A method for preparing high-strength concrete poles

Abstract

This application relates to the field of concrete product molding technology, specifically disclosing a method for preparing high-strength concrete poles. Addressing the problems of low material utilization in existing homogeneous poles and weak interfacial bonding and easy material migration in gradient poles, this pole is divided into three stress zones (strong, medium, and weak) along the axial direction. A differentiated concrete mix ratio is adopted, and a gradient synergistic blending system of activated ceramic waste powder is constructed. An interfacial transition layer is set between adjacent functional zones. The preparation method includes gradient formula design, reinforcement cage and mold preparation, axial stepped material distribution, bidirectional graded centrifugal molding, stepped tensioning and synergistic curing, and post-processing and natural curing of the finished product. This application significantly improves the ultimate bending capacity and interfacial bonding strength of the pole through dual interfacial strengthening and zoned anti-material migration technology, while simultaneously achieving high-value utilization of industrial solid waste, reducing production costs. The process is simple and compatible with existing industrial production equipment, showing good application prospects.

Description

Technical Field

[0001] This application relates to the field of concrete product molding technology, and more specifically, it relates to a method for preparing a high-strength concrete pole. Background Technology

[0002] Ring-shaped concrete poles are the most widely used foundation support components in power and communication line engineering. They are extensively used in urban and rural power grid construction and renovation, communication base station erection, and municipal lighting projects. Exposed to complex outdoor environments for extended periods, they must continuously withstand alternating loads such as wind loads, icing loads, and line tension. Their mechanical properties and service life directly determine the operational safety and reliability of the line system. Currently, the industry generally adopts a design approach using homogeneous concrete mix proportions and standardized reinforcement throughout the pole. The production process is mature, and the equipment is highly versatile, meeting the needs of conventional operating conditions.

[0003] However, traditional homogeneous pole design cannot match the inherent differences in axial bending moment distribution, resulting in insufficient strength reserves in high-stress areas and significant material waste in low-stress areas. Current technologies often use industrial solid waste by uniformly replacing fine aggregates or uniformly adding active admixtures throughout the pole, making it difficult to differentiate utilization based on the axial stress differences. Increasing the amount of solid waste reduces the strength in high-stress areas, while decreasing the amount limits the amount of solid waste that can be disposed of. This creates a technical contradiction between balancing mechanical properties and resource utilization, hindering the green and low-carbon development of concrete poles. Summary of the Invention

[0004] To address the problem that traditional homogeneous concrete poles cannot match axial bending moment distribution and thus cannot simultaneously improve mechanical properties and achieve high-value utilization of industrial solid waste, this application provides a method for preparing high-strength concrete poles.

[0005] A method for preparing a high-strength concrete utility pole includes the following steps: S1. Gradient Formula Design: Based on the axial force distribution of the pole, the pole is divided into a strong force zone, a medium force zone and a weak force zone along the axial direction. Differentiated concrete mix proportions are designed for each functional zone to construct a gradient synergistic blending system of activated ceramic waste powder, and an interface transition layer is set between adjacent functional zones. S2. Preparation of steel cage and mold: Prepare steel cage, set up a partitioned high-frequency vibrator on the inner wall of the centrifugal steel mold, and spray the carbonized seed slurry obtained by carbonation treatment of centrifugal residue to form a seed interface layer. S3, Axial stepped concrete placement: In the order from root to tip, concrete in the strong stress zone, the first interface transition concrete, the medium stress zone, the second interface transition concrete and the weak stress zone are injected into the mold in sequence. After each area is placed, the corresponding high-frequency vibrator is started for pre-compaction. S4. Two-way graded centrifugal molding: A two-way centrifugal system with alternating forward and reverse rotation is adopted. Combined with the dynamic matching of the speed difference and the water-cement ratio of concrete in each functional area, as well as the coordinated vibration of each zone, the compact molding of concrete is completed. S5. Staged tensioning and coordinated curing: After demolding, the prestressed main reinforcement is subjected to initial tensioning and normal pressure static curing, secondary tensioning and constant temperature and humidity curing, release tension and residual stress control, high pressure final curing and hydration coordinated vibration to complete the dynamic matching of prestress establishment and concrete strength growth. S6. Finished product post-processing and natural curing: End caps are applied to both ends of the poles, waterproofing agent is applied to the outer surface, and the poles are sent to the storage yard for natural curing.

[0006] By adopting the above technical solutions, the traditional design concept of homogeneous concrete poles is broken, and a precise correspondence between material properties and axial bending moment distribution is established. The problem of material slippage in gradient poles is solved from the root by axial stepped material distribution combined with zoned independent vibration control. The spatial distribution of fibers in the matrix is ​​optimized by combining forward and reverse bidirectional centrifugal technology. The process of step tensioning and curing is deeply integrated to achieve synchronous matching between prestress establishment and concrete strength development. At the same time, the centrifugal residue and ceramic waste activation tail gas generated during the production process are converted into interface strengthening materials in situ, forming a complete solid waste closed-loop utilization system of ceramic waste activation - tail gas utilization - residue modification - interface strengthening.

[0007] Preferably, in step S1, the strong stress zone accounts for 25-35% of the total length of the rod, the medium stress zone accounts for 45-55% of the total length of the rod, and the weak stress zone accounts for 15-25% of the total length of the rod; the axial thickness of the interface transition layer is 50-80mm.

[0008] By adopting the above technical solution, the length ratio of the functional area is determined based on the standard bending moment envelope diagram of a 12m tapered pole. The strong stress area completely covers the root region where the pole experiences the maximum bending moment, the medium stress area corresponds to the middle region where the bending moment changes linearly, and the weak stress area corresponds to the tip region where the bending moment is low. The interface transition layer eliminates the interface stress concentration caused by the abrupt change in elastic modulus between adjacent functional areas through the gradual change in concrete properties.

[0009] Preferably, in step S1, the concrete mix proportions for each functional area are based on 100 parts by weight. Based on silicate cement: The high-stress zone comprises 100 parts cement, 25-30 parts silica fume, 15-20 parts S95 grade mineral powder, 180-220 parts aggregate, 0.8-1.2 parts hook-shaped steel fiber, 0.15-0.2 parts polypropylene coarse fiber, a water-cement ratio of 0.18-0.19, and a polycarboxylate superplasticizer dosage of 1.2-1.5% of the total mass of the cementitious materials. The intermediate stress zone comprises 85-90 parts cement, 25-30 parts silica fume, 15-20 parts S95 grade mineral powder, 10-15 parts activated ceramic waste powder, 200-240 parts aggregate, 0.5-0.8 parts end-hook steel fiber, 0.1-0.15 parts polypropylene coarse fiber, a water-cement ratio of 0.19-0.20, and a polycarboxylate superplasticizer dosage of 1.0-1.3% of the total mass of the cementitious materials. The weak stress zone comprises 75-80 parts cement, 25-30 parts silica fume, 15-20 parts S95 grade mineral powder, 20-25 parts activated ceramic waste powder, 120-160 parts aggregate, 0.2-0.3 parts coarse polypropylene fiber, 0.1-0.15 parts fine polypropylene fiber, a water-cement ratio of 0.20-0.21, and a polycarboxylate superplasticizer dosage of 0.8-1.1% of the total mass of the cementitious materials.

[0010] By adopting the above technical solution, a dual-gradient system of active cementitious material and fiber reinforcement is constructed. In the high-stress zone, a highly active pure cement-based cementitious system and a high dosage of end-hook steel fibers are used to ensure the ultimate bearing capacity of the pole. In the medium and weak stress zones, the dosage of activated ceramic waste powder is gradually increased to replace cement, and its secondary pozzolanic reaction generates hydrated calcium silicate and hydrated calcium aluminate to supplement the later strength of the concrete. The type and dosage of fibers are adjusted according to the stress requirements. End-hook steel fibers mainly improve tensile and flexural properties. The coarse polypropylene fibers with a diameter of 0.3-0.5 mm are used to improve the toughness of the matrix, and the fine polypropylene fibers with a diameter of 0.1-0.2 mm are used to inhibit early shrinkage cracks in the concrete.

