Anti-permeation waterproof repair material for high-speed rail non-ballasted track plate pouring hole and application thereof

Abstract

The application discloses a kind of anti-permeation waterproof repair materials for high-speed rail non-ballasted track slab perfusion hole and application thereof, it is related to high-speed rail track construction technical field;The material includes cement 400-450 parts by mass, fine aggregate 350-400 parts, expansion component 20-40 parts, active admixture 50-100 parts, dispersible latex powder 20-50 parts, waterproof agent 2-5 parts, thixotropic agent 1-3 parts, polyvinyl alcohol fiber 1-2 parts, thickening agent 0.5-1 part;Waterproof agent is first mixed with ethanol aqueous solution, polydimethylsiloxane is obtained to obtain mixed solution;Polyvinyl alcohol aqueous solution and mixed solution are mixed to obtain composite dispersion, dried, cooled, ground into powder to be made.The repair material provided by the application has good waterproof and anti-permeation performance, mechanical properties, workability and alkali resistance.The material is used to repair high-speed rail non-ballasted track slab perfusion hole, and the material does not crack along the perfusion hole wall, the whole is not offset upward, and the track slab is not separated from the joint and other disease problems.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-speed rail track construction, in particular to a water-proof and anti-permeation repair material for the pouring hole of a high-speed rail slab track and its application. BACKGROUND

[0002] The slab track is a form of high-speed railway track structure, which has good stability, smoothness and less maintenance, and is one of the main structure forms of high-speed railway in China. At present, the slab track structure in China is divided into three types of CRTSI, CRTSII and CRTSIII, the first two of which are introduced from abroad, and the latter is a new type of track structure with independent intellectual property rights in China, which is different from the first two in structure design and material composition. The biggest difference in material is that the adjustment layer material of the CRTSIII slab track structure is self-compacting concrete, not the cement emulsified asphalt mortar of the first two. The self-compacting concrete is initially applied to the slab track in China in small scale in the Pan-Ying passenger dedicated line, Wuhan-Xianning railway of Wuhan urban circle and other lines. The China Railway Corporation approved the use of CRTSIII slab track structure in Zhengzhou-Xuzhou high-speed railway, and the CRTSIII slab track complete technology needs to be discussed and optimized. The CRTSIII slab track structure has been widely used in high-speed railway construction in China, such as Beijing-Shenyang railway, Gan-Deep railway, Hu-Hang railway and Lai-Rong railway.

[0003] At present, the track part of the CRTSIII ballastless track of high-speed railway in China mainly consists of rails, fasteners, sleepers, prefabricated track slabs, self-compacting concrete filling layers, base plates (bridge and tunnel parts) and supporting layers (roadbed parts). The lower structure of the ballastless track consists of inter-line sealing layer, shoulder sealing layer and roadbed. The self-compacting concrete is poured between the base plate and the track slab. After the installation and fine adjustment of the track slab are completed, the self-compacting concrete filling layer is poured in the gap below the track slab to make the track slab, self-compacting concrete filling layer and base plate structure tightly combined to form a whole. The self-compacting concrete is poured through the pouring hole in the center of the track slab until it is level with the surface of the track slab. However, since no waterproof coating is applied to the entire track slab surface during track construction, the top of the grouting material in the pouring hole absorbs too much water during the repeated running of the train and the accumulation of time, and the adhesion between the existing grouting material and the roadbed plate and the base layer is poor, which easily causes the loosening of the grouting material in the pouring hole, the cracks between the track slab and the pouring hole, and even the upward deviation of the grouting material from the pouring hole. The self-waterproofing property is also poor, and the cracks cause the seepage and corrosion of the steel bars in the pouring hole. When the grouting material in the pouring hole is repaired, the repair material and repair method cannot effectively solve the above problems, and the repair quality cannot be guaranteed. SUMMARY

[0004] In view of the above prior art deficiencies, the present application provides a waterproof repair material for high-speed rail non-ballasted track slab pouring holes and its application, which significantly improves the waterproof and impermeable performance of the waterproof repair material by using a special waterproof agent.

[0005] The waterproof repair material for high-speed rail non-ballasted track slab pouring holes comprises, by mass fraction, cement 400-450 parts, fine aggregate 350-400 parts, expansion component 20-40 parts, active admixture 50-100 parts, dispersible latex powder 20-50 parts, waterproof agent 2-5 parts, thixotropic agent 1-3 parts, polyvinyl alcohol fiber 1-2 parts, and thickening agent 0.5-1 part.

