High ductility concrete pole and its production process

Abstract

The application discloses a high-ductility concrete electric pole and a production process thereof, and belongs to the technical field of concrete electric poles. The base body of the electric pole is high-ductility concrete without coarse aggregate, and has strain hardening and multi-crack characteristics. A plurality of annular pads are sleeved on the main reinforcement, the outer diameter of the pads is equal to the wall thickness, and the outer circumferential surfaces of the pads are tangent to the inner surface of the hollow cavity and the outer surface of the base body respectively. The process comprises the following steps: forming a steel reinforcement framework on a steel core mold and sleeving the pads, placing the pads on two rotatable supporting rollers, so that the outer circumferential surfaces of the pads abut against the outer wall of the core mold and the surface of the supporting rollers at the same time to form a constant gap equal to the designed wall thickness; not arranging an outer mold, pumping the mixture without fluidity into the gap, and simultaneously driving the supporting rollers to rotate to drive the core mold and the framework to rotate synchronously, so that the mixture is continuously rolled and compacted to be formed, the supporting rollers are used as forming molds and extruding rollers, and the core mold is drawn out after curing to the demolding strength. The application solves the problem that the high-ductility concrete cannot be formed by the centrifugal and inner-outer mold pouring process, and the wall thickness is uniform.

Description

Technical Field

[0001] This invention belongs to the technical field of concrete poles for power transmission and transformation lines, communication and lighting, and specifically relates to a high-ductility concrete pole and its manufacturing process. Background Technology

[0002] Concrete poles are widely used supporting components in power, communication, and other infrastructure. They are mainly classified into two categories based on their reinforcement methods: prestressed concrete poles and reinforced concrete poles. Prestressed concrete poles have good crack resistance, but are brittle and have poor ductility, making them prone to brittle fracture without warning under overload conditions. Reinforced concrete poles have low cracking loads; visible cracks appear under standard load values, leading to long-term operation with cracks, allowing corrosive media to penetrate and affecting durability.

[0003] To improve the mechanical properties and durability of utility poles, researchers have explored the use of ultra-high performance concrete in pole manufacturing. The molding process mainly falls into two categories: one is internal and external mold casting, where the mixture is pumped or poured into a cavity formed by an inner and outer mold, and then compacted using vibration or vacuum treatment. The pole wall thickness is controlled by the distance between the inner and outer molds and the positioning components on the frame. The other is horizontal centrifugal molding, which relies on the centrifugal force generated by the high-speed rotation of the mold to evenly distribute and compact the mixture along the inner wall of the mold cavity.

[0004] Both of the above-mentioned processes either rely on an external mold or depend on the flow and migration of the mixture under centrifugal force. Summary of the Invention

[0005] To achieve strain hardening and multi-crack properties, high-ductility concrete contains no coarse aggregate, has a high amount of cementitious materials and a high fiber volume fraction, resulting in an extremely high viscosity and non-flowing composition that does not flow under its own weight. This type of mixture cannot be uniformly distributed and compacted on the inner wall of a high-speed rotating mold using centrifugal force, nor can it be compacted by self-leveling or vibration within a closed cavity formed by an inner and outer mold. The technical problem this invention aims to solve is: how to uniformly and densely coat and form a non-flowing high-ductility concrete around a reinforcing steel frame without relying on an outer mold, while ensuring uniform wall thickness of the steel members.

[0006] To address the aforementioned technical problems, this invention provides a high-ductility concrete pole and its manufacturing process.

[0007] According to one aspect of the present invention, a high-ductility concrete pole is provided, comprising a reinforcing steel skeleton and a concrete matrix covering the reinforcing steel skeleton. The reinforcing steel skeleton includes multiple main reinforcing bars arranged along the axial direction of the pole and helical reinforcing bars surrounding the main reinforcing bars. The concrete matrix has a hollow cavity extending along the axial direction. The concrete matrix is ​​high-ductility concrete without coarse aggregate, and the high-ductility concrete exhibits strain hardening characteristics and multi-crack characteristics under uniaxial tensile load. The standard value of the cubic compressive strength of the high-ductility concrete is greater than 50 MPa. Multiple sets of annular pads are spaced along the axial direction on the main reinforcing bars, each set containing at least two annular pads, and distributed circumferentially on the pole. The annular pads have through holes in the middle for the main reinforcing bars to pass through. The outer diameter of the annular pads is equal to the wall thickness of the concrete matrix, and the outer circumferential surface of the annular pads is tangent to the inner surface of the hollow cavity and the outer surface of the concrete matrix, respectively.