[0011] Preferably, the aggregate in the high-stress zone is composed of a mixture of quartz sand and basalt crushed stone with a particle size of 5-10 mm at a weight ratio of 0.6-0.8:1; the aggregate in the medium-stress zone is composed of a mixture of quartz sand and basalt crushed stone with a particle size of 5-10 mm at a weight ratio of 0.9-1.1:1; and the aggregate in the weak-stress zone is pure quartz sand.

[0012] By adopting the above technical solutions, the gradient optimization of aggregate composition is achieved. In the high-stress zone, high-content basalt crushed stone is used to improve the compressive strength and elastic modulus of concrete by utilizing its high hardness and high elastic modulus. In the medium-stress zone, an equal proportion of sand and gravel is used to balance the strength and workability of concrete. In the weak-stress zone, all-quartz sand aggregate is used to reduce the apparent density of concrete, reduce the self-weight of the pole tip, and improve the deformation coordination ability of concrete.

[0013] Preferably, in step S2, the preparation of the steel cage includes: the prestressed main reinforcement ratio in the strong stress zone is 40-60% higher than that in the weak stress zone; the spacing of the spiral reinforcement in the strong stress zone is 45-55% denser than that in the medium stress zone and the weak stress zone; the spacing of the spiral reinforcement within 1.4-1.5m at both ends of the pole is 60-80mm; and the spacing of the spiral reinforcement in the middle section is 90-110mm.

[0014] By adopting the above technical solutions, the coordinated gradient design of the steel cage reinforcement and concrete strength is achieved. The reinforcement ratio of the main reinforcement matches the tensile bearing capacity requirements of each area. The gradient change in the spacing of the spiral reinforcement provides different degrees of lateral restraint, improving the shear strength and ductility of the concrete. The spiral reinforcement at both ends of the pole is densified to improve the anchorage performance and splitting resistance of the end concrete, preventing splitting failure of the end concrete during tensioning and use.

[0015] Preferably, in step S2, the method for preparing the carbonated seed slurry is as follows: collect the residual slurry discharged after centrifugal molding, introduce the tail gas generated during the wet heat activation process of ceramic waste into the residual slurry for carbonation treatment for 10-15 minutes to generate calcium carbonate crystal nuclei; spray the obtained seed slurry onto the inner wall of the steel mold and the outer edge of the reinforcing cage to form a seed interface layer with a thickness of 0.3-0.5 mm.

[0016] By adopting the above technical solution, the unhydrated cement particles remaining in the centrifugal slurry are used as a carrier. Carbon dioxide-rich ceramic waste is introduced to activate the tail gas, and calcium carbonate crystal nuclei with a particle size of 50-100nm are generated in situ. The seed slurry is uniformly sprayed onto the surface of the mold and the reinforcing cage using a high-pressure airless spraying method. These nanocrystal nuclei can serve as preferential hydration nucleation sites for subsequent concrete pouring, inducing synchronous hydration of concrete and matrix at the interface and eliminating the weak interface transition zone between new and old concrete.

[0017] Preferably, in step S2, immediately after the carbonated seed slurry is sprayed, a layer of short-cut basalt fibers with a length of 6-12 mm is uniformly spread in the interface region corresponding to the interface transition layer described in step S1, with a spreading amount of 0.2-0.4 kg / m². 2 The short-cut basalt fibers are partially embedded in the seed crystal interface layer; after the seed crystal interface layer has initially solidified, a release agent is applied.

[0018] By adopting the above technical solution, short-cut basalt fibers are evenly spread using a hand-held spreader before the seed slurry initially sets, so that 1 / 3 to 2 / 3 of the fiber length is embedded in the uncured slurry to form a mechanical anchor. After the subsequent concrete is poured, it completely wraps the fibers, and the fibers can cross the interface to form a continuous physical bridging structure. At the same time, the three-dimensional network formed by the fibers at the interface can effectively block the axial flow of aggregate and cement slurry during centrifugation.

[0019] Preferably, in step S4, the specific process of the bidirectional graded centrifugal molding is as follows: Low-speed material feeding stage: The mold rotates forward at a speed of 180-220 r / min for 2-3 minutes, and the high-frequency vibrator is turned on throughout the entire process. Medium-speed transition stage: The mold first rotates forward at 350-400 r / min for 1-1.2 min, then rotates in reverse at a speed 8-12% higher than the forward speed for 1-1.2 min. Only the high-frequency vibrator in the high-stress area is activated. For every 0.01 decrease in the water-to-glue ratio, the difference between the forward and reverse rotation speeds increases by 1-1.2%. High-speed compaction stage: The mold rotates in the forward direction, adopting a three-stage stepped speed increase. The initial speed is 380-420 r / min, each stage increases by 50 r / min and is maintained for 2 minutes, and the final speed is 520-620 r / min. The total duration is 6-8 minutes. Only the high-frequency vibrator in the high-stress area is turned on and the frequency increases synchronously with the speed.

[0020] By adopting the above technical solution, a three-stage graded centrifugal system is used. In the low-speed stage, the entire stage is vibrated to ensure uniform initial concrete distribution and avoid local material shortages. In the medium-speed stage, the alternating forward and reverse rotation cancels out the radial orientation of the fibers caused by unidirectional centrifugation, so that the fibers form a three-dimensional random distribution in the matrix. At the same time, the speed difference is dynamically adjusted with the water-cement ratio. The lower the water-cement ratio, the worse the concrete fluidity. The speed difference is increased accordingly to ensure the compaction effect. In the high-speed stage, only the vibrator in the high-stress area is turned on to specifically improve the concrete density in the high-load area.

[0021] Preferably, in step S5, the specific system for staged tensioning and coordinated curing is as follows: Initial tensioning and static curing at normal pressure: Apply 28-32% of the design tensioning control stress to the prestressed main reinforcement and temporarily lock it. Heat it at a constant rate of 8-12℃ / h to 58-62℃ and statically cure it at normal pressure for 2.8-3.2h. Secondary tensioning and constant temperature and humidity: The tensioning is increased to 100% of the design tension control stress and permanently locked. The tensioning process adopts a dual control mode of stress value and elongation value. The tension stress deviation is no more than 1%, and the elongation value deviation is no more than ±1%. The temperature is uniformly increased to 85-95℃ at a rate of 14-16℃ / h and then kept at constant temperature and humidity for 7-9 hours. Tensioning and residual stress control: After demolding, apply a reverse top pressure of 20-25% of the design tension control stress to the end of the steel cage in the high-stress area of ​​the pole, hold for 25-35 seconds, and then unload. High-pressure final curing and hydration vibration: The pressure is increased uniformly to 0.8-1.2MPa and 175-185℃ at a rate of 0.2-0.4MPa / h, and the temperature and pressure are kept constant for 5-7h. During this period, axial low-frequency vibration is performed once every 1.8-2.2h, with a frequency of 15-20Hz and a single vibration duration of 0.8-1.2min.

[0022] By adopting the above technical solution, the tensioning process and the curing process are deeply integrated. The initial tensioning is carried out when the concrete compressive strength reaches 30% of the design strength to prevent early shrinkage cracking. Static curing at normal pressure allows the concrete to gain initial strength and complete most of the early shrinkage. The secondary tensioning is carried out when the concrete compressive strength reaches 70% of the design strength, effectively reducing the prestress loss caused by later shrinkage and creep of the concrete. After release, reverse top pressure releases the residual tensile stress at the end of the steel cage in the high-stress zone. The axial low-frequency vibration in the high-pressure final curing stage can expel residual air bubbles inside the concrete, promote the uniform distribution of hydration products, and refine the internal pore structure of the concrete.

[0023] Preferably, in step S6, the post-processing and natural curing of the finished product specifically involves: sealing the inner cavity of the pole with micro-expansion cement mortar at both ends, uniformly applying 1-2 coats of water-based nano-silicon waterproofing agent to the outer surface, and naturally curing it in the storage yard for 12-16 days, during which time water is sprayed 1-3 times a day to keep the surface of the pole continuously moist.

[0024] By adopting the above technical solutions, the inner cavity of the pole is sealed with micro-expansion cement mortar with a strength grade of not less than C40 to prevent moisture and harmful gases from entering the pole and corroding the steel bars; a water-based nano-silicon waterproofing agent with a solid content of 20%-30% is applied to penetrate into the concrete surface to a depth of 3-5mm to form a water-repellent layer, blocking the intrusion channels of external moisture; and a reasonable natural curing system ensures the continuous and stable growth of the concrete strength in the later stage, improving the long-term service performance of the pole.

