Process for eliminating air holes of shield tunnel duct piece

Abstract

The invention discloses a process for eliminating shield tunnel duct piece air holes, and belongs to the technical field of building construction corrosion prevention. Comprising the steps that after pipe pieces are poured, steam curing is completed, and a pipe piece production line is hoisted out; the outer surface of the duct piece is checked, and surface grooves are manually filled with high-grade mortar; the duct piece is hoisted out after being hoisted into a water pool for maintenance; polishing small particles on the surface of the duct piece, and then flushing and air-drying; anti-corrosion paint is sprayed for the first time, air holes are formed after the paint is dried and shrunk, and the paint at the air holes is manually flattened through a scraper; manually smearing and filling the anticorrosive paint mixture in the air holes by using a scraper; and spraying for the second time to eliminate air holes. Reinforced concrete pipe piece anti-corrosion construction is an important link for ensuring safety and construction quality of a tunnel structure penetrating through a tunnel with a corrosion geological section, the process is suitable for anti-corrosion paint spraying construction of a reinforcing steel bar or concrete structural surface, the process is simple and easy to operate, batch flow construction is facilitated, and the construction efficiency is improved. The method plays an important role in corrosion prevention construction of tunnel reinforcing steel bars or concrete segments, and solves the problem of corrosion prevention quality of the segments.

Description

Technical Field

[0001] The invention belongs to the technical field of anti-corrosion in building construction, in particular to the technical field of anti-corrosion construction for shield segments, and is particularly suitable for an anti-corrosion construction process for eliminating pores in anti-corrosion spray paint on the surface of reinforced concrete structure segments. Background Art

[0002] In shield tunnel projects, the segment support always follows the shield surface. The segment is a prefabricated part of a reinforced concrete structure. The geological conditions of shield tunnels are complex, and some geology is corrosive to reinforced concrete. Anti-corrosion treatment of the surface of reinforced concrete segments is a common engineering quality and safety protection measure, which is of great significance for ensuring the stability and service life of the tunnel structure.

[0003] However, in the construction of anti-corrosion spray paint, the traditional anti-corrosion spray paint has many pores and affects the anti-corrosion effect.

[0004] The presence of protruding small particles or grooves on the surface of the segment concrete will cause pores in the spray paint. If the spray equipment evenly sweeps over the protruding concrete particles, uneven paint thickness will appear between the protruding small particles and the adjacent surfaces, and the paint cannot completely cover the top surface or side surface of the particles, forming pores. Similarly, grooves will also form pores.

[0005] When spraying anti-corrosion paint, there are rice-grain-sized pores on the smooth concrete surface. The evenly swept paint will shrink in the process of changing from a fluid state to a dry film. These rice-grain-sized pores cause the paint to collapse and form pores during the shrinkage process.

[0006] Spraying air pressure control. If the spraying air pressure is too low, the paint will appear in lines or large particles when it is sprayed out of the spray gun nozzle. The difference in the size of the paint particles makes the thickness of the paint attached to the concrete surface of the pipe segment vary greatly, and the paint dries unevenly and pores appear.

[0007] The impact of insufficient spraying times. Since it is difficult to achieve 100% uniformity when spraying anti-corrosion paint manually, the anti-corrosion process requires at least two sprayings at intervals. If the anti-corrosion paint is only sprayed for the first time, the probability of pores being generated due to other factors will increase.

[0008] Therefore, improving the anti-corrosion construction technology of shield tunnel segments and eliminating the quality problem of pores appearing when spraying paint on the concrete surface are of great significance to improving tunnel construction quality and reducing safety risks. Summary of the invention

[0009] The present invention discloses a process for eliminating air holes in shield tunnel segments based on the deficiencies of the prior art. The purpose of the present invention is to provide a process for eliminating air holes in shield tunnel segments, so as to solve the problem that air holes appear in reinforced concrete shield segments during anti-corrosion paint spraying, which affects the anti-corrosion quality.