[0008] In another embodiment based on the above technical solution of the present invention, the high ductility concrete comprises, by weight: 450 to 550 parts of silicate cement, 350 to 450 parts of fly ash, 40 to 60 parts of silica fume, 350 to 450 parts of quartz sand, 180 to 220 parts of water, and 8 to 12 parts of water-reducing agent.

[0009] In another embodiment based on the above technical solution of the present invention, the high ductility concrete further includes polyethylene fibers, the length of which is 8 mm to 16 mm, and the volume content of which is 1.5% to 2.5% of the volume of the high ductility concrete.

[0010] In another embodiment based on the above technical solution of the present invention, the strength grade of the silicate cement is 52.5, the fly ash is Grade I fly ash, the particle size of the quartz sand is 40 mesh to 100 mesh, and the water-reducing agent is a polycarboxylate water-reducing agent with a water reduction rate of more than 30%.

[0011] In another embodiment based on the above technical solution of the present invention, the main reinforcing bar is a hot-rolled ribbed steel bar, the number of main reinforcing bars is 12 to 20, and the diameter of the main reinforcing bar is 10 mm to 14 mm; the spiral reinforcing bar is a cold-drawn low-carbon steel wire, the diameter of the spiral reinforcing bar is 3 mm to 5 mm, and the pitch of the spiral reinforcing bar is 60 mm to 100 mm.

[0012] In another embodiment based on the above technical solution of the present invention, the spacing between two adjacent groups of annular pads along the axial direction is 1500mm to 2500mm, the number of annular pads in each group is 2 to 10, and the annular pads in each group are evenly distributed along the circumference of the pole.

[0013] In another embodiment based on the above technical solution of the present invention, the annular pad is an ultra-high performance concrete pad, and the annular pad remains in the concrete matrix.

[0014] In another embodiment based on the above technical solution of the present invention, the pole is a tapered pole, and the wall thickness of the concrete base is 40mm to 60mm.

[0015] According to another aspect of the present invention, a manufacturing process for a high-ductility concrete pole is provided, comprising the following steps: S1. A steel reinforcement skeleton is formed on a steel core mold, the steel reinforcement skeleton including multiple main bars arranged along the axial direction of the steel core mold and spiral bars surrounding the main bars; S2. Multiple sets of annular pads are fitted on the main reinforcement at intervals along the axial direction. Each set of annular pads has at least two annular pads and they are distributed at intervals along the circumference. The outer diameter of the annular pads is equal to the design wall thickness of the pole. S3. The reinforcing steel skeleton with the steel core mold is placed on two rotatable rollers. The axes of the two rollers are parallel to the axis of the steel core mold and are located on both sides below the steel core mold. The taper of the rollers matches the taper of the pole. The outer circumferential surface of the annular pad abuts against both the outer wall of the steel core mold and the surface of the rollers, forming a constant gap between the outer wall of the steel core mold and the surface of the rollers. The constant gap is equal to the design wall thickness of the pole, and the reinforcing steel skeleton is thus positioned in the center of the constant gap. S4. Without setting an outer mold outside the steel core mold, a non-flowable high-ductility concrete mixture is pumped into the constant gap, while simultaneously driving the two idler rollers to rotate, thereby causing the steel core mold and the reinforcing steel skeleton to rotate synchronously. This allows the high-ductility concrete mixture to be continuously rolled and compacted between the outer wall of the steel core mold and the surface of the idler rollers, thus covering the reinforcing steel skeleton. The two idler rollers also serve as the forming mold and extrusion rollers for the pole. S5. After molding, a thin film is covered on the surface of the pole for curing. After the high-ductility concrete reaches the demolding strength, the steel core mold is pulled out along the axial direction.

[0016] In another embodiment based on the above technical solution of the present invention, in step S4, the equipment for pumping the high ductility concrete mixture is a screw pump or a hose extrusion pump, and the rotation speed of the two idlers is 50 r / min to 100 r / min.