[0025] In summary, this application has the following beneficial effects: 1. This application adopts an axial gradient formulation design, which divides the pole into three functional zones (strong, medium, and weak) according to the axial force distribution and designs differentiated concrete mix proportions to construct a gradient synergistic blending system of activated ceramic waste powder. At the same time, an interface transition layer is set between adjacent functional zones to achieve precise matching between material properties and stress requirements, improve the overall mechanical properties of the pole, and realize the high-value utilization of industrial solid waste.

[0026] 2. In this application, a dual interface strengthening technology combining carbonated seed slurry with short-cut basalt fibers is preferred. Seed slurry is prepared by using centrifugal residue and activated tail gas from ceramic waste to induce synchronous hydration of the interface. Combined with the physical bridging effect of short-cut basalt fibers, the interface bonding strength between different functional zones is significantly improved, while preventing axial movement of aggregate during centrifugation.

[0027] 3. The method of this application combines independent control of zoned high-frequency vibrators with bidirectional graded centrifugal molding. When material is placed in each zone, only the vibrator of the corresponding zone is activated. At the same time, the centrifugal system of alternating forward and reverse rotation is adopted and the speed difference and water-cement ratio are dynamically matched to effectively prevent the cross-contamination of different concrete formulas and ensure the uniform density of the concrete throughout the pole.

[0028] 4. The method of this application, through a staged tensioning and synergistic curing process, sequentially performs initial tensioning and static curing under normal pressure, secondary tensioning and constant temperature and humidity, release and residual stress control, and high-pressure final curing and hydration synergistic vibration, to achieve dynamic matching between prestress establishment and concrete strength growth, effectively reducing prestress loss caused by concrete shrinkage and creep.

[0029] 5. The method of this application, by optimizing the post-processing and natural curing of finished products, uses micro-expansion cement mortar to seal the inner cavity of the pole and applies water-based nano-silicon waterproofing agent, combined with a reasonable yard watering and curing system, effectively improves the impermeability and long-term service durability of the pole. Attached Figure Description

[0030] Figure 1 This is a flowchart of a method for preparing a high-strength concrete pole provided in this application. Detailed Implementation

[0031] The present application will be further described in detail below with reference to embodiments and comparative examples. Unless otherwise specified, the experimental methods used below are conventional methods. Unless otherwise specified, the materials, reagents, methods and instruments used are all conventional materials, reagents, methods and instruments in the art, which can be obtained by those skilled in the art through commercial channels or prepared according to literature methods.

[0032] Technical Concept: Currently, most ring-shaped concrete poles adopt a design with homogeneous concrete throughout, which cannot match the differences in axial bending moment distribution, resulting in insufficient strength in high-stress areas and serious material waste in weak-stress areas. Existing gradient pole technology has two major pain points: low interface bonding strength and centrifugal material migration. The asynchronous hydration of new and old concrete at the interface creates a weak transition zone, and the axial transmission of vibration energy causes different concrete formulations to mix, completely destroying the gradient structure. In addition, existing technologies often use the method of uniformly adding industrial solid waste throughout the pole, which cannot balance the mechanical properties of the pole with the amount of solid waste disposal. Traditional one-time tensioning and curing processes also have problems such as large prestress loss and poor crack resistance.

[0033] This technical solution first constructs a gradient synergistic blending system of activated ceramic waste powder based on the axial stress distribution of the pole, achieving a precise match between material properties and stress requirements. Second, it uses centrifugal residue and activated tail gas from ceramic waste to prepare carbonated seed slurry in situ, combined with interfacial spreading of short-cut basalt fibers to form a dual interfacial reinforcement system of chemical induction and physical bridging. Simultaneously, it employs zoned independent vibration control combined with bidirectional centrifugal processes of forward and reverse rotation to effectively solve the problem of centrifugal material leakage and optimize fiber spatial distribution. Finally, through a process that deeply integrates staged tensioning and curing, it achieves a dynamic match between prestress establishment and concrete strength growth, comprehensively improving the overall performance and environmental benefits of the pole.

[0034] Preparation Example 1: The preparation method of activated ceramic waste powder is as follows: Take ceramic polishing waste from a building ceramics factory, remove iron by magnetic separation, place it in a rotary dryer, dry it at 105℃ until the moisture content is ≤1%, and then transfer it to a ball mill to grind it until the specific surface area is ≥450m². 2 / kg, ceramic waste slag powder was obtained; the ceramic waste slag powder and quicklime were mixed evenly in a double spiral mixer at a mass ratio of 100:4, and then transferred to a closed high-pressure reactor. Saturated water steam was introduced, and the mixture was activated under humid heat conditions of 165℃ and 0.55MPa for 2.5h. After naturally cooling to room temperature, the activated ceramic waste slag powder was discharged. Its 28-day activity index was determined according to GB / T17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)" and was ≥85%.

[0035] Example 1: This example provides a method for preparing a high-strength concrete pole, including the following steps: S1. Gradient Formula Design: Based on the axial force distribution of the pole, the pole is divided into a strong force zone, a medium force zone, and a weak force zone along the axial direction. Differentiated concrete mix proportions are designed for each functional zone to construct a gradient synergistic blending system of activated ceramic waste powder, and an interface transition layer is set between adjacent functional zones.

[0036] The high-stress zone accounts for 30% of the total length of the pole, the medium-stress zone accounts for 50% of the total length of the pole, and the low-stress zone accounts for 20% of the total length of the pole; the axial thickness of the interface transition layer is 65mm.

[0037] Among them, the concrete mix proportions for each functional area are based on 100 parts by weight. Based on silicate cement: The high-stress zone contains 100 parts cement, 27.5 parts silica fume, 17.5 parts S95 grade mineral powder, 200 parts aggregate, 1.0 part hook-shaped steel fiber, and 0.175 parts polypropylene coarse fiber, with a water-cement ratio of 0.185. The dosage of polycarboxylate superplasticizer is 1.35% of the total mass of cementitious materials. The intermediate stress zone contains 87.5 parts cement, 27.5 parts silica fume, 17.5 parts S95 grade mineral powder, 12.5 parts activated ceramic waste powder, 220 parts aggregate, 0.65 parts end-hook steel fiber, and 0.125 parts polypropylene coarse fiber, with a water-cement ratio of 0.195. The dosage of polycarboxylate superplasticizer is 1.15% of the total mass of cementitious materials. The weak stress zone contains 77.5 parts cement, 27.5 parts silica fume, 17.5 parts S95 grade mineral powder, 22.5 parts activated ceramic waste powder, 140 parts aggregate, 0.25 parts coarse polypropylene fiber, 0.125 parts fine polypropylene fiber, a water-cement ratio of 0.205, and polycarboxylate superplasticizer at a dosage of 0.95% of the total mass of cementitious materials.

[0038] The aggregate in the high-stress zone is composed of a mixture of quartz sand and basalt crushed stone with a particle size of 5-10mm at a weight ratio of 0.7:1; the aggregate in the medium-stress zone is composed of a mixture of quartz sand and basalt crushed stone with a particle size of 5-10mm at a weight ratio of 1:1; and the aggregate in the weak-stress zone is pure quartz sand.

[0039] The activated ceramic waste powder used in this embodiment was prepared in Preparation Example 1.

[0040] S2. Preparation of Reinforcing Cage and Mold: Prepare the reinforcing cage, set up a zoned high-frequency vibrator on the inner wall of the centrifugal steel mold, and spray the seed slurry obtained by carbonization treatment of centrifugal residue to form a seed interface layer.

[0041] The preparation of the steel cage includes: the prestressed main reinforcement ratio in the strong stress zone is 50% higher than that in the weak stress zone; the spacing of the spiral reinforcement in the strong stress zone is 50% denser than that in the medium stress zone and the weak stress zone; the spacing of the spiral reinforcement within 1.45m at both ends of the pole is 70mm; and the spacing of the spiral reinforcement in the middle section is 100mm.

