Low-carbon high-strength corrosion-resistant pipe pile and preparation method thereof

Abstract

This invention belongs to the field of building engineering technology and relates to a low-carbon, high-strength, corrosion-resistant pipe pile and its preparation method. The key technical points are as follows: It comprises the following components in parts by weight: 5.5-6.5 parts composite admixture; 0.05-0.2 parts corrosion inhibitor; 13-15 parts cement; 25-30 parts manufactured sand; 50-55 parts crushed stone; 0.1-0.3 parts high-performance water-reducing agent; and 4-6 parts water. This invention uses composite admixtures to replace cement, producing low-carbon, high-strength, and corrosion-resistant concrete with a strength grade of C100. This significantly reduces the amount of cement used in high-strength concrete, eliminates the need for autoclaving during molding, improves the corrosion resistance of manufactured sand high-strength concrete, achieves the goal of low-carbon, high-strength, and corrosion-resistant concrete, and reduces cement usage, resulting in significant economic and environmental benefits.

Description

Technical Field

[0001] This invention belongs to the field of building engineering technology, and in particular relates to a low-carbon, high-strength, corrosion-resistant pipe pile and its preparation method. Background Technology

[0002] Concrete pipe piles are an important building component for foundation treatment and pile foundation construction. Due to their high bearing capacity, quick and convenient construction, short construction period, and economic and environmental benefits, they are widely used in high-rise buildings, bridges, highways and railways, and large and important port terminals. Traditionally, concrete pipe piles are produced using a two-stage steam curing process: first, atmospheric pressure steam curing, followed by high-pressure steam curing. Atmospheric pressure steam curing is carried out at 80℃~95℃, while high-pressure steam curing is carried out under pressure at 0.9MPa~1.0MPa and 170℃~180℃.

[0003] Although secondary curing can bring concrete pipe piles to their factory strength within a curing cycle, it has drawbacks such as high energy consumption, poor pile durability, and significant safety hazards. High-pressure steam curing requires specialized equipment, which is complex to install and requires careful maintenance, posing significant production safety risks. Furthermore, it consumes large amounts of non-renewable natural resources such as coal, oil, and natural gas, increasing costs. Additionally, the concrete in concrete pipe piles is brittle, and during actual construction, the surface concrete is prone to spalling, even leading to pile breakage. Therefore, ensuring the strength and durability of concrete pipe piles without omitting the high-pressure steam curing process is a pressing technical problem that needs to be solved.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the present invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The first objective of this invention is to provide a low-carbon, high-strength, corrosion-resistant pipe pile. This is achieved by replacing cement with composite admixtures and adding corrosion inhibitors to prepare concrete pipe piles that meet the requirements of low carbon, high strength, and corrosion resistance. This improves the corrosion resistance of manufactured sand high-strength concrete, achieving the goal of low carbon, high strength, and corrosion resistance, while reducing cement usage in the preparation of high-strength concrete, thus realizing significant economic and environmental benefits.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: 5.5-6.5 parts of composite admixture; 0.05-0.2 parts of corrosion inhibitor; 13-15 parts of cement; 25-30 parts of manufactured sand; 50-55 parts of crushed stone; 0.1-0.3 parts of high-performance water-reducing agent; 4-6 parts of water.

[0007] Preferably, the composite admixture includes ultrafine fly ash, silica fume, and Class I fly ash, with a mixing ratio of 1~2:0.8~1:0.8~1. The properties of the composite admixture are shown in the table below: Performance of composite admixtures

[0008] Both silica fume and fly ash are solid wastes generated in industrial production. Using them as admixtures in concrete allows for resource utilization. The fineness of Grade I fly ash refers to a residue of no more than 12% on a 45μm square-hole sieve and a specific surface area of ​​350~400m². 2 / kg, the specific surface area of ​​ultrafine fly ash is 800~1000 m² 2 / kg; the silica fume has a SiO2 content greater than 85% and a specific surface area of ​​15,000~20,000 m². 2 / kg, with a bulk density of 600~620kg / m³ 3 The apparent density is 2100~2180 kg / m³ 3 The 3-day activity index is 100%, and the 28-day activity index is 110%. The particle size distribution ranges of ultrafine fly ash, silica fume, and Class I fly ash are different. After blending, they form a composite admixture with continuous particle size distribution and the densest packing.

[0009] Preferably, the corrosion inhibitor comprises the following components in parts by weight: 20-30 parts of antifoaming polymer; 10-20 parts of polymer material additives; 10-25 parts of stabilizing adhesive; 15-25 parts of preservative.