[0017] In another embodiment based on the above technical solution of the present invention, in step S5, after covering with a film, the pole is left to stand still at room temperature for 20 to 28 hours; the demolding strength is 20 MPa to 30 MPa; the steel core mold is extracted at a uniform speed using a hydraulic core-pulling machine; after the steel core mold is extracted, the pole is covered with film and kept moist for 5 to 9 days, and then dried for 18 to 24 days.

[0018] Based on the high-ductility concrete pole and its production process provided in the above embodiments of the present invention, the outer forming mold is eliminated and replaced by two rotatable rollers. The rollers support the steel core mold while also serving as the forming mold and extrusion rollers for the pole. An annular pad abuts against the surface of the rollers, ensuring a constant gap equal to the designed wall thickness between the outer wall of the core mold and the surface of the rollers. The active rotation of the rollers drives the core mold and the reinforcing steel frame to rotate synchronously, and the mixture pumped into the gap repeatedly passes through the roller gap and is subjected to continuous roller pressure. This achieves the following beneficial effects: Firstly, it overcomes the molding barrier of high-ductility concrete. Roller pressing applies direct mechanical pressure, relying neither on the fluidity of the mixture itself nor on centrifugal force, thus making it suitable for high-ductility concrete mixtures with extremely high viscosity and zero slump. This directly solves the technical problem that existing centrifugal molding and internal / external mold pouring processes cannot mold high-ductility concrete.

[0019] Secondly, the pole has strong crack resistance and good durability. The standard value of the cubic compressive strength of high ductile concrete is greater than 50MPa, and no visible cracks appear on the surface of the tension zone under the load design value, thus cutting off the channel for corrosive media to invade through cracks. Its service life is much longer than that of ordinary reinforced concrete poles that have been working with cracks for a long time.

[0020] Third, it possesses high toughness and avoids brittle fracture. High-ductility concrete can continue to withstand increased tensile stress after initial cracking, forming multiple parallel fine cracks within the pole, rather than a single concentrated main crack. Therefore, the pole exhibits metal-like yielding behavior under overload, rather than the unpredictable brittle fracture of prestressed concrete poles, significantly improving safety redundancy and collapse resistance under extreme conditions.

[0021] Fourth, the wall thickness is uniform and the quality of the outer surface is controllable. The outer circumferential surface of the annular pad simultaneously abuts against the outer wall of the core mold and the surface of the roller, and the position of the steel reinforcement skeleton and the wall thickness of the rod are determined at the same time in one positioning. When the mixture exceeds the gap, it is rolled and pushed out in the circumferential and axial directions when passing through the roller gap, so the thickness of the rod is self-limited to the design value, without relying on the processing accuracy and mold closing accuracy of the outer mold.

[0022] Fifth, the equipment is simple, and the investment and operating costs are low. Compared with the centrifugal production line, this process does not require a large centrifuge and a forming mold, resulting in low energy consumption and low noise; the steel core mold can be reused, and the roller spacing can be adjusted to adapt to different specifications of poles. Attached Figure Description

[0023] The accompanying drawings, which form part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0024] The invention will be more clearly understood with reference to the accompanying drawings and the following detailed description, wherein: Figure 1 A schematic diagram of the cross-sectional structure of a high-ductility concrete pole provided in an embodiment of the present invention; Figure 2 A schematic diagram illustrating the relative positional relationship between the steel core mold, reinforcing steel frame, idler rollers, and the discharge port of the pumping equipment during the production process of high-ductility concrete poles provided in this embodiment of the invention. Figure 3 A flowchart illustrating the manufacturing process of high-ductility concrete poles provided in this embodiment of the invention.

[0025] Attached reference numerals: 1. Concrete substrate; 2. Reinforcing steel cage; 21. Main reinforcement; 22. Spiral reinforcement; 3. Annular pad; 4. Hollow cavity; 5. Steel core mold; 6. Idler roller; 7. Discharge port of pumping equipment; t. Design wall thickness. Detailed Implementation

[0026] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0027] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0028] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0029] The term "non-flowable" in this article refers to a high-ductility concrete mixture having a zero slump and not flowing or collapsing under its own weight. The term "strain hardening characteristic" refers to the material's ability to withstand increasing tensile stress and produce significant tensile deformation after initial cracking under uniaxial tensile load. The term "multi-crack characteristic" refers to the formation of multiple parallel, fine cracks within the material during the aforementioned deformation process, rather than a single, concentrated main crack.