[0042] Among them, the inner wall of the centrifugal steel mold of the combined mode is equipped with three sets of independent and controllable high-frequency vibrators along the axial direction corresponding to the three functional areas. Each set of vibrators can independently adjust the vibration frequency and amplitude. The mold ends are equipped with a frequency conversion drive mechanism that can switch between forward and reverse.

[0043] The preparation method of the seed slurry is as follows: collect the fresh residual slurry discharged after centrifugation molding, filter it through a 100-mesh sieve to remove large particle impurities, and then pass the tail gas generated during the wet heat activation of ceramic waste into the residual slurry after purification by a gas-liquid separator. Carbonate the slurry for 12.5 min at a stirring rate of 60 r / min to generate calcium carbonate crystal nuclei. Spray the obtained seed slurry onto the inner wall of the steel mold and the outer edge of the reinforcing cage to form a seed interface layer with a thickness of 0.4 mm.

[0044] Immediately after the carbonated seed slurry is sprayed, a layer of 9mm long short-cut basalt fibers is evenly spread in the interface area of ​​the corresponding interface transition layer, with a spreading amount of 0.3kg / m. 2 Short basalt fibers are embedded in the seed crystal interface layer; after the seed crystal interface layer has initially solidified, apply release agent twice.

[0045] S3. Axial stepped concrete placement: In the order from root to tip, concrete in the strong stress zone, the first interface transition concrete, the medium stress zone concrete, the second interface transition concrete, and the weak stress zone concrete are injected into the mold in sequence. After each area is placed, the corresponding high-frequency vibrator is started for pre-compaction.

[0046] The first interface transition concrete is prepared by mixing concrete from the strong stress zone and the medium stress zone in a 1:1 volume ratio. The second interface transition concrete is prepared by mixing concrete from the medium stress zone and the weak stress zone in a 1:1 volume ratio. When placing the material in each area, only the vibrator of the corresponding area is activated, while the vibrators of adjacent areas remain closed.

[0047] S4. Two-way graded centrifugal molding: A two-way centrifugal system with alternating forward and reverse rotation is adopted. Combined with the dynamic matching of the speed difference and the water-cement ratio of concrete in each functional area, as well as the coordinated vibration of each zone, the compact molding of concrete is completed.

[0048] The specific process for bidirectional graded centrifugal molding is as follows: Low-speed material feeding stage: The mold rotates in the forward direction at a speed of 200 r / min for 2.5 min, and the high-frequency vibrator is turned on throughout the entire process; Medium-speed transition phase: The mold first rotates forward at 375 r / min for 1.1 min, then rotates in reverse at a speed 10% higher than the forward speed for 1.1 min. Only the high-frequency vibrator in the high-stress zone is activated. For every 0.01 decrease in the water-to-glue ratio, the difference between the forward and reverse rotation speeds increases by 1.1%. High-speed compaction stage: The mold rotates in the forward direction, adopting a three-stage stepped speed increase. The initial speed is 400 r / min, each stage increases by 50 r / min and is maintained for 2 minutes, and the final speed is 570 r / min. The total duration is 7 minutes. Only the high-frequency vibrator in the high-stress area is turned on and the frequency increases synchronously with the speed.

[0049] S5. Staged tensioning and coordinated curing: After demolding, the prestressed main reinforcement is subjected to initial tensioning and static curing under normal pressure, secondary tensioning and constant temperature and humidity curing, release tension and residual stress control, high-pressure final curing and hydration coordinated vibration to achieve dynamic matching between prestress establishment and concrete strength growth.

[0050] The specific system for phased tensioning and coordinated maintenance is as follows: Initial tensioning and static curing at normal pressure: Apply 30% of the design tensioning control stress to the prestressed main reinforcement and temporarily lock it. Heat it to 60℃ at a uniform rate of 10℃ / h and statically cure it at normal pressure for 3 hours. Secondary tensioning and constant temperature and humidity: The tensioning is increased to 100% of the design tensioning control stress and permanently locked. The tensioning process adopts a dual control mode of stress value and elongation value. The tensioning stress deviation is no more than 1%, and the elongation value deviation is no more than ±1%. The temperature is uniformly increased to 90℃ at a rate of 15℃ / h and then kept at constant temperature and humidity for 8 hours. Tensioning and residual stress control: After demolding, apply a reverse top pressure of 22.5% of the design tension control stress to the end of the steel cage in the high-stress area of ​​the pole, hold for 30 seconds, and then unload. High-pressure final curing and hydration vibration: The pressure was uniformly increased to 1.0 MPa and 180℃ at a rate of 0.3 MPa / h, and kept constant at the same temperature and pressure for 6 hours. During this period, axial low-frequency vibration was performed once every 2 hours, with a frequency of 17.5 Hz and a single vibration duration of 1 minute.

[0051] S6. Finished product post-processing and natural curing: End caps are applied to both ends of the poles, waterproofing agent is applied to the outer surface, and the poles are sent to the storage yard for natural curing.

[0052] The post-processing and natural curing of the finished product are as follows: the inner cavity of the pole is sealed with micro-expansion cement mortar at both ends, and 1.5 coats of water-based nano-silicon waterproofing agent are evenly applied to the outer surface. The pole is then naturally cured in the storage yard for 14 days, during which time water is sprayed twice a day to keep the surface of the pole continuously moist.

[0053] Example 2: This example provides a method for preparing a high-strength concrete pole, including the following steps: S1. Gradient Formula Design: Based on the axial force distribution of the pole, the pole is divided into a strong force zone, a medium force zone, and a weak force zone along the axial direction. Differentiated concrete mix proportions are designed for each functional zone to construct a gradient synergistic blending system of activated ceramic waste powder, and an interface transition layer is set between adjacent functional zones.

[0054] The high-stress zone accounts for 25% of the total length of the pole, the medium-stress zone accounts for 45% of the total length of the pole, and the low-stress zone accounts for 15% of the total length of the pole; the axial thickness of the interface transition layer is 50mm.

[0055] Among them, the concrete mix proportions for each functional area are based on 100 parts by weight. Based on silicate cement: The high-stress zone contains 100 parts cement, 25 parts silica fume, 15 parts S95 grade mineral powder, 180 parts aggregate, 0.8 parts hook-shaped steel fiber, and 0.15 parts polypropylene coarse fiber, with a water-cement ratio of 0.18. The dosage of polycarboxylate superplasticizer is 1.2% of the total mass of cementitious materials. The intermediate stress zone contains 85 parts cement, 25 parts silica fume, 15 parts S95 grade mineral powder, 10 parts activated ceramic waste powder, 200 parts aggregate, 0.5 parts end-hook steel fiber, 0.1 parts polypropylene coarse fiber, a water-cement ratio of 0.19, and polycarboxylate superplasticizer at a dosage of 1.0% of the total mass of cementitious materials. The weak stress zone contains 75 parts cement, 25 parts silica fume, 15 parts S95 grade mineral powder, 20 parts activated ceramic waste powder, 120 parts aggregate, 0.2 parts coarse polypropylene fiber, 0.1 parts fine polypropylene fiber, a water-cement ratio of 0.20, and polycarboxylate superplasticizer at a dosage of 0.8% of the total mass of cementitious materials.

[0056] The aggregate in the high-stress zone is composed of a mixture of quartz sand and basalt crushed stone with a particle size of 5-10mm at a weight ratio of 0.6:1; the aggregate in the medium-stress zone is composed of a mixture of quartz sand and basalt crushed stone with a particle size of 5-10mm at a weight ratio of 0.9:1; and the aggregate in the weak-stress zone is all quartz sand.

[0057] The activated ceramic waste powder used in this embodiment was prepared in Preparation Example 1.

[0058] S2. Preparation of Reinforcing Cage and Mold: Prepare the reinforcing cage, set up a zoned high-frequency vibrator on the inner wall of the centrifugal steel mold, and spray the seed slurry obtained by carbonization treatment of centrifugal residue to form a seed interface layer.

[0059] The preparation of the steel cage includes: the prestressed main reinforcement ratio in the strong stress zone is 40% higher than that in the weak stress zone; the spacing of the spiral reinforcement in the strong stress zone is 45% denser than that in the medium stress zone and the weak stress zone; the spacing of the spiral reinforcement within 1.4m at both ends of the pole is 60mm; and the spacing of the spiral reinforcement in the middle section is 90mm.

