A patching material, its preparation method and use

Abstract

This application relates to the technical field of rail transit equipment repair, specifically disclosing a repair material, its preparation method, and its application. The repair material disclosed in this application specifically includes the following components: cement, H60 type high-strength non-shrink grout, modified diatomaceous earth, acrylic emulsion, defoamer, thickener, water-repellent agent, film-forming aid, and water. The modified diatomaceous earth is prepared by using a 0.2-0.8 wt% phosphoric acid aqueous solution as a solvent and ethyl cellulose as a modifier at a temperature of 80-100℃, followed by modification of the diatomaceous earth; the weight ratio of ethyl cellulose to diatomaceous earth is (6-8):(1-3). This application also discloses the preparation method of the above-mentioned repair material. Using the repair material disclosed in this application to repair track ventilation ducts can improve the appearance quality of the track top ventilation ducts, and the repaired track top ventilation ducts have good bonding strength, impermeability, water resistance, and aging resistance.

Description

Technical Field

[0001] This application relates to the technical field of rail transit equipment repair, specifically to a repair material, its preparation method, and its application. Background Technology

[0002] In subway station structures, the track-top ventilation duct is responsible for both ventilation and air supply, making it an important component of the subway station structure. Due to the special nature of its location, the track-top ventilation duct is generally not poured simultaneously with the main station structure, especially in stations through which tunnel boring machines (TBMs) need to pass, where the track-top ventilation duct must be poured later.

[0003] In the post-construction method, the construction space for the rail top ventilation duct is small and the cross-section of the rail top ventilation duct is large, which makes it difficult to remove concrete air bubbles and results in a large number of pores. In particular, the pores on the inner bottom surface of the U-shaped component are particularly obvious, resulting in poor appearance quality, easy occurrence of voids, and easy damage to the rail top ventilation duct. Summary of the Invention

[0004] In order to reduce air bubbles and voids in the rail top ventilation duct and improve its appearance quality, this application provides a repair material, its preparation method, and its application.

[0005] In a first aspect, this application provides a repair material, specifically comprising the following components in parts by weight: 100-130 parts cement, 20-30 parts H60 high-strength non-shrink grout, 2-5 parts modified diatomaceous earth, 4-8 parts acrylic emulsion, 0.01-0.08 parts defoamer, 0.02-0.12 parts thickener, 0.004-0.012 parts water repellent, 0.01-0.05 parts film-forming aid, and 40-60 parts water;

[0006] The modified diatomaceous earth is prepared by adding diatomaceous earth to a 0.2-0.8 wt% phosphoric acid aqueous solution as a solvent and ethyl cellulose as a modifier at a temperature of 80-100℃ for 3-5 hours under constant temperature conditions. The reaction solution is then cooled to room temperature, filtered and dried to obtain the modified diatomaceous earth. The weight ratio of ethyl cellulose to diatomaceous earth is (6-8):(1-3).

[0007] This application utilizes a certain concentration of phosphoric acid aqueous solution as a solvent and ethyl cellulose as a modifier to modify diatomaceous earth to prepare modified diatomaceous earth. Then, it is used in combination with cement, high-strength non-shrink grout, acrylic emulsion and other auxiliary components to obtain a repair material. When this repair material is used to repair the rail top ventilation duct, it can improve the appearance quality of the rail top ventilation duct, and the repaired rail top ventilation duct has good bonding strength, impermeability, water resistance and aging resistance.

[0008] Compared to ordinary unmodified diatomaceous earth, this application uses an aqueous solution of phosphoric acid with phosphate functional groups as a solvent and ethyl cellulose, which has adhesive, filling and film-forming effects, as a modifier to modify diatomaceous earth. This reduces the viscosity of the diatomaceous earth structure and reduces the phenomenon of diatomaceous earth aggregation, thereby improving the dispersibility of diatomaceous earth in the repair material system.

[0009] The repair material prepared in this application exhibits strong adhesion to the surface of the concrete to be repaired. After application, it can quickly form a dense curing film on the surface. Furthermore, the modified diatomaceous earth can block the capillary channels of the concrete and high-strength non-shrink grout, isolating their surfaces from the air and thus preventing moisture evaporation, improving the curing effect, and allowing the repair material to utilize its own moisture to complete the hydration process to the maximum extent. Therefore, when the modified diatomaceous earth provided in this application is used to prepare the repair material, it exhibits high bonding strength after repairing the rail top air duct. Through special embedding and interfacial barrier effects, the repaired sample also possesses high impermeability and water resistance.

