Fine manufacturing method of pipe-concrete combined test component based on 3D printing and magnetic hot melting technology

Abstract

The invention relates to a pipe-concrete combined test component fine manufacturing method based on 3D printing and magnetic hot melting technologies, and belongs to the technical field of 3D printing. The method specifically comprises the steps that the 3D printing technology is adopted, a magnetic hot melt adhesive material is used, and a pipe supporting assembly used for supporting and positioning the distance between adjacent layers of pipes and a reinforcing steel bar supporting assembly used for supporting and positioning the distance between the adjacent pipes and a reinforcing steel bar cage are printed; a base, a vertical sliding supporting arm, a pipe supporting assembly and a steel bar supporting assembly are adopted for accurately positioning all inner-layer pipes and a steel bar cage. Concrete is poured into the outermost-layer pipe; and then applying an alternating magnetic field to melt the magnetic hot melt adhesive material so as to obtain the pipe-concrete combined test member. The tedious procedure of additionally machining an end plate in a traditional method is avoided, and finally the support is removed through a magnetic field melting method, so that the pipe-concrete combined test component is obtained.

Description

Technical Field

[0001] The present invention relates to a refined production method for a pipe-concrete composite test component based on 3D printing and magnetic hot melting technology, and belongs to the technical field of 3D printing. Background Art

[0002] Traditional reinforced concrete components, due to shortcomings such as weak load-bearing and corrosion resistance, and limited relative energy consumption, have made it difficult to meet the requirements of existing super-high-rise building structures and bridge structures. To overcome the limitations of traditional reinforced concrete structures, composite structures composed of various pipes and concrete have been widely used in building and bridge structures, such as steel pipes of various cross-sections, stainless steel pipe concrete, and pipe-constrained concrete components made of various composite materials such as FRP and GFRP. These pipes, by being externally encased in concrete or simultaneously externally encased and internally embedded in concrete, provide constraints for the concrete, subjecting the core concrete to three-dimensional compression, significantly improving the concrete's compressive strength and the component's ductility.

[0003] Accurately preparing the corresponding forms of test components and conducting model tests are necessary prerequisites for obtaining the bearing performance of the above-mentioned different forms of pipe-constrained concrete components. The structure of the pipe-concrete composite component is relatively complex. Usually, not only multiple layers of pipes are required inside the concrete, but sometimes a steel cage is also required. How to ensure that the above-mentioned layers of pipes and steel cages are accurately positioned and do not move or tilt during the subsequent pouring of concrete is the key to making such pipe-concrete composite components. At present, some common methods include additionally processing an end plate, opening grooves on the end plate according to the positions of the built-in pipes, and opening circular holes on the end plate according to the positions of the longitudinal steel bars in the steel cage, and then plug-welding the end plate to the end plate at the bottom of the test component, and finally welding it to the outermost layer of pipes in the composite component. In this method, on the one hand, the added end plate cannot be removed after the component is manufactured. It always serves as an end member to provide constraints for the internal pipes and steel cage, resulting in increased end constraints, which deviates from the actual force form of the original component, and there is a deviation between the obtained test data and the actual data; on the other hand, the diameter and position of the grooves and circular holes opened on the added end plate can only be applied to a certain type of fixed component. When the parameters of the test component need to be changed, such as changing the diameter of the internal pipe, the position and diameter of the longitudinal steel bars in the steel cage, or adding other inner pipes, it is impossible to make changes on the original end plate, and a new end plate needs to be re-processed, which inevitably causes a certain amount of waste. In addition to the above method, a common practice is to weld an iron frame with the same shape as the internal pipe inside the outermost pipe, and then insert the internal pipe into the iron frame to fix it. This method cannot be implemented when it is necessary to add a steel cage or other pipes between the inner and outer layers of pipes due to the presence of the preset iron frame. Prior art publication CN 118700329 B discloses a 3D-printed meter-scale lattice framework reinforced concrete beam component and its fabrication method, including the following steps: S1. Arrange a steel cage; S2. Use large-scale 3D printing technology to construct the meter-scale lattice framework structure; S3. Insert the meter-scale lattice framework structure into the steel cage, secure the cage with wooden formwork, pour reactive powder concrete slurry, and perform curing. However, this method cannot guarantee the precise positioning of the internal pipes and steel cage layers, and prevent them from shifting or tilting during the subsequent concrete pouring process. Summary of the Invention