[0060] Among them, the inner wall of the centrifugal steel mold of the combined mode is equipped with three sets of independent and controllable high-frequency vibrators along the axial direction corresponding to the three functional areas. Each set of vibrators can independently adjust the vibration frequency and amplitude. The mold ends are equipped with a frequency conversion drive mechanism that can switch between forward and reverse.

[0061] The method for preparing the seed slurry is as follows: collect the fresh residual slurry discharged after centrifugation molding, filter it through a 100-mesh sieve to remove large particulate impurities, and then pass the tail gas generated during the wet heat activation of ceramic waste into the residual slurry after purification by a gas-liquid separator. Carbonate the slurry for 10 minutes under a stirring rate of 60 r / min to generate calcium carbonate crystal nuclei. Spray the obtained seed slurry onto the inner wall of the steel mold and the outer edge of the reinforcing cage to form a seed interface layer with a thickness of 0.3 mm.

[0062] Immediately after the carbonated seed slurry is sprayed, a layer of 6mm long short-cut basalt fibers is evenly spread in the interface area of ​​the corresponding interface transition layer, with a spreading amount of 0.2kg / m. 2 Short basalt fibers are embedded in the seed crystal interface layer; after the seed crystal interface layer has initially solidified, apply release agent twice.

[0063] S3. Axial stepped concrete placement: In the order from root to tip, concrete in the strong stress zone, the first interface transition concrete, the medium stress zone concrete, the second interface transition concrete, and the weak stress zone concrete are injected into the mold in sequence. After each area is placed, the corresponding high-frequency vibrator is started for pre-compaction.

[0064] The first interface transition concrete is prepared by mixing concrete from the strong stress zone and the medium stress zone in a 1:1 volume ratio. The second interface transition concrete is prepared by mixing concrete from the medium stress zone and the weak stress zone in a 1:1 volume ratio. When placing the material in each area, only the vibrator of the corresponding area is activated, while the vibrators of adjacent areas remain closed.

[0065] S4. Two-way graded centrifugal molding: A two-way centrifugal system with alternating forward and reverse rotation is adopted. Combined with the dynamic matching of the speed difference and the water-cement ratio of concrete in each functional area, as well as the coordinated vibration of each zone, the compact molding of concrete is completed.

[0066] The specific process for bidirectional graded centrifugal molding is as follows: Low-speed material feeding stage: The mold rotates forward at a speed of 180 r / min for 2 minutes, and the high-frequency vibrator is turned on throughout the entire process. Medium-speed transition phase: The mold first rotates forward at 350 r / min for 1 minute, then rotates in the reverse direction at an 8% higher speed than the forward speed for 1 minute. Only the high-frequency vibrator in the high-stress zone is activated. For every 0.01 decrease in the water-to-glue ratio, the difference between the forward and reverse rotation speeds increases by 1%. High-speed compaction stage: The mold rotates in the forward direction, adopting a three-stage stepped speed increase. The initial speed is 380 r / min, each stage increases by 50 r / min and is maintained for 2 minutes, and the final speed is 520 r / min. The total duration is 6 minutes. Only the high-frequency vibrator in the high-stress area is turned on and the frequency increases synchronously with the speed.

[0067] S5. Staged tensioning and coordinated curing: After demolding, the prestressed main reinforcement is subjected to initial tensioning and static curing under normal pressure, secondary tensioning and constant temperature and humidity curing, release tension and residual stress control, high-pressure final curing and hydration coordinated vibration to achieve dynamic matching between prestress establishment and concrete strength growth.

[0068] The specific system for phased tensioning and coordinated maintenance is as follows: Initial tensioning and static curing at normal pressure: Apply 28% of the design tensioning control stress to the prestressed main reinforcement and temporarily lock it. Heat it at a constant rate of 8℃ / h to 58℃ and statically cure it at normal pressure for 2.8h. Secondary tensioning and constant temperature and humidity: The tensioning is increased to 100% of the design tensioning control stress and permanently locked. The tensioning process adopts a dual control mode of stress value and elongation value. The tensioning stress deviation is no more than 1%, and the elongation value deviation is no more than ±1%. The temperature is uniformly increased to 85℃ at a rate of 14℃ / h and then kept at constant temperature and humidity for 7 hours. Tensioning and residual stress control: After demolding, apply a reverse top pressure stress of 20% of the design tension control stress to the end of the steel cage in the strong stress zone of the pole, hold for 25 seconds and then unload; High-pressure final curing and hydration vibration: The pressure was uniformly increased to 0.8 MPa and 175℃ at a rate of 0.2 MPa / h, and kept constant at the same temperature and pressure for 5 hours. During this period, axial low-frequency vibration was performed once every 1.8 hours, with a frequency of 15 Hz and a single vibration duration of 0.8 min.

[0069] S6. Finished product post-processing and natural curing: End caps are applied to both ends of the poles, waterproofing agent is applied to the outer surface, and the poles are sent to the storage yard for natural curing.

[0070] The post-processing and natural curing of the finished product are as follows: the inner cavity of the pole is sealed with micro-expansion cement mortar at both ends, and a layer of water-based nano-silicon waterproofing agent is evenly applied to the outer surface. The pole is then naturally cured in the storage yard for 12 days, during which time water is sprayed once a day to keep the surface of the pole continuously moist.

[0071] Example 3: This example provides a method for preparing a high-strength concrete pole, including the following steps: S1. Gradient Formula Design: Based on the axial force distribution of the pole, the pole is divided into a strong force zone, a medium force zone, and a weak force zone along the axial direction. Differentiated concrete mix proportions are designed for each functional zone to construct a gradient synergistic blending system of activated ceramic waste powder, and an interface transition layer is set between adjacent functional zones.

[0072] The high-stress zone accounts for 35% of the total length of the pole, the medium-stress zone accounts for 55% of the total length of the pole, and the low-stress zone accounts for 25% of the total length of the pole; the axial thickness of the interface transition layer is 80mm.

[0073] Among them, the concrete mix proportions for each functional area are based on 100 parts by weight. Based on silicate cement: The high-stress zone contains 100 parts cement, 30 parts silica fume, 20 parts S95 grade mineral powder, 220 parts aggregate, 1.2 parts end-hook steel fiber, and 0.2 parts polypropylene coarse fiber, with a water-cement ratio of 0.19. The dosage of polycarboxylate superplasticizer is 1.5% of the total mass of cementitious materials. The intermediate stress zone contains 90 parts cement, 30 parts silica fume, 20 parts S95 grade mineral powder, 15 parts activated ceramic waste powder, 240 parts aggregate, 0.8 parts end-hook steel fiber, 0.15 parts polypropylene coarse fiber, a water-cement ratio of 0.20, and polycarboxylate superplasticizer at a dosage of 1.3% of the total mass of cementitious materials. The weak stress zone contains 80 parts cement, 30 parts silica fume, 20 parts S95 grade mineral powder, 25 parts activated ceramic waste powder, 160 parts aggregate, 0.3 parts coarse polypropylene fiber, 0.15 parts fine polypropylene fiber, a water-cement ratio of 0.21, and the dosage of polycarboxylate superplasticizer is 1.1% of the total mass of cementitious materials.

[0074] The aggregate in the high-stress zone is composed of a mixture of quartz sand and basalt crushed stone with a particle size of 5-10mm at a weight ratio of 0.8:1; the aggregate in the medium-stress zone is composed of a mixture of quartz sand and basalt crushed stone with a particle size of 5-10mm at a weight ratio of 1.1:1; and the aggregate in the weak-stress zone is all quartz sand.

[0075] The activated ceramic waste powder used in this embodiment was prepared in Preparation Example 1.

[0076] S2. Preparation of Reinforcing Cage and Mold: Prepare the reinforcing cage, set up a zoned high-frequency vibrator on the inner wall of the centrifugal steel mold, and spray the seed slurry obtained by carbonization treatment of centrifugal residue to form a seed interface layer.