[0006] The preparation method of the waterproof agent is as follows:

[0007] A polyvinyl alcohol aqueous solution is prepared using polyvinyl alcohol; nano-silicon dioxide is uniformly mixed with an ethanol aqueous solution, and a polydimethylsiloxane is added to obtain a mixed solution;

[0008] The polyvinyl alcohol aqueous solution and the mixed solution are mixed and stirred to obtain a ternary dispersion, which is dried, cooled, and ground into a powder to obtain the waterproof agent finished product.

[0009] The mass ratio of the polyvinyl alcohol, nano-silicon dioxide, and polydimethylsiloxane is (2-4):(2-4):(85-100).

[0010] Preferably, the mass ratio of the polyvinyl alcohol, nano-silicon dioxide, and polydimethylsiloxane is 3.85:3.75:100.

[0011] More preferably, the mass fraction of the polyvinyl alcohol aqueous solution is 5%; and the mass ratio of the nano-silicon dioxide to the ethanol aqueous solution is 1:3.

[0012] Preferably, in the preparation method of the waterproof agent, the mixing and stirring method for preparing the composite dispersion is 1000-2000 r / min, and the stirring time is 40-80 min.

[0013] Preferably, in the preparation method of the waterproof agent, the drying method is 40-80℃ drying for 8-12 h.

[0014] Most preferably, the drying method is 50℃ drying for 10 h.

[0015] Preferably, the fineness of the waterproof agent is 300-350 nm.

[0016] The conventional waterproof material mainly is a surface layer physical waterproof, prevents the invasion of outside water in a short time, but the durability is poor, and the surface layer waterproof is invalid after a long time, and outside water still invades to cause damage to the structure. If the conventional waterproof material is used to repair the high-speed rail ballastless track slab pouring hole, since the waterproof coating is not applied on the whole surface during construction, and the conventional waterproof material has poor adhesion with the pouring hole material and is not waterproof, after accumulation, the top of the pouring hole is also prone to cracking of the waterproof material due to excessive water accumulation and absorption, and the whole material is upwardly moved relative to the track slab.

[0017] The present application provides an anti-permeation waterproof repair material which can effectively solve the above-mentioned cracking and water seepage problems and is specially used for repairing the pouring hole of the high-speed rail ballastless track slab. The innovative improvement of the raw material waterproof agent used is one of the key technologies. The anti-permeation waterproof repair material of the present application adds the waterproof agent prepared by the above-mentioned method to the existing conventional raw materials, so that the material has better waterproof and anti-permeation performance.

[0018] The particle size of the waterproof agent particles is extremely small, and the waterproof agent can penetrate in the material interior along with water in the cement slurry and be distributed in the pore solution. The interfacial tension of the polydimethylsiloxane in the waterproof agent is small, which can reduce the resistance encountered in the penetration process, ensure uniform distribution of the waterproof agent in the material interior, and has excellent hydrophobic effect, which can improve the waterproof performance of the material in a macroscopic way. The polyvinyl alcohol can partially wrap the active substance nano-silicon dioxide, and form a water-soluble film on the surface of the nano-silicon dioxide, which cooperates with the hydrophobic effect of the polydimethylsiloxane to prevent water from reacting with the nano-silicon dioxide.

[0019] With the continuous progress of the hydration reaction, the free water in the pores of the concrete gradually decreases until it is almost dry, and at the same time, the polyvinyl alcohol on the surface of the nano-silicon dioxide gradually hydrolyzes, and the waterproof agent enters the "dormant" state. When the repair material is affected by the external environment and micro-cracks are generated, water will enter the structure interior along the micro-cracks, at this time, the waterproof agent is activated again, and reacts with the free lime and oxides in the capillary pores under the action of water to generate water-insoluble dendritic crystals, so as to block the water from all directions, and play a water-blocking and waterproof role.

[0020] In the above-mentioned anti-permeation waterproof repair material, the cement, fine aggregate, expansion component, active admixture, dispersible latex powder, thixotropic agent, polyvinyl alcohol fiber and thickening agent used can all be selected from the commonly used raw materials in the industry.

[0021] In order to further promote the rapid hydration of the anti-permeation waterproof repair material and improve the mechanical strength, and ensure that the construction is completed during the skylight period (when the train stops running), the cement can be selected from 2-3 kinds of P.O 42.5 ordinary portland cement, low-alkali sulphoaluminate cement and high-alumina cement.

