Surface treatment method for weathering-resistant steel bridge

Abstract

The weathering steel bridge surface treatment method comprises the steps that 1, high-pressure water jet is adopted to conduct lossless cleaning on the surface of weathering steel; and step 2, accelerating the formation and stabilization of the weather-proof layer by adopting a periodic spraying mode. The technical problem of how to achieve environment-friendly treatment of the surface of the weathering resistant steel is solved, environment-friendly treatment of the surface of the weathering resistant steel is achieved, the requirements of age development are met, on one hand, oil stains, rust scales and the like on the surface of the weathering resistant steel can be removed, the purpose of cleaning the surface of the weathering resistant steel is achieved, and on the other hand, a surface stabilization rust layer can be formed in a periodic spraying mode; through tests, the surface stabilization rust layer is stable and reliable, and the durability requirement is met; in addition, the method is high in practicability, high in efficiency, low in cost, high in rust removal quality and free of environmental pollution, and belongs to an energy-saving and environment-friendly surface treatment method.

Description

Technical Field

[0001] The present invention specifically relates to a surface treatment method for a weathering steel bridge. Background Art

[0002] With the rapid development of transportation engineering in my country, the application of new material weathering steel is also being vigorously promoted. In western my country, a large number of weathering steel bridges have been designed to better protect the environment. After long-term use in the atmospheric environment, weathering steel can form a protective and stable rust layer on its surface, which has the ability to resist atmospheric corrosion. To improve the durability of weathering steel bridges, a stabilized rust layer must be formed on the surface of the steel bridge before installation. Before the rust layer stabilization treatment, the surface of the steel beam must also be cleaned, including surface oil stains, rust stains, etc.

[0003] Traditional methods for cleaning and rust removal on steel structures include mechanical rust removal and sandblasting. Mechanical rust removal has a limited scope of application; sandblasting is inefficient and costly, and it also produces significant dust pollution. The purpose of sandblasting is to create a certain degree of roughness on the surface of steel bridges, thereby creating a strong bond between the paint and the steel beams. However, weathering steel bridges do not require this roughness; only surface oil and rust need to be removed. Therefore, with the development of the times, and especially due to environmental restrictions, sandblasting is no longer a suitable rust removal method for weathering steel. To address this, the following technical solutions are proposed. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a surface treatment method for weathering steel bridges, and solve the technical problem of how to achieve environmentally friendly treatment of weathering steel surfaces.

[0005] The technical solution adopted by the present invention is a surface treatment method for a weathering steel bridge, comprising the following steps:

[0006] Step 1: Use high-pressure water jet to clean the surface of weathering steel without damage;

[0007] Step 2: Use periodic spraying to accelerate the formation and stabilization of the weathering layer.

[0008] The step 1 comprises the following steps:

[0009] Step 101: The fan-shaped water flow becomes a blade, cutting the dense object to form cracks;

[0010] Step 102: High-pressure water penetrates the cracks and encounters the high-temperature parent material, causing rapid vaporization and evaporation, creating an explosion-like effect, separating the iron oxide scale from the parent material;

[0011] Step 103: After being impacted by water, the rust contracts when cooled, generating a transverse shear force, causing the rust to separate from the matrix;

[0012] Step 104: The loose iron scale is washed away by the water jet with a forward tilt angle.

[0013] In the above technical solution, preferably: in step 1, ultra-high pressure water jet equipment is used to achieve non-destructive cleaning; the power is 120kw / 161HP to 225kw / 301HP; the water gun pressure is 200 to 300Mpa; and the flow rate is 25L / min to 50L / min.

[0014] In the above technical solution, preferably: the water gun head of the cleaning machine of the ultra-high pressure water jet equipment forms an angle of 35° to 45° with the surface of the weathering steel; the water gun head of the cleaning machine is connected to the water tank; the number of water gun heads of the cleaning machine is 2 to 4.

[0015] The above technical solution further includes a water recovery and treatment system; the water recovery and treatment system includes a drainage area, a drainage area, a three-stage sedimentation tank and a sewer network; the water flows from the drainage area through the drainage area and then flows to the three-stage sedimentation tank, and is purified step by step in the three-stage sedimentation tank before being discharged into the sewer network.

