Chlorine salt corrosion resistant prestressed concrete solid square pile and construction method thereof

Abstract

The invention discloses a chlorine salt corrosion resistant prestressed concrete solid square pile and a construction method thereof, a cementing material of a pile body concrete body of the square pile comprises a mineral admixture accounting for 50%-70% of the total mass of the cementing material, and the cementing material adopts Portland cement; sacrificial anode blocks electrically connected with the main reinforcements are embedded in the pile body concrete body. The pile body concrete body is doped with a composite corrosion-resistant and rust-resistant agent; the outer surface of the pile body concrete body is coated with polyurea waterproof paint or epoxy seal primer. An electromigration type corrosion inhibitor and a microcapsule containing bacillus are doped into the pile body concrete body; the prestressed main reinforcements are steel reinforcements with anti-corrosion coatings; and fiber bragg grating sensors are pre-embedded around the prestressed main reinforcements. The mixing proportion of the concrete body of the pile body is specially designed for fixing and blocking chloride ions, an inapplicable sulfate-resistant cement scheme is abandoned, and the chlorine salt resistance is improved from the source of materials.

Description

Technical Field

[0001] This invention relates to the field of civil engineering building materials and construction technology, specifically to a chloride-resistant prestressed concrete solid square pile and its construction method. Background Technology

[0002] In coastal areas, saline-alkali lands, or engineering environments using de-icing salt, the underground soil and water are rich in chloride ions. Chloride ions penetrate into the concrete, reach the surface of the reinforcing steel, and destroy its passivation film, leading to severe electrochemical corrosion of the steel. The corroded steel expands in volume, cracking the concrete protective layer and accelerating the corrosion process. Ultimately, this deteriorates the mechanical properties of the pile, severely impacting the safety and durability of the structure.

[0003] In existing technologies, measures to improve the corrosion resistance of concrete piles are mostly single methods, such as simply increasing the concrete density, adding mineral admixtures, or using sulfate-resistant cement. However:

[0004] 1. Lack of specificity: Sulfate-resistant cement mainly targets sulfate ions (SO4²⁻). - Corrosion, its component ratio is related to resistance to chloride ions (Cl) - Different corrosion requirements mean that using it alone will have limited effect.

[0005] 2. Systemic shortcomings: Focusing only on the material improvement of the pile itself, the treatment of the corrosive environment around the pile (especially the backfill area) is neglected. The interface between the pile body and the backfill sand / soil is often a weak point for the accumulation and liquefaction of corrosive media.

[0006] 3. Long-term reliability needs improvement: The lack of a systematic anti-corrosion solution, from materials and structure to the treatment of the surrounding environment, makes it difficult to ensure an ultra-long design service life in highly corrosive environments.

[0007] Therefore, there is an urgent need for a comprehensive solution for prestressed concrete solid square piles that controls the entire process from material formulation and pile structure to construction technology, specifically designed for chloride-corrosion environments. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a chloride-resistant prestressed concrete solid square pile. Through a systematic strategy combining "body corrosion protection" and "environmental isolation," it significantly improves the durability of the solid square pile in a chloride environment and eliminates the risk of liquefaction of the backfill sand around the pile. To achieve the above objectives, this invention is implemented through the following technical solution: This invention provides a chloride-resistant prestressed concrete solid square pile, comprising a pile body concrete, prestressed main reinforcement, and stirrups. The cementitious material of the pile body concrete contains mineral admixtures accounting for 50%-70% of the total mass of the cementitious material, and the cementitious material is silicate cement. The pile body has a sacrificial anode block that is electrically connected to the main reinforcement bar embedded inside the concrete body. The concrete body of the pile contains a composite anti-corrosion and rust-inhibiting agent; The outer surface of the concrete pile body is coated with polyurea waterproof coating or epoxy sealing primer. The pile body concrete contains an electromigration type rust inhibitor and microcapsules containing Bacillus subtilis. The prestressed main reinforcement is made of steel bars with anti-corrosion coating; The fiber optic grating sensor is pre-embedded around the prestressed main reinforcement.