[0077] The preparation of the steel cage includes: the prestressed main reinforcement ratio in the strong stress zone is 60% higher than that in the weak stress zone; the spacing of the spiral reinforcement in the strong stress zone is 55% denser than that in the medium stress zone and the weak stress zone; the spacing of the spiral reinforcement within 1.5m at both ends of the pole is 80mm; and the spacing of the spiral reinforcement in the middle section is 110mm.

[0078] Among them, the inner wall of the centrifugal steel mold of the combined mode is equipped with three sets of independent and controllable high-frequency vibrators along the axial direction corresponding to the three functional areas. Each set of vibrators can independently adjust the vibration frequency and amplitude. The mold ends are equipped with a frequency conversion drive mechanism that can switch between forward and reverse.

[0079] The method for preparing the seed slurry is as follows: collect the fresh residual slurry discharged after centrifugation molding, filter it through a 100-mesh sieve to remove large particulate impurities, and then pass the tail gas generated during the wet heat activation of ceramic waste into the residual slurry after purification by a gas-liquid separator. Carbonate the slurry for 15 minutes under a stirring rate of 60 r / min to generate calcium carbonate crystal nuclei. Spray the obtained seed slurry onto the inner wall of the steel mold and the outer edge of the reinforcing cage to form a seed interface layer with a thickness of 0.5 mm.

[0080] Immediately after the carbonated seed slurry is sprayed, a layer of 12mm long short-cut basalt fibers is evenly spread in the interface area of ​​the corresponding interface transition layer, with a spreading amount of 0.4kg / m. 2 Short basalt fibers are embedded in the seed crystal interface layer; after the seed crystal interface layer has initially solidified, apply release agent three times.

[0081] S3. Axial stepped concrete placement: In the order from root to tip, concrete in the strong stress zone, the first interface transition concrete, the medium stress zone concrete, the second interface transition concrete, and the weak stress zone concrete are injected into the mold in sequence. After each area is placed, the corresponding high-frequency vibrator is started for pre-compaction.

[0082] The first interface transition concrete is prepared by mixing concrete from the strong stress zone and the medium stress zone in a 1:1 volume ratio. The second interface transition concrete is prepared by mixing concrete from the medium stress zone and the weak stress zone in a 1:1 volume ratio. When placing the material in each area, only the vibrator of the corresponding area is activated, while the vibrators of adjacent areas remain closed.

[0083] S4. Two-way graded centrifugal molding: A two-way centrifugal system with alternating forward and reverse rotation is adopted. Combined with the dynamic matching of the speed difference and the water-cement ratio of concrete in each functional area, as well as the coordinated vibration of each zone, the compact molding of concrete is completed.

[0084] The specific process for bidirectional graded centrifugal molding is as follows: Low-speed material feeding stage: The mold rotates forward at a speed of 220 r / min for 3 minutes, and the high-frequency vibrator is turned on throughout the entire process; Medium-speed transition phase: The mold first rotates forward at 400 r / min for 1.2 min, then rotates in reverse at a speed 12% higher than the forward speed for 1.2 min. Only the high-frequency vibrator in the high-stress area is activated. For every 0.01 decrease in the water-to-glue ratio, the difference between the forward and reverse rotation speeds increases by 1.2%. High-speed compaction stage: The mold rotates in the forward direction, adopting a three-stage stepped speed increase. The initial speed is 420 r / min, each stage increases by 50 r / min and is maintained for 2 minutes, and the final speed is 620 r / min. The total duration is 8 minutes. Only the high-frequency vibrator in the high-stress area is turned on and the frequency increases synchronously with the speed.

[0085] S5. Staged tensioning and coordinated curing: After demolding, the prestressed main reinforcement is subjected to initial tensioning and static curing under normal pressure, secondary tensioning and constant temperature and humidity curing, release tension and residual stress control, high-pressure final curing and hydration coordinated vibration to achieve dynamic matching between prestress establishment and concrete strength growth.

[0086] The specific system for phased tensioning and coordinated maintenance is as follows: Initial tensioning and static curing at normal pressure: Apply 32% of the design tensioning control stress to the prestressed main reinforcement and temporarily lock it, then heat it to 62℃ at a uniform rate of 12℃ / h and statically cure it at normal pressure for 3.2h. Secondary tensioning and constant temperature and humidity: The tensioning is increased to 100% of the design tension control stress and permanently locked. The tensioning process adopts a dual control mode of stress value and elongation value. The tension stress deviation is no more than 1%, and the elongation value deviation is no more than ±1%. The temperature is uniformly increased to 95℃ at a rate of 16℃ / h and then kept at constant temperature and humidity for 9 hours. Tensioning and residual stress control: After demolding, apply a reverse top pressure stress of 25% of the design tension control stress to the end of the steel cage in the strong stress zone of the pole, hold for 35 seconds and then unload; High-pressure final curing and hydration vibration: The pressure was uniformly increased to 1.2 MPa and 185℃ at a rate of 0.4 MPa / h, and kept constant at the same temperature and pressure for 7 hours. During this period, axial low-frequency vibration was performed once every 2.2 hours, with a frequency of 20 Hz and a single vibration duration of 1.2 min.

[0087] S6. Finished product post-processing and natural curing: End caps are applied to both ends of the poles, waterproofing agent is applied to the outer surface, and the poles are sent to the storage yard for natural curing.

[0088] The post-processing and natural curing of the finished product are as follows: the inner cavity of the pole is sealed with micro-expansion cement mortar at both ends, and two coats of water-based nano-silicon waterproofing agent are evenly applied to the outer surface. The pole is then naturally cured in the storage yard for 16 days, during which time water is sprayed three times a day to keep the surface of the pole continuously moist.

[0089] Comparative Example 1: The only difference between this comparative example and Example 1 is that 12.5 parts of activated ceramic waste powder were added to the concrete mix proportions of all three functional zones. The amounts of other cementitious materials were adjusted proportionally as follows: High-stress zone: 87.5 parts cement, 27.5 parts silica fume, 17.5 parts S95 grade mineral powder, and 12.5 parts activated ceramic waste powder; Medium-stress zone: exactly the same as Example 1; Weak-stress zone: 87.5 parts cement, 27.5 parts silica fume, 17.5 parts S95 grade mineral powder, and 12.5 parts activated ceramic waste powder; All other raw materials, proportions, and process parameters were exactly the same as in Example 1.

[0090] Comparative Example 2: The only difference between this comparative example and Example 1 is that, in step S1, the concrete mix proportions for each functional area do not include activated ceramic waste powder, thus reducing the amount of cementitious materials used. The silicate cement and other materials were substituted, while the remaining components and dosages were the same as in Example 1.

[0091] Comparative Example 3: The only difference between this comparative example and Example 1 is that after the carbonated seed slurry is sprayed, short-cut basalt fibers are not sprinkled, and the release agent is applied directly after the seed interface layer has initially set; all other raw materials, proportions and process parameters are exactly the same as in Example 1.

[0092] Comparative Example 4: The only difference between this comparative example and Example 1 is that: in step S3, when laying the material in the axial steps, three sets of high-frequency vibrators are started for pre-compaction after each area is laid; all other raw materials, proportions and process parameters are exactly the same as in Example 1.

[0093] Comparative Example 5: This comparative example differs from Example 1 only in that step S5, the staged tensioning and coordinated curing, is replaced by traditional one-time tensioning and overall curing. The specific procedure is as follows: After centrifugal molding, the prestressed main tendons are subjected to 100% of the design tension control stress in one go and permanently locked. The tensioning process adopts a dual control mode of stress value and elongation value. Then, the mold is sent to an atmospheric pressure curing kiln and heated to 90°C at a uniform rate of 15°C / h, and cured at atmospheric pressure, constant temperature and humidity for 11 hours. After demolding, it is directly sent to a high-pressure steam curing kettle and pressurized to 1.0MPa and 180°C at a uniform rate of 0.3MPa / h, and kept at constant temperature and pressure for 6 hours. After natural cooling to room temperature, it is removed from the kettle. No residual stress reverse pressing treatment is performed. All other raw materials, proportions and process parameters are exactly the same as in Example 1.