[0010] The modified diatomaceous earth prepared in this application exhibits good compatibility with cement, high-strength non-shrink grout, acrylic emulsion, and other auxiliary materials. It adjusts the viscosity and system stability of the repair material, ensuring uniform moisture distribution within the grout. The modified diatomaceous earth not only provides greater steric hindrance to the repair material, improving the dispersion performance of each component, but also effectively prevents the long side-chain substances in the repair material from curling, entangled, and agglomerating, thus maintaining good fluidity of the cement. Furthermore, it prevents the repair material from migrating or precipitating over time, thus maintaining its aging resistance and contributing to its long-lasting aging resistance and extended service life.

[0011] Preferably, the concentration of the phosphoric acid aqueous solution is 0.4-0.6 wt%.

[0012] In one specific embodiment, the concentration of the phosphoric acid aqueous solution may be 0.2wt%, 0.4wt%, 0.5wt%, 0.6wt%, or 0.8wt%.

[0013] In some specific embodiments, the concentration of the phosphoric acid aqueous solution may also be 0.2-0.4 wt%, 0.2-0.5 wt%, 0.2-0.6 wt%, 0.4-0.5 wt%, 0.4-0.8 wt%, 0.5-0.6 wt%, 0.5-0.8 wt%, or 0.6-0.8 wt%.

[0014] Experimental analysis shows that by controlling the concentration of the phosphoric acid aqueous solution within the above-mentioned range, this application can significantly improve the structural strength, impermeability, water resistance, and aging resistance of the repaired rail top ventilation duct.

[0015] Preferably, the viscosity of the ethyl cellulose is 8-220 mPa·s.

[0016] Preferably, the viscosity of the ethyl cellulose is 40-100 mPa·s.

[0017] Experimental analysis shows that the use of ethyl cellulose with a viscosity within the above-mentioned range as a modifier in this application can further improve the structural strength, impermeability, water resistance and aging resistance of the repaired rail top air duct.

[0018] Preferably, the diatomaceous earth has a particle size of 100-325 mesh.

[0019] Furthermore, the particle size of the diatomaceous earth is 150-250 mesh.

[0020] In one specific implementation, the particle size of the diatomaceous earth can be 100 mesh, 150 mesh, 200 mesh, 250 mesh, or 325 mesh.

[0021] In some specific implementations, the particle size of the diatomaceous earth can also be 100-150 mesh, 100-200 mesh, 100-250 mesh, 150-200 mesh, 150-325 mesh, 200-250 mesh, 200-325 mesh, or 250-325 mesh.

[0022] Experimental analysis shows that the use of ethyl cellulose within the above-mentioned range as a modifier in this application can further improve the structural strength, impermeability, water resistance and aging resistance of the repaired rail top ventilation duct.

[0023] Preferably, the acrylic emulsion is selected from any one or more of pure acrylic emulsion, silicone acrylic emulsion, and styrene acrylic emulsion.

[0024] The acrylic emulsion added in this application is one or more of pure acrylic emulsion, silicone acrylic emulsion, and styrene acrylic emulsion. Acrylic emulsion has good weather resistance, hydrophobicity and adhesion, which helps to make up for the problem of poor water resistance of cement. At the same time, it can improve the weather resistance of the repair material and further improve its bonding strength with the original concrete.

[0025] Furthermore, the acrylic emulsion is a silicone-acrylic emulsion and a styrene-acrylic emulsion in a weight ratio of (8-12):(0.5-1.5).

[0026] Experimental analysis shows that selecting silicone-acrylic emulsion and styrene-acrylic emulsion within the above weight ratio range as acrylic emulsions in this application can further improve the structural strength, impermeability, water resistance and aging resistance of the repaired rail top air duct.

[0027] Secondly, this application provides a method for preparing the above-mentioned repair material, specifically including the following steps:

[0028] The cement, the high-strength non-shrink grout, and the modified diatomaceous earth are mixed evenly to obtain a dry material;

[0029] The acrylic emulsion and other components are uniformly dispersed in the water to obtain a mixed solution;

[0030] Add the mixed solution to the dry material and stir for 40-80 seconds to obtain the repair material.

