Environment-friendly high-strength concrete precast pipe pile based on recycled residual slurry and preparation method

Abstract

The application discloses an environment-friendly high-strength concrete precast pipe pile based on recycled surplus slurry, the pipe pile comprises a steel reinforcement cage and a concrete slurry wrapped on the steel reinforcement cage, and the concrete slurry is shaped into the pipe pile after solidification; the concrete slurry comprises aggregates, cementitious materials, water reducing agents and surplus slurry used for replacing water. The application realizes accurate calculation of concrete slurry proportioning when surplus slurry is recycled, ensures the quality reliability of the concrete slurry, and solves the problem of unstable performance of the concrete slurry caused by performance differences of the surplus slurry.

Description

[0001] This application is a divisional application of Chinese invention patent application filed on December 24, 2025, with application number 2025119600513 and invention title "An Environmentally Friendly High-Strength Concrete Precast Pipe Pile Based on Recycled Residue and Preparation Method Thereof". Technical Field

[0002] This application provides an environmentally friendly high-strength precast concrete pipe pile based on recycled slurry and its preparation method, which relates to the field of building engineering technology. Background Technology

[0003] Prestressed concrete precast pipe piles are an important pile foundation material, widely used in engineering projects such as bridges, highways, railways, airports, and ports. The use of precast pipe piles effectively shortens construction time, makes construction sites cleaner and more environmentally friendly, and saves significant amounts of materials and energy. Precast piles are widely used in engineering construction and have a promising market prospect.

[0004] Currently, 80% of precast pipe piles in the market are produced using centrifugal molding. Centrifugation generates a large amount of waste slurry, which needs to be dumped after the pipe piles are centrifuged. With the continuous increase in market demand, the production volume of precast pipe piles is constantly increasing, and the amount of waste slurry dumped after centrifugation is also increasing, leading to environmental pollution and damage to land resources.

[0005] To achieve the recycling and reuse of waste slurry, Chinese patent document CN116238041A provides a concrete waste slurry recycling and reuse system and its control method, which recycles waste slurry and homogenizes it into reusable waste slurry. Chinese patent document CN120157414A provides a waste slurry recycling formula, which adds waste slurry to new cement in a preset amount for recycling and reuse.

[0006] Precise proportioning of concrete slurry requires long-term testing based on application scenarios and is a core technology for every manufacturer. To incorporate residual slurry into the concrete slurry composition, adjustments to the precise proportions are necessary to achieve a concrete slurry specifically designed for residual slurry recycling. The solids content of the residual slurry affects its performance and ultimately the performance of the recycled concrete slurry. Currently, existing concrete slurry proportions for residual slurry recycling are pre-set and cannot be precisely adjusted based on the solids content, leading to unstable performance of the resulting concrete slurry. Summary of the Invention

[0007] The technical problem to be solved by this application is the instability of concrete slurry performance caused by the difference in residual slurry properties.

[0008] To address the aforementioned technical problems, the technical solution of this application is to provide an environmentally friendly high-strength precast concrete pipe pile based on recycled residual slurry. The pipe pile includes a steel reinforcement cage and concrete slurry encasing the steel reinforcement cage. After the concrete slurry solidifies, it is formed into the pipe pile. The concrete slurry contains residual slurry containing aggregates, cementitious materials, water-reducing agents, and alternative water.

[0009] The aggregate includes sand and gravel, and the cementitious material includes cement and admixtures; the precise mix proportion of concrete slurry suitable for environmentally friendly high-strength precast concrete pipe piles is set as follows:

[0010]

[0011] Among them, the moisture content of sand is wc1, the moisture content of gravel is wc2, the solid content of residual slurry is sc1, and the solid content of water-reducing agent solution is sc2.

[0012] A residual slurry density collection point is set at the outlet of the residual slurry transported to the mixing plant. The residual slurry density d is collected and measured at this point. The real-time residual slurry solid content sc1 is calculated based on the residual slurry density d.