[0009] Preferably, the mineral admixture is a mixture of two or three of mineral powder, fly ash, and silica fume, wherein the silica fume content accounts for 5%-10% of the total mass of the cementitious material.

[0010] Preferably, the composite corrosion inhibitor includes anodizing corrosion inhibitors and penetrating migration corrosion inhibitors.

[0011] Preferably, the anti-corrosion coating of the prestressed main reinforcement is an epoxy resin coating or a zinc plating layer.

[0012] The solid square pile provided by this invention has the following characteristics: 1. Strong targeted corrosion protection: The mix proportion of the pile concrete is specifically designed to fix and block chloride ions, abandoning the unsuitable sulfate-resistant cement scheme, and improving chloride resistance from the material itself.

[0013] 2. Multiple protections and high reliability: It forms a multi-layered, three-dimensional protection system consisting of "concrete + mineral admixtures + chemical rust inhibitors + steel reinforcement coating + sacrificial anode cathodic protection", which has a large safety margin and a long design service life.

[0014] This invention also provides a construction method for prestressed concrete solid square piles resistant to chloride salt corrosion, comprising the following steps: a. Carry out pile driving construction at the project site; b. After the pile driving is completed, grouting pipes are embedded in the backfill sand layer around the pile concrete body; c. Cement-based grout is injected under pressure into the backfill sand layer through the grouting pipe, so that the backfill sand layer is consolidated to form a low-permeability ring-shaped solidified barrier surrounding the pile body concrete.

[0015] Furthermore, the grouting pressure is 0.5MPa-1.5MPa.

[0016] Furthermore, the cement-based slurry is made of sulfoaluminate cement or a stabilized slurry containing an expansion agent.

[0017] Furthermore, the cement-based slurry incorporates an electromigration-type rust inhibitor and microcapsules containing Bacillus.

[0018] Furthermore, the cement-based grout uses sulfate-resistant silicate cement or ordinary silicate cement, with a water-cement ratio of 0.40-0.45, a chloride ion content of ≤0.10%, and an alkali content of ≤3kg / m³.

[0019] The construction method provided by this invention has the following characteristics: 1. Eliminate liquefaction risk: By using pile perimeter grouting technology, the easily liquefiable backfill sand is consolidated into a whole, which not only eliminates the hidden danger of foundation liquefaction, but also forms a solidified barrier that becomes an effective outer defense line against corrosion, achieving a perfect combination of earthquake resistance and corrosion prevention.

[0020] 2. Systematic Solution: By innovatively combining the improvement of the chloride salt corrosion resistance of square piles with construction methods, a complete chloride salt corrosion resistance solution is provided from the inside out and from the product to the environment, with significant comprehensive benefits.

[0021] 3. By combining "body corrosion prevention" with "environmental isolation", the durability of solid square piles in chloride salt environment is significantly improved, and the risk of liquefaction of backfill sand around the pile is eliminated. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the cross-sectional structure of the solid square pile of the present invention; Figure 2 This is a schematic diagram illustrating the effect of the pile perimeter grouting treatment according to the present invention.

[0023] The labels in the diagram are as follows: 1. Pile body concrete; 2. Prestressed main reinforcement (with coating); 3. Stirrups; 4. Concrete protective layer; 5. Sacrificial anode block; 6. Grouting pipe; 7. Backfill sand layer; 8. Annular solidified barrier formed after grouting. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Example 1 like Figures 1 to 2 As shown, this embodiment discloses a chloride-resistant prestressed concrete solid square pile, including a pile body concrete body 1, prestressed main reinforcement 2, and stirrups 3; the cementitious material of the pile body concrete body 1 contains mineral admixtures accounting for 50%-70% of the total mass of the cementitious material, and the cementitious material is silicate cement; a sacrificial anode block 5 electrically connected to the main reinforcement is pre-embedded inside the pile body concrete body 1; a composite anti-corrosion and rust-inhibiting agent is added to the pile body concrete body 1; the outer surface of the pile body concrete body 1 is coated with polyurea waterproof coating or epoxy sealing primer; an electromigration rust inhibitor and microcapsules containing Bacillus are added to the pile body concrete body 1; the prestressed main reinforcement 2 is steel bar with an anti-corrosion coating; and fiber optic grating sensors are pre-embedded around the prestressed main reinforcement 2.