[0010] This invention mixes antifoaming polymers, polymeric material additives, stabilizing binders, and corrosion inhibitors in a specific ratio to create a corrosion inhibitor. This corrosion inhibitor, as a compound surfactant, is added to concrete to effectively eliminate and inhibit the formation of large air bubbles, improve the early strength of concrete, and reduce the amount of air bubbles in the concrete mixture. In the concrete mixture, the corrosion inhibitor reduces the surface tension of the liquid phase, destroying existing air bubbles and further reducing the total amount of air bubbles. This reduces the pore size of the concrete, increases its density, improves its resistance to the intrusion of poor water quality, improves its performance, inhibits the rate of calcium hydroxide precipitation from cement paste, slows down the rate of sulfate attack, and improves the surface layer of the concrete, resulting in good performance in practical applications. The corrosion inhibitor has special surface chemical properties and a high specific surface area, enabling it to adsorb and neutralize harmful chemicals, forming a protective layer to prevent harmful substances from eroding the concrete. Furthermore, it promotes the hardening and early strength development of concrete by increasing the chemically reactive surface area, forming calcium-based nanocrystals, creating a bridging effect, and improving conductivity.

[0011] Preferably, the defoaming polymer is one or more of polydimethylsiloxane and aminopropyl silicone oil. Defoaming polymers have low surface tension, which can reduce the air bubble content in concrete, and they also have the characteristics of participating in the reaction for a longer period of time and being safe and non-toxic.

[0012] As a preferred polymer material additive, 1-ethoxy-1-trimethylsiloxycyclopropane is used. 1-Ethoxy-1-trimethylsiloxycyclopropane is structurally polar, a high-boiling-point, non-volatile liquid with good miscibility with polymers. It can reduce the molecular forces between cement particles and aggregates, thereby reducing the viscosity of the concrete mixture, increasing its flexibility, improving the performance of concrete materials, reducing production costs, and increasing production efficiency.

[0013] Preferably, the stabilizing binder is one or more of isostearyl isostearate, mono- and diglyceride fatty acid esters, and 3-hydroxy-N-(2-methoxyphenyl)-2-naphthylcarboxamide. The stabilizing binder acts as an auxiliary support for the antifoaming polymer, enabling rapid penetration or integration of the antifoaming polymer and polymeric additives, improving the stability of both the antifoaming polymer and the polymeric additives, enhancing the stability of the corrosion inhibitor, and effectively preventing damage from microorganisms and bacteria, thereby ensuring the performance of the concrete.

[0014] Preferred corrosion inhibitor is multi-walled carbon nanotubes (MWCNTs). The function of the corrosion inhibitor is to improve the early strength of concrete and enhance its resistance to chloride ion penetration and corrosion. MWCNTs possess unique surface chemistry and a high specific surface area, enabling them to adsorb and neutralize harmful chemicals, forming a protective layer that prevents these substances from eroding the reinforcing steel and cement matrix of the concrete. As a corrosion inhibitor, MWCNTs in concrete primarily promote hardening and early strength development by increasing the chemically reactive surface area, forming calcium-based nanocrystals, creating a bridging effect, and improving electrical conductivity.

[0015] As a preferred choice, the cement is P·O 52.5 pile cement.

[0016] Preferably, the manufactured sand is a mixture of coarse-grained sand, medium-grained sand and fine-grained sand in a weight ratio of 2~3:4~5:2~3, with the coarse-grained sand having a particle size of 1.18-0.6mm; the medium-grained sand having a particle size of 0.6-0.3mm; and the fine-grained sand having a particle size of 0.3-0.15mm.

[0017] Preferably, the crushed stone has a particle size range of 5–20 mm, a crushing index of less than 8%, and a mud content of less than 0.5%.

[0018] Preferred high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 25%~30% and a water reduction rate of 30%~35%. Purchased from Xuzhou Zhujian Building Materials Technology Co., Ltd., the addition of polycarboxylate-based high-performance water-reducing agent can significantly reduce the porosity of hardened concrete, making the concrete denser, reducing the heat of hydration, and thus reducing water consumption; it can also significantly improve the concrete's resistance to freeze-thaw cycles, impermeability, and sulfate attack, comprehensively improving the physical properties of the concrete.

[0019] The second objective of this invention is to provide a method for preparing low-carbon, high-strength, corrosion-resistant pipe piles, which eliminates the impact of high-pressure steam curing on the durability of concrete by eliminating the need for pressure steam curing during the molding process.

