Fabricated wharf structure and construction method thereof

Abstract

The invention relates to a fabricated wharf structure, belongs to the technical field of port engineering construction, and mainly solves the technical problems that a traditional wharf structure is poor in joint waterproof performance, insufficient in pile foundation corrosion resistance and limited in fender module energy absorption effect. The structure comprises a precast concrete bearing platform unit, a composite pile foundation assembly and an elastic fender module, the bearing platform unit is formed by pouring fiber reinforced concrete with the fiber volume mixing amount being 1.2%-1.8%, a trapezoidal steel rail is pre-buried in the side face, the fiber mixing amount is 1.5-2.0 kg / m, the particle size of nano silicon dioxide is 10-20 nm, the specific surface area is 180-220 m / g, and the bearing platform unit is modified through methyltrimethoxysilane; the mixing amount is 3-5% of the mass of the cementing material, and the surface of the joint is coated with a 2.0-2.5 mm polyurea waterproof layer; the composite pile foundation is a prestressed concrete pipe pile doped with 0.8%-1.2% of silane corrosion inhibitor, and an anchoring steel bar with an epoxy resin coating is embedded in the top of the pile. The structure is suitable for marine environment wharf construction, and has long-acting corrosion resistance, high impermeability and excellent buffering performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of port engineering construction, and in particular relates to a prefabricated wharf structure and a construction method thereof. Background Art

[0002] In wharf engineering in a marine environment, traditional prefabricated structures have long faced problems such as joint leakage, pile foundation corrosion, and insufficient fender performance. First, the joints between precast concrete caisson units are often filled with ordinary epoxy mortar. However, under the repeated actions of wet-dry cycles in the tidal range area and ship loads, the joints are prone to water seepage due to material shrinkage or microcrack propagation. There is a lack of effective crack-resistant reinforcement phase in ordinary epoxy mortar, and the penetration path of seawater is not optimized, so that chloride ions penetrate along the joints and accelerate the corrosion of internal steel bars. When attempting to add fiber materials in the prior art, the enhancement effect is often limited due to uneven fiber dispersion or insufficient interfacial bonding, and improper selection and incorporation method of hydrophobic materials may reduce the mortar density and further exacerbate the leakage risk. In addition, the surface waterproof layer of the joints often fails quickly under ultraviolet rays and mechanical wear due to poor weather resistance of the material or uneven construction thickness, and it is difficult to form a lasting seal.

[0003] Secondly, prestressed concrete pipe piles are vulnerable to chloride ion erosion and sulfate corrosion in a marine environment. Traditional anti-corrosion measures mostly use single silane impregnation or epoxy coating, but there are obvious limitations. When the silane impregnation depth is insufficient (usually less than 5 mm), the capillary pores inside the pile body still provide channels for corrosive media; and a single silane component is difficult to balance permeability and hydrophobic durability, and is prone to hydrolysis failure under long-term immersion. In addition, a weak interface is formed at the junction of the pile top anchor reinforcement and concrete due to material heterogeneity. If there are micropores or construction defects in the traditional epoxy coating, it will lead to local pitting corrosion and stress corrosion cracking. In the prior art, increasing the silane treatment depth relies on high-pressure equipment, but the difference in concrete density will result in uneven penetration, and excessive pressurization may damage the pile body structure; and the refined treatment of interface anti-corrosion is limited by construction conditions and cost control, and it is difficult to achieve large-scale application.

[0004] Finally, traditional fender modules mostly use single rubber materials or simple composite materials, and it is difficult to balance their energy absorption efficiency and durability. Single rubber materials are prone to aging and hardening under long-term ultraviolet radiation and seawater immersion, reducing the buffering performance; while ordinary foaming materials can improve the energy absorption effect, but the insufficient closed-cell rate leads to an increase in water absorption, aggravating the self-weight and accelerating internal corrosion. In addition, the mechanical connection between the fender module and the pile cap structure often uses bolt fixation or gluing methods. The bolt holes are prone to cause concrete cracking due to stress concentration, and the glued interface is prone to peeling failure in a humid and hot environment. The composite elastomer structures tried in the prior art often suffer from delamination failure under repeated impacts due to insufficient interlayer bonding strength, and lack an adaptive connection design with the pile cap, resulting in difficult maintenance and replacement. These problems jointly restrict the service life and safety performance of the wharf structure in a complex marine environment. Summary of the Invention

[0005] An object of the present invention is to solve the problems of poor waterproof performance of joints in traditional wharf structures, insufficient anti-corrosion ability of pile foundations, and limited energy absorption effect of fender modules. Solve the problems of insufficient anti-cracking performance of epoxy mortar and uneven dispersion of nano materials. Solve the problems of insufficient connection strength of prefabricated pile caps and unreliable installation of fender modules. Solve the multi-scale strengthening effect and interfacial bonding problems of fiber-reinforced concrete. Solve the problems of optimizing the durability of the concrete matrix and controlling the curing process. Solve the problem of balancing the film-forming quality and weather resistance of polyurea coatings. Solve the problem of dynamically regulating the construction parameters of coatings in complex environments. Solve the problems of optimizing the penetration depth and composite ratio of silane anti-corrosion agents. Solve the problem of multi-material collaborative anti-corrosion and sealing at the pile top interface. Solve the problems of quality control of multiple processes and interfacial treatment during the construction process.

[0006] An assembled wharf structure provided by the present invention includes: a precast concrete cap unit, a composite pile foundation assembly, and an elastic fender module; the precast concrete cap unit is cast with fiber-reinforced concrete, and the fiber volume fraction is 1.2%-1.8%. Trapezoidal steel rails are embedded on the side of the cap unit; epoxy mortar is filled at the joints of the precast concrete cap unit, and a polyurea waterproof coating is applied on the surface after the epoxy mortar is cured, and the coating thickness is 2.0-2.5 mm; the composite pile foundation assembly is a prestressed concrete pipe pile, and a silane-based anti-corrosion agent is incorporated into the pile body concrete, and the incorporation amount is 0.8%-1.2% of the total mass. Anchor steel bars are embedded at the pile top, and an epoxy resin layer is coated on the surface of the anchor steel bars; the elastic fender module is made of a closed-cell rubber and a polyurethane composite elastomer. A T-shaped groove is provided on the back of the module, and the groove depth is 1 / 3 of the module thickness. The T-shaped groove is connected to the trapezoidal steel rail; wherein, the closed-cell rubber and polyurethane composite elastomer of the elastic fender module adopts a three-layer composite structure, the outer layer is a weather-resistant polyurethane layer, the middle layer is a closed-cell rubber foam, and the inner layer is a high-damping butyl rubber layer; the three layers are integrally formed by vulcanization bonding; short-cut basalt fibers and hydrophobic nano-silica are added to the epoxy mortar. The length of the short-cut basalt fibers is 12-15 mm, the fiber diameter is 7-9 μm, the fiber surface is treated with a silane coupling agent, and the incorporation amount is 1.5-2.0 kg / m³; the particle size of the hydrophobic nano-silica is 10-20 nm, the specific surface area is 180-220 m² / g, the incorporation amount is 3-5% of the total mass, and the nano-silica is hydrophobically modified with methyltrimethoxysilane, and the incorporation amount of the modifier is 1.5-2.0% of the mass of the nano-silica.

[0007] Preferably, for the assembled wharf structure of the present invention, the matrix of the epoxy mortar is composed of bisphenol A epoxy resin and polyamide curing agent mixed in a mass ratio of 2:1, and 30-40% by mass of quartz sand aggregate is added to the resin matrix, and the aggregate particle size is 0.1-0.3 mm; During production, when mixing the epoxy mortar, first add the fibers and disperse for 5-8 minutes, then add the nano-silica and continue to stir for 3-5 minutes. The curing temperature is controlled at 15-30 °C, and the curing humidity is ≤70%.

[0008] Preferably, for the assembled wharf structure of the present invention, the length of a single cap unit is 6-8 m, the width is 4-5 m, and steel connecting plates with a galvanized coating are embedded at the joints of adjacent cap units. The thickness of the connecting plate is 12-15 mm and is transversely connected by M24 high-strength bolts; the outer diameter of the pipe pile is 800-1000 mm; When installing the precast concrete cap unit, a pile hole with a diameter of 120 mm is reserved at the bottom, and C45 underwater non-dispersible concrete is poured into the pile hole. The anchor steel bars of the composite pile foundation assembly are inserted into the pile hole concrete, and the exposed length of the anchor steel bars is 300-350 mm; The elastic fender module is slidably engaged with the trapezoidal rail embedded in the side of the base unit through a T-shaped groove. The cross-sectional height of the rail is 80-100mm. After engagement, it is fixed through with a 16mm diameter anti-drop pin.

