Method and device for manufacturing a steel-fiber ring-distributed concrete pipe

Abstract

The application discloses a kind of steel fiber annular distribution concrete pipeline preparation method and device, including material transport vehicle, support frame and forming drum, the support frame includes the fixed support of two sides, guide rail connected two sides fixed support and height adjusting mechanism that can adjust the height of guide rail erection, the both ends of fixed support are erected in the both ends of forming drum, and guide rail is along the length direction of forming drum and is worn out;Material transport vehicle is fixedly installed with hopper, the upper portion of hopper is conical inlet, and the lower portion is tubular discharge part, and magnetic guide component is arranged on the periphery of tubular discharge part, and magnetic guide component can make steel fiber in tubular discharge part axial directional arrangement along tubular discharge part;Forming drum rotates along its axis under external driving force, provides centrifugal force;The minimum distance between lower end of hopper and inner wall of forming drum cannot be less than the maximum value of steel fiber length. Solve the problem that existing process cannot greatly reduce dependence on power coil, realize the annular distribution of steel fiber along concrete pipeline.

Description

Technical Field

[0001] This invention relates to the field of concrete pipe manufacturing technology, and in particular to a method and apparatus for manufacturing circumferentially distributed steel fiber concrete pipes. Background Technology

[0002] Concrete pipes possess advantages such as high rigidity, corrosion resistance, and convenient construction, and are widely used in various underground water conveyance and drainage projects. They are a core foundational building material for ensuring urban and rural water conservancy construction and municipal pipeline network operation and maintenance. Ordinary concrete itself has defects such as low tensile strength, poor toughness, and susceptibility to cracking. During pouring, curing, and service, it is prone to cracking due to multiple stresses caused by temperature, shrinkage, soil load, and uneven ground settlement, leading to pipe leakage, surface spalling, structural loosening and damage, and affecting the safety and stability of the pipeline network. Currently, the industry often uses reinforcement modification to improve the mechanical properties of concrete pipes: traditional steel mesh reinforcement involves numerous procedures and high manual dependence, easily resulting in uneven reinforcement density and localized missing reinforcement, leading to pipeline stress imbalance and poor crack resistance enhancement. Furthermore, for schemes that randomly add steel fibers, the fibers are randomly distributed within the concrete, making it difficult to adapt to the predominantly circumferential stress conditions of the pipeline, resulting in only a small improvement in tensile and crack resistance and low fiber utilization.

[0003] Chinese patent CN119871645A discloses a visualized circumferentially oriented steel fiber shield tunnel segment concrete mold, which uses a double-loop coil to control the distribution direction of the inner layer of steel fibers in the shield tunnel segment, achieving the effects of steel fiber reinforcement, toughening, and crack resistance. Chinese patent CN119369526A discloses a centrifugal molding device and method for oriented steel fiber reinforced concrete hollow pipe piles. It involves winding a coil around the outer surface of a PVC hollow pipe mold, pouring slurry into the PVC hollow pipe mold, and simultaneously using a magnetic field to control the direction of the steel fibers during centrifugal compaction. Chinese patent CN119748637A discloses a horizontal two-dimensional oriented steel fiber UHPC wind turbine tower ring sheet preparation device and method. Using a DC power supply, a magnetic slider is moved on a ring track, achieving circumferential distribution of steel fibers. In summary, most existing technologies for achieving circumferentially oriented steel fiber arrangement rely on an energized coil wrapped around the outside of the mold to generate a magnetic field to control fiber orientation. This method has significant limitations on the molding size of concrete pipe specimens. Furthermore, when the specimen size increases, the current needs to be increased to obtain an effective magnetic field that meets the orientation requirements. This can easily lead to safety hazards such as overheating and leakage during the on-site preparation process.

[0004] Therefore, it is necessary to propose a method and apparatus for preparing circumferentially distributed steel fiber concrete pipes, which can significantly reduce the dependence of existing molding processes on energized coils and realize the preparation of large-size concrete pipes for industrial applications. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method and apparatus for preparing circumferentially distributed steel fiber concrete pipes, which solves the problem that existing processes cannot significantly reduce their dependence on energized coils, realizes the circumferential distribution of steel fibers along the concrete pipes, and promotes practical engineering applications.

