High-friction low-thermal-conductivity prestressed concrete pipe pile processing device and method thereof

Abstract

This invention discloses a high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device, belonging to the field of concrete pipe pile processing technology. The device includes a mold, a drive unit, and a connecting shaft. It also includes a mixing mechanism comprising a mixing paddle and a telescopic mechanism. The telescopic mechanism drives the mixing paddle to move radially along the mold, and the mixing paddle mixes the concrete raw materials inside the reinforcing cage. A moisture content meter detects the real-time moisture content of the concrete raw materials. When the real-time moisture content is less than a threshold value, the controller controls the telescopic mechanism to contract, so that the distance from the sidewall of the mixing paddle to the axis of the connecting shaft is equal to the designed inner diameter of the pre-processed pipe pile, and the length direction of the mixing paddle is parallel to the axial direction of the mold. This high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device can suppress the segregation of fly ash hollow microspheres, avoid powder shedding from the inner wall, and increase the friction of the processed pipe pile.

Description

Technical Field

[0001] This invention relates to the field of concrete pipe pile processing technology, specifically to a high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device and method. Background Technology

[0002] In the field of contemporary construction engineering, prestressed concrete pipe piles are widely used in key areas such as high-rise building foundations, bridge foundations, and underground utility tunnel support due to their advantages such as high load-bearing capacity, high construction efficiency, and good economic performance. As engineering construction develops towards "deep, large, and complex" directions, and with the deepening of concepts such as "green energy saving" and "long service life," traditional prestressed concrete pipe piles are gradually revealing their performance shortcomings, making the demand for new types of pipe piles with both high friction and low thermal conductivity increasingly urgent.

[0003] High-friction, low-thermal-conductivity prestressed concrete pipe piles are typically made from concrete raw materials containing functional aggregates (such as fly ash hollow microspheres) and processed using centrifugal molding equipment. Existing centrifugal molding equipment includes a drive unit and a molding die. During the molding process of concrete pipe piles, the reinforcing cage of the concrete pipe pile is installed in the molding die, and then the concrete raw materials are poured in. The drive unit drives the molding die to rotate at high speed, thereby centrifugally molding the concrete pipe pile.

[0004] However, during the centrifugation process of concrete raw materials using traditional molding and processing equipment, the density of fly ash hollow microspheres is much lower than that of the concrete matrix (approximately 0.4-0.6 g / cm³ vs 2.4 g / cm³). As a result, the centrifugal force experienced by fly ash hollow microspheres during the centrifugation stage is relatively small, making them prone to segregation on the inner wall of the molded concrete pipe pile, forming a "fly ash hollow microsphere enrichment layer". This disrupts the uniformity of material composition and the continuity of mechanical properties in the thickness direction of the concrete pipe pile wall. Consequently, after demolding, the inner wall surface of the pipe pile is prone to powdering, slag shedding, or even peeling, leading to a reduction in the friction of the concrete pipe pile. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems in the prior art and provide a high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device, which can avoid powdering of the inner wall of the concrete pipe pile after demolding and increase the friction of the pipe pile after processing.

[0006] This invention provides a high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device, including a mold, a driving device, and a connecting shaft. The driving device is used to drive the mold to rotate around its own axis. The connecting shaft is coaxially arranged with the mold. The device also includes:

[0007] The mixing mechanism includes a mixing paddle and a telescopic mechanism. The telescopic mechanism is mounted on a connecting shaft, and the mixing paddle is connected to the telescopic mechanism. The telescopic mechanism is used to drive the mixing paddle to move radially along the mold, and the mixing paddle is used to mix the concrete raw materials inside the steel cage.

[0008] A moisture content meter is installed inside the mold. The moisture content meter is used to detect the real-time moisture content of concrete raw materials.

[0009] The controller is electrically connected to the telescopic mechanism and the moisture content detector. The controller has a preset moisture content threshold. The controller controls the telescopic mechanism to move according to the real-time moisture content of the concrete raw materials and the moisture content threshold. When the real-time moisture content is less than the moisture content threshold, the controller controls the telescopic mechanism to contract so that the distance between the side wall of the mixing paddle and the axis of the connecting shaft is equal to the design inner diameter of the pre-processed pipe pile, and the length direction of the mixing paddle is parallel to the axis of the mold.

[0010] Preferably, the telescopic mechanism includes a base and a first piston. The base is fixedly connected to the connecting shaft. The base has a sliding cavity, which is connected to a hydraulic control circuit. The hydraulic control circuit is electrically connected to a controller. The first piston is slidably connected to the sliding cavity along the radial direction of the mold. The stirring paddle is fixedly connected to the first piston. The inner wall of the sliding cavity has a first cam groove, and the side wall of the first piston has a first slider. The first slider is slidably connected to the first cam groove. When the hydraulic control circuit fills the sliding cavity with hydraulic oil, the first piston moves away from the mold axis. Under the action of the first cam groove and the first slider, the stirring paddle rotates radially around the mold.

[0011] Preferably, the mold is rotatably connected to the bracket, the bracket is provided with a sliding hole along the mold axis, the side wall of the connecting shaft is slidably connected to the sliding hole, the driving device is connected to a reciprocating mechanism, the reciprocating mechanism is connected to the connecting shaft, when the driving device drives the mold to rotate, the driving device drives the connecting shaft to move along the mold axis through the reciprocating mechanism.