[0031] Thirdly, this application provides the application of the above-mentioned repair materials in the repair of rail transit equipment.

[0032] Preferably, the rail transit equipment is a rail-top ventilation duct.

[0033] In summary, the technical solution of this application has the following effects:

[0034] This application utilizes a certain concentration of phosphoric acid aqueous solution as a solvent and ethyl cellulose as a modifier to modify diatomaceous earth to prepare modified diatomaceous earth. Then, it is used in combination with cement, high-strength non-shrink grout, acrylic emulsion and other auxiliary components to obtain a repair material. This repair material can be used to repair rail top ventilation ducts, which can improve the appearance quality of rail top ventilation ducts. The repaired rail top ventilation ducts have good bonding strength, impermeability, water resistance and aging resistance.

[0035] The repair material of this application improves the bond strength between the repair material and the original concrete by using modified diatomaceous earth and improves the water resistance of cement by using acrylic emulsion, thereby obtaining a repair material with fast repair speed, strong adhesion and good water resistance.

[0036] This application provides a repair material through reasonable proportioning and selection of component types. The components in the material work together to ensure good compatibility between the components and improve the anti-aging properties of the repair material, thereby effectively extending the service life of the repaired sample. Attached Figure Description

[0037] Figure 1 This is a bottom view of the rail-top ventilation duct component before repair.

[0038] Figure 2 This is a side view of the rail-top ventilation duct component before repair.

[0039] Figure 3 This is a bottom view of the rail top air duct component after repair using the repair material in Example 15.

[0040] Figure 4 This is a side view of the rail-top air duct component after repair using the repair material in Example 15. Detailed Implementation

[0041] The present application will be further described in detail below with reference to embodiments, comparative examples and performance test results. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0042] The ethyl cellulose and methyl cellulose used in this application were purchased from Shanghai Yuanye Biotechnology Co., Ltd., diatomaceous earth from Lingshou Yangshi Mineral Products Co., Ltd., P.O22.5 ordinary silicate cement from Lingshou Yuantong Mineral Products Trading Co., Ltd., H60 high-strength non-shrink grout from Shandong Lujie New Building Materials Co., Ltd., pure acrylic emulsion (model SD-168), silicone acrylic emulsion (model SD-528) and styrene acrylic emulsion (model S-01) from Jiangsu Shengda New Material Technology Co., Ltd., defoamer (model XWC-0285 powder / T112) from Hefei Xinwancheng Environmental Protection Technology Co., Ltd., thickener (model Rheovis PU 1190) from Chongqing Pingchuan Chemical Co., Ltd., water repellent (model H-1402) from Guangzhou Huitu New Material Co., Ltd., and film-forming aid (model Loxanal MI 6840) from BASF (China) Co., Ltd.

[0043] Preparation Example

[0044] Preparation Example 1

[0045] This preparation example provides a modified diatomaceous earth.

[0046] The method for preparing modified diatomaceous earth in this preparation example is as follows:

[0047] At room temperature, 50g of a 0.5wt% phosphoric acid aqueous solution was added to a three-necked flask, followed by 7g of ethyl cellulose with a viscosity of 40-100mPa·s. The reaction solution was heated to 90±5℃. 2g of diatomaceous earth with a particle size of 200 mesh was added to the reaction solution and the reaction was carried out at a constant temperature for 4h.

[0048] After the reaction was completed, the reaction solution was cooled to room temperature, filtered using a filter membrane with a pore size of 0.22 micrometers, and then dried in an oven at 60°C for 4 hours to obtain modified diatomaceous earth.

[0049] Preparation Examples 2-5

[0050] Preparation Examples 2-5 each provide a modified diatomaceous earth.

[0051] The difference between the above preparation example and preparation example 1 is that the concentration of the phosphoric acid aqueous solution is as shown in Table 1. The preparation methods of the remaining raw materials and modified diatomaceous earth in this preparation example are the same as those in preparation example 1.

[0052] Table 1. Concentration of phosphoric acid aqueous solution in preparation examples 1-5

[0053]

[0054] Preparation Examples 7-10

[0055] Preparation Examples 7-10 each provide a modified diatomaceous earth.

[0056] The difference between the above preparation example and preparation example 1 is that the weight ratio of ethyl cellulose to diatomaceous earth is as shown in Table 2. The preparation methods of the remaining raw materials and modified diatomaceous earth in the above preparation example are the same as those in preparation example 1.