[0010] The present invention is achieved through the following technical solutions:

[0011] A process for eliminating air holes in shield tunnel segments, characterized by comprising the following process steps:

[0012] S1. After the casting of the pipe segments is completed, the pipe segments are hoisted out of the production line after steam curing;

[0013] S2. Check the outer surface of the segment and manually fill the surface grooves with high-grade mortar;

[0014] S3, hoist the pipe segments into the water tank for curing and then hoist them out;

[0015] S4, grind small particles on the surface of the pipe segment, rinse and air dry after completion;

[0016] S5. When the first coat of anti-corrosion paint is sprayed, pores will appear after the paint shrinks and the paint at the pores will be smoothed with a scraper manually;

[0017] S6. Use a scraper to manually fill the anti-corrosion paint mixture into the pores;

[0018] S7. Spray the second time to eliminate pores.

[0019] Furthermore, the anti-corrosion paint mixture in step S6 is a mixture of conventional anti-corrosion paint and quartz fine sand.

[0020] In the step S4, a hand-held vacuum polisher is used for polishing, so that small particles are polished and the unevenness of the concrete surface is eliminated.

[0021] The process of the present invention includes eliminating pores caused by small grooves and small particles on the surface of the pipe segment concrete, eliminating pores caused by small pores on the surface of the pipe segment during the shrinkage process of paint, eliminating pores caused by low spraying mechanical pressure, and eliminating pores caused by uneven spraying.

[0022] The process of the present invention eliminates small grooves on the surface of the pipe segment concrete: after the cast concrete of the pipe segment solidifies and before entering the water tank for curing, an inspection and repair process of the pipe segment concrete surface is added. If grooves are found during the inspection, they are immediately repaired with prepared mortar to make them smooth with the surrounding area. After the repair is completed, the pipe segment is immediately put into the water tank for curing.

[0023] The process of the present invention eliminates small particles on the surface of the pipe segment concrete: the small particles are usually only a few millimeters in size and are protrusions that appear when the surface is manually plastered. They often appear at the edges of the pipe segment and are less common in the middle. They are manually polished using a handheld vacuum grinder to eliminate the protrusions and unevenness on the concrete surface while polishing the small particles.

[0024] The process of the present invention eliminates small pores on the surface of the segment concrete: large pores can be eliminated in the inspection and repair process like grooves, and the diameter of small pores is ≤3mm. The small pores are eliminated by manually filling the pores with an anti-corrosion paint mixture before spraying with a sprayer. The anti-corrosion paint mixture is a mixture of conventional anti-corrosion paint and quartz fine sand.

[0025] The process of the present invention eliminates the pores caused by low pressure of the spraying machine: through the comparison of spraying practice of various spraying machines on site, the output pressure is 250-300kgf. If the pressure is lower than 250kgf, the paint will be sprayed in lines or the paint particles will be uneven in size, and if the pressure is higher, the paint will be ejected.

[0026] The number of spraying times of the process of the present invention is: it is still difficult to solve the pore problem 100% by manual spraying. A small number of pores will appear during the shrinkage process of the paint and before the surface is dry. In this process, the pores are eliminated by manually holding a scraper to wipe the surface in the pore area, and then spraying a second time to solve the pore problem. When the temperature is high (summer), the time difference between the two times is 30 to 60 minutes, and when the temperature is low (winter), the time difference between the two times is 60 to 90 minutes.

[0027] In the process of the present invention, the concrete surface is polished with a hand-held vacuum polisher, then rinsed with water, and sprayed after the surface is dry, so that the first spraying will produce very few pores. After the pores are smoothed with a hand-held scraper, the second spraying can completely eliminate the pores.