[0022] Optionally, the fine aggregate is conventional river sand, machine-made sand, quartz sand, etc. Further, the fine aggregate selects high-calcium machine-made sand (40-140 mesh), and the grading ratio is 3:3:4 in mass ratio of 40-70 mesh, 70-90 mesh, and 90-140 mesh.

[0023] In order to compensate for the dry shrinkage of the anti-permeation waterproof repair material generated in the rapid hydration process and reduce the risk of cracking, an expansion component needs to be added.

[0024] Optionally, the expansion component is two to three of desulfurized gypsum, anhydrite, and alunite. These expansion component raw materials can absorb part of Ca(OH)2 to form secondary hydration, and generate ettringite C3A·3CaSO4·32H2O and CaO·Al2O3·6H2O crystals with cement hydration products. The ettringite generated in the plastic stage of material hydration can fill the gaps of hydration dry shrinkage, and generate more crystal water to reduce the volume shrinkage generated by the evaporation of free water; the structure is more compact, the anti-permeation effect is better, and has the effects of micro-aggregate, micro-crystal nucleus, and volcanic ash, which greatly improves the physical properties of the structure in different forms.

[0025] Further optionally, the expansion component selects desulfurized gypsum and anhydrite.

[0026] The active admixture is compounded by an alkali activator and an admixture. The selected active admixture has a 1d activity index > 125% and a 28d activity index > 100%, which guarantees the later strength of the anti-permeation waterproof repair material and improves the corrosion resistance of the material.

[0027] In order to achieve the above requirements, the alkali activator is one or both of sodium silicate and calcium formate.

[0028] Optionally, the admixture is compounded by two of calcined metakaolin, microsilica, and nanosilica.

[0029] Further optionally, the compounding ratio of the alkali activator and the admixture is (0.01-0.2):1.

[0030] The purpose of selecting the thickening agent and the dispersible latex powder is to increase the cohesive force of the material as a whole and guarantee the bonding performance with the track plate foundation structure. When the dry powder of the anti-permeation waterproof repair material is added to water and stirred, the latex powder particles are dispersed into water under the action of the hydrophilic protective colloid and mechanical shear force, which plays a lubricating role during construction, and the subsequent viscosity improves the cohesive force of the material as a whole, thereby improving the workability. In an alkaline environment, the polyvinyl alcohol in the dispersible latex powder is saponified to form a network of protective films on the surface of the colloid, which also improves the alkali resistance, waterproofness, and durability of the structure, etc.

[0031] The thixotropic agent and thickening agent are added to play a synergistic effect with the dispersible latex powder, improve the water retention and consistency of the slurry, and greatly optimize the workability and construction performance during the maintenance construction of the high-iron non-ballasted track plate pouring hole.

[0032] Optionally, the thickening agent is one or both of hydroxypropyl methyl cellulose ether (HPMC) and hydroxyethyl cellulose ether (HEC).

[0033] Further optionally, the thickening agent is a combination of hydroxypropyl methyl cellulose ether and hydroxyethyl cellulose ether, and the mass ratio is 1:0.1.

[0034] Optionally, the dispersible latex powder is Wacker 5010 glue powder.

[0035] The polyvinyl alcohol fiber has a length of 6 mm and a diameter of 13 μm, is easy to disperse, and can increase the toughness and corrosion resistance of the anti-seepage waterproof maintenance material.

[0036] Optionally, the thixotropic agent is imported 602 type dry-mixed mortar special thixotropic agent, and the other component is a self-prepared waterproof agent.

[0037] Optionally, in the preparation method of the waterproof agent, the composite dispersion is dried at 50-105°C for 8-12h to obtain a block. Generally, the temperature during drying should not be too high. If it exceeds 105°C, the organic matter will volatilize; if the temperature is too low, the drying time needs to be lengthened, and the drying time can be appropriately shortened when the temperature is high.

[0038] Preferably, the anti-seepage waterproof maintenance material provided by the application includes cement 450 parts, fine aggregate 400 parts, expansion component 40 parts, active admixture 90 parts, dispersible latex powder 20 parts, waterproof agent 2 parts, thixotropic agent 3 parts, polyvinyl alcohol fiber 1 part, and thickening agent 0.5 part by mass fraction.