[0057] Table 2. Weight ratio of ethyl cellulose to diatomaceous earth in Preparation Examples 1 and 7-10

[0058]

[0059] Preparation Example 11

[0060] This preparation example provides a modified diatomaceous earth.

[0061] The difference between this preparation example and Preparation Example 1 is that the viscosity of ethyl cellulose is 8-10 mPa·s, while the preparation methods of the remaining raw materials and modified diatomaceous earth in this preparation example are the same as those in Preparation Example 1.

[0062] Preparation Example 12

[0063] This preparation example provides a modified diatomaceous earth.

[0064] The difference between this preparation example and Preparation Example 1 is that the viscosity of ethyl cellulose is 180-220 mPa·s, while the preparation methods of the remaining raw materials and modified diatomaceous earth in this preparation example are the same as those in Preparation Example 1.

[0065] Preparation Example 13

[0066] This preparation example provides a modified diatomaceous earth.

[0067] The difference between this preparation example and preparation example 1 is that diatomaceous earth with a particle size of 100 mesh is used instead of diatomaceous earth with a particle size of 200 mesh. The preparation methods of the remaining raw materials and modified diatomaceous earth in this preparation example are the same as those in preparation example 1.

[0068] Preparation Example 14

[0069] This preparation example provides a modified diatomaceous earth.

[0070] The difference between this preparation example and preparation example 1 is that diatomaceous earth with a particle size of 325 mesh is used instead of diatomaceous earth with a particle size of 200 mesh. The preparation methods of the remaining raw materials and modified diatomaceous earth in this preparation example are the same as those in preparation example 1.

[0071] Preparation Example 15

[0072] This preparation example provides a modified diatomaceous earth.

[0073] The difference between this preparation example and preparation example 1 is that methylcellulose with a viscosity of 350-550 mPa·s is used instead of ethylcellulose with a viscosity of 40-100 mPa·s. The preparation methods of the remaining raw materials and modified diatomaceous earth in this preparation example are the same as those in preparation example 1.

[0074] Example

[0075] Examples 1-10

[0076] Examples 1-10 each provide a repair material.

[0077] The difference in the repair materials in the above embodiments lies in the source of the modified diatomaceous earth, as shown in Table 3.

[0078] The preparation method of the repair material in the above embodiments is as follows:

[0079] (1) Mix 115g of P.O22.5 ordinary silicate cement, 25g of H60 high-strength non-shrink grouting material and 3g of modified diatomaceous earth evenly to obtain dry material;

[0080] (2) Mix 6g of pure acrylic emulsion (model SD-168), 0.04g of defoamer (model XWC-0285 powder / T112), 0.06g of thickener (model Rheovis PU 1190), 0.008g of water repellent (model H-1402), and 0.03g of film-forming aid (model Loxanal MI 6840) with 50g of water to obtain a mixed solution;

[0081] (3) Add the mixed solution to the dry material and stir for 60 seconds to obtain the repair material.

[0082] Table 3 Sources of diatomaceous earth in Examples 1-10

[0083] Example 11

[0084] This embodiment provides a repair material.

[0085] The difference between this embodiment and Embodiment 1 is that the acrylic emulsion is a silicone-acrylic emulsion (model SD-528), and the preparation methods of the remaining raw materials and repair materials in this embodiment are the same as those in Embodiment 1. Example 12

[0086] This embodiment provides a repair material.

[0087] The difference between this embodiment and Example 1 is that the acrylic emulsion is a styrene-acrylic emulsion (model S-01), and the preparation methods of the remaining raw materials and repair materials in this embodiment are the same as those in Example 1. Example 13

[0088] This embodiment provides a repair material.

[0089] The difference between this embodiment and Embodiment 1 is that the acrylic emulsion is a pure acrylic emulsion and a silicone acrylic emulsion with a weight ratio of 8:1. The preparation methods of the remaining raw materials and repair materials in this embodiment are the same as those in Embodiment 1. Example 14

[0090] This embodiment provides a repair material.

[0091] The difference between this embodiment and Embodiment 1 is that the acrylic emulsion is a pure acrylic emulsion and a styrene-acrylic emulsion with a weight ratio of 8:1. The preparation methods of the remaining raw materials and repair materials in this embodiment are the same as those in Embodiment 1. Example 15

[0092] This embodiment provides a repair material.