[0016] In the above technical solution, further: the three-stage sedimentation tank recycles the cleaned rust and scale for secondary utilization; the three-stage sedimentation tank is composed of three sedimentation units connected in series, and the three sedimentation units use the principle of gravity sedimentation to grade and precipitate the particulate matter in the wastewater according to the particle size and density differences, and finally meet the discharge or reuse standards.

[0017] In the above technical solution, preferably: the drainage area and the diversion area use "comb-shaped" drainage grooves to achieve drainage and diversion; and steel bridges are evenly and neatly arranged above the drainage area.

[0018] The advantages of the present invention compared with the prior art are:

[0019] 1. The present invention realizes the environmentally friendly treatment of the surface of weathering steel, conforming to the development needs of the times. On the one hand, it can remove oil stains, rust stains, etc. on the surface of weathering steel to achieve the purpose of cleaning the surface of weathering steel. On the other hand, it can form a surface stabilized rust layer through periodic spraying. Through experiments, the surface stabilized rust layer is stable and reliable, meeting the durability requirements.

[0020] 2. The present invention has strong practicality, high efficiency, low cost, high rust removal quality, and will not cause environmental pollution. It is an energy-saving and environmentally friendly surface treatment method.

[0021] 3. The gun head of the present invention is tilted at an angle of 35° to 45°, which can optimize the impact force distribution, efficiently remove dirt, reduce surface damage, expand the cleaning area, promote dirt removal, and improve cleaning efficiency; it can also adapt to complex structures and enhance operational flexibility.

[0022] 4. The water gun head of the cleaning machine of the present invention is connected to the water tank. The setting of the water tank can achieve continuous high-pressure output, reduce external dependence, and ensure stable water supply; the water tank can be integrated with pre-treatment devices such as filtration and sedimentation to realize water quality pre-treatment function and optimize water quality control; for specific dirt (such as oil stains), the water tank can be added with environmentally friendly cleaning agents to achieve efficient decontamination through water mixing.

[0023] 5. The 2 to 4 water gun heads of the cleaning machine of the present invention can not only shorten the construction period, but also achieve cleaning coverage of complex structures, ensuring cleaning without dead angles; it can also avoid single-point overload and dynamically adjust the working intensity according to the degree of dirt.

[0024] 6. In the surface treatment project of the weathering steel bridge of the present invention, the water recovery and treatment system realizes the efficient recycling of water resources and environmentally friendly construction through the synergistic effect of the drainage area, diversion area, tertiary sedimentation tank and sewer network, which conforms to the design concept of environmental protection, high efficiency, system and economy.

[0025] 7. The present invention adopts a "comb-shaped" drainage trough to achieve drainage and drainage, and arranges steel bridges evenly and neatly above the drainage area, which is conducive to efficient drainage and drainage, facilitates efficient purification in the subsequent tertiary sedimentation tank, and is easy to maintain and clean; the steel bridges are evenly and neatly arranged above the drainage area, optimizes space utilization, improves construction efficiency, reduces interference, uniformly bears force, facilitates construction management and quality control, is beautiful and environmentally friendly, achieves efficient coordination of drainage, drainage and construction, improves overall construction efficiency, improves construction quality, reduces construction costs, and enhances environmental protection performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of the water recovery and treatment system of the present invention;

[0027] Figure 2 for Figure 1 A partial enlarged detail of the tertiary sedimentation tank;

[0028] In the figure: 1-drainage area, 2-drainage area, 3-tertiary sedimentation tank, 301-sedimentation unit, 4-sewer network, 5-steel bridge, 6-water tank. DETAILED DESCRIPTION

[0029] The following is a combination of the embodiments of the present invention Figure 1-2 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0030] A surface treatment method for a weathering steel bridge comprises the following steps:

[0031] Step 1: Use high-pressure water jet to clean the surface of weathering steel without damage;

[0032] Step 2: Use periodic spraying to accelerate the formation and stabilization of the weathering layer.