[0004] In order to solve the technical problems existing in the prior art, the present invention provides a method for the refined production of a pipe-concrete composite test component based on 3D printing and magnetic hot melt technology. The purpose is to provide a method that does not require additional processing of end plates and can accurately position pipes and steel cages. Finally, by applying an alternating magnetic field, the magnetic hot melt adhesive material embedded in the concrete is melted, thereby obtaining a pipe-concrete composite test component with a specific size and position. Specifically, a support assembly made of a magnetic hot melt adhesive material with magnetic hot melt properties is manufactured using 3D printing technology. The support assembly cooperates with a base and a vertical sliding support arm to achieve precise positioning of the pipe and the steel cage. The design of the base and vertical sliding support arm made of steel enhances the bonding force between the pipe and the concrete, avoiding the tedious procedure of additional end plate processing in traditional methods. Finally, the support is removed by a magnetic field melting method, thereby obtaining a pipe-concrete composite test component.

[0005] To achieve the above objectives, the present invention provides a refined production method for a pipe-concrete composite test component based on 3D printing and magnetic hot melting technology, which specifically includes:

[0006] Step 1: Using 3D printing technology to print out a pipe support assembly for supporting and positioning the spacing between adjacent layers of pipes, and a steel bar support assembly for supporting and positioning the spacing between adjacent pipes and the steel cage, wherein the pipe support assembly and the steel bar support assembly are made of a magnetic hot melt adhesive material with magnetic hot melt properties;

[0007] Step 2: Install one end of the pipe support assembly and the steel bar support assembly on each vertical sliding support arm, and install one end of each vertical sliding support arm on the base, and then evenly bond the base along the inner wall of the outermost pipe in an axial direction;

[0008] Step 3: Place each inner layer pipe and steel cage in the set position one by one in the order from the inside to the outside. Then, the other end of the pipe support assembly supports the inner layer pipe, and the steel support assembly supports the steel cage. At this time, the base, vertical sliding support arm, pipe support assembly and steel support assembly together constitute the support skeleton;

[0009] Step 4: pouring concrete into the outermost pipe;

[0010] Step 5: After the concrete solidifies and reaches a certain strength, an alternating magnetic field is applied to the outermost pipe to melt the magnetic hot melt adhesive material with magnetic hot melt properties embedded in the concrete, thereby obtaining a pipe-concrete composite test component.

[0011] Furthermore, the base and the vertical sliding support arm are made of steel.

[0012] Furthermore, the base and the vertical sliding support arm are both made of magnetic hot melt adhesive material using 3D printing technology.

[0013] Furthermore, the steel bar support assembly includes a first support mechanism and a connecting hook. One end of the first support mechanism is connected to the vertical sliding support arm, and the other end of the first support mechanism is connected to the connecting hook. The connecting hook is used to hook the steel bar cage. The first support mechanism has the same structure as the pipe support assembly.

[0014] Furthermore, the pipe support assembly includes a standard support arm, an end support arm and a positioning pin, wherein the standard support arm is used to connect the vertical sliding support arm and the end support arm, and the positioning pin is used to determine the relative position between the vertical sliding support arm and the standard support arm and the relative position between the standard support arm and the end support arm.

[0015] Furthermore, the standard support arm is plugged into the vertical sliding support arm, and the end support arm is plugged into the standard support arm.

[0016] Furthermore, the cross section of the base is concave, the bottom surface of the base is an arc surface that fits the inner wall of the tube, and two opposite inner side walls of the base are provided with a plurality of grooves arranged at equal intervals.