[0020] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: first static rest time of 3 hours, then heating rate of 25℃ / h, constant temperature of 85℃ for 4 hours, and cooling rate of 25℃ / h.

[0021] In summary, the present invention has the following beneficial effects: This invention proposes a low-carbon, high-strength, corrosion-resistant pipe pile. The concrete mix of the pile body incorporates composite admixtures, resulting in high concrete density after centrifugal molding and reduced microstructural cracks. By compounding corrosion inhibitors, which act as a surfactant in the concrete, the admixtures, through their unique surface chemistry and high specific surface area, adsorb and neutralize harmful chemicals, forming a protective layer to prevent corrosion. This improves the early strength of the concrete and enhances its resistance to chloride ion penetration and corrosion. Simultaneously, it effectively eliminates and inhibits the formation of large air bubbles, reducing the air bubble content in the concrete mixture, further decreasing the pore size, increasing density, and improving resistance to poor water quality. This enhances the concrete's electrical conductivity, resistance to chloride ion penetration, resistance to sulfate attack, frost resistance, impermeability, and corrosion resistance, effectively protecting the internal steel reinforcement from corrosion. It also improves the concrete's strength and workability, ensuring that the concrete does not separate or stratify after mixing, with aggregates such as sand and gravel evenly distributed, reducing internal and external quality issues caused by uneven concrete distribution.

[0022] (2) The low-carbon, high-strength, corrosion-resistant pipe pile proposed in this invention ensures the strength and durability of the concrete pipe pile while omitting the high-pressure steam curing process. The high-pressure steam curing-free process eliminates the impact of high-pressure steam curing on the durability of concrete. Only one curing process using atmospheric pressure steam is required to complete the production of the product, and it can meet the C100 grade concrete strength required by the standard. It significantly improves the impact resistance and ductility toughness of the pipe pile, reduces the brittleness of the pipe pile, and improves its performance. Compared with the prior art, the preparation method of the low-carbon, high-strength, corrosion-resistant pipe pile proposed in this invention can save more than 50% of natural gas energy; at the same time, it reduces the difficulty of work, reduces labor costs, and realizes the transformation of ordinary high-strength concrete to high-performance concrete, which is in line with the concept of ecological priority, green development, and high-quality development in the new era. At the same time, the silica fume and fly ash used are solid wastes generated in industrial production. Using them as admixtures in concrete makes them resource-based, which can reduce production costs to a certain extent and reduce environmental pollution. Detailed Implementation

[0023] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific implementation method, features and effects of a low-carbon, high-strength, corrosion-resistant pipe pile and its preparation method according to the present invention are described in detail below.

[0024] Sources of raw materials used in the examples:

[0025] Example 1

[0026] A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: 5.99 parts of composite admixture; 0.1 parts of corrosion inhibitor; 14.22 parts of cement; 26.74 parts of manufactured sand; 54.29 parts of crushed stone; 0.27 parts of high-performance water-reducing agent; and 4.49 parts of water.

[0027] The composite admixture is a mixture of ultrafine fly ash, silica fume and Class I fly ash in a ratio of 1.5:1:1.

[0028] The corrosion inhibitor comprises the following components in parts by weight: 40 parts of polydimethylsiloxane; 30 parts of 1-ethoxy-1-trimethoxycyclopropane; 30 parts of isostearyl isostearate.

[0029] The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 28% and a water reduction rate of 31%.

[0030] A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: first static rest time of 3 hours, then heating rate of 25℃ / h, constant temperature of 85℃ for 4 hours, and cooling rate of 25℃ / h.

[0031] Example 2

[0032] A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: 5.99 parts of composite admixture; 0.1 parts of corrosion inhibitor; 14.22 parts of cement; 26.74 parts of manufactured sand; 54.29 parts of crushed stone; 0.27 parts of high-performance water-reducing agent; and 4.49 parts of water.

[0033] The composite admixture is a mixture of ultrafine fly ash, silica fume and Class I fly ash in a ratio of 1.5:1:1.

[0034] The corrosion inhibitor comprises the following components in parts by weight: 30 parts of aminopropyl silicone oil; 30 parts of 1-ethoxy-1-trimethoxycyclopropane; 20 parts of 3-hydroxy-N-(2-methoxyphenyl)-2-naphthoamide.

[0035] The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 28% and a water reduction rate of 31%.