[0033] It should be noted that the non-destructive cleaning of the high-pressure water jet in step 1 of the present invention only relies on the physical flushing of high-pressure water flow, does not require chemical cleaning agents, avoids pollution to the environment, and meets the requirements of green construction. High-pressure water flow can quickly strip off rust, oil stains and impurities on the surface of weathering steel, and the cleaning efficiency is much higher than traditional manual polishing or sandblasting, and the cleaning efficiency is high. High-pressure water jet is a relatively non-contact cleaning method, which will not cause mechanical damage to the surface of weathering steel or change its microstructure, and retains the original mechanical properties of the steel. Due to non-destructive cleaning, additional repair or pretreatment steps caused by surface damage are avoided, reducing the overall construction cost. High-pressure water jet equipment can be equipped with nozzles of different angles and shapes, which is suitable for cleaning complex curved surfaces, gaps and dead corners of bridges to ensure uniform and consistent treatment effects.

[0034] The periodic spraying operation in step 2 of the present invention can simulate natural rainfall and humidity changes, promote the rapid formation of an oxide layer on the surface of weathering steel, and shorten the natural corrosion cycle; by adjusting the spraying frequency, water volume, and chemical composition (such as adding a small amount of accelerator), the thickness and uniformity of the weathering layer can be accurately controlled to ensure its protective performance. Periodic spraying can promote the formation of stable compounds such as α-FeOOH in the oxide layer, reduce the content of loose γ-FeOOH, and improve the density and corrosion resistance of the weathering layer. By accelerating the formation of the weathering layer, the early rust liquid sagging phenomenon can be effectively suppressed to avoid pollution to the surrounding environment and structure of the bridge. The stable and dense weathering layer can significantly improve the corrosion resistance of weathering steel bridges, extend their service life, and reduce the frequency of later maintenance and repairs.

[0035] It can be seen that the combination of high-pressure water jet cleaning and periodic spraying achieves efficient, non-destructive, and environmentally friendly surface treatment, while reducing construction and long-term maintenance costs. By accelerating the formation and stabilization of the weathering layer, the corrosion resistance of weathering steel bridges is significantly improved, and the service life of the structure is extended. This method is suitable for weathering steel bridges of various complex structures, with uniform and consistent treatment effects and good engineering applicability. The surface treatment method for weathering steel bridges accelerates the formation of the weathering layer through non-destructive cleaning with high-pressure water jets and periodic spraying, combining the advantages of high efficiency, environmental protection, low cost, and high weathering resistance, providing reliable technical support for the construction and maintenance of weathering steel bridges.

[0036] In the above embodiment, preferably, step 1 uses ultra-high pressure water jet equipment to achieve non-destructive cleaning; the power is 120kw / 161HP to 225kw / 301HP; the water gun pressure is 200 to 300Mpa; and the flow rate is 25L / min to 50L / min.

[0037] Example 1: In step 1, ultra-high pressure water jet equipment is used to achieve non-destructive cleaning; power is 120kw / 161HP; water gun pressure is 200Mpa; flow rate is 25L / min.

[0038] Example 2: In step 1, ultra-high pressure water jet equipment is used to achieve non-destructive cleaning; power is 173kw / 231HP; water gun pressure is 250Mpa; flow rate is 38L / min.

[0039] Example 3: In step 1, ultra-high pressure water jet equipment is used to achieve non-destructive cleaning; power is 225kw / 301HP; water gun pressure is 300Mpa; flow rate is 50L / min.

[0040] It should be noted that ultra-high-pressure water jet equipment can generate water gun pressures as high as 200-300 MPa. This high-pressure water flow has a powerful impact, quickly stripping away rust, oil stains, and impurities from the surface of weathering steel, achieving efficient cleaning. At the same time, the flow rate is controlled at 25L / min to 50L / min, ensuring effective cleaning while avoiding water waste. By adjusting the water gun pressure and flow rate, precise control of the cleaning process can be achieved. For example, the pressure or flow rate can be increased in areas requiring focused cleaning, while it can be reduced in areas with higher surface requirements to avoid unnecessary damage to the substrate.

[0041] In the above embodiment, preferably: the water gun head of the cleaning machine of the ultra-high pressure water jet equipment forms an angle of 35° to 45° with the surface of the weathering steel; the water gun head of the cleaning machine is connected to the water tank 6; the number of the water gun heads of the cleaning machine is 2 to 4.