[0013] In concrete slurry, residual slurry is used to replace water. When the real-time residual slurry solids content deviates from the preset residual slurry solids content by more than a set threshold, the latest residual slurry solids content is adopted, and the actual usage of residual slurry and each component is calculated based on the precise concrete slurry mix proportions.

[0014]

[0015] The final concrete slurry is prepared based on the actual amounts of admixtures, cement, water-reducing agent solution, wet sand, wet stone, and residual slurry.

[0016] Preferably, the admixtures, cement, water-reducing agent solution, wet sand, wet stone, and residual slurry in the concrete slurry undergo a chemical reaction under a preset environment to produce hydrated calcium silicate crystals with a velvety edge structure and pores.

[0017] This application also provides a method for preparing environmentally friendly high-strength precast concrete pipe piles based on recycled slurry, including the following steps:

[0018] S110 Collect the waste slurry after centrifuging the precast pipe piles, add a modifier to the waste slurry and homogenize it to obtain the residual slurry;

[0019] S120 The residual slurry, admixtures, cement, water-reducing agent solution, wet sand, and wet stone are transported to the mixing plant for mixing according to the preset actual usage ratio to form the concrete slurry;

[0020] S130 The concrete slurry is poured into a mold with a steel reinforcement frame for molding to form a precast pipe pile.

[0021] Preferably, the modifier comprises the following components by weight:

[0022] 20 to 50 parts of PCE-type organic polymer, 5 to 30 parts of polyhydroxy polymer, 5 to 20 parts of amide surfactant and 20 to 50 parts of water.

[0023] Preferably, the PCE-type organic polymer is formed by free radical polymerization of the first and second substances, and the amide surfactant is generated by copolymerization of any three of acrylamide AM, 2-acrylamide-2-methylpropanesulfonic acid AMPS, acrylic acid, and allyl polyoxyethylene ether.

[0024] The first substance is one of acrylic acid, maleic anhydride, hydroxyethyl acrylate and hydroxypropyl acrylate, and the second substance is one of allyl polyoxyethylene ether, methyl allyl alcohol polyoxyethylene ether, isopentenyl alcohol polyoxyethylene ether and methyl allyl polyethylene glycol.

[0025] Preferably, the modifier includes a retarder and an antifoaming agent.

[0026] Preferably, the retarder includes sugars, other carbohydrates, or hydroxycarboxylic acids, and the defoamer includes silicone oil, polyether, higher alcohols, mineral oil, and vegetable oil.

[0027] Preferably, step S110 includes:

[0028] S111 The waste slurry is input into the homogenization tank. The liquid level of the waste slurry in the homogenization tank is detected in real time by a laser rangefinder sensor, and the volume of the waste slurry in the homogenization tank is calculated in real time based on the liquid level.

[0029] S112 The weight of the waste slurry in the homogenization tank is detected in real time by a weight detector, and the solid content of the waste slurry in the homogenization tank is calculated based on the volume and weight of the waste slurry in the homogenization tank.

[0030] S113 The waste slurry in the homogenization tank is stirred, and water is added during the stirring process so that the solid content of the waste slurry reaches the set value to obtain residual slurry.

[0031] Preferably, step S120 includes:

[0032] S121 Set up a residual slurry density collection point at the outlet of the residual slurry transported to the mixing plant, and collect the residual slurry at this point to measure the residual slurry density d;

[0033] S122 Calculate the real-time solids content sc1 of the residual slurry based on the residual slurry density d;

[0034] S123 Calculate the actual amount of residual slurry and each component based on the real-time residual slurry solids content.

[0035] This application provides an environmentally friendly high-strength precast concrete pipe pile based on recycled slurry and its preparation method. It realizes the accurate calculation of concrete slurry mix ratio when recycling slurry, ensures the reliability of concrete slurry quality, and solves the problem of unstable concrete slurry performance caused by the difference in slurry performance. Attached Figure Description

[0036] Figure 1 A schematic diagram illustrating the steps of the preparation method for environmentally friendly high-strength precast concrete pipe piles based on recycled slurry, as provided in the embodiments of this application;

[0037] Figure 2 This is a schematic diagram of the waste slurry recycling process;

[0038] Figure 3 This is a schematic diagram of a concrete residue recycling and reuse system. Detailed Implementation

[0039] To make this application more apparent and understandable, various exemplary embodiments will be described below. These examples are non-limiting and should be understood as illustrating aspects of the broader application of the apparatus, system, and method. These embodiments can be varied and substituted with equivalents without departing from the spirit and scope of this application. Furthermore, various variations can be made to adapt to specific circumstances, materials, material compositions, processing types, processing actions, or steps to suit the purpose, content, or scope of this application. All such variations will be within the protection scope of this application.