[0017] Furthermore, the vertical sliding support arm includes a slider and a groove, each corner of the slider has a protrusion matching the groove, the slider is fixed to one end of the groove, the two opposite inner walls of the groove are provided with slide grooves, and the inner bottom wall of the groove is reserved with several positioning holes.

[0018] Furthermore, the standard support arm and the end support arm have the same structure, the two opposite outer side walls of the standard support arm have protrusions, the two opposite inner side walls of the standard support arm have slots, and the inner bottom wall of the standard support arm is provided with a plurality of connection holes.

[0019] The present invention discloses a refined manufacturing method for a pipe-concrete composite test component based on 3D printing and magnetic hot melt technology. The beneficial effect is that compared with the existing technology, the pipe support assembly and steel bar support assembly with magnetic hot melt properties are manufactured through 3D printing technology. These components can accurately position and fix different layers of pipes and steel cages. Through the synergistic effect of these components, the relative positions of each layer of pipes and steel cages can be accurately fixed before pouring concrete, avoiding the problem of excessive end constraints caused by the difficulty in removing the end plates in traditional methods, and the component parameters can be flexibly adjusted without the need to reprocess the end plates or iron frames every time they are modified. After pouring concrete, under the action of an external alternating magnetic field, the magnetic hot melt adhesive material embedded in the concrete melts, while the base and vertical sliding support arm made of steel remain in the concrete, enhancing the bonding force between the concrete and the pipe, thereby forming a pipe-concrete composite test component, providing a guarantee for accurate testing of its bearing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 This is a schematic diagram of the base being arranged on the outermost layer of pipe in Example 1 of the present invention;

[0022] Figure 2 This is a schematic diagram of the base structure of the present invention;

[0023] Figure 3 This is a schematic structural diagram of the vertical sliding support arm of the present invention;

[0024] Figure 4 This is a schematic diagram of the standard support arm and positioning pin structure of the present invention;

[0025] Figure 5 This is a schematic diagram of the structure of the end support arm in the pipe support assembly of the present invention;

[0026] Figure 6 This is a schematic diagram of the structure of the end support arm and the connecting hook in the steel bar support assembly of the present invention;

[0027] Figure 7 Schematic diagram of the pipe-concrete composite test component in Example 2 of the present invention.

[0028] As shown in the figure: 1. Base; 2. Vertical sliding support arm; 3. Standard support arm; 4. End support arm; 5. Connecting hook; 6. Inner pipe; 7. Steel cage; 8. Positioning pin; 9. Outermost pipe; 10. Arc surface; 11. Groove; 20. Slider; 21. Concave strip; 22. Protrusion; 23. Slide groove; 24. Positioning hole; 30. Protrusion; 31. Slot; 32. Connecting hole. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] In order to further understand the content of the present invention, this technical solution is further described below in conjunction with specific implementation methods.

[0031] Example 1: Figures 1 to 6 As shown, this embodiment provides a refined production method for a pipe-concrete composite test component based on 3D printing and magnetic hot melting technology. In this embodiment, the pipe-concrete composite test component is divided into two layers, specifically an outermost pipe 9 and an inner pipe 6. A steel cage 7 is provided between the outermost pipe 9 and the inner pipe 6. The pipe-concrete composite test component production method specifically includes:

[0032] Step 1: Using 3D printing technology and magnetic hot melt adhesive material, print out the base 1, the vertical sliding support arm 2, the pipe support assembly for supporting and locating the spacing between adjacent layers of pipes, and the steel bar support assembly for supporting and locating the spacing between adjacent pipes and the steel cage 7;

[0033] The steel bar support assembly includes a first support mechanism and a connecting hook 5, one end of the first support mechanism is connected to the vertical sliding support arm 2, and the other end of the first support mechanism is connected to the connecting hook 5, the connecting hook 5 is used to hook the steel bar cage 7, and the first support mechanism has the same structure as the pipe support assembly; specifically, the first support mechanism includes a standard support arm 3, an end support arm 4 and a positioning pin 8, wherein one end of the vertical sliding support arm 2 is connected to the base 1, the standard support arm 3 is used to connect the vertical sliding support arm 2 and the end support arm 4, the positioning pin 8 is used to determine the relative position between the vertical sliding support arm 2 and the standard support arm 3 and the relative position between the standard support arm 3 and the end support arm 4, and the connecting hook 5 is fixed at one end of the end support arm 4.