[0039] A maintenance construction method for a high-iron non-ballasted track plate pouring hole, which uniformly mixes the above anti-seepage waterproof maintenance material, adds water to stir uniformly to form a mixture at a water-material ratio of 0.06-0.08, and is used for maintenance pouring of the high-iron non-ballasted track plate pouring hole.

[0040] Preferably, the maintenance construction method for the high-iron non-ballasted track plate pouring hole further includes the steps of: chiseling and cleaning the damaged loose concrete, aggregate particles, and residual sundries around the pouring hole to be maintained and the periphery thereof;

[0041] Drilling a hole in the bottom of the pouring hole to be maintained and vertically implanting a first steel bar; the upper part of the first steel bar is horizontally bent, and the top surface after bending is higher than the bottom surface of the pouring hole to be maintained; the upper part of the first steel bar is horizontally welded with a second steel bar; pouring the mixture into the pouring hole to be maintained, so that the top of the mixture is higher than the surface of the track plate, curing and solidifying to complete the maintenance.

[0042] More preferably, the implantation depth of the first steel bar is 120-200mm, the height difference between the top surface of the first steel bar after bending and the hole bottom surface of the to-be-repaired cast-in-place hole is 35-55mm; the top of the mixture is higher than the surface of the track slab by no more than 10mm.

[0043] Compared with the prior art, the application has the advantages that the application provides an anti-seepage waterproof repair material for a high-speed rail ballastless track slab cast-in-place hole and a repair use method. The material is used to select a special waterproof agent, so that the waterproof and anti-seepage performance of the anti-seepage waterproof repair material is significantly improved; by adding active admixture, the mechanical properties and corrosion resistance of the material are significantly improved; by adding thickening agent and dispersible latex powder, the workability and alkali resistance of the material during construction are improved. After the material is used to repair the high-speed rail ballastless track slab cast-in-place hole, the material will not crack along the wall of the cast-in-place hole, and the whole will not be offset upward, and other disease problems will not occur. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 Photos of original disease problems of the existing ballastless track cast-in-place hole material;

[0045] Figure 2 Photos after repair using the existing cast-in-place hole material and photos after running for 3 months;

[0046] Figure 3 Photos after repair using the repair material of the embodiment 1 of the application and photos after running for 3 months;

[0047] Figure 4 A cross-sectional view of the treatment in the cast-in-place hole using the repair construction method of the application. DETAILED DESCRIPTION

[0048] The technical solutions of the application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0049] The cement can be selected from cement varieties commonly used in the building material industry, such as P.O 42.5 ordinary portland cement. In order to improve the hydration rate and mechanical strength of the anti-seepage waterproof repair material, the cement can also be selected from low-alkali sulphoaluminate cement, high-alumina cement, or two or three of the three kinds of cement.

[0050] In order to facilitate comparison of data, the cement of the following examples and comparative examples is selected from P.O 42.5 ordinary portland cement (purchased from Hubei Conch Cement) and sulphoaluminate cement (purchased from Tangshan Polar Bear Cement).

[0051] The fine aggregate can be conventional river sand, machine-made sand, quartz sand, etc. in the building material industry.

[0052] In order to facilitate comparison of data, the fine aggregate of the following examples and comparative examples is selected as high-calcium machine-made sand, and the gradation is 40-70 mesh, 70-90 mesh and 90-140 mesh, and the mass ratio is 3:3:4.

[0053] In the present application, in order to compensate for the dry shrinkage generated in the rapid hydration process of the impermeability waterproof repair material and reduce the risk of cracking, an expansion component needs to be added. The expansion component selects materials commonly used in the building material industry, such as calcium oxide, magnesium oxide, etc.

[0054] In order to facilitate comparison of data, the expansion component of the following examples and comparative examples is selected as desulfurized gypsum and anhydrite, and the compounding ratio is 1:0.5, which is purchased from Hubei Kuneng Company.

[0055] The active admixture is a commonly used raw material in the building material industry, such as an alkali activator selected from sodium silicate, calcium formate, etc., and an admixture selected from calcined metakaolin, microsilica, nano-silicon dioxide, etc. In the present application, the active admixture functions to improve the hydration reaction degree and later strength of the impermeability waterproof repair material; the 1d activity index is greater than 125%, and the 28d activity index is greater than 100%.