[0036] A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: first static rest time of 3 hours, then heating rate of 25℃ / h, constant temperature of 85℃ for 4 hours, and cooling rate of 25℃ / h.

[0037] Example 3

[0038] A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: 6.03 parts of composite admixture; 0.06 parts of corrosion inhibitor; 14.22 parts of cement; 26.74 parts of manufactured sand; 54.29 parts of crushed stone; 0.27 parts of high-performance water-reducing agent; and 4.49 parts of water.

[0039] The composite admixture is a mixture of ultrafine fly ash, silica fume and Class I fly ash in a ratio of 1.5:1:1.

[0040] The corrosion inhibitor comprises the following components in parts by weight: 35 parts of polydimethylsiloxane; 20 parts of 1-ethoxy-1-trimethoxycyclopropane; 10 parts of mono- and diglyceride fatty acid esters.

[0041] The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 28% and a water reduction rate of 31%.

[0042] A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: first static rest time of 3 hours, then heating rate of 25℃ / h, constant temperature of 85℃ for 4 hours, and cooling rate of 25℃ / h.

[0043] Example 4

[0044] A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: 6.03 parts of composite admixture; 0.06 parts of corrosion inhibitor; 14.22 parts of cement; 26.74 parts of manufactured sand; 54.29 parts of crushed stone; 0.27 parts of high-performance water-reducing agent; and 4.49 parts of water.

[0045] The composite admixture is a mixture of ultrafine fly ash, silica fume and Class I fly ash in a ratio of 1.5:1:1.

[0046] The corrosion inhibitor comprises the following components in parts by weight: 40 parts of aminopropyl silicone oil; 20 parts of 1-ethoxy-1-trimethoxycyclopropane; 10 parts of mono- and diglyceride fatty acid esters; and 10 parts of isostearyl isostearate.

[0047] The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 28% and a water reduction rate of 31%.

[0048] A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: first static rest time of 3 hours, then heating rate of 25℃ / h, constant temperature of 85℃ for 4 hours, and cooling rate of 25℃ / h.

[0049] Example 5

[0050] A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: 5.99 parts of composite admixture; 0.1 parts of corrosion inhibitor; 14.22 parts of cement; 26.74 parts of manufactured sand; 54.29 parts of crushed stone; 0.27 parts of high-performance water-reducing agent; and 4.49 parts of water.

[0051] The composite admixture is a mixture of ultrafine fly ash, silica fume and Class I fly ash in a ratio of 1.5:1:1.

[0052] The corrosion inhibitor comprises the following components in parts by weight: 20 parts of polydimethylsiloxane; 20 parts of aminopropyl silicone oil; 30 parts of 1-ethoxy-1-trimethoxycyclopropane; 10 parts of isostearyl isostearate.

[0053] The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 28% and a water reduction rate of 31%.

[0054] A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: first static rest time of 3 hours, then heating rate of 20℃ / h, constant temperature of 85℃ for 4 hours, and cooling rate of 25℃ / h.

[0055] Comparative Example 1 A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: The composition of the composite admixture is 5.99 parts; cement is 14.22 parts; manufactured sand is 26.74 parts; crushed stone is 54.29 parts; high-performance water-reducing agent is 0.27 parts; and water is 4.49 parts.

[0056] The composite admixture is a mixture of ultrafine fly ash, silica fume and Class I fly ash in a ratio of 1.5:1:1.

[0057] The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 28% and a water reduction rate of 31%.

[0058] A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: first static rest time of 3 hours, then heating rate of 25℃ / h, constant temperature of 85℃ for 4 hours, and cooling rate of 25℃ / h.

[0059] Comparative Example 2 A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: Corrosion inhibitor 0.1 parts; cement 20 parts; manufactured sand 26.74 parts; crushed stone 54.29 parts; high-performance water-reducing agent 0.27 parts; water 4.49 parts.

[0060] The corrosion inhibitor comprises the following components in parts by weight: 40 parts of polydimethylsiloxane; 30 parts of 1-ethoxy-1-trimethoxycyclopropane; 30 parts of isostearyl isostearate.

[0061] The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 28% and a water reduction rate of 31%.

[0062] A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: first static rest time of 3 hours, then heating rate of 25℃ / h, constant temperature of 85℃ for 4 hours, and cooling rate of 25℃ / h.

[0063] Comparative Example 3 A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: 5.99 parts of composite admixture; 1 part of corrosion inhibitor; 14.22 parts of cement; 26.74 parts of manufactured sand; 54.29 parts of crushed stone; 0.27 parts of high-performance water-reducing agent; 4.49 parts of water.

