Anti-corrosion manufacturing process for tunnel shield concrete duct piece

Abstract

The invention discloses an anti-corrosion manufacturing process for a tunnel shield concrete segment, and belongs to the technical field of concrete segment manufacturing, and the anti-corrosion manufacturing process specifically comprises the following steps: S1, preparing raw materials, S2, preparing concrete, and uniformly mixing cement, aggregate, an additive and an anti-corrosion agent according to a preset ratio to form anti-corrosion concrete; s3, preparing a mold; s4, concrete pouring; s5, maintenance treatment; s6, demolding and trimming; s7, anti-corrosion coating treatment is conducted; s8, quality inspection; anti-corrosion is carried out in each step of the manufacturing formula, the manufacturing process and the external coating, so that the anti-corrosion performance of the overall structure of the prefabricated pipe piece is improved, cracks caused by corrosion of the prefabricated pipe piece are avoided, the service life of the prefabricated pipe piece is prolonged, and the safety performance of the prefabricated pipe piece is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete segment manufacturing, and in particular relates to an anti-corrosion manufacturing process for tunnel shield concrete segments. Background Art

[0002] Shield tunnel construction can quickly and continuously excavate tunnels under various geological conditions, greatly improving construction efficiency. However, the main supporting structure of shield tunnels: prefabricated segments, has been in the humid underground environment for a long time, and the corrosion phenomenon has become more serious.

[0003] The main reasons are as follows:

[0004] Environmental factors: The environment in which the tunnel is located contains corrosive substances, such as chloride ions in groundwater. Chloride ions are one of the main factors causing steel corrosion. They may penetrate into the pipe segments through the capillary pores or cracks in the concrete, causing the steel bars to rust and expand, and then cause the concrete to crack and peel. In addition, changes in humidity, pH, etc. in the air also cause corrosion to the pipe segments.

[0005] Concrete quality issues: Improper concrete mix ratio, insufficient density, cracks or pores, etc., will make it easier for corrosive substances to invade. For example, when producing pipe segments in a precast factory, the moisture in the concrete is easy to move to the junction of the mold side plate and the side of the pipe segment under the action of vibration and stay, causing plastic shrinkage on the surface of the concrete when it solidifies and hardens, and surface microcracks appear. In addition, the poor uniformity of concrete caused by the sinking of coarse aggregate and the floating of cement paste can also lead to the initiation and expansion of cracks. When there is a large temperature difference between the inside and outside of the concrete, a large temperature stress will be generated, and mortar cracks are prone to occur. Similarly, when the humidity in the air is low, the evaporation rate of water on the concrete surface is much faster than the exudation rate of internal water, resulting in more obvious shrinkage cracks. Summary of the invention

[0006] The purpose of the present invention is to propose an anti-corrosion manufacturing process for tunnel shield concrete segments in order to solve the problem that the existing prefabricated segments contain corrosive substances that easily lead to cracks in the prefabricated concrete segments, thus affecting their service life.

[0007] In order to achieve the above object, the present invention adopts the following technical solution: a tunnel shield concrete segment anti-corrosion manufacturing process, specifically comprising the following steps:

[0008] S1: raw material preparation, selecting concrete raw materials with corrosion resistance, the concrete raw materials including cement, aggregate, additives and anti-corrosion agents;

[0009] S2: concrete preparation, mixing the cement, the aggregate, the additive and the anti-corrosion agent evenly according to a predetermined ratio to form anti-corrosion concrete;

[0010] S3: Mould preparation: prepare corresponding moulds according to the shape and size of the tunnel shield concrete segments and ensure that the mould surface is smooth and flawless;

[0011] S4: Concrete pouring: pouring the prepared anti-corrosion concrete into the mold and fully vibrating it to ensure that the anti-corrosion concrete is evenly filled and bubbles are removed;

[0012] S5: curing treatment, curing the poured anti-corrosion concrete to promote the hardening of the concrete and the functioning of the anti-corrosion agent;

[0013] S6: demoulding and finishing, after the anti-corrosion concrete reaches a certain strength, demoulding operation is performed, and the surface of the tunnel shield concrete segment is finished to remove excess concrete and defects;

[0014] S7: Anti-corrosion coating treatment, coating one or more layers of anti-corrosion coating on the surface of the tunnel shield concrete segment;

[0015] S8: Quality inspection, quality inspection of the completed tunnel shield concrete segments, including appearance inspection, dimension measurement, corrosion resistance test, etc., to ensure that the product quality meets the design requirements.

[0016] As a further description of the above technical solution:

[0017] The mass ratios of the cement, the aggregate, the additive and the anticorrosive agent in the concrete raw materials in S2 are 75-80%, 15-20%, 1-2% and 2-5% respectively.

[0018] As a further description of the above technical solution:

[0019] The anti-corrosion agent in S1 is at least one of an organic silicon, a silicate or an epoxy resin anti-corrosion agent.

[0020] As a further description of the above technical solution:

[0021] During the concrete pouring process in S4, a high-frequency vibrator is used to vibrate the concrete to improve the density and anti-corrosion effect of the concrete.