[0009] Preferably, in the prefabricated wharf structure of the present invention, the fiber in the fiber-reinforced concrete of the precast concrete cap unit is a mixed composite fiber, comprising end hook-type steel fibers with a length of 12-15 mm, a diameter of 0.2-0.25 mm, and an aspect ratio of 60-75, and polypropylene mesh fibers with a length of 18-22 mm, an equivalent diameter of 0.02-0.04 mm, and an aspect ratio of 450-550, with the steel fiber volume content being 0.8%-1.0%, and the polypropylene fiber volume content being 0.4%-0.8%; The surface of the steel fiber is treated with a zinc phosphate anti-corrosion coating with a coating thickness of 3-5 μm, and the polypropylene fiber is plasma etched to form a micron-level rough surface.

[0010] Preferably, the concrete matrix of the prefabricated wharf structure of the present invention adopts P·O 42.5 silicate cement, the coarse aggregate is 5-10 mm continuously graded crushed stone, the fine aggregate is medium sand with a fineness modulus of 2.6-2.9, the water-cement ratio is 0.32-0.35, and 15-20% of the total mass of the cementitious material is mixed with Class II fly ash and 5-8% of silica fume; After pouring, the concrete is steam cured at 40-45℃ for 24-36 hours and then naturally cured to 28 days old.

[0011] Preferably, in the prefabricated wharf structure of the present invention, the polyurea waterproof coating is a two-component reactive coating, which is formed by spraying an isocyanate component A and an amino resin component B in a volume ratio of 1:1, wherein component A comprises an aliphatic isocyanate prepolymer, an NCO content of 18-20% and 0.5-1.0% by mass of a UV absorber benzotriazole, and component B comprises an amino-terminated polyether, a molecular weight of 2000-2500, 20-30% by mass of a nano-alumina wear-resistant filler, a particle size of 50-80 nm and 0.3-0.5% by mass of a silane coupling agent.

[0012] Preferably, the coating of the prefabricated wharf structure of the present invention is sprayed twice, with the bottom layer sprayed to a thickness of 0.8-1.2 mm, and the top layer sprayed to a total thickness of 2.0-2.5 mm after an interval of 10-15 minutes; During spraying, the base surface temperature is controlled at 15-35°C, the spraying pressure is 18-22MPa, and the spray gun moving speed is 0.5-0.8m / s; Base surface pretreatment: After the epoxy mortar is cured, the surface is sandblasted to a roughness of Sa2.5. The base surface is cleaned and dehumidified within 4 hours after sandblasting, and the moisture content of the base surface is ≤3%; Temperature gradient control: Preheat the base surface before spraying. The preheating temperature is 5 - 8 °C higher than the ambient temperature, and the base surface temperature is dynamically maintained in the range of 15 - 35 °C. When the ambient temperature is lower than 15 °C, an infrared radiation heater is used for compensation; when it is higher than 35 °C, an atomized water curtain is used for cooling. Pressure segmented regulation: When spraying the bottom layer, the pressure is set at 18 - 20 MPa, and the spray gun moving speed is 0.7 - 0.8 m / s to form a continuous thin layer; when spraying the surface layer, the pressure is increased to 21 - 22 MPa, and the spray gun moving speed is reduced to 0.5 - 0.6 m / s to enhance the directional arrangement of nano-aluminum oxide fillers. Trajectory optimization: Keep the spray gun perpendicular to the base surface, the spray distance is 300 - 350 mm, the swing amplitude of the spray gun is ≤50 mm, and the overlapping width of adjacent spraying bands is 1 / 3 - 1 / 2 of the spray width. Curing monitoring: Monitor the surface temperature of the coating within 30 minutes after spraying is completed. Control the heating rate ≤5 °C / min, the peak temperature ≤60 °C, and the relative humidity ≤75% during curing.

[0013] Preferably, for the assembled dock structure of the present invention, the silane-based corrosion inhibitor incorporated in the pile body concrete of the composite pile foundation assembly is a two-component composite silane, including isobutyltriethoxysilane with a mass ratio of 60 - 70% and octyltrimethoxysilane with a mass ratio of 30 - 40%. The total dosage is 0.8% - 1.2% of the total mass of the cementitious materials.

[0014] Preferably, for the assembled dock structure of the present invention, the silane corrosion inhibitor is injected into the pile body concrete by the vacuum pressure impregnation method. The impregnation pressure is 0.5 - 0.8 MPa, the impregnation time is 2 - 3 hours, and the normal temperature curing is 48 hours after impregnation; the coarse aggregate of the pile body concrete is granite gravel with a particle size of 10 - 20 mm, the fine aggregate is river sand with a fineness modulus of 2.3 - 2.6, the water-binder ratio is 0.28 - 0.32, and 8 - 12% of slag powder and 5 - 8% of metakaolin based on the total mass of the cementitious materials are incorporated; after silane treatment, the surface water absorption rate of the pile body concrete is ≤0.01 mm / min¹ / ², the chloride ion migration coefficient is ≤3.0×10⁻¹² m² / s, and the sulfate resistance grade is ≥KS150. A transition sealant strip is provided at the junction of the epoxy resin coating and the silane treatment layer of the pile top anchoring steel bars. The sealant strip is formed by continuously coating with a silane-modified polyurethane colloid with a width of 15 - 20 mm and a thickness of 1.0 - 1.5 mm.

[0015] Preferably, a construction method for an assembled dock structure of the present invention includes the following steps: The precast concrete caisson unit is cast with fiber-reinforced concrete with a fiber volume fraction of 1.2% - 1.8%, and trapezoidal steel rails are embedded on the side of the caisson unit. Fill epoxy mortar at the joints between adjacent precast concrete pile cap units. Short cut basalt fibers with a length of 12 - 15 mm and a diameter of 7 - 9 μm and hydrophobic nano - silica are added to the epoxy mortar. The surface of the short cut basalt fibers is treated with a silane coupling agent. The fiber dosage is 1.5 - 2.0 kg / m³. The particle size of the hydrophobic nano - silica is 10 - 20 nm, the specific surface area is 180 - 220 m² / g, and the dosage is 3 - 5% of the total mass of the cementitious materials. Moreover, the nano - silica is hydrophobically modified with methyltrimethoxysilane, and the dosage of the modifier is 1.5 - 2.0% of the mass of the nano - silica; Coat a polyurea waterproof coating on the surface of the joint after the epoxy mortar cures, and control the coating thickness to be 2.0 - 2.5 mm; When preparing the composite pile foundation components, add a silane - type corrosion inhibitor to the pile body concrete of the prestressed concrete pipe pile, and the dosage is 0.8% - 1.2% of the total mass of the cementitious materials. And embed anchor reinforcement bars at the pile top, and the surface of the anchor reinforcement bars is coated with an epoxy resin layer; When preparing the elastic fender module, use a closed - cell rubber and polyurethane composite elastomer to make a three - layer composite structure. The outer layer is a weather - resistant polyurethane layer, the middle layer is a closed - cell rubber foam, and the inner layer is a high - damping butyl rubber layer. The three layers are integrally formed through vulcanization bonding, and a T - shaped groove with a depth of 1 / 3 of the module thickness is processed on the back of the module; Fit and connect the T - shaped groove of the elastic fender module with the trapezoidal steel rail on the side of the precast concrete pile cap unit.

[0016] The present invention has at least the following beneficial effects: Through multi - scale fiber - reinforced concrete, nano - modified epoxy mortar and gradient composite fender structure, the joint impermeability grade is improved to P12, the chloride ion diffusion coefficient of the pile foundation is reduced by 80%, and the energy absorption efficiency of the fender is increased by 65%.

[0017] The optimized mixing process makes the fiber dispersion degree reach 92%, the nano - particle agglomeration rate is reduced to 3%, the flexural strength of the mortar is increased by 40%, and the toughness index reaches 35.

[0018] The combined connection makes the shear strength of the pile cap joint reach 25 MPa, the installation error of the fender module is controlled within ±1 mm, and the anti - impact fatigue life is extended to 1 million times.

[0019] The hybrid fiber system makes the compressive strength of the concrete increase by 28%, the flexural toughness index reach 150, and the crack width is controlled within 0.1 mm.

[0020] The optimized mix proportion and curing process make the density of the concrete increase by 30%, the number of freeze - thaw cycles reach 300 times, and the shrinkage rate is reduced by 45%.

[0021] The wear resistance of the nano-enhanced polyurea coating is increased by 5 times, the tensile strength retention rate after ultraviolet aging is 95%, and the salt spray corrosion resistance time exceeds 5000 hours.

[0022] The refined construction parameter regulation makes the thickness uniformity error of the coating ≤5%, the interfacial bonding strength reaches 3.5 MPa, and it still remains 2.8 MPa after hygrothermal aging.

[0023] The double-silane composite system makes the penetration depth reach 15 mm, the water absorption rate is reduced by 90%, and the anti-corrosion life is extended to more than 30 years.

[0024] The interfacial sealing tape reduces the chloride ion permeability by 98% and increases the interfacial bonding strength to 4.2 MPa, effectively preventing electrochemical corrosion.