[0040] Any materials, dimensions, or quantities described in the overview or detailed description are merely examples and are not intended to limit the subject matter of this application. Furthermore, the various implementations of the embodiments described herein are complementary rather than purely alternating, unless otherwise stated. In other words, implementations from one embodiment can be freely combined with implementations from other embodiments, as will readily be apparent to those skilled in the art, unless these implementations are stated to be used only as substitutions.

[0041] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] Example

[0044] This application provides an environmentally friendly high-strength precast concrete pipe pile based on recycled grout. The pipe pile includes a steel reinforcement cage and concrete grout wrapping the steel reinforcement cage. The concrete grout solidifies and forms the pipe pile.

[0045] The concrete slurry comprises aggregates, cementitious materials, water-reducing agents, and residual slurry containing alternative water.

[0046] By recycling and reusing residual slurry, we can avoid the pollution of the environment and the destruction of land resources caused by the discharge of waste slurry. At the same time, the reuse of residual slurry can also save materials required for the preparation of precast pipe piles and reduce the preparation cost.

[0047] The aggregates include sand and gravel, and the cementitious materials include cement and admixtures.

[0048] The concrete slurry mix ratio suitable for environmentally friendly high-strength precast concrete pipe piles is set as follows:

[0049]

[0050] Among them, the moisture content of sand is wc1, the moisture content of gravel is wc2, the solid content of residual slurry is sc1, and the solid content of water-reducing agent solution is sc2.

[0051] Among them, admixtures generally include active and inactive mineral admixtures, such as industrial by-products and natural mineral materials such as fly ash, slag powder, and silica fume, which are used to optimize concrete performance and utilize industrial solid waste resources.

[0052] High-strength concrete generally refers to C80 grade and above concrete. The original mix ratio of concrete slurry for environmentally friendly high-strength concrete precast pipe piles needs to be initially calculated, trial mixed and adjusted, and repeatedly tested to obtain the precise mix ratio used in the final pipe pile product. Precise mix ratio is the core technology of each manufacturer.

[0053] The process for obtaining the original mix proportion of concrete slurry suitable for environmentally friendly high-strength precast concrete pipe piles in this embodiment includes:

[0054] Preliminary calculations, based on national design specifications for high-strength concrete, determine the initial proportions (material usage per cubic meter) of aggregates, cementitious materials, and water-reducing agents, as well as the water-cement ratio.

[0055] Trial mixing, adjustment, and testing: Initially mix test concrete according to the original mix proportions, testing slump, cohesion, and water retention. If the slump is too low, increase the amount of water and cementitious materials, or increase the amount of admixtures, while maintaining the water-cement ratio. If the slump is too high, reduce the amount of water and cementitious materials, or reduce the amount of admixtures. If cohesion is poor or there is bleeding, appropriately increase the sand ratio. After several trial mixing and adjustments, until the workability fully meets the requirements, the mix proportion at this point is called the reference mix proportion. Mix test concrete according to the reference mix proportion, and mold it into precast pipe piles with a reinforced steel frame. After standard curing, measure the performance of the pipe piles, including bearing strength and durability. Adjust the reference mix proportion to make the pipe piles meet the quality requirements; this mix proportion is called the laboratory mix proportion. Since the sand and gravel used in the laboratory mix proportion are theoretically dry sand and gravel, the sand and gravel actually used may be wet sand or wet gravel. The mix proportion calculated based on the sand moisture content wc1 and the gravel moisture content wc2 is the construction mix proportion.