[0006] The technical solution adopted by the present invention to solve the aforementioned problem is: In a first aspect, the present invention provides a device for preparing steel fiber circumferentially distributed concrete pipes, comprising a material transport vehicle, a support frame, and a forming roller. The support frame includes fixed brackets on both sides, guide rails connecting the fixed brackets on both sides, and a height adjustment mechanism that can adjust the height of the guide rails. The two ends of the fixed brackets are mounted on the two ends of the forming roller, and the guide rails extend out along the length of the forming roller. The material transport vehicle can slide back and forth on the guide rail of the support frame; a hopper is fixedly installed on the material transport vehicle, the upper part of the hopper is a conical inlet, and the lower part is a tubular outlet. Magnetic guiding components are arranged around the tubular outlet, and the magnetic guiding components can make the steel fibers in the tubular outlet oriented along the axial direction of the tubular outlet. The size of the forming roller is adapted to the length of the concrete pipe to be processed. The forming roller rotates along its axis under external driving force, providing centrifugal force. The minimum distance between the lower end of the hopper and the inner wall of the forming roller must not be less than the maximum length of the steel fiber.

[0007] Furthermore, driven surfaces that mesh with or are frictionally driven by the driving wheels are provided on both ends of the forming roller; two driving wheels are symmetrically arranged on both sides of each driven surface, for a total of four driving wheels. Each driving wheel is driven by an independent auxiliary driving motor. All driving motors are synchronously controlled and rotate in the same direction. The driving wheels are in close contact with the outer walls of the driven surfaces at both ends of the forming roller or are driven by gear meshing. The driving motor drives the driving wheels to rotate, and the roller as a whole is driven to maintain a low roller speed by the friction or gear meshing force between the driving wheels and the forming roller. V 1. Rotate smoothly.

[0008] Furthermore, the magnetic permeable component is implemented by winding a magnetic permeable coil, in which case the power supply equipment for generating a magnetic field to power the coil is installed on the material transport vehicle; or it is implemented by using a ring magnet, with a ring magnet sleeved on the tubular discharge section, the ring magnet being entirely fitted onto the outer surface of the tubular discharge section, the tubular discharge section being made of non-magnetic material, and a limiting part being provided at the lower part of the tubular discharge section to restrict the embedded state of the ring magnet in the tubular discharge section; if the height of the ring magnet is much smaller than the height of the tubular discharge section, multiple ring magnets are stacked along the height direction.

[0009] Furthermore, the conical inlet is connected to the steel fiber concrete slurry supply unit, and the device also includes a control system. The control system is electrically connected to the steel fiber concrete slurry supply unit, the drive component of the material transport vehicle, and the drive component of the molding roller, and controls the coordinated operation of each part.

[0010] Furthermore, the device is equipped with multiple sets of material transport vehicles on the support frame, which are used to segment and move materials according to the pipe forming area.

[0011] Secondly, the present invention provides a method for preparing a circumferentially distributed steel fiber concrete pipe, the preparation method using the aforementioned apparatus, comprising the following steps: Step 1: Set up the support frame along the length of the forming roller. Place the material transport vehicle on the guide rail of the support frame. Fix the hopper on the material transport vehicle. The lower tubular discharge section of the hopper is located outside the guide rail. Magnetic guiding components are arranged around the tubular discharge section to pre-establish a uniform magnetic field environment that allows the steel fibers to be oriented axially along the tubular discharge section. Simultaneously, turn on the drive component of the forming roller to drive the forming roller to maintain a low roller speed. V 1. Smooth rotation; Step 2: Add steel fiber reinforced concrete mixture to the hopper on the material transport vehicle, and control the mixture at a constant discharge rate. V 2. The material falls evenly and continuously from the hopper outlet. After the forming roller rotates once, the control system controls the material transport vehicle to automatically move forward a certain distance along the guide rail of the support frame. d The directional movement of the material transport vehicle, combined with the low-speed rotation of the forming drum, ensures that the mixture is evenly spread on all areas of the inner wall of the drum. Step 3: After the material is fed into the forming drum cavity, stop discharging material from the hopper and gradually increase the rotation speed of the forming drum. Under the continuous action of high-speed centrifugal force, the concrete mixture is tightly attached to the inner wall of the forming drum, expelling internal air bubbles and pores, and obtaining a concrete pipe with steel fibers distributed in a ring that meets the density requirements.

[0012] Furthermore, V 1. No more than 60 revolutions per minute.