[0042] It should be noted that the 35° to 45° angle design enables the high-pressure water flow to impact the surface of weathering steel at the optimal angle, ensuring sufficient impact force while avoiding the problem of water rebound due to a too small angle or the dispersion of impact force due to an excessively large angle. This angle design helps to more effectively remove rust, oil, and impurities from the surface. Compared with vertical impact, oblique impact can reduce the direct impact force on the surface of weathering steel, thereby reducing the risk of surface damage and maintaining the original performance and appearance of the steel. Oblique impact can enable the water flow to form a wider coverage area on the surface of weathering steel, improving cleaning efficiency. Oblique water flow can better penetrate into the tiny gaps and bumps on the surface, thoroughly removing hidden dirt. In the cleaning of complex structures such as bridges, oblique impact can better adapt to surfaces of different angles and shapes, improving the flexibility and convenience of operation.

[0043] It should be noted that: Water tank 6 serves as a water reserve, which can ensure that the ultra-high pressure water jet equipment obtains a stable water supply during continuous operation, avoiding pressure fluctuations or equipment shutdowns caused by insufficient water. The design of water tank 6 reduces dependence on external water sources, improves the independence and mobility of the equipment, and is suitable for construction sites in remote areas or with inconvenient water sources. Water tank 6 can be integrated with pre-treatment devices such as filtration and sedimentation to remove impurities and particulate matter in the water, ensure the cleanliness of the water entering the high-pressure pump, extend the service life of the equipment and improve the cleaning effect. Water tank 6 can be linked with a pressure regulating device to adjust the output pressure in real time according to cleaning needs to avoid energy waste. Compared with remote pumping, taking water directly from water tank 6 reduces pipeline pressure loss and improves equipment energy efficiency.

[0044] It should be noted that 2 to 4 gun heads can clean different areas at the same time, significantly shortening the overall processing time of large structures such as bridges. For example, operations can be carried out simultaneously on the flange plates, webs and bottom plates of bridges to avoid the extension of construction period caused by single-point operations. The multi-gun head diversion design reduces the flow and pressure requirements of a single gun head, reduces local wear of high-pressure pumps and pipelines, extends the equipment water tank pretreatment and pressure regulation functions to reduce equipment failure rate, and the multi-gun head diversion design extends component life and comprehensively reduces the cost life of the entire life cycle. The number of gun heads can be increased or decreased according to the degree of dirt (such as local heavy rust areas), and the operation mode can be dynamically adjusted to ensure cleaning quality.

[0045] As can be seen, through oblique impact, stable water supply, and multi-nozzle coordination, efficient and non-destructive deep cleaning of the weathering steel surface is achieved, providing a high-quality foundation for the subsequent formation of the weathering layer. The water tank pretreatment and multi-nozzle diversion design extend component life and comprehensively reduce lifecycle costs. By combining these technical advantages, this ultra-high-pressure water jet equipment configuration can significantly improve the efficiency, quality, and cost-effectiveness of weathering steel bridge surface treatment, providing reliable support for the durability of bridge projects.

[0046] In the above embodiment, further: a water recovery and treatment system is also included; the water recovery and treatment system includes a drainage area 1, a drainage area 2, a tertiary sedimentation tank 3 and a sewer network 4; water flows from the drainage area 1 through the drainage area 2 and is then drained and collected and uniformly flows to the tertiary sedimentation tank 3, and is purified step by step in the tertiary sedimentation tank 3 before being discharged into the sewer network 4.

[0047] It should be noted that this invention utilizes a three-stage sedimentation tank, which can purify 80% to 95% of construction wastewater. The purified water meets the Class I standard of the Integrated Wastewater Discharge Standard (GB 8978-1996), with a suspended solids (SS) removal rate exceeding 90%, thus preventing pollution to surrounding water bodies. This eliminates wastewater accumulation at the construction site, reduces the risk of slips, and improves the working environment.

[0048] In the above embodiment, further: the tertiary sedimentation tank 3 recycles the cleaned rust for secondary utilization; the tertiary sedimentation tank 3 is composed of three sedimentation units 301 connected in series, and the three sedimentation units use the principle of gravity sedimentation to grade and precipitate the particulate matter in the wastewater according to the particle size and density differences, and finally meet the discharge or reuse standards.