[0012] Preferably, the hydraulic control circuit includes a hydraulic cylinder, a second piston, and a reversing valve. The hydraulic cylinder is fixedly connected to the bracket, the second piston is fixedly connected to the connecting shaft, and the second piston is slidably connected to the inner cavity of the hydraulic cylinder along the axial direction of the mold. Hydraulic oil is provided in the inner cavity of the hydraulic cylinder. The inner cavity of the hydraulic cylinder is connected to the oil inlet of the reversing valve. One oil outlet of the reversing valve is connected to the slide cavity, and the other oil outlet of the reversing valve is connected to the inner cavity of the hydraulic cylinder. The reversing valve is electrically connected to the controller.

[0013] Preferably, the reversing valve is an electromagnetic reversing valve. When the real-time moisture content of the concrete raw material is greater than the moisture content threshold, the controller controls the reversing valve to move so that the inner cavity of the oil cylinder is connected to the slide cavity through the reversing valve. When the real-time moisture content of the concrete raw material is less than the moisture content threshold and the connecting shaft moves to a position away from the oil cylinder, so that the hydraulic oil flows back from the slide cavity to the inner cavity of the oil cylinder, and the stirring paddle retracts to a position close to the mold shaft, the controller controls the reversing valve to switch to a position where the inner cavity of the oil cylinder is connected to the inner cavity of the oil cylinder through the reversing valve.

[0014] Preferably, the base is provided with a slot, the length direction of which is parallel to the length direction of the mold. The slot is used to lock the stirring paddle after the first piston retracts into the sliding cavity.

[0015] Preferably, the sliding hole is provided with a limiting groove along the mold axis, and a limiting slider is slidably connected in the limiting groove. The limiting groove and the limiting slider are used to prevent the connecting shaft from rotating around the mold axis.

[0016] Preferably, the reciprocating mechanism includes a cam and a drive plate. The cam is connected to the drive device, and a second cam groove is provided on the upper side wall of the cam. The drive plate is fixedly connected to the connecting shaft, and a second slider is provided at the bottom end of the drive plate. The second slider is slidably connected in the second cam groove. When the drive device drives the cam to rotate, the drive plate moves along the axial direction of the mold under the drive of the second cam groove and the second slider.

[0017] Preferably, the impeller is made of a material with a hardness of 500 HB to 800 HB.

[0018] This invention also provides a method for processing pipe piles using a high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device, comprising the following steps:

[0019] According to the mixing ratio, the cementitious materials, aggregates, and hollow microspheres are first dry-mixed for 2-3 minutes, and then water and admixtures are added and wet-mixed for 3-5 minutes to ensure that the hollow microspheres are evenly dispersed, thereby forming concrete raw materials;

[0020] After installing the reinforcing cage inside the mold, calibrate the coaxiality between the connecting shaft and the mold.

[0021] Debug the mixing mechanism to ensure that when the telescopic mechanism extends, the mixing blade covers 1 / 2 to 2 / 3 of the radial range inside the steel cage, and when it retracts, the distance between the side wall of the mixing blade and the axis is equal to the inner diameter of the pipe pile.

[0022] Calibrate the moisture content meter and set the moisture content threshold of 15%-17% in the controller;

[0023] The material is placed inside the mold, and then centrifuged gradually at a speed of "low-medium-high".

[0024] When the real-time moisture content of the concrete raw material is greater than or equal to the moisture content threshold, the controller commands the telescopic mechanism to extend, and the mixing paddle stirs the concrete raw material on the inner wall of the pipe pile as the mold rotates; when the real-time moisture content of the concrete raw material is less than the moisture content threshold, the controller commands the mixing paddle to retract, so that the mixing paddle fits against the inner wall of the pipe pile and scrapes the inner wall of the pipe pile as the mold rotates.

[0025] After demolding, the concrete is first steam-cured and then naturally cured to ensure its compressive strength and thermal conductivity.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: In the initial stage of centrifugation, the concrete raw material has a high water content. Due to its low density, the fly ash hollow microspheres easily float to the inside of the reinforcing cage with the water, forming a "hollow microsphere enrichment layer". At this time, the controller controls the telescopic mechanism to move, driving the stirring paddle to extend outward along the mold radially. As the mold rotates, the stirring paddle stirs the concrete raw material inside the reinforcing cage at a low speed, thereby breaking the upward trend of "water-hollow microspheres" and causing the hollow microspheres to redisperse into the concrete matrix. In the middle and later stages of centrifugation, the concrete discharges excess water under the action of centrifugal force, and the water content gradually drops below the water content threshold. At this time, the hollow microspheres have been stably dispersed and no further stirring is needed. The controller controls the telescopic mechanism to move in the opposite direction, thereby driving the stirring paddle to retract inward along the mold radially until the distance between the side wall of the stirring paddle and the axis of the connecting shaft is equal to the design inner diameter of the pre-processed pipe pile and the length direction of the stirring paddle is parallel to the mold axis. At this time, as the mold rotates at high speed, the stirring paddle scrapes the inner wall of the pipe pile circumferentially. By switching between stirring and leveling according to the moisture content of the concrete raw materials in the mold, the segregation of fly ash hollow microspheres in the concrete raw materials can be suppressed, preventing powdering of the inner wall of the concrete pipe pile after demolding and increasing the friction resistance of the pipe pile after processing. Furthermore, the uniform dispersion of fly ash hollow microspheres ensures low thermal conductivity of the pipe pile, while the leveling process improves the density of the inner wall, meeting the dual design requirements of "high friction resistance + low thermal conductivity".