[0064] The composite admixture is a mixture of ultrafine fly ash, silica fume and Class I fly ash in a ratio of 1.5:1:1.

[0065] The corrosion inhibitor comprises the following components in parts by weight: 40 parts of polydimethylsiloxane; 30 parts of 1-ethoxy-1-trimethoxycyclopropane; 30 parts of isostearyl isostearate.

[0066] The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 28% and a water reduction rate of 31%.

[0067] A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: first static rest time of 3 hours, then heating rate of 25℃ / h, constant temperature of 85℃ for 4 hours, and cooling rate of 25℃ / h.

[0068] Comparative Example 4 A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: 5.99 parts of Grade I fly ash; 0.1 parts of corrosion inhibitor; 14.22 parts of cement; 26.74 parts of manufactured sand; 54.29 parts of crushed stone; 0.27 parts of high-performance water-reducing agent; 4.49 parts of water.

[0069] The corrosion inhibitor comprises the following components in parts by weight: 40 parts of polydimethylsiloxane; 30 parts of 1-ethoxy-1-trimethoxycyclopropane; 30 parts of isostearyl isostearate.

[0070] The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 28% and a water reduction rate of 31%.

[0071] A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: first static rest time of 3 hours, then heating rate of 25℃ / h, constant temperature of 85℃ for 4 hours, and cooling rate of 25℃ / h.

[0072] Comparative Example 5 A low-carbon, high-strength, corrosion-resistant pipe pile comprises the following components in parts by weight: 5.99 parts of composite admixture; 0.1 parts of corrosion inhibitor; 14.22 parts of cement; 26.74 parts of manufactured sand; 54.29 parts of crushed stone; 0.27 parts of high-performance water-reducing agent; and 4.49 parts of water.

[0073] The composite admixture is a mixture of ultrafine fly ash, silica fume and Class I fly ash in a ratio of 1.5:1:1.

[0074] The corrosion inhibitor comprises the following components in parts by weight: 40 parts of polydimethylsiloxane; 30 parts of 1-ethoxy-1-trimethoxycyclopropane; 30 parts of isostearyl isostearate.

[0075] The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content of 28% and a water reduction rate of 31%.

[0076] A method for preparing low-carbon, high-strength, corrosion-resistant pipe piles includes the following preparation steps: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing, a two-stage curing process is adopted, which involves first curing with atmospheric pressure steam and then with high pressure steam. The atmospheric pressure steam curing is carried out at 95℃, while the high pressure steam curing is carried out under pressure at 1.0MPa and 180℃.

[0077] Performance verification The molded specimens obtained in the examples and comparative examples were used to measure the compressive strength, electrical flux, and chloride ion migration coefficient of the concrete at steam curing demolding, 3 days, and 28 days. The results are as follows:

[0078] The results above show that the pipe piles prepared using the method of this invention, after being formed in a centrifuge, are steam-cured under normal pressure using a single steam curing regime: a 3-hour static curing period, a heating rate of 25℃ / h, a constant temperature of 85℃ for 4 hours, and a cooling rate of 25℃ / h. The compressive strength of the pipe piles at demolding, 3 days, and 28 days after steam curing is significantly higher than that of the comparative example. The composite admixture dosage is 5.99%, and the corrosion inhibitor dosage is 0.1%, reducing cement usage. This results in increased concrete strength, lower electrical flux, and lower chloride ion migration coefficient, indicating that the pipe piles exhibit good resistance to chloride ion penetration and corrosion.

[0079] Compared with Example 1, Comparative Example 1 did not add any corrosion inhibitors. It was found that the compressive strength at steam curing demolding, 3 days, and 28 days was reduced, while the electrical flux increased by 51C, and the chloride ion migration coefficient (m) was lower. 2 The 24.21% increase in / s indicates that the corrosion inhibitor reduces the surface tension of the liquid phase in the concrete mixture, destroys the original air bubbles, further reduces the total amount of air bubbles in the concrete mixture, reduces the pore size of the concrete, increases the compactness of the concrete, and gives the pipe pile better mechanical properties and corrosion resistance.

[0080] Compared with Example 1, Comparative Example 2 did not contain any composite admixtures and had an excessive cement content. It was found that the compressive strength at steam curing demolding, 3 days, and 28 days was reduced, while the electrical flux increased by 39C, and the chloride ion migration coefficient (m) was also lower. 2The efficiency of concrete pipe piles prepared by replacing cement with composite admixtures by 17.62% ( / s) indicates that the present invention achieves the goal of low carbon, high strength and corrosion resistance by preparing concrete pipe piles that meet the requirements of low carbon, high strength and corrosion resistance.