[0094] Comparative Example 6: This comparative example differs from Example 1 only in that it adopts the industry-standard, fully-process preparation method for ordinary high-strength concrete poles, as follows: The entire pole uses a uniform concrete mix proportion: based on 100 parts by weight Based on silicate cement, the mixture contains 100 parts cement, 27.5 parts silica fume, 17.5 parts S95 grade mineral powder, 200 parts aggregate, 0.65 parts end-hook steel fiber, and 0.125 parts polypropylene coarse fiber, with a water-cement ratio of 0.19. The dosage of polycarboxylate superplasticizer is 1.15% of the total mass of cementitious materials. The aggregate is composed of quartz sand and basalt crushed stone with a particle size of 5-10mm mixed in a 1:1 weight ratio. The entire rod adopts uniform reinforcement: the main reinforcement ratio is 1.2%, the spiral reinforcement spacing is 100mm, and the spiral reinforcement spacing within 1.45m at both ends is 70mm. The traditional one-time integral fabric placement and unidirectional graded centrifugal molding process is adopted. The traditional one-time tensioning and integral curing process is adopted, the same as comparative example 5. The post-treatment and natural curing of the finished product are the same as in example 1.

[0095] I. Ultimate Bending Capacity Test: Referring to GB / T4623-2014 "Circular Concrete Poles", the ultimate bending capacity of the poles prepared in Examples 1-3 and Comparative Examples 1-6 were tested respectively. All specimens were 12m tapered prestressed concrete poles of the same specifications, with a tip diameter of 190mm, a root diameter of 350mm, and a wall thickness of 50mm. Three parallel specimens were prepared for each group, and the arithmetic mean was taken as the final test result. A special bending testing machine for poles was used for the test. The pole was placed horizontally on two supports with a support distance of 11.5m. The tip extended 0.5m beyond the supports. A concentrated load was applied at a distance of 1.0m from the tip using a graded loading method. Each load was 5% of the expected failure load, and each load was held for 3 minutes. The deflection value under each load was recorded. When the main reinforcement in the tension zone of the pole fractured or the concrete in the compression zone crushed, the loading was stopped, and the ultimate load value at this time was recorded. The ultimate bending capacity was then calculated.

[0096] II. Interface Shear Strength Test: Referring to GB / T50152-2012 "Standard for Test Methods of Concrete Structures", the interface shear strength of the poles prepared in Examples 1-3 and Comparative Examples 1-6 was tested respectively. Cylindrical core samples with a diameter of 100 mm and a height of 200 mm were drilled from the interface transition layer between the strong and medium stress zones, and between the medium and weak stress zones of each pole group. Three core samples were drilled from each interface, for a total of six core samples per pole group. The arithmetic mean was taken as the final test result. A universal testing machine was used, employing the direct shear test method. The core sample was horizontally fixed in a shear fixture, with the shear surface coinciding with the interface transition layer. A uniform horizontal shear load of 0.5 MPa / s was applied until shear failure occurred along the interface. The maximum shear load at failure was recorded, and the interface shear strength was calculated.

[0097] III. Cracking Load and Crack Resistance Grade Test: Referring to GB / T4623-2014 "Circular Concrete Poles", the cracking load and crack resistance grade of the poles prepared in Examples 1-3 and Comparative Examples 1-6 were tested respectively. All samples used poles of the same specifications as those used in the ultimate bending capacity test. Three parallel samples were prepared for each group, and the arithmetic mean was taken as the final test result. The test used the same loading device and graded loading method as the ultimate bending capacity test. Each load was held for 3 minutes. The surface of the tension zone of the pole was observed with a 20x magnifying glass. When the first crack with a width greater than 0.05 mm appeared, the load value at this time was recorded as the cracking load. The cracking moment was calculated, and the crack resistance grade of the pole was determined according to the ratio of the cracking moment to the standard moment.

[0098] IV. 28-day chloride ion permeability coefficient test: Referring to GB / T50082-2009 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete", the 28-day chloride ion permeability coefficient of the poles prepared in Examples 1-3 and Comparative Examples 1-6 was tested respectively. Cylindrical core samples with a diameter of 100 mm and a height of 50 mm were drilled from the strong stress zone, medium stress zone, and weak stress zone of each pole group. Three core samples were drilled from each zone, for a total of nine core samples per pole group. The arithmetic mean was taken as the final test result. The test used the electrical flux method. The core samples were soaked in water at 20℃ for 48 hours until saturated, installed in the test tank of the RCM chloride ion diffusion coefficient measuring instrument, and a 60V DC voltage was applied between a 0.3mol / L NaOH solution and a 3% NaCl solution for 6 hours. The electrical flux through the core sample was measured, and the 28-day chloride ion permeability coefficient was calculated.

[0099] Table 1: Test Results of Ultimate Bending Capacity

[0100] Table 2: Results of Interface Shear Strength Test

[0101] Table 3: Test Results of Cracking Load and Cracking Resistance Grade

[0102] Table 4: Chloride ion permeability coefficient test results after 28 days

[0103] Based on Examples 1-3 and Comparative Example 1, and in conjunction with Tables 1 and 4, it can be seen that there are significant performance differences between the gradient addition method of activated ceramic waste powder and the uniform addition method throughout the pole. Gradient addition can accurately match the material properties according to the stress requirements of different areas of the pole, avoiding the problems of insufficient strength in strong stress areas and material waste in weak stress areas. At the same time, it forms a durability gradient that adapts to the stress distribution. In contrast, uniform addition will destroy this performance matching relationship, resulting in a decrease in the overall mechanical properties and material utilization rate of the pole.

[0104] Based on Examples 1-3 and Comparative Example 2, and in conjunction with Tables 1 and 4, it can be seen that activated ceramic waste powder has a significant impact on the strength and durability of concrete. It can not only replace part of the cement to reduce production costs, but also generate hydration products through pozzolanic reaction, effectively refining the internal pore structure of concrete and improving its density and impermeability. Without the addition of activated ceramic waste powder, the durability of concrete will decrease significantly, and its mechanical properties will also be affected to some extent.

[0105] As can be seen from Examples 1-3 and Comparative Example 3, and Tables 1-3, chopped basalt fibers and carbonated seed slurry have a significant synergistic reinforcing effect. Chopped basalt fibers can form a physical bridging structure at the interface, which, combined with the chemically induced hydration of the seed slurry, significantly improves the interfacial bonding strength between different functional zones. At the same time, it can also prevent the axial movement of aggregates during centrifugation. Without the application of chopped basalt fibers, the interface will become a weak point in the pole, thereby affecting the overall mechanical properties and crack resistance of the pole.

[0106] As can be seen from Examples 1-3 and Comparative Example 4, and Tables 1-4, zoned independent vibration control is a key process to ensure the successful implementation of gradient formulation. When placing concrete, only the vibrator in the corresponding area can effectively prevent vibration energy from being transmitted along the axial direction, prevent concrete of different formulations from mixing, and maintain the performance differences of each functional area. However, full-section vibration will lead to serious material mixing problems, destroy the performance distribution of gradient formulation, and significantly reduce the overall performance of the pole.

[0107] Based on Examples 1-3 and Comparative Example 5, and in conjunction with Tables 1 and 3, it can be seen that the staged tensioning and coordinated curing process can achieve dynamic matching between prestress establishment and concrete strength growth, effectively reducing prestress loss caused by concrete shrinkage and creep. At the same time, the residual stress reverse pressure eliminates stress concentration in the high-stress area. The traditional one-time tensioning and overall curing process results in greater prestress loss, insufficient crack resistance safety reserve of the pole, and is more prone to cracking during long-term service.

[0108] As can be seen from Examples 1-3 and Comparative Example 6, and Tables 1-4, the overall technical solution proposed in this application has comprehensive performance advantages compared with the common pole manufacturing methods used in the industry. Through the synergistic effect of a series of technical means such as gradient formula design, dual interface strengthening, zoned anti-channeling material molding, and staged tensioning and curing, the ultimate bending bearing capacity, interface bonding strength, crack resistance and long-term durability of the pole can be significantly improved. At the same time, it realizes the high-value utilization of industrial solid waste, and has good technical, economic and environmental benefits.