[0027] When the first piston extends radially under hydraulic pressure, the first slider is constrained by the trajectory of the first cam groove, causing the mixing paddle to "extend radially and rotate radially." This increases the mixing range of the mixing paddle, enabling two-dimensional mixing of the concrete and improving its mixing effect. This effectively breaks the tendency of fly ash hollow microspheres to float with moisture due to their low density, preventing them from accumulating and segregating on the inner wall of the pipe pile. From the perspective of the motion mechanism, this ensures the anti-segregation effect of the entire device. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the main structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the internal first working state of the present invention;

[0030] Figure 3 This is a schematic diagram of the AA surface of the present invention;

[0031] Figure 4 This is a schematic diagram of the internal second working state of the present invention;

[0032] Figure 5 This is a schematic diagram of the first working state of the telescopic mechanism of the present invention;

[0033] Figure 6 This is a schematic diagram of the first working state of the telescopic mechanism of the present invention;

[0034] Figure 7 This is a schematic diagram of the structure of the pipe pile formed by the present invention.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1. Rebar cage; 101. Mold; 102. Drive device; 103. Connecting shaft; 104. Agitator; 105. Telescopic mechanism; 106. Moisture content meter; 201. Base; 202. First piston; 203. Slide cavity; 204. First cam groove; 205. First slider; 3. Support; 401. Hydraulic cylinder; 402. Second piston; 403. Reversing valve; 5. Slot; 601. Limiting slide groove; 602. Limiting slider; 701. Cam; 702. Drive plate; 703. Second cam groove; 704. Second slider. Detailed Implementation

[0037] The following is in conjunction with the appendix Figures 1-7 The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0038] like Figures 1-7As shown, the present invention provides a high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device, including a mold 101, a drive device 102, and a connecting shaft 103. A reinforcing cage 1 is installed inside the mold 101. The drive device 102 drives the mold 101 to rotate around its own axial direction. The connecting shaft 103 passes through the mold 101 and is coaxially arranged with the mold 101. The device also includes a mixing mechanism, a moisture content meter 106, and a controller. The mixing mechanism includes a mixing paddle 104 and a telescopic mechanism 105. The telescopic mechanism 105 is mounted on the connecting shaft 103, and the mixing paddle 104 is connected to the telescopic mechanism 105. The telescopic mechanism 105 drives the mixing paddle 104 to move radially along the mold 101. 04 is used to mix the concrete raw materials inside the reinforcing cage 1; the moisture content detector 106 is installed inside the mold 101, and the moisture content detector 106 is used to detect the real-time moisture content of the concrete raw materials; the controller is electrically connected to the telescopic mechanism 105 and the moisture content detector 106, and the controller has a preset moisture content threshold. The controller controls the telescopic mechanism 105 to move according to the real-time moisture content of the concrete raw materials and the moisture content threshold. When the real-time moisture content is less than the moisture content threshold, the controller controls the telescopic mechanism 105 to contract so that the distance between the side wall of the mixing paddle 104 and the axis of the connecting shaft 103 is equal to the design inner diameter of the pre-processed pipe pile, and the length direction of the mixing paddle 104 is parallel to the axis of the mold 101.

[0039] The working principle of the above embodiments is briefly described below:

[0040] I. Raw material preparation and equipment commissioning

[0041] 1. Concrete raw material preparation containing fly ash hollow microspheres

[0042] The mixing ratio is designed based on the performance requirements of "high friction resistance + low thermal conductivity". The core components and their proportions (by weight) are as follows:

[0043] Cementitious materials: 300-350 parts of P.O42.5 cement, 80-120 parts of Grade I fly ash (to replace part of the cement and reduce the thermal conductivity);

[0044] Functional aggregates: 50-80 parts of hollow fly ash microspheres (particle size 50-150μm, select products with high roundness and strength ≥5MPa to ensure low thermal conductivity and avoid breakage), 1100-1300 parts of continuously graded crushed stone (5-25mm), and 600-700 parts of medium sand.

[0045] Additives: 3-5 parts of polycarboxylate superplasticizer (20% solid content) (to improve fluidity and reduce water consumption to lower the risk of segregation), and 0.1-0.2 parts of air-entraining agent (to improve freeze resistance without affecting density).

[0046] Mixing water: Add as needed, and control the initial slump to 120-160mm (corresponding to an initial moisture content of about 18%-22%, which can be adjusted according to the moisture content of the aggregate).

[0047] Key control: During mixing, adopt the "dry mixing first, then wet mixing" process. First, dry mix cement, fly ash, crushed stone, sand, and fly ash hollow microspheres for 2-3 minutes to ensure that the hollow microspheres are evenly dispersed; then add mixing water and admixtures and wet mix for 3-5 minutes to prevent the hollow microspheres from floating and segregating due to excessive local moisture.

[0048] 2. Processing equipment debugging

[0049] Installation of mold 101 and steel cage 1: The pre-fabricated prestressed steel cage 1 (made according to the design reinforcement ratio of the pipe pile) is coaxially hoisted into the mold 101 to ensure that the distance between the steel cage 1 and the inner wall of the mold 101 is uniform (equal to the wall thickness of the pipe pile), and the two ends of the steel cage 1 are fixed to prevent displacement during centrifugation.

[0050] The connecting shaft 103 passes coaxially through the mold 101 to ensure that the deviation from the axis of the mold 101 is ≤0.5mm, so as to avoid the mold 101 shaking during centrifugation;

[0051] Connect the agitator 104 to the telescopic mechanism 105 (such as an electric push rod telescopic assembly or a hydraulic telescopic assembly). The telescopic mechanism 105 is fixed on the connecting shaft 103. Adjust the telescopic stroke to ensure that when the telescopic mechanism 105 is fully extended, the agitator 104 can cover 1 / 2 to 2 / 3 of the radial range inside the reinforcing cage 1; when fully retracted, the distance between the side wall of the agitator 104 and the axis of the connecting shaft 103 is equal to the inner diameter of the pre-processed pipe pile, and the length direction of the agitator 104 is parallel to the axis of the mold 101 (at this time, the agitator 104 can be used as a "scraper").