[0026] The mineral admixture is a mixture of two or three of mineral powder, fly ash, and silica fume, with the silica fume content accounting for 5%-10% of the total mass of the cementitious material. Through the pozzolanic effect and micro-filling effect of the admixture, the porosity of the concrete is significantly reduced, the pore size is refined, and the chloride ion penetration channels are effectively blocked.

[0027] The concrete body of the pile body 1 explicitly excludes sulfate-resistant cement and uses ordinary Portland cement (Silicate cement). Its mineral composition (C3A content) can combine with chloride ions to form Friedel's salt, which to a certain extent fixes chloride ions and slows down their migration rate to the surface of the reinforcing steel. This design is the opposite of the approach of reducing C3A content in sulfate-resistant cement, and is a specific measure against chloride ion corrosion.

[0028] The composite corrosion inhibitor includes anodizing corrosion inhibitors (such as calcium nitrite) and penetrating migration corrosion inhibitors (MCI), forming a dual protection mechanism.

[0029] The anti-corrosion coating of the prestressed main reinforcement 2 is an epoxy resin coating or a zinc plating layer, which provides an additional physical barrier.

[0030] Sacrificial anode blocks 5 (such as zinc alloy anodes) are pre-embedded inside the concrete body 1 of the pile and connected to the prestressed main reinforcement 2 through conductive connectors. Once the protective layer is damaged and chloride ions invade, the sacrificial anode will corrode preferentially, thus providing cathodic protection for the prestressed main reinforcement 2.

[0031] Fiber Bragg grating (FBG) sensors are pre-embedded around the prestressed main reinforcement bar 2. These FBG sensors can monitor the strain and temperature changes of the reinforcement in real time, transforming "periodic inspection" into "real-time monitoring throughout the entire life cycle." This enables data-driven precision maintenance and life prediction, and is key to realizing "smart infrastructure." It also endows the pile foundation with "sensing" capabilities, enabling real-time monitoring and early warning of corrosion conditions.

[0032] The solid square pile provided in this embodiment has the following characteristics: 1. Strong targeted corrosion protection: The mix proportion of the pile body concrete is specifically designed to fix and block chloride ions, abandoning the unsuitable sulfate-resistant cement scheme, and improving the chloride resistance performance from the material itself.

[0033] 2. Multiple protections and high reliability: It forms a multi-layered, three-dimensional protection system consisting of "concrete + mineral admixtures + chemical rust inhibitors + steel reinforcement coating + sacrificial anode cathodic protection", which has a large safety margin and a long design service life.

[0034] Example 2 This embodiment provides a construction method for a solid square pile, wherein the solid square pile is the chloride-resistant prestressed concrete solid square pile of Embodiment 1. The construction method includes the following steps: a. Carry out pile driving construction at the project site; b. After the pile driving is completed, a grouting pipe 6 is installed in the backfill sand layer 7 around the pile concrete body 1; c. Cement-based grout is injected into the backfill sand layer 7 through the grouting pipe 6, so that the backfill sand layer 7 is consolidated to form a low-permeability ring-shaped solidified barrier 8 surrounding the pile body concrete 1.

[0035] Preferably, the grouting pressure is 0.5MPa-1.5MPa.

[0036] The cement-based grout is made of sulfoaluminate cement or a stabilized grout mixed with an expansion agent.

[0037] The cement-based slurry contains an electromigration-type rust inhibitor and microcapsules containing Bacillus.

[0038] The cement-based grout uses sulfate-resistant silicate cement or ordinary silicate cement, with a water-cement ratio of 0.40-0.45, chloride ion content ≤0.10%, and alkali content ≤3kg / m³.