[0034] The pipe support assembly also includes a standard support arm 3, an end support arm 4 and a positioning pin 8, wherein the standard support arm 3 is used to connect the vertical sliding support arm 2 and the end support arm 4, the positioning pin 8 is used to determine the relative position between the vertical sliding support arm 2 and the standard support arm 3 and the relative position between the standard support arm 3 and the end support arm 4, and the end support arm 4 of the pipe support assembly is used to support the inner layer pipe 6.

[0035] As a specific implementation of this embodiment, the standard support arm 3 is plugged into the vertical sliding support arm 2, and the end support arm 4 is plugged into the standard support arm 3; specifically, the cross section of the base 1 is concave, the bottom surface of the base 1 is an arc surface 10 that fits the inner wall of the pipe, and the two opposite inner side walls of the base 1 are provided with a plurality of grooves 11 arranged at equal intervals; the vertical sliding support arm 2 includes a slider 20 and a concave strip 21, and the slider 20 has a protrusion 22 that matches the groove 11 at the four corners. The protrusion 22 is a smooth arc surface. The operator inserts the protrusion 22 into the groove 11, that is, uses the protrusion 22 on the vertical sliding support arm 2 to fit the base 1 The groove 11 of the base 1 is matched with the groove 11 of the base 1, and a plurality of vertical sliding support arms 2 are fixed to different height positions at a certain interval. The slider 20 is fixed to one end of the groove 21. The two opposing inner walls of the groove 21 are provided with a slide groove 23 parallel to the length of the groove 21. The inner bottom wall of the groove 21 is reserved with multiple positioning holes 24. The standard support arm 3 and the end support arm 4 have the same structure. The two opposing outer walls of the standard support arm 3 and the end support arm 4 are each provided with a protrusion 30. The two opposing inner walls of the standard support arm 3 and the end support arm 4 are each provided with a slot 31. The inner bottom wall of the standard support arm 3 and the end support arm 4 is provided with multiple connection holes 32. When the standard support arm 3 is plugged into the vertical sliding support arm 2, the protrusion 30 of the standard support arm 3 is precisely embedded in the slide groove 23 of the vertical sliding support arm 2. When the standard support arm 3 is plugged into the end support arm 4, the protrusion 30 of the end support arm 4 is precisely embedded in the slot 31 of the standard support arm 3. When the position of the vertical sliding support arm 2 on the base 1 needs to be adjusted, the operator pushes the slider 20 by hand to make the protrusion 22 slide out of the current groove 11, and continues to push the slider 20 to insert it into other grooves 11, thereby achieving the height adjustment of this vertical sliding support arm 2 on the base 1; the number of vertical sliding support arms 2 on the base 1 can also be increased or reduced according to actual needs.

[0036] Step 2: Install one end of the pipe support assembly and the steel support assembly on each vertical sliding support arm 2, and install one end of each vertical sliding support arm 2 on the base 1. Then, evenly bond the base 1 along the inner wall of the outermost pipe 9 in the axial direction. Specifically, according to the number and height of the pipes and steel cage 7 required for the pipe-concrete composite test component, use several standard support arms 3 and end support arms 4 to cooperate with each other for installation, and pass the positioning pin 8 through the connection hole 32 of the standard support arm 3 and the positioning hole 24 of the vertical sliding support arm 2. The positioning pin 8 is passed through the connection hole 32 of the standard support arm 3 and the connection hole 32 of the end support arm 4. That is, the steel support assembly and the steel bar support assembly are connected to the vertical sliding support arm 2 through the positioning pin 8. The sliders 20 of each vertical sliding support arm 2 are respectively installed in the grooves 11 of the base 1 at different heights, thereby fixing the steel support assembly and the steel bar support assembly at the specified heights of the base 1 respectively; then, the base 1 and the inner wall of the outermost pipe 9 are firmly bonded along the inner wall of the outermost pipe 9 in the circumferential direction and the height direction;