[0052] Two to three moisture content detectors 106 are evenly arranged along the axial direction on the inner wall of the mold 101 (the probe is inserted into the concrete raw material to a depth of 10-15mm), and the detection accuracy is calibrated (error ≤0.5%) to ensure real-time acquisition of concrete raw material moisture content data;

[0053] Based on the mix proportion of concrete raw materials, the moisture content threshold is determined through preliminary tests (usually 15%-17%, corresponding to a slump of 80-100mm, at which point the concrete raw materials are in a "thick plastic state", and the risk of segregation is significantly reduced), and the moisture content threshold is entered into the controller; at the same time, an electrical signal linkage is established between the controller and the telescopic mechanism 105 and the moisture content detector 106 to ensure that the response delay is ≤0.5s.

[0054] II. Fabric processing and centrifugal processing (including dynamic stirring / scraping control)

[0055] The drive device 102 drives the mold 101 to rotate at a low speed (50-80 r / min to avoid concrete material accumulation). The prepared fly ash hollow microsphere concrete is uniformly injected into the mold 101 through the material distribution port at the top of the mold 101. The material distribution amount is calculated according to the design volume of the pipe pile (including wall thickness and inner diameter) to ensure uniform material distribution (concrete material deviation ≤ 5 kg per meter along the axial direction). After the material distribution is completed, the material distribution port is closed.

[0056] The drive unit 102 controls the rotation speed of the mold 101 according to the centrifugal curve of "low-speed fabric spreading → medium-speed compaction → high-speed molding" (total centrifugation time 20-30 min). The controller receives data from the moisture content detector 106 in real time and dynamically adjusts the action of the telescopic mechanism 105, which is divided into two key stages:

[0057] Phase 1: High Moisture Content Period (Real-time Moisture Content ≥ Moisture Content Threshold) – Stirring to Prevent Segregation

[0058] In the initial stage of centrifugation (0-8 min, rotation speed 80-150 r / min), the concrete raw materials have a high water content (≥17%) and are in a "fluid plastic state". Due to their low density (approximately 0.4-0.6 g / cm³), the fly ash hollow microspheres are easily carried by the water to the inner side of the reinforcing cage 1 (the inner wall of the pipe pile to be formed), forming a "hollow microsphere enrichment layer". If no intervention is provided, it will lead to subsequent segregation and powdering.

[0059] When the moisture content meter 106 reports "real-time moisture content ≥ moisture content threshold", the controller sends an "extension command" to the telescopic mechanism 105. The telescopic mechanism 105 drives the mixing paddle 104 to extend radially outward along the mold 101 (the extension distance is adjusted according to the inner diameter of the pipe pile, usually 1 / 3-1 / 2 of the inner diameter of the pipe pile). As the mold 101 rotates (speed 150-200 r / min), the mixing paddle 104 performs low-speed mixing of the concrete material inside the reinforcing cage 1 (the linear speed of the mixing paddle 104 is 1-1.5 m / s to avoid damaging the overall compactness of the concrete material).

[0060] The mixing paddle 104 can break the upward trend of "moisture-hollow microspheres", allowing the hollow microspheres to redisperse into the concrete matrix. At the same time, the centrifugal force pushes the concrete to adhere to the inner wall of the mold 101, initially forming a dense structure of the pipe pile wall, thus preventing segregation of the inner wall from the source.

[0061] Phase 2: Low Moisture Content Period (Real-time Moisture Content < Moisture Content Threshold) – Leveling and Maintaining Friction Resistance

[0062] During the middle to late stages of centrifugation (8-30 min, rotation speed 200-300 r / min), the concrete discharges excess water under centrifugal force, and the water content gradually drops below the water content threshold (<17%). The concrete raw materials are transformed into a "thick plastic to semi-solid state". At this time, the hollow microspheres have been stably dispersed and no further stirring is required. If there is unevenness on the inner wall (such as local protrusions or pitting), it will cause powdering after demolding, reducing the frictional resistance between the pipe pile and the soil.

[0063] When the moisture content meter 106 reports "real-time moisture content ≤ moisture content threshold", the controller sends a "contraction command" to the telescopic mechanism 105. The telescopic mechanism 105 drives the agitator 104 to retract radially inward along the mold 101 until two conditions are met: (1) the distance between the side wall of the agitator 104 and the axis of the connecting shaft 103 is equal to the inner diameter of the pre-processed pipe pile; (2) the length direction of the agitator 104 is parallel to the axial direction of the mold 101. At this time, the smooth side wall of the agitator 104 becomes an "inner wall scraper". As the mold 101 rotates at high speed (speed 250-300r / min), the agitator 104 performs circumferential scraping of the inner wall of the pipe pile.

[0064] The leveling component has a fit of ≥98% with the inner wall of the pipe pile, which can remove protrusions and fill tiny depressions on the inner wall, making the surface flatness error of the inner wall ≤2mm / m; at the same time, the leveling process can further compact the inner wall concrete, improve the density (porosity ≤8%), prevent hollow microspheres from being exposed on the surface, completely solve the powdering problem, and ensure the high friction performance of the pipe pile (characteristic value of pile side friction ≥60kPa).

[0065] III. Demolding and Curing

[0066] After centrifugal molding is completed, stop the rotation of mold 101 and wait for the temperature of mold 101 to drop below 50℃ (to avoid cracking due to temperature difference). Remove the end plate of mold 101 and slowly remove the pipe pile through the demolding device.

[0067] Maintenance: A combination of steam curing and natural curing methods is used.