[0022] As a further description of the above technical solution:

[0023] The corrosion resistance test in S8 adopts salt spray test, acid and alkali immersion test or chemical corrosion test method.

[0024] As a further description of the above technical solution:

[0025] Before the S7 anti-corrosion coating treatment, the surface of the tunnel shield concrete segment is pretreated, including cleaning, grinding and primer coating.

[0026] As a further description of the above technical solution:

[0027] The aggregate in S1 is crushed stone or gravel.

[0028] As a further description of the above technical solution:

[0029] The additive in S1 is a water reducing agent, a retarder or an air entraining agent.

[0030] As a further description of the above technical solution:

[0031] The anti-corrosion coating is a nano silicon dioxide or nano zinc oxide coating.

[0032] As a further description of the above technical solution:

[0033] Polypropylene fiber or carbon fiber is also added into the concrete raw material.

[0034] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0035] In the present invention, firstly, raw materials with corrosion resistance are selected, including cement, aggregate, additives and corrosion inhibitors in a specific ratio. These materials are mixed evenly in the concrete preparation stage to form corrosion-resistant concrete. Then, a mold matching the shape and size of the tunnel shield concrete segment is used to pour the prepared concrete into the mold, and the concrete is vibrated to ensure that it is evenly filled and bubbles are removed. After that, a curing treatment is performed to promote the hardening of the concrete and the effect of the corrosion inhibitor. After the concrete reaches a certain strength, demoulding and trimming are performed, and then one or more layers of corrosion-resistant coatings are coated on the surface of the concrete segment to further enhance its corrosion resistance. Finally, quality inspection is performed to ensure that the product quality meets the design requirements. The production process makes it corrosion-resistant from the original formula. Subsequently, by adding polypropylene fiber and carbon fiber, a mesh structure can be formed inside the concrete to reduce the formation of cracks, thereby reducing the risk of penetration of corrosive media. Finally, nano-composite coating technology is used to prepare a concrete coating containing nano-materials (such as nano-silicon dioxide, nano-zinc oxide), and the nano-composite material is evenly coated on the surface of the concrete segment by mechanical or manual methods to form a dense protective layer. Corrosion protection is carried out in every step from the production formula, production process and external coating, thereby improving the corrosion resistance of the overall structure of the prefabricated segment, avoiding cracks caused by corrosion in the prefabricated segment, and improving the service life and safety performance of the prefabricated segment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 This is a process flow chart for the anti-corrosion manufacturing process of tunnel shield concrete segments. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0042] In the description of the embodiments of the present invention, it should be noted that the terms "upper", "inner", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0043] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] See also Figure 1 The present invention provides a technical solution: a tunnel shield concrete segment anti-corrosion manufacturing process, specifically comprising the following steps:

[0045] S1: Raw material preparation, selecting concrete raw materials with corrosion resistance, the concrete raw materials include cement, aggregate, additives and anti-corrosion agents; can effectively improve the acid and alkali resistance, salt spray resistance and chemical corrosion resistance of concrete.

[0046] S2: concrete preparation, mixing the cement, the aggregate, the additive and the anti-corrosion agent evenly according to a predetermined ratio to form anti-corrosion concrete;

[0047] S3: Mould preparation: prepare corresponding moulds according to the shape and size of the tunnel shield concrete segments and ensure that the mould surface is smooth and flawless;

[0048] S4: Concrete pouring: pouring the prepared anti-corrosion concrete into a mold and fully vibrating it to ensure that the anti-corrosion concrete is evenly filled and bubbles are removed; improving the density and anti-corrosion effect of the concrete.

[0049] S5: curing treatment, curing the poured anti-corrosion concrete to promote the hardening of the concrete and the functioning of the anti-corrosion agent;

[0050] S6: demoulding and finishing, after the anti-corrosion concrete reaches a certain strength, demoulding operation is performed, and the surface of the tunnel shield concrete segment is finished to remove excess concrete and defects;

[0051] S7: Anti-corrosion coating treatment, coating one or more layers of anti-corrosion coating on the surface of the tunnel shield concrete segment; after the coating is cured, necessary post-treatment such as grinding and cleaning is performed to ensure uniformity and adhesion of the coating.

[0052] S8: Quality inspection, quality inspection of the completed tunnel shield concrete segments, including appearance inspection, dimension measurement, corrosion resistance test, etc., to ensure that the product quality meets the design requirements.

[0053] The mass ratios of the cement, the aggregate, the additive and the anticorrosive agent in the concrete raw materials in S2 are 75-80%, 15-20%, 1-2% and 2-5% respectively.

[0054] The anti-corrosion agent in S1 is at least one of an organic silicon, a silicate or an epoxy resin anti-corrosion agent.

[0055] During the concrete pouring process in S4, a high-frequency vibrator is used to vibrate the concrete to improve the density and anti-corrosion effect of the concrete.

[0056] The corrosion resistance test in S8 adopts salt spray test, acid and alkali immersion test or chemical corrosion test method.

[0057] Before the S7 anti-corrosion coating treatment, the surface of the tunnel shield concrete segment is pretreated, including cleaning, grinding and primer coating.