[0013] Furthermore, the discharge rate of the steel fiber reinforced concrete mixture... V 2. Rotation speed of the forming roller V 1. There is a linear relationship, meaning that the time required for one revolution of the drum is 60 / V Within 1, the discharge length of the mixture is equal to the circumference of the drum 2πr, and the low drum speed of the forming drum is... V 1. Discharge rate of the mixture V 2 are respectively: .

[0014] Furthermore, if the length of the concrete pipe to be processed is too long, several material transport vehicles can be set up to distribute the material in sections, so that the material distribution in the entire forming roller can be completed before the concrete sets.

[0015] Thirdly, the present invention provides a steel fiber circumferentially distributed concrete pipe, which is prepared using the above-described apparatus or obtained using the above-described method.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: By achieving an orderly circumferential distribution of steel fibers inside concrete pipes, it is possible to effectively adapt to circumferential stress conditions, suppress the initiation and propagation of circumferential cracks, and make up for many defects in existing reinforcement and steel fiber addition technologies. It has significant engineering application value and promotion prospects. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the steel fiber circumferentially distributed concrete pipe preparation device of the present invention; Figure 2 This is a schematic diagram of the installation structure of a material transport vehicle and a hopper in one embodiment of the device of the present invention.

[0018] In the diagram, there is a material transport vehicle (1), a drive wheel (2), a support frame (3), a forming roller (4), a pulley (5), a hopper (6), a magnetic guide component (7), and a power supply device (8). Detailed Implementation

[0019] To make the objectives and technical solutions of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. The specific embodiments of this invention are not limited thereto; any equivalent modifications and improvements made by those skilled in the art without substantial innovation should be within the protection scope of this invention.

[0020] This invention provides a method and apparatus for preparing circumferentially distributed steel fiber concrete pipes. Based on the traditional centrifugal preparation method for concrete pipes, this apparatus achieves circumferential distribution of steel fibers by controlling the orientation of steel fibers during the discharge stage of the steel fiber concrete mixture, thereby improving the overall utilization efficiency of steel fibers under circumferential tension and compression conditions and effectively suppressing the probability of crack formation.

[0021] This invention relates to a device for preparing steel fiber circumferentially distributed concrete pipes (see...). Figure 1-2 ), including material transport vehicle 1, support frame 3, and forming roller 4, The support frame 3 includes fixed brackets on both sides, guide rails connecting the fixed brackets on both sides, and a height adjustment mechanism that can adjust the height of the guide rails. The two ends of the fixed brackets are mounted on the two ends of the forming roller 4, and the guide rails extend out along the length of the forming roller. The material transport vehicle 1 is symmetrically equipped with pulleys 5 at its lower part. The pulleys cooperate with the guide rails on the support frame, and the drive component drives the material transport vehicle to slide back and forth on the guide rails of the support frame. A hopper 6 is fixedly installed on the material transport vehicle. The upper part of the hopper 6 is a conical inlet, and the lower part is a tubular outlet. The tubular outlet is generally made of non-magnetic materials such as PVC, plastic, or fiberglass. Magnetic guiding components 7 are arranged around the tubular outlet. The magnetic guiding components are implemented by winding magnetic coils. In this case, the power supply device 8 (such as a constant voltage source) that powers the coil to generate a magnetic field is installed on the material transport vehicle 1. Alternatively, a ring magnet can be used. A ring magnet is fitted over the tubular outlet, and the entire ring magnet is fitted onto the outer surface of the tubular outlet. A limiting part is set at the lower part of the tubular outlet to restrict the embedded state of the ring magnet and prevent it from falling out. The conical inlet is connected to the steel fiber reinforced concrete slurry supply unit. If the height of the ring magnet is much smaller than the height of the tubular outlet, multiple ring magnets can be stacked along the height direction.

[0022] The forming roller 4 consists of a pair of half-cylinders with identical appearance and size. The half-cylinders are assembled with fastening bolts to form a detachable structure, which facilitates mold disassembly and assembly, internal cleaning and maintenance, component demolding and inspection, and equipment transportation and transfer. At the same time, it ensures that the overall roundness and structural rigidity of the combined roller meet the forming requirements.