[0056] Optionally, the compounding mass ratio of the alkali activator and the admixture in the active admixture is (0.01-0.2):1.

[0057] The thickening agent and the dispersible latex powder are commonly used raw materials in the building material industry. In the present application, the purpose of adding the thickening agent and the dispersible latex powder is to increase the cohesive force of the whole material and ensure the bonding performance with the track plate basic structure; under the action of the hydrophilic protective colloid and mechanical shear force, the dispersible latex powder particles are dispersed into water, which plays a lubricating role during construction and improves the workability. The dispersible latex powder can also form a network protective film on the surface of the colloid, which improves the alkali resistance, waterproofness and durability. Therefore, as long as the thickening agent and the dispersible latex powder can play the above-mentioned roles, they can be used in the present application.

[0058] In order to facilitate comparison of data, the dispersible latex powder of the following examples and comparative examples is selected as Wacker 5010 latex powder, and the thickening agent is selected as a mixture of hydroxypropyl methylcellulose ether and hydroxyethyl cellulose ether in a compounding ratio of 1:0.1.

[0059] The function of the thixotropic agent is also to ensure the workability during construction.

[0060] In order to facilitate comparison of data, the thixotropic agent of the following examples and comparative examples is selected as imported 602 type dry-mixed mortar special thixotropic agent

[0061] In the present application, the polyvinyl alcohol fiber is selected to increase the toughness and strength of the material, and has certain corrosion resistance.

[0062] For the convenience of comparing data, the following examples and comparative examples, if not specified, the parameters of polyvinyl alcohol fiber are 6mm in length and 13μm in diameter

[0063] It should be noted that in the following examples and comparative examples, if not specially specified, the waterproof agent is prepared by the following method:

[0064] Prepare a 5% polyvinyl alcohol aqueous solution: slowly add the polyvinyl alcohol powder into water while continuously stirring. If the dissolution is not complete, heating treatment can be performed, generally ensuring the temperature below 60℃;

[0065] Mix the nanosilica (2000 mesh) and 75% ethanol aqueous solution to stir uniformly, then add the polydimethylsiloxane to stir uniformly to obtain a mixed solution;

[0066] Mix the polyvinyl alcohol aqueous solution and the mixed solution to stir (1500r / min, stirring time 60min or so) to obtain a ternary dispersion, dry at 50℃ for 10h to obtain a block, cool, and grind into a powder to obtain the finished waterproof agent with a fineness of 300μm-350μm.

[0067] It should be noted that the anti-permeation waterproof repair material provided in the following examples and comparative examples, if not specially specified, is used as Figure 1 indicated, and the use method (i.e. anti-permeation waterproof repair of high-iron ballastless track slab pouring hole) is specifically as follows:

[0068] Pre-mix the anti-permeation waterproof repair material in a compulsory mixer for 5-6min to prepare a dry mixture; it can be directly used or can be packed in kraft paper bags for later use;

[0069] At the construction site, mix the dry mixture and water with a water-material ratio of 0.08 using a handheld mixer for 2-3min to obtain a mixture, which is ready for use;

[0070] At the same time of preparing the mixture, remove and clean the damaged loose concrete, aggregate particles and residual impurities inside and around the pouring hole to be repaired; the removal depth is not less than 100mm, so that the concrete surface to be repaired is fully exposed, and a vacuum cleaner is used to clean the debris, dust and other impurities in the damaged area

[0071] After the surface is cleaned, drill holes in the concrete to be repaired in the pouring hole (or observation hole) and implant steel bars; the steel bars are L-shaped steel bars with a diameter of 8mm (such as Figure 1The depth of the embedded steel bars is greater than or equal to 120 mm, the height of the top surface of the steel bars from the top surface of the track slab is not less than 35 mm, and a steel bar with a diameter of 8 mm and a length of 170 mm is vertically welded on the upper part of the embedded steel bar;

[0072] Finally, the mixture is poured into the drilled three-type pouring hole (or observation hole) to repair, and after the pouring is completed, the top of the mixture is higher than the surface of the track slab by not more than 10 mm. Figure 2

[0073] Example 1

[0074] The anti-seepage waterproof repair material provided in the example comprises, by mass fraction, cement (P.O 42.5 ordinary portland cement and sulphoaluminate cement in a mass ratio of 1:4) 450 parts, fine aggregate 400 parts, expansion component 40 parts, active admixture 90 parts, dispersible latex powder 20 parts, waterproof agent 2 parts, thixotropic agent 3 parts, polyvinyl alcohol fiber 1 part, and thickening agent 0.5 part.