[0037] Step 3, in the order from the inside to the outside, place the inner pipe 6 and the steel cage 7 in the set position, and then adjust the length of the standard support arm 3 inserted into the vertical sliding support arm 2 and the length of the end support arm 4 inserted into the standard support arm 3 according to the distance between the outermost pipe 9 and the inner pipe 6, and then each positioning pin 8 passes through the corresponding positioning hole 24 and the connecting hole 32, as well as the corresponding connecting hole 32 between the standard support arm 3 and the end support arm 4, to complete the relative position between the vertical sliding support arm 2 and the standard support arm 3 and the relative position between the standard support arm 3 and the end support arm 4, so as to ensure that the end support arm 4 of the pipe support assembly is against the outer wall of the inner pipe 6; similarly, at the same time, according to the outermost The spacing between the layer pipe 9 and the steel cage 7 is adjusted, and the length of the standard support arm 3 inserted into the vertical sliding support arm 2 and the length of the end support arm 4 inserted into the standard support arm 3 are adjusted. Then, each positioning pin 8 passes through the corresponding positioning hole 24 and the connecting hole 32, as well as the corresponding connecting hole 32 of the standard support arm 3 and the end support arm 4, to complete the relative position between the vertical sliding support arm 2 and the standard support arm 3 and the relative position between the standard support arm 3 and the end support arm 4. Locking to ensure that the connecting hook 5 of the steel support assembly hooks the longitudinal steel bars of the column steel cage 7. At this time, each base 1, pipe support assembly and steel support assembly together constitute a support skeleton, which accurately positions the inner pipe 6 and the steel cage 7 at the corresponding positions;

[0038] Step 4: After the number and height of the pipes and steel cages 7 required for the pipe-concrete composite test component are positioned and supported according to step 3, concrete can be poured into the outermost pipe 9;

[0039] In step 5, after the concrete solidifies and reaches a certain strength, an alternating magnetic field is applied to the outermost pipe 9. In this embodiment, the alternating magnetic field strength is in the range of 5-15 kA / m, the alternating heating current is in the range of 10-100 A, and the magnetic field frequency is in the range of 100-180 kHz. The magnetic hot melt adhesive material with magnetic hot melt properties embedded in the concrete is melted into a viscous liquid. The melted magnetic hot melt adhesive material is bonded to the concrete and the pipe, thereby obtaining a pipe-concrete composite test component.

[0040] This embodiment utilizes 3D printing technology and a magnetic hot melt adhesive material with magnetic thermoplastic properties to print a base 1, vertical sliding support arms 2, a pipe support assembly for supporting and positioning the spacing between adjacent layers of pipes, and a steel bar support assembly for supporting and positioning the spacing between adjacent pipes and steel cages 7. The pipe and steel bar support assemblies provide support for each layer of pipes and steel cages 7, achieving the precise positioning of each layer of pipes and steel cages 7 in the pipe-concrete composite test component. Once all pipes and steel cages 7 are in place, concrete can be poured between the designated layers. Once the concrete reaches a certain strength, an alternating magnetic field is applied to the exterior of the pipe-concrete composite test component to melt the magnetic hot melt adhesive material embedded in the concrete, thereby producing the pipe-concrete composite test component.