[0056] This construction mix ratio is the precise proportion of materials added to the specific mixer.

[0057] The recycling method used in this application involves replacing water with residual slurry in the concrete slurry, and calculating the actual usage of residual slurry and each component based on the precise proportions of the concrete slurry:

[0058]

[0059] The final concrete slurry is prepared based on the actual amounts of admixtures, cement, water-reducing agent solution, wet sand, wet stone, and residual slurry.

[0060] Taking a specific and precise mix ratio actually used in the factory as an example, the calculation process for the concrete slurry dosage ratio based on the recycling of residual slurry is shown in the table below:

[0061]

[0062]

[0063] It is understandable that the solid content of the residual slurry, sc1, is not a fixed constant and is affected by the residual slurry recycling equipment. Therefore, before each use of the residual slurry, it is necessary to measure the solid content of the residual slurry, sc1, and adjust the actual amount of each component of the concrete slurry according to the real-time solid content of the residual slurry, so as to obtain a pipe pile product with better quality.

[0064] During the molding and curing process of pipe piles, the admixtures, cement, water-reducing agent solution, wet sand, wet stone, and residual slurry in the concrete slurry undergo a chemical reaction under a preset environment to produce hydrated calcium silicate crystals with a velvety edge structure and pores. For high-strength precast concrete pipe pile products, the preset environment is a saturated steam environment of 50 to 90 degrees Celsius. The formed hydrated calcium silicate crystals do not have a fixed shape, and the pores are micropores.

[0065] Using the concrete slurry mix proportion for residual slurry recycling provided in the embodiments of this application, compared with mixing with water and no residual slurry, the residual slurry can be recycled to save about 10 kg to 30 kg of cementitious materials and about 50 kg to 100 kg of sand per cubic meter of concrete, and the concrete strength grade can reach C95 or above.

[0066] like Figure 1 As shown, this application also provides a method for preparing the above-mentioned environmentally friendly high-strength precast concrete pipe pile based on recycled slurry, comprising the following steps:

[0067] S110 collects the waste slurry after centrifugation of precast pipe piles, adds a modifier to the waste slurry and homogenizes it to obtain residual slurry.

[0068] S120 transports the excess slurry, admixtures, cement, water-reducing agent solution, wet sand, and wet stone to the mixing plant according to the preset actual usage ratio for mixing to form concrete slurry.

[0069] Specifically, the residual slurry, admixtures, cement, water-reducing agent solution, wet sand, and wet stone are mixed according to the preset actual usage ratio and calculation as described above, and then stirred at the mixing plant.

[0070] S130 involves filling concrete slurry into a pipe pile mold with a steel reinforcement skeleton to form a precast pipe pile.

[0071] Specifically, the steel reinforcement cage, pipe pile mold, and pipe pile forming process are all common knowledge in this field and will not be elaborated here.

[0072] It is understandable that waste slurry will be generated during the pipe pile forming process in step S130. The waste slurry collected in step S110 is the waste slurry generated during the pipe pile forming process. It can be the waste slurry generated during the pipe pile forming process of recycling the residual slurry mentioned above, or the waste slurry generated during the pipe pile forming process of not recycling the residual slurry.

[0073] Using the above-described preparation method, the waste slurry generated during the production of precast pipe piles can be reused, avoiding environmental pollution and land resource damage caused by waste slurry discharge. Furthermore, the reuse of waste slurry can save materials required for precast pile preparation and reduce manufacturing costs.

[0074] In some embodiments, the preparation method further includes the step of:

[0075] S140 is used to cure the precast pipe piles after they have been formed.

[0076] Specifically, the temperature in the curing tank is controlled between 60 and 90 degrees Celsius, and the curing time is between 3 and 10 hours.

[0077] S150 removes the mold from the curing pool and demolds it. After demolding, the finished pipe piles, i.e., precast pipe piles, are stacked in the preset position.

[0078] It is understandable that the forming and maintenance processes of pipe piles are common knowledge in this field, and will not be elaborated here.