[0039] The construction method provided in this embodiment has the following characteristics: 1. Eliminate liquefaction risk: By using pile perimeter grouting technology, the easily liquefied backfill sand is consolidated into a whole, which not only eliminates the hidden danger of foundation liquefaction, but also forms a solidified barrier 8 that becomes an effective outer defense line against corrosion, achieving a perfect combination of earthquake resistance and corrosion prevention.

[0040] 2. Systematic Solution: By innovatively combining the improvement of the chloride salt corrosion resistance of square piles with construction methods, a complete chloride salt corrosion resistance solution is provided from the inside out and from the product to the environment, with significant comprehensive benefits.

[0041] Example 3 Prestressed concrete solid square piles with a side length of 400 mm were fabricated. The solid square pile consists of a concrete pile body 1, prestressed main reinforcement 2, and stirrups 3. The concrete strength grade is C80.

[0042] Concrete mix proportions: P.O42.5 cement is used, and the total amount of cementitious materials is 500 kg / m³. Among them, mineral powder accounts for 30%, fly ash accounts for 20%, and silica fume accounts for 8% (total admixture 58%). The water-cement ratio is controlled at 0.29. The admixtures are polycarboxylate superplasticizer and composite rust inhibitor.

[0043] Structural measures: The concrete protective layer 4 is 45mm thick, the prestressed main reinforcement 2 is made of epoxy coated steel rod, and a zinc alloy sacrificial anode block 5 is pre-embedded every 2 meters inside the concrete body 1 of the pile body, and is connected to the main reinforcement cage (composed of prestressed main reinforcement 2 and stirrups 3) by galvanized steel wire.

[0044] Construction method: After pile driving, four grouting pipes 6 are symmetrically inserted around the pile. A grouting slurry mainly composed of sulfoaluminate cement with a water-cement ratio of 0.6 is prepared, and UEA expansion agent is added. Grouting is performed at a pressure of 0.8 MPa until grout appears on the ground around the pile. After 28 days of curing, core samples are taken from the consolidated body 8 around the pile for testing. Its impermeability grade reaches W8 or higher, and its relative density is greater than 0.8, completely eliminating the possibility of liquefaction.

[0045] This type of square pile and its construction method are particularly suitable for land reclamation projects in coastal tidal flat areas, and can effectively cope with harsh geological conditions such as high groundwater levels and abundant chloride ions.

[0046] Example 4 This embodiment provides a chloride-resistant prestressed concrete solid square pile, comprising a pile body concrete 1, prestressed main reinforcement 2, and stirrups 3, characterized in that: 1. Targeted concrete mix design: The technology employs dual or triple admixture of mineral admixtures. In cementitious materials, the total content of mineral admixtures (such as mineral powder, fly ash, and silica fume) accounts for 50%-70% of the total mass of the cementitious materials, with a recommended silica fume content of 5%-10%. Through the pozzolanic effect and micro-filling effect of the admixtures, the porosity of concrete is significantly reduced, the pore size is refined, and chloride ion penetration channels are effectively blocked.

[0047] Sulfate-resistant cement is explicitly excluded. Ordinary Portland cement (Silicate cement) is used, whose mineral composition (C3A content) can combine with chloride ions to form Friedel's salt, which to some extent fixes chloride ions and slows their migration to the surface of the reinforcing steel. This design is the opposite of the approach of sulfate-resistant cement, which reduces the C3A content, and is a specific measure against chloride ion corrosion.

[0048] The addition of composite corrosion inhibitors, including anodic corrosion inhibitors (such as calcium nitrite) and penetrating migration inhibitors (MCI), forms a dual protection mechanism.

[0049] 2. Structural corrosion protection enhancement: Increase the thickness of the concrete cover 4 outside the main reinforcement by more than 10% compared to the standard value.

[0050] The prestressed main reinforcement 2 uses epoxy resin coated steel bars or galvanized steel bars to provide additional physical barriers.

[0051] Sacrificial anode blocks 5 (such as zinc alloy anodes) are pre-embedded inside the concrete body 1 of the pile and connected to the main reinforcement through conductive connectors. Once the protective layer is damaged and chloride ions invade, the sacrificial anode will corrode preferentially, thus providing cathodic protection for the prestressed main reinforcement 2.