[0093] The difference between this embodiment and Embodiment 1 is that the acrylic emulsion is a silicone-acrylic emulsion and a styrene-acrylic emulsion with a weight ratio of 8:1. The preparation methods of the remaining raw materials and repair materials in this embodiment are the same as those in Embodiment 1. Example 16

[0094] This embodiment provides a repair material.

[0095] The difference between this embodiment and Example 1 is that the acrylic emulsion is a silicone-acrylic emulsion and a styrene-acrylic emulsion with a weight ratio of 8:1.5. The preparation methods of the remaining raw materials and repair materials in this embodiment are the same as those in Example 1. Example 17

[0096] This embodiment provides a repair material.

[0097] The difference between this embodiment and Embodiment 1 is that the acrylic emulsion is a silicone-acrylic emulsion and a styrene-acrylic emulsion with a weight ratio of 12:0.5. The preparation methods of the remaining raw materials and repair materials in this embodiment are the same as those in Embodiment 1. Example 18

[0098] This embodiment provides a repair material.

[0099] The difference between this embodiment and Example 1 is that the acrylic emulsion is a silicone-acrylic emulsion and a styrene-acrylic emulsion with a weight ratio of 8:2. The preparation methods of the remaining raw materials and repair materials in this embodiment are the same as those in Example 1. Example 19

[0100] This embodiment provides a repair material.

[0101] The difference between this embodiment and Example 1 is that the acrylic emulsion is a silicone-acrylic emulsion and a styrene-acrylic emulsion with a weight ratio of 13:0.5. The preparation methods of the remaining raw materials and repair materials in this embodiment are the same as those in Example 1. Comparative Example Comparative Example 1

[0102] This comparative example provides a repair material.

[0103] The difference between this comparative example and Example 1 is that unmodified diatomaceous earth is used instead of modified diatomaceous earth.

[0104] The preparation method of the repair material in this comparative example is as follows:

[0105] (1) Mix 115g of P.O22.5 ordinary silicate cement, 25g of H60 high-strength non-shrink grouting material and 3g of diatomaceous earth with a particle size of 200 mesh evenly to obtain dry material;

[0106] (2) Mix 6g of pure acrylic emulsion (model SD-168), 0.04g of defoamer (model XWC-0285 powder / T112), 0.06g of thickener (model Rheovis PU 1190), 0.008g of water repellent (model H-1402), and 0.03g of film-forming aid (model Loxanal MI 6840) with 50g of water to obtain a mixed solution;

[0107] (3) Add the mixed solution to the dry material and stir for 60 seconds to obtain the repair material. Comparative Example 2

[0108] This comparative example provides a repair material.

[0109] The preparation method of the repair material in this comparative example is as follows:

[0110] (1) Mix 115g of P.O22.5 ordinary silicate cement, 25g of H60 high-strength non-shrink grout, 3g of diatomaceous earth with a particle size of 200 mesh, 7g of ethyl cellulose with a viscosity of 40-100mPa.s and 0.25g of phosphoric acid evenly to obtain dry material;

[0111] (2) Mix 6g of pure acrylic emulsion (model SD-168), 0.04g of defoamer (model XWC-0285 powder / T112), 0.06g of thickener (model Rheovis PU 1190), 0.008g of water repellent (model H-1402), and 0.03g of film-forming aid (model Loxanal MI 6840) with 50g of water to obtain a mixed solution;

[0112] (3) Add the mixed solution to the dry material and stir for 60 seconds to obtain the repair material.

[0113] Comparative Examples 3-7

[0114] Comparative Examples 3-7 each provide a repair material.

[0115] The difference between the repair materials in the above comparative examples and those in Example 1 is that the source of the modified diatomaceous earth is different, as shown in Table 4.

[0116] Table 4. Sources of diatomite in Comparative Examples 3-7

[0117]

[0118] Performance testing

[0119] The testing method and specific steps are as follows:

[0120] Clean the surface of the rail top ventilation duct component to be repaired, removing laitance, dust, and other debris. Then rinse it with clean water and remove the water.

[0121] The repair materials used in Examples 1-19 and Comparative Examples 1-7 were applied to the bottom surface of the rail top air duct component, smoothed with a trowel, and excess slurry was scraped off. The sample was then cured for 21 days according to the method specified in JG / T 23, and then the following performance tests were performed on the sample.