[0058] The aggregate in S1 is crushed stone or gravel.

[0059] The additive in S1 is a water reducing agent, a retarder or an air entraining agent.

[0060] The anti-corrosion coating is a nano silicon dioxide or nano zinc oxide coating.

[0061] Polypropylene fiber or carbon fiber is also added into the concrete raw material.

[0062] Working principle: First, select raw materials with corrosion resistance, including cement, aggregate, additives and corrosion inhibitors in a specific ratio. These materials are mixed evenly during the concrete preparation stage to form corrosion-resistant concrete. Then, use a mold that matches the shape and size of the tunnel shield concrete segment to pour the prepared concrete into the mold, and vibrate to ensure that the concrete is evenly filled and bubbles are removed. After that, perform maintenance treatment to promote the hardening of the concrete and the action of the corrosion inhibitor. After the concrete reaches a certain strength, demould and trim it, and then apply one or more layers of anti-corrosion coating on the surface of the concrete segment to further enhance its corrosion resistance. Finally, quality inspection is performed to ensure that the product quality meets the design requirements. The production process makes it corrosion-resistant from the original formula. Subsequently, by adding polypropylene fiber and carbon fiber, a mesh structure can be formed inside the concrete to reduce the formation of cracks, thereby reducing the risk of penetration of corrosive media. Finally, nano-composite coating technology is used to prepare a concrete coating containing nano-materials (such as nano-silicon dioxide, nano-zinc oxide), and the nano-composite material is evenly coated on the surface of the concrete segment by mechanical or manual methods to form a dense protective layer. Corrosion protection is carried out in every step from the production formula, production process and external coating, thereby improving the corrosion resistance of the overall structure of the prefabricated segment, avoiding cracks caused by corrosion in the prefabricated segment, and improving the service life and safety performance of the prefabricated segment.

[0063] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A tunnel shield concrete segment anti-corrosion manufacturing process, characterized in that: The specific steps include: S1: raw material preparation, selecting concrete raw materials with corrosion resistance, the concrete raw materials including cement, aggregate, additives and anti-corrosion agents; S2: concrete preparation, mixing the cement, the aggregate, the additive and the anti-corrosion agent evenly according to a predetermined ratio to form anti-corrosion concrete; S3: Mould preparation: prepare corresponding moulds according to the shape and size of the tunnel shield concrete segments and ensure that the mould surface is smooth and flawless; S4: Concrete pouring: pouring the prepared anti-corrosion concrete into the mold and fully vibrating it to ensure that the anti-corrosion concrete is evenly filled and bubbles are removed; S5: curing treatment, curing the poured anti-corrosion concrete to promote the hardening of the concrete and the functioning of the anti-corrosion agent; S6: demoulding and finishing, after the anti-corrosion concrete reaches a certain strength, demoulding operation is performed, and the surface of the tunnel shield concrete segment is finished to remove excess concrete and defects; S7: Anti-corrosion coating treatment, coating one or more layers of anti-corrosion coating on the surface of the tunnel shield concrete segment; S8: Quality inspection, quality inspection of the completed tunnel shield concrete segments, including appearance inspection, dimension measurement, corrosion resistance test, etc., to ensure that the product quality meets the design requirements.

2. The anti-corrosion manufacturing process for tunnel shield concrete segments according to claim 1 is characterized in that: The mass ratios of the cement, the aggregate, the additive and the anticorrosive agent in the concrete raw materials in S2 are 75-80%, 15-20%, 1-2% and 2-5% respectively.

3. The anti-corrosion manufacturing process for tunnel shield concrete segments according to claim 2 is characterized in that: The anti-corrosion agent in S1 is at least one of an organic silicon, a silicate or an epoxy resin anti-corrosion agent.

4. The anti-corrosion manufacturing process for tunnel shield concrete segments according to claim 1 is characterized in that: During the concrete pouring process in S4, a high-frequency vibrator is used to vibrate the concrete to improve the density and anti-corrosion effect of the concrete.

5. The anti-corrosion manufacturing process for tunnel shield concrete segments according to claim 1 is characterized in that: The corrosion resistance test in S8 adopts salt spray test, acid and alkali immersion test or chemical corrosion test method.

6. The anti-corrosion manufacturing process for tunnel shield concrete segments according to claim 1 is characterized in that: Before the S7 anti-corrosion coating treatment, the surface of the tunnel shield concrete segment is pretreated, including cleaning, grinding and primer coating.

7. The anti-corrosion manufacturing process for tunnel shield concrete segments according to claim 1 is characterized in that: The aggregate in S1 is crushed stone or gravel.

8. The anti-corrosion manufacturing process for tunnel shield concrete segments according to claim 7 is characterized in that: The additive in S1 is a water reducing agent, a retarder or an air entraining agent.

9. The anti-corrosion manufacturing process for tunnel shield concrete segments according to claim 7, characterized in that: The anti-corrosion coating is a nano silicon dioxide or nano zinc oxide coating.

10. The anti-corrosion manufacturing process for tunnel shield concrete segments according to claim 7, characterized in that: Polypropylene fiber or carbon fiber is also added into the concrete raw material.

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