[0052] The key to the above-mentioned construction method for chloride-resistant prestressed concrete solid square piles lies in the post-pile driving treatment steps: After the pile driving is completed, grouting pipes 6 are buried in the backfill sand layer 7 around the pile.

[0053] A high-pressure grouting pump is used to inject chloride-resistant cement-based grout into the backfill sand layer 7. This grout can be made of sulfoaluminate cement or a stable grout containing a high proportion of mineral admixtures and expanding agents.

[0054] The grouting pressure is controlled at 0.5-1.5MPa to ensure that the grout fully penetrates and compacts the backfill sand, thus solidifying it into a whole.

[0055] After the grout solidifies, it forms a low-permeability ring-shaped solidified barrier 8. This barrier can effectively block the migration of external chloride ions and moisture into the pile body, and at the same time completely eliminate the risk of backfill sand liquefaction due to earthquakes and other reasons, realizing a leap from "treating the pile itself" to "treating the environment around the pile".

[0056] The following are engineering measures for preventing chloride corrosion in pile foundations: 1. Material selection and proportion optimization Concrete materials: In chloride-corrosion environments, the pile foundation concrete should use sulfate-resistant silicate cement or ordinary silicate cement (tricalcium aluminate content ≤5%), with a water-cement ratio controlled at 0.40-0.45, chloride ion content ≤0.10%, and alkali content ≤3kg / m³.

[0057] Corrosion inhibitors: When added to mineral admixtures (such as fly ash and mineral powder) and steel reinforcement rust inhibitors (non-nitrite), they can significantly reduce chloride ion permeability.

[0058] Increase the thickness of the protective layer: The thickness of the concrete protective layer 4 (concrete body outside the main reinforcement) of the prestressed pipe pile is ≥40mm, and the thickness of the concrete protective layer 4 (concrete body outside the main reinforcement) of the main reinforcement of the reinforced concrete cast-in-place pile is ≥55mm.

[0059] 2. Structural Design and Construction Technology Pile type selection: In highly corrosive environments, precast prestressed concrete pipe piles (PHC piles) or thick-walled pipe piles (wall thickness ≥ 95 mm) should be preferred, and cast-in-place piles should be avoided.

[0060] Joint treatment: Reduce the number of joints and set the joints in less corrosive soil layers; when welding the piles, the weld thickness should be ≥10mm and anti-corrosion sealant should be applied.

[0061] Pile protection: The impermeability grade of the concrete body 1 of the pile body is ≥P8 (moderate corrosion) or P10 (strong corrosion). The pile tip (lower end of the concrete body 1 of the pile body) adopts a closed type, and the pile top (top of the concrete body 1 of the pile body) is sealed with a steel plate (thickness ≥4mm).

[0062] 3. Special protective measures Surface coating: The outer surface of the concrete pile body 1 is coated with polyurea waterproof coating or epoxy sealing primer to enhance its resistance to chloride ion penetration.

[0063] Cathodic protection: Zinc alloy sacrificial anodes can be used for underwater pile foundations, with 4 sets of anodes evenly distributed for each pile.

[0064] Full core grouting treatment: C30 micro-expansion concrete or cement mortar is poured into the pipe pile to prevent groundwater from entering the pile cavity and corroding the steel bars.

[0065] 4. Construction and Acceptance Standards Construction control: Static pressure method is used for construction to avoid cracks caused by hammering; the quality of hole formation must be free of negative deviation to ensure that the thickness of the concrete cover meets the design requirements.

[0066] Acceptance testing: The anti-corrosion effect is verified by electric spark test (3000V), ultrasonic thickness gauge (coating thickness error ≤ ±10%) and concrete resistivity test (≥50kΩ·cm).

[0067] The main innovation of the construction method provided in this embodiment is: Innovation Point 1: From "Barrier Protection" to "Performance Reversal" and "Intelligent Sensing" These measures have changed the traditional approach of "delaying corrosion" and instead "actively inhibiting" or even "repairing" damage, giving the pile body the ability to sense itself.