[0079] In some embodiments, the modifier added to the waste slurry collected in S110 includes an organic polymer of the PCE (perchlorethylene) type, a polyhydroxy polymer, an amide surfactant, and water. The PCE-type organic polymer comprises 20 to 50 parts by weight, the polyhydroxy polymer comprises 5 to 30 parts, the amide surfactant comprises 5 to 20 parts, and the water comprises 20 to 50 parts.

[0080] In practical applications, PCE-type organic polymers are formed by free radical polymerization of the first and second substances, and amide surfactants are generated by copolymerization of any three of acrylamide AM, 2-acrylamido-2-methylpropanesulfonic acid AMPS, acrylic acid, and allyl polyoxyethylene ether.

[0081] The first substance is one of acrylic acid, maleic anhydride, hydroxyethyl acrylate and hydroxypropyl acrylate, and the second substance is one of allyl polyoxyethylene ether, methyl allyl alcohol polyoxyethylene ether, isopentenyl alcohol polyoxyethylene ether and methyl allyl polyethylene glycol.

[0082] In other embodiments, the modifier includes a retarder and an antifoamer.

[0083] The retarder includes sugars, other carbohydrates, and hydroxy acids, while the defoamer includes silicone oil, polyether, higher alcohols, mineral oil, and vegetable oil.

[0084] It should be explained that the modifier in the above embodiments is used to dilute the viscosity and slow down the solidification rate of the remaining slurry.

[0085] Please see Figure 2 In some embodiments, step S110 includes:

[0086] S111, waste slurry is fed into the homogenization tank. The liquid level of the waste slurry in the homogenization tank is detected in real time by a laser rangefinder sensor, and the volume of the waste slurry in the homogenization tank is calculated in real time based on the liquid level.

[0087] Specifically, the waste slurry in the first storage tank is pumped to the homogenization tank of the homogenization mechanism by a first transfer pump. At the same time, the liquid level of the waste slurry in the homogenization tank is detected, and then the volume of the waste slurry can be calculated based on the radial dimension of the homogenization tank.

[0088] S112, the weight of the waste slurry in the homogenization tank is detected in real time by a weight detector, and the solid content of the waste slurry in the homogenization tank is calculated based on the volume and weight of the waste slurry in the homogenization tank.

[0089] S113, the waste slurry in the homogenization tank is stirred, and water is added during the stirring process to make the solid content of the waste slurry reach the set value, forming the aforementioned residual slurry.

[0090] Specifically, the weight of the homogenization tank is detected by a weight detector. The weight detector can first detect the weight of the homogenization tank when it is empty, and then detect the weight of the homogenization tank again after the waste slurry is added. Then, the weight of the waste slurry can be obtained by subtracting the empty weight from the weight after the waste slurry is added.

[0091] It is understandable that the slurry contains both solids and water. The density of water is known. Since the solids in the slurry increase its density, the solid content of the slurry can be calculated.

[0092] There are two methods for calculating the solids content of residual slurry:

[0093] One method is actual sampling, which involves taking a unit weight of residual slurry, evaporating the water, and then measuring the solid weight. The solid content of the residual slurry = solid weight / unit weight.

[0094] Another method is to convert using an empirical formula. There is an approximate linear relationship between the solid content of residual slurry and the specific gravity of residual slurry (the reciprocal of the density of residual slurry): solid content of residual slurry = 144.77 - 140.85 / density of residual slurry. This linear relationship was obtained by fitting data from multiple actual measurements of solid content and specific gravity of residual slurry.

[0095] As mentioned above, in practical applications, the solids content of the waste slurry is set to 48% to 55%. The initial waste slurry has a high solids content. Water is slowly added during the mixing process, and the density change of the waste slurry is monitored in real time to calculate the solids content of the waste slurry. Usable waste slurry is obtained when the solids content of the waste slurry reaches the set value range.