[0075] The active admixture provided in the example is compounded from sodium silicate and metakaolin in a mass ratio of 0.2:1, and has a 1d activity index greater than 125% and a 28d activity index greater than 100%.

[0076] The waterproof agent used in the example is prepared by the following method:

[0077] (1) 5% polyvinyl alcohol aqueous solution is prepared: polyvinyl alcohol powder is slowly added to water while continuously stirring. If the dissolution is not complete, heating treatment is needed, and the temperature is generally ensured to be below 60°C;

[0078] Nano-silicon dioxide (2000 mesh) and 75% ethanol aqueous solution are mixed in a mass ratio of 1:3 and stirred uniformly, and then polydimethylsiloxane is added and stirred uniformly to obtain a mixed solution; the mass ratio of the total mass of nano-silicon dioxide and the ethanol aqueous solution to the mass of polydimethylsiloxane is 3:20.

[0079] (2) The polyvinyl alcohol aqueous solution and the mixed solution (mass ratio 2:3) are mixed and stirred (1500 r / min, stirring time about 60 min) to obtain a ternary dispersion, which is dried at 50°C for 10 h to obtain a block, which is cooled and ground into powder to obtain the finished waterproof agent with a fineness of 300 μm-350 μm.

[0080] By conversion, the mass ratio of the polyvinyl alcohol powder, nano-silicon dioxide and polydimethylsiloxane is about 3.5:3.75:100.

[0081] Example 2

[0082] ​Compared to Example 1, the waterproofing repair material provided in this example comprises, by weight, 400 parts cement (P.O42.5 ordinary Portland cement and sulfoaluminate cement in a 1:1 ratio), 350 parts fine aggregate, 20 parts expansion component, 100 parts active admixture, 50 parts dispersible latex powder, 5 parts waterproofing agent, 1 part thixotropic agent, 2 parts polyvinyl alcohol fiber, and 1 part thickener. The cement used is P.O42.5 ordinary Portland cement and sulfoaluminate cement in a 1:1 ratio.

[0083] In this embodiment, the waterproofing agent used has a mass ratio of nano-silica (2000 mesh) to 75% ethanol aqueous solution of 1:3; the total mass of nano-silica and ethanol aqueous solution is in a mass ratio of 16:100 to polydimethylsiloxane; and the mass ratio of the polyvinyl alcohol aqueous solution to the mixture is 40:60. After conversion, the mass ratio of polyvinyl alcohol powder, nano-silica, and polydimethylsiloxane is approximately 4:3.87:100.

[0084] Example 3

[0085] Compared to Example 1, the waterproofing repair material provided in this example comprises, by weight, 400 parts cement (P.O42.5 ordinary Portland cement and sulfoaluminate cement in a mass ratio of 3:7), 350 parts fine aggregate, 20 parts expansion component, 100 parts active admixture, 50 parts dispersible latex powder, 5 parts waterproofing agent, 1 part thixotropic agent, 2 parts polyvinyl alcohol fiber, and 1 part thickener. The mass ratio of PO 42.5 ordinary Portland cement and sulfoaluminate cement used in this example is 1:1.

[0086] In this embodiment, the waterproofing agent used has a mass ratio of nano-silica (2000 mesh) to 75% ethanol aqueous solution of 1:4. The total mass of nano-silica and ethanol aqueous solution is in a mass ratio of 15:100 to polydimethylsiloxane; the mass ratio of the polyvinyl alcohol aqueous solution and the mixture is 40:60. Therefore, the mass ratio of polyvinyl alcohol powder, nano-silica, and polydimethylsiloxane is approximately 3:3:100.

[0087] Example 4

[0088] Compared with Example 1, the waterproofing agent in the repair materials provided in this example is 3.5 parts.

[0089] Example 5

[0090] Compared with Example 1, the waterproofing agent in the repair materials provided in this example is 4.5 parts.

[0091] Comparative Example 1

[0092] The anti-seepage waterproof repair material provided by the present comparative example has 0 parts of waterproof agent compared with Example 1. That is, no waterproof agent is used in the anti-seepage waterproof repair material of the present comparative example.

[0093] Comparative Example 2

[0094] The anti-seepage waterproof repair material provided by the present comparative example has 3 parts of conventional silicone waterproof agent (sodium methylsiliconate) as the waterproof agent compared with Example 1.