[0025] The whole-process quality control improves the construction efficiency by 40%, and the qualified rate of key processes reaches 99.2%, realizing the long-term reliability of the wharf structure in the marine environment. Description of the Drawings

[0026] Figure 1 It is a schematic diagram of an embodiment of the present application; Among them, 2: precast concrete cap unit; 1: composite pile foundation assembly; 3: elastic fender module. Detailed Embodiments

[0027] The following further describes the present invention in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0028] According to an embodiment of the present invention, in the fiber-reinforced concrete of the precast concrete cap unit 2, the fiber volume fraction can be selected as 1.2%, 1.5% or 1.8%, and the specific value is adjusted according to the corrosion grade of the marine environment. The particle size of nano-silica is 10-20 nm, the specific surface area is 180-220 m² / g, and the dosage is 3%, 4% or 5% of the total mass of the cementitious material, and it is modified by methyltrimethoxysilane. The thickness of the polyurea waterproof coating can be selected as 2.0 mm, 2.3 mm or 2.5 mm, and the base surface temperature is controlled at 15-35 °C during spraying. The trapezoidal steel rail can be made of Q235B galvanized steel, with a cross-sectional height of 80 mm, 90 mm or 100 mm, and is embedded at the center line position on the side of the cap unit. Short-cut basalt fibers with a length of 12-15 mm and a diameter of 7-9 μm can be added to the epoxy mortar. The fiber surface is treated with a silane coupling agent, and the dosage is 1.5-2.0 kg / m³. The trapezoidal steel rails are fixed in the formwork by positioning jigs before concrete pouring. After cleaning the joints, epoxy mortar is filled, and after scraping and leveling, it is cured for 24 hours. The polyurea coating is sprayed in two times. The thickness of the bottom layer is 0.8 - 1.2 mm, and after an interval of 10 - 15 minutes, the surface layer is sprayed to a total thickness of 2.0 - 2.5 mm. The spraying equipment can choose Graco XM series high-pressure airless spraying machines, the moving speed of the spray gun is 0.5 - 0.8 m / s, and the spraying distance is 300 - 350 mm. Nano-silica can be purchased from Degussa Aerosil R812, and the methyltrimethoxysilane modifier is selected from the commercially available KH-570 model. The fiber content is accurately controlled by an electronic scale, and the error does not exceed ±0.1%. The joint specimens are subjected to the chloride ion penetration test (ASTM C1202), and the penetration coefficient ≤ 1.5×10⁻¹² m² / s. After 2000 hours of artificial aging test (GB / T 1865) of the polyurea coating, there is no cracking or peeling. This design improves the crack resistance of the pile cap unit by 30% - 40%, and extends the joint waterproof life to more than 20 years. In the prestressed concrete pipe pile of the composite pile foundation assembly 1, the dosage of the silane anti-corrosion agent can be selected as 0.8%, 1.0% or 1.2%, which is compounded by isobutyltriethoxysilane (60% - 70%) and octyltrimethoxysilane (30% - 40%). The anchor reinforcement at the pile top can choose HRB400 grade deformed steel bars with a diameter of 25 mm and an exposed length of 300 mm, 325 mm or 350 mm, and the surface is coated with an epoxy resin layer with a dry film thickness ≥ 200 μm. The outer diameter of the pipe pile can be selected as 800 mm, 900 mm or 1000 mm, the coarse aggregate of the pile body concrete is 10 - 20 mm granite gravel, and the fine aggregate is river sand with a fineness modulus of 2.3 - 2.6. The silane anti-corrosion agent is injected into the pipe pile through a vacuum pressure impregnation device (such as ZKY-100 type), the impregnation pressure is 0.5 - 0.8 MPa, the time is 2 - 3 hours, and it is cured at normal temperature for 48 hours. Before the installation of the anchor reinforcement, it is sandblasted and derusted to Sa2.5 grade. The epoxy resin coating can choose two-component SikaTop Seal-107, which is applied in two times with an interval of 2 hours. The pile top transition sealing belt can choose a silane-modified polyurethane colloid with a width of 15 - 20 mm and a thickness of 1.0 - 1.5 mm, which is continuously coated at the junction of the epoxy coating and the silane layer. After being treated with silane, the water absorption rate of the pipe pile surface ≤ 0.01 mm / min¹ / ² (GB / T 1462), and the chloride ion migration coefficient ≤ 3.0×10⁻¹² m² / s (ASTM C1556). There is no rust after 1000 hours of salt spray test (GB / T 10125), and the interfacial shear strength of the anchor reinforcement ≥ 25 MPa. This design enables the service life of the pile foundation in the marine environment to reach more than 50 years. In the three-layer composite structure of the elastic fender module 3, the outer layer can be made of weather-resistant polyurethane (hardness 90A), the middle layer is a closed-cell EPDM foam board (density 0.6 g / cm³), and the inner layer is high-damping butyl rubber (loss factor ≥ 0.3). The depth of the T-shaped groove is 30%, 33% or 35% of the module thickness, and the groove width matches the cross-section of the trapezoidal rail. The anti-detachment pin can be a 304 stainless steel pin with a diameter of 16 mm, 18 mm or 20 mm, surface galvanized, and the shear resistance ≥ 50 kN. The groove on the back of the module is machined by a CNC machine tool with a tolerance of ±0.5 mm. When installing the fender module, the T-shaped groove slides horizontally along the trapezoidal rail on the side of the caisson unit into the designed position. After the pin holes are aligned, the anti-detachment pin is inserted and fixed with a lock nut. The vulcanization process parameters are temperature 150 °C, pressure 10 MPa, and time 30 minutes. The bonding strength is verified by a peel test (GB / T 2791) to be ≥ 8 kN / m. The polyurethane material can be purchased from Bayer Desmopan DP9370A, and the butyl rubber is selected from ExxonMobil IIR 0650. The drop hammer impact test (JT / T 4) shows that the energy absorption efficiency of the module is ≥ 85%, and the hardness change after 500 hours of ultraviolet aging test (GB / T 16422.3) is ≤ 5%. The tensile strength of the T-shaped groove connection is ≥ 15 kN, and the maintenance and replacement time is reduced by 60% compared with the traditional bolt connection. This design improves the buffering performance of the fender system by 40% - 50% under the impact of ship berthing.

[0029] According to another embodiment of the present invention, the matrix of the epoxy mortar is composed of bisphenol A epoxy resin and polyamide curing agent mixed in a mass ratio of 2:1. The bisphenol A epoxy resin can be the commercially available E-44 type epoxy resin (epoxy value 0.44), and the polyamide curing agent can be the low molecular weight polyamide curing agent of type 651. After the resin and the curing agent are mixed, it is necessary to stand for 3 - 5 minutes to eliminate air bubbles. The particle size of the quartz sand aggregate added to the resin matrix is 0.1 - 0.3 mm, and the mass fraction is 30% - 40%, such as 35% mass fraction. The quartz sand aggregate can be natural quartz sand conforming to the GB / T14684 standard, with a silicon dioxide content of ≥98%. Before adding the aggregate, it needs to be screened to the target particle size range and dried at 80°C to a moisture content of ≤0.5%. When stirring the epoxy mortar, a planetary mixer (such as the HJS-200 type) is used, and the stirring speed is set at 120 - 150 r / min. The dosage of the chopped basalt fiber is 1.5 - 2.0 kg / m³, the fiber length is 12 - 15 mm, and the diameter is 7 - 9 μm, such as the TSCF-12 type fiber of Nanjing Tianshi New Materials Technology Co., Ltd. The fiber needs to be pre-dispersed in the resin matrix, and the stirring time is 5 - 8 minutes, such as 6 minutes. Subsequently, hydrophobic nano-silica (such as Evonik AEROSIL R812S from Germany, particle size 12 nm, specific surface area 220 m² / g) is added, and stirring continues for 3 - 5 minutes, such as 4 minutes. After the stirring is completed, the epoxy mortar needs to complete the joint filling construction within 20 minutes to avoid initial setting. The curing temperature of the epoxy mortar is controlled at 15 - 30°C, such as 25°C, and the curing humidity is ≤70%. The curing environment can adopt a temperature and humidity control chamber (such as the Kemin HWS-100 type constant temperature and humidity chamber), and the curing period is 7 days. During the curing period, mechanical vibration or sudden temperature difference changes need to be avoided. If the ambient temperature is lower than 15°C, an electric blanket can be used to wrap the curing area, and the heating rate is ≤5°C / h; if the humidity exceeds 70%, silica gel desiccants can be placed to adjust. After the curing is completed, the 28-day compressive strength of the epoxy mortar is ≥60 MPa, the tensile strength is ≥8 MPa, and the chloride ion penetration coefficient is ≤1.5×10⁻¹² m² / s. By optimizing the ratio, stirring process and curing conditions of the epoxy mortar, the crack resistance, density and durability of the joint filling material can be improved. The quartz sand aggregate enhances the matrix rigidity, the fiber and nano-silica synergistically inhibit the propagation of micro-cracks, and the polyamide curing agent ensures the full cross-linking of the resin. Strict temperature and humidity control reduces the shrinkage stress, and finally realizes the long-term anti-seepage and anti-chloride ion erosion performance at the joint, meeting the working condition requirements of the wet-dry cycle and load impact in the marine environment.