[0096] In actual production, it has been found that the solids content of the residual slurry changes during the process of transporting it to the mixing plant due to reasons such as pipeline leakage or residual fixing objects in the pipeline. Therefore, in some embodiments, step S120 includes:

[0097] S121 Set up a residual slurry density collection point at the outlet of the residual slurry transported to the mixing plant, and collect the residual slurry at this point to measure the residual slurry density d;

[0098] S122 Calculate the real-time solids content sc1 of the residual slurry based on the residual slurry density d;

[0099] S123 Calculate the actual amount of residual slurry and each component based on the real-time residual slurry solids content.

[0100] The measurement methods for residual slurry density sampling points in step S121 include two types:

[0101] One method is to actually sample the residual slurry, measure the volume of the residual slurry by taking a unit weight of the residual slurry, and then calculate the density d of the residual slurry.

[0102] Another option is to install a density sensor here, such as a straight pipe density sensor from Worldcom or Comer. The density d of the residual slurry can be measured in real time by passing the residual slurry through the straight pipe density sensor at a constant speed.

[0103] Step S123 can set a threshold (2%) for the deviation rate of residual slurry solids content. When the deviation between the real-time residual slurry solids content and the preset residual slurry solids content exceeds the set threshold, the latest residual slurry solids content should be used according to the original accurate mix ratio of concrete slurry suitable for environmentally friendly high-strength precast pipe piles provided above, and the actual usage of residual slurry and each component should be calculated based on the original mix ratio of concrete slurry, so as to obtain a more accurate residual slurry and the actual usage of each component, and ensure the quality of concrete slurry.

[0104] For a concrete slurry recycling and reuse system suitable for recovering slurry, please refer to Chinese patent document CN116238041A, which discloses a concrete slurry recycling and reuse system and its control method. Figure 3 (Cited from CN116238041A) Figure 1 The concrete slurry recycling system includes a slurry collection mechanism 1, a slurry homogenization mechanism 2, and a slurry storage and conveying mechanism 3. The slurry is conveyed to the concrete mixer through the slurry storage and conveying mechanism 3 to achieve slurry reuse.

[0105] The waste slurry collection mechanism is used to collect the waste slurry generated after the pipe pile is formed. The homogenization mechanism is used to homogenize the waste slurry to form usable waste slurry. The waste slurry storage and conveying mechanism is used to store the waste slurry and convey it to the mixer. The mixer is used to obtain the waste slurry, cementitious materials, aggregates and water-reducing agents and mix them to form concrete. The mixer is also used to temporarily store the concrete and output the concrete into the pipe pile mold when needed to prepare the pipe pile.

[0106] It is understood that, in order to realize the environmentally friendly high-strength precast concrete pipe piles and preparation method using recycled slurry protected in this application, a concrete slurry recycling system, a mixer, and a mixer control system are required. The concrete slurry recycling system transforms waste slurry into usable slurry; the mixer and its control system ensure precise feeding of aggregates, cementitious materials, water-reducing agents, and slurry in appropriate quantities, and prepares the concrete slurry; the pipe pile forming system and process transform the concrete slurry into formed pipe piles. It should be understood that the concrete slurry recycling system, the mixer and its control system, and the pipe pile forming system and process are all prior art; for any omissions, please refer to existing technical documents.

[0107] The above description is merely a preferred embodiment of this application and does not constitute any limitation on this application in any form or substance. It should be noted that those skilled in the art can make several improvements and additions without departing from this application, and these improvements and additions should also be considered within the scope of protection of this application. Any modifications, alterations, and equivalent variations made by those skilled in the art based on the disclosed technical content without departing from the content and scope of this application are equivalent embodiments of this application. Furthermore, any equivalent changes, alterations, and variations made to the above embodiments based on the essential technology of this application still fall within the scope of the technical solution of this application.