[0095] Comparative Example 3

[0096] The anti-seepage waterproof repair material provided by the present comparative example has 60 parts of dispersible latex powder compared with Example 1.

[0097] Comparative Example 4

[0098] The anti-seepage waterproof repair material provided by the present comparative example has 0 parts of dispersible latex powder compared with Example 1. That is, no dispersible latex powder is added to the anti-seepage waterproof repair material of the present comparative example.

[0099] Test Example 1: Performance test of anti-seepage waterproof repair material

[0100] The anti-seepage waterproof repair materials prepared in the above examples and comparative examples are stirred uniformly with water at a water-material ratio of 0.06-0.08 to form mixtures, and then mortar test pieces are respectively prepared according to GB / T 17671-2021 “Cement mortar strength test method (ISO method)” and JGJ / T 70-2009 “Building mortar basic performance test method standard”, and the setting time, compressive strength, bonding strength, 28d impermeability pressure and water absorption rate are measured. The results are shown in Table 1 below.

[0101] Table 1: Performance test results of anti-seepage waterproof repair material

[0102]

[0103] As can be seen from Table 1, the mortar test pieces prepared using the anti-seepage waterproof repair materials of Examples 1-3 have better mechanical properties, bonding properties and impermeability, and low water absorption rate (i.e., better waterproof effect).

[0104] Compared with not using any waterproof agent (Comparative Example 1) and using a commercially available conventional silicone waterproof agent (Comparative Example 2), using the special waterproof agent provided by the present application significantly improves the anti-seepage waterproof performance of the repair material, and has little effect on the mechanical strength of the material. As can be seen from Comparative Examples 1, 4 and 5, with the increase of the amount of waterproof agent, the waterproof and anti-seepage performance gradually becomes better, but the compressive strength and the like will decrease.

[0105] Compared with the case without using any dispersible latex powder (comparative example 4), the dispersible latex powder used in the present application can significantly enhance the bonding ability of the repair material to the track slab matrix. With the increase of the amount of dispersible latex powder, the bonding strength decreases and the compressive strength increases. When an excessive amount of dispersible latex powder is used (comparative example 3), the decrease in bonding strength is more obvious, which cannot meet the construction requirements.

[0106] Test example 2: comparison of field pouring effect of anti-permeation waterproof repair material

[0107] Taking the existing pouring hole material as an example, the CRTS III type slab track slab pouring hole (or observation hole) concrete of a certain mileage section range on the uplink and downlink of the ZFZQ-4 section of the Zheng-Fu railway in Henan province has the disease of protruding from the joint, and the pouring hole material will show cracking, upward displacement, and obvious joint separation from the track slab (as shown in Figure 1 ). Many existing pouring hole materials have poor adhesion and are not waterproof. Since the construction process does not coat the entire track slab surface with a waterproof coating, the top of the pouring hole absorbs too much water over time, resulting in displacement and upward deviation of the pouring hole after maintenance, which cannot guarantee the maintenance quality, and the repair using conventional methods is as shown in Figure 2 . Figure 2 The left and right photos in the middle are the photos of the field pouring hole after construction and 3 months after construction, respectively.

[0108] The anti-permeation waterproof repair material provided in the above examples and comparative examples is used in this test example to test the repair construction results of the high-speed rail track slab pouring hole. The use method (i.e., the anti-permeation waterproof repair of the high-speed rail track slab pouring hole) is as follows:

[0109] The anti-permeation waterproof repair material is premixed in a compulsory mixer for 5-6 min to form dry mixture; it can be used directly or packed in kraft paper bags for later use;

[0110] The dry mixture and water are mixed in a hand-held mixer at a water-material ratio of 0.08 to form a mixture, which is ready for use;

[0111] At the same time of preparing the mixture, the damaged loose concrete, aggregate particles and residual debris around the interior and periphery of the pouring hole to be repaired are chiseled and cleaned; the chiseling depth is not less than 100 mm, so that the concrete surface to be repaired is fully exposed, and a vacuum cleaner is used to clean the debris, dust and other impurities in the damaged area;

[0112] As shown in Figure 3 , after the surface is cleaned, a first steel bar is implanted in the pouring hole (or observation hole) to be repaired by drilling a hole; the first steel bar is an L-shaped steel bar with a diameter of 8 mm (as shown in Figure 1The first steel bar is vertically welded on the upper part of the first steel bar, and the second steel bar has a diameter of 8 mm and a length of 170 mm;