[0068] 1. Electrochemical protection system (cathode protection / electromigration corrosion inhibition) Innovation: Applying electrochemical principles to pile foundations to achieve dynamic and proactive corrosion control.

[0069] Measure (1) Sacrificial Anode Method: Zinc alloy or magnesium alloy anode blocks are pre-embedded in the concrete of the pile body and electrically connected to the prestressed main reinforcement 2 through a conductor. In a corrosive environment, the anode blocks corrode preferentially (sacrifice), and the released current keeps the main reinforcement in a cathodic state, thereby completely inhibiting its corrosion. This is a "sacrifice the pawn to save the king" strategy.

[0070] Measure (2), Impressed Current Method: Install inert anodes in the pile body or pile cap, and continuously apply a small cathode current to the main reinforcement through an external power source. This method is suitable for projects with particularly harsh conditions or extremely long design life.

[0071] Measure (3) Electromigration type corrosion inhibitor (MCI): MCI is added to the concrete body 1 of the pile and the cement-based grout. When moisture penetrates, MCI molecules can spontaneously and directionally migrate to the surface of the steel reinforcement to form a monomolecular protective film, which is like "actively finding and repairing" the weak points of protection.

[0072] 2. Microbial-induced self-healing concrete (MICP) Innovation: The product of microbial metabolism automatically seals cracks and cuts off the channels for chloride ion invasion.

[0073] Solution: Microcapsules containing Bacillus subtilis are incorporated into the concrete during preparation. When microcracks develop later due to wet-dry cycles or loads and water intrudes, the microcapsules rupture, activating the bacteria and metabolizing them to produce calcium carbonate (calcite), which gradually heals the cracks.

[0074] Innovation: Transforming concrete piles from "static materials" into dynamic systems with "biological intelligence" to achieve self-repair of damage is a revolutionary breakthrough.

[0075] 3. Built-in fiber optic sensing and monitoring system Innovation: Giving the pile foundation "sensing" capabilities to achieve real-time monitoring and early warning of corrosion status.

[0076] Measures: Fiber optic grating (FBG) sensors are pre-embedded around the prestressed main reinforcement bar 2. The sensors can monitor the strain and temperature changes of the reinforcement bar in real time, and can sense the pH value or chloride ion concentration of the surrounding concrete through a special coating.

[0077] Innovation: Transforming "periodic inspection" into "real-time monitoring throughout the entire life cycle" enables data-driven precision maintenance and life prediction, which is key to realizing "intelligent infrastructure".

[0078] Innovation Point Two: Collaborative Design of Materials and Structures These measures achieve a synergistic protective effect of 1+1>2 by optimizing material combinations and structural construction.

[0079] 1. Design of graded functional concrete Innovation: The performance of concrete is customized according to the corrosion risk of different parts of the pile body to achieve optimal resource allocation.

[0080] Measures: Divide the pile body into different functional zones in terms of length and cross-section.

[0081] Enhanced splash zone / water level fluctuation zone: This area suffers the most severe chloride ion erosion, so ultra-high durability concrete, such as ultra-high performance concrete (UHPC) protective layer with a high proportion of silica fume, is used.

[0082] Standard zone of pile body: conventional high-performance concrete is used.

[0083] Innovation: It breaks the traditional concept of homogeneous pile materials, achieving both economy and efficiency by "using the best steel where it is needed most".

[0084] 2. Composite reinforcement materials and hybrid reinforcement systems Innovation: Replacing steel bars partially or completely with non-metallic materials to fundamentally solve the problem of steel bar corrosion.

[0085] Measure (1) FRP reinforcement (fiber reinforced composite reinforcement): Use carbon fiber (CFRP) or glass fiber (GFRP) reinforcement as all or part of the non-prestressed reinforcement. FRP reinforcement will never rust.

[0086] Measure (2) Mixed reinforcement: The core prestressing tendons still use high-strength steel strands (because their tensile properties are currently irreplaceable), but they are given the highest level of protection (such as epoxy coating + filler anti-corrosion grease); while the stirrups 3 and structural reinforcements are all made of FRP bars. This measure can prevent the stirrups 3 from rusting and breaking, which would cause the concrete cover 4 to peel off, thereby protecting the core prestressing tendons.