[0023] The size of the forming roller 4 is adapted to the length of the concrete pipe to be processed. Driven surfaces that mesh with or are frictionally driven by the drive wheels 2 are provided on both ends of the forming roller. Two drive wheels 2 are symmetrically arranged on both sides of each driven surface, for a total of four drive wheels. Each drive wheel is driven by an independent auxiliary drive motor. All drive motors are synchronously controlled and rotate in the same direction. The drive wheels are tightly fitted to the outer walls of the driven surfaces at both ends of the forming roller 4 or are driven by gear meshing. The drive motors drive the drive wheels 2 to rotate, and the roller as a whole maintains a low roller speed due to the friction or gear meshing force between the drive wheels 2 and the forming roller 4. V 1. Rotate smoothly.

[0024] Annular sealing plates are provided on the outer side of the driven surface at both ends of the forming roller. The height of the annular sealing plates relative to the inner wall of the forming roller is not less than the thickness of the concrete pipe to be processed, and does not affect the material transport vehicle's feeding operation through the hopper.

[0025] The material transport vehicle 1 is mounted on top of the support frame 3. The support frame has sufficient structural rigidity to stably support the transport vehicle and the internal steel fiber concrete mixture. The support frame is equipped with a height adjustment mechanism, which can flexibly adjust the relative distance between the lower end of the hopper 6 and the inner wall of the forming roller 4. The minimum distance cannot be less than the maximum value of the steel fiber length, so that the gap between the two is controlled within a reasonable range to avoid problems such as the mixture scattering and uneven distribution.

[0026] The support frame 3 is equipped with guide rails, and the material transport vehicle 1 moves a distance along the guide rails in a single operation. d This distance parameter is equal to the inner diameter of the discharge port of hopper 6. This distance parameter ensures a close fit with the previous material drop area, eliminates uneven material distribution, and ensures continuous and complete paving of steel fiber reinforced concrete mixture without any breaks.

[0027] After the material transport vehicle moves from one end of the forming roller 4 to the other along the guide rail on the support frame 3, if the thickness of the spread mixture in the roller does not reach the preset wall thickness, the material transport vehicle 1 is automatically controlled to move back and forth along both ends of the roller multiple times to continuously replenish the material until the forming wall thickness meets the design requirements.

[0028] In this invention, if the length of the precast concrete pipe is too long, it can be processed in sections. Multiple material transport vehicles 1 can be used, each with a conical inlet on its hopper connected to a steel fiber reinforced concrete slurry supply unit. Each material transport vehicle is responsible for the fabrication of its own section of pipe, and the reciprocating range of the vehicle is the length of the current section. Multiple material transport vehicles can work simultaneously to meet the setting time requirements of the mixture.

[0029] The specific operation steps of the preparation method of the present invention are as follows: Step 1: Erect the support frame along the length of the forming roller 4. Place the material transport vehicle on the guide rail of the support frame. Fix the hopper 6 on the material transport vehicle. The lower tubular discharge section of the hopper 6 is located outside the guide rail. Magnetic guide components are arranged around the tubular discharge section to pre-establish a uniform magnetic field environment that allows the steel fibers to be oriented axially along the tubular discharge section. Simultaneously, the four drive motors on both sides of the forming roller are turned to rotate the drive wheels 2. The friction or gear meshing force between the drive wheels 2 and the forming roller 4 drives the forming roller to maintain a low roller speed. V 1. Smooth rotation allows for the directional arrangement of steel fibers along the circumferential direction of the forming roller; Step 2: Add steel fiber reinforced concrete mixture to hopper 6 on material transport vehicle 1, and control system controls the mixture to discharge at a constant rate. V 2. The material falls evenly and continuously from the outlet of hopper 6. After the forming roller 4 rotates once, the control system controls the material transport vehicle 1 to automatically move forward a certain distance along the guide rail of the support frame 3. d The directional movement of the material transport vehicle 1, combined with the low-speed rotation of the forming roller 4, allows the mixture to be evenly spread in all areas of the inner wall of the roller. Step 3: After the material is placed into the cavity of the forming roller 4, stop the material discharge from the hopper, and gradually increase the output power of the auxiliary drive motor of the drive wheel 2. Under the continuous action of high-speed centrifugal force (the specific speed is determined based on experience or experiment), the concrete mixture adheres tightly to the inner wall of the forming roller 4, expelling the internal air bubbles and pores, and gradually reducing the gaps between particles. The concrete mixture gradually transitions from a loose spreading state to a compacted state, effectively ensuring the density requirements for the forming of concrete pipes.