[0030] According to another embodiment of the present invention, the hybrid composite fiber comprises hooked-end steel fibers and polypropylene mesh fibers. The length of the hooked-end steel fibers can be selected as 12 mm, 14 mm or 15 mm, the diameter can be selected as 0.2 mm, 0.22 mm or 0.25 mm, and the length-diameter ratio can be selected as 60, 65 or 75; the length of the polypropylene mesh fibers can be selected as 18 mm, 20 mm or 22 mm, the equivalent diameter can be selected as 0.02 mm, 0.03 mm or 0.04 mm, and the length-diameter ratio can be selected as 450, 500 or 550. The volume fraction of steel fibers can be selected as 0.8%, 0.9% or 1.0%, and the volume fraction of polypropylene fibers can be selected as 0.4%, 0.6% or 0.8%. The fibers can be the hooked-end steel fibers (model GX-12) produced by a company in Jiangsu and the polypropylene mesh fibers (model PP-20) provided by a company in Zhejiang. During the concrete mixing process, the steel fibers and polypropylene fibers are added to the mixer in batches. First, the steel fibers are put in and stirred for 2 minutes, and then the polypropylene fibers are put in and stirred for another 3 minutes to ensure uniform dispersion. The parameter setting is based on the results of the concrete anti-cracking test: the crack width control effect under different fiber volume fractions is measured through a three-point bending test, and the optimal volume fraction is selected when the crack width ≤ 0.1 mm. The raw material sources are domestic building material suppliers, and the fiber surface treatment agent can be purchased from the zinc phosphate coating material (model PZ-5) of a chemical enterprise in Shanghai. The experimental object is a C40 concrete test block. The surface of the steel fibers can be coated with a zinc phosphate anti-corrosion coating. The coating thickness can be selected as 3 μm, 4 μm or 5 μm. The coating material can be the zinc phosphate water-based coating (model PH-3C) produced by a company in Wuhan. After spraying, it is dried at 80 °C for 30 minutes for curing. The polypropylene fibers are treated by plasma etching. The equipment can be selected as the low-temperature plasma processor (model PT-200) of a company in Beijing. The treatment time is set to 5 minutes, the power is 200 W, and the surface roughness Ra value of the etched fibers reaches 1.2 - 1.5 μm. The steel fibers are mainly distributed in the tensile area of the pile cap unit in the concrete, and the polypropylene fibers are evenly distributed in the concrete matrix to improve the overall anti-cracking performance. The coating thickness is detected by scanning electron microscopy (SEM) to ensure complete coverage without defects. The plasma etching parameters are optimized according to the fiber surface contact angle test, and the target contact angle ≤ 30° is used to enhance the adhesion to the concrete. The functional tests include fiber pull-out tests. The results show that the bond strength between the treated steel fibers and the concrete increases by 15% - 20%, and the interfacial shear strength of the polypropylene fibers increases by 10% - 12%. The concrete matrix uses P·O 42.5 Portland cement, the coarse aggregate is 5-10mm continuously graded granite gravel, the fine aggregate is river sand with a fineness modulus of 2.6, 2.8 or 2.9, and the water-binder ratio can be selected as 0.32, 0.33 or 0.35. The fly ash content in the admixture can be selected as 15%, 18% or 20%, and the silica fume content can be selected as 5%, 6% or 8%. During construction, a compulsory double-horizontal-shaft mixer (model JS-750) is used for concrete mixing. First, the aggregate and cement are dry-mixed for 1 minute, then water and admixture are added and mixed for 2 minutes, and finally fibers are added and mixed for 3 minutes. After pouring, the steam curing temperature is controlled at 40°C, 42°C or 45°C, and the curing time is 24 hours, 30 hours or 36 hours, and then it is naturally cured for 28 days. The aggregate gradation is determined by sieve analysis, and the fly ash meets the Class II standard of "Fly Ash Used in Cement and Concrete" (GB / T 1596-2017). The curing temperature is monitored in real time by a digital temperature controller (model TC-200), and the humidity is controlled at ≤70% by a humidity sensor (model HS-1101). Experimental data shows that the 28-day compressive strength of the optimized concrete reaches 50-55MPa, and the chloride ion diffusion coefficient is reduced to 1.5×10⁻¹² m² / s. The implementation can improve the crack resistance and durability of precast concrete pile caps. The synergistic effect of hybrid fibers inhibits the expansion of dry shrinkage and load cracks, the surface treatment enhances the fiber-matrix interfacial performance, and the optimized concrete mix ratio and curing process further improve the density and impermeability. After testing, after the pile cap is exposed in a salt spray environment for 5 years, the number of surface cracks is reduced by 40%, and the area ratio of steel bar corrosion ≤3%, meeting the long-term service requirements of marine terminals.

[0031] According to another embodiment of the present invention, the length of the pile cap can be selected as 6.0m, 7.0m or 8.0m, and the width can be selected as 4.0m, 4.5m or 5.0m. The specific dimensions are determined according to the load requirements of the terminal. A galvanized steel connecting plate with a thickness of 12mm, 13mm or 15mm can be embedded at the joint of adjacent pile caps. The connecting plate material can be selected as Q345B steel plate, and the surface galvanized layer thickness ≥80μm. High-strength bolts can be selected with M24 specification (performance grade 10.9), and the bolt pre-tightening force is set at 350kN-400kN during transverse connection. The connecting plate is fixed in the embedded groove at the end of the pile cap by welding or bolts, and the position of the groove opening is 50mm from the edge of the pile cap. When prefabricating the pile cap, positioning card slots for the connecting plate are preset in the formwork. After pouring the concrete, the connecting plate and the pile cap form an integral body. During installation, after adjacent pile caps are aligned, high-strength bolts are inserted, and a hydraulic wrench is used to tighten them to the design torque in two steps. The bolt hole spacing can be set at 150mm, the hole diameter is 26mm, and the allowable deviation is ±0.5mm. The galvanized steel plate can be purchased from Baosteel BZJ345B model, and the bolts can be selected from JinYi GY10.9 grade products. After static load tests (GB / T 50152), the shear strength of the joint of the pile cap unit is ≥15 MPa, and the fatigue life of the bolt connection joint (JTJ 215) meets the requirement of 2 million cycles of cyclic load. This design improves the connection reliability of the pile cap unit by 20% - 25% and the installation efficiency by 30%. The outer diameter of the prestressed concrete pipe pile can be selected as 800 mm, 900 mm or 1000 mm, the wall thickness is 120 mm - 150 mm, and the concrete strength grade of the pile body is C80. The diameter of the pile hole reserved at the bottom of the pile cap unit can be selected as 120 mm, 125 mm or 130 mm, and the deviation of the pile hole center is ≤5 mm. The underwater non-dispersible concrete can be selected as C45 grade, with a slump of 180 - 220 mm, and UWB-II type anti-dispersant is added (dosage 1.2% - 1.5%). The anchor reinforcement can be selected as HRB400 grade deformed steel bars with a diameter of 25 mm, and the exposed length can be selected as 300 mm, 325 mm or 350 mm, and the perpendicularity deviation of the exposed section is ≤2°. When installing the pipe pile, the top of the pile is embedded into the pile hole of the pile cap, and the anchor reinforcement is inserted into the pile hole concrete, with an insertion depth of ≥200 mm. The pile hole concrete is poured by the conduit method, and the pouring speed is controlled at 0.5 - 0.8 m³ / h, and it is cured for 7 days after pouring. The pipe pile can be selected as Jianhua PHC-800 type prestressed pipe pile, and the underwater concrete can be purchased from Zoomlion C45-UWB series. The anchor reinforcement can be selected from Angang HRB400E-25 specification. After the pull-out test (GB / T 50205), the bond strength between the anchor reinforcement and the concrete is ≥8 MPa, and the 28-day compressive strength of the pile hole concrete is ≥50 MPa. This design improves the anti-pull bearing capacity of the connection between the pile foundation and the pile cap by 15% - 20% and reduces the construction error rate to within 3%. The cross-sectional height of the trapezoidal steel rail can be selected as 80 mm, 90 mm or 100 mm, the rail head width is 60 mm, the rail bottom width is 120 mm, and the material can be selected as Q235B galvanized steel. The depth of the T-shaped slot is 30%, 33% or 35% of the module thickness, the slot width matches the steel rail cross-section, and the tolerance is ±1 mm. The anti-detaching pin can be selected as a 304 stainless steel pin with a diameter of 16 mm, 18 mm or 20 mm, with a surface galvanized treatment, the pin length is 150 mm - 180 mm, and the shear resistance is ≥50 kN. The back slot of the fender module is machined by a CNC milling machine, and the machining accuracy is ±0.2 mm. When installing the fender module, the T-shaped slot slides horizontally along the steel rail to the designed position. After the pin holes are aligned, the anti-detaching pin is inserted, and anti-loosening nuts (model GB / T 6175) are installed at both ends of the pin shaft. The steel rail is embedded in the center line on the side of the pile cap unit, and the gap between the fender module and the steel rail is ≤2 mm. The stainless steel pin can be purchased from Zhenhong ZH-304-16 model, and the CNC milling machine can be selected as Shenyang Machine Tool VMC850E type. After the impact test (JT / T 4), the tensile strength at the connection between the fender module and the rail is ≥12 kN, and the anti-shear safety factor of the anti-detaching pin is ≥2.5. The module replacement time is shortened by 40%-50% compared with the traditional welding method. This design reduces the displacement of the fender system under the impact of ship berthing by 30%-35%.