[0068] The pipe piles were moved into the curing kiln and cured according to the following procedure: "static stop for 2 hours (temperature 20℃-30℃) → heating up for 2 hours (heating rate ≤20℃ / h, to 60-65℃) → constant temperature for 6 hours (humidity ≥90%) → cooling down for 2 hours (cooling rate ≤15℃ / h)" to ensure that the concrete strength meets the standard (28-day compressive strength ≥C60).

[0069] After steam curing, place the pipe pile in a cool outdoor place and cover it with a moisturizing film for 7 days to prevent the hollow microspheres from cracking inside the pipe pile due to excessive moisture loss and to ensure low thermal conductivity (thermal conductivity ≤0.8W / (m・K)).

[0070] Furthermore, the inner wall of the mold 101 of this device is provided with multiple coaxially arranged convex rings, which can form multiple coaxial anti-slip grooves on the outer surface of the formed pipe pile to improve the periphery friction resistance of the precast pipe pile. After the pipe pile is formed, a nano aerogel coating is applied to the outer surface of the pipe pile to improve the thermal conductivity of the pipe pile.

[0071] The high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device of the present invention can stir or scrape the concrete raw material on the inner wall of the concrete pipe pile according to the moisture content of the concrete raw material in the mold 101 during the centrifugal molding process of the concrete pipe pile. This can suppress the segregation of fly ash hollow microspheres, avoid powdering on the inner wall, and increase the friction of the pipe pile after processing. Furthermore, the uniform dispersion of fly ash hollow microspheres ensures low thermal conductivity of the pipe pile, while the scraping process improves the density of the inner wall, meeting the dual design requirements of "high friction + low thermal conductivity".

[0072] Based on the above embodiments, in order to improve the mixing effect of the mixing paddle 104, thereby effectively breaking the tendency of fly ash hollow microspheres to float with water due to their low density, and avoiding their enrichment and segregation on the inner wall of the pipe pile.

[0073] like Figures 2-6 As shown, the telescopic mechanism 105 includes a base 201 and a first piston 202. The base 201 is fixedly connected to the connecting shaft 103. The base 201 is provided with a sliding cavity 203, which is connected to a hydraulic control circuit. The hydraulic control circuit is electrically connected to a controller. The first piston 202 is slidably connected to the sliding cavity 203 along the radial direction of the mold 101. The stirring paddle 104 is fixedly connected to the first piston 202. The inner wall of the sliding cavity 203 is provided with a first cam groove 204. The side wall of the first piston 202 is provided with a first slider 205. The first slider 205 is slidably connected to the first cam groove 204. When the hydraulic control circuit fills the sliding cavity 203 with hydraulic oil, the first piston 202 moves away from the axis of the mold 101. Under the action of the first cam groove 204 and the first slider 205, the stirring paddle 104 rotates radially around the mold 101.

[0074] When the moisture content detector 106 detects that the real-time moisture content of the concrete in the mold 101 is higher than the preset moisture content threshold, the controller immediately sends an oil filling command to the hydraulic control circuit. The hydraulic control circuit then injects hydraulic oil into the slide cavity 203. The oil forms a stable pressure difference in the slide cavity 203, pushing the first piston 202 to move radially away from the axis along the mold 101. The first cam groove 204 preset on the inner wall of the slide cavity 203 is not a straight trajectory, but a specific curve designed according to the mixing requirements. When the first piston 202 is pushed radially by hydraulic pressure, the first slider 205 is constrained by the trajectory of the first cam groove 204. The first piston 202 synchronously rotates radially around the mold 101, and the mixing paddle 104 fixed to the first piston 202 also obtains a compound action of "radial extension + radial rotation". This allows the mixing paddle 104 to extend to cover 1 / 2-2 / 3 of the radial range inside the reinforcing cage 1 while rotating radially around the mold 101. This increases the mixing range of the mixing paddle 104, enabling two-dimensional mixing of the concrete. This improves the mixing effect of the mixing paddle 104, effectively breaking the tendency of fly ash hollow microspheres to float with moisture due to their low density, and preventing them from accumulating and segregating on the inner wall of the pipe pile. From the perspective of the motion mechanism, this ensures the mixing and anti-segregation effect of the entire device. When the moisture content meter 106 reports that the real-time moisture content of the concrete has dropped below the moisture content threshold, the controller switches to a switching command, the hydraulic control circuit depressurizes, and the mixing paddle 104 retracts and rotates in the opposite direction until the distance between the side wall of the mixing paddle 104 and the axis of the connecting shaft 103 is equal to the inner diameter of the pre-processed pipe pile. During this process, the cooperation between the first cam groove 204 and the first slider 205 ensures that the retraction action is smooth and precise. Finally, the mixing paddle 104 switches to a leveling component, which fits against the inner wall of the pipe pile. When the mold 101 rotates at high speed, it completes the leveling operation on the inner wall of the pipe pile, realizing a seamless switch between the "mixing-leveling" working conditions. This not only meets the anti-segregation requirements at high moisture content but also adapts to the flatness guarantee requirements at low moisture content, which is highly consistent with the core technical goals of pipe pile processing.