[0041] The above-mentioned steel bar support assembly includes a first support mechanism and a connecting hook 5, and the connecting hook 5 is used to hook the steel cage 7. The pipe support assembly includes a standard support arm 3, an end support arm 4 and a positioning pin 8. The slider 20 of the vertical sliding support arm 2 can move up and down along the base 1 and is fixed at the corresponding groove 11, so that the pipe support assembly is fixed at the corresponding height. Each base 1 is evenly distributed along the circumferential direction of the inner wall of the outermost pipe 9, and the length direction of the base 1 is set along the axial direction of the outermost pipe 9. The steel bar support assembly and the pipe support assembly are staggered and fixed on the base 1 at a certain interval. After all the inner pipes 6 and steel cages 7 are in place, concrete can be poured into the outermost pipe 9. After the concrete reaches a certain strength, an alternating magnetic field is applied to melt the magnetic hot melt adhesive material with magnetic hot melt properties embedded in the concrete to obtain the pipe-concrete test component.

[0042] Example 2: Figures 1 to 7 As shown, unlike Example 1, the pipe-concrete composite test member in this embodiment is divided into three layers. The three layers of pipes are, from the outside to the inside, the outermost pipe 9, the inner pipe 6, and the innermost pipe 6. A first layer of steel cage 7 is provided between the outermost pipe 9 and the inner pipe 6, and a second layer of steel cage 7 is provided between the inner pipe 6 and the innermost pipe 6. The innermost pipe 6 and the second layer of steel cage 7 are not shown in the figure. The base 1 and the vertical sliding support arm 2 are both made of steel. The method for manufacturing the pipe-concrete composite test member specifically includes:

[0043] Step 1: Using 3D printing technology and magnetic hot melt adhesive material with magnetic hot melt properties, print out pipe support components for supporting and positioning the spacing between adjacent layers of pipes, and steel bar support components for supporting and positioning the spacing between adjacent pipes and the steel cage 7;

[0044] The steel bar support assembly includes a first support mechanism and a connecting hook 5. One end of the first support mechanism is connected to the vertical sliding support arm 2, and the other end of the first support mechanism is connected to the connecting hook 5. The connecting hook 5 is used to hook the steel bar cage 7. The first support mechanism has the same structure as the pipe support assembly. The vertical sliding support arm 2 can move along the base 1 under the action of force, thereby adjusting the position of the vertical sliding support arm 2 on the base 1. The structures of the pipe support assembly and the steel bar support assembly in this embodiment are the same as those in Example 1, so they will not be repeated in this embodiment.

[0045] As a specific implementation of this embodiment, the standard support arm 3 is plugged into the vertical sliding support arm 2, and the end support arm 4 is plugged into the standard support arm 3; specifically, the cross section of the base 1 is concave, the bottom surface of the base 1 is an arc surface 10 that fits the inner wall of the pipe, and the two opposite inner side walls of the base 1 are provided with grooves 11 arranged at equal intervals; the vertical sliding support arm 2 includes a slider 20 and a concave strip 21, and the slider 20 has protrusions 22 at the four corners that match the grooves 11. The operator inserts the protrusions 22 into the grooves 11 to vertically slide the support arm 2. The arm 2 is fixed to the base 1, and the slider 20 is fixed to one end of the groove 21. The two opposing inner walls of the groove 21 are provided with slide grooves 23 parallel to the length of the groove 21. The inner bottom wall of the groove 21 is reserved with multiple positioning holes 24. The standard support arm 3 and the end support arm 4 have the same structure. The two opposing outer walls of the standard support arm 3 and the end support arm 4 each have a protrusion 30, the two opposing inner walls of the standard support arm 3 and the end support arm 4 each have a slot 31, and the inner bottom walls of the standard support arm 3 and the end support arm 4 each have multiple connection holes 32. When the standard support arm 3 is plugged into the vertical sliding support arm 2, the protrusion 30 of the standard support arm 3 fits neatly into the slide groove 23 of the vertical sliding support arm 2. When the standard support arm 3 is plugged into the end support arm 4, the protrusion 30 of the end support arm 4 fits neatly into the slot 31 of the standard support arm 3.

[0046] Step 2 in this embodiment is the same as step 2 in embodiment 1, and therefore will not be described in detail.