[0030] Before placing the concrete into the forming drum cavity, the total amount of material used, the length and wall thickness of the concrete pipe to be processed are known, and it can be determined whether the concrete can remain in an uncured state within the time limit for placing the concrete. If the length of the concrete pipe to be processed is too long, several material transport vehicles can be set up to place the concrete in sections, so that the placing of the entire concrete into the forming drum is completed before the concrete curing.

[0031] When the forming roller 4 rotates at a constant speed, the centrifugal pressure generated per unit area of ​​thin-layer mixture is... p c With pipe inner diameter r (Generally 25cm~2m), drum speed V Thickness of the mixture t and density of the mixture ρ The parameters are related and can be calculated according to formula (1). p c The value is taken as the static pressure generated by the self-weight of the thin-layer mixture per unit area. p g When using formula (2), the low drum speed can be determined. V The recommended value is 1, at which the material is distributed radially only along the inner wall of the drum; (1) (2) in, r The unit is meters. V 1. No more than 60 revolutions per minute.

[0032] The discharge rate of the steel fiber reinforced concrete mixture V 2. Rotation speed of the forming roller V 1. There is a linear relationship, that is, within the time it takes for the drum to rotate once, the discharge length of the mixture is equal to the circumference of the drum. Furthermore, the two speed parameters are adjusted synchronously as the wall thickness increases, ensuring quantitative, uniform, and continuous material distribution, effectively preventing material accumulation, local material shortages, and uneven material distribution.

[0033] The process of gradually increasing the output power of the auxiliary drive motor of the drive wheel 2 to increase the speed of the forming drum requires limiting the maximum power of the drive motor to prevent the drum speed from exceeding the limit and causing excessive centrifugal force to drive the steel fibers to accumulate on one side of the drum wall, resulting in the separation of steel fibers from the concrete matrix and affecting the circumferential distribution of the forming effect.

[0034] The magnetic permeable component 7 used to provide the directional magnetic field can be flexibly selected, such as a copper conductive coil or a permanent magnet structure. Among them, the copper coil generates a controllable and variable magnetic field by being energized, and the magnetic field strength can be adjusted in real time. The permanent magnet structure can provide a constant magnetic field, which is simple in structure, does not require electricity, and has lower energy consumption.

[0035] The steel fiber reinforced concrete mixture can be added manually or mechanically depending on the actual production conditions. Manual addition is suitable for small-batch trial production, equipment debugging, and localized material replenishment. Automatic mechanical addition enables continuous, quantitative, and automated feeding. Both methods are compatible with this preparation process and have no impact on the fiber circumferential distribution or the quality of the concrete pipe forming. In the automatic mechanical addition method, a control system is installed. This control system is electrically connected to the steel fiber reinforced concrete slurry supply unit, the drive components of the material transport vehicle, and all drive motors, controlling the coordinated operation of each component.

[0036] When preparing steel fiber reinforced concrete pipes with large aspect ratio and ultra-long specifications, the method can add multiple sets of material transport vehicles according to the axial forming length of the pipe. The length of the forming roller is equal to the length of the concrete pipe. The pipe is segmented and moved according to the forming area, which improves the overall forming quality and production efficiency of long concrete pipes and is suitable for the industrialized mass prefabrication production of ultra-long pipes. The method of the present invention has a simple overall process flow, a high degree of automation, and is suitable for industrial mass production. It is particularly suitable for the standardized and large-scale pipeline production scenarios in prefabricated component plants, effectively replacing the laboratory small sample preparation process, overcoming the limitations of laboratory equipment, and realizing the mass prefabrication of steel fiber reinforced concrete pipelines.

[0037] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A device for preparing circumferentially distributed steel fiber concrete pipes, characterized in that, The device includes a material transport vehicle, a support frame, and a forming roller. The support frame includes fixed brackets on both sides, guide rails connecting the fixed brackets on both sides, and a height adjustment mechanism that can adjust the height of the guide rails. The two ends of the fixed brackets are mounted on the two ends of the forming roller, and the guide rails extend out along the length of the forming roller. The material transport vehicle can slide back and forth on the guide rail of the support frame; a hopper is fixedly installed on the material transport vehicle, the upper part of the hopper is a conical inlet, and the lower part is a tubular outlet. Magnetic guiding components are arranged around the tubular outlet, and the magnetic guiding components can make the steel fibers in the tubular outlet oriented along the axial direction of the tubular outlet. The size of the forming roller is adapted to the length of the concrete pipe to be processed. The forming roller rotates along its axis under external driving force, providing centrifugal force. The minimum distance between the lower end of the hopper and the inner wall of the forming roller must not be less than the maximum length of the steel fiber.