[0049] It should be noted that tertiary sedimentation tanks gradually separate suspended solids in wastewater through physical sedimentation, achieving solid-liquid separation and pollutant removal. Their core function is to utilize the principle of gravity sedimentation to grade and precipitate particulate matter in wastewater based on particle size and density, ultimately meeting discharge or reuse standards. The primary sedimentation tank (primary sedimentation tank) removes larger suspended solids from the wastewater; the secondary sedimentation tank (secondary sedimentation tank) further removes medium-sized suspended solids; and the tertiary sedimentation tank (final sedimentation tank) removes remaining suspended solids and some soluble pollutants.

[0050] In the above embodiment, preferably: the drainage area 1 and the drainage area 2 use "comb-shaped" drainage grooves to achieve drainage and drainage; and the steel bridges 5 are evenly and neatly arranged above the drainage area 1.

[0051] It should be noted that the comb-tooth-shaped drainage troughs can quickly direct water from drainage area 1 to drainage area 2, preventing water accumulation and ensuring a dry construction area. The comb-tooth structure evenly distributes water within the troughs, preventing scouring caused by localized excessive water pressure. This helps to create a stable water flow path, facilitating efficient purification in the subsequent tertiary sedimentation tank 3. The comb-tooth structure makes debris within the troughs easily accessible and removable by cleaning tools, reducing maintenance costs. The uniform and orderly layout of the steel bridges 5 fully utilizes the construction area, facilitating the movement and operation of construction equipment and personnel, and improving construction efficiency. This neat layout reduces interference during construction, improving efficiency and quality, and minimizing disruptions. The uniform layout of the steel bridges 5 also ensures more uniform load distribution above drainage area 1, reducing localized stress concentrations, enhancing overall structural stability, and ensuring uniform load distribution. The uniform and orderly layout of the steel bridges 5 facilitates standardized construction, improving construction quality and consistency. This neat layout also facilitates and accurately detects and corrects problems promptly. The neat layout of steel bridges enhances the overall image of the construction site and reflects the company's professionalism and management level.

[0052] It can be seen that the combination of the "comb-shaped" drainage trough and the uniform and neat layout of the steel bridge 5 achieves efficient coordination of drainage, diversion and construction, and improves the overall construction efficiency. The optimized drainage system and stable construction structure help to improve the construction quality of the surface treatment of the weathering steel bridge and reduce problems caused by water accumulation or structural instability. By reducing the risk of blockage, reducing maintenance costs, and improving construction efficiency, this solution helps to reduce the overall construction cost. The efficient drainage system and reduced environmental impact reflect the environmental performance of the solution and meet the requirements of green construction. The solution of using "comb-shaped" drainage troughs to achieve drainage and diversion, and evenly and neatly arranging the steel bridge 5 above the drainage area 1, not only improves construction efficiency and quality, but also reduces construction costs and environmental impact. It is an important development direction for green construction and efficient construction in the future.

[0053] The working principle of the present invention is as follows: First, the present invention utilizes ultra-high pressure water jet equipment (the jet impacts the surface to be cleaned at supersonic speed, and removes scale, sediment, etc. from the surface through scouring, chopping, shearing, etc., to achieve the cleaning purpose; its kinetic energy can not only remove oil, grease, rust, etc. on the surface of the component, but also the flushing medium is water, and the high-flow booster is driven by the motor group, and the pure water is pressurized by the high-pressure plunger pump, for example, the water is pressurized to a pressure of 200-300Mpa, and the high-pressure water flow is ejected through the fan-shaped nozzle. When the high-pressure water flow hits When it reaches the surface of the component, the following process will occur: that is, step 1 includes the following steps: step 101, the fan-shaped water flow becomes a blade, cutting the dense object to form a crack; step 102, the high-pressure water passes through the crack and encounters the high-temperature parent material, rapidly vaporizing and evaporating, forming an effect similar to an explosion, and peeling off the iron oxide scale and the parent material; step 103, the rust shrinks when it is cooled after being impacted by water, generating a lateral shear force, which causes the rust to peel off from the parent material; step 104, under the scouring action of the water jet with a forward tilt angle, the loose iron scale is washed away.