[0087] Innovation Point 3: Refined processing of key components and processes These measures significantly improve the reliability of traditional technologies by deepening and refining them.

[0088] 1. "Multiple sealing" structure in the end plate area Innovation: Focus on strengthening the weakest connection part of the pile body—the pile head.

[0089] Measures: At the joint between the end plate and the concrete, a composite sealant consisting of "high-performance sealant + water-swellable rubber strip + anti-corrosion coating" is used. The inner cavity of the end plate is filled with anti-corrosion grease or cement-based waterproof mortar to ensure complete isolation of the prestressed tendon ends from the external corrosive environment.

[0090] 2. Precision and quantitative design of high-performance concrete Innovation: Performance-based design (PBD) replaces traditional treatment-based design.

[0091] Measures: Instead of using a single concrete strength grade as the final goal, a limit value for the chloride ion diffusion coefficient is clearly defined as a design indicator. The cementitious material system (the optimal ratio of cement, mineral powder, fly ash, and silica fume) is optimized through computer models to ensure that the chloride ion concentration will not accumulate to a critical value on the surface of the reinforcing steel within the 100-year design life.

[0092] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features therein. These modifications or substitutions do not cause the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

Claims

1. A kind of anti-chlorine salt corrosion prestressed concrete solid square pile, including pile body concrete body (1), prestressed main reinforcement (2), stirrup (3), it is characterized in that: The cementing material of the pile body concrete body (1) includes 50%-70% of mineral admixture in total cementing material mass, and the cementing material uses Portland cement; The pile body concrete body (1) internally pre-buried is sacrificed anode block (5) electrically connected with main reinforcement (2); The pile body concrete body (1) is mixed with composite anticorrosive rust inhibitor; The outer surface of the pile body concrete body (1) is brushed polyurea waterproof paint or epoxy sealing primer; The pile body concrete body (1) is mixed with electromigration type rust inhibitor and microcapsule containing bacillus; The prestressed main reinforcement (2) uses steel bar with anticorrosive coating; The prestressed main reinforcement (2) is pre-buried around fiber Bragg grating sensor.

2. The anti-chloride-eroded prestressed concrete solid square pile according to claim 1, characterized in that: The mineral admixture is two or three kinds of compound in which the siliceous ash content accounts for 5%-10% of the total cementing material mass.

3. The anti-chloride-eroded prestressed concrete solid square pile according to claim 1, characterized in that: The composite anticorrosive rust inhibitor includes anode type rust inhibitor and penetration migration type rust inhibitor.

4. The anti-chloride-eroded prestressed concrete solid square pile according to claim 1, characterized in that: The anticorrosive coating of the prestressed main reinforcement (2) is epoxy resin coating or galvanized layer.

5. A construction method of the anti-chloride-eroded prestressed concrete solid square pile according to any one of claims 1 to 4, characterized in that, Including the following steps: a. In engineering site, carry out pile sinking construction; b. After pile sinking is completed, bury grouting pipe (6) in backfill sand layer (7) around the pile body concrete body (1); c. Through grouting pipe (6), pressure injection cement-based slurry into backfill sand layer (7), so that backfill sand layer is consolidated to form a low-permeability annular consolidated body barrier (8) surrounding the pile body concrete body (1).

6. The method of construction according to claim 5, wherein: The grouting pressure is 0.5MPa-1.5 MPa.

7. The method of construction according to claim 5, wherein: The cement-based slurry uses sulphoaluminate cement or stable slurry mixed with expansive agent.

8. The method of construction according to claim 5, wherein: The cement-based slurry is mixed with electromigration type rust inhibitor and microcapsule containing bacillus.

9. The method of construction according to claim 5, wherein: The cement-based slurry uses sulphate-resistant Portland cement or ordinary Portland cement, water-binder ratio is 0.40-0.45, chloride ion content ≤0.10%, alkali content ≤3kg / m³.

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