[0075] As a preferred option, such as Figure 1 , Figure 2 and Figure 4As shown, the mold 101 is rotatably connected to the support 3, and the support 3 has a sliding hole along the axial direction of the mold 101. The side wall of the connecting shaft 103 is slidably connected to the sliding hole. The driving device 102 is connected to a reciprocating mechanism, which is connected to the connecting shaft 103. When the driving device 102 drives the mold 101 to rotate, the driving device 102 drives the connecting shaft 103 to move along the axial direction of the mold 101 through the reciprocating mechanism. While driving the mold 101 to rotate, the driving device 102 also drives the connecting shaft 103 to reciprocate linearly along the axial direction of the mold 101 through the reciprocating mechanism. During the processing, the connecting shaft 103 and the stirring paddle 104 on it participate in two movements simultaneously: radial movement along the mold 101 and reciprocating movement along the axial direction of the mold 101. This significantly expands the range of action of the stirring paddle 104, enabling the stirring or leveling operation of the stirring paddle 104 to evenly cover the entire inner wall of the pipe pile and avoid local under-processing. During the high moisture content stage, the mixing paddle 104 extends and rotates while moving axially, which can more effectively disrupt the flow state inside the concrete and suppress the tendency of fly ash hollow microspheres to float to the inner wall due to their low density, thus fundamentally reducing segregation and subsequent powdering problems. During the low moisture content stage, the mixing paddle 104 retracts into a scraper and moves axially to continuously scrape the inner wall, ensuring surface flatness and density, and improving the friction performance of the pipe pile.

[0076] As a preferred option, such as Figure 1 , Figure 2 and Figure 4As shown, the hydraulic control circuit includes a cylinder 401, a second piston 402, and a reversing valve 403. The cylinder 401 is fixedly connected to the bracket 3, and the second piston 402 is fixedly connected to the connecting shaft 103. The second piston 402 is slidably connected to the inner cavity of the cylinder 401 along the axial direction of the mold 101. Hydraulic oil is provided in the inner cavity of the cylinder 401. The inner cavity of the cylinder 401 is connected to the oil inlet of the reversing valve 403. One oil outlet of the reversing valve 403 is connected to the slide cavity 203, and the other oil outlet of the reversing valve 403 is connected to the inner cavity of the cylinder 401. The reversing valve 403 is electrically connected to the controller. When the drive device 102 drives the mold 101 to rotate, the reciprocating mechanism causes the connecting shaft 103 to reciprocate axially. Since the second piston 402 is fixedly connected to the connecting shaft 103, the connecting shaft 103 drives the second piston 402 to slide back and forth in the cylinder 401, causing pressure changes in the hydraulic oil inside the cylinder 401, thus forming a hydraulic power source. When the real-time water content of the concrete is higher than the water content threshold, the controller commands the reversing valve 403 to switch to the "slide chamber 203 oil supply" state. At this time, the high-pressure hydraulic oil generated inside the cylinder 401 flows into the slide chamber 203 of the mixing mechanism through the reversing valve 403. Under the action of the reciprocating mechanism, the hydraulic oil flows back and forth in the cylinder 401 and slide chamber 203, thereby pushing the first piston 202 to reciprocate radially along the mold 101. At the same time, with the cooperation of the first cam groove 204 and the first slider 205, the mixing paddle 104 is driven to rotate back and forth, realizing the reciprocating rotation of the mixing paddle 104. The combined mixing action of "radial reciprocating extension and reciprocating rotation around mold 101" enhances the mixing effect of mixing paddle 104, effectively suppressing the segregation of fly ash hollow microspheres. When the real-time moisture content of the concrete drops below the moisture content threshold and mixing paddle 104 moves towards the axis of mold 101, the first piston 202 retracts radially along mold 101, causing mixing paddle 104 to retract synchronously until the distance between the side wall of mixing paddle 104 and the axis of connecting shaft 103 is equal to the inner diameter of the pipe pile. At this time, the controller commands the reversing valve 403 to switch to the "oil return in cylinder 401" state. The hydraulic oil in the inner cavity of cylinder 401 flows back after passing through the reversing valve 403, thereby establishing a stable pressure in the sliding cavity 203. This allows mixing paddle 104 to uniformly adhere to the inner wall along the axial direction of the pipe pile and complete the entire scraping operation as mold 101 rotates, ensuring the flatness and density of the inner wall of the pipe pile.

[0077] As a preferred option, such as Figure 1 , Figure 2 and Figure 4As shown, the reversing valve 403 is an electromagnetic reversing valve 403. When the real-time moisture content of the concrete raw material is greater than the moisture content threshold, the controller controls the reversing valve 403 to move to the inner cavity of the oil cylinder 401 and connect it to the slide cavity 203 through the reversing valve 403. When the real-time moisture content of the concrete raw material is less than the moisture content threshold and the connecting shaft 103 moves to the end away from the oil cylinder 401, so that the hydraulic oil flows back from the slide cavity 203 to the inner cavity of the oil cylinder 401, and the stirring paddle 104 retracts to the side close to the shaft of the mold 101, the controller controls the reversing valve 403 to switch to the inner cavity of the oil cylinder 401 and connect it to the inner cavity of the oil cylinder 401 through the reversing valve 403. When the real-time moisture content of the concrete is higher than the moisture content threshold, the inner cavity of the hydraulic cylinder 401 is connected to the sliding cavity 203 of the mixing mechanism through the reversing valve 403. At this time, the hydraulic oil in the hydraulic cylinder 401 flows back and forth between the sliding cavity 203 and the inner cavity of the hydraulic cylinder 401, thereby pushing the first piston 202 to reciprocate along the radial direction of the mold 101, thereby driving the mixing paddle 104 to reciprocate in extension and rotation, thereby further improving the mixing effect of the mixing paddle 104 and preventing the segregation of fly ash hollow microspheres. When the real-time moisture content of the concrete is lower than the moisture content threshold and the mixing paddle 104 retracts to the side close to the axis of the mold 101, the inner cavity of the hydraulic cylinder 401 is connected to itself through the reversing valve 403. At this time, the hydraulic oil in the inner cavity of the hydraulic cylinder 401 flows back to the inner cavity of the hydraulic cylinder 401, the mixing paddle 104 retracts to the sliding cavity 203 to maintain pressure, and the mixing paddle 104 transforms into a scraper to scrape the inner wall of the pipe pile as the mold 101 rotates. By setting the reversing valve 403 as a solenoid valve and using a controller to achieve automatic control, the coordinated control of the radial movement of the agitator 104 and the axial movement of the connecting shaft 103 is realized, resulting in a compact structure and precise control.