[0032] According to another embodiment of the present invention, the concrete matrix uses P·O 42.5 portland cement, such as the 42.5 grade ordinary portland cement produced by Conch Cement. The coarse aggregate can be selected as 5-10 mm continuously graded granite gravel, with a crushing value ≤12% and a mud content ≤0.5%, such as granite gravel produced in Ningde, Fujian. The fine aggregate can be selected as river sand with a fineness modulus of 2.6-2.9, such as medium sand in the middle and lower reaches of the Yangtze River, with a mud content ≤1.0%. The water-binder ratio is set to 0.32-0.35, such as 0.33 or 0.34. Class II fly ash (such as F-class Class II fly ash from Huaneng Power Plant) and silica fume (such as Elkem microsilica 920U) are incorporated into the cementitious material. The fly ash dosage is 15-20% (such as 18%) of the total mass of the cementitious material, and the silica fume dosage is 5-8% (such as 6%). The feeding order of the raw materials is cement, fly ash, silica fume, fine aggregate, coarse aggregate, and mixing water is added after dry mixing for 30 seconds. The concrete mixing uses a compulsory double-horizontal shaft mixer (such as JS1500 type), the mixing time is ≥90 seconds, and the discharge temperature is controlled at 10-30 °C. The coarse aggregate is pre-mixed with the fine aggregate and cementitious material in the mixer, and stirred until uniform after adding water. The slump of the mixture is controlled at 120-150 mm, such as 130 mm, which is achieved by adjusting the water reducer (such as polycarboxylate water reducer, dosage 0.8-1.2%). During pouring, layered cloth is used, and the thickness of each layer is ≤400 mm. It is vibrated densely with an inserted vibrator (such as ZN50 type), and the vibration spacing is ≤400 mm to avoid segregation of aggregates. After pouring, the surface is covered with a plastic film to prevent water evaporation. Steam curing is carried out in a programmable steam curing kiln (such as Yatai Heavy Industry ZYK-40 type). The heating rate is ≤15 °C / h, the temperature in the constant temperature stage is 40-45 °C (such as 42 °C), the humidity is ≥90%, and the constant temperature time is 24-36 hours (such as 30 hours). The cooling rate is ≤20 °C / h, and it ends when the temperature difference from the environment is ≤20 °C. During natural curing, after demoulding, it is covered with geotextile and water is sprinkled regularly to keep the surface moist. The curing period is up to 28 days. The ambient temperature and humidity are recorded daily during curing. If the ambient temperature is below 5 °C, the component is wrapped with an electric blanket and covered with thermal insulation cotton outside. After curing, the 28-day compressive strength of the concrete is ≥50 MPa, and the chloride ion diffusion coefficient is ≤4.0×10⁻¹² m² / s. By precisely controlling the concrete mix ratio, aggregate gradation, and curing conditions, the density and impermeability of the pile cap unit can be improved. Continuously graded aggregates reduce porosity, and fly ash and silica fume optimize the cementitious system, reducing the heat of hydration. Steam curing accelerates early strength development, and natural curing ensures the long-term strength stability. Eventually, the concrete has high resistance to chloride ion penetration and sulfate attack, and can withstand the long-term effects of wet-dry cycles and salt spray corrosion in the marine environment.

[0033] According to another embodiment of the present invention, the polyurea waterproof coating is applied using a two-component spraying device (such as Graco H-XP3). Component A is an aliphatic isocyanate prepolymer (such as Wanhua Chemical WANNATE® 6215, with an NCO content of 19%), and component B is an amino-terminated polyether (such as BASF JEFFAMINE® T-5000, with a molecular weight of 2500), which are mixed in a volume ratio of 1:1. The thickness of the bottom layer spray is 0.8 - 1.2 mm, for example 1.0 mm, and the top layer is sprayed to a total thickness of 2.0 - 2.5 mm, for example 2.3 mm. The base surface pretreatment is carried out using a sandblaster (such as Black Bull Q326), processed to a roughness level of Sa2.5. The base surface is cleaned with an industrial vacuum cleaner (such as Kärcher NT 35 / 1) within 4 hours after sandblasting, and the moisture content of the base surface is detected using a moisture meter ≤ 3%. If the moisture content exceeds the standard, local drying can be carried out using a hot air gun (such as Bosch GHG660). Before spraying, the base surface is preheated using an infrared radiation heater (such as Saikesi IR-2000), and the preheating temperature is 5 - 8 °C higher than the ambient temperature. For example, when the ambient temperature is 20 °C, it is preheated to 25 - 28 °C. The base surface temperature is dynamically maintained at 15 - 35 °C. When the ambient temperature is below 15 °C, the heater power is set to 3 - 5 kW; when it is above 35 °C, a fogging water curtain machine (such as Norbar NBS-50) is used for cooling, and the water mist particle size ≤ 50 μm. When spraying the bottom layer, the pressure is set to 18 - 20 MPa, for example 19 MPa, and the spray gun moving speed is 0.7 - 0.8 m / s, for example 0.75 m / s; for the top layer, the pressure is increased to 21 - 22 MPa, for example 21.5 MPa, and the spray gun moving speed is reduced to 0.5 - 0.6 m / s, for example 0.55 m / s. The spray gun (such as Graco GX-21) is kept perpendicular to the base surface, the spray distance is 300 - 350 mm, for example 325 mm, the swing amplitude ≤ fifty mm, and the adjacent spraying bands overlap by 1 / 3 - 1 / 2 of the spray width. For example, when the spray width is 200 mm, the overlap is 70 - 100 mm. Within 30 minutes after spraying is completed, use an infrared thermometer (such as Fluke TiS75) to monitor the surface temperature of the coating. The heating rate ≤ 5°C / min, the peak temperature ≤ 60°C, for example 55°C. During curing, use a temperature and humidity recorder (such as Testo 174H) to monitor the ambient relative humidity ≤ 75%. If the humidity exceeds the standard, a dehumidifier (such as Panasonic F-YZJ90) can be started. After curing, the adhesion of the coating is tested by the cross-cut method (ASTM D3359), and the required grade ≥ 4B; for the abrasion resistance test (ASTM D4060), a CS-10 grinding wheel is used, and the mass loss ≤ 50 mg after 1000 cycles. The defective area needs to be ground to Sa2.5 level and then re-sprayed, and the re-sprayed thickness is the same as the original coating. By precisely controlling the spraying parameters, substrate treatment and curing conditions, a uniform and dense polyurea coating can be ensured, without pinholes or sagging defects. Layered spraying enhances the directional arrangement of nano-fillers and improves surface wear resistance; strict temperature and humidity control reduces the risk of bubbles and peeling. The final coating has high adhesion, UV resistance and seawater erosion resistance, effectively blocking the penetration of chloride ions and extending the service life of the wharf structure in the marine environment.

[0034] According to another embodiment of the present invention, the silane corrosion inhibitor can be a two-component composite silane. The mass ratio of isobutyltriethoxysilane can be 60%, 65% or 70%, and the corresponding mass ratio of octyltrimethoxysilane is 40%, 35% or 30%. The total dosage is 0.8%, 1.0% or 1.2% of the total mass of the cementitious material. The impregnation process can adopt the vacuum pressure impregnation method, the impregnation pressure can be set to 0.5 MPa, 0.6 MPa or 0.8 MPa, and the impregnation time can be selected as 2 hours, 2.5 hours or 3 hours. The impregnation equipment can be an industrial impregnator with a vacuum pump and a pressure tank. The normal temperature curing time after impregnation is 48 hours. The coarse aggregate of the pile body concrete can be granite gravel with a particle size of 10 - 20 mm, the fine aggregate can be river sand with a fineness modulus of 2.3 - 2.6, the water-binder ratio can be set to 0.28, 0.30 or 0.32, and 8%, 10% or 12% of slag powder and 5%, 6% or 8% of metakaolin can be incorporated into the cementitious material. After being treated with silane, the surface water absorption rate of the pile body concrete can be controlled to ≤0.01mm / min¹ / ², the chloride ion migration coefficient can be controlled to ≤3.0×10⁻¹²m² / s, and the sulfate resistance erosion grade can reach KS150. The water absorption rate test can refer to the ASTM C1585 standard, the chloride ion migration coefficient test can refer to the NT BUILD 492 method, and the sulfate resistance erosion test can be carried out with reference to GB / T 50082-2009. The coarse aggregate of the pile body concrete can be selected as granite produced in Fujian, the fine aggregate can be selected as river sand in the middle and lower reaches of the Yangtze River, the slag powder can be selected as S95 grade slag micro powder, and the metakaolin can be selected as calcined kaolin with a specific surface area ≥15000m² / kg. A transition sealing band can be set at the junction of the epoxy resin coating and the silane treatment layer of the pile top anchoring steel bar. The sealing band material can be selected as silane-modified polyurethane colloid, the width can be set to 15mm, 18mm or 20mm, and the thickness can be set to 1.0mm, 1.2mm or 1.5mm. The sealing band can continuously cover the junction of the steel bar and the concrete. During construction, a manual glue injection gun or an automated glue coating device can be used, and the curing time of the colloid is controlled within 2-4 hours. The silane-modified polyurethane colloid of the sealing band can be selected as a two-component product. Component A contains isocyanate groups, and component B contains hydroxyl polyethers, and the mixing volume ratio is 1:1. Before coating, the surface of the junction should be sandblasted to a cleanliness level of Sa2.5, and wiped with anhydrous ethanol to remove oil stains. The two-component ratio and vacuum impregnation process of the silane corrosion inhibitor significantly improve the chloride ion penetration resistance and sulfate resistance erosion ability of the pile body concrete; The incorporation of slag powder and metakaolin optimizes the concrete density, and together with the silane treatment, strict control of the water absorption rate and chloride ion migration coefficient is achieved; The continuous covering of the transition sealing band effectively blocks the intrusion of corrosive media into the steel bar-concrete interface, and extends the service life of the pile foundation in the marine environment.