[0030] In one embodiment, refer to Figure 1The high-ductility concrete pole includes a steel reinforcement cage 2 and a concrete matrix 1 covering the steel reinforcement cage 2. The steel reinforcement cage 2 includes multiple main bars 21 arranged along the pole's axial direction and spiral bars 22 surrounding the main bars 21. The concrete matrix 1 has an axially penetrating hollow cavity 4, which is formed after the steel mandrel 5 is removed.

[0031] In one embodiment, the main reinforcement 21 is made of 16 HRB500 grade hot-rolled ribbed steel bars with a diameter of 12mm, which are evenly arranged along the circumference of the pole; the spiral reinforcement 22 is made of cold-drawn low-carbon steel wire with a diameter of 4mm and a pitch of 80mm, which is wrapped around and welded to the outside of the main reinforcement 21.

[0032] In one embodiment, refer to Figure 1 Annular pads 3 are installed every 2000mm along the length of the pole, with eight pads in each group. Each pad is fitted onto a spaced-apart main reinforcing bar 21 through a central through-hole; that is, one annular pad 3 is fitted onto every two main reinforcing bars 21. The annular pad 3 is a high-performance concrete pad, disc-shaped, with an outer diameter equal to the designed wall thickness t of the concrete matrix 1. In this embodiment, t is 50mm. After the annular pad 3 is fitted in place, its outer circumference is tangent to both the inner surface of the hollow cavity 4 and the outer surface of the concrete matrix 1, thus positioning the main reinforcing bar 21 at the center of the wall thickness. The thickness of both the inner and outer protective layers is half of t.

[0033] The annular pads 3 are not required to be installed on every main reinforcing bar 21. For positioning and thickness limiting, at least two annular pads 3 are needed per group: when two are installed per group, the two annular pads 3 are arranged radially opposite each other on the pole, i.e., 180 degrees apart circumferentially. Their outer circumferential surfaces abut against the outer wall of the steel core mold 5 and the surface of the roller 6 at opposite ends of the same diameter, thus constraining the reinforcing bar skeleton 2 in this diametrical direction. When the roller 6 rotates the steel core mold 5 and the reinforcing bar skeleton 2, this constraint direction continuously sweeps across the entire circumference, thus maintaining a constant gap between the steel core mold 5 and the roller 6. When four are installed per group, the four annular pads 3 are distributed circumferentially at 90-degree intervals; when eight are installed per group, one of every two main reinforcing bars 21 is fitted with an annular pad 3, as shown below. Figure 1 As shown.

[0034] Increasing the number of annular blocks 3 in each group can reduce the local thickness deviation of the pole body between two adjacent annular blocks 3 and make the positioning of the reinforcing steel cage 2 more stable; reducing the number can reduce the amount of blocks used and the workload of the installation process. In actual production, the number of blocks can be selected within the above range according to the length of the pole, the rigidity of the reinforcing steel cage 2, and the wall thickness accuracy requirements. In addition, each group of annular blocks 3 is not limited to being evenly distributed along the circumference. As long as at least two annular blocks 3 are spaced apart from each other in the circumference, they can simultaneously constrain the position of the reinforcing steel cage 2 relative to the steel core mold 5 and the roller 6 during the forming process.

[0035] Because the annular pad 3 needs to be pressed against the surface of the roller 6 during the molding process, its outer circumference is tangent to the outer surface of the pole and partially exposed after molding, and remains in the concrete matrix 1 to form a component of the pole body. Using ultra-high performance concrete to make the annular pad 3 can match its strength, elastic modulus and durability with the concrete matrix 1, avoiding the formation of weak points at the interface between the two due to material differences.

[0036] In one embodiment, the concrete matrix 1 is a high-ductility concrete without coarse aggregate, comprising, by weight: 500 parts of P·O 52.5 silicate cement, 400 parts of Grade I fly ash, 50 parts of silica fume, 400 parts of quartz sand with a particle size of 40 to 100 mesh, 200 parts of water, and 10 parts of polycarboxylate superplasticizer with a water reduction rate greater than 30%; and polyethylene fiber with a length of 12 mm is also incorporated, with its volume content being 2.0% of the volume of the high-ductility concrete.