[0078] As a preferred option, such as Figure 5 As shown, the base 201 is provided with a slot 5, the length direction of which is parallel to the length direction of the mold 101. The slot 5 is used to lock the mixing paddle 104 after the first piston 202 retracts into the sliding cavity 203. When the concrete moisture content drops below the moisture content threshold and the mixing paddle 104 completes its retraction action, the slot 5 ensures that the mixing paddle 104 remains in a position matching the inner diameter of the pipe pile, preventing it from rotating or vibrating during high-speed rotation. This design ensures stable contact between the mixing paddle 104 and the inner wall of the pipe pile during the leveling operation, improving the consistency and reliability of the leveling effect, while reducing mechanical wear and extending the service life of the equipment.

[0079] As a preferred option, such as Figure 2 and Figure 4As shown, the sliding hole is provided with a limiting groove 601 along the axial direction of the mold 101. A limiting slider 602 is slidably connected within the limiting groove 601. The limiting groove 601 and the limiting slider 602 are used to prevent the connecting shaft 103 from rotating around the axial direction of the mold 101. The limiting groove 601 on the sliding hole and the limiting slider 602 on the connecting shaft 103 cooperate to form a guiding and anti-rotation mechanism along the axial direction of the mold 101. The limiting slider 602 can only slide axially along the limiting groove 601 and cannot rotate around the axis of the mold 101, thereby restricting the rotational freedom of the connecting shaft 103. This structure ensures that the connecting shaft 103 only performs pure axial movement, preventing it from twisting or swaying during reciprocating motion. This ensures the positional accuracy and movement stability of the mixing paddle 104 during the processing of the inner wall of the pipe pile, while reducing mechanical stress concentration and improving the operational safety of the entire device.

[0080] As a preferred option, such as Figure 1 , Figure 2 and Figure 4 As shown, the reciprocating mechanism includes a cam 701 and a drive plate 702. The cam 701 is connected to the drive device 102, and a second cam groove 703 is provided on the upper side wall of the cam 701. The drive plate 702 is fixedly connected to the connecting shaft 103, and a second slider 704 is provided at the bottom end of the drive plate 702. The second slider 704 is slidably connected in the second cam groove 703. When the drive device 102 drives the cam 701 to rotate, the drive plate 702 moves along the axial direction of the mold 101 under the drive of the second cam groove 703 and the second slider 704. When the drive device 102 drives the cam 701 to rotate, the second slider 704 slides in the second cam groove 703. The curved contour of the second cam groove 703 forces the drive plate 702 to reciprocate along the axial direction of the mold 101. This efficiently converts the rotational motion into linear reciprocating motion, allowing the connecting shaft 103 to drive the mixing mechanism to move uniformly along the length of the pipe pile. The profile of cam 701 can be precisely designed according to processing requirements to achieve different movement speeds and strokes, ensuring that the mixing or leveling operation is uniform and consistent throughout the entire length of the pipe pile.

[0081] As a preferred option, such as Figure 2 As shown, the mixing blade 104 is made of a material with a hardness of 500HB to 800HB. The mixing blade 104 is made of a high-strength material with a hardness of 500HB to 800HB, and the high hardness characteristic enables the mixing blade 104 to withstand the high stress and wear during concrete processing.

[0082] This invention also provides a method for processing pipe piles using a high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device, comprising the following steps:

[0083] According to the mixing ratio, the cementitious materials, aggregates and hollow microspheres are first dry mixed for 2-3 minutes, and then water and admixtures are added and wet mixed for 3-5 minutes to ensure that the hollow microspheres are evenly dispersed, thereby forming concrete raw materials;

[0084] After installing the reinforcing cage 1 inside the mold 101, calibrate the coaxiality between the connecting shaft 103 and the mold 101.

[0085] Debug the mixing mechanism to ensure that when the telescopic mechanism 105 extends, the mixing blade 104 covers 1 / 2 to 2 / 3 of the radial range inside the steel cage 1, and when it retracts, the distance between the side wall of the mixing blade 104 and the axis is equal to the inner diameter of the pipe pile.

[0086] Calibrate the moisture content meter 106 and set the moisture content threshold of 15%-17% in the controller;

[0087] The material is placed inside the mold 101, and then centrifuged gradually at a speed of "low-medium-high".

[0088] When the real-time moisture content of the concrete raw material is greater than or equal to the moisture content threshold, the controller commands the telescopic mechanism 105 to extend, and the mixing paddle 104 to mix the concrete raw material on the inner wall of the pipe pile as the mold 101 rotates; when the real-time moisture content of the concrete raw material is less than the moisture content threshold, the controller commands the mixing paddle 104 to retract, so that the mixing paddle 104 fits against the inner wall of the pipe pile and scrapes the inner wall of the pipe pile as the mold rotates.

[0089] After demolding, the concrete is first steam-cured and then naturally cured to ensure its compressive strength and thermal conductivity.

