or fine aggregate components.

3. The solid waste-based 3D printed concrete ring-reinforced steel wire-connected composite column according to claim 1, characterized in that, The cross-sectional forms of the solid waste-based 3D printed concrete ring-reinforced steel wire-connected composite column include: square column, round column, or irregular column.

4. A solid waste-based 3D-printed concrete ring-reinforced steel wire-connected composite column according to claim 3, characterized in that, When the cross-section is cylindrical, the ring-shaped steel wire tie system is arranged in a circular closed arrangement, with the inner and outer ring steel wires arranged in concentric circles.

5. A solid waste-based 3D-printed concrete ring-reinforced steel wire-connected composite column according to claim 1, characterized in that, The steel cage is made of longitudinal steel bars and stirrups tied or welded together; The longitudinal reinforcement bars are arranged along the longitudinal direction of the column; The stirrups are fitted around the longitudinal reinforcing bars to form a cage-like structure; The reinforcing cage is placed inside the 3D-printed concrete permanent formwork on the solid waste base after the formwork is formed.

6. A solid waste-based 3D-printed concrete reinforced steel wire-connected composite column according to any one of claims 1-5, characterized in that, The confinement effect of the solid waste-based 3D-printed concrete permanent formwork on the internal cast-in-place concrete is calculated to correct the compressive strength of the internal cast-in-place concrete. The expression for this is: ； ； ； in, This represents the compressive strength of the internal cast-in-place concrete under the action of the hoop. , The coefficient representing the influence of cross-sectional shape on the hoop effect; The hoop coefficient for permanent formwork of solid waste-based 3D printed concrete; This refers to the design value of the compressive strength of the internal cast-in-place concrete; The percentage of the cross-sectional area of ​​the 3D-printed concrete permanent formwork based on solid waste. The reduction factor for permanent formwork of solid waste-based 3D-printed concrete; The design value for the compressive strength of the permanent formwork for 3D-printed concrete based on solid waste; The total cross-sectional area of ​​the 3D-printed concrete permanent formwork based on solid waste; This refers to the cross-sectional area of ​​the internal cast-in-place concrete. The cross-sectional area of ​​the 3D-printed concrete permanent formwork based on solid waste; The expression for the lateral confining pressure load is: ； ； ； ； ； in, This is a lateral confining pressure load; The effective constraint coefficient; It is the ratio of the volume of the transverse confinement ring reinforcement to the volume of the confinement concrete core. The yield strength of the transverse reinforcing wire; To effectively constrain the area of ​​the concrete; The area of ​​the region surrounded by the reinforcing bars; This represents the cross-sectional area of ​​a single reinforcing wire. The vertical net spacing between the reinforcing steel wires; The length of the reinforcing wire; To constrain the side length of the concrete square column; This is the distance from the center of the reinforcing wire to the edge of the column section; It is the ratio of the longitudinal reinforcement area to the core area of ​​the cross section; The final expression for the compressive strength of the cast-in-place concrete is: ； in, This refers to the compressive strength of the final internal cast-in-place concrete; The expression for the axial compressive bearing capacity of a 3D-printed concrete composite column with wire-reinforced ring reinforcement based on solid waste is as follows: ； in, Axial compressive bearing capacity of 3D-printed concrete ring-reinforced steel wire-connected composite columns based on solid waste; This represents the stability coefficient of the reinforced concrete member. The yield strength of the longitudinal reinforcement; This represents the cross-sectional area of ​​the longitudinal reinforcing bars.

7. A method for fabricating a solid waste-based 3D-printed concrete reinforced concrete composite column with steel wire tie as described in any one of claims 1 to 6, characterized in that, include: The solid waste-based 3D printed concrete permanent template is prepared by using industrial solid waste materials according to a preset design ratio; wherein, the industrial solid waste materials include one or more of nickel-iron slag, slag, fly ash, steel slag, and recycled micro powder as cementing materials or fine aggregate components. The solid waste-based 3D printed concrete permanent template is extruded layer by layer along the circumference of the column by the printing nozzle of the concrete 3D printing equipment to create 3D printed concrete strips. After printing one layer of strip, the printing equipment pauses or adjusts the nozzle position, and the reinforcing wire tie system is placed flat on the surface of that layer of strip. Then, the next layer of strip is printed, so that the reinforcing wire tie system is wrapped between the two adjacent printed strips, forming a hollow outer template that shares the force with the printed layers. The reinforcing wire tie system includes an outer ring of steel wire, an inner ring of steel wire, and tie sections. After printing is completed, a reinforcing cage is installed inside the permanent formwork of the solid waste-based 3D printed concrete; the reinforcing cage consists of longitudinal reinforcing bars and stirrups; Concrete is poured into the interior of the solid waste-based 3D-printed concrete permanent template and vibrated to form the internal cast-in-place concrete. After vibration, smooth the surface of the column top and cover it with plastic film or water it for curing. After curing, a composite column of solid waste-based 3D printed concrete ring reinforcement steel wire is formed. During the curing period, the strength of the permanent formwork of solid waste-based 3D printed concrete and the internal cast-in-place concrete gradually increases. The two form a whole and share the force through the interface bonding and the tie effect of the ring reinforcement steel wire tie system.

8. The method for fabricating a solid waste-based 3D-printed concrete ring-reinforced steel wire-connected composite column according to claim 7, characterized in that, Before placing the reinforcing wire tie system onto the surface of the printing strip, the surface of the reinforcing wire tie system is roughened. Taking advantage of the plasticity of the 3D printed concrete strip after extrusion and the self-compacting interlocking effect of the upper and lower adjacent 3D printed concrete strips after the reinforcing wire is placed, the surface roughened reinforcing wire tie system is placed smoothly on the surface of the current printing strip, and then the printing and extrusion of the next layer of 3D concrete strip is carried out to improve the interfacial bonding strength and anti-slip ability between the reinforcing wire and the printed concrete strip.

9. The method for fabricating a solid waste-based 3D-printed concrete ring-reinforced steel wire-connected composite column according to claim 7, characterized in that, The outer ring steel wire, inner ring steel wire, or tie section of the coiled steel wire tie system is set as a spiral structure. The spiral structure is embedded inside the 3D printed concrete strip and forms a mechanical interlocking anchor with the printed layer.

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