[0113] Finally, the mixture is poured into the drilled three-type pouring hole (or observation hole) to repair, and after the pouring is completed, the surface of the pouring mixture is polished to be flush with the surface of the track slab, as shown in FIG. 6. Figure 3 The mixture is shaped like a mushroom head to avoid water seepage, and the top of the mixture is higher than the surface of the track slab by not more than 10 mm. Figure 3 In the above embodiment, the left photo is a field state photo of the poured mixture after the construction is completed and the mixture is shaped, and the right photo is a field effect photo after the construction is completed for 3 months.

[0114] The above embodiment describes the implementation of the present application in detail, but the present application is not limited to the specific details in the above embodiment. Within the scope of the claims and technical concepts of the present application, the technical solutions of the present application can be modified and changed in many ways, and these simple modifications all belong to the protection scope of the present application.

Claims

1. A waterproofing repair material for high-speed railway ballastless track slab pouring holes, characterized in that, The composition by weight includes 400-450 parts cement, 350-400 parts fine aggregate, 20-40 parts expansion component, 50-100 parts active admixture, 20-50 parts dispersible latex powder, 2-5 parts waterproofing agent, 1-3 parts thixotropic agent, 1-2 parts polyvinyl alcohol fiber, and 0.5-1 parts thickener. The preparation method of the waterproofing agent is as follows: Polyvinyl alcohol was used to prepare a polyvinyl alcohol aqueous solution; nano-silica was mixed with an ethanol aqueous solution and polydimethylsiloxane was added to obtain a mixed solution; The polyvinyl alcohol aqueous solution and the mixture are mixed and stirred at 1000-2000 r / min for 40-80 min to obtain a composite dispersion. The dispersion is dried at 40-80℃ for 8-12 h, cooled, and ground into powder to obtain the waterproofing agent product with a fineness of 300-350 nm. The mass ratio of polyvinyl alcohol, nano silica and polydimethylsiloxane is (2-4):(2-4):(85-100).

2. The anti-permeation waterproof repair material for the perfusion hole of the high-speed rail ballastless track slab according to claim 1, characterized in that, The mass ratio of polyvinyl alcohol, nano-silica, and polydimethylsiloxane is 3.85:3.75:

100.

3. The anti-permeable waterproof repair material for the perfusion hole of the high-speed rail ballastless track plate according to claim 2, characterized in that, The polyvinyl alcohol aqueous solution has a mass fraction of 5%; the mass ratio of the nano-silica to the 75% ethanol aqueous solution is 1:

3.

4. The anti-permeable waterproof repair material for the perfusion hole of the high-speed rail ballastless track plate according to claim 1, characterized in that, The composition by weight includes 450 parts cement, 400 parts fine aggregate, 40 parts expansion component, 90 parts active admixture, 20 parts dispersible latex powder, 2 parts waterproofing agent, 3 parts thixotropic agent, 1 part polyvinyl alcohol fiber, and 0.5 parts thickener.

5. A method for repairing a perfusion hole of a high-speed railway ballastless track slab, characterized in that, The waterproof and impermeable repair material according to any one of claims 1-4 is mixed evenly, and water is added at a water-to-material ratio of 0.06-0.08 to make a mixture, which is then used for the repair and grouting of the grouting holes of the ballastless track slab of high-speed railway.

6. The method according to claim 5, wherein the method is characterized by, Remove and clean the damaged loose concrete, aggregate particles and residual debris in and around the grouting hole to be repaired; Drill a hole in the bottom of the grouting hole to be repaired and vertically insert a first reinforcing bar; bend the upper part of the first reinforcing bar horizontally, and the top surface of the bend is higher than the bottom surface of the grouting hole to be repaired; weld a second reinforcing bar horizontally to the upper part of the first reinforcing bar; The mixture is poured into the injection hole to be repaired, so that the top of the mixture is higher than the surface of the track plate, and the repair is completed after curing.

7. The method according to claim 6, wherein the method is characterized by, The first reinforcing bar is inserted to a depth of 120-200mm, and the height difference between the top surface of the first reinforcing bar after bending and the bottom surface of the grouting hole to be repaired is 35-55mm; the top of the mixture is no more than 10mm above the surface of the track slab.

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