[0037] In the above proportions, fly ash accounts for approximately 42% of the total cementitious material, and the water-cement ratio is approximately 0.21. The absence of coarse aggregate and the use of a high fly ash content are necessary conditions for the matrix to achieve strain hardening and multi-crack properties; however, this composition also results in extremely high viscosity and zero slump of the mixture, making centrifugal molding and internal / external mold casting processes unsuitable.

[0038] In one embodiment, refer to Figure 2 and Figure 3 The production process of high-ductility concrete poles includes the following steps.

[0039] Step S1: Prepare the steel mandrel 5 and form the reinforcing steel frame 2. Clean the steel mandrel 5 and apply a thin layer of release agent to its outer wall. In this embodiment, the steel mandrel 5 is 12m long, and its outer contour is a conical surface consistent with the taper of the pole being produced. Arrange 16 main reinforcing bars 21 evenly along the circumference of the steel mandrel 5, and then wrap spiral reinforcing bars 22 around the outside of the main reinforcing bars 21 with a pitch of 80mm and weld them in place to form the reinforcing steel frame 2.

[0040] Step S2: Install the annular spacers 3. A set of eight annular spacers 3 are installed every 2000mm along the length of the pole, and are fitted onto a spaced-apart main reinforcing bar 21 through a central through-hole. The outer diameter of the annular spacer 3 is equal to the designed wall thickness of the pole, which is 50mm in this embodiment.

[0041] Step S3, Roller Placement. The entire steel reinforcement frame 2 with the steel core mold 5 is hoisted onto two rotatable rollers 6. The axes of the two rollers 6 are parallel to the axis of the steel core mold 5 and are positioned on either side below the steel core mold 5. The taper of the rollers 6 matches the taper of the pole, ensuring a consistent gap along the entire length of the pole. The distance between the two rollers 6 is adjusted so that the outer circumference of the annular pad 3 simultaneously abuts against the outer wall of the steel core mold 5 and the surface of the rollers 6. At this point, a constant gap of 50mm is formed between the outer wall of the steel core mold 5 and the surface of the rollers 6. This gap is the design wall thickness t of the pole, and the steel reinforcement frame 2 is thus positioned at the center of this gap.

[0042] Step S4, pumping and roll forming. Without any external mold outside the steel core mold 5, the pumping equipment is started, and the well-mixed high-ductility concrete mixture is continuously and evenly fed into the constant gap via the discharge port 7. In this embodiment, a screw pump is used as the pumping equipment; both the screw pump and the hose extrusion pump are positive displacement pumps, which have good transport adaptability for mixtures with high viscosity and high fiber content, and will not cause fiber agglomeration due to shearing. The discharge port 7 moves back and forth along the axial direction of the steel core mold 5 with the traveling mechanism, so that the mixture is evenly distributed along the entire length of the pole. At the same time, the rotation drive device of the idler rollers 6 is started, causing the two idler rollers 6 to rotate actively, and through the annular pad 3 and the already formed pole surface, driving the steel core mold 5 and the reinforcing steel skeleton 2 to rotate synchronously, with the rotation speed controlled between 60 r / min and 80 r / min.

[0043] During rotation, the mixture is carried by the rotation of the steel mandrel 5 to the gap formed by the outer wall of the steel mandrel 5 and the surface of the support roller 6. It is then subjected to continuous rolling pressure, compacting and encapsulating the reinforcing steel skeleton 2, while simultaneously expelling any trapped air. Because the annular pad 3 defines the minimum gap, any mixture exceeding this gap is rolled and pushed away circumferentially and axially as it passes through the gap, thus limiting the thickness of the rod to the designed wall thickness. As rotation continues, the outer surface of the rod is repeatedly rolled by the support roller 6, becoming smooth and dense. Here, the two support rollers 6 simultaneously perform two functions: firstly, to replace the outer mandrel and define the outer contour of the rod; secondly, to act as extrusion rollers and provide compaction pressure.