[0109] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a high-strength concrete pole, characterized in that: Includes the following steps: S1. Gradient Formula Design: Based on the axial force distribution of the pole, the pole is divided into a strong force zone, a medium force zone and a weak force zone along the axial direction. Differentiated concrete mix proportions are designed for each functional zone to construct a gradient synergistic blending system of activated ceramic waste powder, and an interface transition layer is set between adjacent functional zones. S2. Preparation of steel cage and mold: Prepare steel cage, set up a partitioned high-frequency vibrator on the inner wall of the centrifugal steel mold, and spray the carbonized seed slurry obtained by carbonation treatment of centrifugal residue to form a seed interface layer. S3, Axial stepped concrete placement: In the order from root to tip, concrete in the strong stress zone, the first interface transition concrete, the medium stress zone, the second interface transition concrete and the weak stress zone are injected into the mold in sequence. After each area is placed, the corresponding high-frequency vibrator is started for pre-compaction. S4. Two-way graded centrifugal molding: A two-way centrifugal system with alternating forward and reverse rotation is adopted. Combined with the dynamic matching of the speed difference and the water-cement ratio of concrete in each functional area, as well as the coordinated vibration of each zone, the compact molding of concrete is completed. S5. Staged tensioning and coordinated curing: After demolding, the prestressed main reinforcement is subjected to initial tensioning and normal pressure static curing, secondary tensioning and constant temperature and humidity curing, release tension and residual stress control, high pressure final curing and hydration coordinated vibration to complete the dynamic matching of prestress establishment and concrete strength growth. S6. Finished product post-processing and natural curing: End caps are applied to both ends of the poles, waterproofing agent is applied to the outer surface, and the poles are sent to the storage yard for natural curing.

2. The method for preparing a high-strength concrete pole according to claim 1, characterized in that: In step S1, the strong stress zone accounts for 25-35% of the total length of the rod, the medium stress zone accounts for 45-55% of the total length of the rod, and the weak stress zone accounts for 15-25% of the total length of the rod; the axial thickness of the interface transition layer is 50-80mm.

3. The method for preparing a high-strength concrete pole according to claim 1, characterized in that: In step S1, the concrete mix proportions for each functional area are based on 100 parts by mass. Based on silicate cement: The high-stress zone comprises 100 parts cement, 25-30 parts silica fume, 15-20 parts S95 grade mineral powder, 180-220 parts aggregate, 0.8-1.2 parts hook-shaped steel fiber, 0.15-0.2 parts polypropylene coarse fiber, a water-cement ratio of 0.18-0.19, and a polycarboxylate superplasticizer dosage of 1.2-1.5% of the total mass of the cementitious materials. The intermediate stress zone comprises 85-90 parts cement, 25-30 parts silica fume, 15-20 parts S95 grade mineral powder, 10-15 parts activated ceramic waste powder, 200-240 parts aggregate, 0.5-0.8 parts end-hook steel fiber, 0.1-0.15 parts polypropylene coarse fiber, a water-cement ratio of 0.19-0.20, and a polycarboxylate superplasticizer dosage of 1.0-1.3% of the total mass of the cementitious materials. The weak stress zone comprises 75-80 parts cement, 25-30 parts silica fume, 15-20 parts S95 grade mineral powder, 20-25 parts activated ceramic waste powder, 120-160 parts aggregate, 0.2-0.3 parts coarse polypropylene fiber, 0.1-0.15 parts fine polypropylene fiber, a water-cement ratio of 0.20-0.21, and a polycarboxylate superplasticizer dosage of 0.8-1.1% of the total mass of the cementitious materials.

4. The method for preparing a high-strength concrete pole according to claim 3, characterized in that: The aggregate in the high-stress zone is composed of a mixture of quartz sand and basalt crushed stone with a particle size of 5-10mm at a weight ratio of 0.6-0.8:1; the aggregate in the medium-stress zone is composed of a mixture of quartz sand and basalt crushed stone with a particle size of 5-10mm at a weight ratio of 0.9-1.1:1; and the aggregate in the weak-stress zone is pure quartz sand.

5. The method for preparing a high-strength concrete pole according to claim 1, characterized in that: In step S2, the preparation of the steel cage includes: the prestressed main reinforcement ratio in the strong stress zone is 40-60% higher than that in the weak stress zone; the spacing of the spiral reinforcement in the strong stress zone is 45-55% denser than that in the medium stress zone and the weak stress zone; the spacing of the spiral reinforcement within 1.4-1.5m at both ends of the pole is 60-80mm; and the spacing of the spiral reinforcement in the middle section is 90-110mm.

6. The method for preparing a high-strength concrete pole according to claim 1, characterized in that: In step S2, the preparation method of the carbonated seed slurry is as follows: collect the residual slurry discharged after centrifugal molding, introduce the tail gas generated during the wet heat activation process of ceramic waste into the residual slurry for carbonation treatment for 10-15 minutes to generate calcium carbonate crystal nuclei; spray the obtained seed slurry onto the inner wall of the steel mold and the outer edge of the reinforcing cage to form a seed interface layer with a thickness of 0.3-0.5 mm.

7. The method for preparing a high-strength concrete pole according to claim 1, characterized in that: In step S2, immediately after the carbonated seed slurry is sprayed, a layer of short-cut basalt fibers with a length of 6-12 mm is evenly spread in the interface region corresponding to the interface transition layer described in step S1, with a spreading amount of 0.2-0.4 kg / m². 2 The short-cut basalt fibers are partially embedded in the seed crystal interface layer; Apply the release agent after the seed crystal interface layer has initially solidified.

8. The method for preparing a high-strength concrete pole according to claim 1, characterized in that: In step S4, the specific process of the bidirectional graded centrifugal molding is as follows: Low-speed material feeding stage: The mold rotates forward at a speed of 180-220 r / min for 2-3 minutes, and the high-frequency vibrator is turned on throughout the entire process. Medium-speed transition stage: The mold first rotates forward at 350-400 r / min for 1-1.2 min, then rotates in reverse at a speed 8-12% higher than the forward speed for 1-1.2 min. Only the high-frequency vibrator in the high-stress area is activated. For every 0.01 decrease in the water-to-glue ratio, the difference between the forward and reverse rotation speeds increases by 1-1.2%. High-speed compaction stage: The mold rotates in the forward direction, adopting a three-stage stepped speed increase. The initial speed is 380-420 r / min, each stage increases by 50 r / min and is maintained for 2 minutes, and the final speed is 520-620 r / min. The total duration is 6-8 minutes. Only the high-frequency vibrator in the high-stress area is turned on and the frequency increases synchronously with the speed.

9. The method for preparing a high-strength concrete pole according to claim 1, characterized in that: In step S5, the specific system for staged tensioning and coordinated curing is as follows: Initial tensioning and static curing at normal pressure: Apply 28-32% of the design tensioning control stress to the prestressed main reinforcement and temporarily lock it. Heat it at a constant rate of 8-12℃ / h to 58-62℃ and statically cure it at normal pressure for 2.8-3.2h. Secondary tensioning and constant temperature and humidity: The tensioning is increased to 100% of the design tension control stress and permanently locked. The tensioning process adopts a dual control mode of stress value and elongation value. The tension stress deviation is no more than 1%, and the elongation value deviation is no more than ±1%. The temperature is uniformly increased to 85-95℃ at a rate of 14-16℃ / h and then kept at constant temperature and humidity for 7-9 hours. Tensioning and residual stress control: After demolding, apply a reverse top pressure of 20-25% of the design tension control stress to the end of the steel cage in the high-stress area of ​​the pole, hold for 25-35 seconds, and then unload. High-pressure final curing and hydration vibration: The pressure is increased uniformly to 0.8-1.2MPa and 175-185℃ at a rate of 0.2-0.4MPa / h, and the temperature and pressure are kept constant for 5-7h. During this period, axial low-frequency vibration is performed once every 1.8-2.2h, with a frequency of 15-20Hz and a single vibration duration of 0.8-1.2min.

10. The method for preparing a high-strength concrete pole according to claim 1, characterized in that: In step S6, the post-processing and natural curing of the finished product are specifically as follows: the inner cavity of the pole is sealed with micro-expansion cement mortar at both ends, and 1-2 coats of water-based nano-silicon waterproofing agent are evenly applied to the outer surface. The pole is then naturally cured in the storage yard for 12-16 days, during which time water is sprayed 1-3 times a day to keep the surface of the pole continuously moist.

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