[0090] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device, comprising a mold, a driving device, and a connecting shaft, wherein the driving device is used to drive the mold to rotate about its own axis, and the connecting shaft is coaxially arranged with the mold, characterized in that, Also includes: The mixing mechanism includes a mixing paddle and a telescopic mechanism. The telescopic mechanism is mounted on a connecting shaft, and the mixing paddle is connected to the telescopic mechanism. The telescopic mechanism is used to drive the mixing paddle to move radially along the mold, and the mixing paddle is used to mix the concrete raw materials inside the steel cage. A moisture content meter is installed inside the mold. The moisture content meter is used to detect the real-time moisture content of concrete raw materials. The controller is electrically connected to the telescopic mechanism and the moisture content detector. The controller has a preset moisture content threshold. The controller controls the telescopic mechanism to move according to the real-time moisture content of the concrete raw materials and the moisture content threshold. When the real-time moisture content is less than the moisture content threshold, the controller controls the telescopic mechanism to contract so that the distance between the side wall of the mixing paddle and the axis of the connecting shaft is equal to the design inner diameter of the pre-processed pipe pile, and the length direction of the mixing paddle is parallel to the axis of the mold. The telescopic mechanism includes a base and a first piston. The base is fixedly connected to the connecting shaft. The base is provided with a sliding cavity, which is connected to a hydraulic control circuit. The hydraulic control circuit is electrically connected to a controller. The first piston is slidably connected to the sliding cavity along the radial direction of the mold. The stirring paddle is fixedly connected to the first piston. The inner wall of the sliding cavity is provided with a first cam groove, and the side wall of the first piston is provided with a first slider. The first slider is slidably connected to the first cam groove. When the hydraulic control circuit fills the sliding cavity with hydraulic oil, the first piston moves away from the mold axis. Under the action of the first cam groove and the first slider, the stirring paddle rotates radially around the mold. The mold is rotatably connected to the bracket, and the bracket is provided with a sliding hole along the axial direction of the mold. The side wall of the connecting shaft is slidably connected to the sliding hole. The driving device is connected to a reciprocating mechanism, and the reciprocating mechanism is connected to the connecting shaft. When the driving device drives the mold to rotate, the driving device drives the connecting shaft to move along the axial direction of the mold through the reciprocating mechanism. The hydraulic control circuit includes a hydraulic cylinder, a second piston, and a reversing valve. The hydraulic cylinder is fixedly connected to the bracket, and the second piston is fixedly connected to the connecting shaft. The second piston is slidably connected to the inner cavity of the hydraulic cylinder along the axial direction of the mold. Hydraulic oil is provided in the inner cavity of the hydraulic cylinder. The inner cavity of the hydraulic cylinder is connected to the oil inlet of the reversing valve. One oil outlet of the reversing valve is connected to the slide cavity, and the other oil outlet of the reversing valve is connected to the inner cavity of the hydraulic cylinder. The reversing valve is electrically connected to the controller.

2. The high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device as described in claim 1, characterized in that, The reversing valve is an electromagnetic reversing valve. When the real-time moisture content of the concrete raw material is greater than the moisture content threshold, the controller controls the reversing valve to move to the inner cavity of the oil cylinder and connect it to the slide cavity through the reversing valve. When the real-time moisture content of the concrete raw material is less than the moisture content threshold and the connecting shaft moves to the end away from the oil cylinder, the hydraulic oil flows back from the slide cavity to the inner cavity of the oil cylinder. When the stirring paddle retracts to the side close to the mold shaft, the controller controls the reversing valve to switch to the inner cavity of the oil cylinder and connect it to the inner cavity of the oil cylinder through the reversing valve.

3. The high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device as described in claim 2, characterized in that, The base is provided with a slot, the length direction of which is parallel to the length direction of the mold. The slot is used to lock the stirring paddle after the first piston retracts into the sliding cavity.

4. The high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device as described in claim 1, characterized in that, The sliding hole is provided with a limiting groove along the mold axis, and a limiting slider is slidably connected in the limiting groove. The limiting groove and the limiting slider are used to prevent the connecting shaft from rotating around the mold axis.

5. The high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device as described in claim 3, characterized in that, The reciprocating mechanism includes a cam and a drive plate. The cam is connected to the drive device. A second cam groove is provided on the upper side wall of the cam. The drive plate is fixedly connected to the connecting shaft. A second slider is provided at the bottom end of the drive plate. The second slider is slidably connected in the second cam groove. When the drive device drives the cam to rotate, the drive plate moves along the axial direction of the mold under the drive of the second cam groove and the second slider.

6. The high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device as described in claim 1, characterized in that, The agitator is made of a material with a hardness of 500HB to 800HB.

7. A method for processing pipe piles using the high-friction, low-thermal-conductivity prestressed concrete pipe pile processing device as described in claim 1, characterized in that, Includes the following steps: According to the mixing ratio, the cementitious materials, aggregates and hollow microspheres are first dry mixed for 2-3 minutes, and then water and admixtures are added and wet mixed for 3-5 minutes to ensure that the hollow microspheres are evenly dispersed, thereby forming concrete raw materials; After installing the reinforcing cage inside the mold, calibrate the coaxiality between the connecting shaft and the mold. Debug the mixing mechanism to ensure that when the telescopic mechanism extends, the mixing blade covers 1 / 2 to 2 / 3 of the radial range inside the steel cage, and when it retracts, the distance between the side wall of the mixing blade and the axis is equal to the inner diameter of the pipe pile. Calibrate the moisture content meter and set the moisture content threshold of 15%-17% in the controller; The material is placed inside the mold, and then centrifuged gradually at a speed of "low-medium-high". When the real-time moisture content of the concrete raw material is greater than or equal to the moisture content threshold, the controller commands the telescopic mechanism to extend, and the mixing paddle stirs the concrete raw material on the inner wall of the pipe pile as the mold rotates; when the real-time moisture content of the concrete raw material is less than the moisture content threshold, the controller commands the mixing paddle to retract, so that the mixing paddle fits against the inner wall of the pipe pile and scrapes the inner wall of the pipe pile as the mold rotates. After demolding, the concrete is first steam-cured and then naturally cured to ensure its compressive strength and thermal conductivity.

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