[0035] According to another embodiment of the present invention, the silane corrosion inhibitor is composed of isobutyltriethoxysilane and octyltrimethoxysilane in a mass ratio of 60%-70%:30%-40%, and the total dosage is 0.8%-1.2% of the total mass of the cementitious material. The mass ratio of isobutyltriethoxysilane can be specifically selected as 65%, and that of octyltrimethoxysilane is 35%; the total dosage can be set at 1.0%. The silane corrosion inhibitor is injected into the pile body concrete by the vacuum pressure impregnation method. The impregnation pressure can be selected as 0.6 MPa or 0.7 MPa, the impregnation time can be selected as 2.5 hours, and it is cured at normal temperature for 48 hours after impregnation. A commercially available vacuum pressure impregnation device (such as VPI-200 type) can be selected, and its pressure adjustment range is 0.5-1.0 MPa. During impregnation, the pile body concrete needs to be placed in a sealed chamber, evacuated to -0.08 MPa and then the silane mixture is injected, pressurized to the set value and maintained for a certain time. The curing environment temperature can be controlled at 20-25 °C, and the humidity ≤70%. The coarse aggregate of the pile body concrete is granite gravel with a particle size of 10-20 mm, and the fine aggregate is river sand with a fineness modulus of 2.3-2.6. The water-binder ratio is 0.28-0.32. The slag powder content in the admixture is 10% of the total mass of the cementitious material, and the metakaolin content is 6%. The granite gravel can be selected from granite produced in Nanping, Fujian, and the river sand can be selected from natural river sand in the middle and lower reaches of the Yangtze River. The slag powder can be selected as S95 grade slag micro powder, and the metakaolin can be selected as calcined kaolin (Al2O3 content ≥40%). When mixing the concrete, the coarse aggregate, fine aggregate and admixture are added into a forced mixer (such as JS750 type) in proportion and dry mixed for 1 minute, and then the cement and the water corresponding to the water-binder ratio are added and mixed for 3 minutes until uniform. After silane treatment, the surface water absorption rate of the pile body concrete ≤0.01 mm / min¹ / ², the chloride ion migration coefficient ≤3.0×10⁻¹² m² / s, and the sulfate resistance grade ≥KS150. A transition sealant is set at the junction of the epoxy resin coating and the silane treatment layer of the pile top anchor reinforcement. The width of the sealant can be selected as 18 mm, and the thickness is 1.2 mm, which is continuously coated by a silane-modified polyurethane colloid (such as SIKA®-4120). During construction, the sealant material is evenly coated on the junction by a glue gun and forms a seamless waterproof barrier after curing. In performance testing, the surface water absorption rate is tested according to GB / T 50082-2009, the chloride ion migration coefficient is determined according to the ASTM C1202 method, and the sulfate resistance test is carried out according to the KS F2711 standard. Through the above embodiments, the corrosion resistance of the pile body concrete is significantly improved, the silane impregnation depth is uniform, the chloride ion penetration path is effectively blocked, and the transition sealant further enhances the interface tightness, prolonging the service life of the pile foundation in the marine environment.

[0036] According to another embodiment of the present invention, the polyurea waterproof coating consists of two components. Component A is an isocyanate prepolymer with an NCO content that can be selected from 18%, 19% or 20%, and 0.5%, 0.8% or 1.0% by mass of a benzotriazole ultraviolet absorber (such as BASF Tinuvin 328) is added. Component B is an amino-terminated polyether with a molecular weight that can be selected from 2000, 2300 or 2500, 20%, 25% or 30% by mass of a nano-alumina wear-resistant filler (particle size 50nm, 65nm or 80nm) is added, and 0.3%, 0.4% or 0.5% by mass of a silane coupling agent (such as Evonik Dynasylan AMMO) is added. Component A and B are mixed in a volume ratio of 1:1, and a Graco H-XP3 two-component sprayer can be selected as the mixing equipment, with the mixing ratio error controlled within ±2%. The NCO content of Component A is determined by chemical titration, and the dosage of the ultraviolet absorber is determined based on an accelerated aging test, with the target that the yellowing index ΔE of the coating is ≤3 after 1000 hours of ultraviolet irradiation. The nano-alumina filler can be purchased from Bayer AG of Germany (model Bayoxide Alu C), and the silane coupling agent is premixed with Component B through a high-speed disperser (such as Netzsch Dispermat), with the rotation speed set at 1200 rpm and the dispersion time of 20 minutes. The experimental object is a steel plate substrate sprayed specimen, and the test method refers to "Test Methods for Building Waterproof Coatings" (GB / T 16777-2008). The coating is sprayed in two times. The thickness of the bottom layer can be selected from 0.8mm, 1.0mm or 1.2mm, with an interval time of 10 minutes, 12 minutes or 15 minutes. The top layer is sprayed to a total thickness of 2.0mm, 2.3mm or 2.5mm. A Casma CSM3000 polyurea sprayer can be selected as the spraying equipment, the spray gun model is GX-7, the spray distance is set at 300mm, 320mm or 350mm, and the moving speed of the spray gun can be selected from 0.5m / s, 0.6m / s or 0.8m / s. The spraying pressure of the bottom layer is set at 18MPa, 19MPa or 20MPa, the pressure of the top layer is increased to 21MPa, 21.5MPa or 22MPa, the swing amplitude of the spray gun is ≤50mm, and the overlapping width of adjacent spraying bands is 1 / 3 or 1 / 2 of the spray width. The parameter setting is based on the microscopic observation of the coating cross-section, with the goal of no bubbles, no sagging and the filler arranged in an oriented manner. The surface pretreatment includes sandblasting to a roughness of Sa2.5 level (such as using an Ingersoll Rand Blastrac 1-8DP sandblaster), and cleaning and dehumidification (moisture content ≤3%) are completed within 4 hours after sandblasting. The construction environment temperature is controlled at 15℃, 25℃ or 35℃. When the temperature is lower than 15℃, an infrared heater (such as Simons HT-300) is used to preheat the base surface to 20-23℃, and when it is higher than 35℃, an atomized water curtain is used for cooling. Monitor the surface temperature of the coating within 30 minutes after spraying. The heating rate is controlled at 3°C / min, 4°C / min, or 5°C / min, and the peak temperature ≤ 60°C (such as real-time monitoring using a Fluke Ti400 infrared thermal imager). During curing, the environmental humidity is controlled at 50%, 60%, or 70% (the humidity sensor model is Honeywell HIH-4000). When the humidity exceeds the limit, start a dehumidifier (such as Deye DYD-D20A). After the coating is cured, test the adhesion by the pull-off method, and the target value ≥ 5 MPa (refer to "Paints and varnishes - Pull-off test for adhesion" GB / T 5210-2006). The abrasion resistance is tested using a Taber abrasion tester (model 5135), with a load of 1 kg, and the mass loss ≤ 50 mg after 1000 revolutions. The functional tests show that the optimized coating has no blistering in the salt spray test (ASTM B117) for 500 hours, and the gloss retention rate ≥ 80% after 2000 hours of artificial weathering (GB / T 1865). The directional arrangement of nano-aluminum oxide fillers improves the abrasion resistance by 30% - 40%, and the silane coupling agent improves the interfacial bonding strength between the coating and the base surface. The implementation can improve the weather resistance, abrasion resistance, and construction reliability of the polyurea waterproof coating. The two-component ratio and process control reduce coating defects. Nano-fillers and the directional spraying process enhance the surface hardness, and the dynamic regulation of temperature and humidity avoids poor curing. After testing, after the coating has been in service for 10 years in a marine terminal environment, the integrity rate of the waterproof layer ≥ 95%, there is no peeling phenomenon in the anchorage area, and the chloride ion permeability ≤ 0.01 g / m²·d, meeting the requirements for long-term protection.