[0122] During the experiment, H60 high-strength non-shrink grout was used to prepare repair material at a water-to-material ratio of 0.17. The material was then applied to the bottom surface of the rail top ventilation duct component as a blank control group.

[0123] (1) Bond strength and impermeability: The bond strength and impermeability of the samples were tested according to the method specified in GB / T23445 "Polymer Cement Waterproof Coatings";

[0124] (2) Water resistance and aging resistance: The water resistance and aging resistance of the samples were tested according to the method specified in JG 26 "Inorganic Building Coatings for Exterior Walls";

[0125] Water resistance: During the water resistance test, every 100 hours, observe whether the repaired sample shows any adverse phenomena such as blistering, peeling, or cracking. If the adverse phenomena occur within ≤50 hours, the water resistance is rated as Grade 1; if the adverse phenomena occur within ≤100 hours, the water resistance is rated as Grade 2; if the adverse phenomena occur within ≤200 hours, the water resistance is rated as Grade 3; if the adverse phenomena occur within ≤300 hours, the water resistance is rated as Grade 4; and if the adverse phenomena occur within ≤300 hours, the water resistance is rated as Grade 5.

[0126] Aging resistance: During the aging resistance test, every 100 hours, observe whether the repaired sample shows any adverse phenomena such as blistering, peeling, or cracking; if the adverse phenomena occur within ≤100 hours, the aging resistance is rated as Level 1; if the adverse phenomena occur within ≤300 hours after 100 hours, the aging resistance is rated as Level 2; if the adverse phenomena occur within ≤500 hours after 300 hours, the aging resistance is rated as Level 3; if the adverse phenomena occur within ≤800 hours after 500 hours, the aging resistance is rated as Level 4; and if the adverse phenomena occur within ≤800 hours, the aging resistance is rated as Level 5.

[0127] Loss rate of bond strength after aging resistance (80℃, 720h): Place the sample at 80℃ for 720h, test the bond strength of the sample according to the method specified in GB / T23445 "Polymer Cement Waterproof Coating", and calculate the loss rate of bond strength.

[0128] Test results are shown in Table 5.

[0129] Table 5 Performance test results of samples in Examples 1-19 and Comparative Examples 1-7

[0130]

[0131] Based on the test results in Table 5, and by comparing the test results of Examples 1-19 with those of Comparative Examples 1-7, this application utilizes a certain concentration of phosphoric acid aqueous solution as a solvent and ethyl cellulose as a modifier to modify diatomaceous earth to prepare a modified diatomaceous earth. This modified diatomaceous earth is then used in combination with cement, high-strength non-shrink grouting material, acrylic emulsion, and other auxiliary materials to obtain a repair material for repairing rail transit equipment. This material results in a bond strength of ≥1.88MPa and a permeability of ≥0.74MPa for the repaired rail top ventilation duct. Furthermore, the repaired rail top ventilation duct exhibits good water resistance and aging resistance.

[0132] By comparing the test results of Example 1 with those of Comparative Examples 1-2 and 7, it can be seen that in Comparative Examples 1-2, when unmodified diatomaceous earth was used instead of modified diatomaceous earth, the bond strength of the repaired rail top air duct was only 0.78 MPa, the impermeability was 0.54 MPa, the water resistance only reached level three, and the aging resistance only reached level two. Moreover, the bond strength loss rate after the aging test at 80℃ was as high as 10.98%. Comparative Example 7 used phosphoric acid aqueous solution as a solvent and methylcellulose as a modifier to modify diatomaceous earth to obtain modified diatomaceous earth. When diatomaceous earth is added to repair materials, the bond strength of the repaired rail top ventilation duct is only 0.88 MPa, the impermeability is only 0.62 MPa, the water resistance is only level three, and the aging resistance is only level four. Moreover, the bond strength loss rate is as high as 9.68% after an aging resistance test at 80℃. In contrast, this application uses phosphoric acid aqueous solution as a solvent and ethyl cellulose as a modifier to modify diatomaceous earth to obtain modified diatomaceous earth, which, when added to repair materials, can effectively improve the bond strength, impermeability, water resistance, and aging resistance of the rail top ventilation duct.