2. The apparatus according to claim 1, characterized in that, Driven surfaces that mesh with or are frictionally driven by the driving wheels are provided on both ends of the forming roller. Two driving wheels are symmetrically arranged on both sides of each driven surface, for a total of four driving wheels. Each driving wheel is driven by an independent auxiliary driving motor. All driving motors are synchronously controlled and rotate in the same direction. The driving wheels are in close contact with the outer walls of the driven surfaces at both ends of the forming roller or are driven by gear meshing. The driving motor drives the driving wheels to rotate, and the roller as a whole is driven to maintain a low roller speed by the friction or gear meshing force between the driving wheels and the forming roller. V 1. Rotate smoothly.

3. The apparatus according to claim 1, characterized in that, The magnetic permeable component is implemented by winding a magnetic permeable coil, in which case the power supply equipment for generating a magnetic field to power the coil is installed on the material transport vehicle; or it is implemented by using a ring magnet, with a ring magnet sleeved on the tubular discharge section, the ring magnet being fully fitted onto the outer surface of the tubular discharge section, the tubular discharge section being made of non-magnetic material, and a limiting part being provided at the lower part of the tubular discharge section to restrict the embedded state of the ring magnet in the tubular discharge section; if the height of the ring magnet is much smaller than the height of the tubular discharge section, multiple ring magnets are stacked along the height direction.

4. The apparatus according to claim 1, characterized in that, The conical inlet is connected to the steel fiber concrete slurry supply unit. The device also includes a control system, which is electrically connected to the steel fiber concrete slurry supply unit, the drive component of the material transport vehicle, and the drive component of the forming roller, controlling the coordinated operation of each part.

5. The apparatus according to claim 1, characterized in that, The device has multiple sets of material transport vehicles on the support frame, which are used to segment and move materials according to the pipe forming area.

6. A method for preparing a circumferentially distributed steel fiber concrete pipe, characterized in that, The preparation method uses the apparatus described in any one of claims 1-5 and includes the following steps: Step 1: Erect the support frame along the length of the forming roller. Place the material transport vehicle on the guide rail of the support frame. Fix the hopper on the material transport vehicle. The lower tubular discharge section of the hopper is located outside the guide rail. Magnetic guiding components are arranged around the tubular discharge section to pre-establish a uniform magnetic field environment that allows the steel fibers to be oriented axially along the tubular discharge section. Simultaneously, activate the drive component of the forming roller to drive the entire forming roller to maintain a low roller speed. V 1. Smooth rotation; Step 2: Add steel fiber reinforced concrete mixture to the hopper on the material transport vehicle, and control the mixture at a constant discharge rate. V 2. The material falls evenly and continuously from the hopper outlet. After the forming roller rotates once, the control system controls the material transport vehicle to automatically move forward a certain distance along the guide rail of the support frame. d The directional movement of the material transport vehicle, combined with the low-speed rotation of the forming drum, ensures that the mixture is evenly spread on all areas of the inner wall of the drum. Step 3: After the material is fed into the forming drum cavity, stop discharging material from the hopper and gradually increase the rotation speed of the forming drum. Under the continuous action of high-speed centrifugal force, the concrete mixture is tightly attached to the inner wall of the forming drum, expelling internal air bubbles and pores, and obtaining a concrete pipe with steel fibers distributed in a ring that meets the density requirements.

7. The method according to claim 6, characterized in that, V 1. No more than 60 revolutions per minute.

8. The method according to claim 6, characterized in that, Discharge rate of steel fiber reinforced concrete mixture V 2. Rotation speed of the forming roller V 1. There is a linear relationship, meaning that the time required for one revolution of the drum is 60 / V Within 1, the discharge length of the mixture is equal to the circumference of the drum 2πr, and the low drum speed of the forming drum is... V 1. Discharge rate of the mixture V 2 are respectively: ， Where r is the radius of the forming roller.

9. The method according to claim 6, characterized in that, If the concrete pipe to be processed is too long, set up several material transport vehicles to distribute the material in sections, so that the material distribution in the entire forming roller is completed before the concrete sets.

10. A steel fiber circumferentially distributed concrete pipe, characterized in that, The pipeline is prepared using the apparatus described in any one of claims 1-5, or obtained using the method described in any one of claims 6-9.

Images