[0044] Step S5, Curing and Demolding. Immediately after molding, cover the surface of the pole blank with a polyethylene film for moisturizing and curing, and let it stand at room temperature for 24 hours. After the compressive strength of the test block cured under the same conditions reaches the demolding strength of 25 MPa, use a hydraulic core-pulling machine to slowly and uniformly pull the steel core mold 5 out of the pole along the axial direction. The cavity left after extraction is the hollow cavity 4. After demolding, the pole continues to be covered with film for moisturizing and curing under natural conditions for 7 days, and then dry-cured for 21 days before being shipped out.

[0045] The mechanical properties of the poles prepared in the above embodiments were tested according to the method specified in GB / T 4623-2025 "Circular Concrete Poles". When loaded to the cracking test moment specified in the standard, no visible cracks appeared on the surface of the tension zone of the pole, meaning the pole did not crack under the design load. When the load was further increased to 2.0 times the cracking test moment, the pole reached its maximum bearing capacity. At failure, the surface of the pole showed multiple parallel fine cracks, with a maximum crack width of 0.05 mm. No concentrated main cracks formed, and no brittle fracture occurred, exhibiting significant ductility. Concrete test blocks cured under the same conditions as the poles showed a 28-day cubic compressive strength of 82 MPa.

[0046] It can be seen that the pole in the above embodiment simultaneously achieves the two objectives of not cracking under the load design value and high toughness to prevent brittle fracture; at the same time, since the thickness of the pole body is automatically limited by the roller gap defined by the annular pad 3 during the forming process, the pole body wall thickness is uniform and the outer circular surface is smooth and dense after being repeatedly rolled by the roller 6, without relying on the processing accuracy and mold closing accuracy of the outer mold.

[0047] Those skilled in the art should understand that the above embodiments are merely examples, and various modifications can be made without departing from the concept of this application. In other embodiments, polyethylene fibers can be replaced with other polymer fibers with high elastic modulus and high elongation at break, such as polyvinyl alcohol fibers, or a mixture of the above fibers can be used, as long as the resulting matrix exhibits strain hardening characteristics and multi-crack features under uniaxial tensile load.

[0048] In other embodiments, in addition to screw pumps and hose extrusion pumps, any volumetric pumping equipment capable of continuously and stably conveying high-viscosity mixtures with zero slump can be used; the discharge port 7 can either reciprocate along the axial direction of the pole with the traveling mechanism, or multiple ports can be spaced apart along the axial direction to distribute material simultaneously.

[0049] In other embodiments, the number of rollers 6 is preferably two; when the pole is long, multiple pairs of rollers 6 can be arranged along the axial direction to reduce the deflection of the steel mandrel 5, and the spacing between each pair of rollers 6 should be kept consistent so that the gap is constant along the entire length.

[0050] In other embodiments, the annular pad 3 may also be prefabricated using high-ductility concrete of the same material as the concrete substrate 1 to further reduce the interface difference between it and the substrate; the spacing between the groups and the number of each group can be adjusted within the range defined in the claims according to the length and stiffness requirements of the pole.

[0051] In other embodiments, this process is applicable to both tapered poles and poles of equal diameter; when used for poles of equal diameter, the idler roller 6 is a cylindrical idler roller, and the remaining steps are the same.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-ductility concrete pole, comprising a steel reinforcement cage and a concrete matrix covering the steel reinforcement cage, wherein the steel reinforcement cage includes multiple main bars arranged along the axial direction of the pole and helical bars surrounding the main bars, and the concrete matrix has a hollow cavity extending along the axial direction, characterized in that: The concrete matrix is ​​a high-ductility concrete without coarse aggregate. The high-ductility concrete exhibits strain hardening characteristics and multi-crack characteristics under uniaxial tensile load. The standard value of the cubic compressive strength of the high-ductility concrete is greater than 50 MPa. Multiple sets of annular pads are fitted on the main rib at intervals along the axial direction, with each set containing at least two annular pads, and they are distributed at intervals along the circumference of the pole. The annular pad has a through hole in the middle for the main reinforcement to pass through. The outer diameter of the annular pad is equal to the wall thickness of the concrete matrix, and the outer circumferential surface of the annular pad is tangent to the inner surface of the hollow cavity and the outer surface of the concrete matrix, respectively.