[0133] Furthermore, by comparing the test results of Examples 1-10 and Comparative Examples 3-6, it was found that in the preparation process of modified diatomaceous earth, the concentration of the phosphoric acid aqueous solution was controlled to be 0.2-0.8 wt%, and the weight ratio of ethyl cellulose to diatomaceous earth was controlled to be (6-8):(1-3), which can further improve the bonding strength, impermeability, water resistance and aging resistance of the rail top ventilation duct.

[0134] By comparing the test results of Example 1 with those of Examples 11-19, compared to using any one of pure acrylic emulsion, silicone acrylic emulsion, or styrene acrylic emulsion as the acrylic emulsion, or using pure acrylic emulsion and silicone acrylic emulsion as the acrylic emulsion, or using pure acrylic emulsion and styrene acrylic emulsion as the acrylic emulsion, this application selects silicone acrylic emulsion and styrene acrylic emulsion as the acrylic emulsion, which can further improve the bonding strength, impermeability, water resistance, and aging resistance of the rail top ventilation duct. Furthermore, this application controls the weight ratio of silicone acrylic emulsion to styrene acrylic emulsion within the range of (8-12):(0.5-1.5).

[0135] (3) Surface observation: Observe the appearance of the bottom and sides of the rail top air duct component before repair; after repair using Example 15, observe the appearance of the bottom and sides of the rail top air duct component after repair.

[0136] Test results: such as Figure 1-4 As shown; where, Figure 1 This is a bottom view of the rail-top ventilation duct components before repair. Figure 2 This is a side view of the rail-top ventilation duct components before repair. Figure 3 This is a bottom view of the repaired top air duct component in Example 15. Figure 4 This is a side view of the repaired top air duct component in Example 15.

[0137] Depend on Figure 1-4 As can be seen from the appearance drawings, the rail top air duct had defects such as air holes before repair. The rail top air duct component was repaired using the repair material of this application. The surface of the repaired sample had no defects such as air holes, bulging, peeling, or cracks, indicating that the repair material provided by this application can be used to repair the rail top air duct and improve the appearance quality of the rail top air duct.

[0138] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A repair material, characterized in that, Specifically, it includes the following components by weight: 100-130 parts cement, 20-30 parts H60 high-strength non-shrink grout, 2-5 parts modified diatomaceous earth, 4-8 parts acrylic emulsion, 0.01-0.08 parts defoamer, 0.02-0.12 parts thickener, 0.004-0.012 parts water repellent, 0.01-0.05 parts film-forming aid, and 40-60 parts water; The modified diatomaceous earth is prepared by adding diatomaceous earth to a 0.2-0.8 wt% phosphoric acid aqueous solution as a solvent and ethyl cellulose as a modifier at a temperature of 80-100℃ for 3-5 hours under constant temperature conditions. The reaction solution is then cooled to room temperature, filtered and dried to obtain the modified diatomaceous earth. The weight ratio of ethyl cellulose to diatomaceous earth is (6-8):(1-3).

2. The repair material according to claim 1, characterized in that, The concentration of the phosphoric acid aqueous solution is 0.2-0.5 wt%.

3. The repair material according to claim 1, characterized in that, The viscosity of the ethyl cellulose is 8-220 mPa·s.

4. The repair material according to claim 3, characterized in that, The viscosity of the ethyl cellulose is 40-100 mPa·s.

5. The repair material according to claim 1, characterized in that, The diatomaceous earth has a particle size of 100-325 mesh.

6. The repair material according to claim 1, characterized in that, The acrylic emulsion is selected from any one or more of pure acrylic emulsion, silicone acrylic emulsion, and styrene acrylic emulsion.

7. The repair material according to claim 1, characterized in that, The acrylic emulsion is a silicone-acrylic emulsion and a styrene-acrylic emulsion in a weight ratio of (8-12):(0.5-1.5).

8. The method for preparing the repair material according to any one of claims 1-7, characterized in that, Specifically, the following steps are included: The cement, the high-strength non-shrink grout, and the modified diatomaceous earth are mixed evenly to obtain a dry material; The acrylic emulsion and other components are uniformly dispersed in the water to obtain a mixed solution; Add the mixed solution to the dry material and stir for 40-80 seconds to obtain the repair material.

9. The application of the repair material as described in any one of claims 1-7 in the repair of rail transit equipment.

10. The application of the repair material according to claim 9 in the repair of rail transit equipment, wherein the rail transit equipment is a rail-top ventilation duct.

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