[0054] Next, the washed surface oil, rust, and other dirt are discharged through drainage area 1 and drainage area 2 into tertiary sedimentation tank 3. After being purified step by step in tertiary sedimentation tank 3, the water is discharged through sewer network 4. Finally, the cleaned steel bridge 5 is periodically sprayed with water to form the desired stabilized rust layer. Furthermore, the rust removed from the surface of the steel bridge 5 can be recycled and processed for resource recovery.

[0055] From the above description, we can find that: the present invention abandons the traditional sandblasting method of weathering steel bridge surface rust removal, and adopts ultra-high pressure water jet surface cleaning to remove oil and rust. This method has a significant rust removal effect and is more environmentally friendly and efficient than chemical rust removal, manual rust removal and other methods. It has higher rust removal efficiency, lower cost and higher cost performance than sandblasting. Specifically, according to experimental tests, the rust removal efficiency can reach 25m per hour. 2 The rust removal effect is as high as Sa3.0 level, meeting the highest level requirement for rust removal of steel structures. Not only that, the high-pressure water jet rust removal method will not cause damage to the steel plate, and the spraying operation after rust removal can easily stabilize the formation of the rust layer.

[0056] In summary, the present invention has strong practicality, high efficiency, low cost, high rust removal quality, and will not cause environmental pollution. It is an energy-saving and environmentally friendly surface treatment method and is suitable for promotion.

[0057] It should be understood that although this specification is described according to one embodiment, this embodiment does not only include one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in this embodiment can also be appropriately arranged and combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A surface treatment method for weathering steel bridges, characterized in that: The steps include: Step 1: Use high-pressure water jet to clean the surface of weathering steel without damage; Step 2: Use periodic spraying to accelerate the formation and stabilization of the weathering layer; The step 1 comprises the following steps: Step 101: The fan-shaped water flow becomes a blade, cutting the dense object to form cracks; Step 102: High-pressure water penetrates the cracks and encounters the high-temperature parent material, causing rapid vaporization and evaporation, creating an explosion-like effect, separating the iron oxide scale from the parent material; Step 103: After being impacted by water, the rust contracts when cooled, generating a transverse shear force, causing the rust to separate from the matrix; Step 104: The loose iron scale is washed away by the water jet with a forward tilt angle.

2. The surface treatment method for weathering steel bridges according to claim 1, characterized in that: In step 1, ultra-high pressure water jet equipment is used to achieve non-destructive cleaning; the power is 120kw / 161HP to 225kw / 301HP; the water gun pressure is 200 to 300Mpa; and the flow rate is 25L / min to 50L / min.

3. The surface treatment method for weathering steel bridge according to claim 2, characterized in that: The water gun head of the cleaning machine of the ultra-high pressure water jet equipment forms an angle of 35° to 45° with the surface of the weathering steel; the water gun head of the cleaning machine is connected to the water tank (6); and the number of water gun heads of the cleaning machine is 2 to 4.

4. The surface treatment method for weathering steel bridges according to claim 1, 2 or 3, characterized in that: The invention also includes a water recovery and treatment system; the water recovery and treatment system includes a drainage area (1), a drainage area (2), a three-stage sedimentation tank (3) and a sewer pipe network (4); water flows from the drainage area (1) through the drainage area (2) and then flows to the three-stage sedimentation tank (3) after being drained and collected, and is purified step by step in the three-stage sedimentation tank (3) before being discharged into the sewer pipe network (4).

5. The surface treatment method for weathering steel bridge according to claim 4, characterized in that: The tertiary sedimentation tank (3) recycles the cleaned rust scale for secondary use; the tertiary sedimentation tank (3) is composed of three sedimentation units (301) connected in series, and the three sedimentation units (301) use the principle of gravity sedimentation to grade and precipitate particulate matter in the wastewater according to particle size and density differences, ultimately meeting discharge or reuse standards.

6. The surface treatment method for weathering steel bridge according to claim 4, characterized in that: The drainage area (1) and the drainage area (2) use "comb-shaped" drainage grooves to achieve drainage and drainage; steel bridges (5) are evenly and neatly arranged above the drainage area (1).

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