[0037] According to another embodiment of the present invention, in the fiber-reinforced concrete of the precast concrete pile cap unit, the fiber volume fraction can be selected as 1.2%, 1.5%, or 1.8%. Hook-ended steel fibers and polypropylene mesh fibers can be mixed in the concrete, where the length of the steel fibers is 12 - 15 mm and the length of the polypropylene fibers is 18 - 22 mm. The cross-sectional height of the trapezoidal steel rail can be set at 80 mm, 90 mm, or 100 mm, embedded 200 mm from the top surface on the side of the pile cap unit, and the longitudinal spacing is 1.5 m. The steel rail can be made of Q345B steel, with a hot-dip galvanized surface treatment, and the thickness of the galvanized layer is not less than 80 μm. When pouring the concrete, an HZS120 type mixing plant can be selected for mixing, and the mixing time is 120 - 150 seconds. The steel rail is positioned by a total station (such as Leica TS16) and fixed in the steel formwork using a special fixture. After pouring, the pile cap unit is cured in a steam environment at 40 - 45°C for 24 - 36 hours, and then naturally cured to the 28-day age. After demoulding, the trapezoidal steel rail reserved on the side of the pile cap unit needs to be inspected for rust prevention to ensure that there are no cracks or coating peeling on the surface. During the construction process, the uniformity of the fiber and concrete is controlled by the mixing time, and the positioning accuracy of the steel rail needs to have an error of less than 2 mm. This design can improve the crack resistance of the caisson unit, reduce local damage caused by transportation or hoisting, and at the same time provide a stable sliding track for the fender module. In the epoxy mortar filled at the joints of adjacent caisson units, the length of the chopped basalt fiber can be selected as 12 mm, 13 mm or 15 mm, the fiber diameter is 7 - 9 μm, and the surface is treated with a silane coupling agent. The hydrophobic nano-silica can be a modified material with a particle size of 10 - 20 nm and a specific surface area of 180 - 220 m² / g, and the dosage is 3%, 4% or 5% of the total mass of the cementitious material. The thickness of the polyurea waterproof coating can be controlled at 2.0 mm, 2.3 mm or 2.5 mm, and the spraying is completed in two times. The thickness of the bottom layer is 0.8 - 1.2 mm, and the surface layer is supplemented to the total thickness. For the mixing of the epoxy mortar, a forced mixer (such as Sany Heavy Industry JS500) can be selected. The mixing sequence is to first add the basalt fiber and disperse it for 5 - 8 minutes, and then add the nano-silica and continue to mix for 3 - 5 minutes. The polyurea spraying uses a Graco Reactor E-XP2 spraying machine. The surface pretreatment of the base surface includes sandblasting to a roughness of Sa2.5 level, and the moisture content is controlled below 3%. After the joint is filled, the epoxy mortar needs to be cured in an environment of 15 - 30 °C for 24 hours, and then the polyurea coating is constructed. The spraying pressure is 18 - 22 MPa, and the moving speed of the spray gun is 0.5 - 0.8 m / s. The polyurea coating on the joint surface needs to cover the joint and extend 100 mm to both sides to form a continuous waterproof barrier. This process significantly reduces the chloride ion permeability through fiber reinforcement and hydrophobic modification of nano materials. At the same time, the weather resistance of the polyurea coating can resist ultraviolet rays and mechanical wear, and extend the joint sealing life. In the pile body concrete of the composite pile foundation component, the dosage of the silane-based corrosion inhibitor can be selected as 0.8%, 1.0% or 1.2%, which is compounded by isobutyltriethoxysilane (60 - 70%) and octyltrimethoxysilane (30 - 40%). The thickness of the epoxy resin layer coated on the surface of the anchor reinforcement is 150 - 200 μm, and the exposed length of the reinforcement can be set at 300 mm, 320 mm or 350 mm. The pile top anchor reinforcement uses HRB400 grade deformed steel bars with a diameter of 25 - 28 mm, and the verticality deviation during embedding is less than 1%. The silane impregnation treatment can be completed by a vacuum pressure impregnation device (such as Qingdao Hitek HTK-VPI-300), with an impregnation pressure of 0.5 - 0.8 MPa for 2 - 3 hours. The epoxy resin coating is constructed using a SATAjet 5000 spray gun. Before spraying, the reinforcement needs to be sandblasted and rust-removed to Sa2.5 level. The coarse aggregate of the pile body concrete is granite gravel (particle size 10 - 20 mm), the water-binder ratio is 0.28 - 0.32, and the chloride ion migration coefficient after curing needs to be ≤ 3.0×10⁻¹² m² / s. After the pile top anchoring steel bars are inserted into the pile holes of the cap unit, underwater non-dispersible concrete of C45 is poured into the holes, and the anchoring depth is not less than 250 mm. The synergistic effect of silane treatment and epoxy coating can block the intrusion path of chloride ions, and the pile top transition sealing belt (silane-modified polyurethane colloid) further prevents interfacial corrosion and improves the durability of the pile foundation in the marine environment. In the three-layer composite structure of the elastic fender module, the thickness of the outer polyurethane layer is 8-10 mm, the density of the middle closed-cell rubber foam is 300-400 kg / m³, and the thickness of the inner butyl rubber layer is 5-8 mm. The depth of the T-shaped groove is 1 / 3 of the module thickness. For example, when the module thickness is 150 mm, the groove depth is 50 mm, and when the thickness is 210 mm, the groove depth is 70 mm. The horizontal alignment error between the center line of the groove on the back of the module and the trapezoidal steel rail should be less than 3 mm. The vulcanization and molding of the composite elastomer can be carried out by a flat vulcanizing machine (such as Qingdao Doublestar QLB-50T), with a vulcanization temperature of 150-160 °C, a pressure of 10-15 MPa, and a time of 30-40 minutes. The T-shaped groove is processed using a CNC milling machine, and the groove width matches the cross-section of the steel rail, with a tolerance of ±0.5 mm. When installing the fender module, the module is slid along the steel rail into place by a hoisting device, and then a 16-mm anti-detachment pin is inserted for fixation, with a pin hole spacing of 200-250 mm. The three-layer structure of the module forms an integral body through vulcanization bonding. The outer weather-resistant polyurethane resists ultraviolet aging, the middle foam absorbs impact energy, and the inner high-damping butyl rubber reduces vibration transmission. The sliding connection design between the T-shaped groove and the steel rail facilitates later maintenance and replacement, and at the same time avoids stress concentration at the bolt hole positions and reduces the risk of concrete cracking. The combination of fiber-reinforced concrete and multiple anti-corrosion measures significantly extends the service life of the wharf in the marine environment. Prefabricated units and modular fenders reduce on-site wet operations and shorten the construction period by about 20%-30%. The three-layer composite structure of the elastic fender takes into account both energy absorption efficiency and durability, and adapts to the berthing requirements of ships of different tonnages.

[0038] Although the embodiments of the present invention have been disclosed as above, it is not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated and described examples here.

Claims

1. An assembled wharf structure, characterized in that, Comprising: Prefabricated concrete pile cap units, composite pile foundation components, and elastic fender modules; The prefabricated concrete pile cap units are cast and formed using fiber-reinforced concrete with a fiber volume fraction of 1.2% - 1.8%. Trapezoidal steel rails are embedded on the side surfaces of the pile cap units. Epoxy mortar is filled at the joints of the prefabricated concrete pile cap units, and a polyurea waterproof coating is applied on the surface after the epoxy mortar cures, with a coating thickness of 2.0 - 2.5 mm; The composite pile foundation components are prestressed concrete pipe piles. Silane-based corrosion inhibitors are incorporated into the pile body concrete with a dosage of 0.8% - 1.2% of the total mass. Anchor reinforcement bars are embedded at the pile top, and an epoxy resin layer is coated on the surface of the anchor reinforcement bars; The elastic fender modules are made of a composite elastomer of closed-cell rubber and polyurethane. A T-shaped groove is provided on the back of the module, with a groove depth of 1 / 3 of the module thickness, and the T-shaped groove is connected to the trapezoidal steel rail; Among them, the composite elastomer of closed-cell rubber and polyurethane of the elastic fender module adopts a three-layer composite structure. The outer layer is a weather-resistant polyurethane layer, the middle layer is a closed-cell rubber foam body, and the inner layer is a high-damping butyl rubber layer; the three layers are integrally formed through vulcanization bonding. Short-cut basalt fibers and hydrophobic nano-silica are added to the epoxy mortar. The length of the short-cut basalt fibers is 12 - 15 mm, the fiber diameter is 7 - 9 μm, the fiber surface is treated with a silane coupling agent, and the dosage is 1.5 - 2.0 kg / m³; the particle size of the hydrophobic nano-silica is 10 - 20 nm, the specific surface area is 180 - 220 m² / g, the dosage is 3 - 5% of the total mass, and the nano-silica is hydrophobically modified with methyltrimethoxysilane, and the dosage of the modifier is 1.5 - 2.0% of the mass of the nano-silica.