Claims

1. An environmentally friendly high-strength precast concrete pipe pile based on recycled slurry, characterized in that, The pipe pile includes a steel reinforcement cage and concrete grout covering the steel reinforcement cage. The concrete grout solidifies and forms the pipe pile. The concrete grout contains aggregate, cementitious materials, water-reducing agent and residual grout with alternative water. The aggregate includes sand and gravel, and the cementitious material includes cement and admixtures; the precise mix proportion of concrete slurry suitable for environmentally friendly high-strength precast concrete pipe piles is set as follows: Among them, the moisture content of sand is wc1, the moisture content of gravel is wc2, the solid content of residual slurry is sc1, and the solid content of water-reducing agent solution is sc2. A residual slurry density collection point is set at the outlet of the mixing plant to measure the residual slurry density d; the real-time residual slurry solids content sc1 is calculated based on the residual slurry density d; the residual slurry is used to replace water in the concrete slurry; when the real-time residual slurry solids content deviates from the preset residual slurry solids content by more than a set threshold, the latest residual slurry solids content is adopted, and the actual usage of residual slurry and each component is calculated based on the accurate concrete slurry mix proportion: The final concrete slurry is prepared based on the actual amounts of admixtures, cement, water-reducing agent solution, wet sand, wet stone, and residual slurry.

2. The environmentally friendly high-strength precast concrete pipe pile based on recycled slurry according to claim 1, characterized in that, The admixtures, cement, water-reducing agent solution, wet sand, wet stone, and residual slurry in the concrete slurry undergo a chemical reaction under a preset environment to produce hydrated calcium silicate crystals with a velvety edge structure and pores.

3. A method for preparing environmentally friendly high-strength precast concrete pipe piles based on recycled slurry as described in any one of claims 1-2, characterized in that, Including the following steps: S110 Collect the waste slurry after centrifuging the precast pipe piles, add a modifier to the waste slurry and homogenize it to obtain the residual slurry; S120 The residual slurry, admixtures, cement, water-reducing agent solution, wet sand, and wet stone are transported to the mixing plant for mixing according to the preset actual usage ratio to form the concrete slurry; S130 The concrete slurry is poured into a mold with a steel reinforcement frame for molding to form a precast pipe pile.

4. The preparation method according to claim 3, characterized in that, The modifier comprises the following components by weight: 20 to 50 parts of PCE-type organic polymer, 5 to 30 parts of polyhydroxy polymer, 5 to 20 parts of amide surfactant and 20 to 50 parts of water.

5. The preparation method according to claim 4, characterized in that, The PCE-type organic polymer is formed by free radical polymerization of the first and second substances, and the amide surfactant is formed by copolymerization of any three of acrylamide AM, 2-acrylamide-2-methylpropanesulfonic acid AMPS, acrylic acid, and allyl polyoxyethylene ether. The first substance is one of acrylic acid, maleic anhydride, hydroxyethyl acrylate and hydroxypropyl acrylate, and the second substance is one of allyl polyoxyethylene ether, methyl allyl alcohol polyoxyethylene ether, isopentenyl alcohol polyoxyethylene ether and methyl allyl polyethylene glycol.

6. The preparation method according to claim 3, characterized in that, The modifiers include retarders and defoamers.

7. The preparation method according to claim 6, characterized in that, The retarder includes sugars, other carbohydrates, or hydroxycarboxylic acids, and the defoamer includes silicone oil, polyether, higher alcohols, mineral oil, and vegetable oil.

8. The preparation method according to claim 3, characterized in that, Step S110 includes: S111 The waste slurry is input into the homogenization tank. The liquid level of the waste slurry in the homogenization tank is detected in real time by a laser rangefinder sensor, and the volume of the waste slurry in the homogenization tank is calculated in real time based on the liquid level. S112 The weight of the waste slurry in the homogenization tank is detected in real time by a weight detector, and the solid content of the waste slurry in the homogenization tank is calculated based on the volume and weight of the waste slurry in the homogenization tank. S113 The waste slurry in the homogenization tank is stirred, and water is added during the stirring process so that the solid content of the waste slurry reaches the set value to obtain residual slurry.

9. The preparation method according to claim 8, characterized in that, Step S120 includes: S121 Set up a residual slurry density collection point at the outlet of the residual slurry transported to the mixing plant, and collect the residual slurry at this point to measure the residual slurry density d; S122 Calculate the real-time solids content sc1 of the residual slurry based on the residual slurry density d; S123 Calculate the actual amount of residual slurry and each component based on the real-time residual slurry solids content.

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