[0047] Step 3, in the order from the inside to the outside, place the innermost pipe, the second layer of steel cage, the inner pipe 6, and the first layer of steel cage 7 in the set position, and then adjust the length of the standard support arm 3 inserted into the vertical sliding support arm 2 and the length of the end support arm 4 inserted into the standard support arm 3 according to the distance between the innermost pipe and the inner pipe 6. Then, each positioning pin 8 passes through the corresponding positioning hole 24 and the connecting hole 32, as well as the corresponding connecting hole 32 between the standard support arm 3 and the end support arm 4, to complete the relative position between the vertical sliding support arm 2 and the standard support arm 3 and the relative position between the standard support arm 3 and the end support arm 4. Locking to ensure The end support arm 4 of the pipe support assembly is against the outer wall of the innermost pipe; at the same time, according to the distance between the innermost pipe and the second layer of steel cage, the length of the standard support arm 3 inserted into the vertical sliding support arm 2 and the length of the end support arm 4 inserted into the standard support arm 3 are adjusted, and then each positioning pin 8 passes through the corresponding positioning hole 24 and the connecting hole 32, as well as the corresponding connecting hole 32 of the standard support arm 3 and the end support arm 4, completing the locking of the relative positions between the vertical sliding support arm 2 and the standard support arm 3 and the relative positions between the standard support arm 3 and the end support arm 4, so as to ensure that the connecting hook 5 of the steel bar support assembly hooks the longitudinal steel bars of the second layer of steel cage;

[0048] Similarly, according to the spacing between the outermost pipe 9 and the inner pipe 6, the relative positions of the vertical sliding support arm 2 and the standard support arm 3, as well as the relative positions of the standard support arm 3 and the end support arm 4 are locked to ensure that the end support arm 4 of the pipe support assembly is against the outer wall of the inner pipe 6; according to the spacing between the outermost pipe 9 and the first layer of steel cage 7, the relative positions of the vertical sliding support arm 2 and the standard support arm 3, as well as the relative positions of the standard support arm 3 and the end support arm 4 are locked to ensure that the connecting hook 5 of the steel cage support assembly hooks the longitudinal steel bars of the first layer of steel cage 7; at this time, each base 1, vertical sliding support arm 2, pipe support assembly and steel cage support assembly jointly accurately position the innermost pipe, the second layer of steel cage, the inner pipe 6 and the steel cage 7 in the corresponding positions;

[0049] Step 4: After the pipes, reinforcement cage layers and height required for the pipe-concrete composite test component are positioned and supported according to step 3, concrete can be poured into the outermost pipe 9;

[0050] Step 5: After the concrete solidifies and reaches a certain strength, an alternating magnetic field is applied to the outermost pipe 9. The alternating magnetic field strength is in the range of 5-15 kA / m, the alternating heating current is in the range of 10-100 A, and the magnetic field frequency is in the range of 100-180 kHz. The magnetic hot melt adhesive materials with magnetic hot melt properties embedded in the concrete are melted. At this time, the base 1 and the vertical sliding support arm 2 remain in the concrete. Compared with Example 1 in which the base 1 and the vertical sliding support arm 2 are both melted, this design of Example 2 enhances the bonding force between the concrete and the pipe, thereby obtaining a reinforced pipe-concrete composite test component.