2. The high-ductility concrete pole according to claim 1, characterized in that, The high-ductility concrete comprises, by weight, 450 to 550 parts of silicate cement, 350 to 450 parts of fly ash, 40 to 60 parts of silica fume, 350 to 450 parts of quartz sand, 180 to 220 parts of water, and 8 to 12 parts of water-reducing agent.

3. The high-ductility concrete pole according to claim 2, characterized in that, The high-ductility concrete also includes polyethylene fibers, the length of which is 8 mm to 16 mm, and the volumetric content of which is 1.5% to 2.5% of the volume of the high-ductility concrete.

4. The high-ductility concrete pole according to claim 2, characterized in that, The silicate cement has a strength grade of 52.5, the fly ash is Grade I fly ash, the quartz sand has a particle size of 40 to 100 mesh, and the water-reducing agent is a polycarboxylate water-reducing agent with a water reduction rate of more than 30%.

5. The high-ductility concrete pole according to claim 1, characterized in that, The main reinforcing bars are hot-rolled ribbed steel bars, with 12 to 20 bars and a diameter of 10 mm to 14 mm; the spiral reinforcing bars are cold-drawn low-carbon steel wires, with a diameter of 3 mm to 5 mm and a pitch of 60 mm to 100 mm.

6. The high-ductility concrete pole according to claim 1, characterized in that, The spacing between two adjacent groups of annular pads along the axial direction is 1500mm to 2500mm, the number of annular pads in each group is 2 to 10, and the annular pads in each group are evenly distributed along the circumference of the pole.

7. The high-ductility concrete pole according to claim 6, characterized in that, The annular pad is an ultra-high performance concrete pad, and the annular pad remains within the concrete matrix.

8. The high-ductility concrete pole according to claim 1, characterized in that, The pole is a tapered pole, and the wall thickness of the concrete base is 40mm to 60mm.

9. A manufacturing process for a high-ductility concrete pole, characterized in that, Includes the following steps: S1. A steel reinforcement skeleton is formed on a steel core mold, the steel reinforcement skeleton including multiple main bars arranged along the axial direction of the steel core mold and spiral bars surrounding the main bars; S2. Multiple sets of annular pads are fitted on the main reinforcement at intervals along the axial direction. Each set of annular pads has at least two annular pads and they are distributed at intervals along the circumference. The outer diameter of the annular pads is equal to the design wall thickness of the pole. S3. The reinforcing steel skeleton with the steel core mold is placed on two rotatable rollers. The axes of the two rollers are parallel to the axis of the steel core mold and are located on both sides below the steel core mold. The taper of the rollers matches the taper of the pole. The outer circumferential surface of the annular pad abuts against both the outer wall of the steel core mold and the surface of the rollers, forming a constant gap between the outer wall of the steel core mold and the surface of the rollers. The constant gap is equal to the design wall thickness of the pole, and the reinforcing steel skeleton is thus positioned in the center of the constant gap. S4. Without setting an outer mold outside the steel core mold, a non-flowable high-ductility concrete mixture is pumped into the constant gap, while simultaneously driving the two idler rollers to rotate, thereby causing the steel core mold and the reinforcing steel skeleton to rotate synchronously. This allows the high-ductility concrete mixture to be continuously rolled and compacted between the outer wall of the steel core mold and the surface of the idler rollers, thus covering the reinforcing steel skeleton. The two idler rollers also serve as the forming mold and extrusion rollers for the pole. S5. After molding, a thin film is covered on the surface of the pole for curing. After the high-ductility concrete reaches the demolding strength, the steel core mold is pulled out along the axial direction.

10. The manufacturing process of the high-ductility concrete pole according to claim 9, characterized in that, In step S4, the equipment for pumping the high-ductility concrete mixture is a screw pump or a hose extrusion pump, and the rotation speed of the two idlers is 50 r / min to 100 r / min; and / or In step S5, after covering with a film, the pole is left to stand still at room temperature for 20 to 28 hours; the demolding strength is 20 MPa to 30 MPa; the steel core mold is extracted at a uniform speed using a hydraulic core-pulling machine; after the steel core mold is extracted, the pole is covered with film for 5 to 9 days for moisture retention and then left to dry for 18 to 24 days.

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