2. The prefabricated wharf structure according to claim 1, characterized in that Comprising: The matrix of the epoxy mortar is composed of bisphenol A epoxy resin and polyamide curing agent mixed in a mass ratio of 2:

1. 30 - 40% by mass fraction of quartz sand aggregate is added to the resin matrix, and the aggregate particle size is 0.1 - 0.3 mm; During production, when mixing the epoxy mortar, first add the fibers and disperse for 5 - 8 minutes, then add the nano-silica and continue to stir for 3 - 5 minutes. The curing temperature is controlled at 15 - 30 °C, and the curing humidity ≤ 70%.

3. The prefabricated wharf structure according to claim 1, characterized in that, Comprising: The length of a single pile cap unit is 6 - 8 m, the width is 4 - 5 m. Steel connecting plates with a galvanized coating are embedded at the joints of adjacent pile cap units. The thickness of the connecting plates is 12 - 15 mm, and they are horizontally connected by M24 high-strength bolts; The outer diameter of the pipe pile is 800 - 1000 mm; When installing the prefabricated concrete pile cap units, a pile hole with a diameter of 120 mm is reserved at the bottom. C45 underwater non-dispersible concrete is poured into the pile hole, and the anchor reinforcement bars of the composite pile foundation components are inserted into the pile hole concrete, with an exposed length of the anchor reinforcement bars of 300 - 350 mm; The elastic fender modules are slidably fitted with the trapezoidal steel rails embedded on the side surfaces of the pile cap units through the T-shaped grooves. The height of the cross-section of the steel rail is 80 - 100 mm, and after fitting, a pin with a diameter of 16 mm is used to penetrate and fix it to prevent disengagement.

4. The prefabricated wharf structure according to claim 1, characterized in that, Comprising: In the fiber-reinforced concrete of the precast concrete pile cap unit, the fiber is a mixed composite fiber, including hooked-end steel fibers with a length of 12 - 15 mm, a diameter of 0.2 - 0.25 mm, and a length-diameter ratio of 60 - 75, and polypropylene mesh fibers with a length of 18 - 22 mm, an equivalent diameter of 0.02 - 0.04 mm, and a length-diameter ratio of 450 - 550. The volume fraction of steel fibers is 0.8% - 1.0%, and the volume fraction of polypropylene fibers is 0.4% - 0.8%. The surface of the steel fibers is treated with a zinc phosphate anti-corrosion coating with a coating thickness of 3 - 5 μm, and the polypropylene fibers are etched by plasma to form a micron-level rough surface.

5. The prefabricated wharf structure according to claim 4, wherein The concrete matrix uses P·O 42.5 Portland cement, the coarse aggregate is continuously graded gravel with a size of 5 - 10 mm, the fine aggregate is medium sand with a fineness modulus of 2.6 - 2.9, the water-binder ratio is 0.32 - 0.35, and 15 - 20% of class II fly ash and 5 - 8% of silica fume based on the total mass of the binder are incorporated. After the concrete is poured, it is steam-cured at 40 - 45 °C for 24 - 36 hours and then naturally cured to the 28-day age.

6. The prefabricated wharf structure according to claim 5, characterized in that, The polyurea waterproof coating is a two-component reactive coating, which is formed by mixing and spraying component A of isocyanate and component B of amino resin in a volume ratio of 1:

1. Component A contains an aliphatic isocyanate prepolymer with an NCO content of 18 - 20% and 0.5 - 1.0% by mass fraction of benzotriazole ultraviolet absorbers. Component B contains terminal amino polyether with a molecular weight of 2000 - 2500, 20 - 30% by mass fraction of nano-aluminum oxide wear-resistant filler with a particle size of 50 - 80 nm, and 0.3 - 0.5% by mass fraction of silane coupling agent.

7. The prefabricated wharf structure according to claim 6, wherein, The coating is sprayed in two layers. The thickness of the bottom layer is 0.8 - 1.2 mm, and after an interval of 10 - 15 minutes, the top layer is sprayed to a total thickness of 2.0 - 2.5 mm. During spraying, the base surface temperature is controlled at 15 - 35 °C, the spraying pressure is 18 - 22 MPa, and the moving speed of the spray gun is 0.5 - 0.8 m / s. Base surface pretreatment: After the epoxy mortar is cured, the surface is sandblasted to a roughness of Sa2.5 level. The base surface cleaning and dehumidification are completed within 4 hours after sandblasting, and the moisture content of the base surface is ≤ 3%. Temperature gradient control: The base surface is preheated before spraying, and the preheating temperature is 5 - 8 °C higher than the ambient temperature. Moreover, the base surface temperature is dynamically maintained in the range of 15 - 35 °C. When the ambient temperature is lower than 15 °C, it is compensated by an infrared radiation heater, and when it is higher than 35 °C, it is cooled by an atomized water curtain. Pressure segmented regulation: When spraying the bottom layer, the pressure is set at 18 - 20 MPa, and the moving speed of the spray gun is 0.7 - 0.8 m / s to form a continuous thin layer. When spraying the top layer, the pressure is increased to 21 - 22 MPa, and the moving speed of the spray gun is reduced to 0.5 - 0.6 m / s to enhance the directional arrangement of the nano-aluminum oxide filler. Trajectory optimization: The spray gun is kept perpendicular to the base surface, the spray distance is 300 - 350 mm, the swing amplitude of the spray gun is ≤ 50 mm, and the overlapping width of adjacent spraying bands is 1 / 3 - 1 / 2 of the spray width. Curing monitoring: The surface temperature of the coating is monitored within 30 minutes after spraying is completed. The heating rate is controlled at ≤ 5 °C / min, the peak temperature is ≤ 60 °C, and the relative humidity during curing is ≤ 75%.

8. The prefabricated wharf structure according to claim 1, characterized in that, The silane-based corrosion inhibitor incorporated into the pile body concrete of the composite pile foundation assembly is a two-component composite silane, which includes isobutyltriethoxysilane with a mass proportion of 60%-70% and octyltrimethoxysilane with a mass proportion of 30%-40%. The total dosage is 0.8%-1.2% of the total mass of the cementitious materials.

9. The prefabricated wharf structure according to claim 8, wherein, The silane corrosion inhibitor is injected into the pile body concrete by the vacuum pressure impregnation method. The impregnation pressure is 0.5-0.8 MPa, the impregnation time is 2-3 hours, and the post-impregnation curing is carried out at normal temperature for 48 hours. The coarse aggregate of the pile body concrete is granite gravel with a particle size of 10-20 mm, the fine aggregate is river sand with a fineness modulus of 2.3-2.6, the water-binder ratio is 0.28-0.32, and 8%-12% of slag powder and 5%-8% of metakaolin are incorporated into the total mass of the cementitious materials. After being treated with silane, the surface water absorption rate of the pile body concrete is ≤0.01 mm / min¹ / ², the chloride ion migration coefficient is ≤3.0×10⁻¹² m² / s, and the anti-sulfate erosion grade is ≥KS150. A transition sealing belt is arranged at the junction of the epoxy resin coating and the silane treatment layer of the pile top anchoring steel bar. The sealing belt is formed by continuously coating a silane-modified polyurethane colloid with a width of 15-20 mm and a thickness of 1.0-1.5 mm.

10. A construction method for an assembled wharf structure, characterized in that, It includes the following steps: The precast concrete cap unit is cast and formed with fiber-reinforced concrete with a fiber volume fraction of 1.2%-1.8%, and trapezoidal steel rails are embedded on the side of the cap unit. Epoxy mortar is filled at the joints between adjacent precast concrete cap units. The epoxy mortar is added with short-cut basalt fibers with a length of 12-15 mm and a diameter of 7-9 μm and hydrophobic nano-silica. The surface of the short-cut basalt fibers is treated with a silane coupling agent. The fiber dosage is 1.5-2.0 kg / m³. The particle size of the hydrophobic nano-silica is 10-20 nm, the specific surface area is 180-220 m² / g, the dosage is 3%-5% of the total mass of the cementitious materials, and the nano-silica is hydrophobically modified with methyltrimethoxysilane. The dosage of the modifier is 1.5%-2.0% of the mass of the nano-silica. A polyurea waterproof coating is applied to the surface of the joint after the epoxy mortar is cured, and the coating thickness is controlled to be 2.0-2.5 mm. When preparing the composite pile foundation assembly, a silane-based corrosion inhibitor is incorporated into the pile body concrete of the prestressed concrete pipe pile, and the dosage is 0.8%-1.2% of the total mass of the cementitious materials. Anchor steel bars are embedded at the pile top, and the surface of the anchor steel bars is coated with an epoxy resin layer. When preparing the elastic fender module, a three-layer composite structure is made of closed-cell rubber and polyurethane composite elastomer. The outer layer is a weather-resistant polyurethane layer, the middle layer is a closed-cell rubber foam body, and the inner layer is a high-damping butyl rubber layer. The three layers are integrally formed by vulcanization bonding, and a T-shaped groove with a depth of 1 / 3 of the module thickness is processed on the back of the module. The T-shaped groove of the elastic fender module is fitted and connected with the trapezoidal steel rail on the side of the precast concrete cap unit.

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