[0051] It should be noted that if there are pipes or steel cages inside the innermost pipe layer, corresponding pipe support assemblies or steel support assemblies must also be added inside the pipe to provide support for the pipe or steel cage 7 installed inside it, so as to achieve precise positioning of the pipe and steel cage 7. When the pipe-concrete composite test member is long, the base 1, vertical sliding support arm 2, pipe support assembly, and steel support assembly can be arranged in sections along the length of the member and installed step by step.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A refined production method for pipe-concrete composite test components based on 3D printing and magnetic hot melting technology, characterized in that: Specifically include: Step 1: using 3D printing technology to print out a pipe support assembly for supporting and positioning the spacing between adjacent layers of pipes, and a steel bar support assembly for supporting and positioning the spacing between adjacent pipes and the steel bar cage (7), wherein the pipe support assembly and the steel bar support assembly are made of magnetic hot melt adhesive material; Step 2: Install one end of the pipe support assembly and the steel bar support assembly on each vertical sliding support arm (2), and install one end of each vertical sliding support arm (2) on the base (1), and then evenly bond the base (1) along the inner wall of the outermost pipe (9) in an axial direction; Step 3, in order from the inside to the outside, each inner layer pipe (6) and steel cage (7) is placed in the set position one by one, and then the other end of the pipe support assembly supports the inner layer pipe (6), and the steel support assembly supports the steel cage (7). At this time, each base (1), vertical sliding support arm (2), pipe support assembly and steel support assembly together constitute a support skeleton; Step 4, pouring concrete into the outermost pipe (9); Step 5: After the concrete solidifies and reaches a certain strength, an alternating magnetic field is applied to the outermost pipe (9) to melt the magnetic hot melt adhesive material with magnetic hot melt properties embedded in the concrete, thereby obtaining a pipe-concrete composite test component.

2. The refined production method of pipe-concrete composite test components based on 3D printing and magnetic hot melting technology according to claim 1 is characterized in that: The base (1) and the vertical sliding support arm (2) are made of steel.

3. The refined production method of pipe-concrete composite test components based on 3D printing and magnetic hot melting technology according to claim 1 is characterized in that: The base (1) and the vertical sliding support arm (2) are both made of magnetic hot melt adhesive material using 3D printing technology.

4. The refined production method of pipe-concrete composite test components based on 3D printing and magnetic hot melting technology according to claim 1 is characterized in that: The steel bar support assembly comprises a first support mechanism and a connecting hook (5), one end of the first support mechanism is connected to the vertical sliding support arm (2), and the other end of the first support mechanism is connected to the connecting hook (5), and the connecting hook (5) is used to hook the steel bar cage (7). The first support mechanism has the same structure as the pipe support assembly.

5. The refined production method of pipe-concrete composite test components based on 3D printing and magnetic hot melting technology according to claim 4 is characterized in that: The pipe support assembly comprises a standard support arm (3), an end support arm (4) and a positioning pin (8), wherein the standard support arm (3) is used to connect the vertical sliding support arm (2) and the end support arm (4), and the positioning pin (8) is used to determine the relative position between the vertical sliding support arm (2) and the standard support arm (3) and the relative position between the standard support arm (3) and the end support arm (4).

6. The refined production method of pipe-concrete composite test components based on 3D printing and magnetic hot melting technology according to claim 5 is characterized in that: The standard support arm (3) is plugged into the vertical sliding support arm (2), and the end support arm (4) is plugged into the standard support arm (3).

7. The refined production method of pipe-concrete composite test components based on 3D printing and magnetic hot melting technology according to claim 1 is characterized in that: The cross section of the base (1) is concave, the bottom surface of the base (1) is an arc surface (10) that fits the inner wall of the pipe, and two opposite inner side walls of the base (1) are provided with a plurality of grooves (11) arranged at equal intervals.

8. The refined production method of pipe-concrete composite test components based on 3D printing and magnetic hot melting technology according to claim 5 is characterized in that: The vertical sliding support arm (2) includes a slider (20) and a concave strip (21). Each corner of the slider (20) is provided with a protrusion (22) matching the groove (11). The slider (20) is fixed to one end of the concave strip (21). Two opposite inner side walls of the concave strip (21) are provided with a slide groove (23). The inner bottom wall of the concave strip (21) is reserved with a plurality of positioning holes (24).

9. The refined production method of pipe-concrete composite test components based on 3D printing and magnetic hot melting technology according to claim 5 is characterized in that: The standard support arm (3) and the end support arm (4) have the same structure. The two opposite outer side walls of the standard support arm (3) are provided with protrusions (30), the two opposite inner side walls of the standard support arm (3) are provided with slots (31), and the inner bottom wall of the standard support arm (3) is provided with a plurality of connection holes (32).

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