[0028] In shield construction, the anti-corrosion construction of reinforced concrete segments is an important link to ensure the safety and construction quality of tunnel structures passing through corrosive geological sections. The process of the present invention is suitable for the anti-corrosion paint spraying construction of reinforced or concrete structural surfaces. The process of the present invention is simple, easy to operate, and convenient for batch flow construction. It plays an important role in the anti-corrosion construction of tunnel reinforced or concrete segments and solves the anti-corrosion quality problem of the segments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with specific implementation methods. The specific implementation methods are further descriptions of the principles of the present invention and do not limit the present invention in any way. Technologies that are the same or similar to the present invention do not exceed the scope of protection of the present invention.

[0031] In shield construction, the main goal of the anti-corrosion construction of reinforced concrete segments is to ensure that the segment concrete is not corroded and to ensure the stability and safety of the segment. The anti-corrosion construction is completed by spraying anti-corrosion paint on the surface of the segment. The anti-corrosion paint adheres to the concrete surface of the segment to form a closed layer of paint film, which prevents corrosive groundwater or rock and soil from corroding the segment concrete in the tunnel. However, when the anti-corrosion paint is sprayed on the surface of the segment concrete, many pores often appear, which will make the anti-corrosion paint lose its function of protecting the segment concrete. Therefore, it is necessary to change the anti-corrosion construction process of the concrete segment and eliminate the pores that appear after spraying the paint.

[0032] The process of the present invention provides the following method to eliminate the pores that appear after spraying paint:

[0033] S1. After the casting of the pipe segments is completed, the pipe segments are hoisted out of the production line after steam curing;

[0034] S2. Check the outer surface of the segment and manually fill the surface grooves with high-grade mortar;

[0035] S3, hoist the pipe segments into the water tank for curing and then hoist them out;

[0036] S4, grind small particles on the surface of the pipe segment, rinse and air dry after completion;

[0037] S5. When the first coat of anti-corrosion paint is sprayed, pores will appear after the paint shrinks and the paint at the pores will be smoothed with a scraper manually;

[0038] S6. Use a scraper to manually fill the anti-corrosion paint mixture into the pores;

[0039] S7. Spray the second time to eliminate pores.

[0040] The anti-corrosion paint mixture in step S6 is a mixture of conventional anti-corrosion paint and quartz fine sand.

[0041] In step S4, a manual handheld vacuum polisher is used for polishing, and the protrusions and unevenness of the concrete surface are eliminated while polishing small particles.

[0042] In shield construction, the anti-corrosion construction of reinforced concrete segments is an important link to ensure the safety and construction quality of tunnel structures passing through corrosive geological sections. The process of the present invention is suitable for the anti-corrosion paint spraying construction of steel bars or concrete structure surfaces, and solves the air hole problem that occurs in the manual anti-corrosion paint spraying construction of reinforced concrete shield segments, including the quality problems caused by small particles protruding from the spraying surface, grooves, air holes on the spraying surface, the pressure of the spraying machine, the number of spraying times, etc.

Claims

1. A process for eliminating air holes in shield tunnel segments, characterized in that The process steps include: S1. After the casting of the pipe segments is completed, the pipe segments are hoisted out of the production line after steam curing; S2. Check the outer surface of the segment and manually fill the surface grooves with high-grade mortar; S3, hoist the pipe segments into the water tank for curing and then hoist them out; S4, grind small particles on the surface of the pipe segment, rinse and air dry after completion; S5. When the first coat of anti-corrosion paint is sprayed, pores will appear after the paint shrinks and the paint at the pores will be smoothed with a scraper manually; S6. Use a scraper to manually fill the anti-corrosion paint mixture into the pores; S7. Spray the second time to eliminate pores.

2. The process for eliminating air holes in shield tunnel segments according to claim 1 is characterized in that: The anti-corrosion paint mixture in step S6 is a mixture of conventional anti-corrosion paint and quartz fine sand.

3. The process for eliminating air holes in shield tunnel segments according to claim 1 is characterized in that: In the step S4, a manual handheld vacuum polisher is used for polishing, and the protrusions and unevenness of the concrete surface are eliminated while polishing small particles.

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