[0081] Compared with Example 1, Comparative Example 3 showed an excessive amount of corrosion inhibitor, resulting in decreased compressive strength at steam curing demolding, 3 days, and 28 days. Simultaneously, the electrical flux increased by 48°C, and the chloride ion migration coefficient (m) was also reduced. 2 / s) increased by 24.25%. Combined with Comparative Example 1, it can be seen that although corrosion inhibitors, as a compound surfactant, can be added to concrete to effectively eliminate and inhibit the formation of large air bubbles, excessive dosage can have the opposite effect. This invention ensures its performance advantages by controlling the dosage of components.

[0082] Compared with Example 1, Comparative Example 4 only used Grade I fly ash. It was found that the compressive strength at steam curing demolding, 3 days, and 28 days was reduced, while the electrical flux increased by 44C, and the chloride ion migration coefficient (m) was also lower. 2 The yield per unit volume ( / s) increased by 21.13%, indicating that the composite admixture formed after compounding in this invention has a continuously distributed particle size and the most compact packing. This results in good concrete density after centrifugal molding of pipe piles and reduces microstructural cracks.

[0083] Comparative Example 5, compared to Example 1, used both atmospheric pressure steam curing and high pressure steam curing. The data results show little difference in effect compared to this application, indicating that the high-pressure-free steam curing process used in this invention can achieve the C100 grade concrete strength required by the standard. This significantly improves the impact resistance and ductility of the pipe piles.

[0084] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A low-carbon high-strength corrosion-resistant pipe pile, characterized by, The components include the following parts by weight: 5.5 to 6.5 parts of composite admixture; Corrosion inhibitor 0.05~0.2 parts; 13-15 parts cement; 25-30 parts of manufactured sand; 50-55 parts crushed stone; 0.1~0.3 parts of high-performance water-reducing agent; 4-6 parts water; The corrosion inhibitor comprises the following components in parts by weight: 20-30 parts of antifoaming polymer; 10-20 parts of polymer material additives; 10-25 parts of stabilized adhesive; 15-25 parts preservative; The polymer material additive is 1-ethoxy-1-trimethoxycyclopropane.

2. The low-carbon, high-strength, corrosion-resistant pipe pile according to claim 1, characterized in that, The composite admixture includes ultrafine fly ash, silica fume, and Class I fly ash, and the mixing ratio of the ultrafine fly ash, silica fume, and Class I fly ash is 1~2:0.8~1:0.8~1.

3. The low-carbon, high-strength, corrosion-resistant pipe pile according to claim 1, characterized in that, The foam-suppressing polymer is one or more of polydimethylsiloxane and aminopropyl silicone oil.

4. The low-carbon, high-strength, corrosion-resistant pipe pile according to claim 1, characterized in that, The stable adhesive is one or more of isostearyl isostearate, mono- and diglyceride fatty acid esters, and 3-hydroxy-N-(2-methoxyphenyl)-2-naphthoamide.

5. A low-carbon, high-strength, corrosion-resistant pipe pile according to claim 1, characterized in that, The preservative is multi-walled carbon nanotubes.

6. The low-carbon, high-strength, corrosion-resistant pipe pile according to claim 1, characterized in that, The manufactured sand is a mixture of coarse-grained sand, medium-grained sand and fine-grained sand in a weight ratio of 2~3:4~5:2~3. The coarse-grained sand has a particle size of 1.18-0.6mm; the medium-grained sand has a particle size of 0.6-0.3mm; and the fine-grained sand has a particle size of 0.3-0.15mm.

7. The low-carbon, high-strength, corrosion-resistant pipe pile according to claim 1, characterized in that, The high-performance water-reducing agent is a polycarboxylate-based high-performance water-reducing agent, with a solid content of 25% to 30% and a water reduction rate of 30% to 35%.

8. The method for preparing a low-carbon, high-strength, corrosion-resistant pipe pile according to claim 1, characterized in that, The preparation steps include the following: S01: Weigh each component raw material according to the mass ratio: S02: After the concrete specimens of the pipe piles are formed by centrifugal testing machine, they are steam cured according to the following single steam curing system: static rest time of 2~3h, then heating rate of 15~25℃ / h, constant temperature of 80~95℃ for 3~5h, and cooling rate of 25℃ / h.

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